[Federal Register Volume 83, Number 221 (Thursday, November 15, 2018)]
[Notices]
[Pages 57432-57453]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-24977]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG559


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Boost-Back and Landing of Falcon 9 
Rockets

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request from Space Exploration Technology 
Corporation (SpaceX) for authorization to take marine mammals 
incidental to boost-back and landing of Falcon 9 rockets at Vandenberg 
Air Force Base (VAFB) in California, and at contingency landing 
locations in the Pacific Ocean. Pursuant to the Marine Mammal 
Protection Act (MMPA), NMFS is requesting comments on its proposal to 
issue an incidental harassment authorization (IHA) to incidentally take 
marine mammals during the specified activities. NMFS is also requesting 
comments on a possible one-year renewal that could be issued under 
certain circumstances and if all requirements are met, as described in 
Request for Public Comments at the end of this notice. NMFS will 
consider public comments prior to making any final decision on the 
issuance of the requested MMPA authorizations and agency responses will 
be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than December 
17, 2018.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-research-and-other-activities without change. All 
personal identifying information (e.g., name, address) voluntarily 
submitted by the commenter may be publicly accessible. Do not submit 
confidential business information or otherwise sensitive or protected 
information.

FOR FURTHER INFORMATION CONTACT: Amy Fowler, 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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-research-and-other-activities. In case of problems 
accessing these documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION: 

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. 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 incidental take authorization may be provided to the public 
for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other means of effecting the least practicable adverse 
impact on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of such takings are set forth.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (incidental harassment authorizations with 
no anticipated serious injury or mortality) of the Companion Manual for 
NOAA Administrative Order 216-6A, which do not individually or 
cumulatively have the potential for significant impacts on the quality 
of the human environment and for which we have not identified any 
extraordinary circumstances that would preclude this categorical 
exclusion. Accordingly, NMFS has preliminarily determined that the 
issuance of the proposed IHA qualifies to be categorically excluded 
from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process

[[Page 57433]]

or making a final decision on the IHA request.

Summary of Request

    On August 30, 2018, NMFS received a request from SpaceX for an IHA 
to take marine mammals incidental to Falcon 9 First Stage recovery 
activities, including in-air boost-back maneuvers and landings of the 
First Stage of the Falcon 9 rocket at VAFB in California, and at 
contingency landing locations offshore. A revised application was 
received October 23, 2018. NMFS deemed that request to be adequate and 
complete. SpaceX's request is for take of a small number of six species 
by Level B harassment only. Neither SpaceX nor NMFS expects serious 
injury or mortality to result from this activity and, therefore, an IHA 
is appropriate.
    NMFS has previously issued regulations and Letters of Authorization 
(LOA) that authorize the take of marine mammals, by Level B harassment, 
incidental to launches of up to 50 rockets per year (including the 
Falcon 9) from VAFB (79 FR 18528; April 2, 2014). The regulations, 
titled Taking of Marine Mammals Incidental to U.S. Air Force Launches, 
Aircraft and Helicopter Operations, and Harbor Activities Related to 
Vehicles from Vandenberg Air Force Base, California, published February 
24, 2014, are effective from March 2014 to March 2019. The activities 
proposed by SpaceX are limited to Falcon 9 First Stage recovery events 
(Falcon 9 boost-back maneuvers and landings); launches of the Falcon 9 
rocket are not part of the proposed activities, and incidental take 
(Level B harassment) resulting from Falcon 9 rocket launches from VAFB 
is already authorized in the above referenced LOA. As such, NMFS does 
not propose to authorize take of marine mammals incidental to launches 
of the Falcon 9 rocket in this IHA; incidental take resulting from 
Falcon 9 rocket launches is therefore not analyzed further in this 
document. The LOA application (USAF 2013a), and links to the Federal 
Register notice of the final rule (79 FR 10016; February 24, 2014) and 
the Federal Register notice of issuance of the LOA (79 FR 18528; April 
2, 2014), can be found online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. After the expiration of the existing LOA 
for VAFB, NMFS anticipates that the entire suite of SpaceX's Falcon 9 
activities at VAFB (Falcon 9 rocket launches and First Stage boost-
backs and landings) will be incorporated into future authorizations for 
VAFB.
    Additionally, NMFS has previously issued two IHAs to SpaceX for 
similar activities (81 FR 34984, June 1, 2016; 82 FR 60954, December 
26, 2017). SpaceX complied with all the requirements (e.g., mitigation, 
monitoring, and reporting) of the previous IHAs and information 
regarding their monitoring results may be found in the Estimated Take 
section.

Description of Proposed Activity

Overview

    The Falcon 9 is a two-stage rocket designed and manufactured by 
SpaceX for transport of satellites and SpaceX's Dragon spacecraft into 
orbit. SpaceX currently operates the Falcon Launch Vehicle Program at 
Space Launch Complex 4 East (SLC-4E) at VAFB. SpaceX proposes regular 
employment of First Stage recovery by returning the Falcon 9 First 
Stage to SLC-4 West (SLC-4W) at VAFB for potential reuse, up to twelve 
times per year. This includes performing boost-back maneuvers (in-air) 
and landings of the Falcon 9 First Stage on the pad at SLC-4W. The 
reuse of the Falcon 9 First Stage enables SpaceX to efficiently conduct 
lower cost launch missions from VAFB in support of commercial and 
government clients.
    During descent, a sonic boom (overpressure of high-energy impulsive 
sound) would be generated when the First Stage reaches a rate of travel 
that exceeds the speed of sound. Sonic booms would occur in proximity 
to the landing areas and may be heard during or after the boost-back 
and landing, depending on the location of the observer. Sound from the 
sonic boom would have the potential to result in harassment of marine 
mammals, either on the mainland at or near VAFB or at the Northern 
Channel Islands (NCI), as described in more detail later in this 
document.

Dates and Duration

    SpaceX's activities are conducted throughout the year. Up to twelve 
Falcon 9 First Stage recovery activities would occur per year. Precise 
dates of Falcon 9 First Stage recovery activities are not known. Falcon 
9 First Stage recovery activities may take place at any time of year 
and at any time of day. The IHA, if issued, would be valid for one year 
from the date of issuance.

Specific Geographic Region

    Falcon 9 First Stage recovery activities will originate at VAFB. 
Areas potentially affected include VAFB, areas on the coastline 
surrounding VAFB, and the NCI. VAFB operates as a missile test base and 
aerospace center, supporting west coast space launch activities for the 
U.S. Air Force (USAF), Department of Defense, National Aeronautics and 
Space Administration, and commercial contractors. VAFB is the main west 
coast launch facility for placing commercial government, and military 
satellites into polar orbit on expendable (unmanned) launch vehicles, 
and for testing and evaluating intercontinental ballistic missiles and 
sub-orbital target and interceptor missiles.
    VAFB occupies approximately 99,100 acres of central Santa Barbara 
County, California. VAFB is divided by the Santa Ynez River and State 
Highway 246 into two distinct parts: North Base and South Base. SLC-4W, 
the preferred landing location for the Falcon 9 First Stage, is located 
on South Base, approximately 0.5 miles (mi) (0.8 kilometers (km)) 
inland from the Pacific Ocean (see Figure 1-2 in the IHA application). 
SLC-4E, the launch facility for SpaceX's Falcon 9 program, is located 
approximately 715 feet (ft) (218 meters (m)) to the east of SLC-4W.
    Although SLC-4W is the preferred landing location for the Falcon 9 
First Stage, SpaceX has identified two contingency landing locations 
should it not be feasible to land the First Stage at SLC-4W. The first 
contingency landing location is on a barge located at least 27 nautical 
miles (nmi) (50 km) offshore of VAFB. The second contingency landing 
location is on a barge within the Iridium Landing Area, an 
approximately 12,800 square mile (mi\2\) (33,153 square kilometers 
(km\2\)) area located approximately 122 nmi (225 km) southwest of San 
Nicolas Island and 133 nmi (245 km) southwest of San Clemente Island 
(see Figure 1-3 in the IHA application). The NCI are also considered 
part of the project area for the purposes of this proposed 
authorization, as landings at VAFB could result in sonic booms that 
impact the NCI. The NCI are four islands (San Miguel, Santa Rosa, Santa 
Cruz, and Anacapa) located approximately 31 mi (50 km) south of Point 
Conception, which is located on the mainland approximately 4 mi (6.5 
km) south of the southern border of VAFB. The closest part of the NCI 
to VAFB (Harris Point on San Miguel Island) is located more than 34 mi 
(55 km) south-southeast of SLC-4E, the launch facility for the Falcon 9 
rocket.

Detailed Description of Specific Activity

    The Falcon 9 is a two-stage rocket designed and manufactured by 
SpaceX for transport of satellites into orbit. The First Stage of the 
Falcon 9 is designed to be reusable, while the second stage is not 
reusable. The Falcon 9 First Stage is

[[Page 57434]]

12 ft (3.7 m) in diameter and 160 ft (48.8 m) in height, including the 
interstage that would remain attached during landing. The proposed 
action includes up to twelve Falcon 9 First Stage recoveries, including 
in-air boost-back maneuvers and landings of the First Stage, at VAFB or 
at a contingency landing location as described above.
    After launch of the Falcon 9, the boost-back and landing sequence 
begins when the rocket's First Stage separates from the second stage 
and the Merlin engines of the First Stage cut off. After First Stage 
engine cutoff, rather than dropping the First Stage in the Pacific 
Ocean, exoatmospheric cold gas thrusters would be triggered to flip the 
First Stage into position for retrograde burn. Three of the nine First 
Stage Merlin engines would be restarted to conduct the retrograde burn 
in order to reduce the velocity of the First Stage and to place the 
First Stage in the correct angle to land. Once the First Stage is in 
position and approaching its landing target, the three engines would 
cut off to end the boost-back burn. The First Stage would then perform 
a controlled descent using atmospheric resistance to slow the stage 
down and guide it to the landing pad target. The First Stage is 
outfitted with grid fins that allow cross range corrections as needed. 
The landing legs on the First Stage would then deploy in preparation 
for a final single engine burn that would slow the First Stage to a 
velocity of zero before landing on the landing pad at SLC-4W.

Sonic Boom

    During descent, a sonic boom (overpressure of high-energy impulsive 
sound) would be generated when the First Stage reaches a rate of travel 
that exceeds the speed of sound. Sonic booms would occur in proximity 
to the landing area with the highest sound levels generated from sonic 
booms generally focused in the direction of the landing area, and may 
be heard during or briefly after the boost-back and landing, depending 
on the location of the receiver. Sound from the sonic booms would have 
the potential to result in harassment of marine mammals, as described 
in greater detail later in this document. Based on model results, a 
boost-back and landing of the Falcon 9 First Stage at SLC-4W would 
produce sonic booms with overpressures that would potentially be as 
high as 8.5 pounds per square foot (psf) at VAFB and potentially as 
high as 3.1 psf at the NCI (see Figures 2-2 and 2-5 in the IHA 
application). Sonic boom modeling indicates that landings that occur at 
either of the proposed contingency landing locations offshore would 
result in sonic booms with received overpressures below 1.0 psf at VAFB 
and the NCI. Take of pinnipeds that are hauled out of the water are 
expected to occur only when those hauled out pinnipeds experience sonic 
booms greater than 1.0 psf (discussed in greater detail below in the 
Estimated Take section). Therefore, take of marine mammals may occur as 
a result of landings that occur at VAFB; however, take of marine 
mammals is not expected to occur as a result of landings that occur at 
either of the proposed contingency landing locations offshore. Please 
see Figure 1-4 in the IHA application for a graphical depiction of the 
boost-back and landing sequence, and see Figure 1-5 in the IHA 
application for an example of the boost-back trajectory of the First 
Stage and the second stage trajectory.
    As a contingency action to landing the Falcon 9 First Stage on the 
SLC-4W pad at VAFB, SpaceX proposes to return the Falcon 9 First Stage 
booster to a barge in the Pacific Ocean (Figure 1-6 in the IHA 
application). The maneuvering and landing process described above for a 
pad landing would be the same for a barge landing. Three vessels would 
be required to support a barge landing, if it were required: A barge/
landing platform (300 ft (91 m) long and 150 ft (46 m) wide); a support 
vessel (165 ft (50 m) long research vessel); and an ocean tug (120 ft 
(37 m) long open water commercial tug).

