[Federal Register Volume 79, Number 189 (Tuesday, September 30, 2014)]
[Notices]
[Pages 58914-58945]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-22758]



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Vol. 79

Tuesday,

No. 189

September 30, 2014

Part III





 Department of Commerce





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 National Oceanic and Atmospheric Administration





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 Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to Conductor Pipe Installation Activities at 
Harmony Platform in Santa Barbara Channel Offshore of California; 
Notice

  Federal Register / Vol. 79, No. 189 / Tuesday, September 30, 2014 / 
Notices  

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD188


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Conductor Pipe Installation 
Activities at Harmony Platform in Santa Barbara Channel Offshore of 
California

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; issuance of an Incidental Take Authorization (ITA).

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SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) 
regulations, notification is hereby given that NMFS has issued an 
Incidental Harassment Authorization (IHA) to the ExxonMobil Production 
Company (ExxonMobil), a Division of ExxonMobil Corporation, to take 
marine mammals, by Level B harassment only, incidental to installing 
six conductor pipes via hydraulic hammer driving at the Harmony 
Platform, Santa Ynez Production Unit, located in the Santa Barbara 
Channel offshore of California.

DATES: Effective September 17, 2014, through September 16, 2015.

ADDRESSES: A copy of the final IHA and application are available by 
writing to Jolie Harrison, Supervisor, Incidental Take Program, Permits 
and Conservation Division, Office of Protected Resources, National 
Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 
20910, by telephoning the contacts listed here, or by visiting the 
Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
    NMFS prepared an Environmental Assessment (EA) in accordance with 
the National Environmental Policy Act (NEPA), which is also available 
at the same Internet address. NMFS also issued a Biological Opinion 
under section 7 of the Endangered Species Act (ESA) to evaluate the 
effects of the conductor pipe installation activities and IHA on marine 
species listed as threatened and endangered. Documents cited in this 
notice may be viewed, by appointment, during regular business hours, at 
the aforementioned address.

FOR FURTHER INFORMATION CONTACT: Howard Goldstein or Jolie Harrison, 
Office of Protected Resources, NMFS, 301-427-8401.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.), 
direct the Secretary of Commerce (Secretary) to allow, upon request, 
the incidental, but not intentional, taking of small numbers of marine 
mammals, by United States citizens who engage in a specified activity 
(other than commercial fishing) within a specified geographical region 
if certain findings are made and either regulations are issued or, if 
the taking is limited to harassment, a notice of a proposed 
authorization is provided to the public for review.
    An authorization for the incidental takings shall be granted if 
NMFS finds that the taking will have a negligible impact on the species 
or stock(s), and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``. . . an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

Summary of Request

    On March 3, 2014, NMFS received an application from ExxonMobil for 
the taking of marine mammals incidental to installing six conductor 
pipes by hydraulic hammering at the Harmony Platform, Santa Ynez 
Production Unit, in the Santa Barbara Channel offshore of California. 
Along with the IHA application, NMFS received an addendum titled 
``Assessment of Airborne and Underwater Noise from Pile Driving 
Activities at the Harmony Platform.'' NMFS determined that the 
application was adequate and complete on April 28, 2014.
    The project's estimated dates are from mid-September to mid-
December 2014, but the planned action could occur anytime within a 12-
month period from the effective date of the IHA. Acoustic stimuli 
(i.e., increased underwater and airborne sound) generated during the 
conductor pipe installation activities are likely to result in the take 
of marine mammals. Take, by Level B harassment only, of 32 species of 
marine mammals is anticipated to result from the activities.

Description of the Specified Activity

Overview

    ExxonMobil plans to install six conductor pipes by hydraulic 
hammering at the Harmony Platform, Santa Ynez Production Unit, in the 
Santa Barbara Channel offshore of California.

Dates and Duration

    ExxonMobil estimates that the planned conductor pipe installation 
activities will occur from mid-September to mid-December 2014, but the 
planned activities could occur anytime within a 12-month period from 
the effective date of the planned IHA. Precise scheduling is not 
presently available due to logistical and regulatory uncertainties. The 
estimated duration of the planned project is 91 days. Under normal 
working conditions, the planned project is expected to include 
approximately 84 days of installation activity on the Harmony Platform 
bounded by 7 days of project mobilization/demobilization activities. It 
will take approximately 14 days to install each conductor pipe (6 
conductors x 14 days = 84 days). Figure 2-1 of the IHA application 
includes a timeline of pile-driving activities over the approximate 
three month duration.

Specified Geographic Region

    Harmony Platform is located in the Santa Barbara Channel, which is 
approximately 100 km (54 nmi) long and 40 km (21.6 nmi) wide, situated 
between the Channel Islands and the east-west trending coastline of 
California. The Santa Barbara Channel is the site of several other 
producing oil fields, including Ellwood, Summerland, Carpinteria 
offshore, and Dos Cuadras. The Santa Barbara basin is the prominent 
feature of the Santa Barbara Channel, with sill depths of approximately 
250 m (820.2 ft) and 450 m (1,467.4 ft) at eastern and western 
entrances, respectively, with shallow (60 m or 196.9 ft) inter-island 
passages to the south. Harmony Platform's geographical position is 
34[deg] 22' 35.906'' North, 120[deg] 10' 04.486'' West, at a water 
depth of 366 m (1,200.8 ft) on the continental slope below a relatively

[[Page 58915]]

steep (7.5%) descent. The Harmony Platform is 43.5 km (27 miles) 
southwest of Santa Barbara, California (see Figure 1 of the IHA 
application). It is 4.7 km (2.5 nmi) from the shelf break, which is 
typically defined at the 100 m (328.1 ft) isobaths (USGS, 2009). It is 
3.3 km (1.8 nmi) from the nearest buffered 200 m (656.2 ft) contour, 
which has been noted for its association with higher recorded densities 
of cetacean species (Redfern et al., 2013). It is also located 10 to 15 
km (5.4 to 8.1 nmi) north of a common traffic route used by vessels to 
access the ports of Long Beach and Los Angeles. Figure 1-1 of the IHA 
application includes the location of the Harmony Platform, general site 
bathymetry, and Santa Barbara area boundaries.

Detailed Description of the Specified Activity

    ExxonMobil plans to install six conductor pipes by hydraulic 
hammering at Harmony Platform. The conductor pipe installation 
activities are estimated to occur from mid-September to mid-December 
2014, but the action could occur anytime within a 12-month period from 
the effective date of the IHA. Harmony Platform is located 10 
kilometers (km) (5.4 nautical miles [nmi]) off the coast of California, 
between Point Conception and the City of Santa Barbara. Harmony 
Platform is one of three offshore platforms in ExxonMobil's Santa Ynez 
Production Unit, and is located in the Hondo field (Lease OCS-P 0190) 
at a water depth of 336 meters (1,200.8 ft). Harmony Platform was 
installed on June 21, 1989 with the sole purpose of producing crude oil 
and gas condensate. It began production of crude oil, gas and gas 
condensate on December 30, 1993. A conductor pipe is installed prior to 
the commencement of drilling operations for oil and gas wells. It 
provides protection, stability/structural integrity, and a conduit for 
drill cuttings and drilling fluid to the platform. It also prevents 
unconsolidated sediment from caving into the wellbore, and provides 
structural support for the well loads. Drilling activities are 
currently ongoing at Harmony Platform utilizing the existing conductors 
and wells. The platform jacket structure (see Figure 1-2 of the IHA 
application) currently has conductors installed in 51 out of 60 slots, 
as approved by the Bureau of Ocean Energy Management (BOEM, formerly 
the Minerals Management Service [MMS]) in the original Development 
Production Plan. Addition of eight straight conductors at the Harmony 
Platform was approved by the Bureau of Safety and Environmental 
Enforcement (BSEE) on February 11, 2013 to maintain current production 
levels from the existing platform. Conductor installation with a 
hydraulic hammer is consistent with approved development plans, and is 
the same method that was used to install conductors on all three Santa 
Ynez Production Unit platforms from 1981 (Hondo) through 1993 (Harmony 
and Heritage). Pipe-driving the conductors is the only proven 
installation method that enables management of potential interferences 
with the existing platform infrastructure that will also reach the 
target depth. Non-pipe-driving conductor installation methods are not 
deemed feasible at this time due to increased risk to platform 
structural integrity, offset well collision, and shallow-hole 
broaching.
    The total length of a single conductor pipe is approximately 505 m 
(1,656.8 ft). Each conductor consists of multiple sections of 66.04 
centimeter (cm) (26 inch [in]) diameter steel pipe that will be 
sequentially welded end-to-end from an upper deck of the platform (see 
Figure 1-2 of the IHA application), and lowered into the 366 m water 
column through metal rings (conductor guides) affixed to the jacket 
structure that orient and guide the conductor. Once the conductor 
reaches the sediment surface, gravity-based penetration (i.e., the 
conductor will penetrate the seabed under its own weight) is expected 
to reach approximately 30 m (98.4 ft) below the seabed. A hydraulic 
hammer (S-90 IHC) with a manufacturer's specified energy range of 9 to 
90 kiloJoules (kJ) will be located on the drill deck and used to drive 
the conductor to a target depth of approximately 90 to 100 m (295.3 to 
328.1 ft) below the seabed; therefore, only roughly 60 m (196.9 ft) of 
each 505 m (1,656.8 ft) long conductor pipe will require hydraulic 
driving. The S-90 IHC hydraulic hammer will sit on the conductor 
throughout pile-driving operations, but a ram internal to the hammer 
will stroke back and forth using hydraulic pressure to impart energy to 
the conductor. No physical dropping of a weight will be employed to 
drive the conductor.
    The S-90 IHC hydraulic hammer has an estimated blow rate of about 
46 blows per minute. The portion of a complete conductor that must be 
actively driven (hammered) into the seafloor consists of 5 to 7 
sections, which are sequentially welded end-to-end. Setup and welding 
will take 3.5 to 7.3 hours per section, mostly depending on the type of 
welding equipment used (e.g., automated welder). Impact hammer pipe-
driving will take an estimated 2.5 to 3.3 hours for each section, 
depending primarily on sediment physical properties, which affect 
penetration rate. Complete installation of each conductor is estimated 
at approximately 14 days based on 24-hour (continuous) operations. 
Table 1-1 of the IHA application presents a summary of driving 
activities and estimated number of joints [requiring welding] for each 
conductor pipe). Figure 1-3 of the IHA application shows the estimated 
time in days for each of these activities that are required to install 
a single conductor pipe. ExxonMobil conservatively assumes that active 
hammering will be 3.3 hours, followed by 7.3 hours of hammer downtime 
(i.e., ``quiet time,'' a time at which other activities are performed 
in preparation for the next section of pile) over approximately 53 
hours (2.2 days) of the approximately 14 days required to install one 
conductor pipe. This schedule produces 4.125 days (99 hours) of 
cumulated hammer driving for all six conductors over the project 
duration. Figure 1-4 depicts the 3.3 hour pile-drive/7.3 hour downtime 
cycle for an isolated 24-hour period, showing a maximum of 9.4 hours of 
hammer driving. In the event that efficiencies produce a 2.5 hour 
drive/3.5 hour downtime cycle, a maximum of 10 hours of hammer pile-
driving could occur in a single 24-hour period. The complete 
installation of the conductor pipes is estimated at 14 days of 
continuous operation.

Table 1--Summary of Conductor Pipe Installation Activities and Associated Characteristics of Each Conductor Pipe
                                               at Harmony Platform
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                                                             Estimated                               Estimated
    Conductor pipe activity          Pipe length (m)         number of    Pile-driving  required     number of
                                                              joints                                 days \3\
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Installation level to sea level  49 (160.8 ft)                         4  No....................               2
Sea level to seafloor..........  366 (1,200.8 ft)                     28  No....................             5.6

[[Page 58916]]

 
From 0 to ~30 m below seafloor.  30 \1\ (98.4 ft)                      3  No....................             0.9
From ~30 m to ~90 m below        60 (196.9 ft)                    5 to 7  Yes \2\...............            0.69
 seafloor.
Hammer downtime................  NA                                   NA  No....................            1.52
Clean up and completion........  NA                                   NA  No....................             3.6
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\1\ Estimated range of gravity-based penetration.
\2\ See Figure 1-4 of the IHA application.
\3\ See Figure 1-3 of the IHA application.

    NMFS provided a detailed description of the planned activities in a 
previous notice for the proposed IHA (79 FR 36743, June 30, 2014). The 
activities to be conducted have not changed between the proposed IHA 
notice and this final notice announcing the issuance of the IHA. For a 
more detailed description of the authorized action, including site 
bathymetry and sediment physical characteristics, hydrodynamics and 
water column physical properties, platform and acoustic source 
specifications, metrics, characteristics of sound sources, predicted 
sound levels of impact hammer pile-driving, etc., the reader should 
refer to the notice of the proposed IHA (79 FR 36743, June 30, 2014), 
the IHA application, addendum, and associated documents referenced 
above this section.

Comments and Responses

    A notice of the proposed IHA for ExxonMobil's conductor pipe 
installation activities was published in the Federal Register on June 
30, 2014 (79 FR 36743). During the 30-day public comment period, NMFS 
received comments from approximately 4,700 private citizens (as 
supporters of SierraRise and Sierra Club), Center for Biological 
Diversity (CBD), California Coastal Commission (CCC), and the Marine 
Mammal Commission (Commission). The comments are online at: http://www.nmfs.noaa.gov/pr/permits/incidental/. Following are the substantive 
comments and NMFS's responses:

MMPA Concerns

    Comment 1: The Commission states that the densities used to 
estimate the numbers of takes were derived using two different methods. 
For humpback, blue, and fin whales, ExxonMobil and NMFS stated that 
they used densities from Redfern et al. (2013) because those data were 
derived in the same project area--the Santa Barbara Channel. However, 
the estimated densities for blue and fin whales in the Federal Register 
notice do not match the upper boundary of the density contours from 
Redfern et al. (2013), which are shown in Table 6-3 and 6-4 of 
ExxonMobil's IHA application. Those figures indicate that the density 
should be 0.006 whales/km\2\ (not 0.008) for blue whales and 0.0065 
whales/km\2\ (not 0.004) for fin whales. Therefore, the Commission 
recommends that NMFS revise the density estimates for blue and fin 
whales to reflect the density information from Redfern et al. (2013).
    Response: NMFS concurs with the Commission's recommendation. The 
densities of blue and fin whales in the IHA application and the notice 
of the proposed IHA (79 FR 36743, June 30, 2014) are slightly below the 
upper boundary contours displayed in Redfern et al. (2013). NMFS agrees 
that the density estimates should be 0.006 for the blue whale and 
0.0065 for the fin whale. These minor corrections to the density 
estimates have only a minor effect on the calculated takes by Level B 
harassment, as shown in the table below. However, NMFS has increased 
the authorized takes for fin and blue whales to account for group size.

 Table 2--Proposed and Corrected Density Estimates for Two of the Species/Stocks Proposed To Be Taken Incidental
                             to ExxonMobil's Conductor Pipe Installation Activities
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                                                                            Calculated  takes/
                                      Density estimates                      requested takes
                                        from Table 5 of      Corrected       from  Table 5 of      Corrected
               Species                   the Federal        density from       the  Federal    calculated  takes/
                                       Register notice     Redfern et al.    Register notice       authorized
                                       of the proposed         (2013)        of the proposed         takes
                                             IHA                                   IHA
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Fin whale (Balaenoptera physalus)...              0.004             0.0065            0.005/1          0.00392/2
Blue whale (Balaenoptera musculus)..              0.008              0.006            0.011/1         0.000362/2
----------------------------------------------------------------------------------------------------------------

    Comment 2: The Commission states that for the species/stocks that 
are derived from Redfern et al. (2013), ExxonMobil and NMFS derived 
density estimates by dividing each species/stock's abundance estimate 
by the area of the Santa Barbara Channel (12,593 km\2\). The abundance 
estimates used by NMFS (in Table 5 of the notice of the proposed IHA 
[79 FR 36743, June 30, 2014]) were different from those used by 
ExxonMobil (in Table 3-1 of its IHA application). Although the reason 
for this discrepancy is not provided, it appears to the Commission that 
the abundance estimates in Table 5 of the Federal Register notice of 
the proposed IHA (79 FR 36743, June 30, 2014) were taken from the NMFS 
2013 Pacific Stock Assessment Report (Carretta et al., 2013). However, 
NMFS's derived density estimates were incorrect for four of the species 
identified. Table 3 (below) lists the four marine mammal species in 
question, NMFS's density estimates, and the Commission's corrected 
densities, based on the abundance estimates provided by NMFS in Table 5 
of the Federal Register notice of the proposed IHA (79 FR 36743, June 
30, 2014).

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Table 3--Proposed and Corrected Density Estimates, in Animals/km\2\, for
      Four of the Species/Stocks Proposed To Be Taken Incidental to
           ExxonMobil's Conductor Pipe Installation Activities
------------------------------------------------------------------------
                                                      Corrected  density
                                  Density  estimates  estimates, derived
                                   from  Table 5 of     from  abundance
                                     the  Federal        estimates in
             Species               Register  notice     Table 5 of the
                                   of the  proposed    Federal Register
                                          IHA            notice of the
                                                         proposed IHA
------------------------------------------------------------------------
Gray whale......................              0.5067               1.519
Cuvier's beaked whale...........                0.17               0.523
Mesoplodon spp..................                0.08               0.055
Bottlenose dolphin..............                0.11               0.080
------------------------------------------------------------------------

    Therefore, the Commission recommends that NMFS revise the density 
estimates for gray whales, Cuvier's beaked whales, Mesoplodon spp., and 
common bottlenose dolphins to reflect the best available abundance 
estimates from Carretta et al. (2013); the corrected density estimates 
should then be used in NMFS's revised take estimates.
    Response: The differences in the calculated densities reported in 
the IHA application (Tables 3-1 and 6-1 and the notice of the proposed 
IHA (79 FR 36743, June 30, 2014) were largely due to differences in 
abundance estimates and/or assumptions on seasonal variability (gray 
whale only), or due to combining abundance estimates of closely related 
stocks of selected species (e.g., killer whales). Where available, NMFS 
uses the abundance estimates for NMFS 2013 Pacific Stock Assessment 
Report (Caretta et al., 2013). Therefore, NMFS concurs with the 
Commission's recommendation regarding gray whales, Cuvier's beaked 
whales, Mesoplodon spp. beaked whales, and bottlenose dolphins, and has 
revised the abundance estimates and associated calculated and corrected 
density estimates. NMFS notes that these corrections produce little or 
no change in the number of calculated takes by Level B harassment for 
each of the identified species. An explanation of the density estimates 
and authorized take for each of the four species referenced in the 
Commission's comments follows:
     The gray whale density in the notice of the proposed IHA 
(79 FR 36743, June 30, 2014) is incorrect and should be approximately 
1.5, based on the NMFS 2013 Stock Abundance Report. However, the 
corrected density estimate produces no change in the estimated take of 
10 animals, which was increased (made more conservative based on group 
size and the schedule moving into the fall season, which is a higher 
density time period to account for the southward migration.
     The Cuvier's beaked whale density estimate in the notice 
of the proposed IHA (79 FR 36743, June 30, 2014) is incorrect and 
should be approximately 0.523. The notice of the proposed IHA also gave 
an incorrect abundance estimate for this species (6,950). The abundance 
of Cuvier's beaked whale abundance is 6,590 based on NMFS 2013 Stock 
Abundance Report (Caretta et al., 2013). Based on the corrected density 
estimate of 0.523 and a corrected abundance estimate of 6,590 animals, 
NMFS estimates that approximately 4 animals may be taken.
     NMFS provided a density estimate of 0.08 for the 
Mesoplodon spp. beaked whale in the notice of the proposed IHA (79 FR 
36743, June 30, 2014) based on an abundance of 1,024. Using the 
abundance estimate of 694 in the NMFS 2013 Stock Assessment Report, 
NMFS agrees with the Commission that the density estimate is 0.0551. 
This produces an estimated calculated take of approximately 1 animal 
using either abundance estimate. However, NMFS is authorizing take of 2 
animals based on group size.
     The bottlenose dolphin density estimate in the notice of 
the proposed IHA (79 FR 36743, June 30, 2014) is incorrect and should 
be approximately 0.08, based on the offshore abundance of the stock. 
Common bottlenose dolphin densities in the IHA application and notice 
of the proposed IHA (79 FR 36743, June 30, 2014) were 0.11 based on an 
abundance of 1,329, derived from combining the coastal and offshore 
stocks (323 + 1,006). However, California coastal bottlenose dolphins 
are found within one km (0.54 nmi) of shore primarily from Point 
Conception south into Mexican waters, at least as far south as San 
Quintin, Mexico; therefore, we do not expect the coastal stock to be 
taken by the conductor pipe installation activities and do not consider 
this stock further in this analysis (Hansen, 1990; Caretta et al., 
1998; Defran and Weller, 1999). In southern California, animals are 
found within 500 m (0.27 nmi) of shoreline 99% of the time and within 
250 m (0.13 nmi) 90% of the time (Hanson and Defran, 1993). The 
original calculated take estimates for bottlenose dolphins was 0.15, 
based on a density of 0.11. The corrected calculated take estimate is 
0.4829, based on the corrected density of 0.0799. However, the 
corrected density estimate produces no change in the estimated take of 
10 animals, which was increased (made more conservative) based on group 
size.
    Comment 3: The Commission states that ExxonMobil estimated the 
numbers of marine mammal takes by multiplying the species specific 
densities by the area of the Level B harassment buffer zone (0.3188 
km\2\) and the duration of the proposed conductor pipe installation 
activities. ExxonMobil calculated the latter as a total of 4.125 days 
for all six conductor pipes, apparently by summing each period of 
proposed conductor pipe installation activities and then dividing that 
cumulative exposure time by 24 hours to determine the number of days of 
exposure. Because pipe-driving sessions are interspersed between 
periods of no pipe-driving, summing across only pipe-driving periods 
underestimates the number of days of actual exposure. Instead, 
ExxonMobil should have summed across the entire pipe-driving timeframe, 
which includes period of no pipe-driving to determine the number of 
days animals would be exposed, because each day of pipe-driving has the 
potential to expose either the same animals repeatedly or different 
animals.
    The Commission states that the take estimates should account for 
multiple days of exposure rather than aggregated hours of exposure. In 
this instance, ExxonMobil should have added 3.3 hours of estimated 
pile-driving per section to 7.3 hours of downtime per

