[Federal Register Volume 82, Number 226 (Monday, November 27, 2017)]
[Notices]
[Pages 56120-56149]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-25516]



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Vol. 82

Monday,

No. 226

November 27, 2017

Part II





 Department of Commerce





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National Oceanic and Atmospheric Administration





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Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to a Marine Geophysical Survey in the 
Southwest Pacific Ocean, 2017/2018; Notice

  Federal Register / Vol. 82 , No. 226 / Monday, November 27, 2017 / 
Notices  

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XF456


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Marine Geophysical Survey in the 
Southwest Pacific Ocean, 2017/2018

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

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
Lamont-Doherty Earth Observatory of Columbia University (L-DEO) to 
incidentally harass, by Level A and Level B harassment only, marine 
mammals during marine geophysical survey activities in the southwest 
Pacific Ocean.

DATES: This Authorization is valid from October 27, 2017 through 
October 26, 2018.

FOR FURTHER INFORMATION CONTACT: Jordan Carduner, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: www.nmfs.noaa.gov/pr/permits/incidental/research.htm. In case of problems accessing these documents, 
please call the contact listed above.

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 (as delegated to NMFS) to allow, upon 
request, the incidental, but not intentional, taking of small numbers 
of marine mammals by U.S. 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 incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), 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 and 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.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, or kill, or attempt to harass, hunt, capture, or kill any 
marine mammal.
    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).

National Environmental Policy Act

    NMFS prepared an Environmental Assessment (EA) and analyzed the 
potential impacts to marine mammals that would result from L-DEO's 
planned surveys. A Finding of No Significant Impact (FONSI) was signed 
on October 27, 2017. A copy of the EA and FONSI is available upon 
request (see ADDRESSES).

Summary of Request

    On May 17, 2017, NMFS received a request from L-DEO for an IHA to 
take marine mammals incidental to conducting a marine geophysical 
survey in the southwest Pacific Ocean. On September 13, 2017, we deemed 
L-DEO's application for authorization to be adequate and complete. L-
DEO's request is for take of 38 species of marine mammals by Level B 
harassment and Level A harassment. Neither L-DEO nor NMFS expects 
mortality to result from this activity, and, therefore, an IHA is 
appropriate. The planned activity is not expected to exceed one year, 
hence, we do not expect subsequent MMPA incidental harassment 
authorizations would be issued for this particular activity.

Description of Activity

    Researchers from California State Polytechnic University, 
California Institute of Technology, Pennsylvania State University, 
University Southern California, University of Southern Mississippi, 
University of Hawaii at Manoa, University of Texas, and University of 
Wisconsin Madison, with funding from the U.S. National Science 
Foundation, propose to conduct three high-energy seismic surveys from 
the research vessel (R/V) Marcus G. Langseth (Langseth) in the waters 
of New Zealand in the southwest Pacific Ocean in 2017/2018. The NSF-
owned Langseth is operated by L-DEO. One proposed survey would occur 
east of North Island and would use an 18-airgun towed array with a 
total discharge volume of ~3,300 cubic inches (in\3\). Two other 
proposed seismic surveys (one off the east coast of North Island and 
one south of South Island) would use a 36-airgun towed array with a 
discharge volume of ~6,600 in\3\. The surveys would take place in water 
depths from ~50 to >5,000 m.
    The North Island two-dimensional (2-D) survey would consist of 
approximately 35 days of seismic operations plus approximately 2 days 
of transit and towed equipment deployment/retrieval. The Langseth would 
depart Auckland on approximately October 26, 2017 and arrive in 
Wellington on December 1, 2017. The North Island three-dimensional (3-
D) survey is proposed for approximately January 5, 2018-February 8, 
2018 and would consist of approximately 33 days of seismic operations 
plus approximately 2 days of transit and towed equipment deployment/
retrieval. The Langseth would leave and return to port in Napier. The 
South Island 2-D survey is proposed for approximately February 15, 
2018-March 15, 2018 and would consist of approximately 22 days of 
seismic operations, approximately 3 days of transit, and approximately 
7 days of ocean bottom seismometer (OBS) deployment/retrieval.
    The proposed surveys would occur within the Exclusive Economic Zone 
(EEZ) and territorial sea of New Zealand. The proposed North Island 2-D 
survey would occur within ~37-43[deg] S. between 180[deg] E. and the 
east coast of North Island along the Hikurangi margin. The proposed 
North Island 3-D survey would occur over a 15 x 60 kilometer (km) area 
offshore at the Hikurangi trench and forearc off North Island within 
~38-39.5[deg] S., ~178-179.5[deg] E. The proposed South Island 2-D 
survey would occur along the Puysegur margin off South Island within 
~163-168[deg] E. between 50[deg] S. and the south coast of South 
Island. Please see Figure 1 and Figure 2 in L-DEO's IHA application for 
maps depicting the

[[Page 56121]]

specified geographic region of the proposed surveys.
    A detailed description of the planned project is provided in the 
Federal Register notice for the proposed IHA (82 FR 45116; September 
27, 2017). Since that time, no changes have been made to the planned 
activities. Therefore, a detailed description is not provided here. 
Please refer to that Federal Register notice for the description of the 
specific activity. Specifications of the airgun arrays, trackline 
distances, and water depths of each of the three proposed surveys are 
shown in Table 1.

Table 1--Specifications of Airgun Arrays, Trackline Distances, and Water Depths Associated With Three Planned R/
                                       V Langseth Surveys off New Zealand
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                                       North Island 2-D survey  North Island 3-D survey  South Island 2-D survey
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Airgun array configuration and total   36 airguns, four         two separate 18-airgun   36 airguns, four
 volume.                                strings, total volume    arrays that would fire   strings, total volume
                                        of ~6,600 in\3\.         alternately; each        of ~6,600 in\3\.
                                                                 array would have a
                                                                 total discharge volume
                                                                 of ~3,300 in\3\.
Tow depth of arrays..................  9 m....................  9 m....................  9 m.
Shot point intervals.................  37.5 m.................  37.5 m *...............  50 m.
Source velocity (tow speed)..........  4.3 knots..............  4.5 knots..............  4.5 knots.
Water depths.........................  8%, 23%, and 69% of      0%, 42%, and 58% of      1%, 17%, and 82% of
                                        line km would take       line km would take       line km would take
                                        place in shallow (<100   place in shallow,        place in shallow,
                                        m), intermediate (100-   intermediate, and deep   intermediate, and deep
                                        1,000 m), and deep       water, respectively.     water, respectively.
                                        water (>1,000 m),
                                        respectively.
Approximate trackline distance.......  5,398 km...............  3,025 km...............  4,876 km.
Percentage of survey tracklines        Approximately 9 percent  Approximately 1 percent  Approximately 6
 proposed in New Zealand Territorial                                                      percent.
 Waters.
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* The two arrays fire alternately with an approximate distance of 37.5 m traveled between the firing of one
  array, then the other.

Comments and Responses

    NMFS published a notice of proposed IHA in the Federal Register on 
September 27, 2017 (82 FR 45116). During the 30-day public comment 
period, NMFS received comments from the Marine Mammal Commission 
(Commission), the Marine Seismic Research Oversight Committee (MSROC) 
and from members of the general public. NMFS has posted the comments 
online at: http://www.nmfs.noaa.gov/pr/permits/incidental. The 
following is a summary of the public comments and NMFS' responses.
    Comment 1: The Commission expressed concerns regarding L-DEO's 
method to estimate the extent of the Level A and B harassment zones and 
the numbers of marine mammal takes. The Commission stated that the 
model is not the best available science because it assumes spherical 
spreading, a constant sound speed, and no bottom interactions for 
surveys in deep water. In light of their concerns, the Commission 
recommended that NMFS require L-DEO to re-estimate the Level A and 
Level B harassment zones and associated takes of marine mammals using 
both operational (including number/type/spacing of airguns, tow depth, 
source level/operating pressure, operational volume) and site-specific 
environmental (including sound speed profiles, bathymetry, and sediment 
characteristics at a minimum) parameters.
    NMFS Response: NMFS understands the concerns expressed by the 
Commission about L-DEO's current modeling approach for estimating Level 
A and Level B harassment zones. L-DEO has conveyed to NMFS that 
additional modeling efforts to refine the process and conduct 
comparative analysis may be possible with the availability of research 
funds and other resources. Obtaining research funds is typically 
accomplished through a competitive process, including those submitted 
to U.S. Federal agencies. The use of models for calculating buffer and 
exclusion zone radii and for developing take estimates is not a 
requirement of the MMPA incidental take authorization process. 
Furthermore, NMFS does not provide specific guidance on model 
parameters nor prescribe a specific model for applicants as part of the 
MMPA incidental take authorization process at this time, although we do 
review methods to ensure their adequacy for prediction of take.
    L-DEO's application describes their approach to modeling Level A 
and Level B harassment zones. In summary, L-DEO acquired field 
measurements for several array configurations at shallow, intermediate, 
and deep-water depths during acoustic verification studies conducted in 
the northern Gulf of Mexico in 2007 and 2008; these were presented in 
Tolstoy et al. (2009). Based on the empirical data from those studies, 
L-DEO developed a sound propagation modeling approach that predicts 
received sound levels as a function of distance from a particular 
airgun array configuration in deep water (Diebold et al., 2010; NSF-
USGS 2011). For the planned surveys off the coast of New Zealand, L-DEO 
modeled Level A and Level B harassment zones using the sound 
propagation modeling approach described in Diebold et al. (2010), based 
on the empirically-derived measurements from the Gulf of Mexico 
calibration survey. For deep water (>1000 meters (m)), L-DEO used the 
deep-water radii obtained from model results down to a maximum water 
depth of 2,000 m (Figure 2 and 3 in Diebold et al., 2010); the radii 
for intermediate water depths (100-1,000 m) were derived from the deep-
water radii by applying a correction factor (multiplication) of 1.5 
(Fig. 16 in Diebold et al., 2010); the radii for shallow-water depths 
(<100 m) were derived by applying a scaling factor to the empirically 
derived measurements from the Gulf of Mexico calibration survey 
(Tolstoy et al., 2009) to account for the differences in tow depth 
between the Gulf of Mexico calibration survey (6 m) and the planned New 
Zealand surveys (9 and 12 m).
    In 2015, L-DEO explored the question of whether the Gulf of Mexico 
calibration data adequately informs the model to predict isopleths in 
other areas by conducting a retrospective sound power analysis of one 
of the lines acquired during a L-DEO seismic survey offshore New Jersey 
in 2014 (Crone, 2015). NMFS presented a comparison of the predicted 
radii (i.e.,

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modeled isopleths to distances corresponding to Level A and Level B 
harassment thresholds) with radii based on in situ measurements in a 
previous notice of issued Authorization for Lamont-Doherty (see 80 FR 
27635; May 14, 2015, Table 1).
    Briefly, Crone's (2015) analysis, specific to the survey site 
offshore New Jersey, confirmed that in-situ, site specific measurements 
and estimates of 160 decibels (dB) root mean square (rms) and 180 dB 
rms isopleths collected by the Langseth's hydrophone streamer in 
shallow water were smaller than the modeled (i.e., predicted) zones for 
two seismic surveys conducted offshore New Jersey in shallow water in 
2014 and 2015. In that particular case, Crone's (2015) results showed 
that L-DEO's modeled 180 dB rms and 160 dB rms zones were approximately 
28 percent and 33 percent larger, respectively, than the in-situ, site-
specific measurements, thus confirming that L-DEO's model was 
conservative in that case. The following is a summary of two additional 
analyses of in-situ data that support L-DEO's use of the modeled Level 
A and Level B harassment zones in this particular case.
    In 2010, L-DEO assessed the accuracy of their modeling approach by 
comparing the sound levels of the field measurements acquired in the 
Gulf of Mexico study to their model predictions (Diebold et al., 2010). 
They reported that the observed sound levels from the field 
measurements fell almost entirely below the predicted mitigation radii 
curve for deep water (greater than 1,000 m; 3280.8 feet (ft)) (Diebold 
et al., 2010).
    In 2012, L-DEO used a similar process to model distances to 
isopleths corresponding to the isopleths corresponding to Level A and 
Level B harassment thresholds for a shallow-water seismic survey in the 
northeast Pacific Ocean offshore Washington State. L-DEO conducted the 
shallow-water survey using the same airgun configuration planned for 
the surveys considered in this IHA (i.e., 6,600 cubic inches (in\3\)) 
and recorded the received sound levels on both the shelf and slope 
using the Langseth's 8 kilometer (km) hydrophone streamer. Crone et al. 
(2014) analyzed those received sound levels from the 2012 survey and 
confirmed that in-situ, site specific measurements and estimates of the 
160 dB rms and 180 dB rms isopleths collected by the Langseth's 
hydrophone streamer in shallow water were two to three times smaller 
than L-DEO's modeling approach had predicted. While the results 
confirmed bathymetry's role in sound propagation, Crone et al. (2014) 
were also able to confirm that the empirical measurements from the Gulf 
of Mexico calibration survey (the same measurements used to inform L-
DEO's modeling approach for the planned surveys in the southwest 
Pacific Ocean) overestimated the size of the predicted isopleths for 
the shallow-water 2012 survey off Washington State and were thus 
precautionary, in that particular case.
    NMFS continues to work with L-DEO to address the issue of 
incorporating site-specific information for future authorizations for 
seismic surveys. However, L-DEO's current modeling approach (supported 
by the three studies discussed previously) represents the best 
available information for NMFS to reach determinations for this IHA. As 
described earlier, the comparisons of L-DEO's model results and the 
field data collected in the Gulf of Mexico, offshore Washington State, 
and offshore New Jersey illustrate a degree of conservativeness built 
into L-DEO's model for deep water, which NMFS expects to offset some of 
the limitations of the model to capture the variability resulting from 
site-specific factors. Based upon the best available information (i.e., 
the three data points, two of which are peer-reviewed, discussed in 
this response), NMFS finds that the Level A and Level B harassment zone 
calculations are appropriate for use in this particular IHA. 
Additionally, results of acoustic modeling represent just one component 
of the analysis during the MMPA authorization process, as NMFS also 
takes into consideration other factors associated with the activity 
(e.g., geographic location, duration of activities, context, sound 
source intensity, etc.).
    Comment 2: The Commission recommended that NMFS use a different 
data source to estimate densities of New Zealand fur seals and southern 
elephant seals than was used in the proposed IHA. Specifically, the 
Commission recommended that NMFS rely on the data presented in the U.S. 
Navy Marine Species Density Database (NMSDD) to estimate take of these 
pinniped species. The Commission also recommended that NMFS convene an 
internal working group to determine what data sources are considered 
best available for the various species and in the various areas and 
provide that information to applicants accordingly.
    NMFS Response: Density data presented in Bonnell et al. (1992) was 
used in this particular IHA because it was based on systematic aerial 
at-sea surveys (off Oregon and Washington), whereas the data presented 
in NMSDD was derived from surveys of hauled out pinnipeds. While the 
NMSDD data is more recent than the data presented in Bonnell et al. 
(1992), in this case we determined that densities presented in Bonnell 
et al. (1992), which were derived from at-sea surveys, would be more 
representative of densities for similar taxonomic species in a 
different area (in this case, New Zealand). It is important to note 
that the NMSDD data are specific to the west coast of the U.S. and were 
based on population sizes for the species in the particular geographic 
ranges for the particular geographic areas of concern for the U.S. 
Navy, and are therefore useful in estimating densities for those same 
species in those same particular geographic areas. However, in this 
case the densities reported for pinnipeds off the U.S. west coast were 
used to estimate densities of surrogate species in a different 
geographic area (New Zealand). Thus our selection of the data from 
Bonnell et al. (1992) to extrapolate pinniped densities in New Zealand 
for this IHA was based on a preference to use data that was based on 
at-sea surveys to estimate at-sea density. While we acknowledge the 
usefulness of the NMSDD data for calculating marine mammal densities 
for ITAs for activities that occur on the U.S. west coast, that does 
not preclude us from relying on other data sources when activities are 
planned to occur outside the U.S. In summary, while NMFS has used NMSDD 
density data to estimate take of pinnipeds in previous ITAs for 
activities that occurred off the west coast of the U.S., NMFS 
determined that, for this particular IHA, Bonnell et al. (1992) 
represented the best available information for the marine mammals in 
the survey area.
    Regarding the Commission's recommendation that NMFS convene an 
internal working group to determine what data sources are considered 
best available for the various species and in the various areas, NMFS 
may consider future action to address these issues, but currently 
intends to address these questions through ongoing interactions with 
the U.S. Navy, academic institutions, and other organizations.
    Comment 3: The Commission recommended that NMFS adjust density 
estimates using some measure of uncertainty (i.e., coefficient of 
variation, standard deviation, standard error) rather than the proposed 
25 percent contingency, and recommended that NMFS convene a working 
group to determine how best to incorporate uncertainty in density data 
that are extrapolated.
    NMFS Response: The Commission has recommended previously that NMFS

[[Page 56123]]

adjust density estimates using some measure of uncertainty when 
available density data originate from different geographic areas, 
temporal scales, and species, especially for actions which will occur 
outside the U.S. EEZ where site- and species-specific density estimates 
tend to be scant, such as L-DEO's planned survey. We have attempted to 
do so in this IHA, and feel the 25 percent correction factor is an 
appropriate method in this case to account for uncertainties in the 
density data that was available for use in the take estimates. NMFS is 
open to consideration of other correction factors for use in future 
IHAs and looks forward to further discussion with the Commission on how 
best to incorporate uncertainty in density estimates in instances where 
density data is limited.
    Regarding the recommendation that NMFS convene a working group to 
determine how best to incorporate uncertainty in density data that are 
extrapolated, NMFS may consider future action to address these issues, 
but currently intends to address these questions through ongoing 
interactions with the U.S. Navy, academic institutions, and other 
organizations.
    Comment 4: The Commission expressed concern regarding methods used 
to estimate the numbers of takes, including the use of rounding in 
calculations and recommended that NMFS share the rounding criteria with 
the Commission.
    NMFS Response: NMFS appreciates the Commission's ongoing concern in 
this matter. Calculating predicted takes is not an exact science and 
there are arguments for taking different mathematical approaches in 
different situations, and for making qualitative adjustments in other 
situations. We believe, however, that the methodology used for take 
calculation in this IHA, as described in detail in the Federal Register 
notice of the proposed IHA (82 FR 45116; September 27, 2017), remains 
appropriate. NMFS continues to refine the rounding criteria and will 
share the criteria with the Commission upon its finalization.
    Comment 5: The Commission recommended that NMFS authorize Level A 
take based on group size of the species when Level A take is 
anticipated and when the estimated Level A take of a species was less 
than the group size for the species.
    NMFS Response: NMFS considered this recommendation but ultimately 
concluded that, given the modeled Level A harassment zones in concert 
with the mitigation measures required in the IHA, it was not realistic 
to assume a single take by Level A harassment of an individual animal 
would translate to an entire group of that species being taken by Level 
A harassment, in all instances. The assumption that if a single 
individual is taken then an entire group would be taken only applies in 
the case of instantaneous exposure, as it is extremely unlikely than an 
entire group of animals would remain within an area long enough to be 
taken by an accumulation of energy (SELcum). Therefore, in 
analyzing this question, we only considered the potential for Level A 
take of an entire group of the species in the context of peak sound 
pressure level (SPL). The modeled Level A zones (peak SPL) for marine 
mammal functional hearing groups are relatively small, especially in 
the cases of low-frequency cetaceans, mid-frequency cetaceans, phocid 
pinnipeds and otariid pinnipeds, for which the modeled Level A zones 
(peak SPL) are all estimated to be less than 50 m (Tables 6, 7 and 8). 
Coupled with the fact that shutdown of the airguns is required for 
marine mammals within 100 m of the array (with the exception of short-
beaked common dolphins, dusky dolphins and southern right whale 
dolphins that approach the vessel), it is very unlikely that an entire 
group of any species of marine mammals in these functional hearing 
groups would be exposed to the airgun array at levels that would 
constitute Level A harassment. For instance, in the case of short-
finned pilot whales, one take by Level A harassment is estimated during 
the North Island 2-D survey (Table 10). Though we are not aware of 
information on the typical group size for short-finned pilot whales off 
New Zealand, Ross (2006) reported that short-finned pilot whales off 
Australia tend to occur in groups of 10-30 individuals. The Level A 
harassment zone (SPL) for short-finned pilot whales (considered to be 
in the mid-frequency functional hearing group) for the North Island 2-D 
survey is estimated to be less than 14 m (Table 6). We believe the 
possibility of a group of 10-30 short-finned pilot whales approaching 
within 14 m of the airgun array and being taken by Level A harassment, 
especially considering the mitigation requirement that the array be 
shut down entirely if a pilot whale approaches within 100 m of the 
array, is so low as to be discountable.
    Even in the case of short-beaked common dolphins, dusky dolphins 
and southern right whale dolphins that approach the vessel, for which 
the power down requirement does not apply, we believe the likelihood 
that a group of bow-riding dolphins would occur within 14 m of the 
array to be so low as to be discountable. For instance, though common 
dolphin group size varies depending on season, depth, sea surface 
temperature, Stockin (2008) reported the most frequently observed group 
size in the Hauraki Gulf to be 21-30 animals. We believe the 
possibility of a group of 21-30 dolphins approaching within 14 m of the 
airgun array and being taken by Level A harassment is so low as to be 
discountable. Therefore, for the species categorized as low-frequency 
cetaceans, mid-frequency cetaceans, phocid pinnipeds and otariid 
pinnipeds, we do not authorize Level A take by group size, when at 
least one take is estimated to occur for the species.
    The Level A harassment zones (peak SPL) for high-frequency 
cetaceans are estimated at 229.2 m, 119.0 m, and 229.2 m, for the North 
Island 2-D, North Island 3-D, and South Island 2-D surveys, 
respectively. We analyzed the potential for a group of any of the 
species in the high-frequency functional hearing group (that occur in 
the survey areas) occurring between 229.2 m (largest distance to the 
isopleth corresponding to the Level A harassment threshold) and 100 m 
(the distance to the 100 m exclusion zone (EZ) for the smallest element 
in the array, for all species in the high-frequency functional hearing 
group) of the array. The species in this group for which Level A take 
is authorized in this IHA include the hourglass dolphin, spectacled 
porpoise and pygmy sperm whale. We are not aware of information on the 
group sizes of these species in the waters off New Zealand. However, 
based on the best available information, estimated group sizes are 
lower than the number of takes authorized, when at least 1 Level A take 
is authorized, for these species: Hourglass dolphin group size was 
reported as averaging 2-6 individuals in Antarctic waters (Santora, 
2012) whereas 15, 10, and 12 takes by Level A harassment are authorized 
(for North Island 2-D, North Island 3-D, and South Island 2-D survey, 
respectively); spectacled porpoise group size was reported as 2 
individuals in Antarctic waters (Sekiguchi et al., 2006), whereas 6 
takes by Level A harassment are authorized for the South Island 2-D 
survey (with 0 Level A takes predicted for the North Island 2-D and 
North Island 3-D surveys); Kogia spp. mean group size was reported as 
1.9 individuals in the California current ecosystem (Barlow, 2010) 
whereas 6, 4, and 5 takes by Level A harassment are authorized (for 
North Island 2-D, North Island 3-D, and South Island 2-D survey, 
respectively). Because the number of