Landing Noise

    Landing noise would be generated during each boost-back event. 
SpaceX proposes to use a three-engine burn during landing. This engine 
burn, lasting approximately 17 seconds, would generate noise between 70 
and 110 decibels (dB) re 20 micro Pascals ([micro]Pa) (non-pulse, in-
air noise) centered on SLC-4W, but affecting an area up to 15 nmi (27.8 
km) offshore of VAFB (Figure 2-10 in the IHA application). This landing 
noise event would be of short duration (approximately 17 seconds). 
Although, during a landing event at SLC-4W, landing noise between 70 
and 90 dB would be expected to overlap pinniped haulout areas at and 
near Point Arguello and Purisima Point, no pinniped haulouts would 
experience landing noises of 90 dB or greater (see Figure 2-10 in the 
IHA application).
    NMFS's recommended acoustic thresholds for in-air acoustic impacts 
assume that Level B harassment of harbor seals may occur at 90 dB root 
mean square (rms) re 20 [micro]Pa and Level B harassment of all other 
pinnipeds may occur at 100 dB rms re 20 [micro]Pa. Therefore, 
harassment of marine mammals hauled out at VAFB from engine noise 
generated during landings is not expected to occur. Engine noise would 
also be produced during a contingency barge landing of the Falcon 9 
First Stage. Engine noise during a barge landing is expected to be 
between 70 and 110 dB re 20 [micro]Pa affecting a radial area up to 15 
nmi (27.8 km) around the contingency landing location (Figure 2-11 in 
the IHA application) and the Iridium 38 Landing Area (Figure 2-12 in 
the IHA application). No pinniped haulouts are located within the areas 
predicted to experience engine noise of 90 dB and above during Falcon 9 
First Stage landings at contingency landing locations and the Iridium 
Landing Area (Figures 2-11 and 2-12 in the IHA application). Therefore, 
the likelihood of engine noise associated with the landing of the 
Falcon 9 First Stage resulting in take of marine mammals is considered 
so low as to be discountable, and landing noise is therefore not 
discussed further in this document.

Unsuccessful Barge Landing

    In the event of an unsuccessful barge landing, the First Stage 
would explode upon impact with the barge. The direct sound from an 
explosion would last less than a second. Furthermore, the proposed 
activities would be dispersed in time, with maximum of twelve barge 
landing attempts occurring within a twelve month time period. If an 
explosion occurred on the barge, as in the case of an unsuccessful 
barge landing attempt, some amount of the explosive energy would be 
transferred through the ship's structure and would enter the water and 
propagate away from the ship.
    There is very little published literature on the ratio of explosive 
energy that is absorbed by a ship's hull versus the amount of energy 
that is transferred through the ship into the water. However, based on 
the best available information, we have determined that exceptionally 
little of the acoustic energy from the explosion would transmit into 
the water (Yagla and Stiegler, 2003). An explosion on the barge would 
create an in-air blast that propagates away in all directions, 
including toward the water's surface; however the barge's deck would 
act as a barrier that would attenuate the energy directed downward 
toward the water (Yagla and Stiegler, 2003). Most sound enters the 
water in a narrow cone beneath the sound source (within 13 degrees of 
vertical) (National Research Council 2003). Since the explosion

[[Page 57435]]

would occur on the barge, most of this sound would be reflected by the 
barge's surface, and sound waves would approach the water's surface at 
angles higher than 13 degrees, minimizing transmission into the ocean. 
An explosion on the barge would also send energy through the barge's 
structure, into the water, and away from the barge. This effect was 
investigated in conjunction with the measurements described in Yagla 
and Steigler (2003). Yagla and Steigler (2003) reported that the energy 
transmitted through a ship to the water for the firing of a typical 5-
inch round was approximately six percent of that from the in-air blast 
impinging on the water (Yagla and Stiegler, 2003). Therefore, sound 
transmitted from the blast through the hull into the water was a 
minimal component of overall firing noise, and would likewise be 
expected to be a minimal component of an explosion occurring on the 
surface of the barge.
    Depending on the amount of fuel remaining in the booster at the 
time of the explosion, the intensity of the explosion would likely 
vary. Based on previous Falcon 9 boost-back and landing activities, the 
explosive equivalence of the First Stage with maximum fuel and oxidizer 
would be expected to be approximately 500 lb. of trinitrotoluene (TNT). 
Explosion shock theory has proposed specific relationships for the peak 
pressure and time constant in terms of the charge weight and range from 
the detonation position (Pater 1981; Plotkin et al. 2012). For an in-
air explosion equivalent to 500 lb. of TNT, at 0.5 ft the explosion 
would be approximately 250 dB re 20 [micro]Pa. Based on the assumption 
that the structure of the barge would absorb and reflect approximately 
94 percent of this energy, with approximately 6 percent of the energy 
from the explosion transmitted into the water (Yagla and Stiegler 
2003), the amount of energy that would be transmitted into the water 
would be far less than the threshold for Level B harassment for marine 
mammals based on NMFS's current acoustic criterion for in-water 
explosive noise (160 dB re 1 [micro]Pa). As a result, the likelihood of 
in-water sound generated by an explosion of the Falcon 9 First Stage 
during an unsuccessful barge landing attempt resulting in take of 
marine mammals is considered so low as to be discountable and is 
therefore not discussed further in this document.
    As discussed above, in the event of an unsuccessful contingency 
landing attempt, the First Stage would be expected to explode upon 
impact with the barge. SpaceX has experience performing recovery 
operations after water and unsuccessful barge landings for previous 
Falcon 9 First Stage landing attempts. This experience, in addition to 
the debris catalog that identifies all floating debris, has revealed 
that approximately 25 pieces of debris remain floating after an 
unsuccessful barge landing. The approximately 25 pieces of debris would 
primarily be made of Carbon Over Pressure Vessels (COPVs), the liquid 
oxygen fill line, and carbon fiber constructed legs. The vast majority 
of debris would be recovered. All other debris is expected to sink to 
the bottom of the ocean. Denser debris that would not float on the 
surface would sink relatively quickly and is composed of inert 
materials which would not affect water quality or bottom substrate 
potentially used by marine mammals. The rate of deposition would vary 
with the type of debris; however, none of the debris is so dense or 
large that benthic habitat would be meaningfully degraded.
    The surface area potentially impacted with debris would be expected 
to be less than 0.46 km\2\. Since the area impacted by debris is very 
small, the likelihood of adverse effects to marine mammals is very low. 
During previous landing attempts in other locations, SpaceX has 
performed successful debris recovery. All of the recovered debris would 
be transported back to Long Beach Harbor for proper disposal. Most of 
the fuel remaining in the First Stage would be released onto the barge 
deck at the location of impact. Therefore, the likelihood of take of 
marine mammals as a result of contact with exploded First Stage 
materials is considered so low as to be discountable, and explosion of 
the Falcon 9 First Stage is therefore not discussed further in this 
document.
    In the event that a contingency landing action is required, there 
is the potential that the Falcon 9 First Stage would miss the barge 
entirely and land instead in the ocean. However, the likelihood of the 
First Stage missing the barge entirely and landing in the Pacific Ocean 
is considered so unlikely as to be discountable. This is supported by 
several previous attempts by SpaceX at Falcon 9 First Stage barge 
landings, none of which have missed the barge. Therefore, the 
likelihood of take of marine mammals associated with a Falcon 9 First 
Stage landing in the ocean is considered so low as to be discountable, 
and landing of the Falcon 9 First Stage in the ocean is not considered 
further in this document.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    There are six marine mammal species with expected occurrence in the 
project area (including at VAFB, on the NCI, and in the waters 
surrounding VAFB, the NCI and the contingency landing location) that 
are expected to be affected by the specified activities. These include 
the Steller sea lion (Eumetopias jubatus), northern fur seal 
(Callorhinus ursinus), northern elephant seal (Mirounga 
angustirostris), Guadalupe fur seal (Arctocephalus philippii 
townsendi), California sea lion (Zalophus californianus), and Pacific 
harbor seal (Phoca vitulina richardii). This section provides summary 
information regarding local occurrence of these species. We have 
reviewed SpaceX's detailed species descriptions, including life history 
information, for accuracy and completeness and refer the reader to 
Section 3 of SpaceX's IHA application, as well as to NMFS's Stock 
Assessment Reports (SAR; https://www.fisheries.noaa.gov/topic/population-assessments#marine-mammals), rather than reprinting all of 
the information here. Additional general information about these 
species (e.g., physical and behavioral descriptions) may be found on 
NMFS's website (https://www.fisheries.noaa.gov/find-species).
    There are an additional 28 species of cetaceans with expected or 
possible occurrence in the project area. However, we have determined 
that the only potential stressor associated with the activity that 
could result in take of marine mammals (sonic booms) only has the 
potential to result in harassment of marine mammals that are hauled out 
of the water (i.e., pinnipeds). Therefore, we have concluded that the 
likelihood of the proposed activities resulting in the harassment of 
any cetacean to be so low as to be discountable. As we have concluded 
that the likelihood of any cetacean being taken incidentally as a 
result of SpaceX's proposed activities to be so low as to be 
discountable, cetaceans are not considered further in this proposed 
authorization. Please see Table 3-1 in SpaceX's IHA application for a 
complete list of species with expected or potential occurrence in the 
project area.
    Table 1 lists all species with expected potential for occurrence in 
the vicinity of the project during the project timeframe that are 
likely to be affected by the specified activities, and summarizes 
information related to the population or stock, including

[[Page 57436]]

regulatory status under the MMPA and ESA and potential biological 
removal (PBR), where known. For taxonomy, we follow Committee on 
Taxonomy (2017). PBR is 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 (as described in NMFS's SARs). While no 
mortality is anticipated or authorized here, PBR and annual serious 
injury and mortality from anthropogenic sources are included here as 
gross indicators of the status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Pacific and Alaska SARs (e.g., Carretta et al., 2018; Muto 
et al., 2018). All values presented in Table 1 are the most recent 
available at the time of publication and are available in the 2017 SARs 
(Carretta et al., 2018; Muto et al., 2018) and draft 2018 SARs 
(available online at: https://www.fisheries.noaa.gov/topic/population-assessments#marine-mammals).

                                         Table 1--Marine Mammal Species Potentially Present in the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA status;    Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    California sea lion.............  Zalophus californianus.  U.S....................  -; N                257,606 (n/a, 233,515,     14,011      >=197
                                                                                                             2014).
    Northern fur seal...............  Callorhinus ursinus....  California.............  -; N                14,050 (n/a, 7,524,           451      >=0.8
                                                                                                             2013).
    Steller sea lion................  Eumetopias jubatus.....  Eastern U.S............  -; N                41,638 (n/a, 41,638,        2,498        108
                                                                                                             2015).
    Guadalupe fur seal..............  Arctocephalus philippii  Mexico.................  T/D; Y              20,000 (n/a, 15,830,          542      >=3.2
                                                                                                             2010).
Family Phocidae (earless seals):
    Pacific harbor seal.............  Phoca vitulina           California.............  -; N                30,968 (n/a, 27,348,        1,641         30
                                       richardii.                                                            2012).
    Northern elephant seal..........  Mirounga angustirostris  California breeding....  -; N                179,000 (n/a, 81,368,       4,882          4
                                                                                                             2010).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/topic/population-assessments#marine-mammals. CV is coefficient
  of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.

    All species that could potentially occur in the proposed survey 
areas are included in Table 1. As described below, all six species 
(with six managed stocks) temporally and spatially co-occur with the 
activity to the degree that take is reasonably likely to occur, and we 
have proposed authorizing it.