[[Page 58918]]

section for a total of 10.6 hours per section of pipe. Multiplying that 
by the projected seven sections to be driven for each conductor pipe 
would result in a total of 74.2 hours, which when divided by 24 hours 
per day equated to 3.1 days of potential exposure per pipe. Using that 
method would yield a total of 18.6 days of potential exposure (3.1 days 
per conductor pipe multiplied by 6 pipes), which more accurately 
represents the total duration of proposed conductor pipe installation 
activities for all six conductor pipes. Accordingly, the Commission 
recommends that NMFS revise its take estimates for all species/stocks 
to account for the total number of days of potential exposure (i.e., 
18.6 days), ensuring a more accurate estimate of potential takes.
    The CBD also states that NMFS underestimates the impacts as the 
planned conductor pipe installation activities are intermittent and not 
continuous as described in the notice of the proposed IHA (79 FR 36743, 
June 30, 2014). Authorizing take based on this assumption 
underestimates actual take, which would occur over a much greater 
amount of time as it could impact communication and navigation of 
marine mammals in the action area.
    Response: NMFS concurs with the Commission's recommendations and 
has revised the take calculations to account for 18.6 days of potential 
exposure. See Table 7 for the updated re-calculated take estimates and 
authorized take numbers.
    Comment 4: The Commission states that ExxonMobil adjusted its take 
estimates by a factor of at least 10 for a number of species to account 
for group size. NMFS based its proposed take estimates on ExxonMobil's 
requested takes for all species except two--sperm whales and short-
beaked common dolphins. NMFS proposed takes for a single sperm whale 
and 45 common dolphins, derived directly from density estimates with no 
adjustment for group size. Those two species typically occur in groups 
that may exceed the requested numbers of takes. Sperm whales typically 
occur in groups of 2 to 10 whales (Barlow et al., 2005), and common 
dolphins occur in groups of hundreds to thousands of animals (Reeves et 
al., 2002). If those species were to be observed in the vicinity of the 
project area, they likely would occur in numbers that exceed the 
requested number of takes. That could result in actual takes exceeding 
the authorized numbers of takes and/or premature shut-down of the 
proposed activities. In other similar situations, NMFS has increased 
the requested number of takes of a particular species to reflect the 
mean group size of that species (e.g., Table 4 in 78 FR 33811). 
Therefore, to ensure that the requested numbers of takes reflect 
numbers of individuals of each species that may be observed in the 
project area, the Commission recommends that NMFS increase its 
estimated numbers of takes for sperm whales and short-beaked common 
dolphins to reflect the minimum typical group size for each species 
(i.e., at least 2 and 450 animals, respectively).
    Response: NMFS concurs with the Commission's recommendation and has 
increased the takes of sperm whales and short-beaked common dolphins 
from 1 and 45 to 2 and 450, respectively. NMFS has also increased the 
authorized take numbers for humpback (from 1 to 2), minke (from 1 to 
2), sei (from 1 to 2), fin (from 1 to 2), blue (from 1 to 2), Baird's 
beaked (from 1 to 6), Cuvier's beaked (from 1 to 4), Mesoplodon spp. 
(from 1 to 2), killer (from 1 to 10), and short-finned pilot whales 
(from 1 to 40) as well as northern right whale dolphins (from 1 to 100) 
to account for average group size (Jefferson et al., 2008).
    Comment 5: The CBD states that NMFS underestimates the harmful 
impact of the proposed conductor pipe installation activities on 
endangered blue whales. The Santa Barbara Channel is important blue 
whale habitat. The global blue whale population has been reduced by 
commercial whaling from over 300,000 to likely fewer than 10,000 
individuals. Blue whales off California are part of a population 
comprised of about 1,647 animals; scientists estimate that even three 
human-caused deaths each year will impede the recovery of the 
California population. Nine blue whales have died from collisions with 
ships from 2007 to 2011; this means that human-caused mortality of blue 
whales already exceeds the sustainable amount.
    Response: NMFS fully considered the potential impacts of the 
planned conductor pipe installation activities on endangered blue 
whales. As described in the notice of the proposed IHA (79 FR 36743, 
June 30, 2014), NMFS anticipates only low level disturbance of blue 
whales, if any, in the form of Level B harassment. NMFS is authorizing 
take of two blue whale by Level B harassment only; no injury, serious 
injury, or mortality is anticipated or authorized. The potential 
impacts of the conductor pipe installation activities are expected to 
be temporary and are is not expected to have adverse consequences on 
the affected stock, including reductions in reproduction, numbers, or 
distribution that might appreciably reduce the stock's likelihood of 
surviving and recovering in the wild.
    NMFS's Office of Protected Resources, Permits and Conservation 
Division, also initiated and engaged in formal consultation under 
section 7 of the ESA with NMFS's West Coast Regional Office, Protected 
Resources Division, on the issuance of an IHA under section 
101(a)(5)(D) of the MMPA for this activity. NMFS's West Coast Regional 
Office, Protected Resources Division issued a Biological Opinion 
addressing the effects of the proposed action on threatened and 
endangered species, including the blue whale. The Biological Opinion 
concluded that the proposed action is not likely to jeopardize the 
continued existence of the blue whale.
    Comment 6: The CBD states that blue whales congregate throughout 
the Santa Barbara Channel (it hosts the world's densest summer seasonal 
congregation), and Harmony Platform is in the region that is an 
important area for blue whales. A recent tagging study determined the 
areas of highest use by blue whales off the West Coast. Researchers 
tagged 171 blue whales between 1993 and 2008, and the area of highest 
use was the western area in the Santa Barbara Channel (see Figure 1 of 
CBD's comments). The study showed that blue whales use the entire area 
of waters in southern California, but that the Santa Barbara Channel is 
the most heavily used. Between June and November, high densities of 
blue whales spend time feeding on the abundant planktonic krill in the 
area of this project (see Figure 2 of CBD's comments). The blue whales 
use the project area for foraging, and the conductor pipe installation 
activities will interfere with this important life function. Blue 
whales will be exposed to sounds that could have auditory damage, but 
could also be displaced from important foraging grounds.
    Response: Harmony Platform, which is located at 34 22'35.906'' 
North and 120 10'04.48 West, is on the coastal side of the shipping 
lane in the Santa Barbara Channel (see Figure 1-1 of the IHA 
application). Based on Figure 1 from CBD's letter (adapted from Irvine 
[2014]), this location is in the lowest density area of blue whales in 
the U.S. Exclusive Economic Zone near the Channel Islands based on 
satellite tracks, with only 1 to 5 blue whales observed from 1998 to 
2008. The highest density area (20 to 26 blue whales) shown in Figure 1 
of CBD's letter is located further offshore from the shipping channel, 
and roughly coincides with the area of highest krill density in the 
California Current reported by Santora et al. (2011), which is 
approximately 30 to 50 km (16.2 to 27

[[Page 58919]]

nmi) from Harmony Platform. These distribution correlations are 
expected given that krill comprise the majority of the blue whale's 
diet, and indicate that blue whales rarely forage or congregate within 
5 to 10 km (2.7 to 5.4 nmi) of Harmony Platform, which is well outside 
of the expected 325 m buffer zone for Level B harassment. NMFS 
anticipates only low level disturbance of blue whales, if any, in the 
form of Level B harassment, as Harmony Platform is located in an area 
of lowest blue whale density and second lowest krill density in the 
California Current (see Santora et al., 2011, Figure 5). NMFS does not 
expect the conductor pipe installation activities to displace blue 
whales from foraging grounds.
    Comment 7: CBD states that new science shows that blue whales, and 
possible other baleen whales, are highly susceptible to behavioral 
disturbance from noise pollution. The Goldbogen et al. (2013) study 
raises substantial concern because it demonstrates the potential 
impacts of high intensity noise on the essential life functions of blue 
whales. The study found that mid-frequency sonar can disrupt feeding 
and displace blue whales from high-quality prey patches, significantly 
impacting their foraging ecology, individual fitness, and population 
health. Even fairly low-received levels can have an adverse impact.
    Response: The Goldbogen et al. (2013) study analyzed behavioral 
responses of tagged blue whales in response to simulated military sonar 
and other mid-frequency sounds used during a controlled exposure 
experiment in feeding areas within the Southern California Bight. The 
study concluded that the responses of animals to mid-frequency sonar 
were complex, dependent on the behavioral state and sound exposure 
factors, and represented a general avoidance response of a perceived 
threat that appeared to subside quickly after sound exposure. 
ExxonMobil's conductor pipe installation activities would not generate 
the same sound characteristics as the military sonar and other mid-
frequency sounds that were used during those controlled exposure 
experiments. Moreover, the IHA requires ExxonMobil to implement 
monitoring and mitigation measures to avoid exposing marine mammals, 
including blue whales, to sounds levels that could have potential 
adverse impacts. As described in the notice of the proposed IHA (79 FR 
36743, June 30, 2014), NMFS anticipates only low level disturbance of 
marine mammals in the form of Level B harassment from ExxonMobil's 
activities. NMFS does not anticipate significant impacts to the 
foraging behavior, individual fitness, or population health of blue 
whales in the action area.
    Comment 8: The CBD states that the best available science indicates 
western North Pacific gray whales may be present in the survey area. 
Recently, a tagged western North Pacific gray whale traveled all the 
way from Sakhalin Island, Russia, to the west coast of North America, 
indicating that the population may merge with the eastern North Pacific 
population during migration and may therefore be taken by activity. 
There are currently an estimated 155 western North Pacific gray whales 
left in the world. With such low population numbers, the take of even 
one of these whales would have greater than negligible impacts on the 
species or stock.
    Response: Western North Pacific gray whales are not expected to 
occur in the action area. There is evidence of movement between 
``eastern'' and ``western'' populations of North Pacific gray whales, 
but the evidence thus far only supports low inter-area movements. For 
gray whales that migrate along the continental U.S., evidence from 
photo-identification work supports only seven confirmed western gray 
whale sightings (as well as a single satellite-tracked individual) ever 
in the central and eastern Pacific Ocean compared to roughly 20,000 
individuals composing the eastern North Pacific population, which has 
been tracked for decades (Mate et al., 2011; Burdin et al., 2011; 
Weller et al., 2011). These sightings occurred along Alaska, 
Washington, and Oregon, where foraging could occur. Urban et al. (2012) 
matched 13 individuals through photo-identification between summer 
feeding grounds in Russia and winter breeding lagoons in Mexico. The 
only motivation for an individual to continue further south (beyond 
foraging opportunities) is to participate in breeding and calving in 
lagoons of Baja California (Mexico) and the Gulf of California. 
However, numerous studies have found that genetic exchange between 
eastern and western populations is not occurring to a significant level 
(Leduc et al., 2002; Lang et al., 2004; Weller et al., 2004b; Lang et 
al., 2005; Swartz et al., 2006; Weller et al., 2006a; Weller et al., 
2007; Brownell Jr. et al., 2009; Kanda et al., 2010; Lang et al., 
2010b; Burdin et al., 2011). Moore and Weller (2012) determined the 
probability of taking a single gray whale from the western population 
during the proposed Makah Indian Tribe hunt as 0.014 to 0.051 during a 
single year. NMFS does not expect western North Pacific gray whales to 
occur in the action area due to the lack of documented trans-Pacific 
movement (particularly as far as the action area) as well as the lack 
of rationale for gray whales from the western population to move 
through the area.
    Comment 9: The CBD states that the North Pacific right whale is a 
potentially impacted species for which no take may be authorized. There 
are an estimated 25 to 30 individuals in the eastern stock of North 
Pacific right whales, making it the most highly endangered large whale 
in the world (Wade et al., 2011). Although NMFS notes that North 
Pacific right whales may be present in the project area, it assumes, 
without support, that no North Pacific right whales will be taken.
    Response: The North Pacific right whale is rarely found off the 
U.S. west coast. The majority of North Pacific right whale sightings 
from the eastern North Pacific stock occur in the Bering Sea and 
adjacent areas of the Aleutian Islands and Gulf of Alaska. Sightings of 
this species have been reported as far south as central Baja California 
in the eastern North Pacific, as far south as Hawaii in the central 
North Pacific, and as far north as the sub-Arctic waters of the Bering 
Sea and Sea of Okhotsk in the summer. Data from passive acoustic 
monitoring indicates that North Pacific right whales are present year-
round in the southeastern Bering Sea, with peaks in the late summer 
(August to September). Although individuals may travel south from the 
high-latitudes of the Bering Sea to lower-latitudes, animals that have 
been sighted in waters off Hawaii or tropical Mexico have been 
considered extralimital for this species (Brownell et al., 2001). The 
North Pacific right whale has not been observed near Harmony Platform. 
Therefore, no takes of North Pacific right whales are anticipated or 
authorized by NMFS. Although North Pacific right whales are not 
expected to occur in the action area, NMFS's Office of Protected 
Resources, Permits and Conservation Division also considered the 
conservation status, rarity, and habitat of ESA-listed marine mammals 
(including the North Pacific right whale) when developing mitigation 
measures for the conductor pipe installation activities. Included in 
the IHA are special procedures for situations or species of concern 
(see ``Mitigation'' section below). If a North Pacific right whale is 
visually sighted during the conductor pipe installation activities, the 
pipe-driving activities must be shut-down regardless of the distance of 
the animal(s) to the sound source. The pipe-driving will not resume 
firing until 30

[[Page 58920]]

minutes after the last documented whale visual sighting.
    Comment 10: The CBD states that sperm whales reach peak abundance 
in California from April through mid-June and from the end of August 
through mid-November, which is during the time of the proposed 
conductor pipe installation activities. Any take of a sperm whale would 
have greater than negligible impacts on the stock because NMFS must 
take into account the cumulative take of sperm whales from other 
activities, including incidental catch by fisheries. The California 
drift gillnet fishery, which operates primarily in southern California 
from August through January, took an estimated sixteen endangered sperm 
whales in the 2010 to 2011 fishing season (Caretta and Enriquez, 2012). 
Including both fishery and ship-strike mortality, the average annual 
rate of kill and serious injury is four sperm whales, exceeding the 
potential biological removal level of 1.5 (Caretta et al., 2012). With 
an estimated 971 sperm whales in the population, this level of 
anthropogenic take cannot be considered a negligible impact.
    Response: Sperm whale abundance varied off California between 1979/
1980 and 1991 (Barlow, 1994) and between 1991 and 2008 (Barlow and 
Forney, 2007). The most recent estimate from 2008 is the lowest to 
date, in sharp contrast to the highest abundance estimates obtained 
from NMFS's 2001 and 2005 surveys. However, there is no reason to 
believe that the population has declined; the most recent survey 
estimate likely reflects inter-annual variability in the study area. To 
date, there has not been a statistical analysis to detect trends in 
abundance. NMFS's 2013 Stock Assessment Report estimated a sperm whale 
abundance of 971 individuals for the California/Oregon/Washington 
stock. A new analysis by Moore and Barlow (in press) estimates a 
population abundance of approximately 21,31 animals (1,332 minimum).
    NMFS expects potential impacts by Level B harassment only to sperm 
whales; no injury, serious injury, or mortality is anticipated or 
authorized. The potential impacts are expected to be temporary and the 
action is not expected to have adverse consequences on the stock, 
including reductions in reproduction, numbers, or distribution that 
might appreciably reduce the stock's likelihood of surviving and 
recovering in the wild. Based on our analysis of the likely effects of 
the action on sperm whales and their habitat, and taking into 
consideration the implementation of the required monitoring and 
mitigation measures (see ``Mitigation'' below), NMFS finds that the 
take of small numbers of sperm whales by Level B harassment incidental 
to ExxonMobil's conductor pipe installation activities will have a 
negligible impact on the affected marine mammal species or stocks.
    NMFS's Office of Protected Resources, Permits and Conservation 
Division, also initiated and engaged in formal consultation under 
section 7 of the ESA with NMFS's West Coast Regional Office, Protected 
Resources Division, on the issuance of an IHA under section 
101(a)(5)(D) of the MMPA for this activity. NMFS's West Coast Regional 
Office, Protected Resources Division issued a Biological Opinion 
addressing the effects of the proposed action on threatened and 
endangered species, including the sperm whale. The Biological Opinion 
concluded that the proposed action is not likely to jeopardize the 
continued existence of the sperm whale.
    Comment 11: The CCC states that sea surface temperatures off of 
southern California and in the eastern north Pacific Ocean at large 
have been above normal for several months, and with an apparent El Nino 
event emerging in the equatorial Pacific Ocean later this year, are 
likely to remain elevated through the fall, winter, and into 2015. As a 
consequence of the unusually warm waters, marine mammal species more 
typical of subtropical latitudes have been sighted off of southern 
California and in the Santa Barbara Channel. These species may continue 
to be present in numbers and locations beyond those that can be 
reflected accurately by density estimates derived from long term survey 
and abundance datasets. These include cetaceans such as Bryde's whales 
(Balaenoptera brydei), false killer whales (Pseudorca crassidens), and 
short-finned pilot whales (Globicephala macrorhynchus), which have 
rarely been seen off the California coast in recent years. In light of 
these unusual environmental conditions, it may be necessary for NMFS to 
consider whether additional species could be exposed to the conductor 
pipe installation activities, and to revisit the species abundance 
assumptions underlying its incidental take calculations for the species 
already evaluated in the proposed IHA.
    Response: NMFS has received anecdotal reports from the public, 
whale watching companies, and other sources of recent sightings of 
Bryde's, false killer, and short-finned pilot whales. As discussed in 
the notice of the proposed IHA (79 FR 36743, June 30, 2014), these 
three species are generally found south of the Santa Barbara Channel 
and are unlikely to be found in the action area. Bryde's whales are 
extremely rare in the Southern California Bight, with fewer than ten 
confirmed sightings from August 2006 to September 2010 (Smultea et al., 
2012). NMFS West Coast Regional Office has received reports of up to 4 
individual Bryde's whales sighted in the summer of 2014 and has had a 
total of 12 sightings ever documented in the past. NMFS West Coast 
Regional Office has received reports of up to 40 short-finned pilot 
whales sighted off the Channel Islands and elsewhere. A group of 
approximately 50 short-finned pilot whales were sighted off the coast 
of Dana Point in Orange County in June 2014. A group of approximately 
40 to 70 false killer whales were sighted off the coast of Dana Point 
in March 2014. NMFS concurs with the CCC's recommendation and has 
authorized take, by Level B harassment, for Bryde's, false killer, and 
short-finned pilot whales based on the possibility of encountering a 
single individual Bryde's whale or a group of false killer and/or 
short-finned pilot whales in the action area of the planned conductor 
pipe installation activities at Harmony Platform. NMFS has also 
revisited the species abundance assumptions for all of the marine 
mammal species and has adjusted density estimates for those that occur 
in the California Current ecosystem. See Table 7 for the revised 
density estimates and authorized take numbers for these marine mammal 
species.
    Comment 12: The CBD is concerned with NMFS's conclusion to exclude 
consideration of Guadalupe fur seals, which are rarely sighted animals 
with ranges within the action area.
    Response: NMFS does not expect Guadalupe fur seals to be in the 
immediate action area or exposed to sounds generated by the conductor 
pipe installation activities. Guadalupe fur seals occur primarily near 
Guadalupe Island, Mexico, their primary breeding area. They are found 
north of the U.S.-Mexican border with a very small number of adults and 
pups observed on San Miguel Island (the western-most Channel Island in 
the Southern California Bight). Guadalupe fur seal strandings have 
occurred in California and north into Washington, which indicates that 
they must transit through southern California from Mexico to these 
areas where they have stranded. However, the encounter rate in the 
action area is considered to be very low. While they could potentially 
transit through the general area, NMFS considers it unlikely that they 
would be exposed to levels of sound associated

[[Page 58921]]

with take, given their rare occurrence in the area, the duration of the 
activities, and the size of the ensonified area.

Mitigation

    Comment 13: The CBD states that the mitigation measures are 
inadequate to ensure the least practicable adverse impact. If NMFS 
decides to approve the action it must require additional monitoring and 
mitigation measures to implement the least practicable impact on marine 
mammals.
    Response: NMFS's Office of Protected Resources, Permits and 
Conservation Division considered a number of mitigation measures before 
issuing the IHA, including measures proposed by ExxonMobil and 
additional measures recommended by the public. NMFS's Office of 
Protected Resources, Permits and Conservation Division has determined 
that the monitoring and mitigation measures required by the IHA provide 
the means of effecting the least practicable impact on species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.
    Comment 14: The CBD states that NMFS must fully analyze time-area 
restrictions as a mitigation measure. NMFS must not allow pipe-driving 
when blue whales aggregate in the Santa Barbara Channel during June 
through November. The western portion of the Santa Barbara Channel, 
where Harmony Platform is located, provides a core area for the blue 
whales, and pipe-driving should be restricted in this important habitat 
for blue whales. This closure should further be extended to avoid 
overlap with the presence of other whales.
    Response: NMFS disagrees with the CBD that time-area restrictions 
are necessary as a mitigation measure. The Harmony Platform is located 
at 34 22' 35.906'' North and 120 10' 04.48'' West, on the coastal side 
of the shipping lane in the Santa Barbara Channel (see Figure 1 of the 
IHA application). Based on Figure 1 in CBD's comment letter (adapted 
from Irvine, 2014), this location is in the lowest density of blue 
whales in the U.S. Exclusive Economic Zone near the Channel Islands 
based on satellite tracks, with only 1 to 5 blue whales observed from 
1998 to 2008 (yellow zone in Figure 1). The highest density area shown 
in Figure 1 (20 to 26 blue whales) is located further offshore from the 
shipping lane, and roughly coincides with the area of highest krill 
density in the California Current reported by Santora et al. (2011), 
which is approximately 30 to 50 km from Harmony Platform. These 
distribution correlations are expected given that krill comprise the 
majority of the blue whale's diet, and indicate that blue whales rarely 
forage or congregate within 5 to 10 km of Harmony Platform. Therefore, 
given that the areas of highest blue whale density and krill density 
near the Channel Islands are well outside the 325 m buffer zone for the 
pipe-driving activities, NMFS disagrees that time-area restrictions for 
the blue whale are necessary.
    Comment 16: The CBD states that NMFS must fully analyze larger 
exclusion zones as a mitigation measure. The use of more accurate 
thresholds would lead to larger exclusion zones. Additionally, the 
modeled distances disagree with measured sound levels for other pile-
driving activities. The exclusion zone of 3.5 m for pinnipeds and 10 m 
for cetaceans is woefully inadequate to mitigate Level A harassment. 
Bailey et al. (2010) measured 205 dB of broadband sound at 10 m from 
the pile-driving source. While the source was louder at 226 dB in that 
study, it indicates that the exclusion zone should be much larger.
    Response: NMFS disagrees with the CBD's comment. For a response to 
CBD's comment regarding NMFS' thresholds for Level A harassment, see 
the response to comment 21 (below) X. NMFS and ExxonMobil are not aware 
of any available in-situ measurements of underwater sound using a 90 kJ 
impact hammer with a 66 cm (26 in) diameter steel, 426.7 to 457.2 m 
(1,400 to 1,500 ft) pipe, in which case, acoustic modeling is an 
appropriate and oft-used scientifically defensible method available to 
estimate the buffer and exclusion zones established for potential 
impact and mitigation purposes. A detailed acoustic modeling report by 
JASCO titled ``Assessment of Airborne and Underwater Noise from Pile 
Driving Activities at the Harmony Platform'' was provided to NMFS with 
the IHA application, and includes detailed information on the computer 
model, uncertainties, and associated input parameters used to calculate 
distance to the buffer (Level B harassment) and exclusion (Level A 
harassment) zones. NMFS evaluated the report and determined that it 
provided sufficient support to establish predicted buffer and exclusion 
zones. Moreover, these predicted underwater and in-air sound levels 
will be assessed for accuracy when the monitoring data is analyzed 
after installation of the first conductor pipe, and the buffer and 
exclusion zones will be revised as necessary for the installation of 
the remaining pipes based on the results of the sound source 
verification.
    Bailey et al. (2010) assessed the potential effects of underwater 
noise levels during pile-driving at an offshore windfarm on marine 
mammals; however, the piles and pile-driving technical details as well 
as the sound analysis in that study are different than those planned to 
be used during ExxonMobil's conductor pipe installation activities. The 
Bailey et al. (2010) study was conducted for the installation of wind 
turbines using much shorter ``piles'' in water depths of approximately 
40 m (131.2 ft) (hammer specifications unknown); therefore, the 
underwater and in-air noise estimates and corresponding buffer and 
exclusion zones are not comparable between the two projects. This is 
because underwater sound propagation is a function of sound source 
energy and frequency, water depth and physical structure (e.g., 
salinity, temperature), bottom sediment type (hardness, porosity), and 
pipe material (e.g., steel, concrete) and size; all of which differ 
between the Bailey et al. (2010) site and the Harmony Platform site.
    Comment 16: The CBD states that NMFS must fully analyze air bubble 
curtains, which can reduce sound by 20 to 30 dB depending on their 
design, or explore the use of other noise reduction technologies (e.g., 
pile caps, dewatered cofferdams, and other physical barriers) for 
mitigating underwater sound from impact hammer pipe-driving.
    Response: NMFS and ExxonMobil evaluated the potential use of air 
bubble curtains to reduce the underwater sound generated during pipe-
driving activities in a water depth of 365.8 m (1,200 ft). The use of 
an air bubble curtain is not feasible due to interference of the jacket 
infrastructure at Harmony Platform, and the water depth and current 
speed (greater than 10 meters per second) at the activity site, which 
prevents the ability to maintain a constant air bubble density along 
the conductor length that would be effective at reducing underwater 
sound from the conductor pipe installation activities. The conductor 
pipes are being installed in 365.8 m of water through 76.2 cm (30 in) 
guides that are attached to structural members on the Harmony Platform; 
therefore, an air bubble curtain would be ineffective at reducing the 
output sound level, as bubbles would be dispersed and carried by 
currents away from the pipe and redirected by interference from the 
surrounding jacket members and conductor infrastructure. Because the 
conductors pass through 365.8 m of water column, another issue that 
eliminated this sound reduction