[[Page 56124]]

authorized Level A takes are higher than the respective group sizes for 
these species, we do not authorize Level A take by group size, when at 
least one take is estimated to occur for the species, for any marine 
mammal species.
    Comment 6: The Commission recommended that NMFS include a take 
table showing the total numbers of takes for the entire activity area 
(territorial seas, exclusive economic zones, and high seas).
    NMFS Response: NMFS does not authorize takes in the territorial 
sea. However, we have included a table showing the take estimates in 
the New Zealand territorial sea (see Table 14).
    Comment 7: The Commission recommended that NMFS include pygmy and 
gingko-toothed beaked whales and dwarf sperm whales in the IHA, based 
on range estimates and stranding records in New Zealand for these 
species.
    NMFS Response: NMFS has reviewed the available literature available 
on the strandings of these three species. While stranding records exist 
for these species in various locations on the coast of New Zealand, 
these strandings appear to have been isolated events in all cases and 
do not suggest that the density of these species in the survey area is 
such that take of these species is likely to occur. Therefore, we do 
not authorize take of ginkgo-toothed beaked whales, pygmy beaked 
whales, and dwarf sperm whales in this IHA.
    Comment 8: The Commission recommended that NMFS prohibit L-DEO from 
using power downs during its survey.
    NMFS Response: NMFS agrees with the Commission that limiting the 
use of power downs can be beneficial in reducing the overall sound 
input in the marine environment from geophysical surveys; as such, NMFS 
is requiring that power downs in this IHA occur for no more than a 
maximum of 30 minutes at any time. NMFS is still in the process of 
determining best practice, via solicitation of public comment, for the 
use of power downs as a mitigation measure in ITAs for geophysical 
surveys. We will take into consideration the Commission's 
recommendation that power downs be eliminated as a mitigation measure 
as we work toward a determination on best practices for the use of 
power downs in IHAs for marine geophysical surveys. Ultimately our 
determination will be based on the best available science and will be 
communicated clearly to ITA applicants.
    Comment 9: The Commission recommended that NMFS condition the IHA 
to require LDEO to abide by the regulatory requirements of New 
Zealand's Exclusive Economic Zone and Continental Shelf Act and, 
through it, the mandatory provisions of the 2013 Code of Conduct for 
Minimizing Acoustic Disturbance to Marine Mammals from Seismic Survey 
Operations (Code).
    NMFS Response: NMFS does not have the statutory authority to 
require L-DEO to abide by the regulatory requirements of New Zealand's 
Exclusive Economic Zone and Continental Shelf Act and, through it, the 
mandatory provisions of the Code. Under the MMPA, L-DEO must comply 
with the requirements of the IHA. However, we also encourage L-DEO to 
comply with the provisions of the Code to the extent possible.
    Comment 10: The Commission recommended that NMFS include a 
mitigation measure requiring shutdown of the airgun array upon 
observation of a large whale with calf or an aggregation of large 
whales at any distance, in an effort to minimize impacts on mysticetes 
and sperm whales that are engaged in biologically-important behaviors 
(e.g., nursing, breeding, feeding).
    NMFS Response: NMFS has included mitigation measures in the final 
IHA requiring shutdown of the airgun array upon observation of a large 
whale with calf and upon observation of an aggregation of large whales 
at any distance, as recommended by the Commission. See the section on 
Mitigation, below, for more details.
    Comment 11: The Commission recommended that NMFS incorporate 
mitigation measures that would require both visual observations and 
passive acoustic methods to implement shutdown procedures when any 
sperm whale, beaked whale, or Kogia spp. are detected, which would 
bolster mitigation efforts as a whole, affording NMFS the ability to 
further reduce the impacts on those deep-diving species. The Commission 
also recommended a consistent approach for requiring all geophysical 
and seismic survey operators to abide by the same general mitigation 
measures.
    NMFS Response: NMFS has included a mitigation measure in the final 
IHA requiring shutdown of the airgun array upon acoustic detection of a 
beaked whale, sperm whale, or Kogia spp., as recommended by the 
Commission, with an exception for sperm whales in instances where the 
acoustic detection can be definitively localized and the sperm whale is 
confirmed to be located outside the 500 m exclusion zone. See the 
Response to Comment 13 and the section on Mitigation, below, for 
further details, including the reasoning behind the shutdown 
requirement upon acoustic detection and the sperm whale exception.
    NMFS considered requirement of shutdown upon visual detection of 
sperm whales at any distance. We have included a mitigation measure 
that would require shutdown of the array on acoustic detection of sperm 
whales at any distance (except in instances where the sperm whale can 
be definitively localized as being located outside the 500 m EZ). The 
reasoning behind the shutdown requirement upon acoustic detection is 
provided in more detail below (see section on Mitigation). Based on the 
best available information, we believe that acoustic detections of 
sperm whales would most likely be representative of the foraging 
behavior we intend to minimize disruption of, while visual observations 
of sperm whales would represent resting between bouts of such behavior. 
Occurrence of resting sperm whales at distances beyond the 500 m 
exclusion zone may not indicate a need to implement shutdown. 
Therefore, this measure has not been added to the final IHA. This is 
discussed in greater detail in the Mitigation section, below.
    NMFS agrees with the Commission that consistency in mitigation 
measures across incidental take authorizations (ITAs) for similar 
activities is a worthwhile goal, to the extent practicable. However, 
NMFS also must determine the most appropriate mitigation measures for a 
given ITA, taking into account factors unique to that ITA, such as the 
type, extent, location, and timing of activities, and therefore, 
complete consistency in mitigation measures across ITAs for similar 
activities will not always be possible. NMFS is still in the process of 
determining best practice, via solicitation of public comment, for the 
use of a suite of mitigation measures in ITAs for marine geophysical 
surveys. We will take into consideration the Commission's 
recommendations with regard to mitigation measures as we work toward 
determinations on best practices for mitigation measures in IHAs for 
geophysical surveys. Ultimately our determination will be based on the 
best available science and will be communicated clearly to ITA 
applicants.
    Comment 12: The Commission expressed concern that reporting of the 
manner of taking and the numbers of animals incidentally taken should 
account for all animals in the various survey areas, including those 
animals directly on the trackline that are not detected, and how well 
animals are

[[Page 56125]]

detected based on the distance from the observer (accounted for by g(0) 
and f(0) values). The Commission has recommended a method for 
estimating the number of cetaceans in the vicinity of geophysical 
surveys based on the number of groups detected and recommended that 
NMFS require L-DEO to use this method for estimating g(0) and f(0) 
values to better estimate the numbers of marine mammals taken by Level 
A and Level B harassment.
    NMFS Response: NMFS agrees that reporting of the manner of taking 
and the numbers of animals incidentally taken should account for all 
animals taken, including those animals directly on the trackline that 
are not detected and how well animals are detected based on the 
distance from the observer, to the extent practicable. NMFS appreciates 
the Commission's recommendations but we believe that the Commission's 
described method needs further consideration in relation to the 
observations conducted during marine geophysical surveys. Therefore, at 
this time we do not prescribe a particular method for accomplishing 
this task. We look forward to engaging further both L-DEO, the 
Commission and other applicants to reach a determination on the most 
suitable method to for estimating g(0) and f(0) values.
    Comment 13: A member of the general public expressed concern 
regarding the effective dates of the IHA and that there had not been 
adequate consultation within New Zealand, including that the local 
indigenous populations were not consulted.
    NMFS Response: NMFS has followed and met its statutory obligations 
with respect to notifying the public of, and requesting comments on, 
the proposed IHA, and has considered and responded to all public 
comments received. With respect to concerns regarding communication 
within New Zealand, including with indigenous groups, NMFS does not 
have the authority to require communication between L-DEO and the New 
Zealand government or interested parties within New Zealand. In 
addition, the MMPA provides authority only to authorize the take of 
marine mammals that may occur incidental to the activity; NMFS does not 
permit the activity itself. However, the National Science Foundation, 
as the funder of the survey, has been in communication with the New 
Zealand Department of Conservation (NZDOC) regarding the survey, and 
recommendations from the NZDOC have been incorporated in the IHA. For 
instance, the power down waiver for bottlenose dolphins has been 
removed from the IHA based on input received from the NZDOC (see the 
section on Revisions to the IHA That Have Occurred Since the Proposed 
IHA, below, for details). The comment also stated that lack of 
communication with indigenous groups represents a breach of the Treaty 
of Waitangi; however, the United States is not a Party to the Treaty of 
Waitangi.
    Comment 14: A member of the general public expressed concern 
regarding potential impacts to marine mammals, including impacts to 
mother-calf pairs, South Island Hector's dolphins, southern right 
whales, blue whales, killer whales, sperm whales and beaked whales. The 
commenter also expressed concern that tourism companies could be hurt 
financially by the planned surveys
    NMFS Response: The commenter expressed concern that the timing of 
the planned surveys overlaps with calving season for delphinids and 
that noise from the planned surveys could interfere with mother-calf 
communication. The commenter did not provide any detailed or 
substantive information or references to support this statement or 
change our analyses. We recognize that restricted communication as a 
result of increased noise from seismic surveys may be of concern, which 
is why we have incorporated mitigation measures to minimize the 
potential for this to occur. For instance, the IHA requires that the 
airgun array be shut down upon observation of a large whale with calf 
at any distance; additionally, the airgun array would be powered down 
to a single 40 in\3\ airgun if any delphinids (other than those that 
approach the vessel (i.e., bow ride)) are detected within 500 m of the 
array. We have determined these measures ensure the least practicable 
impact on the species potentially affected. The commenter expressed 
concern regarding potential impacts to blue whales, killer whales, 
sperm whales and other deep-diving whales. However, the comments 
specific to blue whales, killer whales, sperm whales and other deep-
diving whales did not include any supporting information nor did they 
recommend any specific action. NMFS believes the mitigation and 
monitoring measures incorporated in the IHA, including measures 
specific to sperm whales and other deep diving cetaceans, ensure the 
least practicable impact on the species potentially affected (see the 
Mitigation section, below).
    The commenter also expressed concern regarding South Island 
Hector's dolphins, specifically the subpopulation that resides in Te 
Waewae Bay, noting that they exhibit high site fidelity and that the 
survey will coincide with Hector's dolphin calving season. We agree 
with the concerns raised by this comment, especially given the 
proximity of the planned track lines of the South Island 2-D survey to 
Te Waewae Bay (see Figure 2 in the IHA application). In response to 
this concern, we have incorporated a mitigation measure that would 
require shutdown of the array upon visual detection of South Island 
Hector's dolphins at any distance. Based on this comment, we have also 
added a mitigation measure requiring shutdown of the array upon 
acoustic detection of a Hector's dolphin during North and South Island 
surveys, if the acoustic detection can be definitively identified as a 
Hector's dolphin. More information is provided below in the section on 
Revisions to the IHA That Have Occurred Since the Proposed IHA.
    Regarding the concern that tourism companies could be impacted 
financially by the planned surveys, this statement was not supported by 
any information and we cannot speculate as to any potential effects to 
tourism companies as a result of L-DEO's survey. NMFS also does not 
have any authority under the MMPA to restrict activities based on 
potential impacts to tourism, as we do not authorize the activity 
itself, as described above.
    Comment 15: A member of the general public expressed concern that 
the abundances for marine mammals provided in Table 2 in the Notice of 
the Proposed IHA (82 FR 45116; September 27, 2017) do not reflect 
abundance estimates for those marine mammals specifically around New 
Zealand because they incorporate population estimates from the entire 
Southern Hemisphere. The comment asserted that many of the marine 
mammal species have unique and important subpopulations. The commenter 
specifically recommended that the abundance estimates for southern 
right whale and killer whale be revised.
    NMFS Response: The commenter did not suggest specific revisions to 
abundance estimates, with the exception of southern right whale and 
killer whale. With respect to southern right whale and killer whale the 
commenter did not provide specific information to support revisions to 
our abundance estimates for those species. For southern right whales, 
the commenter referenced an estimated abundance of 200. The source for 
this estimate was the Web site of a New Zealand based non-governmental 
organization; however, this Web site does not cite any literature to 
support this estimate, therefore we have no way

[[Page 56126]]

to verify the accuracy of this figure or revise our abundance estimate 
based on it. For killer whale abundance, the commenter referenced an 
estimated abundance of 150-200 individuals. The source for this 
estimate is a NZDOC Web site; however, this Web site does not cite any 
literature to support this estimate, therefore we have no way to verify 
the accuracy of this figure or revise our abundance estimate based on 
it. The commenter did not provide any specific recommendations 
regarding revisions to abundance estimates for any other species. The 
commenter refers to marine mammals abundances described in Baker et al. 
(2016); however, that document does not provide abundance estimates for 
specific marine mammal species.
    With regard to the abundance estimates for the other species in 
Table 2, we made our findings about the applicable management units and 
abundance estimates for those species based on the best available 
information.
    Comment 16: A member of the general public expressed concerns with 
and offered suggestions about some of the mitigation measures. Specific 
concerns or suggestions raised by the commenter were related to: 
Mitigation measures for surveys during nighttime and low visibility; 
the number and location of PSOs relative to the survey vessel; 
verification of sound propagation modeling; size of exclusion zones; 
use of power downs; mitigation for the multibeam echosounder (MBES) and 
sub-bottom profiler (SBP); and shutdown requirements for Hector's 
dolphins.
    NMFS Response: The commenter expressed concern that mitigation 
measures for surveys during nighttime and low visibility conditions 
were limited to use of PAM. However, the IHA also requires that L-DEO 
must provide a night-vision device suited for the marine environment 
for use during nighttime ramp-up pre-clearance, which must include 
automatic brightness and gain control, bright light protection, 
infrared illumination, and optics suited for low-light situations. We 
have determined that the mitigation measures specific to nighttime and 
low visibility conditions ensure the least practicable impact on 
species potentially affected.
    The commenter expressed concern that the number of required PSOs is 
not sufficient, and suggested observers be deployed on other vessels in 
addition to the Langseth. However, we believe that mitigation and 
monitoring measures required in the IHA can be adequately performed by 
the number of PSOs required in the IHA, and that this has been 
demonstrated through numerous monitoring reports submitted for past 
IHAs for similar activities (i.e., marine geophysical surveys conducted 
on the Langseth) which have used the same number of PSOs and the same 
PSO staffing configurations as that required in this IHA. We believe 
the number and location of PSOs required in the IHA ensure the least 
practicable impact on species potentially affected.
    The commenter expressed concern that sound propagation should be 
verified in the field to ensure accuracy of the sound propagation 
models. The commenter expressed that this would be of particular 
concern in regards to the South Island Hector's dolphin subpopulation 
that has site fidelity to Te Waewae Bay. As described above, NMFS 
believes that L-DEO's current modeling approach represents the best 
available information for NMFS to reach determinations for this IHA. We 
refer the reader to the response to Comment 1, above, for a more 
detailed discussion of L-DEO's acoustic modeling methodology. In 
addition, as described above, results of acoustic modeling represent 
just one component of the analysis during the MMPA authorization 
process, as NMFS also takes into consideration other factors associated 
with the activity and, as described herein, our determination of the 
appropriate distance for mitigation zones is not based on acoustic 
modeling. With respect to the use of sound source verification to 
verify the distances to isopleths that coincide with harassment 
thresholds for Hector's dolphins, we have incorporated a requirement in 
the IHA that the array must be shut down upon visual or acoustic 
detection of Hector's dolphins at any distance, as described below.
    The commenter expressed concern about the 500 m exclusion zone and 
recommended that the exclusion zone should be extended to between 1-1.5 
km for all species of marine mammals detected visually and/or 
acoustically, and referred to more conservative zones required by the 
Code for some marine mammals. As described in the Federal Register 
Notice of the Proposed IHA (82 FR 45116; September 27, 2017), our use 
of 500 m as the EZ is based on a reasonable combination of factors. 
This zone is expected to contain all potential auditory injury for all 
marine mammals (high-frequency, mid-frequency and low-frequency 
cetacean functional hearing groups and otariid and phocid pinnipeds) as 
assessed against peak pressure thresholds (NMFS, 2016) (Tables 7, 8, 
9). It is also expected to contain all potential auditory injury for 
high-frequency and mid-frequency cetaceans as well as otariid and 
phocid pinnipeds as assessed against SELcum thresholds 
(NMFS, 2016) (Tables 7, 8, 9). Additionally, the 500 m EZ is expected 
to minimize the likelihood that marine mammals will be exposed to 
levels likely to result in more severe behavioral responses. It has 
also proven to be practicable through past implementation in seismic 
surveys conducted for the oil and gas industry. A practicable criterion 
such as the proposed 500 m EZ has the advantage of simplicity while 
still providing in most cases a zone larger than relevant auditory 
injury zones, given realistic movement of source and receiver. With 
respect to the Code, as described above, NMFS does not have the 
statutory authority to require L-DEO to abide by the requirements of 
the Code outside a finding that the Code represents mitigation 
necessary to effect the least practicable impact on the affected marine 
mammal species or stocks, which is not the case here. However, we 
encourage L-DEO to comply with the provisions of the Code to the extent 
possible.
    The commenter expressed concern that the use of the single 40 in\3\ 
airgun during power downs adds more sound to the marine environment, 
though this comment appears to be based on the mistaken impression that 
the single airgun may be used ``continuously.'' We note that the use of 
the single 40 in\3\ airgun during power downs is, in fact, permitted 
for no more than 30 minutes at any time (as described in greater detail 
in the Mitigation section below). The comment did not cite any 
substantive information regarding power downs or make any 
recommendations regarding power downs, therefore we do not further 
revise the requirements specific to power downs in response to this 
comment.
    The commenter expressed concern with the use of the MBES and SBP, 
citing a report on a mass stranding of melon-headed whales on the 
Madagascar coast in 2008 that was attributed to use of a MBES (Southall 
et al., 2013). The commenter also requested that NMFS require that the 
MBES be shut down in instances when mitigation measures require 
shutdown of the airgun array.
    A Kongsberg EM 122 MBES would be operated continuously during the 
proposed surveys, but not during transit to and from the survey areas. 
Due to the lower source level of the MBES relative to the Langseth's 
airgun array, sounds from the MBES are expected to be effectively 
subsumed by the sounds from the airgun array when both sources are 
operational. Thus, NMFS has