Pacific Harbor Seal

    Harbor seals inhabit coastal and estuarine waters and shoreline 
areas of the northern hemisphere from temperate to polar regions. The 
eastern North Pacific subspecies is found from Baja California north to 
the Aleutian Islands and into the Bering Sea. Multiple lines of 
evidence support the existence of geographic structure among harbor 
seal populations from California to Alaska (Carretta et al., 2016). 
However, because stock boundaries are difficult to meaningfully draw 
from a biological perspective, three separate harbor seal stocks are 
recognized for management purposes along the west coast of the 
continental United States: (1) Washington inland waters (2) Oregon and 
Washington coast, and (3) California (Carretta et al., 2016). In 
addition, harbor seals may occur in Mexican waters, but these animals 
are not considered part of the California stock. Only the California 
stock is considered in this proposed authorization due to the 
distribution of the stock and the geographic scope of the proposed 
activities. Although the need for stock boundaries for management is 
real and is supported by biological information, it should be noted 
that the exact placement of a boundary between California and Oregon 
for stock delineation purposes was largely a political/jurisdictional 
convenience (Carretta et al. 2015).
    Pacific harbor seals are nonmigratory, with local movements 
associated with such factors as tides, weather, season, food 
availability, and reproduction (Scheffer and Slipp 1944, Fisher 1952, 
Bigg 1969, 1981, Hastings et al. 2004). In California, over 500 harbor 
seal haulout sites are widely distributed along the mainland and 
offshore islands, and include rocky shores, beaches and intertidal 
sandbars (Lowry et al. 2005). Harbor seals mate at sea and females give 
birth during the spring and summer, though the pupping season varies 
with latitude. Harbor seal pupping takes place at many locations and 
rookery size varies from a few pups to many hundreds of pups.
    Harbor seals are the most common marine mammal inhabiting VAFB, 
congregating on multiple rocky haulout sites along the VAFB coastline. 
Biologists from the Center for Environmental Management of Military 
Lands (CEMML) and 30 SW, 30th Civil Engineer Squadron (30 CES) survey 
marine mammal haulout sites on VAFB on a monthly basis (CEMML 2018). 
There are 12 harbor seal haulout sites on south VAFB; of these, 10 
sites represent an almost continuous haulout area which is used by the 
same animals.

[[Page 57437]]

Virtually all of the haulout sites at VAFB are used during low tides 
and are wave-washed or submerged during high tides. Additionally, the 
harbor seal is the only species that regularly hauls out near the VAFB 
harbor (CEMML 2018). The main harbor seal haulouts on VAFB are near 
Purisima Point and at Lion's Head (approximately 0.6 km south of Point 
Sal) on north VAFB and between the VAFB harbor north to South Rocky 
Point Beach on south VAFB (ManTech 2009).
    Pups are generally present in the region from March through July. 
Within the affected area on VAFB, a total of up to 332 adults and 34 
pups have been recorded, at all haulouts combined, in monthly counts 
from 2013 to 2015 (ManTech 2015). Harbor seals also haul out, breed, 
and pup in isolated beaches and coves throughout the coasts of San 
Miguel, Santa Rosa, and Santa Cruz Islands (Lowry 2002). During aerial 
surveys conducted by NMFS in May 2002 and May and June of 2004, between 
521 and 1,004 harbors seals were recorded at San Miguel Island, between 
605 and 972 at Santa Rosa Island, and between 599 and 1,102 at Santa 
Cruz Island (M. Lowry, NOAA Fisheries, unpubl. data).
    The harbor seal population at VAFB has undergone an apparent 
decline in recent years (USAF 2013b). This decline has been attributed 
to a series of natural landslides at south VAFB, resulting in the 
abandonment of many haulout sites. These slides have also resulted in 
extensive down-current sediment deposition, making these sites 
accessible to coyotes, which are now regularly seen in the area. Some 
of the displaced seals have moved to other sites at south VAFB, while 
others likely have moved to Point Conception, about 6.5 km south of the 
southern boundary of VAFB. Additionally, at one haulout, harbor seals 
have been displaced by elephant seals, who have begun using the haulout 
for giving birth (CEMML 2018).
    Pacific harbor seals frequently use haulout sites on the NCI, 
including San Miguel, Santa Rosa, Santa Cruz, and Anacapa islands. On 
San Miguel Island, they occur along the north coast at Tyler Bight and 
from Crook Point to Cardwell Point. Additionally, they regularly breed 
on San Miguel Island. On Santa Cruz Island, they inhabit small coves 
and rocky ledges along much of the coast. Harbor seals are scattered 
throughout Santa Rosa Island and also are observed in small numbers on 
Anacapa Island.

California Sea Lion

    California sea lions range from the Gulf of California north to the 
Gulf of Alaska, with breeding areas located in the Gulf of California, 
western Baja California, and southern California. Five genetically 
distinct geographic populations have been identified: (1) Pacific 
Temperate, (2) Pacific Subtropical, (3) Southern Gulf of California, 
(4) Central Gulf of California, and (5) Northern Gulf of California 
(Schramm et al., 2009). Rookeries for the Pacific Temperate population 
are found within U.S. waters and just south of the U.S.-Mexico border, 
and animals belonging to this population may be found from the Gulf of 
Alaska to Mexican waters off Baja California. Animals belonging to 
other populations (e.g., Pacific Subtropical) may range into U.S. 
waters during non-breeding periods. For management purposes, a stock of 
California sea lions comprising those animals at rookeries within the 
United States is defined (i.e., the U.S. stock of California sea lions) 
(Carretta et al., 2017). The carrying capacity of the stock was 
estimated at 275,298 animals in 2014 (Laake et al., 2018).
    Beginning in January 2013, elevated strandings of California sea 
lion pups were observed in southern California, with live sea lion 
strandings nearly three times higher than the historical average. 
Findings to date indicate that a likely contributor to the large number 
of stranded, malnourished pups was a change in the availability of sea 
lion prey for nursing mothers, especially sardines. The Working Group 
on Marine Mammal Unusual Mortality Events determined that the ongoing 
stranding event meets the criteria for an Unusual Mortality Event (UME) 
and declared California sea lion strandings from 2013 through 2017 to 
be one continuous UME. The causes and mechanisms of this event remain 
under investigation. For more information on the UME, see: https://www.fisheries.noaa.gov/national/marine-life-distress/2013-2017-california-sea-lion-unusual-mortality-event-california.
    Rookery sites in southern California are limited to San Miguel 
Island and the southerly Channel Islands of San Nicolas, Santa Barbara, 
and San Clemente (Carretta et al., 2015). Males establish breeding 
territories during May through July on both land and in the water. 
Females come ashore in mid-May and June where they give birth to a 
single pup approximately four to five days after arrival and will nurse 
pups for about a week before going on their first feeding trip. Adult 
and juvenile males will migrate as far north as British Columbia, 
Canada while females and pups remain in southern California waters in 
the non-breeding season. In warm water (El Ni[ntilde]o) years, some 
females are found as far north as Washington and Oregon, presumably 
following prey.
    California sea lions are common offshore of VAFB and haul out on 
rocks and beaches along the coastline of VAFB. At south VAFB, 
California sea lions haul out on north Rocky Point, with numbers often 
peaking in spring. They have been reported at Point Arguello and Point 
Pedernales (both on south VAFB) in the past, although none have been 
noted there over the past several years. Individual sea lions have been 
noted hauled out throughout the VAFB coast; these were transient or 
stranded specimens. They regularly haul out on Lion Rock, north of VAFB 
and immediately south of Point Sal, and occasionally haul out on Point 
Conception, south of VAFB. In 2014, counts of California sea lions at 
haulouts on VAFB ranged from 47 to 416 during monthly counts. Despite 
their prevalence at haulout sites at VAFB, California sea lions rarely 
pup on the VAFB coastline (ManTech 2015); no pups were observed in 2013 
or 2014 (ManTech 2015) and 1 pup was observed in 2015 (VAFB, unpubl. 
data).
    Pupping occurs in large numbers on San Miguel Island at the 
rookeries found at Point Bennett on the west end of the island and at 
Cardwell Point on the east end of the island (Lowry 2002). Sea lions 
haul out at the west end of Santa Rosa Island at Ford Point and 
Carrington Point. A few California sea lions have been born on Santa 
Rosa Island, but no rookery has been established. On Santa Cruz Island, 
California sea lions haul out from Painted Cave almost to Fraser Point, 
on the west end. Fair numbers haul out at Gull Island, off the south 
shore near Punta Arena. Pupping appears to be increasing there. Sea 
lions also haul out near Potato Harbor, on the northeast end of Santa 
Cruz. California sea lions haul out by the hundreds on the south side 
of East Anacapa Island.
    During aerial surveys conducted by NMFS in February 2010 of the 
NCI, 21,192 total California sea lions (14,802 pups) were observed at 
haulouts on San Miguel Island and 8,237 total (5,712 pups) at Santa 
Rosa Island (M. Lowry, NOAA Fisheries, unpubl. data). During aerial 
surveys in July 2012, 65,660 total California sea lions (28,289 pups) 
were recorded at haulouts on San Miguel Island, 1,584 total (3 pups) at 
Santa Rosa Island, and 1,571 total (zero pups) at Santa Cruz Island (M. 
Lowry, NOAA Fisheries, unpubl. data).

Northern Elephant Seal

    Northern elephant seals range in the eastern and central North 
Pacific Ocean,

[[Page 57438]]

from as far north as Alaska and as far south as Mexico. They spend much 
of the year, generally about nine months, in the open ocean. They spend 
much of their lives underwater, diving to depths of about 1,000 to 
2,500 ft (330-800 m) for 20- to 30-minute intervals with only short 
breaks at the surface, and are rarely seen at sea for this reason. 
Northern elephant seals breed and give birth in California and Baja 
California (Mexico), primarily on offshore islands, from December to 
March (Stewart et al. 1994). Adults return to land between March and 
August to molt, with males returning later than females. Adults return 
to their feeding areas again between their spring/summer molting and 
their winter breeding seasons.
    Populations of northern elephant seals in the U.S. and Mexico are 
derived from a few tens or hundreds of individuals surviving in Mexico 
after being nearly hunted to extinction (Stewart et al., 1994). Given 
the recent derivation of most rookeries, no genetic differentiation 
would be expected. Although movement and genetic exchange continues 
between rookeries, most elephant seals return to their natal rookeries 
when they start breeding (Huber et al., 1991). The California breeding 
population is now demographically isolated from the Baja California 
population and is considered to be a separate stock.
    Northern elephant seals haul out sporadically on rocks and beaches 
along the coastline of VAFB; monthly counts in 2013 and 2014 recorded 
between 0 and 191 elephant seals within the affected area (ManTech 
2015) and northern elephant seal pupping at VAFB was documented for the 
first time in January 2017 (Pers. comm., R. Evans, USAF, to J. 
Carduner, NMFS, February 1, 2017). The nearest regularly used haulout 
site on the mainland coast is at Point Conception. Eleven northern 
elephant seals were observed during aerial surveys of the Point 
Conception area by NMFS in February of 2010 (M. Lowry, NOAA Fisheries, 
unpubl. data).
    Point Bennett on the west end of San Miguel Island is the primary 
northern elephant seal rookery in the NCI, with another rookery at 
Cardwell Point on the east end of San Miguel Island (Lowry 2002). They 
also pup and breed on Santa Rosa Island, mostly on the west end. 
Northern elephant seals are rarely seen on Santa Cruz and Anacapa 
Islands. During aerial surveys of the NCI conducted by NMFS in February 
2010, 21,192 total northern elephant seals (14,802 pups) were recorded 
at haulouts on San Miguel Island and 8,237 total (5,712 pups) were 
observed at Santa Rosa Island (M. Lowry, NOAA Fisheries, unpubl. data). 
None were observed at Santa Cruz Island (M. Lowry, NOAA Fisheries, 
unpubl. data).

