[Federal Register Volume 79, Number 125 (Monday, June 30, 2014)]
[Notices]
[Pages 36743-36769]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-15224]


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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; proposed Incidental Harassment Authorization; request 
for comments.

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SUMMARY: NMFS has received an application from ExxonMobil Production 
Company (ExxonMobil), a Division of ExxonMobil Corporation, for an 
Incidental Harassment Authorization (IHA) to take marine mammals, by 
harassment, 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. Pursuant 
to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments 
on its proposal to issue an IHA to ExxonMobil to incidentally harass, 
by Level B harassment only, 30 species of marine mammals during the 
specified activity.

DATES: Comments and information must be received no later than July 30, 
2014.

ADDRESSES: Comments on the application should be addressed 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. The mailbox 
address for providing email comments is [email protected]. 
Comments sent via email, including all attachments, must not exceed a 
25-megabyte file size. NMFS is not responsible for comments sent to 
addresses other than the one provided here.
    Instructions: All comments received are a part of the public record 
and will

[[Page 36744]]

generally be posted to http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications without change. All Personal Identifying 
Information (for example, name, address, etc.) voluntarily submitted by 
the commenter may be publicly accessible. Do not submit Confidential 
Business Information or otherwise sensitive or protected information.
    An electronic copy of the application may be obtained by writing to 
the address specified above, telephoning the contact listed below (see 
FOR FURTHER INFORMATION CONTACT) or visiting the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. Documents 
cited in this notice may also be viewed, by appointment, during regular 
business hours, at the aforementioned address.
    NMFS is also preparing an Environmental Assessment (EA) in 
accordance with the National Environmental Policy Act (NEPA) and will 
consider comments submitted in response to this notice as part of that 
process. The EA will be posted at the foregoing Internet site once it 
is finalized.

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 proposed project's estimates dates are from mid-August to mid-
November 2014, but the proposed action could occur anytime within a 12-
month period from the effective date of the proposed 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 30 
species is anticipated to result from the proposed activities.

Description of the Proposed Specified Activity

Overview

    ExxonMobil proposes 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 proposed conductor pipe installation 
activities would occur from mid-August to mid-November 2014, but the 
proposed activities could occur anytime within a 12-month period from 
the effective date of the proposed IHA. Precise scheduling is not 
presently available due to logistical and regulatory uncertainties. 
ExxonMobil has requested the IHA for an August start date to allow for 
flexibility in scheduling operations, equipment, and personnel, as well 
as to ensure sufficient time to arrange for monitoring field services. 
The estimated duration of the proposed project is 91 days. Under normal 
working conditions, the proposed 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 
would 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 proposed activities over the approximate three 
month duration. Of the estimated 84 days, hammer driving would occur 
over 30 intermittent intervals of 2.5 to 3.3 hours each for a combined 
total of 4.125 days, or 5% of the entire proposed project (3.3 hours x 
5 joints x 6 conductors = 99 hours or 4.125 days).

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 
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

[[Page 36745]]

bathymetry, and Santa Barbara area boundaries.
    Site Bathymetry and Sediment Physical Characteristics--Harmony 
Platform is located below a relatively steep (7.5%) descent from the 
shelf margin, which is defined by the 100 m contour in this area (USGS, 
2009). It sits at a water depth of 366 m, just above the northern rim 
of the Santa Barbara Basin which is roughly confined by the 400 m 
(1,312.3 ft) contour, descending to depths exceeding 600 m (1,968.5 
ft). Depths below the Harmony Platform are defined by a gentle slope 
(ca. 1%), which extends to the 600 m contour at the basin maximum. To 
the west of the platform, the slope attenuates to about 3% grade 
between 100 m and 400 m contours, near the western sill of the basin. 
To the east, the slope becomes steeper, approaching 15% grade between 
100 m and 400 m contours, at 20 km (10.8 nmi) east of the platform.
    Harmony Platform is located on unconsolidated fine-grained silty-
clay and clayey-silt sediments. Table 2-1 of the IHA application 
describes the sediment physical characteristics and geoacoustical 
profile in the vicinity of the Harmony Platform. These sediments are 
typical of slope depths proceeding into the basin where sediments may 
be 2,000 m (6,561.7 ft) thick. Stein (1995) reported similar sediment 
grain characteristics from core segments penetrating 196 m (643.1 ft) 
below the sediment surface at a basin depth of 565 m (1,853.7 ft). 
Sediments were primarily of terrigeneous origin, dominated by quartz 
and clay minerals montmorillonite and illite. These sediments are 
similar in quartz content and clay-mineral composition to suspended 
sediment introduced by the Santa Clara River, which has an average 
annual sediment load of about 600,000 m\3\ (2.1 x 10\7\ ft\3\) 
(Brownlee and Taylor, 1981). These turbid sediment plumes, arising 
primarily from the Santa Clara River to the east and from Santa Maria 
and Santa Inez Rivers north of Point Conception, may extend more than 5 
km (2.7 nmi) from shore and inshore from Harmony Platform during 
periods of heavy runoff.
    Sediments at Harmony Platform and throughout the Santa Barbara 
Channel slopes and basin reflect terrigeneous origins from coastal 
watersheds (mainly the Santa Clara River), with relatively minor 
inclusions of marine biogenic origin (e.g., calcareous and diatomaceous 
fractions). Shell fragment debris dislodged from the jacket structure 
during peak storm wave surges and from periodic maintenance has been 
observed around the periphery of the jacket in ROV surveys, but 
significant debris was not observed at the conductor pipe locations 
designated from this project. No known hard substrates have been 
identified by the former Minerals Management Service and NMFS surveys 
within 5 km of the Harmony Platform (Keller et al., 2005). Extending 
from shore to the 100 m shelf break, hard substrate is common, 
supporting extensive kelp beds at depths less than 20 m (65.6 ft), on 
cobbles and boulders. Further offshore, at depths of about 65 m (213.3 
ft) to the shelf break, regions of folded ridges and pinnacles up to 3 
m (9.8 ft) in relief have been recorded (USGS, 2009).
    Hydrodynamics and Water Column Physical Properties--Hydrodynamic 
and seawater properties at the Harmony Platform are complex as a result 
of shifting wind and current patterns that occur in the Santa Barbara 
Channel in response to changing coastline orientation at Point 
Conception (Beckenbach, 2004). The Santa Barbara Channel is a cross-
roads for large scale water masses moving along the California coast. 
Waters from north of Point Conception are cooled by coastal upwelling 
as they move southward. Most of these waters pass outside the Channel 
Islands but some enter the Santa Barbara Channel at its west end. 
Warmer waters from the south are driven poleward by the Southern 
California Countercurrent. Mean nearshore circulation in the entire 
Southern California Bight is dominated by this current (Hickey, 1993), 
which enters the Santa Barbara Channel from the east. Water mass 
properties are determined by relative inputs to the Santa Barbara 
Channel from eastern and western entrances.
    Hydrodynamics--Aud et al. (1999) determined that transport from the 
east accounted for 60% of the water entering the Santa Barbara Channel 
with 33% originating from the southern portion of the western entrance 
and the remaining 7% from southern inter-island passages. These 
contrasting source waters mix in the Santa Barbara Channel, often 
forming complex patterns visible in satellite images of sea surface 
temperature. They represent the more persistent large scale movement of 
water masses, which are driven by dynamic processes on scales much 
larger than the Santa Barbara Channel. Current speed fluctuations 
exhibit significant variation, typically ranging from 10 to 40 cm 
s-1 (Hickey, 1992), extending to a depth of 200 m (656.2 
ft), and tending to follow longshore isobaths. Seasonal mean currents 
over the continental slope are 20 to 30 cm s-1. However, 
surface circulation may be driven by winds that create rapidly 
developing high energy surface flows that vary in direction over scales 
of several kilometers. In the Santa Barbara Channel, wind stress from 
the northwest creates surface flows characterized by cyclonic, and 
occasionally anti-cyclonic, flow vortices which propagate westward. 
These occur intermittently throughout the year, and may last for months 
(Beckenbach, 2004; Oey, 2001). Vertical upwelling along the coast is 
also a feature of the water mass, occurring primarily from spring 
through fall (Harms and Winant, 1998). Inlet water mass movement in the 
vicinity of Harmony Platform is from west to east, extending to basin 
sill depth, with highly variable patterns of flow at the surface under 
the periodic influence of gyre vortices lasting from days to months, 
meandering from east to west, typically from spring to fall.
    Water Column Physical Properties--Seasonal changes in water column 
stability (density structure) result from changes in temperature and 
salinity that occur seasonally from air-sea surface interactions, and 
from periodic fluctuations in relative contributions of different 
source waters (e.g., eastern and western flows). The water column is 
density stratified as temperatures decline and salinity increases with 
depth. Seasonal effects are evident with the strongest density gradient 
occurring during summer months, primarily within the upper 25 m (82 
ft). Water column profiles of salinity, temperature, and calculated 
sound speed are illustrated in Figure 2-2 of the IHA application. 
Temperatures range from approximately 13 to 16.5[deg] Celsius (C) (55.4 
to 61.7[deg] Fahrenheit [F]) at the surface, become nearly isothermal 
(9 to 9.5[deg] C or 48.2 to 49.1[deg] F) at 150 m (492.1 ft) depth, 
likely varying little to the platform depth of 366 m (1,200.8 ft). 
Seasonal salinities varied little, ranging from about 33.3 to 33.7% at 
the surface to 34 to 34.1% to 150 m depth. Figure 2-2 of the IHA 
application shows salinity, temperature, and underwater sound speed 
profiles in the vicinity of the Harmony Platform derived from the U.S. 
Naval Oceanographic Office's Generalized Digital Environmental Model 
(GDEM) database. The profile for sound speed correlates strongly with 
temperature, which is the main determinant of water density structure.

Detailed Description of the Proposed Specified Activity

    ExxonMobil propose to install six conductor pipes by hydraulic 
hammering at Harmony Platform. The proposed conductor pipe installation 
activities are estimated to occur from mid-August to mid-November 2014, 
but

[[Page 36746]]

the proposed action could occur anytime within a 12-month period from 
the effective date of the proposed 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, formally 
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). Pile-driving the conductors are the only proven 
installation method that enables management of potential interferences 
with the existing platform infrastructure that would also reach the 
target depth. Non-pile-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 would 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 would 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) would 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 would require hydraulic 
driving. The S-90 IHC hydraulic hammer would sit on the conductor 
throughout pile-driving operations, but a ram internal to the hammer 
would stroke back and forth using hydraulic pressure to impart energy 
to the conductor. No physical dropping of a weight would 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 
would take 3.5 to 7.3 hours per section, mostly depending on the type 
of welding equipment used (e.g., automated welder). Hammer pile-driving 
would 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 
would 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 Proposed Installation Activities and Associated Characteristics of Each Conductor Pipe at
                                                Harmony Platform.
----------------------------------------------------------------------------------------------------------------
                                                                                                      Estimated
     Conductor pipe activity          Pipe length (m)     Estimates number of      Pile-driving       number of
                                                                joints               required         days \3\
----------------------------------------------------------------------------------------------------------------
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
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
----------------------------------------------------------------------------------------------------------------
\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.