[[Page 56127]]

determined that any marine mammal potentially exposed to sounds from 
the MBES would already have been exposed to sounds from the airgun 
array, which are expected to propagate further in the water, when both 
sources are operational. During periods when the airguns are inactive 
and the MBES is operational, NMFS has determined that, given the 
movement and speed of the vessel and the intermittent and narrow 
downward-directed nature of the sounds emitted by the MBES (each ping 
emitted by the MBES consists of eight (in water >1,000 m deep) or four 
(<1,000 m) successive fan-shaped transmissions, each ensonifying a 
sector that extends 1[deg] fore-aft), the MBES would result in no more 
than one or two brief ping exposures to any individual marine mammal, 
if any exposure were to occur.
    Regarding the 2008 mass stranding of melon-headed whales in 
Madagascar, it should be noted that the report to which the commenter 
refers states that while the MBES was determined as the most likely 
cause of the stranding event, there was no unequivocal and easily 
identifiable single cause of the event, such as those that have been 
implicated in previous marine mammal mortalities (e.g., entanglement, 
vessel strike, identified disease) or mass stranding events (e.g., 
weather, extreme tidal events, predator presence, anthropogenic noise) 
(Southall et al., 2013). The report also notes that the 2008 mass 
stranding event in Madagascar was the first known such marine mammal 
mass stranding event closely associated with relatively high-frequency 
mapping sonar systems such as MBES and that similar MBES systems are in 
fact commonly used in hydrographic surveys around the world over large 
areas without such events being previously documented (Southall et al., 
2013). The report found that in the case of the 2008 mass stranding 
event, environmental, social, or some other confluence of factors 
(e.g., shoreward-directed surface currents and elevated chlorophyll 
levels in the area preceding the stranding) may have meant that that 
particular group of whales was oriented relative to the directional 
movement of the survey vessel (the vessel moved in a directed manner 
down the shelf-break; Southall et al., 2013, Figure 2) in such a way 
that an avoidance response caused animals to move into an unfamiliar 
and unsafe out-of-habitat area (Southall et al., 2013). NMFS is not 
aware of any marine mammal stranding events that have been documented 
as a result of exposure to sounds from MBES since the Madagascar mass 
stranding event in 2008. Based on the best available information, we do 
not believe the use of the MBES aboard the Langseth will result in 
marine mammal strandings.
    The commenter expressed concern that a shutdown requirement upon 
any observation of Hector[acute]s dolphins at any distance, including 
upon acoustic detection, is warranted. As described above, based on the 
best available information, NMFS agrees this measure is warranted, and 
has incorporated these requirements in the IHA. See the section on 
Mitigation and the section on Revisions to the IHA That Have Occurred 
Since the Proposed IHA, below, for details.
    In summary, we have determined the mitigation measures contained in 
the IHA ensure the least practicable impact on marine mammal species 
potentially affected.
    Comment 17: A member of the general public expressed that L-DEO 
should employ alternative research technologies, including Vibroseis 
and AquaVib, rather than airguns to perform the planned marine 
geophysical surveys.
    NMFS Response: At this point in time, the alternative technologies 
identified by the commenter are not commercially viable or appropriate 
to meet the needs of the planned surveys. With respect to Vibroseis, 
there is no commercially available marine vibrator system that can be 
used for the planned surveys. The AquaVib is a modified version of a 
land seismic vibrator system that is capable of being placed in very 
shallow water (i.e., a few meters) and in transition zone environments 
(i.e., marshes, etc.); however the AquaVib would not be suitable for L-
DEO's planned surveys. As suggested by the commenter, NMFS has 
requested the National Science Foundation to continue to review and 
consider alternative technologies to support future marine geophysical 
research.
    Comment 18: A member of the general public stated that L-DEO should 
agree to pay for any necropsies of marine mammals that strand around 
the entire coastline of New Zealand during and after the survey.
    NMFS Response: NMFS does not anticipate that the survey will result 
in strandings of marine mammals. We also do not have the authority to 
require applicants to fund marine mammal necropsies. However, should 
any stranded animals be observed during the surveys, we have included 
reporting measures to ensure L-DEO promptly notifies NMFS and the NZDOC 
(see the section on Reporting, below).
    In addition to the comments above, NMFS received comments from the 
MSROC and an additional comment from the general public. The comment 
letter from the MSROC affirmed that there is significant support from 
the MSROC for the IHA to be issued for the proposed surveys and for the 
surveys to be conducted. A private citizen expressed concern that 
animals should not be harmed in the process of surveying or studying 
them. NMFS considered this comment, however, it did not contain any 
substantive information regarding the potential for the proposed 
surveys to harm marine mammals.

Revisions to the IHA That Have Occurred Since the Proposed IHA

    Based on public comments and a recalculation of the take estimates 
in the proposed IHA, we have made revisions to the IHA since we 
published the notice of the proposed IHA in the Federal Register (82 FR 
45116; September 27, 2017). Those revisions are described below.
    Revisions to the take estimates--Take estimates in the final IHA 
have been revised slightly since we published the notice of the 
proposed IHA in the Federal Register (82 FR 45116; September 27, 2017), 
due to a math error in calculating the 25 percent correction factor for 
uncertainty in density estimates applied to the overall take estimate. 
This has resulted in higher take estimates in some cases, and lower 
take estimates in some cases, in comparison to the take estimates 
described in the notice of the proposed IHA. Revised take estimates are 
shown in Tables 10, 11, 12 and 13. These revisions have not impacted 
our preliminary determinations.
    Shutdown requirement upon visual detection of an aggregation of 
large whales at any distance--We have added a mitigation measure that 
requires that the airgun array be shut down upon visual detection of an 
aggregation (i.e., six or more animals) of large whales of any species 
(i.e., sperm whale or any baleen whale) at any distance. This measure 
is discussed in greater detail in the Mitigation section, below.
    Shutdown requirement upon visual detection of South Island Hector's 
dolphins--We have added a mitigation measure that requires that the 
airgun array be shut down upon visual detection of a Hector's dolphin 
during the South Island survey. Hector's dolphins have relatively small 
home ranges and high site fidelity; a survey in 2002 found that the 
majority of Hector's dolphins ranged less than 60 km (Brager et al., 
2002); along-shore home range is typically less than 50 km (Oremus et 
al., 2012). There are at least three,

[[Page 56128]]

genetically distinct, regional populations of South Island Hector's 
dolphin (Dawson et al. 2004); a genetically distinct and localized 
population occurs in Te Waewae Bay (Mackenzie and Clement, 2014)). Due 
to the limited range and high site fidelity of the population of 
Hector's dolphin that occurs in Te Waewae Bay and the proximity of the 
planned South Island 2-D survey with Te Waewae Bay (see Figure 2 in the 
IHA application), NMFS has determined that shutdown of the array upon 
visual detection of Hector's dolphins during the South Island 2-D 
survey is warranted.
    Shutdown requirement upon acoustic detection of Hector's dolphins, 
beaked whales, sperm whales, or Kogia spp.--We have added a mitigation 
measure that requires that the airgun array be shut down upon acoustic 
detection of Hector's dolphins, beaked whales, sperm whales, or Kogia 
spp. (with an exception for sperm whales only, if the acoustic 
detection can be localized and it is determined the sperm whale is 
outside the 500 m EZ). The requirement to shut down the airgun array 
upon visual detection of a beaked whale or Kogia spp. at any distance 
was included in the Federal Register notice of the proposed IHA (82 FR 
45116; September 27, 2017) in recognition of the fact that these 
species are behaviorally sensitive deep divers and it is possible that 
disturbance could provoke a severe behavioral response leading to 
injury (e.g., Wursig et al., 1998; Cox et al., 2006). The requirement 
to shut down the airgun array upon visual detection of a Hector's 
dolphin at any distance was included in the Federal Register notice of 
the proposed IHA (82 FR 45116; September 27, 2017), specifically for 
the planned North Island surveys; we have since added the requirement 
that the array must be shut down upon observation of a Hector's 
dolphin, at any distance, during the South Island survey (as described 
above). The intent behind the requirement to shut down upon acoustic 
detection is the same as that behind the requirement to shut down upon 
visual detection. As discussed above, shutdown upon visual detection of 
sperm whales at any distance is not required in the IHA (the reasoning 
for this decision is described in further detail in the Mitigation 
section, below). However, we have determined that meaningful measures 
are warranted to minimize potential disruption of foraging behavior in 
sperm whales. This measure (i.e., shutdown upon acoustic detection of 
beaked whales, sperm whales, or Kogia spp., with an exception for sperm 
whales only, if the acoustic detection can be localized and it is 
determined the sperm whale is outside the 500 m EZ) is discussed in 
greater detail in the Mitigation section, below.
    Revision to power down waiver for certain delphinids--In the 
Federal Register notice of the proposed IHA (82 FR 45116; September 27, 
2017), NMFS proposed a waiver to the requirement to power down the 
array upon marine mammals observed within or approaching the 500 m 
exclusion zone that would apply specifically to cetaceans of the genera 
Tursiops, Delphinus and Lissodelphis that approach the vessel (e.g., 
bow riding). We have revised this waiver to the requirement to power 
down the array such that it applies to all small dolphins except 
spectacled porpoise and bottlenose, hourglass, and Hector's dolphins. 
We have revised the species for which the power down waiver applies 
because we had previously mistakenly excluded all dolphins in the 
genera Lagenorhynchus from the power down waiver, based on a concern 
(which we still hold) that cetaceans considered to be in the high 
frequency functional hearing group would be more sensitive to airgun 
sounds; however, as dusky dolphins (Lagenorhynchus obscurus) are in 
fact considered to be in the mid frequency functional hearing group, we 
believe the power down waiver should apply to dusky dolphins. 
Additionally, we have removed cetaceans of the genera Tursiops (i.e., 
bottlenose dolphins) from the power down waiver in response to concerns 
expressed by the NZDOC, as bottlenose dolphins are listed as a species 
of concern in New Zealand and are particularly susceptible to impacts 
from human activities due to their coastal nature. Therefore the power 
down waiver will not apply for bottlenose dolphins. Effectively, the 
species which are included in the power down waiver are: short-beaked 
common dolphin (Delphinus delphis), dusky dolphin (Lagenorhynchus 
obscurus) and southern right whale dolphin (Lissodelphis peronii). 
Finally, we specified in the proposed IHA that the waiver would only 
apply if the animals were traveling, including approaching the vessel. 
However, we have removed that requirement from the IHA, based on an 
acknowledgement that it would have required subjective on-the-spot 
decision-making on the part of PSOs, which may have resulted in 
differential implementation as informed by individual PSOs' experience, 
background, and/or training.

Description of Marine Mammals in the Area of Specified Activities

    Section 4 of the application summarizes available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS' Stock Assessment Reports (SAR; www.nmfs.noaa.gov/pr/sars/), and more general information about these species (e.g., 
physical and behavioral descriptions) may be found on NMFS' Web site 
(www.nmfs.noaa.gov/pr/species/mammals/).
    Table 2 lists all species with expected potential for occurrence in 
the southwest Pacific Ocean off New Zealand and summarizes information 
related to the population, including regulatory status under the MMPA 
and ESA. The populations of marine mammals considered in this document 
do not occur within the U.S. EEZ and are therefore not assigned to 
stocks and are not assessed in NMFS' Stock Assessment Reports 
(www.nmfs.noaa.gov/pr/sars/). As such, information on potential 
biological removal (PBR; defined by the MMPA as the maximum number of 
animals, not including natural mortalities, that may be removed from a 
marine mammal stock while allowing that stock to reach or maintain its 
optimum sustainable population) and on annual levels of serious injury 
and mortality from anthropogenic sources are not available for these 
marine mammal populations.
    In addition to the marine mammal species known to occur in planned 
survey areas, there are 16 species of marine mammals with ranges that 
are known to potentially occur in the waters of the planned survey 
areas, but they are categorized as ``vagrant'' under the New Zealand 
Threat Classification System (Baker et al., 2016). These species are: 
The ginkgo-toothed whale (Mesoplodon ginkgodens); pygmy beaked whale 
(M. peruvianus); dwarf sperm whale (Kogia sima); pygmy killer whale 
(Feresa attenuata); melon-headed whale (Peponocephala electra); Risso's 
dolphin (Grampus griseus); Fraser's dolphin (Lagenodelphis hosei), 
pantropical spotted dolphin (Stenella attenuata); striped dolphin (S. 
coeruleoalba); rough-toothed dolphin (Steno bredanensis); Antarctic fur 
seal (Arctocephalus gazelle); Subantarctic fur seal (A. tropicalis); 
leopard seal (Hydrurga leptonyx); Weddell seal (Leptonychotes 
weddellii); crabeater seal (Lobodon carcinophagus); and Ross seal 
(Ommatophoca rossi). Except for Risso's

[[Page 56129]]

dolphin and leopard seal, for which there have been several sightings 
and strandings reported in New Zealand (Clement 2010; Torres 2012; 
Berkenbusch et al. 2013; NZDOC 2017), the other ``vagrant'' species 
listed above are not expected to occur in the planned survey areas and 
are therefore not considered further in this document.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals estimated within a particular 
study or survey area. All values presented in Table 2 are the most 
recent available at the time of publication.

                      Table 2--Marine Mammals That Could Occur in the Planned Survey Areas
----------------------------------------------------------------------------------------------------------------
                                                                           ESA/MMPA status;        Population
            Common name                Scientific name        Stock      strategic  (Y/N) \1\     abundance \2\
----------------------------------------------------------------------------------------------------------------
                      Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
----------------------------------------------------------------------------------------------------------------
                                                Family Balaenidae
----------------------------------------------------------------------------------------------------------------
Southern right whale..............  Eubalaena australis..          N/A  E/D;Y                         \3\ 12,000
----------------------------------------------------------------------------------------------------------------
                                        Family Balaenopteridae (rorquals)
----------------------------------------------------------------------------------------------------------------
Humpback whale....................  Megaptera                      N/A  -/-; N                        \3\ 42,000
                                     novaeangliae.
Bryde's whale.....................  Balaenoptera edeni...          N/A  -/-; N                        \4\ 48,109
Common minke whale................  Balaenoptera                   N/A  -/-; N                   \5\ \6\ 750,000
                                     acutorostrata.
Antarctic minke whale.............  Balaenoptera                   N/A  -/-; N                   \5\ \6\ 750,000
                                     bonaerensis.
Sei whale.........................  Balaenoptera borealis          N/A  E/D;Y                         \5\ 10,000
Fin whale.........................  Balaenoptera physalus          N/A  E/D;Y                         \5\ 15,000
Blue whale........................  Balaenoptera musculus          N/A  E/D;Y                      \3\ \5\ 3,800
----------------------------------------------------------------------------------------------------------------
                                              Family Cetotheriidae
----------------------------------------------------------------------------------------------------------------
Pygmy right whale.................  Caperea marginata....          N/A  -/-; N                               N/A
----------------------------------------------------------------------------------------------------------------
                        Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
----------------------------------------------------------------------------------------------------------------
                                               Family Physeteridae
----------------------------------------------------------------------------------------------------------------
Sperm whale.......................  Physeter                       N/A  E/D;Y                         \5\ 30,000
                                     macrocephalus.
----------------------------------------------------------------------------------------------------------------
                                                 Family Kogiidae
----------------------------------------------------------------------------------------------------------------
Pygmy sperm whale.................  Kogia breviceps......          N/A  -/-; N                               N/A
----------------------------------------------------------------------------------------------------------------
                                        Family Ziphiidae (beaked whales)
----------------------------------------------------------------------------------------------------------------
Cuvier's beaked whale.............  Ziphius cavirostris..          N/A  -/-; N                   \5\ \7\ 600,000
Arnoux's beaked whale.............  Berardius arnuxii....          N/A  -/-; N                   \5\ \7\ 600,000
Shepherd's beaked whale...........  Tasmacetus shepherdi.          N/A  -/-; N                   \5\ \7\ 600,000
Hector's beaked whale.............  Mesoplodon hectori...          N/A  -/-; N                   \5\ \7\ 600,000
True's beaked whale...............  Mesoplodon mirus.....          N/A  -/-; N                               N/A
Southern bottlenose whale.........  Hyperoodon planifrons          N/A  -/-; N                   \5\ \7\ 600,000
Gray's beaked whale...............  Mesoplodon grayi.....          N/A  -/-; N                   \5\ \7\ 600,000
Andrew's beaked whale.............  Mesoplodon bowdoini..          N/A  -/-; N                   \5\ \7\ 600,000
Strap-toothed beaked whale........  Mesoplodon layardii..          N/A  -/-; N                   \5\ \7\ 600,000
Blainville's beaked whale.........  Mesoplodon                     N/A  -/-; N                   \5\ \7\ 600,000
                                     densirostris.
Spade-toothed beaked whale........  Mesoplodon traversii.          N/A  -/-; N                   \5\ \7\ 600,000
----------------------------------------------------------------------------------------------------------------
                                               Family Delphinidae
----------------------------------------------------------------------------------------------------------------
Bottlenose dolphin................  Tursiops truncatus...          N/A  -/-; N                               N/A
Short-beaked common dolphin.......  Delphinus delphis....          N/A  -/-; N                               N/A
Dusky dolphin.....................  Lagenorhynchus                 N/A  -/-; N                       \8\ 12,000-
                                     obscurus.                                                            20,000
Hourglass dolphin.................  Lagenorhynchus                 N/A  -/-; N                       \5\ 150,000
                                     cruciger.
Southern right whale dolphin......  Lissodelphis peronii.          N/A  -/-; N                               N/A
Risso's dolphin...................  Grampus griseus......          N/A  -/-; N                               N/A
South Island Hector's dolphin.....  Cephalorhynchus                N/A  T/D;Y                         \9\ 14,849
                                     hectori hectori.
Maui dolphin......................  Cephalorhynchus                N/A  E/D;Y                            \10\ 63
                                     hectori maui.
False killer whale................  Pseudorca crassidens.          N/A  -/-; N                               N/A
Killer whale......................  Orcinus orca.........          N/A  -/-; N                        \5\ 80,000
Long-finned pilot whale...........  Globicephala melas...          N/A  -/-; N                       \5\ 200,000
Short-finned pilot whale..........  Globicephala                   N/A  -/-; N                               N/A
                                     macrorhynchus.
----------------------------------------------------------------------------------------------------------------
                                         Family Phocoenidae (porpoises)
----------------------------------------------------------------------------------------------------------------
Spectacled porpoise...............  Phocoena dioptrica...          N/A  -/-; N                               N/A
----------------------------------------------------------------------------------------------------------------

[[Page 56130]]

 
                                     Order Carnivora--Superfamily Pinnipedia
----------------------------------------------------------------------------------------------------------------
                                  Family Otariidae (eared seals and sea lions)
----------------------------------------------------------------------------------------------------------------
New Zealand fur seal..............  Arctocephalus                  N/A  -/-; N                       \8\ 200,000
                                     forsteri.
New Zealand sea lion..............  Phocarctos hookeri...          N/A  -/-; N                        \11\ 9,880
----------------------------------------------------------------------------------------------------------------
                                         Family Phocidae (earless seals)
----------------------------------------------------------------------------------------------------------------
Leopard seal......................  Hydrurga leptonyx....          N/A  -/-; N                       \8\ 222,000
Southern elephant seal............  Mirounga leonina.....          N/A  -/-; N                       \8\ 607,000
----------------------------------------------------------------------------------------------------------------
N/A = Not available or not assessed.
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-)
  indicates that the species is not listed under the ESA or designated as depleted under the MMPA. Under the
  MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or which is
  determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or
  stock listed under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ Abundance for the Southern Hemisphere or Antarctic unless otherwise noted.
\3\ IWC (2016).
\4\ IWC (1981).
\5\ Boyd (2002).
\6\ Dwarf and Antarctic minke whales combined.
\7\ All Antarctic beaked whales combined.
\8\ Estimate for New Zealand; NZDOC 2017.
\9\ Estimate for New Zealand; MacKenzie and Clement 2016.
\10\ Estimate for New Zealand; Baker et al. (2016).
\11\ Geschke and Chilvers (2009).