[[Page 58922]]

technique from consideration was that the air nozzles used to generate 
the air bubbles would most likely freeze-up before reaching the sea 
bottom due to the pressure and cold temperatures of the water, which 
would render the air bubble curtain ineffective. All known applications 
of air bubble curtains that have effectively reduced sound by 20 to 30 
dB have been used at depths shallower than 365.8 m and in waters with 
current velocities that are less than those commonly encountered in 
Santa Barbara Channel.
    NMFS and ExxonMobil also evaluated the potential use of a dewatered 
cofferdam to reduce the underwater sound generated during conductor 
pipe installation activities. The installation of a dewatered cofferdam 
around each conductor installation is not feasible due to the 365.8 ft 
water depth and corresponding pressure. In addition, each conductor has 
a limited footprint and has subsea interference from the jacket 
infrastructure. Also, a cofferdam would have to be driven into the sea 
bottom at a depth of 365.8 m to provide structural stability and 
protection from water currents, which would create additional potential 
impacts to marine mammals in the action area.
    NMFS and ExxonMobil also explored a physical noise abatement 
technology using flexible air-filled resonators that are lowered in 
multiple long hoses along the sides of each conductor prior to 
conductor pipe installation activities. The resonators would be filled 
with air in a hose-like structure that would close the gap around the 
conductors. This technology is not fully developed, and the scale of 
this noise abatement system would be unprecedented and impossible to 
install around Harmony Platform. The deepest known noise abatement 
system was installed in approximately 36.6 m (120 ft) of water, which 
is just one tenth of the depth where the planned conductor pipe 
installation activities will occur. This technology also has the same 
limitations as a bubble curtain, in that it uses air as the delivery 
system to fill the resonator and attenuate sound. At a water depth of 
365.8 m, air would likely form hydrates prior to filling the 
resonators, which would render this approach ineffective.
    Comment 17: The CBD states that NMFS must fully analyze and should 
restrict conductor pipe installation activities so that they do not 
occur during low visibility. The action is a 24-hour, continuous 
activity with pipe-driving potentially happening at night and during 
low visibility. The PSOs are ineffective at night and during low 
visibility. This means that during those times the exclusion zone will 
not be effective in mitigating take by Level A harassment. Furthermore, 
artificial lighting, while better for PSOs, brings hazards to migratory 
birds.
    Response: NMFS disagrees with the CBD's comment. The IHA does 
consider and address conductor pipe installation activities during low-
visibility and nighttime conditions. If inclement weather conditions 
(i.e., fog, rain, or rough Beaufort sea state) limit or impair PSO's 
visibility of the water's surface to less than 30.5 m (100 ft) within 
the action area, all noise-generating conductor pipe installation 
activities must be stopped until visibility improves. To facilitate 
visual monitoring during non-daylight hours, the exclusion zones must 
be illuminated by lights to allow for more effective viewing of the 
area by the PSO on-duty.
    ExxonMobil is providing artificial lighting for conductor pipe 
installation activities during nighttime and low visibility operations 
at the +15 ft level of the Harmony Platform that will provide adequate 
visibility to allow observation of the 3.5 m and 10 m exclusion zones 
for pinnipeds and cetaceans, respectively, as well as the surrounding 
areas. The lighting will only be on for those periods when conductor 
pipes are being driven at night or during periods of low visibility 
which typically occur for only a short period of time during the 
activities using the impact hammer. The artificial lighting that will 
be installed will have light shields attached to direct the light 
downward toward the water. Note that the Harmony Platform has existing 
lighting to allow for safe operations and to comply with regulations. 
ExxonMobil will continue its current monitoring practices throughout 
the planned conductor pipe installation activities, and will note any 
increase in bird activity during nighttime operations.

Monitoring and Reporting

    Comment 18: The Commission states that the accurate 
characterization of the sizes of the buffer and exclusion zones is 
critical for implementing mitigation measures and estimating the 
numbers of animals taken. In the past, the Commission has recommended a 
rapid turnaround of the in-situ sound source verification analysis to 
ensure that buffer and exclusion zones are the appropriate size. 
However, in at least one instance, rapid turnaround has resulted in 
errors, as occurred with ION's measurements of source levels during its 
2012 Arctic in-ice survey. In that case, the size of the exclusion zone 
was decreased from that modeled based on erroneous field-report 
results. The error was not discovered until the end of the field 
season, when it was determined that the in-season adjustments resulted 
in unauthorized Level A harassment takes of bowhead whales. Since the 
purpose of sound source verification is to ensure protection of marine 
mammals, one way to reduce risk to marine mammals would be to allow 
only for expansion, but not contraction, of the buffer and/or exclusion 
zones after in-situ adjustment in the size of the buffer and/or 
exclusion zones if the size(s) of the estimated zones are determined to 
be too small. The CCC also supports an adaptive approach to adjusting 
the buffer and exclusion zones based on in-situ data collected during 
the sound source verification. The process of adjusting the zones 
should begin from a protective baseline.
    Response: Monitoring will be performed during all impact hammer 
pipe-driving operations. Hydrophones will be deployed prior to the 
start of impact hammer pipe-driving the first pipe section. Data will 
be collected and analyzed upon completion of the conductor pipe's last 
pipe section. Monitoring equipment will be redeployed prior to 
installation of the remaining five conductor pipes. Upon completion of 
the first conductor pipe, acoustic data will be retrieved from the near 
field (approximately 10 m) and far field (approximately 325 to 500 m) 
recorders, analyzed, and compared to the predicted rms radii distances 
for the buffer and exclusion zones. ExxonMobil will consult with NMFS 
prior to proceeding with conductor pipe installation activities in the 
event that acoustic field data indicate that predicted radii distances 
for the buffer and exclusion zones need to adjusted (either expanded or 
contracted). Distances will be recalculated using field data, and 
monitoring equipment will be redeployed at the corrected distances 
prior to installation of the remaining conductor pipes, following 
authorization from NMFS. The planned extended down period (non-
hammering) between the completion of the first pipe installation and 
the start of the second pipe installation will be used to determine the 
actual size of buffer and exclusion zones (i.e., Level B and Level A 
harassment zones) to ensure that the radii estimated from acoustic 
modeling are not too small.
    Comment 19: The CCC states that due to the uncertainties with 
modeling, site specific, and/or seasonal oceanographic conditions, they 
request being provided copies of the monitoring reports referenced in 
the notice of the proposed IHA (79 FR 36743, June 30, 2014) for

[[Page 58923]]

ExxonMobil's conductor pipe installation activities. If monitoring 
indicates impacts greater than anticipated, CCC intends to continue to 
work with NMFS to assure the activity can be modified accordingly to 
minimize effects on marine mammals.
    Response: NMFS will provide copies of the in-water and in-air 
monitoring and sound source verification report for ExxonMobil's 
conductor pipe installation activities to the CCC when the document has 
been completed (after the first conductor pipe has been installed and, 
the in-situ measurements taken). NMFS will also provide the final 90-
day monitoring report required by the IHA to the CCC and make it 
publicly available on our Web site at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha.

Acoustic Thresholds

    Comment 20: CBD states that NMFS's current 160 dB threshold for 
Level B harassment in the notice of the proposed IHA (79 FR 36743, June 
30, 2014) does not reflect the best available science and is not 
sufficiently conservative. CBD state that in particular, the 160 dB 
threshold is non-conservative, because the scientific literature 
establishes that behavioral disruption can occur at substantially lower 
received levels for some species.
    Response: NMFS's practice has been to apply the 160 dB received 
level threshold for underwater impulse sound levels to determine 
whether take by Level B harassment occurs. Specifically, NMFS derived 
the 160 dB threshold data from mother-calf pairs of migrating gray 
whales (Malme et al., 1983, 1984) and bowhead whales (Richardson et 
al., 1985, 1986) responding to airgun operations. NMFS acknowledge 
there is more recent information bearing on behavioral reactions to 
sound sources such as pile-driving, seismic airguns, sonars, 
electromechanical devices, etc., but those data only illustrate how 
complex and context-dependent the relationship is between the various 
sound sources, and do not, as a whole, invalidate the current 
threshold. Accordingly, it is not a matter of merely replacing the 
existing threshold with a new one. NMFS discussed the science on this 
issue qualitatively in our analysis of potential effects to marine 
mammals in the Federal Register notice of the proposed IHA (79 FR 
36743, June 30, 2014). NMFS is currently developing revised acoustic 
guidelines for assessing the effects of anthropogenic sound on marine 
mammals. Until NMFS finalizes these guidelines (a process that includes 
internal agency review, public notice and comment, and peer review), 
NMFS will continue to rely on the existing criteria for Level A and 
Level B harassment shown in Table 4 of the notice of the proposed IHA 
(79 FR 36743, June 30, 2014).
    As mentioned in the Federal Register notice of the proposed IHA (79 
FR 36743, June 30, 2014), NMFS expects that the onset for behavioral 
harassment is largely context dependent (e.g., behavioral state of the 
animals, distance from the sound source, etc.) when evaluating 
behavioral responses of marine mammals to acoustic sources. Although 
using a uniform sound pressure level of 160 dB for the onset of 
behavioral harassment for impulse noises may not capture all of the 
nuances of different marine mammal reactions to sound, it is an 
appropriate way to manage and regulate anthropogenic noise impacts on 
marine mammals until NMFS finalizes its acoustic guidelines.
    Comment 21: CBD states that NMFS's use of the 180 and 190 dB 
thresholds for estimating Level A harassment and the likelihood of 
temporary and/or permanent threshold shift do not consider the best 
available science and is not sufficiently conservative. CBD cites 
Kastak et al. (2008), Lucke et al. (2009), Wood et al. (2012) and 
Kajawa and Liberman (2009).
    Response: As explained in the notice of the proposed IHA (79 FR 
36743, June 30, 2014), ExxonMobil will be required to establish a 180 
and 190 dB re 1 [mu]Pa exclusion zone for marine mammals before the 
conductor pipe installation activities begin. NMFS expects that the 
required platform-based visual monitoring of the exclusion zones is 
appropriate to implement mitigation measures to prevent Level A 
harassment. If the PSOs observe marine mammals approaching the 
exclusion zone, ExxonMobil must shut-down pipe driving to ensure that 
the marine mammal does not approach the applicable exclusion radius. 
The avoidance behaviors discussed in the notice of the proposed IHA (79 
FR 36743, June 30, 2014) also supports our expectations that 
individuals will avoid exposure at higher levels.
    NMFS's current Level A thresholds, which identify levels above 
which PTS could be incurred, were designed to be precautionary in that 
they were based on levels were animals had incurred TTS. NMFS is 
currently working on finalizing acoustic guidance that will identify 
revised TTS and PTS thresholds that references the studies identified 
by CBD. In order to ensure the best possible product, the process for 
developing the revised thresholds includes both peer and public review 
(both of which have already occurred) and NMFS will begin applying the 
new thresholds once the peer and public input have been addressed and 
the acoustic guidance is finalized.
    Regarding the Lucke et al. (2009) study, the authors found a 
threshold shift (TS) of a harbor porpoise after exposing it to airgun 
noise (single pulse) with a received sound pressure level (SPL) at 
200.2 dB (peak-to-peak) re 1 [mu]Pa, which corresponds to a sound 
exposure level of 164.5 dB re 1 [mu]Pa\2\ s after integrating exposure. 
NMFS currently uses the root-mean-square (rms) of received SPL at 180 
dB and 190 dB re 1 [mu]Pa as the threshold above which permanent 
threshold shift (PTS) could occur for cetaceans and pinnipeds, 
respectively. Because the pipe-driving noise is a broadband impulse, 
one cannot directly extrapolate the equivalent of rms SPL from the 
reported peak-to-peak SPLs reported in Lucke et al. (2009). However, 
applying a conservative conversion factor of 16 dB for broadband 
signals from seismic surveys (Harris et al., 2001; McCauley et al., 
2000) to correct for the difference between peak-to-peak levels 
reported in Lucke et al. (2009) and rms SPLs; the rms SPL for TTS would 
be approximately 184 dB re 1 [mu]Pa, and the received levels associated 
with PTS (Level A harassment) would be higher. This is still above the 
current 180 dB rms re 1 [mu]Pa threshold for injury. Yet, NMFS 
recognizes that the temporary threshold shift (TTS) of harbor porpoise 
is lower than other cetacean species empirically tested (Finneran et 
al., 2002; Finneran and Schlundt, 2010; Kastelein et al., 2012). NMFS 
considered this information in the notice of the proposed IHA (79 FR 
36743, June 30, 2014).
    A Thompson et al. (1998) telemetry study on harbor (Phoca vitulina) 
and grey seals (Halichoerus grypus) suggested that avoidance and other 
behavioral reactions by individual seals to small airgun sources may at 
times be strong, but short-lived. The researchers conducted 1-hour 
controlled exposure experiments exposing individual seals fitted with 
telemetry devices to small airguns with a reported source level of 215-
224 dB re 1 [mu]Pa (peak-to-peak) (Thompson et al., 1998; Gordon et 
al., 2003). The researchers measured dive behavior, swim speed heart 
rate and stomach temperature (indicator for feeding), but they did not 
measure hearing threshold shift in the animals. The researchers 
observed startle responses, decreases in heart rate, and temporary 
cessation of feeding. In six out of eight trials, harbor seals 
exhibited strong avoidance behaviors, and swam

[[Page 58924]]

rapidly away from the source (Thompson et al., 1998; Gordon et al., 
2003). One seal showed no detectable response to the airguns, 
approaching within 300 m (984 ft) of the source (Gordon et al., 2003). 
However, they note that the behavioral responses were short-lived and 
the seals' behavior returned to normal after the trials (Thompson et 
al., 1998; Gordon et al., 2003). The study does not discuss temporary 
threshold shift or permanent threshold shift in harbor seals and the 
estimated rms SPL for this survey is approximately 200 dB re 1 [mu]Pa, 
well above NMFS's current 180 dB rms re 1 [mu]Pa threshold for injury 
for cetaceans and NMFS' current 190 dB rms re 1 [mu]Pa threshold for 
injury for pinnipeds (accounting for the fact that the rms sound 
pressure level (in dB) is typically 16 dB less than the peak-to-peak 
level).
    In a study on the effect of non-impulsive sound sources on marine 
mammal hearing, Kastak et al. (2008) exposed one harbor seal to an 
underwater 4.1 kHz pure tone fatiguing stimulus with a maximum received 
sound pressure of 184 dB re 1 [mu]Pa for 60 seconds (Kastak et al., 
2008; Finneran and Branstetter, 2013). A second 60-second exposure 
resulted in an estimated threshold shift of greater than 50 dB at a 
test frequency of 5.8 kHz (Kastak et al., 2008). The seal recovered at 
a rate of -10 dB per log (min). However, 2 months post-exposure, the 
researchers observed incomplete recovery from the initial threshold 
shift resulting in an apparent permanent threshold shift of 7 to 10 dB 
in the seal (Kastak et al., 2008). NMFS notes that pipe-driving using 
an impact hammer sound is an impulsive source, and the context of 
Kastak et al. (2008) study is related to the effect of non-impulsive 
sounds on marine mammals.
    NMFS also considered two other Kastak et al. (1999, 2005) studies. 
Kastak et al. (1999) reported TTS of approximately 4-5 dB in three 
species of pinnipeds (harbor seal, California sea lion, and northern 
elephant seal) after underwater exposure for approximately 20 minutes 
to sound with frequencies ranging from 100 to 2,000 Hz at received 
levels 60 to 75 dB above hearing threshold. This approach allowed 
similar effective exposure conditions to each of the subjects, but 
resulted in variable absolute exposure values depending on subject and 
test frequency. Recovery to near baseline levels was reported within 24 
hours of sound exposure. Kastak et al. (2005) followed up on their 
previous work, exposing the same test subjects to higher levels of 
sound for longer durations. The animals were exposed to octave-band 
sound for up to 50 minutes of net exposure. The study reported that the 
harbor seal experienced TTS of 6 dB after a 25-minute exposure to 2.5 
kHz of octave-band sound at 152 dB (183 dB SEL). The California sea 
lion demonstrated onset of TTS after exposure to 174 dB (206 dB SEL).
    NMFS acknowledges that PTS could occur if an animal experiences 
repeated exposures to TTS levels. However, an animal would need to stay 
very close to the sound source for an extended amount of time to incur 
a serious degree of PTS, which in this case would be highly unlikely 
due to the required mitigation measures in place to avoid Level A 
harassment and the expectation that a mobile marine mammal would 
generally avoid an area where received sound pulse levels exceed 160 dB 
re 1 [mu]Pa (rms) (review in Richardson et al., 1995; Southall et al., 
2007).
    NMFS also considered recent studies by Kujawa and Liberman (2009) 
and Lin et al. (2011). These studies found that despite completely 
reversible threshold shifts that leave cochlear sensory cells intact, 
large threshold shifts (40 to 50 dB) could cause synaptic level changes 
and delayed cochlear nerve degeneration in mice and guinea pigs, 
respectively. NMFS notes that the high level of TTS that led to the 
synaptic changes shown in these studies is in the range of the high 
degree of TTS that Southall et al. (2007) used to calculate PTS levels. 
It is not known whether smaller levels of TTS would lead to similar 
changes. NMFS, however, acknowledges the complexity of noise exposure 
on the nervous system, and will re-examine this issue as more data 
become available.
    In contrast, a recent study on bottlenose dolphins (Schlundt, et 
al., 2013) measured hearing thresholds at multiple frequencies to 
determine the amount of TTS induced before and after exposure to a 
sequence of impulses produced by a seismic airgun. The airgun volume 
and operating pressure varied from 40 to 150 in\3\ and 1,000 to 2,000 
psi, respectively. After three years and 180 sessions, the authors 
observed no significant TTS at any test frequency, for any combinations 
of airgun volume, pressure, or proximity to the dolphin during 
behavioral tests (Schlundt, et al., 2013). Schlundt et al. (2013) 
suggest that the potential for airguns (or in this case pipe-driving 
using an impact hammer) to cause hearing loss in dolphins is lower than 
previously predicted, perhaps as a result of the low-frequency content 
of airgun impulses compared to the high-frequency hearing ability of 
dolphins. Although the sounds from pipe-driving using an impact hammer 
are not equivalent to those produced by a seismic airgun, they are both 
considered impulse sounds.
    Comment 22: CBD states that NMFS must consider that even behavioral 
disturbance can amount to Level A take if it interferes with essential 
life functions.
    Response: NMFS notes that Level B take has been defined previously 
in this document and specifically relates to behavioral disturbance. 
NMFS acknowledge that behavioral harassment in certain contexts, or 
continued over long durations, may, in certain situations have impacts 
on health and fitness of marine mammals. The discussion of whether 
these more severse impacts on individuals (which could lead to 
population-level impacts) occur as a result of any particular project 
are included in the negligible impact analysis. They are also 
considered qualitatively in the development of mitigation measures, via 
consideration of biologically important areas in the analysis and for 
time-area closures, or other important factors. Please see the response 
to comment 21 for a discussion of studies addressing PTS (Level A 
harassment).
    Comment 23: CBD requested that NMFS use a behavioral threshold 
below 160 dB for estimating take based on results reported in Bain and 
Williams (2006), Clark and Gagnon (2006), MacLeod et al. (2006), Risch 
et al. (2012), and DeRuiter et al. (2013).
    Response: NMFS is constantly evaluating new science and how to best 
incorporate it into our decisions. This process involves careful 
consideration of new data and how it is best interpreted within the 
context of a given management framework. Each of these articles 
emphasizes the importance of context (e.g., behavioral state of the 
animals, distance from the sound source, etc.) in evaluating behavioral 
responses of marine mammals to acoustic sources.
    These papers and the studies discussed in the notice of the 
proposed IHA (79 FR 36743, June 30, 2014) note that there is 
variability in the behavioral responses of marine mammals to noise 
exposure. However, it is important to consider the context in 
predicting and observing the level and type of behavioral response to 
anthropogenic signals (Ellison et al., 2012). There are many studies 
showing that marine mammals do not show behavioral responses when 
exposed to multiple pulses at received levels at or above 160 dB re 1 
[micro]Pa (e.g., Malme et al., 1983; Malme et al., 1984; Richardson et 
al., 1986; Akamatsu et al., 1993; Madsen