[[Page 36747]]

Platform Specifications

    The Harmony Platform is owned and operated by ExxonMobil and has a 
personnel capacity of 132 people. The Harmony Platform, located in the 
Santa Barbara Channel, was installed on June 21, 1989 and first began 
production on December 30, 1993. The lease location for the Santa Ynez 
Production Unit is OCS-P0190. Support vessels and helicopters are used 
routinely as part of normal platform operations and would be utilized 
to provide necessary support for proposed activities during the 
project. There are no anticipated changes in logistics from current 
operations associated with the proposed project. The contractors 
responsible for protected species and noise monitoring during the 
proposed project would use existing, routine transportation vessels.
    The Harmony Platform also has a minimum of two locations as likely 
observation stations from which Protected Species Observers (PSO) would 
watch for marine mammals before and during the proposed conductor pipe 
installation activities. The station on the upper deck has an 
approximately 360[deg] view around the Harmony Platform to monitor the 
Level B harassment buffer zone. At least one station on the lower deck 
would monitor the Level A harassment exclusion zone. More details of 
the Harmony Platform can be found in the IHA application and online at: 
http://www.boem.gov/BOEM-Newsroom/Offshore-Stats-and-Facts/Pacific-Region/Pacific-Platform-Operators.aspx#Exxon.

Acoustic Source Specifications

Predicted Sound Levels for the Pile-Driving Activities
    The predicted in-water sound field during proposed impact hammer 
pile-driving of the conductor pipes at the Harmony Platform were 
modeled by JASCO Applied Sciences, Ltd (JASCO). See JASCO's 
``Assessment of Airborne and Underwater Noise from Pile-Driving 
Activities at the Harmony Platform'' for a detailed description of 
ExxonMobil's modeling for this proposed action, which is provided as an 
addendum to the IHA application. NMFS refers the reviewers to that 
document for additional information. Sound levels emitted from the 
conductor pipe were estimated using underwater recordings (Illingworth 
and Rodkin, 2007) for impact pile-driving of 61 to 76.2 centimeter (cm) 
(24 to 30 inch [in]) steel piles (i.e., pipes) back calculated to 1 m 
from the sound source, assuming a combination of cylindrical and 
spherical spreading. Sound level at the source was then scaled to the 
anticipated energy range of 9 and 90 kJ for the impact hammer and 
coupled to an acoustic model of a representative steel pipe (Claerbout, 
1976; Reinhall and Dahl, 2011). Only modeled results associated with 
the maximum hammer energy of 90 kJ were used to estimate potential 
impacts and calculate take.
    Each 505 m (1,656.8 ft) long conductor pipe is assembled from 12 m 
(39.4 ft) long sections welded end-to-end, and then lowered from a top 
deck of the platform through 366 m (1,200.8 ft) of water until the pipe 
encounters the seafloor and penetrates approximately 60 m of the seabed 
under its own weight. Because of the extremely long length of the 
conductor pipe compared to those represented in the literature, the 
pipe was modeled as a line array of 12 sources at 30 m (98.4 ft) 
intervals (i.e., over 360 m [1,181.1 ft] pipe length). This procedure 
produced a more realistic estimates of the maximum sound SPL (rms) from 
impact hammer pile-driving of Harmony Platform's conductor pipes, 
compared with a single sound source representation (e.g., mid-pipe) 
that is generally used for shorter pipes (piles). At the maximum hammer 
energy of 90 kJ, the corresponding maximum sound pressure throughout 
the water column is estimated at 202 dB (rms) at 1 m from the conductor 
pipe (see Figure 6-1 of the IHA application). The predicted sound 
levels were used by ExxonMobil and NMFS to determine the buffer and 
exclusion zones for the proposed conductor pipe installation 
activities.
    Table 2 (Table 6-4 of the IHA application) summarizes the modeled 
distances at which in-water (160, 180, and 190 dB [rms]) and in-air (90 
and 100 dB [rms]) sound levels are expected to be received from the 
impact hammer pile-driving operating at a water depth of 366 m. For in-
water noise, sound propagation and corresponding maximum distances were 
modeled using JASCO's model Full Waveform Range-dependent Acoustic 
Model (FWRAM), which is based on a modified version of the U.S. Navy's 
parabolic Range-dependent Acoustic Model (RAM) to account for an 
elastic seabed. FWRAM enhances RAM by accounting for seabed dissipation 
of acoustic energy and incorporates local bathymetry, seafloor 
geoacoustics, and underwater sound speed profiles. Physical data 
specific to the Harmony Platform location were used by JASCO to model 
sound propagation (see Table 2-1 and Figure 202 of the IHA 
application). Representative data include sediment grain size and 
density, and water column salinity/temperature, as these properties 
affect seafloor geoacoustic properties and in-water sound speed, 
respectively. Routines in FWRAM were used to model sound as SPL (rms) 
over water column depth and distance from the conductor pipe based on 
maximum hammer energy (90 kJ). Figure 6-2 of the IHA application shows 
water depth versus distance from the conductor pipe (sound source), 
where the 160 dB isopleth represents the maximum distance for in-water 
Level B harassment for marine mammals. The maximum distances are 
generally higher in the top 100 m (328.1 ft) of the water column.
    To evaluate potential seasonal effects on sound propagation in the 
water column, year-round conditions using selected monthly averages 
(i.e., January, April, August, and November) of water column salinity 
and temperature were modeled along one azimuth, south of the Harmony 
Platform. Results showed no significant seasonal variations (<1 dB 
[rms]) up to 1 km (0.5 nmi) from the Harmony Platform. Potential 
differences in sound propagation with direction from the Harmony 
Platform also were investigated by JASCO. There were not significant 
differences in the sound field modeled for four equally spaced 
transects out to 1 km from the Harmony Platform.
    For in-air noise, JASCO used in-air sound levels calculated from 
recordings of pipe-driving tests performed by ExxonMobil using a 90 kJ 
energy hammer that is planned for use on this proposed action. The 
tests used the S-90 hammer at 90% of its maximum energy with a steel 
pipe of unknown size. The estimated sound levels represent A-weighted 
received levels, calculated at six distances between 0 and 12 m (0 to 
39.4 ft), and indicated a source level of 132.4 dB re 20 [mu]Pa (rms) 
(A-weighted). Calculated distances from the sound source to the Level B 
harassment threshold for in-air noise (SPL [rms]) using spherical 
spreading loss are shown below and in Table 6-4 of the IHA application. 
Using the JASCO model, Table 2 (below) shows the distances at which 
three rms underwater sound levels and two rms in-air sound levels are 
expected to be received from the impact hammer pile-driving activities. 
The 180 and 190 dB re 1 [micro]Pam (rms) distances are the safety 
criteria (i.e., exclusion zone) for potential Level A harassment as 
specified by NMFS (2000) and are applicable to cetaceans and pinnipeds, 
respectively. If marine mammals are detected within or about to enter 
the appropriate exclusion zone, the impact hammer pile-driver would be 
shut-down immediately.

[[Page 36748]]



  Table 2--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 Proposed 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           190 dB           90 dB            100 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
90 kJ Impact Hammer Pile-Driver...................             366              325               10              3.5              123               41
                                                                       (1,066.3 ft)        (32.8 ft)        (11.5 ft)       (403.5 ft)       (134.5 ft)
--------------------------------------------------------------------------------------------------------------------------------------------------------

    NMFS expects that acoustic stimuli resulting from the proposed 
impact hammer pile-driving associated with the conductor pipe 
installation activities has the potential to harass marine mammals.
Description of the Marine Mammals in the Area of the Proposed Specified 
Activity
    The marine mammals that generally occur in the proposed 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 proposed action area 
in the Santa Barbara Channel off the coast of California (ranging from 
Point Conception and south, including the entire Southern California 
Bight) include 30 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 proposed IHA notice.
    Marine mammal species listed as threatened or endangered under the 
U.S. Endangered Species Act of 1973 (ESA; 16 U.S.C. 1531 et seq.), 
includes the North Pacific right (Eubalaena japonica), 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 proposed action area.
    Cetaceans occur throughout the Santa Barbara Channel proposed 
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 
30 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, Bryde's whale (Balaenoptera 
edeni), 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 proposed action area. The 
harbor porpoise occurs north of Point Conception, California. 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). 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 3 (below) presents information on the 
occurrence, abundance, distribution, population status, and 
conservation status of the species of marine mammals that may occur in 
the proposed project area during August to November 2014.

[[Page 36749]]



   Table 3--The Habitat, Occurrence, Range, Regional Abundance, and Conservation Status of Marine Mammals That May Occur in or Near the Proposed 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             ESA \2\            MMPA \3\
                                                                                                 (minimum) \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.      Pacific stock.
                                                       migrations.         California to       Pacific stock.     EN--Western North   D--Western North
                                                                           Arctic--Eastern    155 (142)--Western   Pacific             Pacific
                                                                           North Pacific       North Pacific       population.         population.
                                                                           stock.              population..
    Humpback whale (Megaptera     Pelagic, nearshore  Seasonal,           Cosmopolitan......  1,918 (1,876)--     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................  NL................  NC.
     edeni).                       coastal.            summer off          tropical zones
                                                       California.         between 40[deg]
                                                                           North and 40[deg]
                                                                           South.
    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      Deep waters off     Rare..............  Tropical to warm    NA--CA/OR/WA stock  NL................  NC.
     sima).                        the shelf.                              temperate zones
                                                                           (warmer
                                                                           preference).
    Baird's beaked whale          Pelagic...........  Primarily along     North Pacific       847 (466)--CA/OR/   NL................  NC.
     (Berardius bairdii).                              continental slope   Ocean and           WA stock.
                                                       late spring to      adjacent seas.
                                                       early fall.
    Cuvier's beaked whale         Pelagic...........  Possible year-      Cosmopolitan......  6,950 (4,481)--CA/  NL................  NC.
     (Ziphius 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           Pelagic...........  Rare, continental   Temperate and       694 (389)--         NL................  NC.
     (Mesoplodon 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.

[[Page 36750]]

 
    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)--Eastern
                                                       February).                              North Pacific
                                                                                               Transient stock..
                                                                                              354 (354)--West
                                                                                               Coast Transient
                                                                                               stock..
    Short-finned pilot whale      Pelagic, shelf,     Uncommon, more      Warm temperate to   760 (465)--CA/OR/   NL................  NC.
     (Globicephala                 coastal.            common before       tropical waters,    WA stock.
     macrorhynchus).                                   1982.               ~50[deg] North to
                                                                           40[deg] South.
    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.           between 45[deg]    323 (290)--
                                                      Coastal stock--      North and South.    California
                                                       Limited, small                          Coastal stock..
                                                       population 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                                   round, more         of North Pacific    CA/OR/WA,
     obliquidens).                                     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               Shelf, slope,       Common, more        North Pacific       42,000 (32,106)--   NL................  NC.
     (Phocoenoides 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           Coastal, shelf....  Common, Channel     Eastern North       296,750 (153,337)-- NL................  NC.
     (Zalophus 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        Coastal, pelagic    Common, haul-outs   Eastern and         124,000 (74,913)--  NL................  NC.
     (Mirounga 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             Pelagic, offshore.  Common, small       North Pacific       12,844 (6,722)--    NL................  NC.
     (Callorhinus 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 36751]]

 
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 proposed 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 proposed 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 pile-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 ``Proposed 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.