    All species that could potentially occur in the planned survey 
areas are included in table 2. However, of the species described in 
Table 2, the temporal and/or spatial occurrence of one subspecies, the 
Maui dolphin (also known as the North Island Hector's dolphin), is such 
that take is not expected to occur as a result of the surveys. The Maui 
dolphin is one of two subspecies of Hector's dolphin (the other being 
the South Island Hector's dolphin), both of which are endemic to New 
Zealand. The Maui dolphin has been demonstrated to be genetically 
distinct from the South Island subspecies of Hector's dolphin based on 
studies of mitochondrial and nuclear DNA (Pichler et al. 1998). It is 
currently considered one of the rarest dolphins in the world with a 
population size estimated at just 55-63 individuals (Hamner et al. 
2014; Baker et al. 2016). Historically, Hector's dolphins are thought 
to have ranged along almost the entire coastlines of both the North and 
South Islands of New Zealand, though their present range is 
substantially smaller (Pichler 2002). The range of the Maui dolphin in 
particular has undergone a marked reduction (Dawson et al. 2001; 
Slooten et al. 2005), with the subspecies now restricted to the 
northwest coast of the North Island, between Maunganui Bluff in the 
north and Whanganui in the south (Currey et al. 2012). Occasional 
sightings and strandings have also been reported from areas further 
south along the west coast as well as possible sightings in other areas 
such as Hawke's Bay on the east coast of North Island (Baker 1978, 
Russell 1999, Ferreira and Roberts 2003, Slooten et al. 2005, DuFresne 
2010, Berkenbusch et al. 2013; Torres et al. 2013; Pati[ntilde]o-
P[eacute]rez 2015; NZDOC 2017) though it is unclear whether those 
individuals may have originated from the South Island Hector's dolphin 
populations. A 2016 NMFS Draft Status Review Report concluded the Maui 
dolphin is facing a high risk of extinction as a result of small 
population size, reduced genetic diversity, low theoretical population 
growth rates, evidence of continued population decline, and the ongoing 
threats of fisheries bycatch, disease, mining and seismic disturbances 
(Manning and Grantz 2016). Due to its extremely low population size and 
the fact that the subspecies is not expected to occur in the planned 
survey areas off the North Island, take of Maui dolphins is not 
expected to occur as a result of L-DEO's activities. Therefore the Maui 
dolphin is not discussed further beyond the explanation provided here.
    We have reviewed L-DEO's species descriptions, including life 
history information, distribution, regional distribution, diving 
behavior, and acoustics and hearing, for accuracy and completeness. We 
refer the reader to Section 4 of L-DEO's IHA application, rather than 
reprinting the information here. A detailed description of the species 
likely to be affected by L-DEO's survey, including brief introductions 
to the species and relevant stocks as well as available information 
regarding population trends and threats, and information regarding 
local occurrence, were provided in the Federal Register notice for the 
proposed IHA (82 FR 45116; September 27, 2017). Since that time, we are 
not aware of any changes in the status of these species and stocks; 
therefore, detailed descriptions are not provided here. Please refer to 
that Federal Register notice for these descriptions. Please also refer 
to NMFS' Web site (www.nmfs.noaa.gov/pr/species/mammals/) for 
generalized species accounts.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from marine geophysical survey 
activities have the potential to result in behavioral harassment and, 
in a limited number of instances, auditory injury (PTS) of marine 
mammals in the vicinity of the action area. The Federal Register notice 
of proposed IHA (82 FR 45116; September 27, 2017) included a discussion 
of the effects of anthropogenic noise on marine mammals and their 
habitat, therefore that information is not repeated here; please refer 
to that Federal Register notice for that information. No instances of 
serious injury or mortality are

[[Page 56131]]

expected as a result of L-DEO's survey activities.

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through the IHA, which will inform both NMFS' consideration 
of whether the number of takes is ``small'' and the negligible impact 
determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of 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).
    Authorized takes are primarily by Level B harassment, as use of the 
seismic airguns have the potential to result in disruption of 
behavioral patterns for individual marine mammals. There is also some 
potential for auditory injury (Level A harassment) to result, primarily 
for mysticetes and high frequency cetaceans (i.e., Kogia spp.), due to 
larger predicted auditory injury zones for those functional hearing 
groups. Auditory injury is unlikely to occur for mid-frequency species 
given very small modeled zones of injury for those species. The 
mitigation and monitoring measures are expected to minimize the 
severity of such taking to the extent practicable.
    As described previously, no serious injury or mortality is 
anticipated or authorized for this activity. Below we describe how the 
take is estimated.
    Described in the most basic way, we estimate take by considering: 
(1) Acoustic thresholds above which NMFS believes the best available 
science indicates marine mammals will be behaviorally harassed or incur 
some degree of permanent hearing impairment; (2) the area or volume of 
water that will be ensonified above these levels in a day; (3) the 
density or occurrence of marine mammals within these ensonified areas; 
and (4) and the number of days of activities. Below, we describe these 
components in more detail and present the exposure estimate and 
associated numbers of take authorized.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al. 2011). Based on the best available science and the 
practical need to use a threshold based on a factor that is both 
predictable and measurable for most activities, NMFS uses a generalized 
acoustic threshold based on received level to estimate the onset of 
behavioral harassment. NMFS predicts that marine mammals are likely to 
be behaviorally harassed in a manner we consider to fall under Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 micropascal ([mu]Pa) (rms) for 
continuous sources (e.g. vibratory pile-driving, drilling) and above 
160 dB re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., seismic 
airguns) or intermittent (e.g., scientific sonar) sources. L-DEO's 
activity includes the use of impulsive seismic sources. Therefore, the 
160 dB re 1 [mu]Pa (rms) criteria is applicable for analysis of Level B 
harassment.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (NMFS, 2016) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). The 
Technical Guidance identifies the received levels, or thresholds, above 
which individual marine mammals are predicted to experience changes in 
their hearing sensitivity for all underwater anthropogenic sound 
sources, reflects the best available science, and better predicts the 
potential for auditory injury than does NMFS' historical criteria.
    These thresholds were developed by compiling and synthesizing the 
best available science and soliciting input multiple times from both 
the public and peer reviewers to inform the final product, and are 
provided in Table 3 below. The references, analysis, and methodology 
used in the development of the thresholds are described in NMFS 2016 
Technical Guidance, which may be accessed at: http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm. As described above, L-DEO's activity 
includes the use of intermittent and impulsive seismic sources.

            Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift in Marine Mammals
----------------------------------------------------------------------------------------------------------------
                                                                    PTS onset thresholds
              Hearing group               ----------------------------------------------------------------------
                                                   Impulsive *                        Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans.............  Lpk,flat: 219 dB;            LE,LF,24h: 199 dB.
                                            LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans.............  Lpk,flat: 230 dB;            LE,MF,24h: 198 dB.
                                            LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans............  Lpk,flat: 202 dB;            LE,HF,24h: 173 dB.
                                            LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).......  Lpk,flat: 218 dB;            LE,PW,24h: 201 dB.
                                            LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)......  Lpk,flat: 232 dB;            LE,OW,24h: 219 dB.
                                            LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
Note: * Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.

[[Page 56132]]

 
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1[mu]Pa2s. In this Table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
  that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
  exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
  is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into estimating the area ensonified above the 
relevant acoustic thresholds.
    The survey entails use of a 36-airgun array with a total discharge 
of 6,600 in\3\ at a tow depth of 9 m and an 18-airgun array with a 
total discharge of 3,300 in\3\ at a tow depth of 7-9 m. Received sound 
levels were predicted by L-DEO's model (Diebold et al., 2010) as a 
function of distance from the 36-airgun array and 18-airgun array and 
for a single 40-in\3\ airgun which would be used during power downs; 
all models used a 9 m tow depth. This modeling approach uses ray 
tracing for the direct wave traveling from the array to the receiver 
and its associated source ghost (reflection at the air-water interface 
in the vicinity of the array), in a constant-velocity half-space 
(infinite homogeneous ocean layer, unbounded by a seafloor). In 
addition, propagation measurements of pulses from the 36-airgun array 
at a tow depth of 6 m have been reported in deep water (approximately 
1600 m), intermediate water depth on the slope (approximately 600-1,100 
m), and shallow water (approximately 50 m) in the Gulf of Mexico in 
2007-2008 (Tolstoy et al. 2009; Diebold et al. 2010).
    For deep and intermediate-water cases, L-DEO determined that the 
field measurements cannot be used readily to derive zone of 
ensonification, as at those sites the calibration hydrophone was 
located at a roughly constant depth of 350-500 m, which may not 
intersect all the SPL isopleths at their widest point from the sea 
surface down to water depths of approximately 2,000 m (See Appendix H 
in NSF-USGS 2011). At short ranges, where the direct arrivals dominate 
and the effects of seafloor interactions are minimal, the data recorded 
at the deep and slope sites are suitable for comparison with modeled 
levels at the depth of the calibration hydrophone. At longer ranges, 
the comparison with the mitigation model--constructed from the maximum 
SPL through the entire water column at varying distances from the 
airgun array--is the most relevant. Please see the IHA application for 
further discussion of summarized results.
    For deep water (>1,000 m), L-DEO used the deep-water radii obtained 
from model results down to a maximum water depth of 2000 m. The radii 
for intermediate water depths (100-1,000 m) were derived from the deep-
water ones by applying a correction factor (multiplication) of 1.5, 
such that observed levels at very near offsets fall below the corrected 
mitigation curve (See Fig. 16 in Appendix H of NSF-USGS, 2011). The 
shallow-water radii were obtained by scaling the empirically derived 
measurements from the Gulf of Mexico calibration survey to account for 
the differences in tow depth between the calibration survey (6 m) and 
the planned surveys (9 m). A simple scaling factor is calculated from 
the ratios of the isopleths determined by the deep-water L-DEO model, 
which are essentially a measure of the energy radiated by the source 
array.
    Measurements have not been reported for the single 40-in\3\ airgun. 
L-DEO model results are used to determine the 160-dB (rms) radius for 
the 40-in\3\ airgun at a 9 m tow depth in deep water (See LGL 2017, 
Figure 6). For intermediate-water depths, a correction factor of 1.5 
was applied to the deep-water model results. For shallow water, a 
scaling of the field measurements obtained for the 36-airgun array was 
used.
    L-DEO's modeling methodology is described in greater detail in the 
IHA application (LGL 2017) and we refer the reader to that document 
rather than repeating it here. The estimated distances to the Level B 
harassment isopleth for the Langseth's 36-airgun array, 18-airgun 
array, and the single 40-in\3\ airgun are shown in Table 4.

 Table 4--Predicted Radial Distances from R/V Langseth Seismic Source to
         Isopleths Corresponding to Level B Harassment Threshold
------------------------------------------------------------------------
                                                              Predicted
                                                             distance to
                                                Water depth   threshold
               Source and volume                     (m)      (160 dB re
                                                              1 [mu]Pa)
                                                               \1\ (m)
------------------------------------------------------------------------
1 airgun, 40 in\3\............................       >1,000          388
                                                  100-1,000          582
                                                       <100          938
18 airguns, 3,300 in\3\.......................       >1,000        3,562
                                                  100-1,000        5,343
                                                       <100       10,607
36 airguns, 6,600 in\3\.......................       >1,000        5,629
                                                  100-1,000        8,444
                                                       <100       22,102
------------------------------------------------------------------------
\1\ Distances for depths >1,000 m are based on L-DEO model results.
  Distance for depths 100-1,000 m are based on L-DEO model results with
  a 1.5 x correction factor between deep and intermediate water depths.
  Distances for depths <100 m are based on empirically derived
  measurements in the Gulf of Mexico with scaling applied to account for
  differences in tow depth.

    Predicted distances to Level A harassment isopleths, which vary 
based on marine mammal hearing groups, were calculated based on 
modeling performed by L-DEO using the NUCLEUS software program and the 
NMFS User Spreadsheet, described below. The updated acoustic thresholds 
for impulsive sounds (e.g., airguns) contained in the Technical 
Guidance were presented as dual metric acoustic thresholds using both 
SELcum and peak sound pressure metrics (NMFS 2016). As dual 
metrics, NMFS considers onset of PTS (Level A harassment) to have 
occurred when either one of the two metrics is exceeded (i.e., metric 
resulting in the largest isopleth). The SELcum metric 
considers both level and duration of exposure, as well as auditory 
weighting functions by marine mammal hearing group. In recognition of 
the fact that the requirement to calculate Level A harassment 
ensonified areas could be more technically challenging to predict due 
to the duration component and the use of weighting functions in the new 
SELcum thresholds, NMFS developed an optional User 
Spreadsheet that includes tools to help predict a simple isopleth that 
can be used in conjunction with marine mammal density or occurrence to 
facilitate the estimation of take numbers.
    The values for SELcum and peak SPL for the Langseth 
airgun array were derived from calculating the modified farfield 
signature (Table 5). The farfield

[[Page 56133]]

signature is often used as a theoretical representation of the source 
level. To compute the farfield signature, the source level is estimated 
at a large distance below the array (e.g., 9 km), and this level is 
back projected mathematically to a notional distance of 1 m from the 
array's geometrical center. However, when the source is an array of 
multiple airguns separated in space, the source level from the 
theoretical farfield signature is not necessarily the best measurement 
of the source level that is physically achieved at the source (Tolstoy 
et al. 2009). Near the source (at short ranges, distances <1 km), the 
pulses of sound pressure from each individual airgun in the source 
array do not stack constructively, as they do for the theoretical 
farfield signature. The pulses from the different airguns spread out in 
time such that the source levels observed or modeled are the result of 
the summation of pulses from a few airguns, not the full array (Tolstoy 
et al. 2009). At larger distances, away from the source array center, 
sound pressure of all the airguns in the array stack coherently, but 
not within one time sample, resulting in smaller source levels (a few 
dB) than the source level derived from the farfield signature. Because 
the farfield signature does not take into account the large array 
effect near the source and is calculated as a point source, the 
modified farfield signature is a more appropriate measure of the sound 
source level for distributed sound sources, such as airgun arrays. L-
DEO used the acoustic modeling methodology as used for Level B takes 
with a small grid step of 1 m in both the inline and depth directions. 
The propagation modeling takes into account all airgun interactions at 
short distances from the source, including interactions between 
subarrays which are modeled using the NUCLEUS software to estimate the 
notional signature and MATLAB software to calculate the pressure signal 
at each mesh point of a grid.

  Table 5--Modeled Source Levels Based on Modified Farfield Signature for the R/V Langseth 6,600 in \3\ Airgun
                           Array, 3,300 in\3\ Airgun Array, and Single 40 in\3\ Airgun
----------------------------------------------------------------------------------------------------------------
                                                                                      Phocid          Otariid
                                   Low frequency   Mid frequency  High frequency     pinnipeds       pinnipeds
                                     cetaceans       cetaceans       cetaceans     (underwater)    (underwater)
                                  (Lpk,flat: 219  (Lpk,flat: 230  (Lpk,flat: 202  (Lpk,flat: 218  (Lpk,flat: 232
                                  dB; LE,LF,24h:  dB; LE,MF,24h:  dB; LE,HF,24h:  dB; LE,HF,24h:  dB; LE,HF,24h:
                                      183 dB)         185 dB)         155 dB)         185 dB)         203 dB)
 
----------------------------------------------------------------------------------------------------------------
6,600 in\3\ airgun array (Peak            250.77          252.76          249.44          250.50          252.72
 SPLflat).......................
6,600 in\3\ airgun array                  232.75          232.67          232.83          232.67          231.07
 (SELcum).......................
3,300 in\3\ airgun array (Peak            246.34          250.98          243.64          246.03          251.92
 SPLflat).......................
3,300 in\3\ airgun array                  226.22          226.13          226.75          226.13          226.89
 (SELcum).......................
40 in\3\ airgun (Peak SPLflat)..          224.02          225.16          224.00          224.09          226.64
40 in\3\ airgun (SELcum)........          202.33          202.35          203.12          202.35          202.61
----------------------------------------------------------------------------------------------------------------

    In order to more realistically incorporate the Technical Guidance's 
weighting functions over the seismic array's full acoustic band, 
unweighted spectrum data for the Langseth's airgun array (modeled in 1 
hertz (Hz) bands) was used to make adjustments (dB) to the unweighted 
spectrum levels, by frequency, according to the weighting functions for 
each relevant marine mammal hearing group. These adjusted/weighted 
spectrum levels were then converted to pressures ([mu]Pa) in order to 
integrate them over the entire broadband spectrum, resulting in 
broadband weighted source levels by hearing group that could be 
directly incorporated within the User Spreadsheet (i.e., to override 
the Spreadsheet's more simple weighting factor adjustment). Using the 
User Spreadsheet's ``safe distance'' methodology for mobile sources 
(described by Sivle et al., 2014) with the hearing group-specific 
weighted source levels, and inputs assuming spherical spreading 
propagation and source velocities and shot intervals specific to each 
of the three planned surveys (Table 1), potential radial distances to 
auditory injury zones were then calculated for SELcum 
thresholds.
    Inputs to the User Spreadsheets in the form of estimated SLs are 
shown in Table 5. User Spreadsheets used by L-DEO to estimate distances 
to Level A harassment isopleths (SELcum) for the 36-airgun 
array, 18-airgun array, and the single 40 in \3\ airgun for the South 
Island 2-D survey, North Island 2-D survey, and North Island 3-D survey 
are shown in Tables 3, 4, 7, 10, 11, and 12, of the IHA application 
(LGL 2017). Outputs from the User Spreadsheets in the form of estimated 
distances to Level A harassment isopleths for the South Island 2-D 
survey, North Island 2-D survey, and North Island 3-D survey are shown 
in Tables 6, 7 and 8, respectively. As described above, NMFS considers 
onset of PTS (Level A harassment) to have occurred when either one of 
the dual metrics (SELcum and Peak SPLflat) is 
exceeded (i.e., metric resulting in the largest isopleth).