[[Page 58925]]

and Mohl, 2000; Harris et al., 2001; Miller et al., 2005; and Weir, 
2008). And other studies show that whales continue important behaviors 
in the presence of seismic pulses (e.g., Richardson et al., 1986; 
McDonald et al., 1995; Greene et al., 1999a, 1999b; Nieukirk et al., 
2004; Smultea et al., 2004; Holst et al., 2005, 2006; Dunn and 
Hernandez, 2009).
    In a passive acoustic research program that mapped the soundscape 
in the North Atlantic, Clark and Gagnon (2006) reported that some fin 
whales stopped singing for an extended period starting soon after the 
onset of a seismic survey in the area. The study did not provide 
information on received levels or distance from the sound source. The 
authors could not determine whether or not the whales left the area 
ensonified by the survey, but the evidence suggests that most if not 
all singers remained in the area (Clark and Gagnon, 2006). Support for 
this statement comes from the fact that when the survey stopped 
temporarily, the whales resumed singing within a few hours and the 
number of singers increased with time (Clark and Gagnon, 2006). Also, 
they observed that one whale continued to sing while the seismic survey 
was actively operating (Figure 4; Clark and Gagnon, 2006).
    The authors conclude that there is not enough scientific knowledge 
to adequately evaluate whether or not these effects on singing or 
mating behaviors are significant or would alter survivorship or 
reproductive success (Clark and Gagnon, 2006). Thus, to address CBD's 
concerns related to the results of this action, it is important to note 
that ExxonMobil's action area is well away from any known breeding/
calving grounds for low frequency cetaceans, thereby reducing further 
the likelihood of causing an effect on marine mammals.
    MacLeod et al. (2006) discussed the possible displacement of fin 
and sei whales related to distribution patterns of the species during a 
large-scale seismic survey offshore the west coast of Scotland in 1998. 
The authors hypothesized about the relationship between the whale's 
absence and the concurrent seismic activity, but could not rule out 
other contributing factors (Macleod et al., 2006; Parsons et al., 
2009). NMFS would expect that marine mammals may briefly respond to 
underwater sound produced by the pipe-driving activities by slightly 
changing their behavior or relocating a short distance. Based on the 
best available information, NMFS expects short-term disturbance 
reactions that are confined to relatively small distances and durations 
(Thompson et al., 1998; Thompson et al., 2013), with no long-term 
effects on recruitment or survival.
    Risch et al. (2012) documented reductions in humpback whale 
(Megaptera novaeangliae) vocalizations in the Stellwagen Bank National 
Marine Sanctuary concurrent with transmissions of the Ocean Acoustic 
Waveguide Remote Sensing (OAWRS) low-frequency fish sensor system at 
distances of 200 km (108 nmi) from the source. The recorded OAWRS 
produced series of frequency modulated pulses and the signal received 
levels ranged from 88 to 110 dB re 1 [mu]Pa (Risch et al., 2012). The 
authors hypothesize that individuals did not leave the area but instead 
ceased singing and noted that the duration and frequency range of the 
OAWRS signals (a novel sound to the whales) were similar to those of 
natural humpback whale song components used during mating (Risch et 
al., 2012). Thus, the novelty of the sound to humpback whales in the 
study area provided a compelling contextual probability for the 
observed effects (Risch et al., 2012). However, the authors did not 
state or imply that these changes had long-term effects on individual 
animals or populations (Risch et al., 2012), nor did they necessarily 
rise to the level of an MMPA take. Thus, to address CBD's concerns 
related to the results of this study, NMFS again notes that the 
ExxonMobil's action area is well away from any known breeding/calving 
grounds for low frequency cetaceans, thereby reducing further the 
likelihood of causing an effect on marine mammals.
    With repeated exposure to sound, many marine mammals may habituate 
to the sound at least partially (Richardson & Wursig, 1997). Bain and 
Williams (2006) examined the effects of a large airgun array (maximum 
total discharge volume of 1,100 in\3\) on six species in shallow waters 
off British Columbia and Washington: harbor seal, California sea lion 
(Zalophus californianus), Steller sea lion (Eumetopias jubatus), gray 
whale (Eschrichtius robustus), Dall's porpoise (Phocoenoides dalli), 
and the harbor porpoise. Harbor porpoises showed ``apparent avoidance 
response'' at received levels less than 145 dB re 1 [mu]Pa at a 
distance of greater than 70 km (37.8 nmi) from the seismic source (Bain 
and Williams, 2006). However, the tendency for greater responsiveness 
by harbor porpoise is consistent with their relative responsiveness to 
boat traffic and some other acoustic sources (Richardson et al. 1995; 
Southall et al., 2007). In contrast, the authors reported that gray 
whales seemed to tolerate exposures to sound up to approximately 170 dB 
re 1 [mu]Pa (Bain and Williams, 2006) and Dall's porpoises occupied and 
tolerated areas receiving exposures of 170 to 180 dB re 1 [mu]Pa (Bain 
and Williams, 2006; Parsons et al., 2009). The authors observed several 
gray whales that moved away from the airguns toward deeper water where 
sound levels were higher due to propagation effects resulting in higher 
noise exposures (Bain and Williams, 2006). However, it is unclear 
whether their movements reflected a response to the sounds (Bain and 
Williams, 2006). Thus, the authors surmised that the gray whale data 
(i.e., voluntarily moving to areas where they are exposed to higher 
sound levels) are ambiguous at best because one expects the species to 
be the most sensitive to the low-frequency sound emanating from the 
airguns (Bain and Williams, 2006).
    DeRuiter et al. (2013) recently observed that beaked whales 
(considered a particularly sensitive species to sound) exposed to 
playbacks (i.e., simulated) of U.S. tactical mid-frequency sonar from 
89 to 127 dB re 1 [mu]Pa at close distances responded notably by 
altering their dive patterns. In contrast, individuals showed no 
behavioral responses when exposed to similar received levels from 
actual U.S. tactical mid-frequency sonar operated at much further 
distances (DeRuiter et al., 2013). As noted earlier, one must consider 
the importance of context (for example, the distance of a sound source 
from the animal) in predicting behavioral responses. Regarding the 
public comments submitted by Clark et al. (2012) in reference to NMFS's 
use of the current acoustic exposure criteria; please refer to our 
earlier response to CBD.
    None of these studies on the effects of airgun noise on marine 
mammals point to any associated mortalities, strandings, or permanent 
abandonment of habitat by marine mammals. Bain and Williams (2006) 
specifically conclude that ``. . . although behavioral changes were 
observed, the precautions utilized in the SHIPS survey did not result 
in any detectable marine mammal mortalities during the survey, nor were 
any reported subsequently by the regional marine mammal stranding 
network . . .'' The ExxonMobil's 160-dB threshold radius will likely 
not reach the threshold distances reported in these studies.
    Currently NMFS is in the process of revising its behavioral noise 
exposure criteria based on the best and most recent scientific 
information. NMFS will use these criteria to develop methodologies to 
predict behavioral responses of marine mammals exposed to sound 
associated with conductor pipe

[[Page 58926]]

installation activities (primary source impact hammer operations). 
Although using a uniform sound pressure level of 160-dB re 1 [mu]Pa for 
the onset of behavioral harassment for impulse noises may not capture 
all of the nuances of different marine mammal reactions to sound, it is 
an appropriate way to manage and regulate anthropogenic noise impacts 
on marine mammals until NMFS finalizes its acoustic guidelines.
    Comment 24: The CCC states that it applies a more conservative 
approach to permitting pile-driving in state waters and recommends 
using the model-generated 160-dB threshold as the initial exclusion 
zone that would trigger a shut-down of conductor pipe installation 
activities using the impact hammer if marine mammals are sighted by 
PSOs approaching or entering this area. The more protective 160 dB 
exclusion zone generated by modeling could subsequently be reduced if 
in-situ measurements taken during the sound source verification 
indicate that this is warranted. If use of the model-generated 160 dB 
threshold for this purpose was found to be infeasible, the CCC staff 
would recommend an alternate strategy of imposing an additional 
protective buffer to the model-generated 180 and 190 dB based exclusion 
zones.
    Response: NMFS expects that acoustic stimuli resulting from the 
impact hammer pipe-driving associated with the conductor pipe 
installation activities has the potential to result in Level B 
harassment of marine mammals. NMFS disagrees with the CCC's 
recommendation to use the model-generated 160 dB threshold for 
underwater sounds as the initial exclusion zone that would trigger a 
shut-down for all marine mammals. Current NMFS practice, regarding 
exposure of marine mammals to high-level underwater sounds is that 
cetaceans and pinnipeds exposed to impulsive sounds at or above 180 and 
190 dB (rms), respectively, have the potential to be injured (i.e., 
Level A harassment). NMFS considers the potential for Level B 
(behavioral) harassment to occur when marine mammals are exposed to 
sounds below injury thresholds but at or above the 160 dB (rms) 
threshold for impulse sounds (e.g., impact pile-driving) and the 120 dB 
(rms) threshold for continuous noise (e.g., vibratory pile-driving). No 
vibratory pile-driving is planned for ExxonMobil's planned activities 
in the Santa Barbara Channel.
    The CCC's recommendation to use the estimated 160 dB exclusion zone 
as a trigger for shut-down is inconsistent with existing NMFS practice, 
and would effectively expand the Level A harassment exclusion zone for 
cetaceans and pinnipeds. It should be noted that a much larger 
exclusion zone for triggering shut-downs of conductor pipe installation 
activities has the potential to result in operational delays which 
could extend impact hammer pipe-driving time and/or result of losing a 
conductor pipe because successful completion of installation relies on 
consistent movement of the steel pipe through the bed sediment.
    NMFS also disagrees with the CCC's recommendation regarding the use 
of a protective buffer to the model-generated 180 and 190 dB based 
exclusion zones. Monitoring will be performed during all impact hammer 
pipe-driving operations. Hydrophones will be deployed prior to the 
start of impact hammer pipe-driving the first pipe section. Data will 
be collected and analyzed upon completion of the conductor pipe's last 
pipe section. Monitoring equipment will be redeployed prior to 
installation of the remaining five conductor pipes. Upon completion of 
the first conductor pipe, acoustic data will be retrieved from the near 
field (approximately 10 m) and far field (approximately 325 to 500 m) 
recorders, analyzed, and compared to the predicted rms radii distances 
for the buffer and exclusion zones. ExxonMobil will consult with NMFS 
prior to proceeding with conductor pipe installation activities in the 
event that acoustic field data indicate that predicted radii distances 
for the buffer and exclusion zones need to adjusted (either expanded or 
contracted). Distances will be recalculated using field data, and 
monitoring equipment will be redeployed at the corrected distances 
prior to installation of the remaining conductor pipes, following 
authorization from NMFS. The planned extended down period (non-
hammering) between the completion of the first pipe installation and 
the start of the second pipe installation will be used to determine the 
actual size of buffer and exclusion zones (i.e., Level B and Level A 
harassment zones) to ensure that the radii estimated from acoustic 
modeling are not determined to be too small.
    NMFS and ExxonMobil acknowledges that in-situ measurements of the 
sound may not agree with the modeled acoustic data due to uncertainties 
and model limitations identified by the CCC; however, it is not 
possible to improve model accuracy without obtaining data from the 
field. For this reason, a sound source verification will be conducted 
during the driving of the impact hammer for the first conductor pipe. 
The data collected and analyzed will be used to establish more accurate 
buffer and exclusion zones, and refine the acoustic model, if needed, 
before installation of the second conductor pipe begins.
    Finally, the CCC cites IHAs issued previously by NMFS as precedent 
for its recommended approach to establishing exclusion zones using the 
160 dB threshold as the trigger for implementing a shut-down procedure. 
Based on the citation provided by CCC (e.g., Naval Base Kitsap wharfs/
piers, 2011 and 2014), it is not clear whether the CCC believes there 
are additional examples of precedent or what specific action is 
referred to for 2011 (no references are provided in the CCC's letter, 
and NMFS issued two IHAs for construction activities at Naval Base 
Kitsap in 2011). However, referring to the 2014 example, in which NMFS 
issued an IHA to the Navy for take that could occur incidental to the 
third year of work associated with construction of a wharf (79 FR 
43429, July 25, 2014), the exclusion zone was in fact established on 
the basis of in-situ sound source measurements, following initial 
definition based on modeling results. This approach was identical to 
that described by NMFS in our notice of the proposed IHA (79 FR 36743, 
June 30, 2014), and the example does not provide supportive precedent 
for the CCC's recommendation.

Effects Analyses

    Comment 25: The CBD states that NMFS's evaluation in the notice of 
the proposed IHA (79 FR 36743, June 30, 2014) regarding the impacts 
from loss of prey on foraging are unknown; therefore, NMFS must get 
such data and analyze it to make its negligible impact determination.
    Response: NMFS disagrees with the CBD's comment. The anticipated 
effects on marine mammal habitat, including effects on potential prey 
and potential foraging habitat were described in the notice of the 
proposed IHA (79 FR 36743, June 30, 2014). Secondary effects, such as 
impacts to prey and habitat, are very important to NMFS's analysis and 
are considered in both the negligible impact analysis as well as 
qualitatively in the development of mitigation measures, via 
consideration of biologically important areas in the analysis and for 
time-area closures, or other important factors.

NEPA Concerns

    Comment 26: The CBD states that NMFS must comply fully with the 
National Environmental Policy Act (NEPA). The CBD states that NMFS 
notes that it will complete an EA prior to its decision on the IHA. 
Based on

[[Page 58927]]

multiple factors in NEPA's regulations, that the proposed activities do 
constitute a significant impact, and NMFS should prepare a full EIS. 
The purpose and need for the action is unclear and unnecessary. The IHA 
application does not fully explain the need and purpose of the 
additional conductor pipes. The notice of the proposed IHA (79 FR 
36743, June 30, 2014) states that the conductors are ``to maintain 
current production levels from the existing platform.'' This indicates 
that there is no need for the proposed action because maintenance of 
the current production levels should be able to be attained through the 
status quo.
    Response: In accordance with the National Environmental Policy Act 
(NEPA; 42 U.S.C. 4321 et seq.), NMFS completed an EA titled, 
``Environmental Assessment on the Issuance of an Incidental Harassment 
Authorization to ExxonMobil Production Company to Take Marine Mammals 
by Harassment Incidental to Conductor Pipe Installation Activities at 
Harmony Platform in the Santa Barbara Channel Offshore of California.''
    NMFS's EA includes all required components, including a brief 
discussion of need for the proposed action, a listing of the 
alternatives to the proposed action, a description of the affected 
environment, a brief discussion of the environmental impacts of the 
proposed action and alternatives, and sufficient evidence and analysis 
for determining whether to prepare an EIS or a Finding of No 
Significant Impact (FONSI).
    NOAA Administrative Order (NAO) 216-6 contains criteria for 
determining the significance of the impacts of a proposed action. In 
addition, the Council on Environmental Quality (CEQ) regulations at 40 
CFR 1508.27 state that the significance of an action should be analyzed 
both in terms of ``context'' and ``intensity.'' NMFS evaluated the 
significance of this action based on the NAO 216-6 criteria and CEQ's 
context and intensity criteria. Based on this evaluation, NMFS 
determined that issuance of this IHA to ExxonMobil would not 
significantly impact the quality of the human environment and issued a 
FONSI. Accordingly, preparation of an EIS is not necessary. NMFS's 
determination and evaluation of the NAO 216-6 criteria and CEQ's 
context and intensity criteria are contained within the FONSI issued 
for this action, which is available on NMFS's Web site at: http://www.nmfs.noaa.gov/pr/permits/incidental/.
    Comment 27: The CBD states NMFS must consider the additional 
suggested mitigation measures as alternatives in its NEPA analysis. An 
environmental review must ``inform decision-makers and the public of 
the reasonable alternatives which would avoid or minimize adverse 
impacts or enhance the quality of the human environment.'' NMFS must 
``rigorously explore and objectively evaluate all reasonable 
alternatives, and for alternatives which were eliminated from detailed 
study, briefly discuss the reasons for their having been eliminated.'' 
In addition, an agency must discuss measures designed to mitigate its 
action's impact on the environment. Accordingly, time-area closures, 
larger exclusion zones, low-visibility limitations, and noise reducing 
techniques should be considered in the range of alternatives.
    Response: In accordance with the National Environmental Policy Act 
(NEPA; 42 U.S.C. 4321 et seq.), NMFS completed an EA titled, 
``Environmental Assessment on the Issuance of an Incidental Harassment 
Authorization to ExxonMobil Production Company to Take Marine Mammals 
by Harassment Incidental to Conductor Pipe Installation Activities at 
Harmony Platform in the Santa Barbara Channel Offshore of California.'' 
The EA analyzes the impacts on the human environment of the issuance of 
an IHA by NMFS to ExxonMobil for conductor pipe installation activities 
at Harmony Platform in Santa Barbara Channel. It includes an evaluation 
of two alternatives:
    (1) Issuance of an IHA with mitigation measures, and
    (2) A no action alternative (i.e., do not issue an IHA and do not 
conduct the seismic survey).
    The EA also included a section on alternatives that were considered 
but eliminated from further consideration. NMFS considered whether 
other alternatives could meet the purpose and need and support 
ExxonMobil's conductor pipe installation activities. NMFS considered an 
alternative with additional mitigation measures; including the specific 
measures suggested by CBD, but eliminated that alternative from further 
consideration because the additional mitigation measures were 
considered not practicable or not likely to minimize adverse impacts. 
NMFS also considered an alternative that would allow for the issuance 
of an IHA with no required mitigation or monitoring but eliminated that 
alternative from further consideration, as it would not be in 
compliance with the MMPA and therefore would not meet the purpose and 
need.
    The EA will be available on the NMFS ITA Web site at: http://www.nmfs.noaa.gov/pr/permits/incidental/.
    Comment 29: The CBD states that NMFS has a duty to consider the 
indirect impacts of its action. Indirect effects ``are caused by the 
action and are later in time or farther removed in distance, but are 
still reasonably foreseeable.'' Although the purpose of the conductor 
pipes is unclear, any changes in production, drilling, waste, 
techniques, or lifetime of the oil and gas operations at Harmony 
Platform must be fully disclosed and adequately evaluated. If, for 
example, the conductor pipes will be used for or enable hydraulic 
fracturing or other unconventional well stimulation techniques then the 
environmental effects must evaluated.
    Response: Changes to the production, drilling, waste, techniques, 
or lifetime of the oil and gas operations at Harmony Platform are 
regulated by the Bureau of Ocean Energy Management and the Bureau of 
Safety and Environmental Enforcement. As stated in the notice of the 
proposed IHA (79 FR 36743, June 30, 2014), ExxonMobil requested an IHA 
from NMFS to take marine mammals, by harassment, incidental to 
installing six conductor pipes at Harmony Platform. In accordance with 
the National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.), 
NMFS completed an EA to evaluate the environmental effects of 
authorizing the take of marine mammals incidental to ExxonMobil's 
activities. The EA considers the direct, indirect, and cumulative 
impacts related to the issuance of an IHA authorizing the take of 
marine mammals incidental ExxonMobil's activities.
    NMFS notes that all produced fluids from ExxonMobil's offshore 
Santa Ynez Production Unit are routed to the onshore treating 
facilities located in Las Flores Canyon, where it is treated and re-
routed via pipeline, and discharged under an existing Environmental 
Protection Agency National Pollutant Discharge Elimination System 
(NPDES) permit. ExxonMobil has not used hydraulic fracturing on any of 
the wells on the three platforms in the Santa Ynez Production Unit 
located offshore of California. ExxonMobil has not and does not plan to 
use hydraulic fracturing or other unconventional well techniques in its 
offshore operations.
    Comment 29: The CBD states that NMFS must also look at the 
cumulative effects (past, present, and reasonably foreseeable future 
actions) of the action. For example, the Santa Barbara Channel is a 
busy shipping lane which means that the cumulative effects of noise

[[Page 58928]]

pollution from ship traffic and ship strikes must be evaluated. Whales 
fleeing pile-driving activities may be forced into shipping lanes to 
continue their foraging. Additionally, hydraulic fracturing activities 
from offshore oil and gas platforms in the area threaten endangered 
species and marine mammals in numerous ways--from oil spills and vessel 
strikes to air and water pollution. More than half of the platforms in 
federal waters discharge their wastewater, which can include toxic 
fracking chemicals, into the ocean. Harmony Platform alone is permitted 
to discharge over 33,000 barrels of wastewater into the ocean each 
year.
    Response: The NMFS EA analyzes the effects of NMFS's issuance of an 
IHA with mitigation and monitoring measures for the conductor pipe 
installation activities in light of other past, present, and reasonably 
foreseeable actions in the area including (1) other impact pipe-driving 
activities; (2) research activities; (3) military testing and training 
activities; (4) oil and gas activities; (5) vessel traffic, noise, and 
collisions; (6) commercial and recreational fishing; and (7) climate 
change. The EA concludes that the impacts of the issuance of an IHA for 
ExxonMobil's proposed conductor pipe installation activities in the 
Santa Barbara Channel offshore of California are expected to be no more 
than minor and short-term with no potential to contribute to 
cumulatively significant impacts.
    NMFS notes that Harmony Platform is located on the coastal side of 
the shipping lane in Santa Barbara Channel, while foraging areas are 
concentrated on the seaward side of the shipping lane; thus the whales 
would not be forced into the area busy with vessel traffic to forage. 
The shipping channel is located 12 to 14 km (6.5 to 7.6 nmi) from the 
Harmony Platform, and underwater sounds are within normal ambient 
ranges at the platform (e.g., 120 dB). As stated previously in this 
document, ExxonMobil does not perform hydraulic fracturing at Harmony 
Platform or elsewhere offshore of California. All produced water, 
including any fluids that are produced through the wells, are treated 
at the Las Flores Canyon facility and discharged as permitted under the 
Clean Water Act.

General Concerns

    Comment 30: Numerous private citizens, as supporters of SierraRise 
and Sierra Club, and the CBD, oppose the issuance of the IHA to 
ExxonMobil. They call on the government to stop destructive actions in 
the Santa Barbara Channel that lead to impairment, injury, and death of 
marine mammals. ExxonMobil's conductor pipe installation activities 
could lead to the death of many whales, otters, and more animals that 
are already threatened by toxic fracking fluids that have been dumped 
into their water. The commenters state that marine mammals deserve a 
safe, healthy ocean environment to live in, a healthy ocean is more 
important than more climate-killing offshore drilling.
    Response: As described in detail in the Federal Register notice for 
the proposed IHA (79 FR 36743, June 30, 2014), as well as in this 
document, NMFS anticipates only behavioral disturbance to occur during 
the conductor pipe installation activities. NMFS has determined that 
ExxonMobil's conductor pipe installation activities will not cause 
injury, serious injury, or mortality to marine mammals managed under 
NMFS's jurisdiction, and not takes by injury, serious injury, or 
mortality are authorized. Further, ExxonMobil is required to implement 
a number of mitigation and monitoring measures during the impact hammer 
pipe-driving activities, which are described below in the 
``Mitigation'' and ``Monitoring and Reporting'' sections. NMFS has 
determined that the required mitigation measures provide the means of 
effecting the least practicable impact on marine mammal species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance. The sea otter is 
managed by the U.S. Fish and Wildlife Service.
    Comment 31: The CBD states that NMFS should consider the 
environmental impacts of the activity on nearby marine protected areas 
(MPAs), reserves, and the Channel Islands National Marine Sanctuary 
that are located in the vicinity of the conductor pipe installation 
activities.
    Response: NMFS has considered environmental impacts of the 
conductor pipe installation activities on nearby MPAs as well as the 
Channel Islands National Marine Sanctuary. Individual mainland MPAs in 
southern California include: Point Conception State Marine Reserve 
(SMR), Kashtayit State Marine Conservation Area (SMCA), Naples SMCA, 
Campus Point SMCA, Goleta Slough SMCA, Point Dume SMCA, Point Dume SMR, 
Point Vicente SMCA, Abalone Cove SMCA, Bolsa Chica Basin SMCA, Upper 
Newport Bay SMCA, Crystal Cove SMCA, Laguna Beach SMR, Laguna Beach 
SMCA, Dana Point SMCA, Batiquitos Lagoon SMCA, Swami's SMCA, San Elijo 
Lagoon SMCA, San Diego-Scripps Coastal SMCA, Matlahuayl SMR, South La 
Jolla SMR, South La Jolla SMCA, Famosa Slough SMCA, Cabrillow SMR, and 
Tijuana River Mouth SMCA. Individual island MPAs include: Richardson 
Rock SMR and Federal MR, San Miguel Island Special Closure, Harris 
Point SMR and Federal MR, Judith Rock SMR, Carrington Point SMR, Skunk 
Point SMR, South Point SMR and Federal MR, Painted Cave SMCA, Gull 
Island SMR and Federal MR, Anacapa Island Special Closure, Anacapa 
Island SMR and Federal MR, Anacapa Island SMCA and Federal MCA, 
Footprint SMR and Federal MR, Begg Rock SMR, Santa Barbara Island MR 
and Federal MR, Arrow Point to Lion Head Point SMCA, Blue Cavern SMCA, 
Bird Rock SMCA, Long Point SMR, Casino Point SMCA, Lover's Cover SMCA, 
Farnsworth Onshore SMCA, Farnsworth Offshore SMCA, and Cat Harbor SMCA. 
The closest MPAs, which are Naples SMCA and Point Conception SMR, are 
over 18.5 km (10 nmi) east-southeast and 27.8 km (15 nmi) west-
northwest at its closest boundary to Harmony Platform, respectively. 
Sound levels generated during the planned conductor pipe installation 
activities will not have significant consequences on MPAs because all 
MPAs are a minimum of 18.5 km from the Harmony Platform and the 
platform is not in shallow water depths.
    The Channel Islands National Marine Sanctuary is about 25.9 km (14 
nmi) southwest at its closest boundary to Harmony Platform. NMFS has 
contacted Channel Islands National Marine Sanctuary regarding 
ExxonMobil's planned conductor pipe installation activities and the 
associated issuance of an IHA. NMFS has determined that a consultation 
under the National Marine Sanctuary Act is not necessary as the planned 
action is not anticipated to have impacts on sanctuary resources.
    Comment 32: The CBD states that noise from conductor pipe 
installation activities can impact EFH and NMFS must fully comply with 
its statutory obligation to consult on the impact of federal activities 
on essential fish habitat (EFH) under the Magnuson-Stevens Fishery 
Conservation and Management Act (MSA). The EFH consultation should 
include an evaluation of the effects of the action on EFH, proposed 
mitigation, and make conservation recommendations.
    Response: NMFS disagrees with the commenter's assessment. NMFS's 
issuance of an IHA and the mitigation and monitoring measures required 
by the IHA would not affect ocean and coastal habitat or EFH. 
Therefore, NMFS, Office of Protected Resources,