Acoustic Impacts

    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, 30 marine mammal species 
managed under NMFS jurisdiction (26 cetacean and 4 pinniped species) 
are likely to occur in the proposed action area. Of the 26 cetacean 
species likely to occur in ExxonMobil's proposed action area, 6 are 
classified as low-frequency cetaceans (i.e., gray, humpback, minke, 
sei, fin, and blue whale), 18 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, 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 (e.g., impact pile-
driving) and the 120 dB (rms) threshold for continuous noise

[[Page 36752]]

(e.g., vibratory pile-driving). No vibratory pile-driving is planned 
for ExxonMobil's proposed activity 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 proposed 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, would 
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 proposed project would 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 effects of pile-driving on marine mammals depend on several 
factors, including the size, type, and depth of the animal; the depth, 
intensity, and duration of the pile-driving sound; the depth of the 
water column; the substrate of the habitat; the standoff distance 
between the pile and the animals; and the sound propagation properties 
of the environment. Impacts to marine mammals from pile-driving 
activities are expected to result primarily from acoustic pathways. As 
such, the degree of effect is intrinsically related to the received 
level and duration of the sound exposure, which are in turn influenced 
by the distance between the animal and the source. The further away 
from the source, the less intense the exposure should be. The substrate 
and depth of the habitat affect the sound propagation properties of the 
environment. Shallow environments are typically more structurally 
complex, which leads to rapid sound attenuation. In addition, 
substrates that are soft (e.g., sand) would absorb or attenuate the 
sound more readily than hard substrates (e.g., rock), which may reflect 
the acoustic wave. Soft porous substrates would also likely require 
less time to drive the pipe, and possibly less forceful equipment, 
which would ultimately decrease the intensity of the acoustic source.
    In the absence of mitigation, impacts to marine mammal species may 
result from physiological and behavioral responses to both the type and 
strength of the acoustic signature (Viada et al., 2008). The type and 
severity of behavioral impacts are difficult to define due to limited 
studies addressing the behavioral effects of impulse sounds on marine 
mammals. Potential effects from impulsive sound sources can range in 
severity, ranging from effects such as behavioral disturbance, tactile 
perception, physical discomfort, slight injury, of the internal organs 
and the auditory system, to mortality (Yelverton et al., 1973).

Tolerance

    Richardson et al. (1995) defines tolerance as the occurrence of 
marine mammals in areas where they are exposed to human activities or 
man-made noise. In many cases, tolerance develops by the animal 
habituating to the stimulus (i.e., the gradual waning of responses to a 
repeated or ongoing stimulus) (Richardson, et al., 1995; Thorpe, 1963), 
but because of ecological or physiological requirements, many marine 
animals may need to remain in areas where they are exposed to chronic 
stimuli (Richardson, et al., 1995).
    Numerous studies have shown that pulsed underwater sounds from 
industry activities are often readily detectable in the water at 
distances of many kilometers. Several studies have shown that marine 
mammals at distances more than a few kilometers often show no apparent 
response (Miller et al., 2005; Bain and Williams, 2006). That is often 
true even in cases when the pulsed sounds must be readily audible to 
the animals based on measured received levels and the hearing 
sensitivity of the marine mammal group. Although various baleen whales 
and toothed whales, and (less frequently) pinnipeds have been shown to 
react behaviorally to airgun pulses under some conditions, at other 
times marine mammals of all three types have shown no overt reactions 
(e.g., Malme et al., 1986; Richardson et al., 1995; Madsen and Mohl, 
2000; Croll et al., 2001; Jacobs and Terhune, 2002; Madsen et al., 
2002; Miller et al., 2005). The relative responsiveness of baleen and 
toothed whales are quite variable.

Masking

    The term masking refers to the inability of a subject to recognize 
the occurrence of an acoustic stimulus as a result of the interference 
of another acoustic stimulus (Clark et al., 2009). Introduced 
underwater sound may, through masking, reduce the effective 
communication distance of a marine mammal species if the frequency of 
the source is close to that used as a signal by the marine mammal, and 
if the anthropogenic sound is present for a significant fraction of the 
time (Richardson et al., 1995).
    Natural and artificial sounds can disrupt behavior by masking, or 
interfering with, a marine mammal's ability to hear other sounds. 
Masking occurs when the receipt of a sound is interfered with by 
another coincident sound at similar frequencies and at similar or 
higher levels. Chronic exposure to excessive, though not high-
intensity, sound could cause masking at particular frequencies for 
marine mammals that utilize sound for vital biological functions. 
Masking can interfere with detection of acoustic signals such as 
communication calls, echolocation sounds, and environmental sounds 
important to marine mammals. Therefore, under certain circumstances, 
marine mammals whose acoustic sensors or environment are being severely 
masked could also be impaired from maximizing their performance fitness 
in survival and reproduction. If the coincident (masking) sound were 
man-made, it could be potentially harassing if it disrupted hearing-
related behavior. It is important to distinguish TTS and PTS, which 
persist after the sound exposure, from masking, which occurs during the 
sound exposure. Because masking (without resulting in threshold shift) 
is not associated with abnormal physiological function, it is not 
considered a physiological effect, but rather a potential behavioral 
effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. Because sound 
generated from in-water pile-driving is mostly concentrated at low 
frequency ranges, it may have less effect on high frequency 
echolocation sounds made by porpoises. However, lower frequency man-
made sounds are more likely to affect detection of communication calls 
and other potentially important natural sounds such as surf and prey 
sound. It

[[Page 36753]]

may also affect communication signals when they occur near the sound 
band and thus reduce the communication space of animals (e.g., Clark et 
al., 2009) and cause increased stress levels (e.g., Foote et al., 2004; 
Holt et al., 2009).
    Masking has the potential to impact species at population, 
community, or even ecosystem levels, as well as at individual levels. 
Masking affects both senders and receivers of the signals and can 
potentially have long-term chronic effects on marine mammal species and 
populations. Recent research suggests that low frequency ambient sound 
levels have increased by as much as 20 dB (more than three times in 
terms of SPL) in the world's ocean from pre-industrial periods, and 
that most of these increases are from distant shipping (Hildebrand, 
2009). All anthropogenic sound sources, such as those from vessel 
traffic, pile-driving, and dredging activities, contribute to the 
elevated ambient sound levels, thus intensifying masking. However, much 
of the sound generated from the proposed activities is not expected to 
contribute significantly to increased ocean ambient sound.
    Given that the energy distribution of pile-driving covers a broad 
frequency spectrum, sound from these sources would likely be within the 
audible range of marine mammals present in the proposed action area. 
Impact pile-driving activity is relatively short-term, with rapid 
pulses occurring for the duration of the driving event. The probability 
that impact pile-driving resulting from this proposed action would mask 
acoustic signals important to the behavior and survival of marine 
mammal species is likely to be discountable. Any masking event that 
could possibly rise to Level B harassment under the MMPA would occur 
concurrently within the zones of behavioral harassment already 
estimated for impact pile-driving, and which have already been taken 
into account in the exposure analysis.

Behavioral Disturbance

    Marine mammals may behaviorally react to sound when exposed to 
anthropogenic noise. Disturbance includes a variety of effects, 
including subtle to conspicuous changes in behavior, movement, and 
displacement. Behavioral responses to sound are highly variable and 
context-specific and reactions, if any, depend on species, state of 
maturity, experience, current activity, reproductive state, time of 
day, and many other factors (Richardson et al., 1995; Wartzok et al., 
2004; Southall et al., 2007; Weilgart, 2007).
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. Behavioral state may affect the type of response as well. For 
example, animals that are resting may show greater behavioral change in 
response to disturbing sound levels than animals that are highly 
motivated to remain in an area for feeding (Richardson et al., 1995; 
NRC, 2003; Wartzok et al., 2003).
    Controlled experiments involving exposure to loud impulse sound 
sources with captive marine mammals showed pronounced behavioral 
reactions, including avoidance of loud sound sources (Ridgeway et al., 
1997; Finneran et al., 2003). Observed responses of wild marine mammals 
to loud pulsed sound sources (typically seismic airguns or acoustic 
harassment devices, but also including impact pile-driving) have been 
varied but often consist of avoidance behavior or other behavioral 
changes suggesting discomfort (Morton and Symonds, 2002; Thorson and 
Reyff, 2006; see also Gordon et al., 2004; Wartzok et al., 2003; 
Nowacek et al., 2007).
    It is likely that the onset of pile-driving could result in 
temporary, short-term changes in an animal's typical behavior and/or 
avoidance of the affected action area. These behavioral reactions are 
often shown as: Changing durations of surfacing and dives, number of 
blows per surfacing, or moving direction and/or speed; reduced/
increased vocal activities; changing/cessation of certain behavioral 
activities (such as socializing or feeding); visible startle response 
or aggressive behavior (such as tail/fluke slapping or jaw clapping); 
avoidance of areas where noise sources are located; and/or flight 
responses (e.g., pinnipeds flushing into the water from haul-outs or 
rookeries). If a marine mammal does react briefly to an underwater 
sound by changing its behavior or moving a small distance, the impacts 
of the change are unlikely to be significant to the individual, let 
alone the stock or population. However, if a sound source displaces 
marine mammals from an important feeding or breeding area for a 
prolonged period, impacts on individuals and populations could be 
significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, and/or reproduction. Some of these 
significant behavioral modifications that could potentially lead to 
effects on growth, survival, or reproduction include:
     Change in diving/surfacing patterns (such as those thought 
to be causing beaked whale stranding due to exposure to military mid-
frequency tactical sonar);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cessation of feeding or social interaction.
    The onset of behavioral disturbance from anthropogenic noise 
depends on both external factors (characteristics of noise sources and 
their paths) and the specific characteristics of receiving animals 
(hearing, motivation, experience, demography) and is also difficult to 
predict (Richardson et al., 1995; Southall et al., 2007). Given the 
many uncertainties in predicting the quantity and types of impacts of 
noise on marine mammals, it is common practice to estimate how many 
mammals would be present within a particular distance of industrial 
activities and/or exposed to a particular level of sound. In most 
cases, this approach likely overestimates the numbers of marine mammals 
that would be affected in some biologically-important manner.