 Table 6--Modeled Radial Distances (m) to Isopleths Corresponding to Level A Harassment Thresholds During North
                                                Island 2-D Survey
----------------------------------------------------------------------------------------------------------------
                                                                                      Phocid          Otariid
                                   Low frequency   Mid frequency  High frequency     pinnipeds       pinnipeds
                                     cetaceans       cetaceans       cetaceans     (underwater)    (underwater)
                                  (Lpk,flat: 219  (Lpk,flat: 230  (Lpk,flat: 202  (Lpk,flat: 218  (Lpk,flat: 232
                                  dB; LE,LF,24h:  dB; LE,MF,24h:  dB; LE,HF,24h:  dB; LE,HF,24h:  dB; LE,HF,24h:
                                      183 dB)         185 dB)         155 dB)         185 dB)         203 dB)
 
----------------------------------------------------------------------------------------------------------------
6,600 in\3\ airgun array (Peak              38.8            13.8           229.2            42.2            10.9
 SPLflat).......................
6,600 in\3\ airgun array                   501.3               0             1.2            13.2               0
 (SELcum).......................
40 in\3\ airgun (Peak SPLflat)..             1.8             0.6            12.6             2.0             0.5
40 in\3\ airgun (SELcum)........             0.4               0               0               0               0
----------------------------------------------------------------------------------------------------------------


[[Page 56134]]


 Table 7--Modeled Radial Distances (m) to Isopleths Corresponding to Level A Harassment Thresholds During North
                                                Island 3-D Survey
----------------------------------------------------------------------------------------------------------------
                                                                                      Phocid          Otariid
                                   Low frequency   Mid frequency  High frequency     Pinnipeds       Pinnipeds
                                     cetaceans       cetaceans       cetaceans     (Underwater)    (Underwater)
                                  (Lpk,flat: 219  (Lpk,flat: 230  (Lpk,flat: 202  (Lpk,flat: 218  (Lpk,flat: 232
                                  dB; LE,LF,24h:  dB; LE,MF,24h:  dB; LE,HF,24h:  dB; LE,HF,24h:  dB; LE,HF,24h:
                                      183 dB)         185 dB)         155 dB)         185 dB)         203 dB)
 
----------------------------------------------------------------------------------------------------------------
3,300 in\3\ airgun array (Peak              23.3            11.2           119.0            25.2             9.9
 SPLflat).......................
3,300 in\3\ airgun array                    73.1               0             0.3             2.8               0
 (SELcum).......................
40 in\3\ airgun (Peak SPLflat)..             1.8             0.6            12.6             2.0             0.5
40 in\3\ airgun (SELcum)........             0.4               0               0               0               0
----------------------------------------------------------------------------------------------------------------


 Table 8--Modeled Radial Distances (m) to Isopleths Corresponding to Level A Harassment Thresholds During South
                                                Island 2-D Survey
----------------------------------------------------------------------------------------------------------------
                                                                                                      Otariid
                                   Low frequency   Mid frequency  High frequency      Phocid         Pinnipeds
                                     cetaceans       cetaceans       cetaceans       Pinnipeds     (Underwater)
                                  (Lpk,flat: 219  (Lpk,flat: 230  (Lpk,flat: 202   (Underwater)   (Lpk,flat: 232
                                  dB; LE,LF,24h:  dB; LE,MF,24h:  dB; LE,HF,24h:  (Lpk,flat: 218      dB; LE,
                                      183 dB)         185 dB)         155 dB)     dB; LE,HF,24h:    HF,24h: 203
                                                                                      185 dB)           dB)
 
----------------------------------------------------------------------------------------------------------------
6,600 in\3\ airgun array (Peak              38.8            13.8           229.2            42.2            10.9
 SPLflat).......................
6,600 in\3\ airgun array                   376.0               0             0.9             9.9               0
 (SELcum).......................
40 in\3\ airgun (Peak SPLflat)..             1.8             0.6            12.6             2.0             0.5
40 in\3\ airgun (SELcum)........             0.3               0               0               0               0
----------------------------------------------------------------------------------------------------------------

    Note that because of some of the assumptions included in the 
methods used, isopleths produced may be overestimates to some degree, 
which will ultimately result in some degree of overestimate of Level A 
take. However, these tools offer the best way to predict appropriate 
isopleths when more sophisticated 3-D modeling methods are not 
available, and NMFS continues to develop ways to quantitatively refine 
these tools and will qualitatively address the output where 
appropriate. For mobile sources, such as the planned seismic surveys, 
the User Spreadsheet predicts the closest distance at which a 
stationary animal would not incur PTS if the sound source traveled by 
the animal in a straight line at a constant speed.

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. The best available scientific information was considered 
in conducting marine mammal exposure estimates (the basis for 
estimating take).
    No systematic aircraft- or ship-based surveys have been conducted 
for marine mammals in offshore waters of the South Pacific Ocean off 
New Zealand that can be used to estimate species densities that we are 
aware of, with the exception of Hector's dolphin surveys that have 
occurred off the South Island. Densities for Hector's dolphins off the 
South Island were estimated using averaged estimated summer densities 
from the most southern stratum of an East Coast South Island survey 
(Otago) and a West Coast South Island survey (Milford Sound), both in 
three offshore strata categories (0-4 nautical miles (nm), 4-12 nm, and 
12-20 nm; MacKenzie and Clement 2014, 2016). The estimated density for 
Hector's dolphins for the South Island 2-D survey was based on the 
proportion of that survey occurring in each offshore stratum.
    For cetacean species other than Hector's dolphin, densities were 
derived from data available for the Southern Ocean (Butterworth et al. 
1994; Kasamatsu and Joyce 1995) (See Table 17 in the IHA application). 
Butterworth et al. (1994) provided comparable data for sei, fin, blue, 
and sperm whales extrapolated to latitudes 30-40[deg] S., 40-50[deg] 
S., and 50-60[deg] S. based on Japanese scouting vessel data from 1965/
66-1977/78 and 1978/79-1987/88. Densities were calculated for these 
species based on abundances and surface areas provided in Butterworth 
et al. (1994) using the mean density for the more recent surveys (1978/
79-1987/88) and the 30-40[deg] S. and 40-50[deg] S. strata, because the 
planned survey areas are between ~37[deg] S. and 50[deg] S. Densities 
were corrected for mean trackline detection probability, g(0) 
availability bias, using mean g(0) values provided for these species 
during NMFS Southwest Fisheries Science Center ship-based surveys 
between 1991-2014 (Barlow 2016). Data for the humpback whale was also 
presented in Butterworth et al. (1994), but, based on the best 
available information, it was determined that the density values 
presented for humpback whales in Butterworth et al. (1994) were likely 
lower than would be expected in the planned survey areas, thus the 
density for humpback whales was ultimately calculated in the same way 
as for the baleen whales for which density data was unavailable. 
Kasamatsu and Joyce (1995) provided data for beaked whales, killer 
whales, long-finned pilot whales, and hourglass dolphins, based on 
surveys conducted as part of the International Whaling Commission/
International Decade of Cetacean Research--Southern Hemisphere Minke 
Whale Assessment, started in 1978/79, and the Japanese sightings survey 
program started in 1976/77. Densities for these species were calculated 
based on abundances and surface areas provided in Kasamatsu and Joyce 
(1995) for Antarctic Areas V EMN and VI WM, which represent the two 
areas reported in Kasamatsu and Joyce (1995) that are nearest to the 
planned South Island survey area. Densities were corrected for 
availability bias using mean g(0) values provided by Kasamatsu and 
Joyce (1995) for beaked whales, killer whales, and long-fined pilot 
whales, and provided by Barlow (2016) for the Hourglass dolphin using 
the mean g(0) calculated for unidentified dolphins during NMFS

[[Page 56135]]

Southwest Fisheries Science Center ship-based surveys between 1991-
2014.
    For the remaining cetacean species, the relative abundances of 
individual species expected to occur in the survey areas were estimated 
within species groups. The relative abundances of these species were 
estimated based on several factors, including information on marine 
mammal observations from areas near the planned survey areas (e.g., 
monitoring reports from previous IHAs (NMFS, 2015); datasets of 
opportunistic sightings (Torres et al., 2014); and analyses of observer 
data from other marine geophysical surveys conducted in New Zealand 
waters (Blue Planet, 2016)), information on latitudinal ranges and 
group sizes of marine mammals in New Zealand waters (e.g., Jefferson et 
al., 2015; NABIS, 2017; Perrin et al., 2009), and other information on 
marine mammals in and near the planned survey areas (e.g., data on 
marine mammal bycatch in New Zealand fisheries (Berkenbush et al., 
2013), data on marine mammal strandings (New Zealand Marine Mammal 
Strandings and Sightings Database); and input from subject matter 
experts (pers. comm., E. Slooten, Univ. of Otago, to H. Goldstein, 
NMFS, April 11, 2015)).
    For each species group (i.e., mysticetes), densities of species for 
which data were available were averaged to get a mean density for the 
group (e.g., densities of fin, sei, and blue whale were averaged to get 
a mean density for mysticetes). Relative abundances of those species 
were then averaged to get mean relative abundances (e.g., relative 
abundance of fin, sei, and blue whale were averaged to get a mean 
relative abundance for mysticetes). For the species for which density 
data was unavailable, their relative abundance score was multiplied by 
the mean density of their respective species group (i.e., relative 
abundance of minke whale was multiplied by mean density for 
mysticetes). The product was then divided by the mean relative 
abundance of the species group to come up with a density estimate. The 
fin, sei, and blue whale densities calculated from Butterworth et al. 
(1994) were proportionally averaged and used to estimate the densities 
of the remaining mysticetes. The sperm whale density calculated from 
Butterworth et al. (1994) was used to estimate the density of the other 
Physeteridae species, the pygmy sperm whale. The hourglass dolphin, 
killer whale, and long-finned pilot whale densities calculated from 
Kasamatsu and Joyce (1995) were proportionally averaged and used to 
estimate the densities of the other Delphinidae for which density data 
was not available. For beaked whales, the beaked whale density 
calculated from Kasamatsu and Joyce (1995) was proportionally allocated 
according to each beaked whale species' estimated relative abundance 
value.
    We are not aware of any information regarding at-sea densities of 
pinnipeds off New Zealand. As such, a surrogate species (northern fur 
seal) was used to estimate offshore pinniped densities for the planned 
surveys. The at-sea density of northern fur seals reported in Bonnell 
et al. (1992), based on systematic aerial surveys conducted in 1989-
1990 in offshore areas off the west coast of the U.S., was used to 
estimate the numbers of pinnipeds that might be present off New 
Zealand. The northern fur seal density reported in Bonnell et al. 
(1992) was used as the New Zealand fur seal density. Densities for the 
other three pinniped species expected to occur in the planned survey 
areas were proportionally allocated relative to the value of the 
density of the northern fur seal, in accordance to the estimated 
relative abundance value of each of the other pinniped species.
    NMFS acknowledges there is some uncertainty related to the 
estimated density data and the assumptions used in their calculations. 
Given the lack of available data on marine mammal density in the 
planned survey areas, the approach used is based on the best available 
data. In recognition of the uncertainties in the density data, we have 
included an additional 25 percent contingency in take estimates to 
account for the fact that density estimates used to estimate take may 
be underestimates of actual densities of marine mammals in the survey 
area. However, there is no information to suggest that the density 
estimates used are in fact underestimates.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate. In order to estimate 
the number of marine mammals predicted to be exposed to sound levels 
that would result in Level A harassment or Level B harassment, radial 
distances from the airgun array to predicted isopleths corresponding to 
the Level A harassment and Level B harassment thresholds are 
calculated, as described above. Those radial distances are then used to 
calculate the area(s) around the airgun array predicted to be 
ensonified to sound levels that exceed the Level A harassment and Level 
B harassment thresholds. The area estimated to be ensonified in a 
single day of the survey is then calculated (Table 9), based on the 
areas predicted to be ensonified around the array and the estimated 
trackline distance traveled per day. This number is then multiplied by 
the number of survey days (i.e., 35 days for the North Island 2-D 
survey, 33 days for the North Island 3-D survey, and 22 days for the 
South Island 2-D survey). The product is then multiplied by 1.25 to 
account for an additional 25 percent contingency for potential 
additional seismic operations (associated with turns, airgun testing, 
and repeat coverage of any areas where initial data quality is sub-
standard, as proposed by L-DEO). This results in an estimate of the 
total areas (km\2\) expected to be ensonified to the Level A harassment 
and Level B harassment thresholds. For purposes of Level B take 
calculations, areas estimated to be ensonified to Level A harassment 
thresholds are subtracted from total areas estimated to be ensonified 
to Level B harassment thresholds in order to avoid double counting the 
animals taken (i.e., if an animal is taken by Level A harassment, it is 
not also counted as taken by Level B harassment). The marine mammals 
predicted to occur within these respective areas, based on estimated 
densities, are assumed to be incidentally taken. The take estimates 
were then multiplied by an additional 25 percent contingency in 
acknowledgement of uncertainties in available density estimates, as 
described above.

[[Page 56136]]



    Table 9--Areas (km \2\) Estimated To Be Ensonified to Level A and Level B Harassment Thresholds per Day for Three Planned Seismic Surveys Off New
                                                                         Zealand
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Level B                            Level A harassment threshold \1\
                                                            harassment   -------------------------------------------------------------------------------
                                                             threshold
                         Survey                          ----------------  Low frequency   Mid frequency       High           Otariid         Phocid
                                                            All marine       cetaceans       cetaceans       frequency       pinnipeds       pinnipeds
                                                              mammals                                        cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Island 2-D Survey.................................         1,931.3           144.5             3.9            65.8             3.1            12.0
North Island 3-D Survey.................................         1,067.3            29.1             4.5            47.5             3.9            10.0
South Island 2-D Survey.................................         1,913.4           111.1             4.1            86.3             3.2            12.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Level A ensonified areas are estimated based on the greater of the distances calculated to Level A isopleths using dual criteria (SELcum and
  peakSPL).
Note: Estimated areas shown for single day do not include additional 50 percent contingency.

    Factors including water depth, array configuration, and proportion 
of each survey occurring within territorial seas (versus within the 
EEZ) were also accounted for in estimates of ensonified areas. This was 
accomplished by selecting a track line for a single day (for each of 
the three planned surveys) that were representative of the entire 
planned survey(s) and using that representative track line to calculate 
daily ensonified areas. Daily track line distance was selected 
depending on array configuration (i.e., 160 km per day for the planned 
2-D surveys, 200 km per day for the planned 3-D survey). Representative 
daily track lines were chosen to reflect the proportion of water depths 
(i.e., less than 100 m, 100-1,000 m, and greater than 1,000 m) expected 
to occur for that entire survey (Table 4) as distances to isopleths 
corresponding to harassment vary depending on water depth (Table 4), 
and water depths vary considerably within the planned survey areas 
(Table 1). Representative track lines were also selected to reflect the 
amount of effort in the New Zealand territorial sea (versus within the 
New Zealand EEZ), for each of the three surveys, as L-DEO is not 
subject to the requirements of the MMPA within the New Zealand 
territorial sea. For example, for the North Island 2-D survey 
approximately nine percent of survey effort would occur in the New 
Zealand territorial sea (Table 1). Thus, representative track lines 
that were chosen also had approximately 9 percent of survey effort in 
territorial seas; the resultant ensonified areas within territorial 
seas were excluded from take calculations.
    Estimated takes for all marine mammal species are shown in Tables 
10, 11, 12 and 13. As described above, we authorize the incidental 
takes that are expected to occur as a result of the planned surveys 
within the New Zealand EEZ but outside of the New Zealand territorial 
sea.

   Table 10--Numbers of Potential Incidental Take of Marine Mammals Authorized During L-DEO's North Island 2-D
                                         Seismic Survey Off New Zealand
----------------------------------------------------------------------------------------------------------------
                                                                                                   Total Level A
                                                    Density (#/    Level A takes   Level B takes    and Level B
                     Species                       1,000 km\2\)   authorized \1\  authorized \1\       takes
                                                                                                  authorized \1\
----------------------------------------------------------------------------------------------------------------
Southern right whale............................            0.24               2              23              25
Pygmy right whale...............................            0.10               1               9              10
Humpback whale..................................            0.24               2              23              25
Bryde's whale...................................            0.14               1              14              15
Common minke whale..............................            0.14               1              14              15
Antarctic minke whale...........................            0.14               1              14              15
Sei whale.......................................            0.14               1              14              15
Fin whale.......................................            0.25               2              24              26
Blue whale......................................            0.04               0               4               4
Sperm whale.....................................            2.89               1             305             306
Cuvier's beaked whale...........................            2.62               1             276             277
Arnoux's beaked whale...........................            2.62               1             276             277
Southern bottlenose whale.......................            1.74               0             184             184
Shepard's beaked whale..........................            1.74               0             184             184
Hector's beaked whale...........................            1.74               0             184             184
True's beaked whale.............................            0.87               0              92              92
Gray's beaked whale.............................            3.49               1             368             369
Andrew's beaked whale...........................            1.74               0             184             184
Strap-toothed whale.............................            2.62               1             276             277
Blainville's beaked whale.......................            0.87               0              92              92
Spade-toothed whale.............................            0.87               0              92              92
Bottlenose dolphin..............................            5.12               1             540             541
Short-beaked common dolphin.....................           10.25               2            1080            1082
Dusky dolphin...................................            5.12               1             540             541
Southern right-whale dolphin....................            3.07               1             324             325
Risso's dolphin.................................            2.05               0             216             216
False killer whale..............................            3.07               1             324             325
Killer whale....................................            1.91               0             202             202
Long-finned pilot whale.........................            8.28               2             872             874
Short-finned pilot whale........................            4.10               1             432             433

[[Page 56137]]

 
Pygmy sperm whale...............................            1.74               6             177             183
Hourglass dolphin...............................            4.16              15             424             439
Hector's dolphin................................               0               0               0               0
Spectacled porpoise.............................               0               0               0               0
New Zealand fur seal............................           22.50               4            2373            2377
New Zealand sea lion............................               0               0               0               0
Southern elephant seal..........................            4.50               3             472             475
Leopard seal....................................            2.25               1             236             237
----------------------------------------------------------------------------------------------------------------
\1\ Includes additional 25 percent contingency for potential additional survey operations and additional 25
  percent contingency to account for uncertainties in density estimates.


   Table 11--Numbers of Potential Incidental Take of Marine Mammals Authorized During L-DEO's North Island 3-D
                                         Seismic Survey Off New Zealand
----------------------------------------------------------------------------------------------------------------
                                                                                                   Total Level A
                                                    Density (#/    Level A takes   Level B takes    and Level B
                     Species                       1,000 km\2\)   authorized \1\  authorized \1\       takes
                                                                                                  authorized \1\
----------------------------------------------------------------------------------------------------------------
Southern right whale............................            0.24               0              13              13
Pygmy right whale...............................            0.10               0               5               5
Humpback whale..................................            0.24               0              13              13
Bryde's whale...................................            0.14               0               8               8
Common minke whale..............................            0.14               0               8               8
Antarctic minke whale...........................            0.14               0               8               8
Sei whale.......................................            0.14               0               8               8
Fin whale.......................................            0.25               0              13              13
Blue whale......................................            0.04               0               2               2
Sperm whale.....................................            2.89               1             159             160
Cuvier's beaked whale...........................            2.62               1             143             144
Arnoux's beaked whale...........................            2.62               1             143             144
Southern bottlenose whale.......................            1.74               0              96              96
Shepard's beaked whale..........................            1.74               0              96              96
Hector's beaked whale...........................            1.74               0              96              96
True's beaked whale.............................            0.87               0              48              48
Gray's beaked whale.............................            3.49               1             191             192
Andrew's beaked whale...........................            1.74               0              96              96
Strap-toothed whale.............................            2.62               1             143             144
Blainville's beaked whale.......................            0.87               0              48              48
Spade-toothed whale.............................            0.87               0              48              48
Bottlenose dolphin..............................            5.12               1             281             282
Short-beaked common dolphin.....................           10.25               2             562             564
Dusky dolphin...................................            5.12               1             281             282
Southern right-whale dolphin....................            3.07               1             168             169
Risso's dolphin.................................            2.05               0             112             112
False killer whale..............................            3.07               1             168             169
Killer whale....................................            1.91               0             105             105
Long-finned pilot whale.........................            8.28               2             454             456
Short-finned pilot whale........................            4.10               1             225             226
Pygmy sperm whale...............................            1.74               4              91              95
Hourglass dolphin...............................            4.16              10             219             229
Hector's dolphin................................               0               0               0               0
Spectacled porpoise.............................               0               0               0               0
New Zealand fur seal............................           22.50               5            1234            1239
New Zealand sea lion............................               0               0               0               0
Southern elephant seal..........................            4.50               2             245             247
Leopard seal....................................            2.25               1             123             124
----------------------------------------------------------------------------------------------------------------
\1\ Includes additional 25 percent contingency for potential additional survey operations and additional 25
  percent contingency to account for uncertainties in density estimates.