Steller Sea Lion

    Steller sea lions are distributed mainly around the coasts to the 
outer continental shelf along the North Pacific rim from northern 
Hokkaido, Japan through the Kuril Islands and Okhotsk Sea, Aleutian 
Islands and central Bering Sea, southern coast of Alaska and south to 
California (Loughlin et al., 1984). The species as a whole was ESA-
listed as threatened in 1990 (55 FR 49204, November 26, 1990). In 1997, 
the species was divided into western and eastern distinct population 
segments (DPS), with the western DPS reclassified as endangered under 
the ESA and the eastern DPS retaining its threatened listing (62 FR 
24345, May 5, 2997). On October 23, 2013, NMFS found that the eastern 
DPS has recovered; as a result of the finding, NMFS removed the eastern 
DPS from ESA listing. Only the eastern DPS is considered in this 
proposed authorization due to its distribution and the geographic scope 
of the action.
    Prior to 2012, there were no records of Steller sea lions observed 
at VAFB. In April and May 2012, Steller sea lions were observed hauled 
out at North Rocky Point on VAFB, representing the first time the 
species had been observed on VAFB during launch monitoring and monthly 
surveys conducted over the past two decades (Marine Mammal Consulting 
Group and Science Applications International Corporation 2013). Since 
2012, Steller sea lions have been observed frequently in routine 
monthly surveys, with as many as 16 individuals recorded. In 2014, up 
to five Steller sea lions were observed in the affected area during 
monthly marine mammal counts (ManTech 2015) and a maximum of 12 
individuals were observed during monthly counts in 2015 (VAFB, 
unpublished data). However, up to 16 individuals were observed in 2012 
(SAIC 2012). Steller sea lions once had two small rookeries on San 
Miguel Island, but these were abandoned after the 1982-1983 El 
Ni[ntilde]o event (DeLong and Melin 2000; Lowry 2002); these rookeries 
were once the southernmost colonies of the eastern stock of this 
species. In recent years, between two to four juvenile and adult males 
have been observed on a somewhat regular basis on San Miguel Island 
(pers. comm. Sharon Melin, NMFS Alaska Fisheries Science Center, to J. 
Carduner, NMFS, Feb 11, 2016). Steller sea lions are not observed on 
the other NCI.

Northern Fur Seal

    Northern fur seals occur from southern California north to the 
Bering Sea and west to the Okhotsk Sea and Honshu Island, Japan. Due to 
differing requirements during the annual reproductive season, adult 
males and females typically occur ashore at different, though 
overlapping, times. Adult males occur ashore and defend reproductive 
territories during a three month period from June through August, 
though some may be present until November (well after giving up their 
territories). Adult females are found ashore for as long as six months 
(June-November). After their respective times ashore, fur seals of both 
sexes spend the next seven to eight months at sea (Roppel 1984). Peak 
pupping is in early July and pups are weaned at three to four months. 
Some juveniles are present year-round, but most juveniles and adults 
head for the open ocean and a pelagic existence until the next year. 
Northern fur seals exhibit high site fidelity to their natal rookeries. 
Two stocks of northern fur seals are recognized in U.S. waters: An 
eastern Pacific stock and a California stock (formerly referred to as 
the San Miguel Island stock). While animals from the eastern Pacific 
stock are known to travel as far south as Oregon and California (Muto 
et al., 2018), only the California stock is considered in this proposed 
authorization due to its geographic distribution.
    Northern fur seals have rookeries on San Miguel Island at Point 
Bennett and on Castle Rock. Comprehensive count data for northern fur 
seals on San Miguel Island are not available. San Miguel Island is the 
only island in the NCI on which northern fur seals have been observed. 
Although the population at San Miguel Island was established by 
individuals from Alaska and Russian Islands during the late 1960s, most 
individuals currently found on San Miguel are considered resident to 
the island. No haulout or rookery sites exist for northern fur seals on 
the mainland coast. The only individuals that appear on mainland 
beaches are stranded animals.

Guadalupe Fur Seal

    Guadalupe fur seals are found along the west coast of the United 
States. They were abundant prior to seal exploitation, when they were 
likely the most abundant pinniped species on the Channel Islands, but 
are considered uncommon in Southern California. They are typically 
found on shores with abundant large rocks, often at the base of large 
cliffs (Belcher and Lee 2002).

[[Page 57439]]

Increased strandings of Guadalupe fur seals started occurring along the 
entire coast of California in early 2015. This event was declared a 
marine mammal UME. Strandings were eight times higher than the 
historical average, peaking from April through June 2015, and have 
since lessened but continue at a rate that is well above average. Most 
stranded individuals have been weaned pups and juveniles (1-2 years 
old). For more information on this ongoing UME, see: https://www.fisheries.noaa.gov/national/marine-life-distress/2015-2018-guadalupe-fur-seal-unusual-mortality-event-california.
    Comprehensive survey data on Guadalupe fur seals in the NCI is not 
readily available. On San Miguel Island, one to several male Guadalupe 
fur seals had been observed annually between 1969 and 2000 (DeLong and 
Melin 2000) and juvenile animals of both sexes have been seen 
occasionally over the years (Stewart et al. 1987). The first adult 
female at San Miguel Island was seen in 1997. In June 1997, she gave 
birth to a pup in rocky habitat along the south side of the island and, 
over the next year, reared the pup to weaning age. This was apparently 
the first pup born in the Channel Islands in at least 150 years. Since 
2008, individual adult females, subadult males, and between one and 
three pups have been observed annually on San Miguel Island. There are 
estimated to be approximately 20-25 individuals that have fidelity to 
San Miguel, mostly inhabiting the southwest and northwest ends of the 
island. A total of 14 pups have been born on the island since 2009, 
with no more than 3 born in any single season (pers. comm., S. Melin, 
NMFS National Marine Mammal Laboratory, to J. Carduner, NMFS, Aug. 28, 
2015). Thirteen individuals and two pups were observed in 2015 (NMFS 
2016). No haulout or rookery sites exist for Guadalupe fur seals on the 
mainland coast, including VAFB. The only individuals that do appear on 
mainland beaches are stranded animals.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 dB 
threshold from the normalized composite audiograms, with the exception 
for lower limits for low-frequency cetaceans where the lower bound was 
deemed to be biologically implausible and the lower bound from Southall 
et al. (2007) retained. The functional groups and the associated 
frequencies are indicated below (note that these frequency ranges 
correspond to the range for the composite group, with the entire range 
not necessarily reflecting the capabilities of every species within 
that group):
     Pinnipeds in water; Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 hertz (Hz) to 86 
kilohertz (kHz); and
     Pinnipeds in water; Otariidae (eared seals): Generalized 
hearing is estimated to occur between 60 Hz and 39 kHz.
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Six species of marine mammal (four otariid and two phocid) species) 
have the reasonable potential to co-occur with the proposed activities. 
Please refer to Table 1.

   Table 2--Relevant Marine Mammal Functional Hearing Groups and Their
                       Generalized Hearing Ranges
------------------------------------------------------------------------
               Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Phocid pinnipeds (PW) (underwater) (true    50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea    60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The Estimated Take section later in this document 
includes a quantitative analysis of the number of individuals that are 
expected to be taken by this activity. The Negligible Impact Analysis 
and Determination section considers the content of this section, the 
Estimated Take section, and the Proposed Mitigation section, to draw 
conclusions regarding the likely impacts of these activities on the 
reproductive success or survivorship of individuals and how those 
impacts on individuals are likely to impact marine mammal species or 
stocks.

Acoustic Effects

    This section contains a brief technical background on sound, the 
characteristics of certain sound types, and on metrics used in this 
proposal inasmuch as the information is relevant to the specified 
activity and to a discussion of the potential effects of the specified 
activity on marine mammals found later in this document.
    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in Hz or cycles per second. Wavelength is the distance 
between two peaks or corresponding points of a sound wave (length of 
one cycle). Higher frequency sounds have shorter wavelengths than lower 
frequency sounds, and typically attenuate (decrease) more rapidly, 
except in certain cases in shallower water. Amplitude is the height of 
the sound pressure wave or the ``loudness''

[[Page 57440]]

of a sound and is typically described using the relative unit of the 
dB. A sound pressure level (SPL) in dB is described as the ratio 
between a measured pressure and a reference pressure and is a 
logarithmic unit that accounts for large variations in amplitude; 
therefore, a relatively small change in dB corresponds to large changes 
in sound pressure. The source level (SL) represents the SPL referenced 
at a distance of 1 m from the source while the received level is the 
SPL at the listener's position. Note that all airborne sound levels in 
this document are referenced to a pressure of 20 [micro]Pa.
    Root mean square is the quadratic mean sound pressure over the 
duration of an impulse. Root mean square is calculated by squaring all 
of the sound amplitudes, averaging the squares, and then taking the 
square root of the average (Urick, 1983). Root mean square accounts for 
both positive and negative values; squaring the pressures makes all 
values positive so that they may be accounted for in the summation of 
pressure levels (Hastings and Popper, 2005). This measurement is often 
used in the context of discussing behavioral effects, in part because 
behavioral effects, which often result from auditory cues, may be 
better expressed through averaged units than by peak pressures.
    Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s) 
represents the total energy contained within a pulse and considers both 
intensity and duration of exposure. Peak sound pressure (also referred 
to as zero-to-peak sound pressure or 0-p) is the maximum instantaneous 
sound pressure measurable in the water at a specified distance from the 
source and is represented in the same units as the rms sound pressure. 
Another common metric is peak-to-peak sound pressure (pk-pk), which is 
the algebraic difference between the peak positive and peak negative 
sound pressures. Peak-to-peak pressure is typically approximately 6 dB 
higher than peak pressure (Southall et al., 2007).
    A-weighting is applied to instrument-measured sound levels in an 
effort to account for the relative loudness perceived by the human ear, 
as the ear is less sensitive to low audio frequencies, and is commonly 
used in measuring airborne noise. The relative sensitivity of pinnipeds 
listening in air to different frequencies is more-or-less similar to 
that of humans (Richardson et al. 1995), so A-weighting may, as a first 
approximation, be relevant to pinnipeds listening to moderate-level 
sounds.
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
human activity) but also on the ability of sound to propagate through 
the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from a given 
activity may be a negligible addition to the local environment or could 
form a distinctive signal that may affect marine mammals. Details of 
source types are described in the following text.
    Sounds are often considered as either pulsed or non-pulsed (defined 
in the following). The distinction between these two sound types is 
important because they have differing potential to cause physical 
effects, particularly with regard to hearing (e.g., Ward, 1997 in 
Southall et al., 2007). Please see Southall et al. (2007) for an in-
depth discussion of these concepts.
    Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic 
booms, impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur 
either as isolated events or repeated in some succession. Pulsed sounds 
are all characterized by a relatively rapid rise from ambient pressure 
to a maximal pressure value followed by a rapid decay period that may 
include a period of diminishing, oscillating maximal and minimal 
pressures, and generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or non-continuous (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems (such as 
those used by the U.S. Navy). The duration of such sounds, as received 
at a distance, can be greatly extended in a highly reverberant 
environment.
    The effects of sounds on marine mammals are dependent on several 
factors, including the species, size, behavior (feeding, nursing, 
resting, etc.), and, if underwater, depth of the animal; the intensity 
and duration of the sound; and the sound propagation properties of the 
environment. Impacts to marine species can result from physiological 
and behavioral responses to both the type and strength of the acoustic 
signature (Viada et al., 2008). The type and severity of behavioral 
impacts are more difficult to define due to limited studies addressing 
the behavioral effects of sounds on marine mammals. Potential effects 
from impulsive sound sources can range in severity from effects such as 
behavioral disturbance or tactile perception to physical discomfort, 
slight injury of the internal organs and the auditory system, or 
mortality (Yelverton et al., 1973).
    The effects of sounds from the proposed activities are expected to 
result in behavioral disturbance of marine mammals. Due to the expected 
sound levels of the activities proposed and the distance of the 
activity from marine mammal habitat, the effects of sounds from the 
proposed activities are not expected to result in temporary or 
permanent hearing impairment (TTS and PTS, respectively), non-auditory 
physical or physiological effects, or masking in marine mammals. 
Therefore, TTS, PTS, non-auditory physical or physiological effects, 
and masking are not discussed further in this section.