Hearing Impairment and Other Physical Effects

    Marine mammals exposed to high intensity sound repeatedly or for 
prolonged periods can experience hearing threshold shift, which is the 
loss of hearing sensitivity at certain frequency ranges (Kastak et al., 
1999; Schlundt et al., 2000; Finneran et al., 2002, 2005). Threshold 
shift can be permanent (PTS), in which case the loss of hearing 
sensitivity is not recoverable, or temporary (TTS), in which case the 
animal's hearing threshold would recover over time (Southall et al., 
2007). Marine mammals depend on acoustic cues for vital biological 
functions (e.g., orientation, communication, finding prey, avoiding 
predators); thus, TTS may result in reduced fitness in survival and 
reproduction. However, this depends on the frequency and duration of 
TTS, as well as the biological context in which it occurs. TTS of 
limited duration, occurring in a frequency range that does not coincide 
with that used for recognition of important acoustic cues, would have 
little to no effect on an

[[Page 36754]]

animal's fitness. Repeated sound exposures that lead to TTS could cause 
PTS. PTS, in the unlikely event that it occurred, would constitute 
injury, but TTS is not considered injury (Southall et al., 2007). It is 
unlikely that the project would result in any cases of temporary or 
especially permanent hearing impairment or any significant non-auditory 
physical or physiological effects for reasons discussed later in this 
document. Some behavioral disturbance is expected, but it is likely 
that this would be localized and short-term because of the short 
duration of the proposed action.
    Many marine mammals are likely to show some avoidance of the 
proposed action area where received levels of pile-driving sound high 
enough that hearing impairment could potentially occur. In those cases, 
the avoidance responses of the animals themselves would reduce or (most 
likely) avoid any possibility of hearing impairment. Non-auditory 
physical effects may also occur in marine mammals exposed to strong 
underwater pulsed sound.
    Temporary Threshold Shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to a strong sound (Kryter, 
1985). While experiencing TTS, the hearing threshold rises and a sound 
must be stronger in order to be heard. At least in terrestrial mammals, 
TTS can last from minutes or hours to (in cases of strong TTS) days. 
For sound exposures at or somewhat above the TTS threshold, hearing 
sensitivity in both terrestrial and marine mammals recovers rapidly 
after exposure to the noise ends. Few data on sound levels and 
durations necessary to elicit mild TTS have been obtained for marine 
mammals, and none of the published data concern TTS elicited by 
exposure to multiple pulses of sound. Available data on TTS in marine 
mammals are summarized in Southall et al. (2007). Table 2 (above) 
presents the estimated distances from the impact hammer during pile-
driving activities at which the received energy level (per pulse, flat-
weighted) would be expected to be greater than or equal to 180 and 190 
dB re 1 [micro]Pa (rms).
    To avoid the potential for injury (Level A harassment), NMFS (1995, 
2000) concluded that cetaceans and pinnipeds should not be exposed to 
pulsed underwater noise at received levels exceeding 180 and 190 dB re 
1 [mu]Pa (rms), respectively. The established 180 and 190 dB (rms) 
criteria are not considered to be the levels above which TTS might 
occur. Rather, they are the received levels above which, in the view of 
a panel of bioacoustics specialists convened by NMFS before TTS 
measurements for marine mammals started to become available, one could 
not be certain that there would be no injurious effects, auditory or 
otherwise, to marine mammals. NMFS also assumes that cetaceans and 
pinnipeds exposed to levels exceeding 160 dB re 1 [mu]Pa (rms) may 
experience Level B harassment.
    For toothed whales, researchers have derived TTS information for 
odontocetes from studies on the bottlenose dolphin and beluga whale 
(Delphinapterus leucas). The experiments show that exposure to a single 
impulse at a received level of 207 kPa (or 30 psi, p-p), which is 
equivalent to 228 dB re 1 Pa (p-p), resulted in a 7 and 6 dB TTS in the 
beluga whale at 0.4 and 30 kHz, respectively. Thresholds returned to 
within 2 dB of the pre-exposure level within 4 minutes of the exposure 
(Finneran et al., 2002). For the one harbor porpoise tested, the 
received level of airgun sound that elicited onset of TTS was lower 
(Lucke et al., 2009). If these results from a single animal are 
representative, it is inappropriate to assume that onset of TTS occurs 
at similar received levels in all odontocetes (cf. Southall et al., 
2007). Some cetaceans apparently can incur TTS at considerably lower 
sound exposures than are necessary to elicit TTS in the bottlenose 
dolphin or beluga whale.
    For baleen whales, there are no data, direct or indirect, on levels 
or properties of sound that are required to induce TTS. The frequencies 
to which baleen whales are most sensitive are assumed to be lower than 
those to which odontocetes are most sensitive, and natural background 
noise levels at those low frequencies tend to be higher. As a result, 
auditory thresholds of baleen whales within their frequency band of 
best hearing are believed to be higher (less sensitive) than are those 
of odontocetes at their best frequencies (Clark and Ellison, 2004). 
From this, it is suspected that received levels causing TTS onset may 
also be higher in baleen whales than those of odontocetes (Southall et 
al., 2007).
    In pinnipeds, researchers have not measured TTS thresholds 
associated with exposure to brief pulses (single or multiple) of 
underwater sound. Initial evidence from more prolonged (non-pulse) 
exposures suggested that some pinnipeds (harbor seals in particular) 
incur TTS at somewhat lower received levels than do small odontocetes 
exposed for similar durations (Kastak et al., 1999, 2005; Ketten et 
al., 2001). The TTS threshold for pulsed sounds has been indirectly 
estimated as being an SEL of approximately 171 dB re 1 [mu]Pa 
\2\[middot]s (Southall et al., 2007) which would be equivalent to a 
single pulse with a received level of approximately 181 to 186 dB re 1 
[mu]Pa (rms), or a series of pulses for which the highest rms values 
are a few dB lower. Corresponding values for California sea lions and 
northern elephant seals are likely to be higher (Kastak et al., 2005).
    Permanent Threshold Shift--When PTS occurs, there is physical 
damage to the sound receptors in the ear. In severe cases, there can be 
total or partial deafness, whereas in other cases, the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter, 
1985). There is no specific evidence that exposure to pulses of airgun 
or pile-driving sound can cause PTS in any marine mammal. However, 
given the possibility that mammals close to an airgun array might incur 
at least mild TTS, there has been further speculation about the 
possibility that some individuals occurring very close to airguns might 
incur PTS (e.g., Richardson et al., 1995, p. 372ff; Gedamke et al., 
2008). Single or occasional occurrences of mild TTS are not indicative 
of permanent auditory damage, but repeated or (in some cases) single 
exposures to a level well above that causing TTS onset might elicit 
PTS.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals but are assumed to be similar to those in humans and 
other terrestrial mammals (Southall et al., 2007). PTS might occur at a 
received sound level at least several dBs above that inducing mild TTS 
if the animal were exposed to strong sound pulses with rapid rise 
times. Based on data from terrestrial mammals, a precautionary 
assumption is that the PTS threshold for impulse sounds (such as an 
impact hammer pile-driving as received close to the source) is at least 
6 dB higher than the TTS threshold on a peak-pressure basis, and 
probably greater than 6 dB (Southall et al., 2007).
    Given the higher level of sound necessary to cause PTS as compared 
with TTS, it is considerably less likely that PTS would occur. Baleen 
whales generally avoid the immediate area around operating sound 
sources, as do some other marine mammals.
    Non-auditory Physiological Effects--Non-auditory physiological 
effects or injuries that theoretically might occur in marine mammals 
exposed to strong underwater sound include stress, neurological 
effects, bubble formation, resonance, and other types of organ or 
tissue damage (Cox et al., 2006; Southall et al., 2007). Studies 
examining such effects are limited.

[[Page 36755]]

    In general, very little is known about the potential for pile-
driving sounds (or other types of strong underwater sounds) to cause 
non-auditory physical effects in marine mammals. Such effects, if they 
occur at all, would presumably be limited to short distances from the 
sound source and to activities that extend over a prolonged period. The 
available data do not allow identification of a specific exposure level 
above which non-auditory effects can be expected (Southall et al., 
2007), or any meaningful quantitative predictions of the numbers (if 
any) of marine mammals that might be affected in those ways. Marine 
mammals that show behavioral avoidance of pile-driving, including most 
baleen whales, some odontocetes, and some pinnipeds, are especially 
unlikely to incur auditory impairment or non-auditory physical effects.

Airborne Sound Effects

    Marine mammals that occur in the proposed project area could be 
exposed to airborne sounds associated with pile-driving that have the 
potential to cause harassment, depending on their distance from pile-
driving activities. Airborne pile-driving sound would have less impact 
on cetaceans than pinnipeds because sound from atmospheric sources does 
not transmit well underwater (Richardson et al., 1995); thus, airborne 
sound would only be an issue for pinnipeds in the proposed action area, 
whether hauled-out or in the water with their heads in the air. Most 
likely, a sound would cause behavioral responses similar to those 
discussed above in relation to underwater sound. For instance, 
anthropogenic sound could cause hauled-out pinnipeds to exhibit changes 
in their normal behavior, such as reduction in vocalizations, or cause 
them to temporarily abandon their habitat and move further from the 
source. Studies by Blackwell et al. (2004) and Moulton et al. (2005) 
indicate a tolerance or lack of response to unweighted airborne sounds 
as high as 112 dB peak and 96 dB rms.
    The potential effects to marine mammals described in this section 
of the document do not take into consideration the proposed monitoring 
and mitigation measures described later in this document (see the 
``Proposed Mitigation'' and ``Proposed Monitoring and Reporting'' 
sections) which, as noted are designed to effect the least practicable 
impact on affected marine mammal species and stocks.

Anticipated Effects on Marine Mammal Habitat

    The proposed activities at the Harmony Platform would not result in 
permanent impacts to habitats used directly by marine mammals, but may 
have potential short-term impacts to food sources such as forage fish 
and invertebrates, and may affect acoustic habitat. There are no 
rookeries or major haul-out sites, no known foraging hot-spots, or 
other ocean bottom structure of significant biological importance to 
marine mammals present in the marine waters in the vicinity of the 
proposed action area. Therefore, the main impact issue associated with 
the proposed activity would be temporarily elevated sound levels and 
associated direct effects on marine mammals, as discussed previously in 
this document. The most likely impact to marine mammal habitat occurs 
from pile-driving effects on likely marine mammal prey near the Harmony 
Platform and minor impacts to the immediate substrate during conductor 
pipe installation.

Anticipated Effects on Potential Prey

    Common prey for cetaceans and pinnipeds in the proposed action area 
include a wide variety of nekton species spanning the water column 
pelagic, epipelagic, benthopelagic and demersal zones. The most common 
prey groups found in the area are hagfish, lampreys, cartilaginous, and 
bony fish (including anchovies), and large free swimming invertebrates 
(e.g., squids). Pinnipeds could also be considered prey for large 
cetaceans (e.g., killer whales). Prey for baleen whales (e.g., blue 
whale) include large zooplankton (e.g., krill), opportunistically 
consumed during migration/transit through the Santa Barbara Channel. 
Infaunal benthic amphipods exist in the proposed action area and are 
common prey items for feeding gray whales, but the Santa Barbara 
Channel is not known as a feeding ground for this species.
    Fish react to sounds which are especially strong and/or 
intermittent low-frequency sounds. Short duration, sharp sounds can 
cause overt or subtle changes in fish behavior and local distribution. 
Hastings and Popper (2005) and Hastings (2009) identified several 
studies that suggest fish may relocate to avoid certain areas of sound 
energy. Additional studies have documented effects of pile-driving (or 
other types of sounds) on fish, although several are based on studies 
in support of large multi-year bridge construction projects (e.g., 
Scholik and Yan, 2001, 2002; Popper and Hastings, 2009). Sound pulses 
at received levels of 160 dB re 1 [mu]Pa may cause subtle changes in 
fish behavior. SPLs of 180 dB may cause noticeable changes in behavior 
(Pearson et al., 1992; Skalski et al., 1992). SPLs of sufficient 
strength have been known to cause injury to fish and fish mortality. 
The most likely impact to fish from pile-driving activities in the 
proposed action area would be temporary behavioral avoidance of the 
area. The duration of fish avoidance of this area after pile-driving 
stops is unknown, but a rapid return to normal recruitment, 
distribution, and behavior is anticipated. In general, impacts to 
marine mammal prey species are expected to be minor and temporary due 
to the short timeframe for the proposed activities. However, adverse 
impacts may occur to a few species of fish which may be present in the 
proposed action area.