[[Page 56138]]


   Table 12--Numbers of Potential Incidental Take of Marine Mammals Authorized During L-DEO's South Island 2-D
                                         Seismic Survey Off New Zealand
----------------------------------------------------------------------------------------------------------------
                                                                                                   Total Level A
                                                    Density (#/    Level A takes   Level B takes    and Level B
                     Species                       1,000 km\2\)   authorized \1\  authorized \1\       takes
                                                                                                  authorized \1\
----------------------------------------------------------------------------------------------------------------
Southern right whale............................            0.24               1              15              16
Pygmy right whale...............................            0.10               0               6               6
Humpback whale..................................            0.24               1              12              13
Bryde's whale...................................            0.14               0               0               0
Common minke whale..............................            0.14               1               9              10
Antarctic minke whale...........................            0.14               1               9              10
Sei whale.......................................            0.14               1               9              10
Fin whale.......................................            0.25               1              15              16
Blue whale......................................            0.04               0               2               2
Sperm whale.....................................            2.89               0             190             190
Cuvier's beaked whale...........................            2.62               0             172             172
Arnoux's beaked whale...........................            2.62               0             172             172
Southern bottlenose whale.......................            1.74               0             114             114
Shepard's beaked whale..........................            1.74               0             114             114
Hector's beaked whale...........................            1.74               0             114             114
True's beaked whale.............................            0.87               0              57              57
Gray's beaked whale.............................            3.49               0             229             229
Andrew's beaked whale...........................            1.74               0             114             114
Strap-toothed whale.............................            2.62               0             172             172
Blainville's beaked whale.......................            0.87               0              57              57
Spade-toothed whale.............................            0.87               0              57              57
Bottlenose dolphin..............................            5.12               1             314             315
Short-beaked common dolphin.....................           10.25               1             314             315
Dusky dolphin...................................            5.12               1             502             503
Southern right-whale dolphin....................            3.07               0             188             188
Risso's dolphin.................................            2.05               0             126             126
False killer whale..............................            3.07               1             188             189
Killer whale....................................            1.91               0             126             126
Long-finned pilot whale.........................            8.28               1             543             544
Short-finned pilot whale........................            4.10               0             126             126
Pygmy sperm whale...............................            1.74               5             109             114
Hourglass dolphin...............................            4.16              12             261             273
Hector's dolphin................................               0               0               2               2
Spectacled porpoise.............................               0               6             120             126
New Zealand fur seal............................           22.50               2            1477            1479
New Zealand sea lion............................               0               1             591             592
Southern elephant seal..........................            4.50               2             294             296
Leopard seal....................................            2.25               1             147             148
----------------------------------------------------------------------------------------------------------------
\1\ Includes additional 25 percent contingency for potential additional survey operations and additional 25
  percent contingency to account for uncertainties in density estimates.


Table 13--Total Numbers of Potential Incidental Take of Marine Mammals Authorized During L-DEO's North Island 3-
       D Survey, North Island 2-D Survey, and South Island 3-D Surveys of the R/V Langseth Off New Zealand
----------------------------------------------------------------------------------------------------------------
                                                                                                       Total
                                                                                                    authorized
                                                                                   Total Level A    Level A and
             Species                Density (#/    Level A takes   Level B takes    and Level B    Level B takes
                                   1,000 km\2\)   authorized \1\  authorized \1\       takes           as a
                                                                                  authorized \1\   percentage of
                                                                                                    population
----------------------------------------------------------------------------------------------------------------
Southern right whale............            0.24               3              51              54            0.45
Pygmy right whale...............            0.10               1              20              21            N.A.
Humpback whale..................            0.19               3              48              51            0.12
Bryde's whale...................            0.00               1              22              23            0.05
Common minke whale..............            0.14               2              31              33           <0.01
Antarctic minke whale...........            0.14               2              31              33           <0.01
Sei whale.......................            0.14               2              31              33            0.33
Fin whale.......................            0.25               3              52              55            0.37
Blue whale......................            0.04               0               8               8            0.21
Sperm whale.....................            2.89               2             654             656            2.19
Cuvier's beaked whale...........            2.62               2             591             593            0.10
Arnoux's beaked whale...........            2.62               2             591             593            0.10
Southern bottlenose whale.......            1.74               0             394             394            0.07
Shepard's beaked whale..........            1.74               0             394             394            0.07
Hector's beaked whale...........            1.74               0             394             394            0.07

[[Page 56139]]

 
True's beaked whale.............            0.87               0             197             197            N.A.
Gray's beaked whale.............            3.49               2             788             790            0.13
Andrew's beaked whale...........            1.74               0             394             394            0.07
Strap-toothed whale.............            2.62               2             591             593            0.10
Blainville's beaked whale.......            0.87               0             197             197            0.03
Spade-toothed whale.............            0.87               0             197             197            0.03
Bottlenose dolphin..............            4.78               3            1135            1138            N.A.
Short-beaked common dolphin.....            4.78               5            1956            1961            N.A.
Dusky dolphin...................            7.65               3            1323            1326           11.05
Southern right-whale dolphin....            2.87               2             680             682            N.A.
Risso's dolphin.................            1.91               0             454             454            N.A.
False killer whale..............            2.87               3             680             683            N.A.
Killer whale....................            1.91               0             433             433            0.54
Long-finned pilot whale.........            8.28               5            1869            1874            0.94
Short-finned pilot whale........            1.91               2             783             785            N.A.
Pygmy sperm whale...............            1.74              15             377             392            N.A.
Hourglass dolphin...............            4.16              37             904             941            0.63
Hector's dolphin................            0.04               0               2               2            0.01
Spectacled porpoise.............            1.91               6             120             126            N.A.
New Zealand fur seal............           22.50              11            5084            5095            2.55
New Zealand sea lion............            9.00               1             591             592            5.99
Southern elephant seal..........            4.50               7            1011            1018            0.17
Leopard seal....................            2.25               3             506             509            0.23
----------------------------------------------------------------------------------------------------------------
\1\ Includes additional 25 percent contingency for potential additional survey operations and additional 25
  percent contingency to account for uncertainties in density estimates.

    As described above, the take estimates shown in Tables 10, 11, 12 
and 13 have been revised slightly since we published the notice of the 
proposed IHA in the Federal Register (82 FR 45116; September 27, 2017). 
Revised take estimates are higher in some cases, and lower in some 
cases, in comparison to the take estimates described in the notice of 
the proposed IHA. These revisions have not affected our preliminary 
determinations.
    It should be noted that the take numbers shown in Tables 10, 11, 12 
and 13 are expected to be conservative for several reasons. First, in 
the calculations of estimated take, 50 percent has been added in the 
form of operational survey days (equivalent to adding 50 percent to the 
line km to be surveyed) to account for the possibility of additional 
seismic operations associated with airgun testing and repeat coverage 
of any areas where initial data quality is sub-standard, and in 
recognition of the uncertainties in the density estimates used to 
estimate take as described above. Additionally, marine mammals would be 
expected to move away from a loud sound source that represents an 
aversive stimulus, such as an airgun array, potentially reducing the 
number of Level A takes. However, the extent to which marine mammals 
would move away from the sound source is difficult to quantify and is 
therefore not accounted for in the take estimates shown in 11, 12, 13 
and 14.
    For some marine mammal species, we authorize a different number of 
incidental takes than the number of incidental takes requested by L-DEO 
(see Tables 18, 19 and 20 in the IHA application for requested take 
numbers). For instance, for several species, L-DEO increased the take 
request from the calculated take number to 1 percent of the estimated 
population size. We do not believe it is likely that 1 percent of the 
estimated population size of those species will be taken by L-DEO's 
planned surveys, therefore we do not authorize the take numbers 
requested by L-DEO in their IHA application (LGL, 2017). However, in 
recognition of the uncertainties in the density estimates used to 
estimate take as described above, we believe it is reasonable to assume 
that actual takes may exceed numbers of takes calculated based on 
available density estimates; therefore, we have increased take 
estimates for all marine mammal species by an additional 25 percent, to 
account for the fact that density estimates used to estimate take may 
be underestimates of actual densities of marine mammals in the survey 
area. Additionally, L-DEO requested authorization for 10 takes of 
Hector's dolphins during the North Island 2-D survey (LGL, 2017). 
However, we do not authorize any takes of Hector's dolphins or Maui 
dolphins during North Island surveys. We believe the likelihood of the 
planned North Island 2-D survey encountering a Hector's dolphin or Maui 
dolphin is so low as to be discountable. As described above, the North 
Island subpopulation of Hector's dolphin (aka Maui dolphin) is very 
unlikely to be encountered during either planned North Island survey 
due to the very low estimated abundance of the subpopulation and due to 
the geographic isolation of the subpopulation (currently limited to the 
west coast of the North Island, whereas all planned North Island 
surveys would occur on the eastern side of the island). As such, we do 
not authorize any takes of Hector's dolphins or Maui dolphins during L-
DEO's planned North Island surveys.

Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such

[[Page 56140]]

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 on 
the availability of such species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned) the likelihood of effective implementation (probability 
implemented as planned), and
    (2) the practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    L-DEO has reviewed mitigation measures employed during seismic 
research surveys authorized by NMFS under previous incidental 
harassment authorizations, as well as recommended best practices in 
Richardson et al. (1995), Pierson et al. (1998), Weir and Dolman 
(2007), Nowacek et al. (2013), Wright (2014), and Wright and Cosentino 
(2015), and has incorporated a suite of proposed mitigation measures 
into their project description based on the above sources.
    To reduce the potential for disturbance from acoustic stimuli 
associated with the activities, L-DEO proposed to implement the 
following mitigation measures for marine mammals:
    (1) Vessel-based visual mitigation monitoring;
    (2) Vessel-based passive acoustic monitoring;
    (3) Establishment of an exclusion zone;
    (4) Power down procedures;
    (5) Shutdown procedures;
    (6) Ramp-up procedures; and
    (7) Vessel strike avoidance measures.
    In addition to the mitigation measures proposed by L-DEO, NMFS has 
incorporated the following additional measures:
    (1) Shutdown upon observation of a large whale with calf at any 
distance;
    (2) Shutdown upon observation of a Hector's dolphin or Maui dolphin 
(during North Island 2-D and North Island 3-D surveys only) at any 
distance;
    (3) Shutdown upon observation of an aggregation (6 or more) of 
large whales of any species at any distance;
    (4) Shutdown upon any observation (visual or acoustic) of a beaked 
whale or Kogia spp. at any distance; and
    (5) Shutdown upon acoustic detection of a sperm whale (with certain 
exceptions) at any distance.
    As described above, measures (3), (4) and (5) incorporated by NMFS 
above were added to the suite of mitigation measures after we published 
the notice of the proposed IHA in the Federal Register (82 FR 45116; 
September 27, 2017), in response to comments received from the 
Commission.

Vessel-Based Visual Mitigation Monitoring

    Protected Species Observer (PSO) observations will take place 
during all daytime airgun operations and nighttime start ups (if 
applicable) of the airguns. Airgun operations will be suspended when 
marine mammals are observed within, or about to enter, designated 
Exclusion Zones (as described below). PSOs will also watch for marine 
mammals near the vessel for at least 30 minutes prior to the planned 
start of airgun operations. PSOs will monitor the entire extent of the 
modeled Level B harassment zone (Table 3) (or, as far as they are able 
to see, if they cannot see to the extent of the estimated Level B 
harassment zone). Observations will also be made during daytime periods 
when the Langseth is underway without seismic operations, such as 
during transits, to allow for comparison of sighting rates and behavior 
with and without airgun operations and between acquisition periods.
    During seismic operations, a minimum of four visual PSOs will be 
based aboard the Langseth. PSOs will be appointed by L-DEO, with NMFS' 
approval. During the majority of seismic operations, two PSOs will 
monitor for marine mammals around the seismic vessel. Use of two 
simultaneous observers increases the effectiveness of detecting marine 
mammals around the source vessel. However, during meal times, only one 
PSO may be on duty. PSO(s) will be on duty in shifts of duration no 
longer than 4 hours. Other crew will also be instructed to assist in 
detecting marine mammals and in implementing mitigation requirements 
(if practical). Before the start of the seismic survey, the crew will 
be given additional instruction in detecting marine mammals and 
implementing mitigation requirements. The Langseth is a suitable 
platform for marine mammal observations. When stationed on the 
observation platform, PSOs will have a good view around the entire 
vessel. During daytime, the PSO(s) will scan the area around the vessel 
systematically with reticle binoculars (e.g., 7 x 50 Fujinon), Big-eye 
binoculars (25 x 150), and with the naked eye.
    The PSOs must have no tasks other than to conduct observational 
effort, record observational data, and communicate with and instruct 
relevant vessel crew with regard to the presence of marine mammals and 
mitigation requirements. PSO resumes will be provided to NMFS for 
approval. At least two PSOs must have a minimum of 90 days at-sea 
experience working as PSOs during a high energy seismic survey, with no 
more than eighteen months elapsed since the conclusion of the at-sea 
experience. One ``experienced'' visual PSO will be designated as the 
lead for the entire protected species observation team. The lead will 
coordinate duty schedules and roles for the PSO team and serve as 
primary point of contact for the vessel operator. The lead PSO will 
devise the duty schedule such that ``experienced'' PSOs are on duty 
with those PSOs with appropriate training but who have not yet gained 
relevant experience, to the maximum extent practicable.
    The PSOs must have successfully completed relevant training, 
including completion of all required coursework and passing a written 
and/or oral examination developed for the training program, and must 
have successfully attained a bachelor's degree from an accredited 
college or university with a major in one of the natural sciences and a 
minimum of 30 semester hours or equivalent in the biological sciences 
and at least one undergraduate course in math or statistics. The 
educational requirements may be waived if the PSO has acquired the 
relevant skills through alternate training, including (1) secondary 
education and/or experience

[[Page 56141]]

comparable to PSO duties; (2) previous work experience conducting 
academic, commercial, or government-sponsored marine mammal surveys; or 
(3) previous work experience as a PSO. The PSO should demonstrate good 
standing and consistently good performance of PSO duties.

Vessel-Based Passive Acoustic Mitigation Monitoring

    Passive acoustic monitoring (PAM) will take place to complement the 
visual monitoring program and to inform mitigation measures. Visual 
monitoring typically is not effective during periods of poor visibility 
or at night, and even with good visibility, is unable to detect marine 
mammals when they are below the surface or beyond visual range. 
Acoustic monitoring can be used in addition to visual observations to 
improve detection, identification, and localization of cetaceans. The 
acoustic monitoring will serve to inform mitigation measures and to 
alert visual observers (if on duty) when vocalizing cetaceans are 
detected. PAM is only useful when marine mammals vocalize, but it can 
be effective either by day or by night and does not depend on good 
visibility. PAM will be monitored in real time so that visual observers 
can be alerted when marine mammals are detected acoustically.
    The PAM system consists of hardware (i.e., hydrophones) and 
software. The ``wet end'' of the system consists of a towed hydrophone 
array that is connected to the vessel by a tow cable. A deck cable will 
connect the tow cable to the electronics unit on board where the 
acoustic station, signal conditioning, and processing system will be 
located. The acoustic signals received by the hydrophones are 
amplified, digitized, and then processed by the software.
    At least one acoustic PSO (in addition to the four visual PSOs) 
will be on board. The towed hydrophones will be monitored 24 hours per 
day (either by the acoustic PSO or by a visual PSO trained in the PAM 
system if the acoustic PSO is on break) while at the seismic survey 
area during airgun operations, and during most periods when the 
Langseth is underway while the airguns are not operating. However, PAM 
may not be possible if damage occurs to the array or back-up systems 
during operations. One PSO will monitor the acoustic detection system 
at any one time, in shifts no longer than six hours, by listening to 
the signals via headphones and/or speakers and watching the real-time 
spectrographic display for frequency ranges produced by cetaceans.
    When a vocalization is detected, the acoustic PSO will take 
necessary action depending on the species and location of the animal 
detected. If the species and/or location of the animal(s) warrants 
immediate shutdown of the array, the acoustic PSO will contact the 
vessel operator immediately to call for a shutdown (see the section on 
Mitigation, below, for scenarios that require shutdown based on 
acoustic detection), If the species and/or location of the animal(s) 
does not warrant immediate shutdown, the acoustic PSO will contact 
visual PSOs immediately, to alert them to the presence of marine 
mammals (if they have not already been detected visually), in order to 
facilitate a power down or shutdown, if required. The information 
regarding the marine mammal acoustic detection will be entered into a 
database.
    In summary, a typical daytime cruise will have scheduled two 
observers (visual) on duty from the observation platform, and an 
acoustic observer on the passive acoustic monitoring system.

Exclusion Zone and Buffer Zone

    An exclusion zone (EZ) is a defined area within which occurrence of 
a marine mammal triggers mitigation action intended to reduce the 
potential for certain outcomes, e.g., auditory injury, disruption of 
critical behaviors. The PSOs will establish a minimum EZ with a 500 m 
radius for the 36 airgun array and the 18 airgun array. The 500 m EZ 
will be based on radial distance from any element of the airgun array 
(rather than being based on the center of the array or around the 
vessel itself). With certain exceptions (described below), if a marine 
mammal appears within, enters, or appears on a course to enter this 
zone, the acoustic source will be powered down (see Power Down 
Procedures below). In addition to the 500 m EZ for the full arrays, a 
100 m exclusion zone will be established for the single 40 in\3\ 
airgun. With certain exceptions (described below), if a marine mammal 
appears within, enters, or appears on a course to enter this zone the 
acoustic source will be shut down entirely (see Shutdown Procedures 
below). Additionally, power down of the full arrays will last no more 
than 30 minutes maximum at any given time; thus the arrays will be shut 
down entirely if, after 30 minutes of the array being powered down, a 
marine mammal remains inside the 500 m EZ (with the exception of 
spectacled porpoise and bottlenose, hourglass, and Hector's dolphins, 
as described above).
    In their IHA application, L-DEO proposed to establish EZs based 
upon modeled radial distances to auditory injury zones (e.g., power 
down would occur when a marine mammal entered or appeared likely to 
enter the zone(s) within which auditory injury is expected to occur 
based on modeling) (Tables 6, 7, 8). However, we instead require the 
500 m EZ as described above. The 500 m EZ is intended to be 
precautionary in the sense that it would be expected to contain sound 
exceeding peak pressure injury criteria for all cetacean hearing 
groups, while also providing a consistent, reasonably observable zone 
within which PSOs would typically be able to conduct effective 
observational effort. Additionally, a 500-m EZ is expected to minimize 
the likelihood that marine mammals will be exposed to levels likely to 
result in more severe behavioral responses. Although significantly 
greater distances may be observed from an elevated platform under good 
conditions, we believe that 500 m is likely regularly attainable for 
PSOs using the naked eye during typical conditions.
    An appropriate EZ based on cumulative sound exposure level 
(SELcum) criteria would be dependent on the animal's applied 
hearing range and how that overlaps with the frequencies produced by 
the sound source of interest (i.e., via marine mammal auditory 
weighting functions) (NMFS, 2016), and may be larger in some cases than 
the zones calculated on the basis of the peak pressure thresholds (and 
larger than 500 m) depending on the species in question and the 
characteristics of the specific airgun array. In particular, the EZ 
radii would be larger for low-frequency cetaceans, because their most 
susceptible hearing range overlaps the low frequencies produced by 
airguns, but the zones would remain very small for mid-frequency 
cetaceans (i.e., including the ``small delphinoids'' described below), 
whose range of best hearing largely does not overlap with frequencies 
produced by airguns.
    Use of monitoring and shutdown or power-down measures within 
defined exclusion zone distances is inherently an essentially 
instantaneous proposition--a rule or set of rules that requires 
mitigation action upon detection of an animal. This indicates that 
definition of an exclusion zone on the basis of cumulative sound 
exposure level thresholds, which require that an animal accumulate some 
level of sound energy exposure over some period of time (e.g., 24 
hours), has questionable relevance as a standard protocol. A PSO aboard 
a mobile source will typically have no ability to monitor an animal's 
position relative to the acoustic source

[[Page 56142]]

over relevant time periods for purposes of understanding whether 
auditory injury is likely to occur on the basis of cumulative sound 
exposure and, therefore, whether action should be taken to avoid such 
potential.
    Cumulative SEL thresholds are more relevant for purposes of 
modeling the potential for auditory injury than they are for dictating 
real-time mitigation, though they can be informative (especially in a 
relative sense). We recognize the importance of the accumulation of 
sound energy to an understanding of the potential for auditory injury 
and that it is likely that, at least for low-frequency cetaceans, some 
potential auditory injury is likely impossible to mitigate and should 
be considered for authorization.
    In summary, our intent in prescribing a standard exclusion zone 
distance is to (1) encompass zones for most species within which 
auditory injury could occur on the basis of instantaneous exposure; (2) 
provide additional protection from the potential for more severe 
behavioral reactions (e.g., panic, antipredator response) for marine 
mammals at relatively close range to the acoustic source; (3) provide 
consistency for PSOs, who need to monitor and implement the exclusion 
zone; and (4) to define a distance within which detection probabilities 
are reasonably high for most species under typical conditions.
    Our use of 500 m as the EZ is a reasonable combination of factors. 
This zone is expected to contain all potential auditory injury for all 
marine mammals (high-frequency, mid-frequency and low-frequency 
cetacean functional hearing groups and otariid and phocid pinnipeds) as 
assessed against peak pressure thresholds (NMFS, 2016) (Tables 6, 7, 
8). It is also expected to contain all potential auditory injury for 
high-frequency and mid-frequency cetaceans as well as otariid and 
phocid pinnipeds as assessed against SELcum thresholds 
(NMFS, 2016) (Tables 6, 7, 8). It has proven to be practicable through 
past implementation in seismic surveys conducted for the oil and gas 
industry in the Gulf of Mexico (as regulated by the Bureau of Ocean 
Energy Management (BOEM) pursuant to the Outer Continental Shelf Lands 
Act (43 U.S.C. 1331-1356)). In summary, a practicable criterion, such 
as the EZs described above, has the advantage of simplicity while still 
providing in most cases a zone larger than relevant auditory injury 
zones, given realistic movement of source and receiver.
    The PSOs will also establish and monitor a 500 m buffer zone (i.e., 
500 m in addition to the 500 m EZ). During operation of the airgun 
arrays, occurrence of marine mammals within the 500 m buffer zone (but 
outside the 500 m EZ) will be communicated to the vessel operator to 
prepare for potential power down or shutdown of the acoustic source. 
The buffer zone is discussed further under Ramp Up Procedures below. 
PSOs will also monitor the entire extent of the estimated Level B 
harassment zone (Table 3) (or, as far as they are able to see, if they 
cannot see to the extent of the estimated Level B harassment zone).