[[Page 58929]]

Permits and Conservation Division determined that an EFH consultation 
is not required.
    Comment 33: The CBD states that NMFS must comply fully with the 
Endangered Species Act (ESA) and develop a robust Biological Opinion 
based on the best available science. The proposed conductor pipe 
installation activities may have harmful impacts on ESA-listed marine 
mammals (including North Pacific right, humpback, sei, fin, blue, and 
sperm whales, as well as southern sea otters and Guadalupe fur seals), 
which must be fully and accurately vetted through the consultation 
process. Accordingly, NMFS must complete consultation and obtain any 
take authorization before authorizing the proposed activities. They 
further urge NMFS to establish more stringent mitigation measures to 
avoid adverse impacts to ESA-listed species.
    Response: Section 7(a)(2) of the ESA requires that each federal 
agency insure that any action authorized, funded, or carried out by 
such agency is not likely to jeopardize the continued existence of any 
endangered or threatened species or result in the destruction or 
adverse modification of critical habitat of such species. Of the 
species of marine mammals that may occur in the action area, several 
are listed as endangered under the ESA, including the North Pacific 
right, Western North Pacific gray, humpback, sei, fin, blue, and sperm 
whales as well as the Guadalupe fur seal. Although critical habitat is 
designated for the North Pacific right whale, no critical habitat for 
North Pacific right whales occurs in the action area. The North Pacific 
right whale critical habitat in the Pacific Ocean can be found online 
at: http://www.nmfs.noaa.gov/pr/pdfs/criticalhabitat/northpacificrightwhale.pdf.
    NMFS's Office of Protected Resources, Permits and Conservation 
Division, initiated and engaged in formal consultation under section 7 
of the ESA with NMFS's West Coast Regional Office, Protected Resources 
Division, on the issuance of an IHA under section 101(a)(5)(D) of the 
MMPA for this activity. NMFS's West Coast Regional Office, Protected 
Resources Division issued a Biological Opinion addressing the effects 
of the proposed actions on threatened and endangered species as well as 
designated critical habitat in September 2014. The Biological Opinion 
concluded that NMFS's issuance of an IHA to ExxonMobil is not likely to 
jeopardize the existence of any threatened and endangered species and 
would have no effect on critical habitat. NMFS's West Coast Regional 
Office, Protected Resources Division, relied on the best scientific and 
commercial data available in conducting its analysis.
    NMFS's Office of Protected Resources, Permits and Conservation 
Division also considered the conservation status and habitat of ESA-
listed marine mammals. Included in the IHA are special procedures for 
situations or species of concern (see ``Mitigation'' section below). If 
a North Pacific right whale is visually sighted during the conductor 
pipe installation activities, the pipe-driving activities must be shut-
down regardless of the distance of the animal(s) to the sound source. 
The pipe-driving will not resume firing until 30 minutes after the last 
documented whale visual sighting. Concentrations of humpback, sei, fin, 
blue, and/or sperm whales will be avoided if possible (i.e., exposing 
concentrations of animals to 160 dB), and the activities will be shut-
down if necessary. For purposes of the conductor pipe installation 
activities, a concentration or group of whales will consist of three or 
more individuals visually sighted that do not appear to be traveling 
(e.g., feeding, socializing, etc.). NMFS's West Coast Regional Office, 
Protected Resources Division, issued an Incidental Take Statement (ITS) 
incorporating the requirements of the IHA as Terms and Conditions of 
the ITS. Compliance with the ITS is likewise a mandatory requirement of 
the IHA. NMFS's Office of Protected Resources, Permits and Conservation 
Division has determined that the mitigation measures required by the 
IHA provide the means of effecting the least practicable impact on 
species or stocks and their habitat, including ESA-listed species.
    Comment 34: The CBD states that NMFS must comply fully with the 
Coastal Zone Management Act (CZMA). The CZMA requires that applicants 
for federal permits to conduct an activity affecting a natural resource 
of the coastal zone of a state ``shall provide in the application to 
the licensing or permitting agency a certification that the proposed 
activity complies with the enforceable policies of the state's approved 
program and that such activity will be conducted in a manner consistent 
with the program.'' CBD states that marine species that will be 
affected by the project are ``natural resources'' protected by 
California's coastal management program, and that California should be 
given the opportunity to review the IHA for consistency with their 
coastal management programs.
    Response: As the lead federal agency for the IHA, NMFS considered 
whether the action would have effects on the coastal resources of any 
state along the U.S. West Coast. As concluded in the notice of the 
proposed IHA (79 FR 36743, June 30, 2014), any potential impacts from 
the conductor pipe installation activities would mainly be to marine 
species in close proximity to the Harmony Platform and would be of a 
short duration and temporary in nature. The Harmony Platform is located 
at 34[deg] 22'35.906'' North and 120[deg]10'04.48'' West, which is 
located approximately 10 km (5.4 nmi) off the coast of California, in 
federal waters. NMFS discussed issuance of the IHA and ExxonMobil's 
planned conductor pipe installation activities with the California 
Coastal Commission. Therefore, NMFS has concluded that we have met all 
of the responsibilities under the CZMA.
    Comment 35: The CBD is concerned that ExxonMobil is not in full 
compliance with the Outer Continental Shelf Lands Act (OCSLA). The CBD 
states that NMFS provided no support for its statement that the 
proposed conductor pipe installation activities are considered in the 
existing Development and Production Plan.
    Response: The OCSLA is administered by the Department of the 
Interior. NMFS does not have the regulatory authority to permit 
ExxonMobil's activities under the OCSLA. As stated in the notice of the 
proposed IHA (79 FR 36743, June 30, 2014), ExxonMobil requested an IHA 
from NMFS to take marine mammals, by harassment, incidental to 
installing six conductor pipes at Harmony Platform in the Santa Barbara 
Channel. Consistent with its regulatory authority under the MMPA, NMFS 
determined that authorizing the take of small numbers of marine mammals 
by Level B harassment incidental to ExxonMobil's activities would have 
a negligible impact on marine mammals species or stocks and would not 
have an unmitigable adverse impact on the availability of species or 
stocks for taking for subsistence uses, and prescribed the permissible 
methods of taking by harassment pursuant such activity and other means 
of effecting the least practicable impact on species or stocks and 
their habitat.

Description of the Marine Mammals in the Area of the Specified Activity

    The marine mammals that generally occur in the planned action area 
belong to four taxonomic groups: mysticetes (baleen whales), 
odontocetes (toothed whales), pinnipeds (seals and sea lions), and 
fissipeds (sea otters). The marine mammal species that potentially 
occur within the Pacific Ocean in proximity to the action area in the 
Santa Barbara

[[Page 58930]]

Channel off the coast of California (ranging from Point Conception and 
south, including the entire Southern California Bight) include 31 
species of cetaceans (whales, dolphins, and porpoises) and 6 species of 
pinnipeds. The southern sea otter (Enhydra lutris nereis) is listed as 
threatened under the ESA and is managed by the U.S. Fish and Wildlife 
Service and is not considered further in this IHA notice.
    Marine mammal species listed as threatened or endangered under the 
U.S. Endangered Species Act of 1973 that could potentially occur in the 
action area (ESA; 16 U.S.C. 1531 et seq.), include the North Pacific 
right (Eubalaena japonica), Western North Pacific population gray 
(Eschrichtius robustus), humpback (Megaptera novaeangliae), sei 
(Balaenoptera borealis), fin (Balaenoptera physalus), blue 
(Balaenoptera musculus), and sperm (Physeter macrocephalus) whale as 
well as the Guadalupe fur seal (Arctocephalus townsendi). Of those 
threatened and endangered species, the humpback, sei, fin, blue, and 
sperm whale are likely to be encountered in the action area.
    Cetaceans occur throughout the Santa Barbara Channel action area, 
including nearby the Harmony Platform, from the surf zone to open ocean 
environments beyond the Channel Islands. Distribution is influenced by 
a number of factors, but primary among these are patterns of major 
ocean currents, bottom relief, and sea surface temperature. These 
physical oceanographic conditions affect prey abundance, which may 
attract marine mammals during periods of high productivity, and vice 
versa. Water movement is near continuous, varying seasonally, and is 
generally greatest from late spring to early fall in response to 
varying wind stress. This phenomenon is much greater in the western 
Santa Barbara Channel. This near continuous movement of water from the 
ocean bottom to the surface creates a nutrient-rich, highly productive 
environment for marine mammal prey (Jefferson et al., 2008). Most of 
the large cetaceans are migratory, but many small cetaceans do not 
undergo extensive migrations. Instead, they undergo local or regional 
dispersal, on a seasonal basis or in response to food availability. 
Population centers may shift on spatial scales exceeding 100 km (54 
nmi) over small time scales (days or weeks) (Dailey and Bonnell, 1993).
    Systematic surveys (1991 to 1993, 1996, 2001, 2005) in the southern 
California region have been carried out via aircraft (Carretta and 
Forney, 1993) and vessel (Ferguson and Barlow, 2001; Barlow, 2003) by 
NMFS. In addition, a vessel survey in the U.S. Exclusive Economic Zone 
(EEZ), and out to 556 km (300.2 nmi) offshore of California, Oregon, 
and Washington, was conducted in the summer and fall of 2005 by NMFS 
(Forney, 2007). Many other regional surveys have also been conducted 
(Carretta, 2003). Becker (2007) analyzed data from vessel surveys 
conducted since 1986, and compiled marine mammal densities. There are 
31 cetacean and 6 pinniped species with ranges that are known to occur 
in the Eastern North Pacific Ocean waters of the project area. These 
include the North Pacific right whale, dwarf sperm whale (Kogia sima), 
harbor porpoise (Phocoena phocoena), Steller sea lion (Eumatopias 
jubatus), and Guadalupe fur seal. However, these species are extremely 
rare, found in the Channel Islands, or are primarily found north or 
south of the Santa Barbara Channel, and are unlikely to be found in the 
action area. The harbor porpoise occurs north of Point Conception, 
California. Guadalupe fur seals are most common at Guadalupe Island, 
Mexico, which is their primary breeding ground (Melin and Delong, 
1999). Although adult and juvenile males have been observed at San 
Miguel Island, California, since the mid-1960's, and in the late 1990's 
a pup was born on the islands (Melin and Delong, 1999), more recent 
sightings are extremely rare. These species are not considered further 
in this document. Table 4 (below) presents information on the 
occurrence, abundance, distribution, population status, and 
conservation status of the species of marine mammals that may occur in 
the project area during September to December 2014.

 Table 4--The Habitat, Occurrence, Range, Regional Abundance, and Conservation Status of Marine Mammals That May Occur in or Near the Pipe Installation
                                              Project Area Off the Coast of California in the Pacific Ocean
                                      [See text and Tables 3-1 in ExxonMobil's IHA application for further details]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                Best population
             Species                    Habitat           Occurrence             Range        estimate (Minimum)        ESA \2\            MMPA \3\
                                                                                                      \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Mysticetes
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Pacific right whale         Coastal and         Rare..............  North Pacific       NA (26)--Eastern    EN................  D
 (Eubalaena japonica).             pelagic.                                Ocean between 20    North Pacific
                                                                           to 60[deg] North.   stock.
Gray whale (Eschrichtius          Coastal and shelf.  Transient during    North Pacific       19,126 (18,107)--   DL--Eastern North   NC--Eastern North
 robustus).                                            seasonal            Ocean, Gulf of      Eastern North       Pacific stock EN--  Pacific stock D--
                                                       migrations.         California to       Pacific stock 155   Western North       Western North
                                                                           Arctic--Eastern     (142)--Western      Pacific             Pacific
                                                                           North Pacific       North Pacific       population.         population
                                                                           stock.              population.
Humpback whale (Megaptera         Pelagic, nearshore  Seasonal,           Cosmopolitan......  1,918 (1,855)--     EN................  D
 novaeangliae).                    waters, and banks.  sightings near                          California/Oregon/
                                                       northern Channel                        Washington (CA/OR/
                                                       Islands.                                WA) stock.
Minke whale (Balaenoptera         Pelagic and         Less common in      Tropics and sub-    478 (202)--CA/OR/   NL................  NC
 acutorostrata).                   coastal.            summer, small       tropics to ice      WA stock.
                                                       number around       edges.
                                                       northern Channel
                                                       Islands.
Bryde's whale (Balaenoptera       Pelagic and         Rare, infrequent    Tropical and sub-   NA--No stock for    NL................  NC
 edeni).                           coastal.            summer off          tropical zones      CA/OR/WA.
                                                       California.         between 40[deg]
                                                                           North and 40[deg]
                                                                           South.

[[Page 58931]]

 
Sei whale (Balaenoptera           Primarily           Rare, infrequent    Tropical to polar   126 (83)--Eastern   EN................  D
 borealis).                        offshore, pelagic.  summer off          zones, favor mid-   North Pacific
                                                       California.         latitude            stock.
                                                                           temperate areas.
Fin whale (Balaenoptera           Continental slope,  Year-round          Tropical,           3,051 (2,598)--CA/  EN................  D
 physalus).                        pelagic.            presence.           temperate, and      OR/WA stock.
                                                                           polar zones of
                                                                           all oceans.
Blue whale (Balaenoptera          Pelagic, shelf,     Seasonal, arrive    Tropical waters to  1,647 (1,551)--     EN................  D
 musculus).                        coastal.            April to May,       pack ice edges.     Eastern North
                                                       common late-                            Pacific stock.
                                                       summer to fall
                                                       off Southern
                                                       California.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Odontocetes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale (Physeter             Pelagic, deep sea.  Common year-round,  Tropical waters to  971 (751)--CA/OR/   EN................  D
 macrocephalus).                                       more likely in      pack ice edges.     WA stock.
                                                       waters >1,000 m.
Pygmy sperm whale (Kogia          Pelagic, slope....  Seaward of 500 to   Tropical to warm    579 (271)--CA/OR/   NL................  NC
 breviceps).                                           1,000 m, Limited    temperate zones     WA stock.
                                                       sightings in        (temperate
                                                       Southern            preference).
                                                       California Bight.
Dwarf sperm whale (Kogia sima)..  Deep waters off     Rare..............  Tropical to warm    NA--CA/OR/WA stock  NL................  NC
                                   the shelf.                              temperate zones
                                                                           (warmer
                                                                           preference).
Baird's beaked whale (Berardius   Pelagic...........  Primarily along     North Pacific       847 (466)--CA/OR/   NL................  NC
 bairdii).                                             continental slope   Ocean and           WA stock.
                                                       late spring to      adjacent seas.
                                                       early fall.
Cuvier's beaked whale (Ziphius    Pelagic...........  Possible year-      Cosmopolitan......  6,590 (4,481)--CA/  NL................  NC
 cavirostris).                                         round occurrence.                       OR/WA stock.
Blainville's beaked whale         Pelagic...........  Rare, continental   Temperate and       694 (389)--         NL................  NC
 (Mesoplodon densirostris).                            slope region,       tropical waters     Mesoplodon spp.
                                                       generally seaward   worldwide.          CA/OR/WA stock.
                                                       of 500 to 1,000 m
                                                       depth.
Perrin's beaked whale             Pelagic...........  Rare, continental   North Pacific       694 (389)--         NL................  NC
 (Mesoplodon perrini).                                 slope region,       Ocean.              Mesoplodon spp.
                                                       generally seaward                       CA/OR/WA stock.
                                                       of 500 to 1,000 m
                                                       depth.
Lesser beaked whale (Mesoplodon   Pelagic...........  Rare, continental   Temperate and       694 (389)--         NL................  NC
 peruvianis).                                          slope region,       tropical waters     Mesoplodon spp.
                                                       generally seaward   Eastern Pacific     CA/OR/WA stock.
                                                       of 500 to 1,000 m   Ocean.
                                                       depth.
Stejneger's beaked whale          Pelagic...........  Rare, continental   North Pacific       694 (389)--         NL................  NC
 (Mesoplodon stejnegeri).                              slope region,       Ocean.              Mesoplodon spp.
                                                       generally seaward                       CA/OR/WA stock.
                                                       of 500 to 1,000 m
                                                       depth.
Ginkgo-toothed beaked whale       Pelagic...........  Rare, continental   Temperate and       694 (389)--         NL................  NC
 (Mesoplodon ginkgodens).                              slope region,       tropical waters     Mesoplodon spp.
                                                       generally seaward   Indo-Pacific        CA/OR/WA stock.
                                                       of 500 to 1,000 m   Ocean.
                                                       depth.
Hubbs' beaked (Mesoplodon         Pelagic...........  Rare, continental   North Pacific       694 (389)--         NL................  NC
 carlhubbsi).                                          slope region,       Ocean.              Mesoplodon spp.
                                                       generally seaward                       CA/OR/WA stock.
                                                       of 500 to 1,000 m
                                                       depth.
Killer whale (Orcinus orca).....  Pelagic, shelf,     Varies on inter-    Cosmopolitan......  240 (162)--Eastern  NL................  NC
                                   coastal, pack ice.  annual basis,                           North Pacific
                                                       likely in winter                        Offshore stock
                                                       (January to                             346 (346)--
                                                       February).                              Eastern North
                                                                                               Pacific Transient
                                                                                               stock 354 (354)--
                                                                                               West Coast
                                                                                               Transient stock.
False killer whale (Pseudorca     Pelagic...........  Rare..............  Tropical to warm    NA--No stock for    NL................  NC
 crassidens).                                                              temperate zones.    CA/OR/WA.
Short-finned pilot whale          Pelagic, shelf,     Uncommon, more      Warm temperate to   760 (465)--CA/OR/   NL................  NC
 (Globicephala macrorhynchus).     coastal.            common before       tropical waters,    WA stock.
                                                       1982.               ~50[deg] North to
                                                                           40[deg] South.

[[Page 58932]]

 
Bottlenose dolphin (Tursiops      Offshore, inshore,  Offshore stock--    Tropical and        1,006 (684)--CA/OR/ NL................  NC
 truncatus).                       coastal,            Year-round          temperate waters    WA Offshore stock
                                   estuaries.          presence Coastal    between 45[deg]     323 (290)--
                                                       stock--Limited,     North and South.    California
                                                       small population                        Coastal stock.
                                                       within 1 km of
                                                       shore.
Striped dolphin (Stenella         Off continental     Occasional visitor  Tropical to         10,908 (8,231)--CA/ NL................  NC
 coeruleoalba).                    shelf.                                  temperate waters,   OR/WA stock.
                                                                           50[deg] North to
                                                                           40[deg] South.
Short-beaked common dolphin       Shelf, pelagic,     Common, more        Tropical to         411,211 (343,990)-- NL................  NC
 (Delphinus delphis).              seamounts.          abundant in         temperate waters    CA/OR/WA stock.
                                                       summer.             of Atlantic and
                                                                           Pacific Ocean.
Long-beaked common dolphin        Inshore...........  Common, more        Nearshore and       107,016 (76,224)--  NL................  NC
 (Delphinus capensis).                                 inshore             tropical waters.    California stock.
                                                       distribution,
                                                       year-round
                                                       presence.
Pacific white-sided dolphin       Offshore, slope...  Common, year-       Temperate waters    26,930 (21,406)--   NL................  NC
 (Lagenorhynchus obliquidens).                         round, more         of North Pacific    CA/OR/WA,
                                                       abundant November   Ocean.              Northern and
                                                       to April.                               Southern stock.
Northern right whale dolphin      Pelagic...........  Common, more        North Pacific       8,334 (6,019)--CA/  NL................  NC
 (Lissodelphis borealis).                              abundant November   Ocean, 30 to        OR/WA stock.
                                                       to April.           50[deg] North.
Risso's dolphin (Grampus          Deep water,         Common, present in  Continental slope   6,272 (4,913)--CA/  NL................  NC
 griseus).                         seamounts.          summer, more        and outer shelf     OR/WA stock.
                                                       abundant November   of tropical to
                                                       to April.           temperate waters.
Dall's porpoise (Phocoenoides     Shelf, slope,       Common, more        North Pacific       42,000 (32,106)--   NL................  NC
 dalli).                           offshore.           abundant November   Ocean, 30 to        CA/OR/WA stock.
                                                       to April.           62[deg] North.
Harbor porpoise (Phocoena         Coastal and inland  AK to Point         Shallow temperate   NA................  NL................  NC
 phocoena).                        waters.             Conception, CA.     to sub-polar
                                                                           waters of
                                                                           Northern
                                                                           Hemisphere.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Pinnipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion (Zalophus     Coastal, shelf....  Common, Channel     Eastern North       296,750 (153,337)-- NL................  NC
 californianus).                                       Island breeding     Pacific Ocean--     U.S. stock.
                                                       sites in summer.    Alaska to Mexico.
Steller sea lion (Eumetopias      Coastal, shelf....  Rare..............  North Pacific       49,685 (45,916)--   EN--Western stock   D
 jubatus).                                                                 Ocean--Central      Western stock       DL--Eastern stock.
                                                                           California to       58,334 to 72,223
                                                                           Korea.              (52,847)--Eastern
                                                                                               stock.
Pacific harbor seal (Phoca        Coastal...........  Common, haul-outs   Coastal temperate   30,196 (26,667)--   NL................  NC
 vitulina richardii).                                  and rookeries in    to polar regions    California stock.
                                                       Channel Islands,    in Northern
                                                       bulk of stock       Hemisphere.
                                                       north of Point
                                                       Conception.
Northern elephant seal (Mirounga  Coastal, pelagic    Common, haul-outs   Eastern and         124,000 (74,913)--  NL................  NC
 angustirostris).                  when not            and rookeries in    Central North       California
                                   migrating.          Channel Islands,    Pacific Ocean--     breeding stock.
                                                       December to March   Alaska to Mexico.
                                                       and April to
                                                       August, spend 8
                                                       to 10 months at
                                                       sea.
Northern fur seal (Callorhinus    Pelagic, offshore.  Common, small       North Pacific       12,844 (6,722)--    NL................  NC
 ursinus).                                             population breeds   Ocean--Mexico to    California stock.
                                                       on San Miguel       Japan.
                                                       Island May to
                                                       October.
Guadalupe fur seal                Coastal, shelf....  Rare, observed in   California to Baja  7,408 (3,028)--     T.................  D
 (Arctocephalus townsendi).                            Channel Islands.    California,         Mexico to
                                                                           Mexico.             California stock.
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 58933]]

 
                                                                        Fissipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Southern sea otter (Enhydra       Coastal...........  Mainland coastline  North Pacific Rim-- 2,826 (2,723)--     T.................  D
 lutris nereis).                                       from San Mateo      Japan to Mexico.    California stock.
                                                       County to Santa
                                                       Barbara County,
                                                       CA San Nicolas
                                                       Island.
--------------------------------------------------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ NMFS Marine Mammal Stock Assessment Reports.
\2\ U.S. Endangered Species Act: EN = Endangered, T = Threatened, DL = Delisted, and NL = Not listed.
\3\ U.S. Marine Mammal Protection Act: D = Depleted, S = Strategic, and NC = Not Classified.