Anticipated Effects on Potential Foraging Habitat

    The Harmony Platform has been in place for 20 years and the 
addition of six conductor pipes to the existing 51 conductor pipes 
within the platform structure would not produce a quantifiable impact 
to marine mammals to their existing habitat. The additional six 
conductor pipes are approved (permitted) as part of the original 
Development Production Plan for Harmony Platform.
    The area likely impacted by the project activities is relatively 
small compared to the available habitat in the Santa Barbara Channel 
waters. The likelihood for avoidance by potential prey (i.e., fish and 
invertebrates) of the immediate area due to the temporary loss of this 
foraging habitat is unknown, but a rapid return to normal recruitment, 
distribution, and behavior is anticipated. Any behavioral avoidance by 
fish of the disturbed area would still leave significantly large areas 
of prey and marine mammal foraging habitat in the nearby vicinity.
    Given the short hourly duration of sound associated with individual 
pile-driving activities and the relatively small areas being affected, 
pile-driving activities associated with the proposed action are not 
likely to have a permanent, adverse effect on any fish habitat, or 
populations of fish and invertebrate species. Therefore, pile-driving 
is not likely to have a permanent, adverse effect on marine mammal 
foraging habitat at the proposed action area. Furthermore, the area 
around Harmony Platform in the Santa Barbara Channel, is already 
altered by various shipping activities.

[[Page 36756]]

    There would be no measureable loss of existing marine mammal water 
column or benthic habitat resulting from the installation of six 
conductor pipes at Harmony Platform. The impacts associated with the 
proposed project are temporary and are not expected to have long term 
effects on marine mammals or marine mammal habitat. The primary impact 
of the activity on the local environment is from sound, above and below 
water surface to a depth of 366 m. The transitory nature of sound would 
not impact the habitat of the marine mammal populations. A secondary 
impact from the activity would be the temporary suspension of bottom 
sediment, resulting from the installation via hammer driving of six 26-
in diameter steel conductor pipes within the platform jacket structure. 
The small amount of suspended sediment would quickly disperse and 
resettle to the seafloor. No permanent impacts are expected to marine 
mammals. The impacts are temporary in nature and are associated with 
pile-driving and construction noise disturbance and would not require 
restoration. Site conditions are anticipated to be unchanged from 
existing conditions for marine mammals following project 
implementation.
    There is no potential for an oil spill from operations/activities 
associated with this project. Potential impacts from an oil spill from 
existing operations are addressed in an approved Oil Spill Response 
Plan on file with BOEM for the Santa Ynez Production Unit, including 
Harmony Platform. Any potential spill from the supply boats or 
helicopters are already included in the approved operation and plan.
    Based on the preceding discussion of potential types of impacts to 
marine mammal habitat, overall, NMFS anticipates that the proposed 
action is not expected to cause significant impacts on habitats used by 
the marine mammal species in the proposed action area or on the food 
sources that they utilize.

Proposed 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 has incorporated a suite of appropriate mitigation 
measures into its project description (see Section 11 of the IHA 
application).
    To reduce the potential for disturbance from acoustic stimuli 
associated with the proposed activities, ExxonMobil and/or its 
designees have proposed to implement the following mitigation measures 
for marine mammals:
    (1) Proposed buffer and exclusion zones around the sound source;
    (2) Hours of operation;
    (3) Shut-down procedures; and
    (4) Ramp-up procedures.
    Proposed Exclusion Zones--ExxonMobil uses radii to designate 
exclusion and buffer zones and to estimate take for marine mammals. 
Table 2 (presented earlier in this document) shows the distances at 
which one would 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.
    Based on the modeling, exclusion zones (for triggering a shut-down) 
for Level A harassment would 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 would 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 would 
be shut-down immediately. If marine mammals are present within the 
shut-down zone before impact pile-driving activities begin, start of 
operations would be delayed until the exclusion zones are clear for at 
least 30 minutes. If marine mammals appear in the shut-down zone during 
proposed pile-driving activities, the PSO would instruct the hammer 
operator to halt all operations in a safe, but immediate manner. Pile-
driving activities would 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 would be documented and reported by the PSO and 
NMFS would be contacted within 24 hours. A non-PSO safety spotter would 
also be assigned to the lower deck observation area. All personnel 
operating at the lower observation levels would be required to wear 
appropriate personal protective equipment.
    Hours of Operation--The proposed activities would be conducted on a 
continual 24-hour basis; therefore, some of the 2.5 to 3.3 hours of 
active impact pile-driving periods would be expected to occur during 
non-daylight hours. To facilitate visual monitoring during non-daylight 
hours, the exclusion zones would be illuminated to permit more 
effective viewing by the PSO. Lighting would 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 would extend out to 325 m (1,066.3 ft) from the 
conductor pipe, PSOs would be stationed on an upper deck of the Harmony 
Platform to monitor for marine mammals during the proposed pile-driving 
activities. During non-daylight hours, PSOs would utilize night-vision 
devices and other appropriate equipment to monitor marine mammals. If 
nighttime visual aids are insufficient, ExxonMobil proposes 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 would shut-down the operating 
hammer if a marine mammal is detected outside the exclusion zone, and 
the sound source would 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 would be shut-down 
immediately.
    Following a shut-down, ExxonMobil would not resume pile-driving 
activities until the marine mammal has cleared the exclusion zone. 
ExxonMobil would 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 would be conducted by qualified PSOs. Visual 
monitoring would be conducted continuously during active pile-driving 
activities. PSOs would not have any tasks other than visual monitoring 
and would conduct monitoring from the best

[[Page 36757]]

vantage point(s) practicable (e.g., on the Harmony Platform or other 
suitable location) that provides 360[ordm] visibility of the Level A 
harassment exclusion zones and Level B harassment buffer zone, as far 
as possible. The PSO would be in radio communication with the hammer 
operator during pile-driving activities, and would 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 would 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 would monitor the 
exclusion zone, and if marine mammals are sighted, a shut-down would 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 would not commence the ramp-up. ExxonMobil would 
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.
    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 proposed 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 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 would 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 proposed measures, as 
well as other measures considered by NMFS or recommended by the public, 
NMFS has preliminarily determined that the proposed 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.

Proposed 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 would 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 proposed 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 or from the peer review panel (see the ``Monitoring Plan Peer 
Review'' section later in this document).
    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

[[Page 36758]]

(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.

Proposed Monitoring

    ExxonMobil proposes to sponsor marine mammal monitoring during the 
proposed project, in order to implement the proposed mitigation 
measures that require real-time monitoring, and to satisfy the 
anticipated monitoring requirements of the IHA. ExxonMobil's proposed 
``Monitoring Plan'' is described below this section. ExxonMobil 
understand that this monitoring plan would be subject to review by NMFS 
and that refinements may be required. Two main types of monitoring 
would be performed for this proposed 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 would 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 would be used to revise buffer and exclusion zone 
boundaries to reflect actual conditions during proposed project 
activities. Data from visual monitoring would be used to validate take 
estimate calculations.

Acoustic Monitoring

    Acoustic monitoring using hydrophones and microphones would be 
conducted to obtain and validate modeled in-water and in-air sound 
levels during the proposed pile-driving activities. Each hydrophone 
(in-water) and microphone (in-air) would be calibrated following the 
manufacturer's recommendations prior to the start of the proposed 
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 would 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 would 
be provided with the hammer model and size, hammer energy settings, and 
projected blows per minute for the conductor pipe segments requiring 
hammer pile-driving. Background in-air and in-water sound levels would 
be measured at Harmony Platform in the absence of pile-driving 
activities to obtain an ambient noise level, and recorded over a 
frequency range of 10 Hz to 20 kHz. Ambient noise level measurements 
would be conducted before, during, and after the project. The measured 
in-air and in-water sound data would 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 
would be measured.
    In-Water Monitoring--Acoustic monitoring would be performed at a 
minimum of two fixed stations located at 10 m (32.8 ft) and 
approximately 325 m (1,066.3 ft) from the conductor pipe sound source. 
These distances represent the 180 dB and 160 dB (rms) modeled sound 
levels. The following general approach would be used to measure in-
water sound levels:
     Acoustic monitoring would be conducted over the entire 
pile-driving period for each conductor pipe, starting approximately 1 
hour prior to pile-driving through 1 hour after impact hammering has 
stopped. Pre- and post-hammer pile-driving data would be used to 
determine ambient/background noise levels.
     A stationary hydrophone system with the ability to measure 
and record sound pressure levels would be deployed at a minimum of two 
monitoring locations (stations). SPLs would 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 10+/-1 m and at 325+/-33 m from the conductor 
pipe 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 project. The equipment would 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 would 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 hammer pile-driving 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 would be increased/decreased accordingly, 
following NMFS notification, concurrence, and authorization.
    In-Air Monitoring--Reference measurements would 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 would 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 would 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 would 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.

Platform-Based Visual Monitoring

    PSOs would be based aboard the Harmony Platform and would watch for 
marine mammals near the platform during conductor pipe installation 
activities during daytime and nighttime pile-driving activities. Visual 
monitoring for marine mammals would be performed at a minimum during 
periods of active hammer pile-driving throughout the proposed project 
following general procedures in Baker et al. (2013). Monitoring by PSOs 
would begin at least 30 minutes before the start of impact hammer pile-
driving, continue through an estimated 2.5 to 3.3 hours of pile-
driving, and conclude 30

[[Page 36759]]

minutes after pile-driving stops (up to 4.3 hours of monitoring per a 
period of pile-driving). Five to 7 periods of impact hammer pile-
driving would be required for each conductor pipe. When feasible, PSOs 
would conduct observations during periods when the impact hammer pile-
driving is not operating for comparison of sighting rates and behavior 
with and without operations and between pile-driving periods. In 
addition to monitoring during pile-driving activities, baseline 
monitoring of marine mammals would be performed up to one week before 
and one week after conductor pipe installation, as well as selected 
periods in between impact hammer pile-driving activities.
    The exclusion zone would be monitored to prevent injury to marine 
mammal species. Based on PSO observations, the impact hammer pile-
driving would 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 would be 
developed to ensure compliance with the IHA for this proposed project.
    Methods--There would be a team of 3 PSOs based aboard Harmony 
Platform conducting monitoring during active hammer pile-driving 
periods. Visual observations would take place during active hammering 
periods which includes both daylight and nighttime operations. This 
monitoring would 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 
would be anticipated for each of the six conductors. It is possible 
that an impact hammer pile-driving session would take less than 3.3 
hours and that the ``rest interval'' for the visual monitors separating 
driving segments would 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 pile-driving activities for a single 
conductor pipe, PSOs may be transferred to shore to await the next 
active pile-driving phase.
    PSOs would 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 
would 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 would be stationed on an 
upper platform deck where they have a clear view of the monitoring 
area. They would be approximately 180 degrees apart and each would 
monitor approximately one-half of the corresponding buffer zone and 
beyond with binoculars and other appropriate equipment. For exclusion 
zone area, one PSO would 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 would be illuminated 
during nighttime observations. Visual aids may be used but would not be 
required, providing the PSO has a clear view of the sea surface with 
the naked eye. A non-PSO safety spotter would also be assigned to the 
lower deck observation area. The safety spotter would be available to 
deter errant California sea lions using NMFS-recommended methods (see 
below) (NMFS, 2008).
    All personnel operating on the Harmony Platform would 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 would be 
determined via the regular work risk assessment process, and would be 
presented in the associated monitoring plans for the project.
    Equipment for monitoring would 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 would be conducted by qualified PSOs 
defined in Baker et al. (2013) and approved by NMFS. PSOs dedicated to 
the proposed project would have no other activity-related tasks.