Disturbance Reactions

    Disturbance includes a variety of effects, including subtle changes 
in behavior, more conspicuous changes in activities, and displacement. 
Behavioral responses to sound are highly variable and context-specific 
and reactions, if any, depend on species, state of maturity, 
experience, current activity, reproductive state, auditory sensitivity, 
time of day, and many other factors (Richardson et al., 1995; Wartzok 
et al., 2003; Southall et al., 2007).
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. Behavioral state may affect

[[Page 57441]]

the type of response as well. For example, animals that are resting may 
show greater behavioral change in response to disturbing sound levels 
than animals that are highly motivated to remain in an area for feeding 
(Richardson et al., 1995; NRC, 2003; Wartzok et al., 2003).
    Controlled experiments with captive marine mammals have shown 
pronounced behavioral reactions, including avoidance of loud underwater 
sound sources (Ridgway et al., 1997; Finneran et al., 2003). Observed 
responses of wild marine mammals to loud pulsed sound sources 
(typically seismic guns or acoustic harassment devices) have been 
varied but often consist of avoidance behavior or other behavioral 
changes suggesting discomfort (Morton and Symonds, 2002; Thorson and 
Reyff, 2006; see also Gordon et al., 2004; Wartzok et al., 2003; 
Nowacek et al., 2007).
    The onset of noise can result in temporary, short term changes in 
an animal's typical behavior and/or avoidance of the affected area. 
These behavioral changes may include: Reduced/increased vocal 
activities; changing/cessation of certain behavioral activities (such 
as socializing or feeding); visible startle response or aggressive 
behavior; avoidance of areas where sound sources are located; and/or 
flight responses (Richardson et al., 1995).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could potentially be biologically significant if the 
change affects growth, survival, or reproduction. The onset of 
behavioral disturbance from anthropogenic sound depends on both 
external factors (characteristics of sound sources and their paths) and 
the specific characteristics of the receiving animals (hearing, 
motivation, experience, demography) and is difficult to predict 
(Southall et al., 2007).
    Marine mammals that occur in the project area could be exposed to 
airborne sounds associated with Falcon 9 boost-back and landing 
activities that have the potential to result in behavioral harassment, 
depending on an animal's distance from the sound. Airborne sound could 
potentially affect pinnipeds that are hauled out. Most likely, airborne 
sound would cause behavioral responses similar to those discussed above 
in relation to underwater sound. For instance, anthropogenic sound 
could cause hauled out pinnipeds to exhibit changes in their normal 
behavior, such as reduction in vocalizations, or cause them to 
temporarily abandon their habitat and move further from the source. 
Hauled out pinnipeds may flush from a haulout into the water. Though 
pup abandonment could theoretically result from these reactions, site-
specific monitoring data indicate that pup abandonment is not likely to 
occur as a result of the specified activity. Not all pinnipeds exposed 
to a sonic boom and/or launch noise flushed from the haulout, and those 
that did flush returned to the haulout shortly after the event.

Description of Effects From the Specified Activity

    This section includes a discussion of the active acoustic sound 
sources associated with SpaceX's proposed activity and the likelihood 
for these sources to result in harassment of marine mammals. Potential 
acoustic sources associated with SpaceX's proposed activity include 
sonic booms, Falcon 9 First Stage landings, and potential explosions as 
a result of unsuccessful Falcon 9 First Stage landing attempts. Sounds 
produced by the proposed activities may be impulsive, due to sonic 
booms, and non-pulse (but short-duration) noise, due to combustion 
effects of the Falcon 9 First Stage. As described above, sounds 
associated with Falcon 9 First Stage landings and potential explosions 
as a result of unsuccessful Falcon 9 First Stage landing attempts are 
not expected to result in take of marine mammals and are therefore not 
addressed here.

Sonic Boom

    As described above, during descent when the First Stage is 
supersonic, a sonic boom would be generated. The USAF has monitored 
pinniped responses to rocket launches from VAFB for nearly 20 years. 
Though rocket launches are not part of the proposed activities (as 
described above), the acoustic stimuli (sonic booms) associated with 
launches is expected to be substantially similar to those expected to 
occur with Falcon 9 boost-backs and landings; therefore, we rely on 
observational data on responses of pinnipeds to sonic booms associated 
with rocket launches from VAFB in making assumptions about expected 
pinniped responses to sonic booms associated with Falcon 9 boost-backs 
and landings.
    Observed reactions of pinnipeds at the NCI to sonic booms have 
ranged from no response to heads-up alerts, from startle responses to 
some movements on land, and from some movements into the water to very 
occasional stampedes (especially involving California sea lions on the 
NCI). We therefore assume sonic booms generated during the return 
flight of the Falcon 9 First Stage may elicit an alerting or other 
short-term behavioral reaction, including flushing into the water if 
hauled out.
    Data from launch monitoring by the USAF on the NCI has shown that 
pinniped reactions to sonic booms are correlated with the level of the 
sonic boom. Low energy sonic booms (<1.0 psf) have typically resulted 
in little to no behavioral responses, including head raising and 
briefly alerting but returning to normal behavior shortly after the 
stimulus (Table 3). More powerful sonic booms have sometimes resulted 
in some species of pinnipeds flushing from haulouts. No documented 
pinniped mortalities have been associated with sonic booms. No 
sustained decreases in numbers of animals observed at haulouts have 
been observed after the stimulus. Table 3 presents a summary of 
monitoring efforts at the NCI from 1999 to 2017. These data show that 
reactions to sonic booms tend to be insignificant below 1.0 psf and 
that, even above 1.0 psf, only a portion of the animals present have 
reacted to the sonic boom. Time-lapse video photography during four 
launch events revealed that harbor seals that reacted to the rocket 
launch noise but did not leave the haulout were all adults.
    Data from previous monitoring also suggests that for those 
pinnipeds that flush from haulouts in response to sonic booms, the 
amount of time it takes for those animals to begin returning to the 
haulout site, and for numbers of animals to return to pre-launch 
levels, is correlated with sonic boom sound levels. Pinnipeds may begin 
to return to the haulout site within 2-55 min of the launch 
disturbance, and the haulout site usually returned to pre-launch levels 
within 45-120 min. Monitoring data from launches of the Athena IKONOS 
rocket from VAFB, with 107.3 and 107.8 dB (A-weighted SEL) recorded at 
the closest haulout site, showed seals that flushed to the water on 
exposure to the sonic boom began to return to the haulout approximately 
16-55 minutes post-launch (Thorson et al., 1999a; 1999b). In contrast, 
in the cases of Atlas rocket launches and several Titan II rocket 
launches with SELs (A-weighted) ranging from 86.7 to 95.7 dB recorded 
at the closest haulout, seals began to return to the haulout site 
within 2-8 minutes post-launch (Thorson and Francine, 1997; Thorson et 
al., 2000).
    Monitoring data has consistently shown that reactions among 
pinnipeds

[[Page 57442]]

to sonic booms vary between species, with harbor seals tending to be 
the most sensitive to disturbance, followed by California sea lions, 
with northern elephant seals and northern fur seals generally being 
much less responsive (Table 3). Because Steller sea lions and Guadalupe 
fur seals occur in the project area relatively infrequently, no data 
has been recorded on their reactions to sonic booms. At VAFB, harbor 
seals generally alert to nearby launch noises, with some or all of the 
animals going into the water. Usually the animals haul out again from 
within minutes to two hours or so of the launch, provided rising tides 
or breakers have not submerged the haulout sites. Post-launch surveys 
often indicate as many or more animals hauled out than were present at 
the time of the launch, unless rising tides, breakers or other 
disturbances are involved (SAIC 2012). When launches occurred during 
high tides at VAFB, no impacts have been recorded because virtually all 
haulout sites were submerged.
    At the Channel Islands, harbor seals have been observed to react 
more strongly to sonic booms than other species present there, with 
some animals startling and fleeing into the water (Table 3). California 
sea lions have also sometimes shown reactiveness to sonic booms, with 
pups sometimes reacting more than adults, either because they are more 
easily frightened or because their hearing is more acute (Table 3). 
Northern fur seals generally show little or no reaction. Northern 
elephant seals generally exhibit no reaction at all, except perhaps a 
heads-up response or some stirring, especially if sea lions in the same 
area or mingled with the elephant seals react strongly to the boom. 
Post-launch monitoring generally reveals a return to normal patterns 
within minutes up to an hour or two of each launch, regardless of 
species (SAIC 2012).
    Table 3 summarizes monitoring efforts at San Miguel Island during 
which acoustic measurements were successfully recorded and during which 
pinnipeds were observed. Monitoring was conducted at the haulout 
closest to the predicted sonic boom. During more recent launches, night 
vision equipment was used. The table shows only launches during which 
sonic booms were heard and recorded. Many launches from VAFB do not 
result in sonic booms that are detectable at the NCI due to the 
westward trajectory of the rockets. To date, SpaceX has landed only one 
Falcon 9 First Stage at VAFB and the monitoring results are not yet 
available. The table shows that little or no reaction from the four 
species usually occurs when overpressures are below 1.0 psf, and 
sometimes higher. In general, as described above, elephant seals do not 
react unless other animals around them react strongly or if the sonic 
boom is extremely loud, and northern fur seals seem to react similarly.

                    Table 3--Observed Pinniped Responses to Sonic Booms at San Miguel Island
----------------------------------------------------------------------------------------------------------------
                                            Sonic
                                             boom                                     Species and associated
              Launch event                  level        Monitoring location                reactions
                                            (psf)
----------------------------------------------------------------------------------------------------------------
Athena II (April 27, 1999)..............        1.0  Adams Cove................  California sea lion: 866
                                                                                  alerted; 232 (27%) flushed
                                                                                  into water.
                                                                                 Northern elephant seal: Alerted
                                                                                  but did not flush.
                                                                                 Northern fur seal: Alerted but
                                                                                  did not flush.
Athena II (September 24, 1999)..........       0.95  Point Bennett.............  California sea lion: 12 of 600
                                                                                  (2%) flushed into water.
                                                                                 Northern elephant seal: Alerted
                                                                                  but did not flush.
                                                                                 Northern fur seal: Alerted but
                                                                                  did not flush.
Delta II 20 (November 20, 2000).........        0.4  Point Bennett.............  California sea lion: 60 pups
                                                                                  flushed into water; no
                                                                                  reaction from focal group.
                                                                                 Northern elephant seal: No
                                                                                  reaction.
Atlas II (September 8, 2001)............       0.75  Cardwell Point............  California sea lion (Group 1):
                                                                                  No reaction (1,200 animals).
                                                                                 California sea lion (Group 2):
                                                                                  No reaction (247 animals).
                                                                                 Northern elephant seal: No
                                                                                  reaction.
                                                                                 Harbor seal: 2 of 4 flushed
                                                                                  into water.
Delta II (February 11, 2002)............       0.64  Point Bennett.............  California sea lion and
                                                                                  northern fur seal: No reaction
                                                                                  among 485 animals in 3 groups.
                                                                                 Northern elephant seal: No
                                                                                  reaction among 424 animals in
                                                                                  2 groups.
Atlas II (December 2, 2003).............       0.88  Point Bennett.............  California sea lion:
                                                                                  Approximately 40% alerted;
                                                                                  several flushed to water
                                                                                  (number unknown--night
                                                                                  launch).
                                                                                 Northern elephant seal: No
                                                                                  reaction.
Delta II (July 15, 2004)................       1.34  Adams Cove................  California sea lion: 10%
                                                                                  alerted (number unknown--night
                                                                                  launch).
Atlas V (March 13, 2008)................       1.24  Cardwell Point............  Northern elephant seal: No
                                                                                  reaction (109 pups).
Delta II (May 5, 2009)..................       0.76  West of Judith Rock.......  California sea lion: No
                                                                                  reaction (784 animals).
Atlas V (April 14, 2011)................       1.01  Cuyler Harbor.............  Northern elephant seal: No
                                                                                  reaction (445 animals).
Atlas V (September 13, 2012)............       2.10  Cardwell Point............  California sea lion: No
                                                                                  reaction (460 animals).
                                                                                 Northern elephant seal: No
                                                                                  reaction (68 animals).
                                                                                 Harbor seal: 20 of 36 (56%)
                                                                                  flushed into water.
Atlas V (April 3, 2014).................       0.74  Cardwell Point............  Harbor seal: 1 of ~25 flushed
                                                                                  into water; no reaction from
                                                                                  others.
Atlas V (December 12, 2014).............       1.18  Point Bennett.............  Calif. sea lion: 5 of ~225
                                                                                  alerted; none flushed.
Atlas V (October 8, 2015)...............       1.96  East Adams Cove of Point    Calif. sea lion: Pre-launch
                                                      Bennett.                    counts for California sea
                                                                                  lions at the San Miguel Island
                                                                                  monitoring location ranged
                                                                                  from 42 to 166. ~60% of CSL
                                                                                  alerted and raised their
                                                                                  heads. None flushed.
                                                                                 Northern elephant seal: Pre-
                                                                                  launch counts ranged from 107
                                                                                  to 159. No visible response to
                                                                                  sonic boom, none flushed.
                                                                                 Northern fur seal: Pre-launch
                                                                                  counts from 129 to 262. ~60%
                                                                                  of NFS alerted and raised
                                                                                  their heads. None flushed.
Atlas V (March 1, 2017).................   \a\ ~0.8  Cuyler Harbor on San        Northern elephant seal: pre-
                                                      Miguel Island.              launch counts 235-352. 13
                                                                                  alerted; none flushed.
----------------------------------------------------------------------------------------------------------------
\a\ Peak sonic boom at the monitoring site was ~2.2 psf, but was in infrasonic range--not audible to pinnipeds.
  Within the audible frequency spectrum, boom at monitoring site estimated at ~0.8 psf.