    Further detailed information regarding the biology, distribution, 
seasonality, life history, and occurrence of these marine mammal 
species in the planned project area can be found in sections 3 and 4 of 
ExxonMobil's IHA application. NMFS has reviewed these data and 
determined them to be the best available scientific information for the 
purposes of the IHA.

Potential Effects of the Specified Activity on Marine Mammals

    This section includes a summary and discussion of the ways that the 
types of stressors associated with the specified activity (e.g., impact 
hammer pipe-driving) have been observed to impact marine mammals. This 
discussion may also include reactions that we consider to rise to the 
level of a take and those that we do not consider to revise to the 
level of take (for example, with acoustics), we may include a 
discussion of studies that showed animals not reacting at all to sound 
or exhibiting barely measureable avoidance). This section is intended 
as a background of potential effects and does not consider either the 
specific manner in which this activity will be carried out or the 
mitigation that will be implemented, and how either of those will shape 
the anticipated impacts from this specific activity. The ``Estimated 
Take by Incidental Harassment'' section later in this document will 
include a quantitative analysis of the number of individuals that are 
expected to be taken by this activity. The ``Negligible Impact 
Analysis'' section will include the analysis of how this specific 
activity will impact marine mammals and will consider the content of 
this section, the ``Estimated Take by Incidental Harassment'' section, 
the ``Mitigation'' section, and the ``Anticipated Effects on Marine 
Mammal Habitat'' section to draw conclusions regarding the likely 
impacts of this activity on the reproductive success or survivorship of 
individuals and from that on the affected marine mammal populations or 
stocks.
    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different frequencies of sound. Based 
on available behavioral data, audiograms have been derived using 
auditory evoked potentials, anatomical modeling, and other data, 
Southall et al. (2007) designate ``functional hearing groups'' for 
marine mammals and estimate the lower and upper frequencies of 
functional hearing of the groups. The functional groups and the 
associated frequencies are indicated below (though animals are less 
sensitive to sounds at the outer edge of their functional range and 
most sensitive to sounds of frequencies within a smaller range 
somewhere in the middle of their functional hearing range):
     Low-frequency cetaceans (13 species of mysticetes): 
functional hearing is estimated to occur between approximately 7 Hz and 
30 kHz;
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): functional hearing is estimated to occur between 
approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia spp., the franciscana (Pontoporia 
blainvillei), and four species of cephalorhynchids): functional hearing 
is estimated to occur between approximately 200 Hz and 180 kHz; and
     Phocid pinnipeds in water: functional hearing is estimated 
to occur between approximately 75 Hz and 100 kHz;
     Otariid pinnipeds in water: functional hearing is 
estimated to occur between approximately 100 Hz and 40 kHz.
    As mentioned previously in this document, 32 marine mammal species 
managed under NMFS jurisdiction (28 cetacean and 4 pinniped species) 
are likely to occur in the action area. Of the 28 cetacean species 
likely to occur in ExxonMobil's action area, 7 are classified as low-
frequency cetaceans (i.e., gray, humpback, minke, Bryde's, sei, fin, 
and blue whale), 19 are classified as mid-frequency cetaceans (i.e., 
sperm, Baird's beaked, Cuvier's beaked, Blainville's beaked, Perrin's 
beaked, Lesser beaked, Stejneger's beaked, Ginkgo-toothed beaked, 
Hubb's beaked, killer, false killer, and short-finned pilot whale, as 
well as bottlenose, striped, short-beaked common, long-beaked common, 
Pacific white-sided, northern right whale, and Risso's dolphin), 2 are 
classified as high-frequency cetaceans (i.e., pygmy sperm whale and 
Dall's porpoise), 2 are classified as phocids (i.e., harbor and 
northern elephant seal), and 2 are classified as otariid pinnipeds 
(i.e., California sea lion and northern fur seal) (Southall et al., 
2007). A species' functional hearing group is a consideration when we 
analyze the effects of exposure to sound on marine mammals.
    Current NMFS practice, regarding exposure of marine mammals to 
high-level underwater sounds is that cetaceans and pinnipeds exposed to 
impulsive sounds at or above 180 and 190 dB (rms), respectively, have 
the potential to be injured (i.e., Level A harassment). NMFS considers 
the potential for Level B (behavioral) harassment to occur when marine 
mammals are exposed to sounds below injury thresholds but at or above 
the 160 dB (rms) threshold for impulse sounds

[[Page 58934]]

(e.g., impact pile-driving) and the 120 dB (rms) threshold for 
continuous noise (e.g., vibratory pile-driving). No vibratory pile-
driving is planned for ExxonMobil's planned activities in the Santa 
Barbara Channel. Current NMFS practice, regarding exposure of marine 
mammals to high-level in-air sounds, as a threshold for potential Level 
B harassment, is at or above 90 dB re 20 [micro]Pa for harbor seals and 
at or above 100 dB re 20 [micro]Pa for all other pinniped species 
(Lawson et al., 2002; Southall et al., 2007). NMFS has not established 
a threshold for Level A harassment for marine mammals exposed to in-air 
noise; however, Southall et al. (2007) recommends 149 dB re 20 
[micro]Pa (peak) (flat) as the potential threshold for injury from in-
air noise for all pinnipeds.
    Acoustic stimuli generated by the conductor pipe installation 
activities, which introduce sound into the marine environment and in-
air, may have the potential to cause Level B harassment of marine 
mammals in the action area. The effects of sounds from impact hammer 
pile-driving activities might include one or more of the following: 
tolerance, masking of natural sounds, behavioral disturbance, temporary 
or permanent hearing impairment, or non-auditory physical or 
physiological effects (Richardson et al., 1995; Gordon et al., 2004; 
Nowacek et al., 2007; Southall et al., 2007). Permanent hearing 
impairment, in the unlikely event that it occurred, will constitute 
injury, but temporary threshold shift (TTS) is not an injury (Southall 
et al., 2007). Although the possibility cannot be entirely excluded, it 
is unlikely that the planned project will result in any cases of 
temporary or permanent hearing impairment, or any significant non-
auditory physical or physiological effects. Based on the available data 
and studies described here, some behavioral disturbance is expected.
    The notice of the proposed IHA (79 FR 36743, June 30, 2014) 
included a discussion of the effects of impact hammer pile-driving on 
mysticetes, odontocetes, and pinnipeds including tolerance, masking, 
behavioral disturbance, hearing impairment, other non-auditory physical 
effects, and airborne sound effects. NMFS refers readers to that 
document, ExxonMobil's IHA application and addendum and NMFS's EA for 
additional information on the behavioral reactions (or lack thereof) by 
all types of marine mammals to pile-driving activities.

Anticipated Effects on Marine Mammal Habitat, Fish, and Invertebrates

    NMFS included a detailed discussion of the potential effects of 
this action on marine mammal habitat, including anticipated effects on 
potential prey and anticipated effects on potential foraging habitat in 
the notice of the proposed IHA (79 FR 36743, June 30, 2014). The 
conductor pipe installation activities will not result in any permanent 
impact on habitats used by the marine mammals in the action area, 
including the food sources they use (i.e., fish and invertebrates), and 
there will be not physical damage to any habitat. While NMFS 
anticipates that the specified activity may result in marine mammals 
avoiding certain areas due to temporary ensonification, this impact to 
habitat is temporary and inconsequential, which was considered in 
further detail in the notice of the proposed IHA (79 FR 36743, June 30, 
2014), as behavioral modification. The main impact associated with the 
activity will be temporarily elevated noise levels and the associated 
direct effects on marine mammals.

Mitigation

    In order to issue an Incidental Take Authorization (ITA) under 
section 101(a)(5)(D) of the MMPA, NMFS must set forth the permissible 
methods of taking pursuant to such activity, and other means of 
effecting the least practicable impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and the availability of such species or 
stock for taking for certain subsistence uses (where relevant).
    ExxonMobil incorporated a suite of appropriate mitigation measures 
into its project description (see Section 11 of the IHA application). 
NMFS re-evaluated these mitigation measures after receiving public 
comments on the notice of the proposed IHA.
    To reduce the potential for disturbance from acoustic stimuli 
associated with the proposed activities, ExxonMobil and/or its 
designees will implement the following mitigation measures for marine 
mammals:
    (1) Buffer and exclusion zones around the sound source;
    (2) Hours of operation;
    (3) Shut-down procedures;
    (4) Ramp-up procedures; and
    Special procedures for situations or species of concern.
    Exclusion Zones--ExxonMobil uses radii to designate exclusion and 
buffer zones and to estimate take for marine mammals. Table 5 (see 
below) shows the distances at which one will expect marine mammal 
exposures to three received sound levels (160, 180, and 190 dB) from 
the impact hammer. The 180 and 190 dB level shut-down criteria are 
applicable to cetaceans and pinnipeds, respectively, as specified by 
NMFS (2000). ExxonMobil used these levels to establish the exclusion 
and buffer zones.

  Table 5--Modeled Maximum Distances To Which In-Water Sound Levels >=190, 180 and 160 dB re 1 [mu]Pa (rms) and In-Air Sound Levels =90 (For
   Harbor Seals) and 100 dB re 20 [mu]Pa (rms) (For All Other Pinnipeds) Could Be Received During the Impact Hammer Pile-Driving Activities (Based on
                                Maximum Hammer Energy of 90 kJ) in the Santa Barbara Channel Off the Coast of California
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Predicted RMS radii distances (m) for in-water    Modeled RMS radii distances (m)
                                                      Water depth                       pile-driving                         for in-air pile-driving
                      Source                              (m)       ------------------------------------------------------------------------------------
                                                                          160 dB           180 dB           90 dB            190 dB           100 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
90 kJ Impact Hammer Pile-Driver...................             366              325               10              3.5   123 (403.5 ft)    41 (134.5 ft)
                                                                       (1,066.3 ft)        (32.8 ft)        (11.5 ft)
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Based on the modeling, exclusion zones (for triggering a shut-down) 
for Level A harassment will be established for cetaceans and pinnipeds 
at 3.5 m (11.5 ft) and 10 m (32.8 ft) from the conductor pipe sound 
source, respectively. These shut-down zones will be monitored by a 
dedicated PSO. If the PSO detects a marine mammal(s) within or about to 
enter the appropriate exclusion zone, the pile-driving activities will 
be shut-down immediately. If marine mammals are present within the 
shut-down zone before impact pile-driving activities begin, start of 
operations will be delayed until the exclusion zones are clear for at 
least 30 minutes. If marine mammals

[[Page 58935]]

appear in the shut-down zone during pile-driving activities, the PSO 
will instruct the hammer operator to halt all operations in a safe, but 
immediate manner. Pile-driving activities will only resume once the 
exclusion zone has been cleared for at least 30 minutes. In the 
unlikely event that the marine mammal enters the exclusion zone during 
pile-driving activities, the exposure and behaviors will be documented 
and reported by the PSO and NMFS will be contacted within 24 hours. A 
non-PSO safety spotter will also be assigned to the lower deck 
observation area. All personnel operating at the lower observation 
levels will be required to wear appropriate personal protective 
equipment.
    Hours of Operation--The planned activities will be conducted on a 
continual 24-hour basis; therefore, some of the 2.5 to 3.3 hours of 
active impact pile-driving periods will be expected to occur during 
non-daylight hours. To facilitate visual monitoring during non-daylight 
hours, the exclusion zones will be illuminated to allow more effective 
viewing by the PSO. Lighting will not be expected to attract marine 
mammals. The areas where the exclusion zones occur fall within the 
jacket structure of the platform, and therefore could be easily 
illuminated by lights and monitored during non-daylight hours. For the 
buffer zone, which will extend out to 325 m (1,066.3 ft) from the 
conductor pipe, PSOs will be stationed on an upper deck of the Harmony 
Platform to monitor for marine mammals during the pile-driving 
activities. During non-daylight hours, PSOs will utilize night-vision 
devices and other appropriate equipment to monitor marine mammals. If 
nighttime visual aids are insufficient, ExxonMobil plans to use daytime 
visual counts of marine mammals as an estimate of the number of marine 
mammals present during non-daylight hours (within a 24-hour period), 
noting that diurnal activities for most marine mammals are expected to 
vary somewhat.
    Shut-down Procedures--ExxonMobil will shut-down the operating 
hammer if a marine mammal is detected outside the exclusion zone, and 
the sound source will be shut-down before the animal is within the 
exclusion zone. Likewise, if a marine mammal is already within the 
exclusion zone when first detected, the sound source will be shut-down 
immediately.
    Following a shut-down, ExxonMobil will not resume pile-driving 
activities until the marine mammal has cleared the exclusion zone. 
ExxonMobil will consider the animal to have cleared the exclusion zone 
if:
     A PSO has visually observed the animal leave the exclusion 
zone, or
     A PSO has not sighted the animal within the exclusion zone 
for 15 minutes for species with shorter dive durations (i.e., small 
odontocetes and pinnipeds), or 30 minutes for species with longer dive 
durations (i.e., mysticetes and large odontocetes, including sperm, 
pygmy and dwarf sperm, killer, and beaked whales).
    All visual monitoring will be conducted by qualified PSOs. Visual 
monitoring will be conducted continuously during active pile-driving 
activities. PSOs will not have any tasks other than visual monitoring 
and will conduct monitoring from the best vantage point(s) practicable 
(e.g., on the Harmony Platform or other suitable location) that 
provides 360[deg] visibility of the Level A harassment exclusion zones 
and Level B harassment buffer zone, as far as possible. The PSO will be 
in radio communication with the hammer operator during pile-driving 
activities, and will call for a shut-down in the event a pinniped or 
cetacean appears to be headed toward its respective exclusion zone for 
cetaceans and pinnipeds.
    Ramp-up Procedures--Ramp-up (sometimes referred to as a ``soft-
start'') of the impact hammer provides a gradual increase in sound 
levels until the full sound level is achieved. The purpose of a ramp-up 
is to ``warn'' marine mammals in the vicinity of the impact hammer and 
to provide the time for them to leave the area avoiding any potential 
injury or impairment of their hearing abilities. A ramp-up consists of 
an initial set of three strikes from the impact hammer at 40% energy, 
followed by a 30-second waiting period, then two subsequent three 
strike sets.
    The buffer zone will be monitored by PSOs beginning 30 minutes 
before pile-driving activities, during pile-driving, and for 30 minutes 
after pile-driving stops. During ramp-up, the PSOs will monitor the 
exclusion zone, and if marine mammals are sighted, a shut-down will be 
implemented.
    If the complete exclusion zone has not been visible for at least 30 
minutes prior to the start of operations in either daylight or 
nighttime, ExxonMobil will not commence the ramp-up. ExxonMobil will 
not initiate a ramp-up of the impact hammer if a marine mammal is 
sighted within or near the applicable exclusion zones during the day or 
close to the Harmony Platform at night.
    Special Procedures for Situations of Species of Concern--It is 
unlikely that a North Pacific right whale will be encountered during 
the conductor pipe installation activities, but if so, the pipe-driving 
activities will be shut-down immediately if one is visually sighted at 
any distance from the Harmony Platform because of its rarity and 
conservation status. The pipe-driving activities shall not resume (with 
ramp-up) until 30 minutes after the last documented North Pacific right 
whale visual sighting. Concentrations of humpback, sei, fin, blue and/
or sperm whales shall be avoided if possible (i.e., exposing 
concentrations of animals to 160 dB), and the sound source shall be 
shut-down if necessary. For purposes of this planned conductor pipe 
installation activities, a concentration or group of whales will 
consist of three or more individuals visually sighted that do not 
appear to be traveling (e.g., feeding, socializing, etc.).
    Oil Spill Plan--ExxonMobil has developed an Oil Spill Response Plan 
and it is on file with BOEM.

Mitigation Conclusions

    NMFS has carefully evaluated the applicant's mitigation measures 
and has considered a range of other measures in the context of ensuring 
that NMFS prescribes the means of effecting the least practicable 
impact on the affected marine mammal species and stocks and their 
habitat. NMFS's evaluation of potential measures included consideration 
of the following factors in relation to one another:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure is expected to minimize adverse impacts 
to marine mammals;
    (2) The proven or likely efficacy of the specific measure to 
minimize adverse impacts as planned; and
    (3) The practicability of the measure for applicant implementation, 
including consideration of personnel safety, practicality of 
implementation, and impact on the effectiveness of the activity.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    (1) Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    (2) A reduction in the numbers of marine mammals (total number or 
number at biologically important time or location) exposed to received 
levels of hammer pile-driving, or other activities expected to result 
in the take of marine mammals (this goal may

[[Page 58936]]

contribute to 1, above, or to reducing harassment takes only).
    (3) A reduction in the number of times (total number or number at 
biologically important time or location) individuals will be exposed to 
received levels of hammer pile-driving, or other activities expected to 
result in the take of marine mammals (this goal may contribute to 1, 
above, or to reducing harassment takes only).
    (4) A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to received 
levels of hammer pile-driving, or other activities expected to result 
in the take of marine mammals (this goal may contribute to a, above, or 
to reducing the severity of harassment takes only).
    (5) Avoidance of minimization of adverse effects to marine mammal 
habitat, paying special attention to the food base, activities that 
block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
    (6) For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on NMFS's evaluation of the applicant's measures, as well as 
other measures considered by NMFS or recommended by the public, NMFS 
has determined that the mitigation measures provide the means of 
effecting the least practicable impact on marine mammal species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Monitoring and Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for ITAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present in the action area. ExxonMobil 
submitted a marine mammal monitoring plan as part of the IHA 
application. It can be found in Section 13 of the IHA application. The 
plan may be modified or supplemented based on comments or new 
information received from the public during the public comment period.
    Monitoring measures prescribed by NMFS should accomplish one or 
more of the following general goals:
    (1) An increase in the probability of detecting marine mammals, 
both within the mitigation zone (thus allowing for more effective 
implementation of the mitigation) and in general to generate more data 
to contribute to the analyses mentioned below;
    (2) An increase in our understanding of how many marine mammals are 
likely to be exposed to levels of sound from impact hammer pile-driving 
activities that we associate with specific adverse effects, such as 
behavioral harassment, TTS or PTS;
    (3) An increase in our understanding of how marine mammals respond 
to stimuli expected to result in take and how anticipated adverse 
effects on individuals (in different ways and to varying degrees) may 
impact the population, species, or stock (specifically through effects 
on annual rates of recruitment or survival) through any of the 
following methods:
     Behavioral observations in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information);
     Physiological measurements in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict receive level, distance from the source, and other 
pertinent information);
     Distribution and/or abundance comparisons in times or 
areas with concentrated stimuli versus times or areas without stimuli;
    (4) An increased knowledge of the affected species; and
    (5) An increase in our understanding of the effectiveness of 
certain mitigation and monitoring measures.

Monitoring

    ExxonMobil will conduct to sponsor marine mammal monitoring during 
the conductor pipe installation activities, in order to implement the 
mitigation measures that require real-time monitoring, and to satisfy 
the anticipated monitoring requirements of the IHA. ExxonMobil's 
``Monitoring Plan'' is described below this section. ExxonMobil 
understand that this monitoring plan will be subject to review by NMFS 
and that refinements may be required. Two main types of monitoring will 
be performed for this planned project: (1) In-situ measurement of sound 
pressure levels; and (2) visual observations of the number and type of 
marine mammals that enter sound exposure zones. In-situ acoustic data 
will be used to validate model predictions of sound pressure levels 
near and with distance from the conductor pipe sound source, including 
the predicted maximum distances for the buffer and exclusion zones. If 
measured results differ from modeled results, measured data will be 
used to revise buffer and exclusion zone boundaries to reflect actual 
conditions during planned project activities. Data from visual 
monitoring will be used to validate take estimate calculations.

Acoustic Monitoring

    Acoustic monitoring using hydrophones and microphones will be 
conducted to obtain and validate modeled in-water and in-air sound 
levels during the pipe-driving activities. Each hydrophone (in-water) 
and microphone (in-air) will be calibrated following the manufacturer's 
recommendations prior to the start of the planned project and checked 
for accuracy and precision at the end of the data collection for each 
conductor pipe or as practical during conductor pipe installation 
activities. Environmental data will be collected to supplement the 
acoustic monitoring and include: wind speed and direction, air 
temperature, humidity, near-surface water temperature, weather 
conditions, and other appropriate factors that could contribute to 
influencing either in-air or in-water sound transmission levels. Prior 
to deploying monitoring equipment, the acoustics specialist will be 
provided with the hammer model and size, hammer energy settings, and 
projected blows per minute for the conductor pipe segments requiring 
hammer pipe-driving. Background in-air and in-water sound levels will 
be measured at Harmony Platform in the absence of pipe-driving 
activities to obtain an ambient noise level, and recorded over a 
frequency range of 10 Hz to 20 kHz. Ambient noise level measurements 
will be conducted before, during, and after the project. The measured 
in-air and in-water sound data will be used to recalibrate and refine 
the sound propagation model used to determine the buffer and exclusion 
zones. Also, sound pressure levels associated with ramp-up techniques 
will be measured.
    In-Water Monitoring--Acoustic monitoring will be performed at a 
minimum of two fixed stations located at 14 to 30 m (45.9 to 98.4 ft) 
and approximately 325 to 500 m (+/-33 m 10%, 1,066.3 to 1,640.4 ft) 
depending on the conductor pipe sound source location to the monitoring 
location.

[[Page 58937]]

These distances represent the 180 dB and 160 dB (rms) modeled sound 
levels. The following general approach will be used to measure in-water 
sound levels:
     Acoustic monitoring will be conducted over the entire 
conductor pipe installation period for each conductor pipe, starting 
approximately 1 hour prior to conductor pipe installation through 1 
hour after impact hammering has stopped. Pre- and post-hammer conductor 
pipe installation data will be used to determine ambient/background 
noise levels.
     A stationary hydrophone system with the ability to measure 
and record sound pressure levels will be deployed at a minimum of two 
monitoring locations (stations). SPLs will be recorded in voltage, 
converted to microPascals ([micro]Pa), and post-processed to decibels 
(dB [re 1 [micro]Pa]). For the first conductor pipe installation, 
hydrophones are placed at 14 to 30 m (+/-1 m) and at 325 to 500 (+/-33 
m) depending on the conductor pipe sound source location to the 
monitoring location at depths ranging from 10 to 30 m (32.8 to 98.4 ft) 
below the water surface to avoid potential inferences for surface water 
energy, and to target the depth range of maximum occurrence of marine 
mammals most likely in the area during the operations. The equipment 
will obtain data for the most likely depth range of marine mammal 
occurrence. Horizontal displacement of +/-10% may be expected for 
instrument movement due to the water depth and forces from tides, 
currents, and storms. Additional hydrophone mooring systems may be 
deployed at additional distances and/or depths. Following each 
successive conductor pipe installation, the water depth and 
geographical orientation of the hydrophone may be changed to validate 
modeled SPLs at varying water depths and direction.
     At a minimum, the following sound data will be analyzed 
(post-processed) from recorded sound levels: Absolute peak overpressure 
and under pressure levels for each conductor pipe; average, minimum, 
and maximum sound pressure levels (rms), integrated from 3 Hz to 20 
kHz; average duration of each hammer strike (blow), and total number of 
strikes per continuous impact hammer conductor pipe installation period 
for each conductor.
    In the event that field measurements indicate different sound 
pressure levels (rms) values than those predicted by modeling for 
either the maximum distances of the buffer or exclusion zones from the 
conductor sound source, corresponding boundaries for the buffer and 
appropriate exclusion zones will be increased/decreased accordingly, 
following NMFS notification, concurrence, and authorization.
    In-Air Monitoring--Reference measurements will be made at 
approximately 10 to 20 m (32.8 to 65.6 ft) from the initial hammer 
strike position using a stationary microphone. The microphone will be 
placed as far away from other large sound sources as practical. The in-
air buffer zone predicted for pinnipeds (non-harbor seal, 100 dB re 20 
[micro]Pa) was estimated at 41 m (134.5 ft) from the hammer impact 
point on the conductor pipe. In-air sound levels will be recorded at 
several points around the base of the Harmony Platform at sea level to 
validate modeled sound levels. Distances closer to the sound source may 
be monitored for model validation purposes, but only if safety issues 
are not introduced. Recorded data will be recorded as dB (re 20 
[micro]Pa, A-weighted and unweighted) for comparison to in-air noise 
thresholds for Level B harassment for pinnipeds.
    Sound Source Verification--At the initiation of conductor pipe 
installation activities using the impact hammer (i.e., the installation 
of the first pipe), direct measurements will be taken in the near and 
far field of the received levels of underwater and in-air sound versus 
distance and direction from the sound source using calibrated 
hydrophones. The acoustic data from the sound source verification will 
be analyzed as quickly as reasonably practicable in the field and used 
to verify and adjust (based on the predicted distances) the buffer and 
exclusion zones distances. The field report will be made available to 
NMFS for review and approval and PSOs after completing the measurements 
and before beginning the installation of the remaining conductor pipes.