PSO Data and Documentation

    PSOs would 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 would be used to estimate 
numbers of animals potentially ``taken'' by harassment (as defined in 
the MMPA). They would 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 would also be made during pile-
driving activities as well as daytime periods from the Harmony Platform 
when the regular operations would be underway without pile-driving 
activities to collect baseline biological data.
    When a sighting is made, the following information about the 
sighting would 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) would 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 would be recorded in a standardized format.
    Results from the platform-based visual observations would 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 pile-
driving activities.
    5. Data on the behavior and movement patterns of marine mammals

[[Page 36760]]

seen at times with and without pile-driving activities.

Proposed Reporting

    ExxonMobil would 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 
proposed pile-driving activities that were conducted and sightings of 
marine mammals near the operations. The report submitted to NMFS would 
provide full documentation of methods, results, and interpretation 
pertaining to all monitoring. The 90-day report would summarize the 
dates and location of impact hammer pile-driving activities and all 
marine mammal sightings (i.e., dates, times, locations, activities, and 
associated seismic survey activities). The report would 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 pile-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 would 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 would be 
publicly available on the NMFS Web site at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha.
    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 would 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 ([email protected]). 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 would 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 by email to the West Coast Regional Stranding 
Coordinator ([email protected]). The report must include the 
same information identified in the paragraph above. Activities may 
continue while NMFS reviews the circumstances of the incident. NMFS 
would 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 would 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 by email to the West 
Coast Regional Stranding Coordinator ([email protected]), within 
24 hours of discovery. ExxonMobil would 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].

[[Page 36761]]



Table 4--NMFS's Current Underwater and In-Air Acoustic Exposure Criteria
------------------------------------------------------------------------
          Criterion           Criterion definition        Threshold
------------------------------------------------------------------------
                     Impulsive (Non-Explosive) Sound
------------------------------------------------------------------------
Level A harassment (injury).  Permanent threshold   180 dB re 1
                               shift (PTS) (Any      [micro]Pa-m (root
                               level above that      means square [rms])
                               which is known to     (cetaceans)
                               cause TTS).          190 dB re 1
                                                     [micro]Pa-m (rms)
                                                     (pinnipeds).
Level B harassment..........  Behavioral            160 dB re 1
                               disruption (for       [micro]Pa-m (rms).
                               impulsive noise).
Level B harassment..........  Behavioral            120 dB re 1
                               disruption (for       [micro]Pa-m (rms).
                               continuous noise).
------------------------------------------------------------------------
                              In-Air Sound
------------------------------------------------------------------------
Level A harassment..........  NA..................  NA.
Level B harassment..........  Behavioral            90 dB re 20
                               disruption.           [micro]Pa (harbor
                                                     seals).
                                                    100 dB re 20
                                                     [micro]Pa (all
                                                     other pinniped
                                                     species).
                                                    NA (cetaceans).
------------------------------------------------------------------------

    Level B harassment is anticipated and proposed to be authorized as 
a result of the proposed 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 pile-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 would minimize any potential risk for injury, 
serious injury, or mortality.
    The following sections describe ExxonMobil's methods to estimate 
take by incidental harassment and present the applicant's estimates of 
the numbers of marine mammals that could be affected during the 
proposed 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) pile-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 proposed 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 proposed 
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 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\) proposed action area in the Santa Barbara 
Channel. The proposed 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 
proposed 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.

[[Page 36762]]



    Table 5--Estimated Densities and Possible Number of Marine Mammal Species That Might Be Exposed to Greater Than or Equal to 160 dB (Pile-Driving
           Activities) During ExxonMobil's Proposed Conductor Pipe Installation Activities in the Santa Barbara Channel Offshore of California
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Calculated take
                                                                 from pile-
                                                Calculated         driving
                                              take from pile-  activities in-
                                                  driving        air (i.e.,
                                              activities in-  estimated number                                          Approximate
                                  Density in   water (i.e.,    of  individuals   Total requested                       percentage of
            Species              action area     estimated    exposed to sound        take           Abundance \5\      population/    Population trend
                                  (/    number of     levels >=90 dB   authorization\4\                           stock              \5\
                                  km\2\) \1\    individuals   re 20 [mu]Pa for                                         estimate \6\
                                                exposed to    harbor seals and
                                               sound levels      90 dB re 20
                                               >=160 dB re 1   [mu]Pa for all
                                                [mu]Pa) \2\   other pinnipeds)
                                                                     \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
    North Pacific right whale..           NA               0                 0                 0  NA (18 to 21)--                 NA  NA.
                                                                                                   Eastern North
                                                                                                   Pacific stock.
    Gray whale.................       0.5067           0.693                 0                10  19,126 (18,107)--             0.05  Increasing over
                                                                                                   Eastern North                       past several
                                                                                                   Pacific stock.                      decades--Eastern
                                                                                                  155 (142)--Western                   North Pacific
                                                                                                   North Pacific                       stock.
                                                                                                   population.
    Humpback whale.............       0.0055           0.007                 0                 1  1,918 (1,876)--CA/            0.05  Increasing.
                                                                                                   OR/WA stock.
    Minke whale................         0.04           0.055                 0                 1  478 (202)--CA/OR/              0.2  NA.
                                                                                                   WA stock.
    Bryde's whale..............           NA               0                 0                 0  NA................              NA  NA.
    Sei whale..................         0.01           0.014                 0                 1  126 (83)--Eastern              0.8  NA.
                                                                                                   North Pacific
                                                                                                   stock.
    Fin whale..................        0.004           0.005                 0                 1  3,051 (2,598)--CA/            0.03  Increasing.
                                                                                                   OR/WA stock.
    Blue whale.................        0.008           0.011                 0                 1  1,647 (1,551)--               0.06  NA.
                                                                                                   Eastern North
                                                                                                   Pacific stock.
Odontocetes:
    Sperm whale................         0.08           0.109                 0                 1  971 (751)--CA/OR/              0.1  NA.
                                                                                                   WA stock.
    Pygmy sperm whale..........         0.05           0.068                 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.......         0.07           0.096                 0                 1  847 (466)--CA/OR/             0.12  NA.
                                                                                                   WA stock.
    Cuvier's beaked whale......         0.17           0.233                 0                 1  6,950 (4,481)--CA/            0.01  Declining off CA/
                                                                                                   OR/WA stock.                        OR/WA.
    Mesoplodon beaked whale....         0.08           0.109                 0                 1  694 (389)--CA/OR/             0.14  Declining off CA/
                                                                                                   WA stock.                           OR/WA.
    Killer whale...............         0.05           0.068                 0                 1  240 (162)--Eastern  0.42/0.29/0.28  NA--Eastern North
                                                                                                   North Pacific                       Pacific Offshore
                                                                                                   stock.                              stock; NA--
                                                                                                  346 (346)--Eastern                   Eastern North
                                                                                                   North Pacific                       Pacific Transient
                                                                                                   Transient stock.                    stock;
                                                                                                  354 (354)--West                      Increasing--West
                                                                                                   Coast Transient                     Coast Transient
                                                                                                   stock.                              stock.
    Short-finned pilot whale...         0.06           0.082                 0                 1  760 (465)--CA/OR/             0.13  NA.
                                                                                                   WA stock.
    Bottlenose dolphin.........         0.11           0.151                 0                10  1,006 (684)--CA/OR/            0.1  NA--CA/OR/WA
                                                                                                   WA stock.                           Offshore stock;
                                                                                                                                       NA--CA Coastal
                                                                                                                                       stock.
    Striped dolphin............         0.87           1.191                 0                20  10,908 (8,231)--CA/           0.18  NA.
                                                                                                   OR/WA stock.
    Short-beaked common dolphin        32.65          44.691                 0                45  411,211 (343,990)--           0.01  Varies with
                                                                                                   CA/OR/WA stock.                     oceanographic
                                                                                                                                       conditions.
    Long-beaked common dolphin.          8.5          11.635                 0               120  107,016 (76,224)--            0.11  Increasing over
                                                                                                   CA stock.                           last 30 years.
    Pacific white-sided dolphin         2.14           2.929                 0                30  26,930 (21,406)--             0.11  NA.
                                                                                                   CA/OR/WA stock.
    Northern right whale                0.66           0.903                 0                 1  8,334 (6,019)--CA/            0.01  NA.
     dolphin.                                                                                      OR/WA stock.
    Risso's dolphin............          0.5           0.684                 0                10  6,272 (4,913)--CA/            0.16  NA.
                                                                                                   OR/WA stock.
    Dall's porpoise............         3.34           4.572                 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          32.249                 0                33  296,750 (153,337)--           0.01  Increasing.
                                                                                                   U.S. stock.

[[Page 36763]]

 
    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           3.285             0.011                 4  30,196 (26,667)--             0.01  Increased 1981 to
                                                                                                   CA stock.                           2004.
    Northern elephant seal.....         9.85          13.483                 0                14  124,000 (74,913)--            0.01  Increasing through
                                                                                                   CA breeding stock.                  2005.
    Northern fur seal..........         0.79           1.081                 0                 2  12,844 (6,722)--              0.02  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\ Proposed action area (12,593 km\2\) in the Santa Barbara Channel off the coast of California.
\2\ Calculated take is the estimated number of animals in the in-water ensonified buffer zone multiplied by the number of days.
\3\ Calculated take is the estimated number of animals in the in-air ensonified buffer zone multiplied by the number of days.
\4\ Requested Take Authorization includes calculated takes for animals in the ensonified in-water and in-air buffer zones.
\5\ NMFS Marine Mammal Stock Assessment Reports.
\6\ Total requested (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 proposed 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 [micro]Pa 
(rms) and in-air sounds with received levels greater than or equal to 
90 dB re 20 [micro]Pa (rms) (for harbor seals)/100 dB re 20 [micro]Pa 
(rms) (for all other pinniped species) for impact hammer pile-driving 
activities on one or more occasions by considering the total marine 
area that would 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 pile-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 
would 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 pile-driving activities. The in-water 160 dB and in-air 90 dB 
(harbor seal)/100 dB (for all other pinniped species) radii are based 
on acoustic modeling data for the impact hammer pile-driving activities 
that may be used during the proposed action (see of the addendum to the 
IHA application). It is unlikely that a particular animal would stay in 
the area during the entire impact hammer pile-driving activities.
    The number of different individuals potentially exposed to received 
levels greater than or equal to 160 dB re 1 [micro]Pa (rms) for in-
water noise and 90 dB re 20 [micro]Pa (rms) (for harbor seals)/100 dB 
re 20 [micro]Pa (rms) (for all other pinniped species) for in-air noise 
from impact hammer pile-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.
    Applying the approach described above, approximately 0.3318 km\2\ 
would be ensonified within the in-water 160 dB isopleth and 
approximately 0.0053 km\2\/0.0475 km\2\ would be ensonified within the 
in-air 90 dB (harbor seals)/100 dB (for all other pinniped species) 
isopleths for impact hammer pile-driving activities (assuming 
omnidirectional spreading of sound from the conductor pipe) during the 
proposed conductor pipe installation activities. The take calculations 
within the proposed action area account for animals in the initial 
density snapshot and account for new (i.e., turnover) or previously 
exposed animals over an approximate 4-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 pile-driving activities; however, studies suggest that many 
marine mammals would avoid exposing themselves to sounds at these 
level, which suggests that there would not necessarily be a large 
number of new animals entering the proposed action area once the 
conductor pipe installation activities started. Also, the approach 
assumes that no cetaceans or pinnipeds would move away or toward the 
Harmony Platform. The take estimates represent the number of 
individuals that are expected (in absence of a conductor pipe 
installation activities) to occur over an approximate 4-day period of 
time in the waters that would 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 pile-driving activities.
    ExxonMobil's estimates of exposures to various sound levels assume 
that the proposed activities would 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 [micro]Pa (rms) (for harbor 
seals)/100

[[Page 36764]]

dB re 20 [micro]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 proposed activities.
    Table 5 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 requested. The total requested take authorization 
is given in the fifth column of Table 5.