Power Down Procedures

    A power down involves decreasing the number of airguns in use such 
that the smallest single element of the array is in operation (i.e., 
one 40-in\3\ airgun), with the result that the radius of the mitigation 
zone is decreased to the extent that marine mammals are no longer in, 
or about to enter, the 500 m EZ. The continued operation of one 40-
in\3\ airgun is intended to alert marine mammals to the presence of the 
seismic vessel in the area, and to allow them to leave the area of the 
seismic vessel if they choose. In contrast, a shutdown occurs when all 
airgun activity is suspended (shutdown procedures are discussed below). 
If a marine mammal is detected outside the 500 m EZ but appears likely 
to enter the 500 m EZ, the array will be powered down before the animal 
is within the 500 m EZ. Likewise, if a mammal is already within the 500 
m EZ when first detected, the array will be powered down immediately. 
During a power down of the airgun array, the 40-in\3\ airgun will be 
operated.
    Following a power down, airgun activity will not resume until the 
marine mammal has cleared the 500 m EZ. The animal will be considered 
to have cleared the 500 m EZ if the following conditions have been met:
     It is visually observed to have departed the 500 m EZ; or
     it has not been seen within the 500 m EZ for 15 min in the 
case of small odontocetes and pinnipeds; or
     it has not been seen within the 500 m EZ for 30 min in the 
case of mysticetes and large odontocetes, including sperm, pygmy sperm, 
dwarf sperm, and beaked whales.
    This power down requirement will be in place for all marine 
mammals, with the exception of certain small delphinoids under certain 
circumstances. As defined here, the small delphinoid group is intended 
to encompass those members of the Family Delphinidae most likely to 
voluntarily approach the source vessel for purposes of interacting with 
the vessel and/or airgun array (e.g., bow riding). This exception to 
the power down requirement applies solely to specific species of small 
dolphins: Short-beaked common dolphin, dusky dolphin, and southern 
right whale dolphin. If there is uncertainty regarding identification 
(i.e., whether the observed animal(s) belongs to the species described 
above), the power down or shutdown must be implemented. Note that 
bottlenose, hourglass, and Hector's dolphins and spectacled porpoise 
are not included in the power down/shutdown exception.
    We include this small delphinoid exception because power-down/
shutdown requirements for small delphinoids under all circumstances 
represent practicability concerns without likely commensurate benefits 
for the animals in question. Small delphinoids are generally the most 
commonly observed marine mammals in the specific geographic region and 
would typically be the only marine mammals likely to intentionally 
approach the vessel. As described below, auditory injury is extremely 
unlikely to occur for mid-frequency cetaceans (e.g., delphinids), as 
this group is relatively insensitive to sound produced at the 
predominant frequencies in an airgun pulse while also having a 
relatively high threshold for the onset of auditory injury (i.e., 
permanent threshold shift). Please see Potential Effects of the 
Specified Activity on Marine Mammals in the Federal Register notice of 
the proposed IHA (82 FR 45116; September 27, 2017) for further 
discussion of sound metrics and thresholds and marine mammal hearing. 
Bottlenose dolphins are excluded from the power down waiver due to 
concerns from the New Zealand Department of Conservation, while 
hourglass, spectacled, and Hector's dolphins are excluded from the 
power down waiver due to their functional hearing range (they are 
classified as high frequency cetaceans which would make them more 
susceptible to harassment or possible injury as a result of exposure to 
airgun sounds).
    A large body of anecdotal evidence indicates that small delphinoids 
commonly approach vessels and/or towed arrays during active sound 
production for purposes of bow riding, with no apparent effect observed 
in those delphinoids (e.g., Barkaszi et al., 2012). The potential for 
increased shutdowns resulting from such a measure would require the 
Langseth to revisit the missed track line to reacquire data, resulting 
in an overall increase in the total sound energy input to the marine 
environment and an increase in

[[Page 56143]]

the total duration over which the survey is active in a given area. 
Although other mid-frequency hearing specialists (e.g., large 
delphinoids) are no more likely to incur auditory injury than are small 
delphinoids, they are much less likely to approach vessels. Therefore, 
retaining a power-down/shutdown requirement for large delphinoids would 
not have similar impacts in terms of either practicability for the 
applicant or corollary increase in sound energy output and time on the 
water. We do anticipate some benefit for a power-down/shutdown 
requirement for large delphinoids in that it simplifies somewhat the 
total range of decision-making for PSOs and may preclude any potential 
for physiological effects other than to the auditory system as well as 
some more severe behavioral reactions for any such animals in close 
proximity to the source vessel.
    A power down could occur for no more than 30 minutes maximum at any 
given time. If, after 30 minutes of the array being powered down, 
marine mammals had not cleared the 500 m EZ (as described above), a 
shutdown of the array will be implemented (see Shut Down Procedures, 
below). Power down is only allowed in response to the presence of 
marine mammals within the designated EZ. Thus, the single 40 in\3\ 
airgun, which will be operated during power downs, may not be operated 
continuously throughout the night or during transits from one line to 
another.

Shut Down Procedures

    The single 40-in\3\ operating airgun will be shut down if a marine 
mammal is seen within or approaching the 100 m EZ for the single 40-
in\3\ airgun. Shutdown will be implemented if (1) an animal enters the 
100 m EZ of the single 40-in\3\ airgun after a power down has been 
initiated, or (2) an animal is initially seen within the 100 m EZ of 
the single 40-in\3\ airgun when more than one airgun (typically the 
full array) is operating. Airgun activity will not resume until the 
marine mammal has cleared the 500 m EZ. Criteria for judging that the 
animal has cleared the EZ will be as described above. A shutdown of the 
array will be implemented if, after 30 minutes of the array being 
powered down, marine mammals have not cleared the 500 m EZ (as 
described above).
    The shutdown requirement, like the power down requirement, is 
waived for dolphins of the following species: Short-beaked common 
dolphin, dusky dolphin and southern right whale dolphin. If there is 
uncertainty regarding identification (i.e., whether the observed 
animal(s) belongs to the species described above), the shutdown will be 
implemented.
    Other Shutdown Requirements--In addition to the shutdown 
requirement described above, NMFS also requires shutdown of the 
acoustic source in the event of certain other observations regardless 
of the defined exclusion zone. While visual PSOs should focus 
observational effort within the vicinity of the acoustic source and 
vessel (i.e., approximately 1 km radius), this does not preclude them 
from periodic scanning of the remainder of the visible area, and there 
is no reason to believe that such periodic scans by professional PSOs 
would hamper their ability to maintain observation of areas closer to 
the source and vessel. These circumstances include:
     Upon observation of a large whale (i.e., sperm whale or 
any baleen whale) with calf at any distance, with ``calf'' defined as 
an animal less than two-thirds the body size of an adult observed to be 
in close association with an adult. Groups of whales are likely to be 
more susceptible to disturbance when calves are present (e.g., Bauer et 
al., 1993), and disturbance of cow-calf pairs could potentially result 
in separation of vulnerable calves from adults. McCauley et al. (2000a) 
found that groups of humpback whale females with calves consistently 
avoided a single operating airgun, while male humpbacks were attracted 
to it, concluding that cow-calf pairs are more likely to exhibit 
avoidance responses to unfamiliar sounds and that such responses should 
be a focus of management. Behavioral disturbance has been implicated in 
mother-calf separations for odontocete species as well (Noren and 
Edwards, 2007; Wade et al., 2012). Separation, if it occurred, could be 
exacerbated by airgun signals masking communication between adults and 
the separated calf (Videsen et al., 2017). Absent separation, airgun 
signals can disrupt or mask vocalizations essential to mother-calf 
interactions. Reductions in the probability of calf survival for gray 
whales have been linked to airgun surveys in Russia (Cooke et al., 
2016).
     Upon acoustic detection of a sperm whale (except in cases 
where the location of an acoustically detected sperm whale can be 
definitively localized as outside the 500 m EZ). Sperm whales are not 
necessarily expected to display physical avoidance of sound sources 
(e.g., Madsen et al., 2002a; Jochens et al., 2008; Winsor et al., 
2017). Although Winsor et al. (2017) report that distances and 
orientations between tagged whales and active airgun arrays appeared to 
be randomly distributed with no evidence of horizontal avoidance, it 
must be noted that their study was to some degree precipitated by an 
earlier observation of significantly decreased sperm whale density in 
the presence of airgun surveys (Mate et al., 1994). However, effects on 
vocal behavior are common (e.g., Watkins and Schevill, 1975; Watkins et 
al., 1985). The sperm whale's primary means of locating prey is 
echolocation (Miller et al., 2004), and multiple studies have shown 
that noise can disrupt feeding behavior and/or significantly reduce 
foraging success for sperm whales at relatively low levels of exposure 
(e.g., Miller et al., 2009, 2012; Isojunno et al., 2016; Sivle et al., 
2012; Cure et al., 2016). Effects on energy intake with no immediate 
compensation, as is suggested by disruption of foraging behavior 
without corollary movements to new locations, would be expected to 
result in bioenergetics consequences to individual whales.
    We also considered requirement of shutdown upon visual detection of 
sperm whales at any distance. Here, we assume that acoustic detections 
of sperm whales would most likely be representative of the foraging 
behavior we intend to minimize disruption of, while visual observations 
of sperm whales would represent resting between bouts of such behavior. 
Occurrence of resting sperm whales at distances beyond the exclusion 
zone may not indicate a need to implement shutdown. If the location of 
an acoustically detected sperm whale can be definitively localized by 
the PAM operator as outside the 500 m EZ, then the requirement to 
shutdown the array is waived. If there is any uncertainty as to whether 
or not an acoustically detected sperm whale is within the 500 m EZ, 
shutdown must be implemented.
     Upon any observation (visual or acoustic) of a beaked 
whale or Kogia spp. These species are behaviorally sensitive deep 
divers and it is possible that disturbance could provoke a severe 
behavioral response leading to injury (e.g., Wursig et al., 1998; Cox 
et al., 2006). Unlike the sperm whale, we recognize that there are 
generally low detection probabilities for beaked whales and Kogia spp., 
meaning that many animals of these species may go undetected. Barlow 
(1999) estimates such probabilities at 0.23 to 0.45 for Cuvier's and 
Mesoplodont beaked whales, respectively. However, Barlow and Gisiner 
(2006) predict a roughly 24-48 percent reduction in the probability of 
detecting beaked whales during seismic mitigation monitoring efforts as 
compared with typical research survey

[[Page 56144]]

efforts, and Moore and Barlow (2013) noted a decrease in g(0) for 
Cuvier's beaked whales from 0.23 at BSS 0 (calm) to 0.024 at BSS 5. 
Similar detection probabilities have been noted for Kogia spp., though 
they typically travel in smaller groups and are less vocal, thus making 
detection more difficult (Barlow and Forney, 2007). Because it is 
likely that only a small proportion of beaked whales and Kogia spp. 
potentially affected by the planned surveys would actually be detected, 
it is important to avoid potential impacts when possible.
     Upon visual observation of an aggregation (6 or more) of 
large whales of any species (i.e., sperm whale or any baleen whale) 
(e.g., feeding, socializing, etc.). Under these circumstances, we 
assume that the animals are engaged in some important behavior (e.g., 
feeding, socializing) that should not be disturbed. By convention, we 
define an aggregation as six or more animals.
     Upon observation (visual or acoustic) of a Hector's 
dolphin or Maui dolphin (during North Island and South Island surveys) 
at any distance. As described above, the Maui dolphin is considered one 
of the rarest dolphins in the world with a population size estimated at 
just 63 individuals (Baker et al. 2016). It has undergone a marked 
reduction in range (Dawson et al. 2001; Slooten et al. 2005), and 
currently faces a high risk of extinction (Manning and Grantz, 2016). 
The shutdown requirement for Hector's/Maui dolphin during North Island 
surveys is designed to avoid any potential for exposure of a Maui 
dolphin to seismic airgun sounds. Maui dolphins are not expected to 
occur in the planned survey areas off the North Island based on their 
current range. However, as described above, there have been occasional 
sightings of Hector's dolphins off the east coast of the North Island 
though it is unclear whether those individuals may have originated from 
the South Island Hector's dolphin populations (Baker 1978, Russell 
1999, Ferreira and Roberts 2003, Slooten et al. 2005, DuFresne 2010, 
Berkenbusch et al. 2013; Torres et al. 2013; Pati[ntilde]o-P[eacute]rez 
2015; NZDOC 2017). While we have determined the likelihood of L-DEO's 
planned North Island surveys encountering a Hector's dolphin or Maui 
dolphin is extremely low, we nonetheless include this measure to 
further minimize the already extremely unlikely potential for exposure 
of a Maui dolphin to airgun sounds. Also as described above, Hector's 
dolphins have relatively small home ranges and high site fidelity and a 
genetically distinct and localized population occurs in Te Waewae Bay 
(Mackenzie and Clement, 2014). Due to the limited range and high site 
fidelity of the population of Hector's dolphin that occurs in Te Waewae 
Bay and the proximity of the planned South Island 2-D survey with Te 
Waewae Bay we have included this requirement to protect the South 
Island Hector's dolphin. The requirement to shut down on acoustic 
detection applies when the acoustic detection can be positively 
identified as originating from a Hector's dolphin.
     In the event of a shutdown due to visual observation of a 
beaked whale, Kogia spp., an aggregation of large whales, or large 
whale with calf, ramp-up procedures will not be initiated until the 
animal(s) that triggered the shutdown has not been seen at any distance 
for 30 minutes. In the event of a shutdown due to visual or confirmed 
acoustic detection of a Hector's or Maui dolphin, ramp-up procedures 
will not be initiated until the Hector's/Maui dolphin has not been 
visually or acoustically detected at any distance for 15 minutes. In 
the event of a shutdown due to acoustic detection of a sperm whale, 
Kogia spp., or beaked whale, ramp-up procedures will not be initiated 
until the animal(s) that triggered the shutdown has not been detected 
acoustically for 30 minutes.

Ramp-Up Procedures

    Ramp-up of an acoustic source is intended to provide a gradual 
increase in sound levels following a power down or shutdown, enabling 
animals to move away from the source if the signal is sufficiently 
aversive prior to its reaching full intensity. The ramp-up procedure 
involves a step-wise increase in the number of airguns firing and total 
array volume until all operational airguns are activated and the full 
volume is achieved. Ramp-up is required after the array is powered down 
or shut down due to mitigation. If the airgun array has been shut down 
for reasons other than mitigation (e.g., mechanical difficulty) for a 
period of less than 30 minutes, it may be activated again without ramp-
up if PSOs have maintained constant visual and acoustic observation and 
no visual detections of any marine mammal have occurred within the 
buffer zone and no acoustic detections have occurred. This is the only 
scenario under which ramp up is not required.
    Ramp-up will begin by activating a single airgun of the smallest 
volume in the array and will continue in stages by doubling the number 
of active elements at the commencement of each stage, with each stage 
of approximately the same duration.
    If airguns have been powered down or shut down due to PSO detection 
of a marine mammal within or approaching the 500 m EZ, ramp-up will not 
be initiated until all marine mammals have cleared the EZ, during the 
day or night. Visual and acoustic PSOs are required to monitor during 
ramp-up. If a marine mammal were detected by visual PSOs within or 
approaching the 500 m EZ during ramp-up, a power down (or shut down if 
appropriate) will be implemented as though the full array were 
operational. Criteria for clearing the EZ will be as described above.
    Thirty minutes of pre-clearance observation of the 500 m EZ and 500 
m buffer zone are required prior to ramp-up following any extended 
deactivation of the array (i.e., if the array were shut down during 
transit from one line to another). This 30 minute pre-clearance period 
may occur during any vessel activity (i.e., transit). If a marine 
mammal is observed within or approaching the 500 m EZ during this pre-
clearance period, ramp-up will not be initiated until all marine 
mammals have cleared the EZ. Criteria for clearing the EZ will be as 
described above.
    Ramp-up will be planned to occur during periods of good visibility 
when possible. However, ramp-up is allowed at night and during poor 
visibility if the 500 m EZ and 500 m buffer zone have been monitored by 
visual PSOs for 30 minutes prior to ramp-up and if acoustic monitoring 
has occurred for 30 minutes prior to ramp-up with no acoustic 
detections during that period. Ramp-up of the array may not occur at 
night or during poor visibility if the PAM system is not functional.
    The operator is required to notify a designated PSO of the planned 
start of ramp-up as agreed-upon with the lead PSO. A designated PSO 
must be notified again immediately prior to initiating ramp-up 
procedures and the operator must receive confirmation from the PSO to 
proceed. The operator must provide information to PSOs documenting that 
appropriate procedures were followed. Following deactivation of the 
array for reasons other than mitigation, the operator is required to 
communicate the near-term operational plan to the lead PSO with 
justification for any planned nighttime ramp-up.
    L-DEO proposed that ramp up would not occur following an extended 
power down (LGL 2017). However, as we do not allow extended power downs 
during the planned surveys, we also do not include this as a mitigation 
measure; instead, ramp up is required after any power down or shutdown 
of the array (with the one exception as described above). L-DEO also 
proposed that ramp up would occur when the airgun array begins 
operating after 8 minutes without

[[Page 56145]]

airgun operations (LGL 2017). However, we instead include the criteria 
for ramp-up as described above.