[[Page 57443]]

Physiological Responses to Sonic Booms

    To determine if harbor seals experience changes in their hearing 
sensitivity as a result of sounds associated with rocket launches 
(including sonic booms), Auditory Brainstem Response (ABR) testing was 
conducted on 14 harbor seals following four launches of the Titan IV 
rocket, one launch of the Taurus rocket, and two launches of the Delta 
IV rocket from VAFB. ABR tests have not yet been performed following 
Falcon 9 rocket landings nor launches, however results of ABR tests 
that followed launches of other rockets from VAFB are nonetheless 
informative as the sound source (sonic boom) is expected to be the same 
as that associated with the activities proposed by SpaceX.
    Following standard ABR testing protocol, the ABR was measured from 
one ear of each seal using sterile, sub-dermal, stainless steel 
electrodes. A conventional electrode array was used, and low-level 
white noise was presented to the non-tested ear to reduce any 
electrical potentials generated by the non-tested ear. A computer was 
used to produce the click and an eight kHz tone burst stimuli, through 
standard audiometric headphones. Over 1,000 ABR waveforms were 
collected and averaged per trial. Initially the stimuli were presented 
at SPLs loud enough to obtain a clean reliable waveform, and then 
decreased in 10 dB steps until the response was no longer reliably 
observed. Once response was no longer reliably observed, the stimuli 
were then increased in 10 dB steps to the original SPL. By obtaining 
two ABR waveforms at each SPL, it was possible to quantify the 
variability in the measurements.
    Good replicable responses were measured from most of the seals, 
with waveforms following the expected pattern of an increase in latency 
and decrease in amplitude of the peaks, as the stimulus level was 
lowered. Detailed analysis of the changes in waveform latency and 
waveform replication of the ABR measurements for the 14 seals showed no 
detectable changes in the seals' hearing sensitivity as a result of 
exposure to the launch noise. The delayed start (1.75 to 3.5 hours 
after the launches) for ABR testing allows for the possibility that the 
seals may have recovered from a TTS before testing began. However, it 
can be said with confidence that the post-launch tested animals did not 
have permanent hearing changes due to exposure to the launch noise from 
the sonic booms associated with launches of the rockets from VAFB (SAIC 
2013).
    We also note that stress from long-term cumulative sound exposures 
can result in physiological effects on reproduction, metabolism, and 
general health, or on the animals' resistance to disease. However, this 
is not likely to occur as a result of the proposed activities because 
of the infrequent nature and short duration of the noise (up to twelve 
sonic booms annually). Research indicates that population levels at 
these haulout sites have remained constant in recent years (with 
decreases only noted in some areas after coastal erosion), giving 
support to this conclusion.
    In conclusion, based on data from numerous years of monitoring of 
similar activities to the activities proposed by SpaceX, in the same 
geographic area as the geographic area of the SpaceX's proposed 
activities, we expect that any behavioral responses by pinnipeds to 
sonic booms resulting from the proposed activities would range from no 
response to heads-up alerts, startle responses, some movements on land, 
and some movements into the water (flushing).

Non-Acoustic Effects of the Proposed Activity

    This section includes a discussion of potential effects of SpaceX's 
proposed activity other than those related to sound.

Visual Stimuli

    Visual stimuli resulting from Falcon 9 First Stage landings would 
have the potential to cause pinnipeds to lift their heads, move towards 
the water, or enter the water. However, SpaceX has determined that the 
trajectory of the return flight includes a nearly vertical descent to 
the SLC-4W landing pad (see Figure 1-7 and 1-8 in the IHA application) 
and the contingency landing location (see Figure 1-5 in the IHA 
application). As a result, the descending Falcon 9 First Stage would 
either be shielded by coastal bluffs (for a SLC-4W landing) or would be 
too far away from any pinniped haulouts to result in significant 
stimuli (in the case of a barge landing). Further, the visual stimulus 
of the Falcon 9 First Stage would not be coupled with the sonic boom, 
since the First Stage would be at significant altitude when the 
overpressure is produced, further decreasing the likelihood of a 
behavioral response. Therefore, the likelihood of takes of marine 
mammals resulting from visual stimuli associated with the proposed 
activity is so low as to be considered discountable. As such, visual 
stimuli associated with the proposed activity is not discussed further 
in this document.

Effects on Marine Mammal Habitat

    We do not anticipate that the proposed activities would result in 
any temporary or permanent effects on the habitats used by the marine 
mammals in the proposed area, including the food sources they use 
(i.e., fish and invertebrates). Behavioral disturbance caused by in-air 
acoustic stimuli may result in marine mammals temporarily moving away 
from or avoiding the exposure area but are not expected to have long 
term impacts, as supported by over two decades of launch monitoring 
studies on the NCI by the USAF (MMCG and SAIC 2012).
    The proposed activities would not result in in-water acoustic 
stimuli that would cause significant injury or mortality to prey 
species and would not create barriers to movement for marine mammal 
prey. As described above, in the event of an unsuccessful barge landing 
and a resulting explosion of the Falcon 9 First Stage, up to 25 pieces 
of debris would likely remain floating. SpaceX would recover all 
floating debris. Denser debris that would not float on the surface is 
anticipated to sink relatively quickly and would be composed of inert 
materials. The area of benthic habitat impacted by falling debris would 
be very small (approximately 0.000706 km\2\) (ManTech 2015) and all 
debris that would sink are composed of inert materials that would not 
affect water quality or bottom substrate potentially used by marine 
mammals. None of the debris would be so dense or large that benthic 
habitat would be meaningfully degraded. As a result, debris from an 
unsuccessful barge landing that enters the ocean environment 
approximately 50 km offshore of VAFB would not have a significant 
effect on marine mammal habitat.
    In summary, since the acoustic impacts associated with the proposed 
activities are of short duration and infrequent (up to twelve events 
annually), the associated behavioral responses in marine mammals are 
expected to be temporary. Therefore, the proposed activities are 
unlikely to result in long term or permanent avoidance of the exposure 
areas or loss of habitat. The proposed activities are also not expected 
to result in any reduction in foraging habitat or adverse impacts to 
marine mammal prey. Thus, any impacts to marine mammal habitat are not 
expected to cause significant or long-term consequences for individual 
marine mammals or their populations.

[[Page 57444]]

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of ``small numbers'' 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 would be by Level B harassment only, in the form 
of potential disruption of behavioral patterns for individual marine 
mammals resulting from exposure to sounds associated with the planned 
activities. Based on the nature of the activity, Level A harassment is 
neither anticipated nor proposed to be authorized.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Generally speaking, 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. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe the 
factors considered here in more detail and present the proposed take 
estimate.

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). Thresholds have also 
been developed identifying the received level of in-air sound above 
which exposed pinnipeds would likely be behaviorally harassed.
    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., 2012). Based on what the available science indicates 
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. As described above, for in-air sounds, 
NMFS predicts that harbor seals exposed above received levels of 90 dB 
re 20 [mu]Pa (rms) will be behaviorally harassed, and other pinnipeds 
will be harassed when exposed above 100 dB re 20 [mu]Pa (rms).
    Typically, NMFS relies on the acoustic criteria described above to 
estimate take as a result of exposure to airborne sound from a given 
activity. However, in this case we have the benefit of more than 20 
years of observational data on pinniped responses to the stimuli 
associated with the proposed activity that we expect to result in 
harassment (sonic booms) in the particular geographic area of the 
proposed activity (VAFB and the NCI). Therefore, we consider these data 
to be the best available information in regard to estimating take based 
on modeled exposures among pinnipeds to sounds associated with the 
proposed activities. These data suggest that pinniped reactions to 
sonic booms are dependent on the species and the intensity of the sonic 
boom (Table 3).
    As described above, data from launch monitoring by the USAF on the 
NCI and at VAFB have shown that pinniped reactions to sonic booms are 
correlated to the level of the sonic boom. Low energy sonic booms (<1.0 
psf) have typically resulted in little to no behavioral responses, 
including head raising and briefly alerting but returning to normal 
behavior shortly after the stimulus. More powerful sonic booms have 
sometimes resulted in animals flushing from haulouts (but not resulted 
in any mortality or sustained decreased in numbers after the stimulus). 
Table 3 presents a summary of monitoring efforts at the NCI from 1999 
to 2017. These data show that reactions to sonic booms tend to be 
insignificant below 1.0 psf and that, even above 1.0 psf, only a 
portion of the animals present react to the sonic boom. Therefore, for 
the purposes of estimating the extent of take that is likely to occur 
as a result of the proposed activities, we conservatively assume that 
Level B harassment may occur when a pinniped (on land) is exposed to a 
sonic boom at or above 1.0 psf. Thus, the number of expected takes by 
Level B harassment is based on estimates of the numbers of animals that 
would be within the areas exposed to sonic booms at levels at or above 
1.0 psf.
    The data recorded by USAF at VAFB and the NCI over the past 20 
years has also shown that pinniped reactions to sonic booms vary 
between species. As described above, little or no reaction has been 
observed in northern fur seals and northern elephant seals when 
overpressures were below 1.0 psf. At the NCI harbor seals have reacted 
more strongly to sonic booms than most other species. Sea lions also 
appear to be somewhat more sensitive to sonic booms than some of the 
other pinniped species, sometimes startling and flushing. Northern fur 
seals generally show little or no reaction, and northern elephant seals 
generally exhibit no reaction at all, except perhaps a heads-up 
response or some stirring, especially if sea lions in the same area 
mingled with the elephant seals react strongly to the boom. No data is 
available on Steller sea lion or Guadalupe fur seal responses to sonic 
booms.

Ensonified Area

    As described above, modeling was performed to estimate overpressure 
levels that would be created during the return flight of the Falcon 9 
First Stage. Previous acoustic modeling underestimated the near-field 
overpressures from sonic booms so SpaceX used actual observations from 
past Falcon 9 First Stage boost-back and landing events. SpaceX and the 
USAF developed new estimates to better predict the potential 
overpressures from sonic booms resulting from Falcon 9 First Stage 
boost-back and landing events. The highest modeled overpressure on the 
mainland (at or near VAFB and Point Conception) was between 1 and 8.5 
psf at SLC-4W. However, the overpressure at known pinniped haulout 
sites on VAFB would likely be closer to 1 to 3 psf (Figure 6-1 in the 
IHA application). SpaceX used the Wyle model to predict the far-field 
sonic boom contours from sonic booms

[[Page 57445]]

produced by boost-back and landing events of Falcon 9 First Stage 
rockets with light and heavy payloads (Figures 2-4 and 2-5 in the IHA 
application). With a heavy payload, Wyle predicted that a boost-back 
and landing of the Falcon 9 First Stage at SLC-4W would produce a sonic 
boom with overpressures up to 3.1 psf on the northern coast of San 
Miguel Island (Figure 2-5 in the IHA application). The Wyle model for a 
heavy payload (Figure 205 in the IHA application) shows a sonic boom 
with overpressure above 1.0 psf will only impact San Miguel Island, 
with no sonic booms over 1.0 psf impacting the other NCI. Therefore, 
takes are estimated based on only the animals hauled out at San Miguel 
Island and the mainland (VAFB and Point Conception).
    As stated in the ``Description of Proposed Activity'' section 
above, no takes are anticipated for landings of Falcon 9 First Stage 
rockets at either of the two contingency landing sites. Estimated takes 
are therefore based on the possibility of boost-back and landing 
activities occurring at SLC-4W.