Platform-Based Visual Monitoring

    ExxonMobil's PSOs will be based aboard the Harmony Platform and 
will watch for marine mammals near the platform during conductor pipe 
installation activities during daytime and nighttime pipe-driving 
activities. Visual monitoring for marine mammals will be performed at a 
minimum during periods of active hammer pipe-driving throughout the 
planned project following general procedures in Baker et al. (2013). 
Monitoring by PSOs will begin at least 30 minutes before the start of 
impact hammer pipe-driving, continue through an estimated 2.5 to 3.3 
hours of pipe-driving, and conclude 30 minutes after pipe-driving stops 
(up to 4.3 hours of monitoring per a period of pipe-driving). Five to 7 
periods of impact hammer pipe-driving will be required for each 
conductor pipe. When feasible, PSOs will conduct observations during 
periods when the impact hammer pipe-driving is not operating for 
comparison of sighting rates and behavior with and without operations 
and between pipe-driving periods. In addition to monitoring during 
pipe-driving activities, baseline monitoring of marine mammals will be 
performed up to one week before and one week after conductor pipe 
installation, as well as selected periods in between impact hammer 
pipe-driving activities.
    The exclusion zone will be monitored to prevent injury to marine 
mammal species. Based on PSO observations, the impact hammer pipe-
driving will be shut-down when marine mammals are observed within or 
about to enter the designated exclusion zone. The exclusion zone is a 
region in which a possibility exists of adverse effects on animal 
hearing or physical effects. A comprehensive monitoring plan will be 
developed to ensure compliance with the IHA for this project.
    Methods--There will be a team of 3 PSOs based aboard Harmony 
Platform conducting monitoring during active hammer pipe-driving 
periods. Visual observations will take place during active hammering 
periods which includes both daylight and nighttime operations. This 
monitoring will occur for approximately 4.3 hours (3.3 hour monitoring 
plus 0.5 hour pre- and post-hammering) during a single hammering phase 
followed by approximately 6.3 hours of off-duty rest. A total of 5 to 7 
observation periods corresponding to the driving of the pipe segments 
will be anticipated for each of the six conductors. It is possible that 
an impact hammer pipe-driving session will take less than 3.3 hours and 
that the ``rest interval'' for the visual monitors separating driving 
segments will be less than 6.3 hours. If driving and rest intervals are 
reduced and additional segments are added (e.g., seven instead of 
five), two alternating teams of three PSOs may be required. At the 
conclusion of impact hammer pipe-driving activities for a single 
conductor pipe, PSOs may be transferred to shore to await the next 
active pipe-driving phase.
    PSOs will be placed at the best practicable vantage point(s) (e.g., 
lower platform level, upper platform level) to monitor the applicable 
buffer and exclusion zones for marine mammals. The PSOs will have 
authority to implement shut-down/delay ramp-up procedures, if 
applicable, by calling the hammer operator for a shut-down via radio 
communication. For the buffer zone, two PSOs will be stationed on an

[[Page 58938]]

upper platform deck where they have a clear view of the monitoring 
area. They will be approximately 180 degrees apart and each will 
monitor approximately one-half of the corresponding buffer zone and 
beyond with binoculars and other appropriate equipment. For exclusion 
zone area, one PSO will concurrently monitor the applicable radii for 
pinnipeds and cetaceans, respectively, from a lower level observation 
post that provides a clear view of the sea surface around the actively 
driven conductor pipe. The lower observation area will be illuminated 
during nighttime observations. Visual aids may be used but will not be 
required, providing the PSO has a clear view of the sea surface with 
the naked eye. A non-PSO safety spotter will also be assigned to the 
lower deck observation area. The safety spotter will be available to 
deter errant California sea lions using NMFS-recommended methods (see 
below) (NMFS, 2008).
    All personnel operating on the Harmony Platform will be required to 
receive required training and wear appropriate personal protective 
equipment. Personal protective equipment is specific to the task, 
location, and environmental conditions (e.g., weather, operations 
risks). It includes items such as floatation vests, hard hats, steel-
toed shoes, gloves, fire-resistant clothing, gear, eye protection, and 
other protective equipment. Details on specific personal protective 
equipment items required for PSO and acoustic monitoring will be 
determined via the regular work risk assessment process, and will be 
presented in the associated monitoring plans for the project.
    Equipment for monitoring will include hearing protection from where 
observations are made from high noise areas of the platform, marine 
radios with headsets, time keeping device (e.g., watch or cell phone), 
day and night range finding binoculars (7 x 50 or greater), notebooks 
with standardized recording forms, species identification guides, and a 
project-specific monitoring plan approved by NMFS (to be submitted 
separately).
    PSO Qualifications--Monitoring will be conducted by qualified PSOs 
defined in Baker et al. (2013) and approved by NMFS. PSOs dedicated to 
the planned project will have no other activity-related tasks.

PSO Data and Documentation

    PSOs will record data to estimate the numbers of marine mammals 
exposed to various received sound levels and to document apparent 
disturbance reactions or lack thereof. Data will be used to estimate 
numbers of animals potentially ``taken'' by harassment (as defined in 
the MMPA). They will also provide information needed to order a shut-
down of the impact hammer when a marine mammal is within or near the 
exclusion zone. Visual observations will also be made during pipe-
driving activities as well as daytime periods from the Harmony Platform 
when the regular operations will be underway without pipe-driving 
activities to collect baseline biological data.
    When a sighting is made, the following information about the 
sighting will be recorded:
    1. Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from platform, sighting cue, apparent 
reaction to the sound source (e.g., none, avoidance, approach, 
paralleling, etc., and including responses to ramp-up), speed of 
travel, and duration of presence.
    2. Date, time, location, heading, speed, activity of the conductor 
pipe installation activities, weather conditions, Beaufort sea state 
and wind force, visibility, and sun glare.
    The data listed under (2) will also be recorded at the start and 
end of each observation watch, and during a watch whenever there is a 
change in one or more of the variables.
    All observations, as well as information regarding ramp-ups or 
shut-downs will be recorded in a standardized format.
    Results from the platform-based visual observations will provide 
the following information:
    1. The basis for real-time mitigation (impact hammer shut-down).
    2. Information needed to estimate the number of marine mammals 
potentially taken by harassment, which must be reported to NMFS.
    3. Data on the occurrence, distribution, and activities of marine 
mammals in the area where the conductor pipe installation activities 
are conducted.
    4. Information to compare the distance and distribution of marine 
mammals relative to the source platform at times with and without pipe-
driving activities.
    5. Data on the behavior and movement patterns of marine mammals 
seen at times with and without pipe-driving activities.

Reporting

    ExxonMobil will submit a comprehensive report to NMFS within 90 
days after the end of the conductor pipe installation activities and 
the expiration of the IHA (if issued). The report would describe the 
pipe-driving activities that were conducted and sightings of marine 
mammals near the operations. The report submitted to NMFS will provide 
full documentation of methods, results, and interpretation pertaining 
to all monitoring. The 90-day report will summarize the dates and 
location of impact hammer pipe-driving activities and all marine mammal 
sightings (i.e., dates, times, locations, activities, and associated 
seismic survey activities). The report will minimally include:
     Summaries of monitoring effort--total hours, total 
distances, and distribution of marine mammals through the activity 
period accounting for Beaufort sea state and other factors affecting 
visibility and detectability of marine mammals;
     Analyses of the effects of various factors influencing 
detectability of marine mammals including Beaufort sea state, number of 
PSOs, and fog/glare;
     Species composition, occurrence, and distribution of 
marine mammals sightings including date, water depth, numbers, age/
size/gender, and group sizes; and analyses of the effects of 
activities;
     Sighting rates of marine mammals during periods with and 
without impact hammer pipe-driving activities (and other variables that 
could affect detectability);
     Initial sighting distances versus operational activity 
state;
     Closest point of approach versus operational activity 
state;
     Observed behaviors and types of movements versus 
operational activity state;
     Numbers of sightings/individuals seen versus operational 
activity state; and
     Distribution around the platform versus operational 
activity state.

The report will also include estimates of the number and nature of 
exposures that could result in ``takes'' of marine mammals by 
harassment or in other ways (based on presence in the buffer and/or 
exclusion zones). After the report is considered final, it will be 
publicly available on the NMFS Web site at: http://www.nmfs.noaa.gov/pr/permits/incidental/.

    Reporting Prohibited Take--In the unanticipated event that the 
specified activity clearly causes the take of a marine mammal in a 
manner prohibited by this IHA, such as an injury (Level A harassment), 
serious injury, or mortality (e.g., ship-strike, gear interaction, and/
or entanglement), ExxonMobil will

[[Page 58939]]

immediately cease the specified activities and immediately report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS at 301-427-8401 and/or by email to 
[email protected] and [email protected] and the West 
Coast Regional Stranding Coordinator (562-980-3230). The report must 
include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Type of activity involved;
     Description of the circumstances during and leading up to 
the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with ExxonMobil 
to determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. ExxonMobil may not resume 
their activities until notified by NMFS via letter or email, or 
telephone.
    Reporting an Injured or Dead Marine Mammal with an Unknown Cause of 
Death--In the event that ExxonMobil discovers an injured or dead marine 
mammal, and the lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition as described in the next paragraph), 
ExxonMobil will immediately report the incident to the Chief of the 
Permits and Conservation Division, Office of Protected Resources, NMFS, 
at 301-427-8401, and/or by email to [email protected] and 
[email protected], and the NMFS West Coast Regional Office (1-
866-767-6114) and/or to the West Coast Regional Stranding Coordinator 
(562-980-3230). The report must include the same information identified 
in the paragraph above. Activities may continue while NMFS reviews the 
circumstances of the incident. NMFS will work with ExxonMobil to 
determine whether modifications to the activities are appropriate.
    Reporting an Injured or Dead Marine Mammal Not Related to the 
Activities--In the event that ExxonMobil discovers an injured or dead 
marine mammal, and the lead PSO determines that the injury or death is 
not associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate or advanced 
decomposition, or scavenger damage), ExxonMobil will report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, at 301-427-8401, and/or by email to 
[email protected] and [email protected], and the NMFS 
West coast Regional Office (1-866-767-6114) and/or to the West Coast 
Regional Stranding Coordinator (562-980-3230), within 24 hours of 
discovery. ExxonMobil will provide photographs or video footage (if 
available) or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network. Activities may continue 
while NMFS reviews the circumstances of the incident.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

Table 6--NMFS's Current Underwater and In-Air Acoustic Exposure Criteria
------------------------------------------------------------------------
                                       Criterion
            Criterion                 definition           Threshold
------------------------------------------------------------------------
                     Impulsive (Non-Explosive) Sound
------------------------------------------------------------------------
Level A harassment (injury).....  Permanent           180 dB re 1 [mu]Pa-
                                   threshold shift     m (root means
                                   (PTS) (Any level    square [rms])
                                   above that which    (cetaceans).
                                   is known to cause  190 dB re 1 [mu]Pa-
                                   TTS).               m (rms)
                                                       (pinnipeds).
Level B harassment..............  Behavioral          160 dB re 1 [mu]Pa-
                                   disruption (for     m (rms).
                                   impulsive noise).
Level B harassment..............  Behavioral          120 dB re 1 [mu]Pa-
                                   disruption (for     m (rms).
                                   continuous noise).
------------------------------------------------------------------------
                              In-Air Sound
------------------------------------------------------------------------
Level A harassment..............  NA................  NA.
Level B harassment..............  Behavioral          90 dB re 20 [mu]Pa
                                   disruption.         (harbor seals).
                                                      100 dB re 20
                                                       [mu]Pa (all other
                                                       pinniped
                                                       species).
                                                      NA (cetaceans).
------------------------------------------------------------------------

    Level B harassment is anticipated and authorized as a result of the 
conductor pipe installation activities at the Harmony Platform in the 
Santa Barbara Channel offshore of California. Acoustic stimuli (i.e., 
increased underwater and in-air sound) generated during the pipe-
driving activities are expected to result in the behavioral disturbance 
of some marine mammals. There is no evidence that the planned 
activities could result in injury, serious injury, or mortality for 
which ExxonMobil seeks the IHA. The required mitigation and monitoring 
measures will minimize any potential risk for injury, serious injury, 
or mortality.

[[Page 58940]]

    The following sections describe ExxonMobil and NMFS's methods to 
estimate take by incidental harassment and present the total take 
authorized incidental to the conductor pipe installation activities at 
the Harmony Platform in the Santa Barbara Channel offshore of 
California. The estimated takes were calculated using information on 
sound source levels, sound propagation, maximum distances from the 
sound source to Level A and Level B harassment exposure thresholds, and 
estimated density of marine mammals in the action area. Take estimates 
were calculated for in-water (cetaceans and pinnipeds) and in-air 
(pinnipeds only). The estimates are based on the following information:
     Thresholds for marine mammals to in-water and in-air 
noise;
     Sound levels at the conductor pipe from hammer strike;
     Sound propagation (transmission/spreading loss) through 
the environment (i.e., air, water);
     Maximum distances from the sound sources to the 
corresponding impact zones (based on Level A and Level B harassment 
thresholds) for marine mammals;
     Density estimate for each species of marine mammals 
(calculated as stock abundance divided by 12,592 km\2\ [3,671.2 
nmi\2\]area [except where noted]); and
     Number of takes for each species of marine mammals within 
a group (calculated as density multiplied by buffer/exclusion zone 
multiplied by days of activity).
    Sound levels for impulsive (impact) pipe-driving by the hammer and 
propagation through water and in-air at the Harmony Platform were 
modeled by JASCO Applied Sciences, Ltd. The modeling results are 
presented in JASCO's acoustic modeling report as an addendum to the IHA 
application titled ``Assessment of Airborne and Underwater Noise from 
Pile Driving Activities at the Harmony Platform.'' Methods used to 
estimate marine mammal densities and takes for the action area in the 
Santa Barbara Channel are presented in Sections 6.1.5 and 6.1.6 of the 
IHA application for likely exposures to species of marine mammals.
    Densities of marine mammal species likely to occur in the action 
area of the Santa Barbara Channel were taken directly from scientific 
literature or calculated using corresponding abundances in NMFS Stock 
Assessment Reports. Density estimates for sperm and Baird's beaked 
whale, and short-beaked common, Pacific white-sided, Risso's, and 
northern right whale dolphin, and Dall's porpoise were determined using 
the Strategic Environmental and Development Program (SERDP)/National 
Aeronautics and Space Administration (NASA)/NOAA Marine Animal Mapper 
and OBIS-SEAMAP database using NMFS Southwest Fisheries Science Center 
(SWFSC) summer densities for the California Current ecosystem. Density 
estimates for the blue, fin, and humpback whale were taken directly 
from Redfern et al. (2013), using the upper limit reported for the 
density contour that includes the Harmony Platform. Redfern et al. 
(2013) estimated densities for these three species using NMFS sightings 
collected from primarily August through November over a period from 
1991 to 2009 throughout the Santa Barbara Channel. Results for blue, 
fin, and humpback whales are presented in Figures 6-3, 6-4, and 6-5 of 
the IHA application. These densities are considered more accurate than 
those based on reported stock abundances because even though they are 
for the same monthly period and geographical location, they include a 
correction factor to correct for non-observational periods. For 
calculated densities of likely affected marine mammal species, stock 
abundances, which generally range from the state of Washington to 
northern Baja California, Mexico, were assumed to be concentrated 
within the 12,593 km\2\ (3,671.5 nmi\2\) action area in the Santa 
Barbara Channel. The action area includes the Harmony Platform, and 
extends 18 km (9.7 nmi) to the north, 60 km (32.4 nmi) to the west, and 
70 km (37.8 nmi) to the south of Point Conception, California. The 
eastern boundary is 35 km (18.9 nmi) east of Anacapa Island. Use of 
this area produces a conservative density estimate because the 
geographical range of each marine mammal species evaluated is much 
greater than 70 km (nmi) of the coastline selected to represent the 
action area, including season-specific ranges for species that migrate 
(e.g., gray whale). For marine mammal species potentially exposed to 
in-air noise, pinniped densities were calculated by dividing the stock 
abundance for each marine mammal species by the 1,130 m\2\ (12,163.2 
ft\2\) impact area of the Harmony Platform near sea level where the 
animals could potentially haul-out and/or have their heads out of the 
water. Tables 6-7 and 6-8 of the IHA application describe the 
calculated densities and estimated take by marine mammal species as 
well as associated data for the in-water and in-air sound thresholds, 
respectively. Although there is some uncertainty about the 
representativeness of the data and the assumptions used in the 
calculations below, the approach used here is believed to be the best 
available approach.

    Table 7--Estimated Densities and Possible Number of Marine Mammal Species That Might Be Exposed to Greater Than or Equal to 160 dB (Pipe-Driving
               Activities) During Exxonmobil's Conductor Pipe Installation Activities in the Santa Barbara Channel Offshore of California
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Calculated take
                                                                  from pipe-driving
                                                                  activities in-air
                                                Calculated take    (i.e., estimated
                                               from pipe-driving      number of                                         Approximate
                                   Density in    activities in-      individuals                                       percentage of
                                  action area     water (i.e.,     exposed to sound     Total                           population/    Population trend
             Species              (#/   estimated number  levels >=90 dB re   authorized     Abundance \7\    stock estimate          \7\
                                   km\2\)\1\     of individuals     20 [mu]Pa for      Take \6\                            (for
                                                exposed to sound   harbor seals and                                     authorized
                                                levels >=160 dB      90 dB re 20                                         take) \8\
                                                re 1 [mu]Pa) \4\    [mu]Pa for all
                                                                   other pinnipeds)
                                                                         \5\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Mysticetes
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Pacific right whale.......           NA                  0                  0            0  NA (26)--Eastern                NA  NA.
                                                                                                   North Pacific
                                                                                                   stock.

[[Page 58941]]

 
Eastern North Pacific Gray whale       1.5188              3.063                  0           10  19,126 (18,107)--             0.05  Increasing over
                                                                                                   Eastern North                       past several
                                                                                                   Pacific stock 155                   decades--Eastern
                                                                                                   (142)--Western                      North Pacific
                                                                                                   North Pacific                       stock.
                                                                                                   population.
Humpback whale..................   \3\ 0.0055             0.0332                  0            2  1,918 (1,855)--CA/             0.1  Increasing.
                                                                                                   OR/WA stock.
Minke whale.....................         0.04             0.2418                  0            2  478 (202)--CA/OR/             0.42  NA.
                                                                                                   WA stock.
Bryde's whale...................           NA                  0                  0            2  NA................              NA  NA.
Sei whale.......................         0.01             0.0605                  0            2  126 (83)--Eastern             1.58  NA.
                                                                                                   North Pacific
                                                                                                   stock.
Fin whale.......................   \3\ 0.0065             0.0392                  0            2  3,051 (2,598)--CA/            0.07  Increasing.
                                                                                                   OR/WA stock.
Blue whale......................    \2\ 0.006            0.00362                  0            2  1,647 (1,551)--               0.12  NA.
                                                                                                   Eastern North
                                                                                                   Pacific stock.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Odontocetes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale.....................          \2\           0.000327                  0            2  971 (751)--CA/OR/             0.21  NA.
                                    0.0000542                                                      WA stock.
Pygmy sperm whale...............         0.05              0.302                  0            1  579 (271)--CA/OR/             0.17  NA.
                                                                                                   WA stock.
Dwarf sperm whale...............           NA                  0                  0            0  NA--CA/OR/WA stock              NA  NA.
Baird's beaked whale............          \2\             0.0074                  0            6  847 (466)--CA/OR/             0.71  NA.
                                     0.001224                                                      WA stock.
Cuvier's beaked whale...........       0.5233             3.1633                  0            4  6,590 (4,481)--CA/            0.06  Declining off CA/
                                                                                                   OR/WA stock.                        OR/WA.
Mesoplodon beaked whale.........       0.0551             0.3331                  0            2  694 (389)--CA/OR/             0.29  Declining off CA/
                                                                                                   WA stock.                           OR/WA.
Killer whale....................      0.07464             0.4512                  0           10  240 (162)--Eastern  4.17/2.89/2.82  NA--Eastern North
                                                                                                   North Pacific                       Pacific Offshore
                                                                                                   stock 346 (346)--                   stock; NA--
                                                                                                   Eastern North                       Eastern North
                                                                                                   Pacific Transient                   Pacific Transient
                                                                                                   stock 354 (354)--                   stock;
                                                                                                   West Coast                          Increasing--West
                                                                                                   Transient stock.                    Coast Transient
                                                                                                                                       stock.
False killer whale..............           NA                  0                  0           50  NA................              NA  NA.
Short-finned pilot whale........         0.06             0.3627                  0           40  760 (465)--CA/OR/             5.26  NA.
                                                                                                   WA stock.
Bottlenose dolphin..............       0.0799             0.4829                  0           10  1,006 (684)--CA/OR/           0.99  NA--CA/OR/WA
                                                                                                   WA stock.                           Offshore stock;
                                                                                                                                       NA--CA Coastal
                                                                                                                                       stock.
Striped dolphin.................          \2\             0.0164                  0           20  10,908 (8,231)--CA/           0.18  NA.
                                     0.002711                                                      OR/WA stock.
Short-beaked common dolphin.....          \2\             5.7186                  0          450  411,211 (343,990)--           0.11  Varies with
                                     0.946007                                                      CA/OR/WA stock.                     oceanographic
                                                                                                                                       conditions.
Long-beaked common dolphin......          8.5            51.3825                  0          120  107,016 (76,224)--            0.11  Increasing over
                                                                                                   CA stock.                           last 30 years.
Pacific white-sided dolphin.....          \2\             0.4149                  0           30  26,930 (21,406)--             0.11  NA.
                                     0.068630                                                      CA/OR/WA stock.
Northern right whale dolphin....  \2\ 0043996             0.2659                  0          100  8,334 (6,019)--CA/            1.19  NA.
                                                                                                   OR/WA stock.
Risso's dolphin.................          \2\             0.3223                  0           10  6,272 (4,913)--CA/            0.16  NA.
                                     0.053323                                                      OR/WA stock.
Dall's porpoise.................     0.028931             0.1749                  0           50  42,000 (32,106)--             0.12  NA.
                                                                                                   CA/OR/WA stock.
Harbor porpoise.................            0                  0                  0            0  NA................              NA  NA.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Pinnipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion.............         23.6            142.662             17.997   143 + 18 =  296,750 (153,337)--           0.05  Increasing.
                                                                                             161   U.S. stock.
Steller sea lion................           NA                  0                  0            0  49,685 (42,366)--               NA  Declining--Western
                                                                                                   Western stock                       stock;
                                                                                                   58,334 (72,223)--                   Increasing--Easte
                                                                                                   Eastern stock.                      rn stock;
                                                                                                                                       Declining in CA.
Pacific harbor seal.............          2.4             14.508              5.491  15 + 6 = 21  30,196 (26,667)--             0.07  Increased 1981 to
                                                                                                   CA stock.                           2004.