Vessel Strike Avoidance

    Vessel strike avoidance measures are intended to minimize the 
potential for collisions with marine mammals. We note that these 
requirements do not apply in any case where compliance would create an 
imminent and serious threat to a person or vessel or to the extent that 
a vessel is restricted in its ability to maneuver and, because of the 
restriction, cannot comply.
    The vessel strike avoidance measures include the following: Vessel 
operator and crew will maintain a vigilant watch for all marine mammals 
and slow down or stop the vessel or alter course to avoid striking any 
marine mammal. A visual observer aboard the vessel will monitor a 
vessel strike avoidance zone around the vessel according to the 
parameters stated below. Visual observers monitoring the vessel strike 
avoidance zone will be either third-party observers or crew members, 
but crew members responsible for these duties will be provided 
sufficient training to distinguish marine mammals from other phenomena. 
Vessel strike avoidance measures will be followed during surveys and 
while in transit.
    The vessel will maintain a minimum separation distance of 100 m 
from large whales (i.e., baleen whales and sperm whales). If a large 
whale is within 100 m of the vessel the vessel will reduce speed and 
shift the engine to neutral, and will not engage the engines until the 
whale has moved outside of the vessel's path and the minimum separation 
distance has been established. If the vessel is stationary, the vessel 
will not engage engines until the whale(s) has moved out of the 
vessel's path and beyond 100 m. The vessel will maintain a minimum 
separation distance of 50 m from all other marine mammals (with the 
exception of short-beaked common dolphins, dusky dolphins and southern 
right whale dolphins that approach the vessel, as described above). If 
an animal is encountered during transit, the vessel will attempt to 
remain parallel to the animal's course, avoiding excessive speed or 
abrupt changes in course. Vessel speeds will be reduced to 10 knots or 
less when mother/calf pairs, pods, or large assemblages of cetaceans 
are observed near the vessel.
    Based on our evaluation of the applicant's proposed measures, NMFS 
has determined that the mitigation measures provide the means of 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Monitoring and Reporting

    In order to issue an IHA 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 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
action area. Effective reporting is critical both to compliance as well 
as ensuring that the most value is obtained from the required 
monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.
    L-DEO submitted a marine mammal monitoring and reporting plan in 
section XIII of their IHA application. Monitoring that is designed 
specifically to facilitate mitigation measures, such as monitoring of 
the EZ to inform potential power downs or shutdowns of the airgun 
array, are described above.
    L-DEO's monitoring and reporting plan includes the following 
measures:

Vessel-Based Visual Monitoring

    As described above, PSO observations will take place during daytime 
airgun operations and nighttime start ups (if applicable) of the 
airguns. During seismic operations, at least four visual PSOs will be 
based aboard the Langseth. PSOs will be appointed by L-DEO with NMFS 
approval. During the majority of seismic operations, two PSOs will 
monitor for marine mammals around the seismic vessel. Use of two 
simultaneous observers increases the effectiveness of detecting animals 
around the source vessel. However, during meal times, only one PSO may 
be on duty. PSOs will be on duty in shifts of duration no longer than 4 
hours. Other crew will also be instructed to assist in detecting marine 
mammals and in implementing mitigation requirements (if practical). 
During daytime, PSOs will scan the area around the vessel 
systematically with reticle binoculars (e.g., 7 x 50 Fujinon), Big-eye 
binoculars (25 x 150), and with the naked eye.
    PSOs will record data to estimate the numbers of marine mammals 
exposed to various received sound levels and to document apparent 
disturbance reactions or lack thereof. Data will be used to estimate 
numbers of animals potentially `taken' by harassment (as defined in the 
MMPA). They will also provide information needed to order a power down 
or shutdown of airguns when a marine mammal is within or near the EZ.
    When a sighting is made, the following information about the 
sighting will be recorded:
    1. Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from seismic vessel, sighting cue, 
apparent reaction to the airguns or vessel (e.g., none, avoidance, 
approach, paralleling, etc.), and behavioral pace; and
    2. Time, location, heading, speed, activity of the vessel, sea 
state, visibility, and sun glare.
    All observations and power downs or shutdowns will be recorded in a 
standardized format. Data will be entered into an electronic database. 
The accuracy of the data entry will be verified by computerized data 
validity checks as the data are entered and by subsequent manual 
checking of the database. These procedures will allow

[[Page 56146]]

initial summaries of data to be prepared during and shortly after the 
field program and will facilitate transfer of the data to statistical, 
graphical, and other programs for further processing and archiving. The 
time, location, heading, speed, activity of the vessel, sea state, 
visibility, and sun glare will also be recorded at the start and end of 
each observation watch, and during a watch whenever there is a change 
in one or more of the variables.
    Results from the vessel-based observations will provide:
    1. The basis for real-time mitigation (airgun power down or 
shutdown);
    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 seismic study is conducted;
    4. Information to compare the distance and distribution of marine 
mammals relative to the source vessel at times with and without seismic 
activity; and
    5. Data on the behavior and movement patterns of marine mammals 
seen at times with and without seismic activity.

Vessel-Based Passive Acoustic Monitoring

    As described above, the acoustic PSO will monitor the PAM system in 
real time. When a vocalization is detected, the acoustic PSO will take 
necessary action depending on the species and location of the animal 
detected, whether immediately calling for a shutdown or immediately 
contacting visual PSOs to alert them to the presence of marine mammals 
in order to facilitate a power down or shutdown, if required.
    PAM will also take place to complement the visual monitoring 
program as described above. Please see the Mitigation section above for 
a description of the PAM system and the acoustic PSO's duties. The 
acoustic PSO will record data collected via the PAM system, including 
the following: An acoustic encounter identification number, whether it 
was linked with a visual sighting, date, time when first and last heard 
and whenever any additional information was recorded, position and 
water depth when first detected, bearing if determinable, species or 
species group (e.g., unidentified dolphin, sperm whale), types and 
nature of sounds heard (e.g., clicks, continuous, sporadic, whistles, 
creaks, burst pulses, strength of signal, etc.), and any other notable 
information. Acoustic detections will also be recorded for further 
analysis.

Reporting

    A report will be submitted to NMFS within 90 days after the end of 
the cruise. The report will describe the operations that were conducted 
and sightings of marine mammals near the operations. The report will 
provide full documentation of methods, results, and interpretation 
pertaining to all monitoring. The 90-day report will summarize the 
dates and locations of seismic operations, and all marine mammal 
sightings (dates, times, locations, activities, associated seismic 
survey activities). The report will also include estimates of the 
number and nature of exposures that occurred above the harassment 
threshold based on PSO observations, including an estimate of those on 
the trackline but not detected.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact 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 (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 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 harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, our analysis applies to all the species listed 
in Table 2, given that NMFS expects the anticipated effects of the 
planned seismic surveys to be similar in nature. Where there are 
meaningful differences between species or stocks, or groups of species, 
in anticipated individual responses to activities, impact of expected 
take on the population due to differences in population status, or 
impacts on habitat, NMFS has identified species-specific factors to 
inform the analysis. As described above, we authorize only the takes 
estimated to occur outside of New Zealand territorial sea (Tables 10, 
11, 12 and 13); however, for the purposes of our negligible impact 
analysis and determination, we consider the total impacts to the 
affected marine mammal populations resulting from the specified 
activity, including takes that are expected to occur within the 
territorial sea (Table 14).

Table 14--Total Numbers of Potential Incidental Take of Marine Mammals During Portions of L-DEO's North Island 2-
         D, North Island 3-D, and South Island 2-D Surveys That Occur in the New Zealand Territorial Sea
----------------------------------------------------------------------------------------------------------------
                                                                                                       Total
                                                                     Estimated       Estimated       estimated
                             Species                               Level A takes   Level B takes    Level A and
                                                                        \1\             \1\        Level B takes
                                                                                                        \1\
----------------------------------------------------------------------------------------------------------------
Southern right whale............................................               0              25              25
Pygmy right whale...............................................               0              11              11
Humpback whale..................................................               0              24              24
Bryde's whale...................................................               0              14              14
Common minke whale..............................................               0              16              16
Antarctic minke whale...........................................               0              16              16
Sei whale.......................................................               0              16              16

[[Page 56147]]

 
Fin whale.......................................................               0              25              25
Blue whale......................................................               0               6               6
Sperm whale.....................................................               0             278             278
Cuvier's beaked whale...........................................               0             251             251
Arnoux's beaked whale...........................................               0             251             251
Southern bottlenose whale.......................................               0             169             169
Shepard's beaked whale..........................................               0             169             169
Hector's beaked whale...........................................               0             169             169
True's beaked whale.............................................               0              85              85
Gray's beaked whale.............................................               0             334             334
Andrew's beaked whale...........................................               0             169             169
Strap-toothed whale.............................................               0             251             251
Blainville's beaked whale.......................................               0              85              85
Spade-toothed whale.............................................               0              85              85
Bottlenose dolphin..............................................               0             486             486
Short-beaked common dolphin.....................................               0             918             918
Dusky dolphin...................................................               0             518             518
Southern right-whale dolphin....................................               0             291             291
Risso's dolphin.................................................               0             195             195
False killer whale..............................................               0             291             291
Killer whale....................................................               0             184             184
Long-finned pilot whale.........................................               0             789             789
Short-finned pilot whale........................................               0             368             368
Pygmy sperm whale...............................................               1             166             167
Hourglass dolphin...............................................               3             394             397
Hector's dolphin................................................               0               1               1
Spectacled porpoise.............................................               0              21              21
New Zealand fur seal............................................               0            2141            2141
New Zealand sea lion............................................               0              98              98
Southern elephant seal..........................................               0              69              69
Leopard seal....................................................               0              35              35
----------------------------------------------------------------------------------------------------------------
Note: NMFS does not authorize the estimated takes shown in the territorial sea.
\1\ Includes additional 25 percent contingency for potential additional survey operations and additional 25
  percent contingency to account for uncertainties in density estimates.

    NMFS does not anticipate that serious injury or mortality will 
occur as a result of L-DEO's planned surveys, even in the absence of 
mitigation. As discussed in the Potential Effects section, non-auditory 
physical effects, stranding, and vessel strike are not expected to 
occur.
    We authorize a limited number of instances of Level A harassment of 
21 marine mammal species (Tables 10, 11, 12 and 13). However, we 
believe that any PTS incurred in marine mammals as a result of the 
planned activity would be in the form of only a small degree of PTS, 
not severe hearing impairment, and would be unlikely to affect the 
fitness of any individuals, because of the constant movement of both 
the Langseth and of the marine mammals in the project area, as well as 
the fact that the vessel is not expected to remain in any one area in 
which individual marine mammals would be expected to concentrate for an 
extended period of time (i.e., since the duration of exposure to loud 
sounds will be relatively short). Also, as described above, we expect 
that marine mammals would be likely to move away from a sound source 
that represents an aversive stimulus, especially at levels that would 
be expected to result in PTS, given sufficient notice of the Langseth's 
approach due to the vessel's relatively low speed when conducting 
seismic surveys. We expect that the majority of takes would be in the 
form of short-term Level B behavioral harassment in the form of 
temporary avoidance of the area or decreased foraging (if such activity 
were occurring), reactions that are considered to be of low severity 
and with no lasting biological consequences (e.g., Southall et al., 
2007).
    Potential impacts to marine mammal habitat are discussed in the 
Federal Register notice of the proposed IHA (82 FR 45116; September 27, 
2017) and are summarized below. Marine mammal habitat may be impacted 
by elevated sound levels, but these impacts would be temporary. Feeding 
behavior is not likely to be significantly impacted, as marine mammals 
appear to be less likely to exhibit behavioral reactions or avoidance 
responses while engaged in feeding activities (Richardson et al., 
1995). Prey species are mobile and are broadly distributed throughout 
the project area; therefore, marine mammals that may be temporarily 
displaced during survey activities are expected to be able to resume 
foraging once they have moved away from areas with disturbing levels of 
underwater noise. Because of the temporary nature of the disturbance, 
the availability of similar habitat and resources in the surrounding 
area, and the lack of important or unique marine mammal habitat, the 
impacts to marine mammals and the food sources that they utilize are 
not expected to cause significant or long-term consequences for 
individual marine mammals or their populations. In addition, there are 
no mating or calving areas known to be biologically important to marine 
mammals within the proposed project area.
    Prey species are mobile and are broadly distributed throughout the

[[Page 56148]]

project area; therefore, marine mammals that may be temporarily 
displaced during survey activities are expected to be able to resume 
foraging once they have moved away from areas with disturbing levels of 
underwater noise. Because of the temporary nature of the disturbance, 
the availability of similar habitat and resources in the surrounding 
area, and the lack of important or unique marine mammal habitat, the 
impacts to marine mammals and the food sources that they utilize are 
not expected to cause significant or long-term consequences for 
individual marine mammals or their populations. In addition, there are 
no mating or calving areas known to be biologically important to marine 
mammals within the planned project area.
    As described above, the take estimates shown in Tables 10, 11, 12 
and 13 have been revised slightly since we published the notice of the 
proposed IHA in the Federal Register (82 FR 45116; September 27, 2017). 
We have fully considered these revised take estimates in our negligible 
impact analysis. Additionally, the acoustic ``footprint'' of the 
planned surveys is small relative to the ranges of the marine mammals 
potentially be affected. Sound levels would increase in the marine 
environment in a relatively small area surrounding the vessel compared 
to the range of the marine mammals within the planned survey area.
    The mitigation measures are expected to reduce the number and/or 
severity of takes by allowing for detection of marine mammals in the 
vicinity of the vessel by visual and acoustic observers, and by 
minimizing the severity of any potential exposures via power downs and/
or shutdowns of the airgun array. Based on previous monitoring reports 
for substantially similar activities that have been previously 
authorized by NMFS, we expect that the mitigation will be effective in 
preventing at least some extent of potential PTS in marine mammals that 
may otherwise occur in the absence of the mitigation.
    The ESA-listed marine mammal species under our jurisdiction that 
are likely to be taken by the planned surveys include the southern 
right, sei, fin, blue, and sperm whale (listed as endangered) and the 
South Island Hector's dolphin (listed as threatened). We authorize a 
very limited amount of take for these species (Tables 10, 11, 12 and 
13), relative to their population sizes, therefore we do not expect 
population-level impacts to any of these species. The other marine 
mammal species that may be taken by harassment during the planned 
surveys are not listed as threatened or endangered under the ESA. There 
is no designated critical habitat for any ESA-listed marine mammals 
within the project area; and of the non-listed marine mammals for which 
we authorize take, none are considered ``depleted'' or ``strategic'' by 
NMFS under the MMPA.
    NMFS concludes that exposures to marine mammal species and stocks 
due to L-DEO's planned survey would result in only short-term 
(temporary and short in duration) effects to individuals exposed. 
Animals may temporarily avoid the immediate area, but are not expected 
to permanently abandon the area. Major shifts in habitat use, 
distribution, or foraging success are not expected.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the marine mammal species or 
stocks through effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized;
     The anticipated impacts of the planned activity on marine 
mammals would primarily be temporary behavioral changes due to 
avoidance of the area around the survey vessel;
     The number of instances of PTS that may occur are expected 
to be very small in number (Tables 10, 11, 12 and 13). Instances of PTS 
that are incurred in marine mammals would be of a low level, due to 
constant movement of the vessel and of the marine mammals in the area, 
and the nature of the survey design (not concentrated in areas of high 
marine mammal concentration);
     The availability of alternate areas of similar habitat 
value for marine mammals to temporarily vacate the survey area during 
the planned surveys to avoid exposure to sounds from the activity;
     The planned project area does not contain known areas of 
significance for mating or calving;
     The potential adverse effects on fish or invertebrate 
species that serve as prey species for marine mammals from the planned 
surveys would be temporary and spatially limited; and
     The mitigation measures, including visual and acoustic 
monitoring, power downs, and shutdowns, are expected to minimize 
potential impacts to marine mammals.
    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 monitoring and mitigation 
measures, NMFS finds that the total marine mammal take from the planned 
activity will have a negligible impact on all affected marine mammal 
species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers; so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. Additionally, other qualitative factors may 
be considered in the analysis, such as the temporal or spatial scale of 
the activities. Tables 10, 11, 12 and 13 provide numbers of take by 
Level A harassment and Level B harassment authorized. These are the 
numbers we use for purposes of the small numbers analysis.
    The numbers of marine mammals that we authorize to be taken would 
be considered small relative to the relevant populations (less than 12 
percent for all species) for the species for which abundance estimates 
are available. No known current worldwide or regional population 
estimates are available for ten species under NMFS' jurisdiction that 
could be incidentally taken as a result of the planned surveys: the 
pygmy right whale; pygmy sperm whale; True's beaked whale; short-finned 
pilot whale; false killer whale; bottlenose dolphin; short-beaked 
common dolphin; southern right whale dolphin; Risso's dolphin; and 
spectacled porpoise.
    NMFS has reviewed the geographic distributions and habitat 
preferences of these species in determining whether the numbers of 
takes authorized herein are likely to represent small numbers. Pygmy 
right whales have a circumglobal distribution and occur throughout 
coastal and oceanic waters in the Southern Hemisphere (between 30 to 
55[deg] South) (Jefferson et al., 2008). Pygmy sperm whales occur in 
deep waters on the outer continental shelf and slope in tropical to 
temperate waters of the Atlantic, Indian, and Pacific Oceans. True's 
beaked whales occur in the Southern hemisphere from the western 
Atlantic Ocean to the Indian Ocean to the waters of southern Australia 
and possibly New Zealand (Jefferson et al., 2008). False killer whales 
generally occur in deep offshore tropical to temperate waters (between

[[Page 56149]]

50[deg] North to 50[deg] South) of the Atlantic, Indian, and Pacific 
Oceans (Jefferson et al., 2008). Southern right whale dolphins have a 
circumpolar distribution and generally occur in deep temperate to sub-
Antarctic waters in the Southern Hemisphere (between 30 to 65[deg] 
South) (Jefferson et al., 2008). Short-finned pilot whales are found in 
warm temperate to tropical waters throughout the world, generally in 
deep offshore areas (Olson and Reilly, 2002). Bottlenose dolphins are 
distributed worldwide through tropical and temperate inshore, coastal, 
shelf, and oceanic waters (Leatherwood and Reeves 1990, Wells and Scott 
1999, Reynolds et al. 2000). Spectacled porpoises are believed to have 
a range that is circumpolar in the sub-Antarctic zone (with water 
temperatures of at least 1-10 [deg]C) (Goodall 2002). The Risso's 
dolphin is a widely-distributed species, inhabiting primarily deep 
waters of the continental slope and outer shelf (especially with steep 
bottom topography), from the tropics through the temperate regions in 
both hemispheres (Kruse et al. 1999). The short-beaked common dolphin 
is an oceanic species that is widely distributed in tropical to cool 
temperate waters of the Atlantic and Pacific Oceans (Perrin 2002), from 
nearshore waters to thousands of kilometers offshore.
    Based on the broad spatial distributions and habitat preferences of 
these species relative to the areas where the planned surveys are 
planned to occur, NMFS concludes that the authorized take of these 
species likely represent small numbers relative to the affected 
species' overall population sizes, though we are unable to quantify the 
take numbers as a percentage of population.
    Based on the analysis contained herein of the planned activity 
(including the mitigation and monitoring measures) and the anticipated 
take of marine mammals, NMFS finds that small numbers of marine mammals 
will be taken relative to the population size of the affected species.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks will not 
have an unmitigable adverse impact on the availability of such species 
or stocks for taking for subsistence purposes.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally, in this case with the ESA Interagency 
Cooperation Division, whenever we propose to authorize take for 
endangered or threatened species.
    The NMFS Permits and Conservation Division is authorizing the 
incidental take of six species of marine mammals which are listed under 
the ESA (the southern right, sei, fin, blue, and sperm whale and South 
Island Hector's dolphin). Under section 7 of the ESA, we initiated 
consultation with the NMFS OPR Interagency Cooperation Division for the 
issuance of this IHA. In October, 2017, the NMFS OPR Interagency 
Cooperation Division issued a Biological Opinion with an incidental 
take statement, which concluded that the issuance of the IHA was not 
likely to jeopardize the continued existence of the southern right, 
sei, fin, blue, and sperm whale and South Island Hector's dolphin. The 
Biological Opinion also concluded that the issuance of the IHA would 
not destroy or adversely modify designated critical habitat for these 
species.

Authorization

    NMFS has issued an IHA to the L-DEO for the potential harassment of 
small numbers of 38 marine mammal species incidental to marine 
geophysical surveys in the southwest Pacific Ocean, provided the 
previously mentioned mitigation, monitoring and reporting requirements 
are incorporated.

    Dated: November 21, 2017.
Donna Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2017-25516 Filed 11-24-17; 8:45 am]
 BILLING CODE 3510-22-P