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. Data collected from marine mammal surveys, including 
monthly marine mammal surveys conducted by the USAF at VAFB (beginning 
in 1993) as well as data collected by NMFS, represent the best 
available information on the occurrence of the six pinniped species 
expected to occur in the project area. The quality and amount of 
information available on pinnipeds in the project area varies depending 
on species. California sea lions, Steller sea lions, harbor seals, and 
northern elephant seals are regularly observed at known haulouts during 
monthly surveys at VAFB (CEMML 2018). Data on pinniped numbers at the 
NCI is limited as surveys are not conducted as frequently. However, the 
best available data was used to estimate take numbers. Take estimates 
for all species are shown in Table 7.
    Harbor Seal--Pacific harbor seals are the most common marine mammal 
inhabiting VAFB, congregating on several rocky haulout sites along the 
VAFB coastline. They also haul out, breed, and pup in isolated beaches 
and coves throughout the coasts of the NCI. Harbor seals may be exposed 
to sonic booms above 1.0 psf on the mainland and San Miguel Island. 
Take of harbor seals at VAFB was estimated based on the maximum count 
totals from monthly surveys of VAFB haulout sites in 2017 (USAF, 2017). 
Take of harbor seals at San Miguel Island and at Point Conception was 
estimated based on the maximum count totals from aerial survey data 
collected from 2002 to 2012 by the NMFS SWFSC (M. Lowry, NMFS SWFSC, 
unpubl. data).
    California sea lion--California sea lions are common offshore of 
VAFB and haul out on rocks and beaches along the coastline of VAFB, 
though pupping rarely occurs on the VAFB coastline. They haul out in 
large numbers on the NCI and rookeries exist on San Miguel and Santa 
Cruz islands. California sea lions may be exposed to sonic booms above 
1.0 psf on the mainland and San Miguel Island. Take of California sea 
lions at VAFB was estimated based on the maximum count totals from 
monthly surveys of VAFB haulout sites in 2017 (USAF, 2017). Take of 
California sea lions at San Miguel Island was estimated based on the 
maximum count totals from aerial survey data collected from 2002 to 
2012 by the NMFS Southwest Fisheries Science Center (SWFSC) (M. Lowry, 
NMFS SWFSC, unpubl. data).
    Steller Sea Lion--Steller sea lions occur in small numbers at VAFB 
and on San Miguel Island. They do not currently have rookeries at VAFB 
or the NCI. Steller sea lions may be exposed to sonic booms above 1.0 
psf on the mainland and San Miguel Island. Take of Steller sea lions at 
VAFB was estimated based on the largest count totals from monthly 
surveys of VAFB haulout sites in 2017 (USAF, 2017). Steller sea lions 
haul out in very small numbers on San Miguel Island, and comprehensive 
survey data for Steller sea lions in the NCI is not available. Take of 
Steller sea lions on San Miguel Island was estimated based on subject 
matter expert input suggesting that as many as four Steller sea lions 
have been observed on San Miguel Island at a time (pers. comm., S. 
Melin, NMFS Marine Mammal Laboratory (MML), to J. Carduner, NMFS, Feb 
11, 2016).
    Northern elephant seal--Northern elephant seals haul out 
sporadically on rocks and beaches along the coastline of VAFB and at 
Point Conception and have rookeries on San Miguel Island and Santa Rosa 
Island and at one location at VAFB. Northern elephant seals may be 
exposed to sonic booms above 1.0 psf on the mainland and San Miguel 
Island. Take of northern elephant seals at VAFB was estimated based on 
the largest count totals from monthly surveys of VAFB haulout sites in 
2017 (USAF, 2017). Take of northern elephant seals on San Miguel Island 
and at Point Conception was estimated based on the maximum count totals 
from aerial survey data collected from 2002 to 2012 by the NMFS 
Southwest Fisheries Science Center (SWFSC) (M. Lowry, NMFS SWFSC, 
unpubl. data).
    Northern fur seal--Northern fur seals have rookeries on San Miguel 
Island, the only island in the NCI on which they have been observed. No 
haulouts or rookeries exist for northern fur seals on the mainland 
coast, including VAFB, thus they may be exposed to sonic booms above 
1.0 psf on San Miguel Island but not on the mainland. Comprehensive 
survey data for northern fur seals in the project area is not 
available. Estimated take of northern fur seals was based on subject 
matter expert input which suggested a maximum of approximately 6,000-
8,000 northern fur seals may be present on San Miguel Island at the 
height of breeding/pupping season (early July). After the height of the 
breeding/pupping season, numbers fluctuate but decrease as females go 
on foraging trips and males begin to migrate in late July/August. 
Numbers continue to decrease until November when most of the population 
is absent from the island until the following breeding/pupping period 
(starting the following June) (pers. comm., T. Orr, NMFS NMML, to J. 
Carduner, NMFS OPR, February 27, 2016). It was therefore conservatively 
estimated that numbers peak at 8,000 animals hauled out at any given 
time in July and decrease to a minimum of 2,000 animals hauled out at 
any given time in the winter, then increase again until the following 
July. This results in an average estimate of 5,000 northern fur seals 
hauled out at San Miguel Island at any given time over the course of 
the entire year.
    Guadalupe fur seal--There are estimated to be approximately 20-25 
individual Guadalupe fur seals that have fidelity to San Miguel Island 
(pers. comm. S. Mellin, NMFS NMML, to J. Carduner, NMFS OPR, February 
11, 2016). No haulouts or rookeries exist for Guadalupe fur seals on 
the mainland coast, including VAFB, thus they may be exposed to sonic 
booms above 1.0 psf at the NCI but not on the mainland. Comprehensive 
survey data on Guadalupe fur seals in the project area is not 
available. Estimated take of Guadalupe fur seals was based on the 
maximum number of Guadalupe fur seals observed at any one time on San 
Miguel Island (13) (pers. comm., J. LaBonte, ManTech SRS Technologies 
Inc., to J. Carduner, NMFS, Feb. 29, 2016); it was therefore 
conservatively assumed that 13 Guadalupe fur seals may be hauled out at 
San Miguel Island at any given time.

[[Page 57446]]

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    NMFS currently uses a three-tiered scale to determine whether the 
response of a pinniped on land to acoustic or visual stimuli is 
considered an alert, a movement, or a flush. NMFS considers the 
behaviors that meet the definitions of both movements and flushes to 
qualify as behavioral harassment. Thus a pinniped on land is considered 
by NMFS to have been behaviorally harassed if it moves greater than two 
times its body length, or if the animal is already moving and changes 
direction and/or speed, or if the animal flushes from land into the 
water. Animals that become alert without such movements are not 
considered harassed. See Table 4 for a summary of the pinniped 
disturbance scale.

                           Table 4--Levels of Pinniped Behavioral Disturbance on Land
----------------------------------------------------------------------------------------------------------------
                                                                                     Characterized as behavioral
         Level                Type of response                  Definition                harassment by NMFS
----------------------------------------------------------------------------------------------------------------
1.....................  Alert.......................  Seal head orientation or       No.
                                                       brief movement in response
                                                       to disturbance, which may
                                                       include turning head towards
                                                       the disturbance, craning
                                                       head and neck while holding
                                                       the body rigid in a u-shaped
                                                       position, changing from a
                                                       lying to a sitting position,
                                                       or brief movement of less
                                                       than twice the animal's body
                                                       length.
2.....................  Movement....................  Movements away from the        Yes.
                                                       source of disturbance,
                                                       ranging from short
                                                       withdrawals at least twice
                                                       the animal's body length to
                                                       longer retreats over the
                                                       beach, or if already moving
                                                       a change of direction of
                                                       greater than 90 degrees.
3.....................  Flush.......................  All retreats (flushes) to the  Yes.
                                                       water.
----------------------------------------------------------------------------------------------------------------

    If issued, this would be the second IHA issued to SpaceX for the 
proposed activity. SpaceX did not perform any Falcon 9 boost-back and 
landing activities that resulted in return flights to VAFB nor that 
generated sonic booms that impacted the NCI. SpaceX did perform boost-
back and landing activities at a contingency landing location located 
offshore during the period of validity for the prior IHA, however the 
contingency landing location was located so far offshore that there 
were no impacts predicted to marine mammals by sonic boom modeling, 
thus marine mammal monitoring was not required. Therefore, we have no 
activity-specific monitoring data to inform take estimates. NMFS relies 
on the past monitoring data presented in Table 3 to estimate takes.
    Take estimates were calculated by overlaying the modeled acoustic 
footprints of sonic booms from boost-back and landing events at SLC-4W 
with known pinniped haulouts on the mainland (including those at VAFB) 
and the NCI to determine the pinniped haulouts that would potentially 
be affected by sonic booms with overpressures of 1.0 psf and above. 
Only haulouts along northeastern San Miguel Island would be expected to 
experience overpressures greater than 1.0 psf during a boost-back and 
landing at SLC-4W (Figure 2-5 in the IHA application). Take estimates 
also account for the likely intensity of the sonic boom as well as the 
relative sensitivity of the marine mammal species present, based on 
monitoring data as described above.
    As described above, the likelihood of pinnipeds exhibiting 
responses to sonic booms that would be considered behavioral harassment 
(based on the levels of pinniped disturbance as shown in Table 4) is 
dependent on both the species and on the intensity of the sonic boom. 
Data from rocket launch monitoring by the USAF at VAFB and the NCI show 
that pinniped reactions to sonic booms are correlated to the level of 
the sonic boom, with low energy sonic booms (<1.0 psf) typically 
resulting in little to no behavioral responses, and higher energy sonic 
booms resulting in responses ranging from no response to heads-up 
alerts, startle responses, some movements on land, and some movements 
into the water (flushing). Based on model results, a boost-back and 
landing of the Falcon 9 First Stage at SLC-4W would produce a sonic 
boom with greater intensity at VAFB (overpressures potentially as high 
as 8.5 psf) than at San Miguel Island (overpressures potentially as 
high as 3.1 psf). Responses of pinnipeds to sonic booms are also highly 
dependent on species, with harbor seals, California sea lions and 
Steller sea lions generally displaying greater sensitivity to sonic 
booms than northern elephant seals and northern fur seals (Table 3). We 
are not aware of any data on Guadalupe fur seal responses to sonic 
booms, but we assume responses by Guadalupe fur seal responses to be 
similar to those observed in northern fur seals as the two species are 
physiologically and behaviorally very similar.
    In their application, SpaceX assumed that all of the California sea 
lions, harbor seals, northern elephant seals, Steller sea lions, 
northern fur seals, and Guadalupe fur seals at or near VAFB and Point 
Conception would be behaviorally harassed by a sonic boom over 1.0 psf 
resulting from a Falcon 9 First Stage boost-back and landing at SLC-4W. 
SpaceX also estimated that 5 percent of northern elephant seals, 
northern fur seals, and Guadalupe fur seals and 100 percent of 
California sea lions, harbor seals, and Steller sea lions hauled out in 
the NCI would be behaviorally harassed by a sonic boom over 1.0 psf. 
However, after reviewing the monitoring information presented in Table 
3, NMFS has determined that assuming 100 percent of California sea 
lions, harbor seals, and Steller sea lions would be behaviorally 
harassed is an overestimate. Therefore, NMFS has determined that 
assuming only a fraction of marine mammals exposed to sonic booms over 
1.0 psf will be behaviorally harassed represents a more realistic 
estimate.
    NMFS assumes that the minimum sonic boom overpressure with the 
potential to result in behavioral harassment of pinnipeds is 1.0 psf. 
However, sonic booms with higher overpressures may result in a higher 
proportion of exposed animals reacting to the sound. Modeling indicates 
that the maximum overpressure from a sonic boom resulting from a Falcon 
9 First Stage boost-back and landing at SLC-4W is likely to be greater 
at VAFB and Point Conception than at the NCI (Figures 2-2, 2-4, and 2-5 
in the IHA application). Thus, based on previous monitoring data (Table 
3), the proportion of animals responding to the sonic boom is likely to 
be greater at VAFB and Point Conception than at the NCI. Therefore, a 
boost-back and landing of the Falcon 9 First Stage at SLC-4W that 
results in a sonic boom of