Encouraging and Coordinating Research

    ExxonMobil would coordinate the planned marine mammal monitoring 
program associated with the proposed conductor pipe installation 
activities with researchers and other parties that express interest in 
this activity, area, and anthropogenic sound effects on marine mammals. 
ExxonMobil would coordinate with applicable U.S. agencies (e.g., NMFS), 
and would 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 would 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 would not have an 
unmitigable adverse impact on the availability of such species or 
stocks for taking for subsistence purposes.

Analysis and Preliminary 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 would likely be avoided through the implementation 
of the required monitoring and mitigation (i.e., shut-down) measures;
    (3) The fact that cetaceans and pinnipeds would have to be closer 
than 10 m and 3.5 m, respectively, during impact hammer pile-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 
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 proposed to be authorized by NMFS. Table 5 of 
this document outlines the number of requested 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 [micro]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 [micro]Pa for habor 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 determined Level A harassment 
thresholds for marine mammals for in-air noise.
    As mentioned previously, NMFS estimates that 30 species of marine 
mammals under its jurisdiction could be potentially affected by Level B

[[Page 36765]]

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 3 and 5 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 proposed 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 proposal to implement 
mitigation, monitoring, and reporting measures to minimize impacts to 
marine mammals. Additionally, the proposed conductor pipe installation 
activities would not adversely impact marine mammal habitat.
    For the marine mammal species that may occur within the proposed 
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 proposed 
pile-driving activities as the use of the impact hammer would occur 
over 30 intermittent intervals of 2.5 to 3.3 hours each for a combined 
total of about 4 days spread out over a 91-day period. Additionally, 
the conductor pipe installation activities would 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 36 marine mammal species under NMFS jurisdiction that may or 
are known to likely to occur in the proposed action area, seven are 
listed as threatened or endangered under the ESA: North Pacific right, 
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 pile-
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 preliminarily determined, provided that the aforementioned 
mitigation and monitoring measures are implemented, the impact of 
conducting pile-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 proposed conductor pipe 
installation activities. While behavioral modifications, including 
temporarily vacating the area during the impact hammer pile-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 
preliminary determine that the taking by Level B harassment from the 
specified activity would have a negligible impact on the affected 
species in the specified geographic region. NMFS believes that the 
length of the conductor pipe installation activities (duration of 
approximately 4 days total), the requirement to implement mitigation 
measures (e.g., shut-down of impact hammer pile-driving activities), 
and the inclusion of the monitoring and reporting measures, would 
reduce the amount and severity of the potential impacts from the 
activity to the degree that it would have a negligible impact on the 
species or stocks in the proposed 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 proposed monitoring and mitigation measures, NMFS 
preliminarily finds that the total marine mammal take from ExxonMobil's 
proposed conductor pipe installation activities would 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 pile-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 [micro]Pa 
for harbor seals and at or above 100 dB re 20 [micro]Pa for all other 
pinniped species for in-air sound levels during the proposed conductor 
pipe installation activities is in Table 5 of this document.
    In total, 10 gray, 1 humpback, 1 minke, 1 sei, 1 fin, 1 blue, and 1 
sperm whale could be taken by Level B harassment during the proposed 
seismic survey, which would represent 0.05, 0.05, 0.2, 0.8, 0.03, 0.06, 
and 0.1% 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, 1 Baird's beaked, 1 Cuvier's beaked 1 
Mesoplodon spp. Beaked, 1 killer, and 1 short-finned pilot whale, 10 
bottlenose, 20 striped, 45 short-beaked common, 120 long-beaked common, 
20 Pacific white-sided, 1 northern right whale, and 10 Risso's dolphin 
as well as 50 Dall's porpoise, which would represent 0.17, 0.12, 0.01, 
0.14, 0.42/0.29/0.28, 0.13, 0.1, 0.18, 0.01, 0.11, 0.11, 0.01, 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 33, 4, 14, and 2 individuals, which 
would represent 0.01, 0.01, 0.01, and 0.02% of the affected stock 
populations, respectively.
    NMFS has preliminary determined that the requested take estimates 
represent small numbers relative to the affected species or stocks 
sizes (i.e., all are less than 1%). 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 
preliminarily finds that small numbers of marine mammals would be taken 
relative to the populations of the affected species or stocks. See 
Table 5 for the requested authorized take numbers of marine mammals.

Endangered Species Act

    Of the species of marine mammals that may occur in the proposed 
action area, several are listed as threatened or endangered under the 
ESA, including the North Pacific right, humpback, sei, fin, blue, and 
sperm whale and

[[Page 36766]]

Guadalupe fur seal. ExxonMobil did not request take of endangered North 
Pacific right whales or the Guadalupe fur seals due to the low 
likelihood of encountering this species during the proposed pile-
driving activities. NMFS's Office of Protected Resources, Permits and 
Conservation Division, has 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 and, if 
appropriate, authorizing incidental take. NMFS would conclude formal 
section 7 consultation prior to making a determination on whether or 
not to issue the IHA. If the IHA is issued, ExxonMobil, in addition to 
the mitigation and monitoring requirements included in the IHA, would 
be required to comply with the Terms and Conditions of the Incidental 
Take Statement corresponding to NMFS's Biological Opinion issued to 
both ExxonMobil and NMFS's Office of Protected Resources.

National Environmental Policy Act

    To meet National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et 
seq.) requirements, NMFS will conduct a NEPA analysis to evaluate the 
effects of authorizing the proposed take of marine mammals prior to 
making a final determination on the issuance of the IHA. This notice, 
and referenced documents, including the IHA application provide the 
environmental issues and information relevant to the proposed conductor 
pipe installation activities as well as those specific to NMFS's 
issuance of the IHA. NMFS's NEPA analysis will be completed prior to 
the issuance or denial of this proposed IHA.

Proposed Authorization

    As a result of these preliminary determinations, NMFS propose to 
issue an IHA to ExxonMobil for conducting the pipe installation 
activities at the Harmony Platform in the Santa Barbara Channel 
offshore of California, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated. The proposed 
IHA language is provided below:
    ExxonMobil Production Company, P.O. Box 4358, Houston, Texas 77210-
4358, is hereby authorized under section 101(a)(5)(D) of the Marine 
Mammal Protection Act (MMPA) (16 U.S.C. 1371(a)(5)(D)), to harass small 
numbers of marine mammals incidental to conducting conductor pipe 
installation activities at the Harmony Platform in the Santa Barbara 
Channel off the coast of California:
    1. This Authorization is valid from August 15, 2014 through August 
14, 2015.
    2. This Authorization is valid only for ExxonMobil's activities 
associated with conductor pipe installation activities that shall occur 
in the following specified geographic area:
    In the Santa Barbara Channel offshore of California, the Harmony 
Platform is located at 34[deg]22'35.906'' North, 120[deg]10'04.486'' 
West. The water depth at the action area is 366 m on the continental 
slope below a relatively steep descent, and 4.7 km from the shelf 
break. The conductor pipe installation activities would be conducted 10 
km off the California coast, between Point Conception and the city of 
Santa Barbara, in the U.S. Exclusive Economic Zone, as specified in 
ExxonMobil's Incidental Harassment Authorization application and 
addendum.

3. Species Authorized and Level of Takes

    (a) The incidental taking of marine mammals, by Level B harassment 
only, is limited to the following species in the waters of the Pacific 
Ocean off the coast of California:
    (i) Mysticetes--see Table 5 (above) for authorized species and take 
numbers.
    (ii) Odontocetes--see Table 5 (above) for authorized species and 
take numbers.
    (iii) Pinnipeds--see Table 5 (above) for authorized species and 
take numbers.
    (iv) If any marine mammal species is encountered during pile-
driving activities that is not listed in Table 2 (attached) for 
authorized taking and is likely to be exposed to sound pressure levels 
(SPLs) greater than or equal to 160 dB re 1 [mu]Pa (rms) for impulse 
underwater noise from impact hammer pile-driving and/or at or above 100 
dB re 20 [mu]Pa (rms) for all pinnipeds species except harbor seals 
(which is at or above 90 dB re 20 [mu]Pa (rms) for in-air noise, then 
ExxonMobil must shut-down the operations to avoid take.
    (b) The taking by injury (Level A harassment), serious injury, or 
death of any of the species listed in Condition 3(a) above and the 
taking of any kind of any other species of marine mammal is prohibited 
and may result in the modification, suspension or revocation of this 
IHA.
    4. The methods authorized for taking by Level B harassment are 
limited to the following acoustic sources without an amendment to this 
IHA:
    (a) Pile-driving using impact hammer (i.e., installation);
    5. The taking of any marine mammal in a manner prohibited under 
this Authorization must be reported immediately to the Office of 
Protected Resources, National Marine Fisheries Service (NMFS), at 301-
427-8401.

6. Mitigation and Monitoring Requirements

    ExxonMobil is required to implement the following mitigation and 
monitoring requirements when conducting the specified activities to 
achieve the least practicable impact on affected marine mammal species 
or stocks:
    (a) Establish a 160 dB re 1 [mu]Pa (rms) buffer zone for cetaceans 
and pinnipeds and a 180 dB re 1 [mu]Pa (rms) exclusion zone for 
cetaceans and a 190 dB re 1 [mu]Pa (rms) exclusion zone for pinnipeds 
for in-water sounds before the conductor pipe installation activities 
begin so that underwater sounds associated with operations no longer 
exceed levels that are potentially harmful to marine mammals. See Table 
2 (above) for distances and buffer and exclusion zones.
    (b) Utilize three, NMFS-qualified, vessel-based Protected Species 
Observer (PSO) to visually watch for and monitor marine mammals near 
the impact hammer source during daytime and nighttime pile-driving 
activities. The Harmony Platform's crew shall also assist in detecting 
marine mammals, when practicable. PSOs shall be stationed at the best 
practicable vantage point(s) (on the lower platform level, and upper 
platform level) of the Harmony Platform to monitor the applicable 
buffer and exclusion zone for marine mammals during the conductor pipe 
installation activities. For the buffer zone, two PSOs shall be 
stationed on the upper platform level. For the exclusion zone, one PSO 
shall be concurrently stationed on the lower platform level. The lower 
platform level shall be illuminated during nighttime visual 
observations. PSOs shall have access to reticle binoculars (7 x 50 
Fujinon) and night-vision devices. PSO shifts shall last no longer than 
5 hours at a time. PSOs shall also make observations during daytime 
periods when the pile-driving activities are not occurring for 
comparison of animal abundance and behavior, when feasible. In addition 
to monitoring during pile-driving activities, baseline monitoring for 
marine mammals shall be performed up to one week before and one week 
after conductor pipe installation activities, as well as selected 
periods in between impact hammer pile-driving activities.