[[Page 58942]]

 
Northern elephant seal..........         9.85            59.5433              7.512  60 + 8 = 68  124,000 (74,913)--            0.05  Increasing through
                                                                                                   CA breeding stock.                  2005.
Northern fur seal...............         0.79             4.7756              0.602    5 + 1 = 6  12,844 (6,722)--              0.05  Increasing.
                                                                                                   California stock.
Guadalupe fur seal..............           NA                  0                  0            0  7,408 (3,028)--                 NA  Increasing.
                                                                                                   Mexico to CA
                                                                                                   stock.
--------------------------------------------------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ Planned action area (12,593 km\2\) in the Santa Barbara Channel off the coast of California.
\2\ OBIS-SEAMAP SERDP-SDSS NMFS SWFSC summer density data for the California Current ecosystem.
\3\ Redfern et al. (2013)
\4\ Calculated take is the estimated number of animals in the in-water ensonified buffer zone multiplied by the number of days (18.6).
\5\ Calculated take is the estimated number of animals in the in-air ensonified buffer zone multiplied by the number of days (18.6).
\6\ Authorized take includes calculated takes for animals in the ensonified in-water and in-air buffer zones. Authorized takes for cetaceans were
  increased to account for group size.
\7\ NMFS Marine Mammal Stock Assessment Reports (Caretta et al., 2013)
\8\ Total authorized (and calculated) takes expressed as percentages of the species or stock.

    Numbers of marine mammals that might be present and potentially 
disturbed are estimated based on the available data about marine mammal 
distribution and densities in the Santa Barbara Channel action area. 
ExxonMobil estimated the number of different individuals of marine 
mammal species that may be exposed to in-water and in-air sounds with 
received levels greater than or equal to 160 dB re 1 [mu]Pa (rms) and 
in-air sounds with received levels greater than or equal to 90 dB re 20 
[mu]Pa (rms) (for harbor seals)/100 dB re 20 [mu]Pa (rms) (for all 
other pinniped species) for impact hammer pipe-driving activities on 
one or more occasions by considering the total marine area that will be 
within the 160 dB in-water radius and 90 dB (for harbor seals)/100 dB 
(for all other pinniped species) in-air radius around the impact hammer 
pipe-driving on at least one occasion and the expected density of 
marine mammals in the area (in the absence of the conductor pipe 
installation activities). The number of possible exposures can be 
estimated by considering the total marine area that will be within the 
in-water 160 dB radius and in-air 90 dB (for harbor seals)/100 dB (for 
all other pinniped species) radius around the impact hammer pipe-
driving activities. The in-water 160 dB and in-air 90dB (harbor seal)/
100 dB (for all other pinniped species) radii are based on acoustic 
modeling data for the impact hammer pipe-driving activities that may be 
used during the action (see the addendum to the IHA application). It is 
unlikely that a particular animal will stay in the area during the 
entire impact hammer pipe-driving activities.
    The number of different individuals potentially exposed to received 
levels greater than or equal to 160 dB re 1 [mu]Pa (rms) for in-water 
noise and 90 dB re 20 [mu]Pa (rms) (for harbor seals)/100 dB re 20 
[mu]Pa (rms) (for all other pinniped species) for in-air noise from 
impact hammer pipe-driving activities was calculated by multiplying:
    (1) The expected species density (in number/km\2\), times
    (2) The anticipated area to be ensonified to that level during 
conductor pipe installation (buffer zone = [pi] x [maximum 
distance]\2\), times
    (3) The number of days of the conductor pipe installation 
activities.
    NMFS notes that ExxonMobil had estimated the total number of days 
of the conductor pipe installation activities as 4.125 in its 
application, based on the total number of estimated hours of impact 
pipe-driving. NMFS received comments during the public comment period 
stating that this approach underestimates the number of days of actual 
exposure to the installation activities because pipe-driving sessions 
will be interspersed between periods of no pipe-driving. Specifically, 
the Commission commented that ExxonMobil should have added 3.3 hours of 
estimated pile-driving per section to 7.3 hours of downtime per section 
for a total of 10.6 hours per section of pipe. Multiplying that by the 
projected seven sections to be driven for each conductor pipe would 
result in a total of 74.2 hours, which when divided by 24 hours per day 
equates to 3.1 days of potential exposure per pipe. Using this method 
would yield a total of 18.6 days of potential exposure (3.1 days per 
conductor pipe multiplied by 6 pipes), which more accurately represents 
the total duration of proposed conductor pipe installation activities 
for all six conductor pipes. NMFS agrees, and revised the total number 
of days of installation activities to 18.6.
    Applying the approach described above, approximately 0.3318 km\2\ 
will be ensonified within the in-water 160 dB isopleth and 
approximately 0.0053 km\2\/0.0475 km\2\ will be ensonified within the 
in-air 90 dB (harbor seals)/100 dB (for all other pinniped species) 
isopleths for impact hammer pipe-driving activities (assuming 
omnidirectional spreading of sound from the conductor pipe) during the 
conductor pipe installation activities. The take calculations within 
the action area account for animals in the initial density snapshot and 
account for new (i.e., turnover) or previously exposed animals over an 
approximate 18.6 day period that approach and enter the area ensonified 
above or equal to the 160 dB isopleth for in-water noise and 90/100 dB 
isopleth for in-air noise from the impact hammer pipe-driving 
activities; however, studies suggest that many marine mammals will 
avoid exposing themselves to sounds at these levels, which suggests 
that there will not necessarily be a large number of new animals 
entering the action area once the conductor pipe installation 
activities

[[Page 58943]]

started. Also, the approach assumes that no cetaceans or pinnipeds will 
move away or toward the Harmony Platform. The take estimates represent 
the number of individuals that are expected (in absence of conductor 
pipe installation activities) to occur over an approximate 18.6 day 
period of time in the waters that will be exposed to greater than or 
equal to 160 dB (rms) in-water and greater than or equal to 90/100 dB 
(rms) in-air for impact hammer pipe-driving activities.
    ExxonMobil's estimates of exposures to various sound levels assume 
that the planned activities will be carried out in full. The estimates 
of the numbers of marine mammals potentially exposed to 160 dB (rms) 
for in-water noise and 90 dB re 20 [mu]Pa (rms) (for harbor seals)/100 
dB re 20 [mu]Pa (rms) (for all other pinniped species) for in-air noise 
received levels are precautionary and probably overestimate the actual 
numbers of marine mammals that could be involved. These estimates 
include standard contingencies for weather, equipment, or mitigation 
delays in the time planned for the planned activities. The authorized 
takes were increased for certain marine mammal species (i.e., gray, 
humpback, minke, sei, fin, blue, sperm, Baird's beaked, Cuvier's 
beaked, Mesoplodont beaked, killer, and short-finned pilot whales and 
bottlenose, striped, short-beaked common, long-beaked common, Pacific 
white-sided, northern right whale, and Risso's dolphins and Dall's 
porpoise) to account for group behavior. Based on recommendations from 
the CCC received during the 30-day public comment period on the notice 
of the proposed IHA (79 FR 36743, June 30, 2014), NMFS has authorized 
takes for Bryde's whales and false killer whales, which are considered 
warmer water species.
    Table 7 shows the estimates of the number of different individual 
marine mammals anticipated to be exposed to greater than or equal to 
160 dB re 1 [mu]Pa (rms) for the conductor pipe installation activities 
if no animals moved away from the Harmony Platform. No takes by Level A 
harassment have been authorized. The total take authorization is given 
in the fifth column of Table 7.

Encouraging and Coordinating Research

    ExxonMobil will coordinate the planned marine mammal monitoring 
program associated with the conductor pipe installation activities with 
researchers and other parties that express interest in this activity, 
area, and anthropogenic sound effects on marine mammals. ExxonMobil 
will coordinate with applicable U.S. agencies (e.g., NMFS), and will 
comply with their requirements.
    ExxonMobil supports research on marine mammals and sound in the 
environment through academic, industry, and private sector 
collaborations. ExxonMobil is a founding member and largest contributor 
to the Sound and Marine Life Joint Industry Program (JIP) through the 
International Oil and Gas Producers (OGP), and the International 
Association of Geophysical Contractors (IAGC). Through JIP and other 
venues, ExxonMobil provides annual funding and support for fundamental 
and applied scientific research to better understand the effects of 
anthropogenic sound on marine life. ExxonMobil also conducts internal 
research and monitoring programs specific to sound effects from 
exploration and production activities. These efforts have helped 
produce effective mitigation strategies and techniques to reduce 
potential sound effects on marine mammals from their operations and 
those from the oil and gas industry as a whole. More information on 
selected examples of ExxonMobil's involvement and contributions to 
scientific research on marine mammals and sound can be found in section 
14 of the IHA application.

Impact on Availability of Affected Species or Stock for Taking for 
Subsistence Uses

    Section 101(a)(5)(D) of the MMPA also requires NMFS to determine 
that the authorization will not have an unmitigable adverse effect on 
the availability of marine mammal species or stocks for subsistence 
use. There are no relevant subsistence uses of marine mammals 
implicated by this action. Therefore, NMFS has determined that the 
total taking of affected species or stocks will not have an unmitigable 
adverse impact on the availability of such species or stocks for taking 
for subsistence purposes.

Analysis and Determinations

Negligible Impact

    Negligible impact is ``an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival'' (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes, 
alone, is not enough information on which to base an impact 
determination. In addition to considering estimates of the number of 
marine mammals that might be ``taken'' through behavioral harassment, 
NMFS must consider other factors such as the likely nature of any 
responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), as 
well as the number and nature of estimated Level A harassment takes, 
the number of estimated mortalities, and effects on habitat.
    In making a negligible impact determination, NMFS evaluated factors 
such as:
    (1) The number of anticipated injuries, serious injuries, or 
mortalities;
    (2) The number, nature, and intensity, and duration of Level B 
harassment (all relatively limited); and
    (3) The context in which the takes occur (i.e., impacts to areas of 
significance, impacts to local populations, and cumulative impacts when 
taking into account successive/contemporaneous actions when added to 
baseline data);
    (4) The status of stock or species of marine mammals (i.e., 
depleted, not depleted, decreasing, increasing, stable, impact relative 
to the size of the population);
    (5) Impacts on habitat affecting rates of recruitment/survival; and
    (6) The effectiveness of monitoring and mitigation measures.
    As described above and based on the following factors, the 
specified activities associated with the conductor pipe installation 
activities are not likely to cause PTS, or other non-auditory injury, 
serious injury, or death. The factors include:
    (1) The likelihood that marine mammals are expected to move away 
from a noise source that is annoying prior to its becoming potentially 
injurious;
    (2) The potential for temporary or permanent hearing impairment is 
relatively low and will likely be avoided through the implementation of 
the required monitoring and mitigation (i.e., shut-down) measures;
    (3) The fact that cetaceans and pinnipeds will have to be closer 
than 10 m and 3.5 m, respectively, during impact hammer pipe-driving 
activities to be exposed to levels of underwater sound believed to have 
a minimal chance of causing a permanent threshold shift (PTS; i.e., 
Level A harassment); and
    (4) The likelihood that marine mammal detection ability by trained

[[Page 58944]]

PSOs is high at close proximity to the platform.
    No injuries, serious injuries, or mortalities are anticipated to 
occur as a result of ExxonMobil's planned conductor pipe installation 
activities, and none are authorized by NMFS. Table 7 of this document 
outlines the number of authorized Level B harassment takes that are 
anticipated as a result of these activities. NMFS's practice has been 
to apply the 160 dB re 1 [mu]Pa (rms) received level threshold for 
underwater impulse sound levels to determine whether take by Level B 
harassment occurs. Southall et al. (2007) provide a severity scale for 
ranking observed behavioral responses of both free-ranging marine 
mammals and laboratory subjects to various types of anthropogenic sound 
(see Table 4 in Southall et al. [2007]). Current NMFS practice, 
regarding exposure of marine mammals to high-level in-air sounds, as a 
threshold for potential Level B harassment, is at or above 90 dB re 20 
[mu]Pa for habor seals and at or above 100 dB re 20 [mu]Pa for all 
other pinniped species (Lawson et al., 2002; Southall et al., 2007). 
NMFS has not determined Level A harassment thresholds for marine 
mammals for in-air noise.
    As mentioned previously, NMFS estimates that 32 species of marine 
mammals under its jurisdiction could be potentially affected by Level B 
harassment over the course of the IHA. The population estimates for the 
marine mammal species that may be taken by Level B harassment were 
provided in Table 4 and 7 of this document. Due to the nature, degree, 
and context of Level B (behavioral) harassment anticipated and 
described (see ``Potential Effects on Marine Mammals'' section above) 
in this notice, the planned activity is not expected to impact rates of 
annual recruitment or survival for any affected species or stock, 
particularly given NMFS's and the applicant's requirement to implement 
mitigation, monitoring, and reporting measures to minimize impacts to 
marine mammals. Additionally, the conductor pipe installation 
activities will not adversely impact marine mammal habitat.
    For the marine mammal species that may occur within the action 
area, there are no known designated or important feeding and/or 
reproductive areas. Many animals perform vital functions, such as 
feeding, resting, traveling, and socializing, on a diel cycle (i.e., 24 
hr cycle). Behavioral reactions to noise exposure (such as disruption 
of critical life functions, displacement, or avoidance of important 
habitat) are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). 
Potential impacts are not likely to be significant from the pipe-
driving activities as the use of the impact hammer will occur over 30 
intermittent intervals of 2.5 to 3.3 hours each interspersed with 
period of downtime, for a cumulative total of about 18.6 days of 
potential exposure spread out over a 91-day period. Additionally, the 
conductor pipe installation activities will be increasing sound levels 
in the marine environment in a relatively small area surrounding the 
Harmony Platform (compared to the range of the animals), and some 
animals may only be exposed to and harassed by sound for less than a 
day.
    Of the 37 marine mammal species under NMFS jurisdiction that may or 
are known to likely to occur in the action area, seven are listed as 
threatened or endangered under the ESA: North Pacific right, western 
North Pacific gray whale, humpback, sei, fin, blue, and sperm whale and 
Guadalupe fur seal. These species are also considered depleted under 
the MMPA. Of these ESA-listed species, incidental take has been 
requested to be authorized for humpback, sei, fin, blue, and sperm 
whales. There is generally insufficient data to determine population 
trends for the other depleted species in the action area. To protect 
these animals (and other marine mammals in the action area), ExxonMobil 
must cease impact hammer pipe-driving activities if any marine mammal 
enters designated exclusion zones. No injury, serious injury, or 
mortality is expected to occur and due to the nature, degree, and 
context of the Level B harassment anticipated, and the activities are 
not expected to impact rates of recruitment or survival.
    NMFS has determined, provided that the aforementioned mitigation 
and monitoring measures are implemented, the impact of conducting pipe-
driving activities in the Santa Barbara Channel off the coast of 
California, may result, at worst, in a modification in behavior and/or 
low-level physiological effects (Level B harassment) of certain species 
of marine mammals.
    Changes in diving/surfacing patterns, habitat abandonment due to 
loss of desirable acoustic environment, and cessation of feeding or 
social interaction are some of the significant behavioral modifications 
that could potentially occur as a result of the conductor pipe 
installation activities. While behavioral modifications, including 
temporarily vacating the area during the impact hammer pipe-driving 
activities, may be made by these marine mammal species to avoid the 
resultant acoustic disturbance, the availability of alternate areas 
within these areas for species and the short and sporadic duration of 
the conductor pipe installation activities have led NMFS to determine 
that the taking by Level B harassment from the specified activity will 
have a negligible impact on the affected species in the specified 
geographic region. NMFS believes that the length of the conductor pipe 
installation activities (approximately 18.6 days total), the 
requirement to implement mitigation measures (e.g., shut-down of impact 
hammer pipe-driving activities), and the inclusion of the monitoring 
and reporting measures, will reduce the amount and severity of the 
potential impacts from the activity to the degree that it will have a 
negligible impact on the species or stocks in the action area. Based on 
the analysis contained herein of the likely effects of the specified 
activity on marine mammals and their habitat, and taking into 
consideration the implementation of the required monitoring and 
mitigation measures, NMFS finds that the total marine mammal take from 
ExxonMobil's conductor pipe installation activities will have a 
negligible impact on the affected marine mammal species or stocks.

Small Numbers

    The estimate of the number of individual cetaceans and pinnipeds 
that could be exposed to pipe-driving sounds with received levels 
greater than or equal to 160 dB re 1 [mu]Pa (rms) for all marine 
mammals for in-water sound levels and at or above 90 dB re 20 [mu]Pa 
for harbor seals and at or above 100 dB re 20 [mu]Pa for all other 
pinniped species for in-air sound levels during the conductor pipe 
installation activities is in Table 7 of this document.
    In total, 10 gray, 2 humpback, 2 minke, 2 Bryde's, 2 sei, 2 fin, 2 
blue, and 2 sperm whale could be taken by Level B harassment during the 
conductor pipe installation activities, which will represent 0.05, 
0.05, 0.2, unknown, 0.8, 0.03, 0.06, and 0.21% of the stock 
populations, respectively. Some of the cetaceans potentially taken by 
Level B harassment are delphinids and porpoises with estimates of 1 
pygmy sperm, 6 Baird's beaked, 4 Cuvier's beaked, 2 Mesoplodon spp. 
beaked, 10 killer, 50 false killer, and 40 short-finned pilot whale, 10 
bottlenose, 20 striped, 450 short-beaked common, 120 long-beaked 
common, 20 Pacific white-sided, 100 northern right whale, and 10 
Risso's dolphin as well as 50 Dall's porpoise, which will represent 
0.17, 0.71, 0.06, 0.29, 4.17/2.89/2.82, unknown, 5.26, 0.99, 0.18, 
0.11, 0.11,

[[Page 58945]]

0.11, 1.19, 0.16, and 0.12% of the affected stock populations, 
respectively. The pinnipeds that could potentially be taken by Level B 
harassment are the California sea lion, Pacific harbor and northern 
elephant seal, and northern fur seal with estimates of 161, 21, 68, and 
6 individuals, which will represent 0.05, 0.07, 0.05, and 0.05% of the 
affected stock populations, respectively.
    NMFS has determined that the authorized take estimates represent 
small numbers relative to the affected species or stocks sizes (i.e., 
all are less than 6%). Based on the analysis contained herein of the 
likely effects of the specified activity on marine mammals and their 
habitat, and taking into consideration the implementation of the 
mitigation and monitoring measures, NMFS finds that small numbers of 
marine mammals will be taken relative to the populations of the 
affected species or stocks. See Table 7 for the authorized take numbers 
of marine mammals.
    No known current regional population or stock abundance estimates 
for the northeast Pacific Ocean offshore of California are available 
for the two species under NMFS's jurisdiction that could potentially be 
affected by Level B harassment over the course of the IHA. These 
species include the Bryde's whale and false killer whale. Bryde's 
whales are distributed worldwide in tropical and sub-tropical waters 
and their occurrence in the action area is rare. Surveys have shown 
them to be common and distributed throughout the eastern tropical 
Pacific Ocean with a concentration around the equator east of 110[deg] 
West and a reduction west of 140[deg] West. Bryde's whales in 
California are likely to belong to a larger population inhabiting at 
least the eastern part of the tropical Pacific Ocean. In the western 
North Pacific Ocean, Bryde's whale abundance in the early 1980s was 
estimated to be 22,000 to 24,000 (Tillman and Mizroch, 1982; Miyashita, 
1986). Bryde's whale abundance has never been estimated for the entire 
eastern Pacific Ocean; however, a portion of that stock in the eastern 
tropical Pacific Ocean was estimated as 13,000 (Wade and Gerrodette, 
1993). The false killer whale is distributed worldwide throughout warm 
temperate and tropical oceans and their occurrence in the action area 
is rare. In the North Pacific Ocean, this species is well known from 
southern Japan, Hawaii, and the eastern tropical Pacific Ocean. This 
species occurs in the U.S. waters of the northern Gulf of Mexico, 
Hawaiian Islands, around Palmyra and Johnston Atolls, and American 
Samoa.
    These two species did not have density model outputs within the 
SERDP/NASA/NOAA and OBIS-SEAMAP database. However, limited OBIS-SEAMAP 
sightings data exist for these species within or adjacent to the action 
area. Even where the limited number of sightings suggests that density 
is very low and encounters are less likely, for any species with OBIS-
SEAMAP sightings data within or adjacent to the action area, NMFS 
believes it is wise to include coverage for potential takes. Generally, 
to quantify this coverage, NMFS assumed that ExxonMobil could 
potentially encounter one group of each species during the conductor 
pipe installation activities, and NMFS thinks it is reasonable to use 
the average group size to estimate the take from these potential 
encounters. Therefore, even though we do not have abundance data for 
these species, because of the limited sightings and low probability of 
encountering them, we have predicted take of no more than one 
individual group of each of these species of animals during the 
conductor pipe installation activities. Qualitatively, given what is 
known about cetacean biology and the range of these species, one group 
as a portion of the total population abundance within the U.S. EEZ 
would be considered small for both species.

Endangered Species Act

    Of the species of marine mammals that may occur in the action area, 
several are listed as threatened or endangered under the ESA, including 
the North Pacific right, western North Pacific gray, humpback, sei, 
fin, blue, and sperm whale and Guadalupe fur seal. ExxonMobil did not 
request take of endangered North Pacific right whales, western North 
Pacific gray whales, or Guadalupe fur seals due to the low likelihood 
of encountering these species during the pipe-driving activities. 
NMFS's Office of Protected Resources, Permits and Conservation 
Division, initiated formal consultation under section 7 of the ESA with 
NMFS's West Coast Regional Office, Protected Resources Division, to 
obtain a Biological Opinion evaluating the effects of issuing the IHA 
to ExxonMobil under section 101(a)(5)(D) of the MMPA on threatened and 
endangered marine mammals. NMFS's Biological Opinion concluded that the 
action and issuance of the IHA are not likely to jeopardize the 
continued existence of listed species and included an Incidental Take 
Statement incorporating the requirements of the IHA as Terms and 
Conditions. The Biological Opinion also concluded that designated 
critical habitat of these species does not occur in the action area.

National Environmental Policy Act

    To meet National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et 
seq.) requirements published by the Council of Environmental Quality 
(CEQ) and NOAA Administrative Order 126-6, Environmental Review 
Procedures for Implementing the National Environmental Policy Act, NMFS 
conducted a NEPA analysis to evaluate the effects of authorizing the 
take of marine mammals. NMFS prepared an Environmental Assessment 
titled ``Environmental Assessment on the Issuance of an Incidental 
Harassment Authorization to ExxonMobil Production Company to Take 
Marine Mammals by Harassment Incidental to Conductor Pipe Installation 
Activities at Harmony Platform in the Santa Barbara Channel offshore of 
California.'' NMFS has determined that the issuance of the IHA is not 
likely to result in significant impacts on the human environment and 
issued a Finding of No Significant Impact (FONSI).

Authorization

    NMFS has issued an IHA to ExxonMobil for the take, by Level B 
harassment, of small numbers of marine mammals incidental to conducting 
conductor pipe installation activities at Harmony Platform in Santa 
Barbara Channel offshore of California, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated.

     Dated: September 19, 2014.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2014-22758 Filed 9-29-14; 8:45 am]
BILLING CODE 3510-22-P