[[Page 36767]]

    (c) A PSO shall record the following information when a marine 
mammal is sighted:
    (i) 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 conductor pipe installation activities (e.g., none, 
avoidance, approach, paralleling, etc., and including responses to 
ramp-up), speed of travel, and duration of presence; and
    (ii) Date, time, location, activity of the conductor pipe 
installation activities (including whether in state of ramp-up or shut-
down), monitoring and mitigation measures implemented (or not 
implemented), weather conditions, Beaufort sea state and wind force, 
visibility, and sun glare; and
    (iii) The data listed under Condition 6(c)(ii) shall 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.
    (iv.) If inclement weather conditions (i.e., fog, rain, or rough 
Beaufort sea state) limits or impairs the PSO's visibility of the 
water's surface to less than 30.5 m (100 ft) within the action area, 
then all noise-generating conductor pipe installation activities shall 
be stopped until visibility improves.
    (d) Visually observe the entire extent of the in-water buffer zone 
(160 dB re 1 [mu]Pa [rms]) for cetaceans and pinnipeds and in-water 
exclusion zone (180 dB re 1 [mu]Pa [rms] for cetaceans and 190 dB re 1 
[mu]Pa [rms] for pinnipeds as well as the in-air buffer zone for harbor 
seals (90 dB re 20 [mu]Pa) and for all other pinnipeds (100 dB re 20 
[mu]Pa); see Table 2 [above] for distances) using NMFS-qualified PSOs, 
for at least 30 minutes prior to starting the impact hammer (day or 
night). If the PSO finds a marine mammal within the exclusion zone, 
ExxonMobil must delay the pile-driving activities until the marine 
mammal(s) has left the area. If the PSO sees a marine mammal that 
surfaces, then dives below the surface, the PSO shall wait 30 minutes. 
If the PSO sees no marine mammals during that time, they should assume 
that the animal has moved beyond the exclusion zone. If for any reason 
the entire exclusion zone radius cannot be seen for the entire 30 
minutes (i.e., rough seas, fog, darkness), or if marine mammals are 
near, approaching, or in the exclusion zone, the impact hammer may not 
be ramped-up.
    (e) Implement a ``ramp-up'' procedure when starting up at the 
beginning of pile-driving activities, which means starting with 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. During ramp-up, the PSOs shall monitor the exclusion zone, 
and if marine mammals are sighted, a shut-down shall be implemented. 
Therefore, initiation of ramp-up procedures from shut-down requires 
that the PSOs be able to view the full exclusion zone as described in 
Condition 6(a) (above).
    (f) Shut-down the pile-driving activities if a marine mammal is 
detected approaching, about to enter, or located within the relevant 
exclusion zone (as defined in Table 2, above). A shut-down means all 
operating impact hammers are shut-down (i.e., turned off). If any 
marine mammal is sighted within the relevant exclusion zone prior to 
pile-driving activities, the hammer operator (or other authorized 
individual) shall delay conductor pipe installation activities until 
the animal has moved outside the exclusion zone or the animal is not 
resighted within for 15 minutes for species with shorter dive durations 
(small odontocetes and pinnipeds) or 30 minutes for species with longer 
dive durations (mysticetes and large odontocetes, including sperm, 
pygmy and dwarf sperm, killer, and beaked whales).
    (g) Following a shut-down, the conductor pipe installation 
activities shall not resume until the PSO has visually observed the 
marine mammal(s) exiting the exclusion zone and is not likely to 
return, or has not been seen within the exclusion zone for 15 minutes 
for species with shorter dive durations (small odontocetes and 
pinnipeds) or 30 minutes for species with longer dive durations 
(mysticetes and large odontocetes, including sperm, pygmy and dwarf 
sperm, killer, and beaked whales).
    (h) Following a shut-down and subsequent animal departure, 
conductor pipe installation activities may resume following ramp-up 
procedures described in Condition 6(e).
    (i) To facilitate visual monitoring during non-daylight hours, the 
exclusion zones shall be illuminated by lights to allow for more 
effective viewing of the area by the PSO on-duty.
    (j) In-Water Monitoring--Acoustic monitoring shall be performed at 
a minimum of two fixed stations located at 10 m and approximately 325 m 
from the conductor pipe sound source. The following general approach 
shall be used to measure in-water sound levels:
    (k) Acoustic monitoring shall be conducted over the entire pile-
driving period for each conductor pipe, starting approximately 1 hour 
prior to pile-driving through 1 hour after impact hammering has 
stopped. Pre- and post-hammer pile-driving data shall be used to 
determine ambient/background noise levels.
    (i) A stationary hydrophone system with the ability to measure and 
record sound pressure levels (SPL) shall be deployed at a minimum of 
two monitoring locations. SPLs shall be recorded in voltage, converted 
to microPascals ([mu]Pa), and post-processed to decibels (dB [re 1 
[mu]Pa]). For the first conductor pipe installation, hydrophones shall 
be placed at 101 m and at 32533 m from the 
conductor pipe at depths ranging from 10 to 30 m below the water 
surface to avoid potential interferences for surface water energy, and 
to target the depth range of maximum occurrence of marine mammal most 
likely in the area during the project. If necessary, additional 
hydrophone mooring systems shall 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.
    (ii) At a minimum, the following sound data shall 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, and total number of 
strikes per continuous hammer pile-driving period for each conductor 
pipe.
    (iii) In the event that field measurements indicate different SPL 
(rms) values than those predicted by modeling for either the maximum 
distances of the buffer or exclusion zones from the sound source, 
corresponding boundaries for the buffer and exclusion zones shall be 
increased/decreased accordingly, following NMFS notification and 
concurrence.
    (l) In-Air Monitoring--Reference measurements shall be made 
approximately 10 to 20 m from the initial hammer strike position using 
a stationary microphone. The microphone shall be placed as far away 
from other large sound sources as practical. In-air sound levels shall 
be recorded at several points around the base of the Harmony Platform 
at sea level to validate modeled sound levels. Recorded data shall be 
recorded as dB (re 20 [mu]Pa) for comparison to in-air noise thresholds 
for Level B harassment for pinnipeds.

7. Reporting Requirements

    ExxonMobil is required to:

[[Page 36768]]

    (a) Submit a draft report on all activities and monitoring results 
to the Office of Protected Resources, NMFS, within 90 days of the 
completion of ExxonMobil's conductor pipe installation activities at 
the Harmony Platform in the Santa Barbara Channel off the coast of 
California. This report must contain and summarize the following 
information:
    (i) Dates, times, locations, weather, sea conditions (including 
Beaufort sea state and wind force), and associated activities during 
all conductor pipe installation activities and marine mammal sightings;
    (ii) Species, number, location, distance from the platform, and 
behavior of any marine mammals, as well as associated conductor pipe 
installation activities (e.g., number of ramp-ups and shut-downs), 
observed throughout all monitoring activities.
    (iii) An estimate of the number (by species) of marine mammals 
that: (A) Are known to have been exposed to the pile-driving activities 
(based on visual observation) at received levels greater than or equal 
to 160 dB re 1 [mu]Pa (rms), and/or 180 dB re 1 [mu]Pa (rms) for 
cetaceans and greater than or equal to 190 dB re 1 [mu]Pa (rms) for 
pinnipeds with a discussion of any specific behaviors those individuals 
exhibited; and (B) may have been exposed (based on modeled values for 
the impact hammer) to the pile-driving activities at received levels 
greater than or equal to 160 dB re 1 [mu]Pa (rms), and/or 180 dB re 1 
[mu]Pa (rms) for cetaceans and greater than or equal to 190 dB re 1 
[mu]Pa (rms) for pinnipeds with a discussion of the nature of the 
probable consequences of that exposure on the individuals that have 
been exposed.
    (iv) A description of the implementation and effectiveness of the: 
(A) Terms and Conditions of the Biological Opinion's Incidental Take 
Statement (ITS) (attached); and (B) mitigation measures of the 
Incidental Harassment Authorization. For the Biological Opinion, the 
report shall confirm the implementation of each Term and Condition, as 
well as any conservation recommendations, and describe their 
effectiveness for minimizing the adverse effects of the action on 
Endangered Species Act-listed marine mammals.
    (l) Submit a final report to the Chief, Permits and Conservation 
Division, Office of Protected Resources, NMFS, within 30 days after 
receiving comments from NMFS on the draft report. If NMFS decides that 
the draft report needs no comments, the draft report shall be 
considered to be the final report.

8. 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 
Authorization, such as an injury (Level A harassment), serious injury 
or mortality (e.g., equipment interaction, and/or entanglement), 
ExxonMobil shall 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 ([email protected]). The report must include the 
following information:
    (a) Time, date, and location (latitude/longitude) of the incident; 
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 marine 
mammal observations in the 24 hours preceding the incident; species 
identification or description of the animal(s) involved; the fate of 
the animal(s); and photographs or video footage of the animal (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, 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 shall 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 by email to the West Coast Regional Stranding 
Coordinator ([email protected]). The report must include the 
same information identified in Condition 8(a) above. Activities may 
continue while NMFS reviews the circumstances of the incident. NMFS 
shall work with ExxonMobil to determine whether modifications in 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 
Condition 2 of this Authorization (e.g., previously wounded animal, 
carcass with moderate to advanced decomposition, or scavenger damage), 
ExxonMobil shall 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 by email to the West Coast Regional Stranding 
Coordinator ([email protected]), within 24 hours of the 
discovery. ExxonMobil shall 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.
    9. Endangered Species Act Biological Opinion and Incidental Take 
Statement ExxonMobil is required to comply with the Terms and 
Conditions of the ITS corresponding to NMFS's Biological Opinion issued 
to both ExxonMobil and NMFS's Office of Protected Resources (attached).
    10. A copy of this Authorization and the ITS must be in the 
possession of all contractors and PSO(s) operating under the authority 
of this Incidental Harassment Authorization.
    11. Penalties and Permit Sanctions--Any person who violates any 
provision of this IHA is subject to civil and criminal penalties, 
permit sanctions, and forfeiture as authorized under the MMPA.
    12. This IHA may be modified, suspended or withdrawn if ExxonMobil 
fails to abide by the conditions prescribed herein or if the authorized 
taking is having more than a negligible impact on the species or stock 
of affected marine mammals, or if there is an unmitigable adverse 
impact on the availability of such species or stocks for subsistence 
uses.
Request for Public Comments
    NMFS requests comments on our analysis, the draft authorization, 
and

[[Page 36769]]

any other aspect of the notice of proposed IHA for ExxonMobil's 
proposed installation of conductor pipes via hydraulic hammer driving 
at Harmony Platform, Santa Ynez Production Unit, located in the Santa 
Barbara Channel offshore of California. Please include with your 
comments any supporting data or literature citations to help inform our 
final decision on ExxonMobil's request for an MMPA authorization.
    Concurrent with the publication of this notice in the Federal 
Register, NMFS is forwarding copies of this application to the Marine 
Mammal Commission and its Committee of Scientific Advisors.

    Dated: June 25, 2014.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2014-15224 Filed 6-27-14; 8:45 am]
BILLING CODE 3510-22-P