[[Page 57447]]

1.0 psf and above at VAFB was conservatively estimated to result in 
behavioral harassment of 75 percent of harbor seals hauled out at or 
near VAFB and Point Conception. A sonic boom of 1.0 psf and above at 
the NCI was conservatively estimated to result in behavioral harassment 
of 50 percent of harbor seals at San Miguel Island. A sonic boom of 1.0 
psf and above at VAFB was conservatively estimated to result in 
behavioral harassment of 15 percent of northern elephant seals hauled 
out at or near VAFB and Point Conception while a sonic boom of 1.0 psf 
and above at the NCI was conservatively estimated to result in 
behavioral harassment of 5 percent of northern elephant seals hauled 
out at San Miguel Island. A sonic boom of 1.0 psf and above at VAFB was 
conservatively estimated to result in behavioral harassment of 50 
percent of California sea lions and Steller sea lions hauled out at or 
near VAFB while a sonic boom of 1.0 psf and above at the NCI was 
conservatively estimated to result in behavioral harassment of 25 
percent of California and Steller sea lions hauled out at San Miguel 
Island. A sonic boom of 1.0 psf and above at the NCI was conservatively 
estimated to result in behavioral harassment of 5 percent of northern 
fur seals and Guadalupe fur seals.
    In their application, SpaceX conservatively assumed 12 landings 
would occur at SLC-4W. SpaceX modeled sonic booms resulting from 
rockets with both heavy and light payloads. Modeling of sonic boom 
contours indicates that light payloads do not create sonic booms with 
overpressures above 1.0 psf that would impact the NCI. Only heavy 
payloads have the potential to create sonic booms with overpressures 
above 1.0 psf along the northern coast of San Miguel Island. SpaceX 
indicated that of the up to 12 Falcon 9 First Stage boost-back and 
landing events, up to six would be from a light payload and up to six 
would be from a heavy payload (pers. comm., M. Thompson, SpaceX, to A. 
Fowler, NMFS, Oct. 11, 2018). Therefore, to determine the estimated 
number of marine mammals that could be exposed to a sonic boom over 1.0 
psf, the number of boost-back and landing events that could impact each 
location (12 for the mainland and 6 for the NCI) was multiplied by the 
number of animals likely to respond.
    The take calculations presented in Table 5 are based on the best 
available information on marine mammal populations in the project 
location and responses among marine mammals to the stimuli associated 
with the proposed activities and are considered conservative.

   Table 5--Estimated Numbers of Marine Mammals, and Percentage of Marine Mammal Populations, Potentially Taken as a Result of the Proposed Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Takes per
                                                                Number at    Correction  event after   Number of   Total takes                Percent of
               Species                        Location           location      factor     correction   events at       per      Total takes     stock
                                                                                            factor      location     location
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pacific Harbor Seal.................  VAFB \a\...............          197         0.75       147.75           12        1,773        7,347     \e\ 3.30
                                      Pt. Conception \b\.....          516         0.75          387           12        4,644  ...........  ...........
                                      San Miguel Island \b\..          310          0.5          155            6          930  ...........  ...........
California Sea Lion.................  VAFB \a\...............           68          0.5           34           12          408        3,609         1.40
                                      Pt. Conception \b\.....            0          N/A            0          N/A            0  ...........  ...........
                                      San Miguel Island \b\..        2,134         0.25        533.5            6        3,201  ...........  ...........
Northern Elephant Seal..............  VAFB \a\...............          225         0.15        33.75           12          405        430.2         0.24
                                      Pt. Conception \b\.....           11         0.15         1.65           12         19.8  ...........  ...........
                                      San Miguel Island \b\..           18         0.05          0.9            6          5.4  ...........  ...........
Steller Sea Lion....................  VAFB \a\...............           11          0.5          5.5           12           66           72         0.17
                                      Pt. Conception \b\.....            0          N/A            0          N/A            0  ...........  ...........
                                      San Miguel Island \b\..            4         0.25            1            6            6  ...........  ...........
Northern Fur Seal...................  VAFB \a\...............            0          N/A            0          N/A            0        1,500         10.7
                                      Pt. Conception \b\.....            0          N/A            0          N/A            0  ...........  ...........
                                      San Miguel Island \c\..        5,000         0.05          250            6        1,500  ...........  ...........
Guadalupe Fur Seal..................  VAFB \a\...............            0          N/A            0          N/A            0          3.9         0.02
                                      Pt. Conception \b\.....            0          N/A            0          N/A            0  ...........  ...........
                                      San Miguel Island \d\..           13         0.05         0.65            6          3.9  ...........  ...........
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ VAFB monthly marine mammal survey data 2017 (USAF, 2017).
\b\ Lowry (2017b).
\c\ Testa (2013, 2018); USAF (2013); pers. comm., T. Orr, NMFS NMML, to J. Carduner, NMFS, Feb 27, 2016.
\d\ DeLong and Melin (2000); J. Harris, NOAA Fisheries, pers. comm.
\e\ As the same individual harbor seals at are likely to be taken repeatedly over the course of the specified activities, we use the estimate of 1,023
  individual animals taken per Falcon 9 First Stage recovery activity for the purposes of estimating the percentage of stock abundance likely to be
  taken over the course of the entire activity.

    Take estimates are believed to be conservative based on the 
assumption that all twelve Falcon 9 First Stage recovery actions would 
result in landings at SLC-4W, with no landings occurring at the 
contingency barge landing location. However, some or all actual landing 
events may ultimately occur at the contingency landing location or 
within the Iridium Landing Area; as described above, landings at the 
contingency landing location or within the Iridium Landing Area would 
be expected to result in no takes of marine mammals. However, the 
number of landings at each location is not known in advance, therefore 
we assume all landings would occur at SLC-4W. In addition, as described 
above, it is conservatively assumed that a fraction of marine mammals 
hauled out at VAFB, Point Conception, and San Miguel Island would be 
harassed (Level B harassment only) by a Falcon 9 boost-back and landing 
events at SLC-4W that result in a psf of <1.0. However, it is possible 
that a smaller number of hauled out pinnipeds will be behaviorally 
harassed by a Falcon 9 boost-back and landing at SLC-4W. While there 
may be some limited behavioral harassment of pinnipeds that occurs at 
psf levels <1.0, we account for that in the overall conservativeness of 
the total take number, as described above.
    Given the many uncertainties in predicting the quantity and types 
of impacts of sound on marine mammals, it is common practice to 
estimate how many animals are likely to be present within a particular 
distance of a given activity, or exposed to a particular level of 
sound. In practice, depending on the amount of information available to

[[Page 57448]]

characterize daily and seasonal movement and distribution of affected 
marine mammals, it can be difficult to distinguish between the number 
of individuals harassed and the instances of harassment and, when 
duration of the activity is considered, it can result in a take 
estimate that overestimates the number of individuals harassed. For 
instance, an individual animal may accrue a number of incidences of 
harassment over the duration of a project, as opposed to each incident 
of harassment accruing to a new individual. This is especially likely 
if individual animals display some degree of residency or site fidelity 
and the impetus to use the site is stronger than the deterrence 
presented by the harassing activity.
    Take estimates shown in Table 5 are considered reasonable estimates 
of the number of instances of marine mammal exposures to sound 
resulting in Level B harassment that are likely to occur as a result of 
the proposed activities, and not necessarily the number of individual 
animals exposed.

Proposed 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 
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, as 
well as subsistence uses. 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.

Mitigation for Marine Mammals and Their Habitat

    SpaceX's IHA application contains descriptions of the mitigation 
measures proposed to be implemented during the specified activities in 
order to effect the least practicable adverse impact on the affected 
marine mammal species and stocks and their habitats.
    It should be noted that it would not be feasible to stop or divert 
an inbound Falcon 9 First Stage booster. Once the boost-back and 
landing sequence is underway, there would be no way for SpaceX to 
change the trajectory of the Falcon 9 First Stage to avoid potential 
impacts to marine mammals. The proposed mitigation measures include the 
following:
     Unless constrained by other factors including human safety 
or national security concerns (as determined by the USAF), launches 
would be scheduled to avoid boost-backs and landings during the harbor 
seal pupping season of March through June, when practicable.
    Based on our evaluation of SpaceX's proposed mitigation measures, 
NMFS has preliminarily determined that the proposed 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.

Proposed 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 
proposed 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.

Proposed Monitoring

    SpaceX submitted a monitoring plan as part of their IHA 
application. SpaceX's proposed marine mammal monitoring plan was 
created with input from NMFS and was based on similar plans that have 
been successfully implemented by other action proponents under previous 
authorizations for similar projects, specifically the USAF's monitoring 
of rocket launches from VAFB. The plan may be modified or supplemented 
based on comments or new information received from the public during 
the public comment period.

Marine Mammal Monitoring

    SpaceX would determine a monitoring location for each boost-back 
and landing activity, taking into consideration predictions of the 
areas likely to receive the greatest sonic boom

[[Page 57449]]

intensity as well as current haulout locations and the distribution of 
pinniped species and their behavior. The selection of the monitoring 
location would also be based on what species (if any) have pups at 
haulouts and which of those species would be expected to be the most 
reactive to sonic booms. SpaceX prioritizes the selection of rookery 
locations if they are expected to be impacted by a sonic boom and 
prioritizes the most reactive species if there are multiple species 
that are expected to be hauled out in the modeled sonic boom impact 
area. For instance, if harbor seals were pupping, SpaceX would select a 
harbor seal rookery for monitoring because they tend to be the most 
reactive species to sonic booms. There is also thought given to the 
geography and wind exposure of the specific beaches that are predicted 
to be impacted, to avoid inadvertently selecting a portion of a beach 
that tends to be abandoned by pinnipeds every afternoon as a result 
high winds. As VAFB is an active military base, the selection of 
appropriate monitoring locations must also take into account security 
restrictions and human safety as unexploded ordnance is present in some 
areas.
    Marine mammal monitoring protocols would vary based on modeled 
sonic boom intensity, the location, and the season. As described above, 
sonic boom modeling would be performed prior to all boost-back and 
landing activities. Although the same rockets would be used, other 
parameters specific to each launch would be incorporated into each 
model. These include direction and trajectory, weight, length, engine 
thrust, engine plume drag, position versus time from initiating boost-
back to additional engine burns, among other aspects. Various weather 
scenarios would be analyzed from NOAA weather records for the region, 
then run through the model. Among other factors, these would include 
the presence or absence of the jet stream, and if present, its 
direction, altitude and velocity. The type, altitude, and density of 
clouds would also be considered. From these data, the models would 
predict peak amplitudes and impact locations. As described above, 
impacts to pinnipeds on the NCI, including pups, have been shown 
through more than two decades of monitoring reports to be minimal and 
temporary (MMCG and SAIC 2012a). Therefore monitoring requirements at 
the NCI would be dependent on modeled sonic boom intensity and would be 
based on the harbor seal pupping season, such that monitoring 
requirements would be greater when pups would be expected to be 
present. At the height of the pupping season (between March 1 and June 
30) monitoring is required if sonic boom model results indicate a peak 
overpressure of 2.0 psf or greater is likely to impact the NCI. Between 
July 1 and September 30 monitoring is required if sonic boom model 
results indicate a peak overpressure of 3.0 psf or greater is likely to 
impact the NCI. Between October 1 and February 28, monitoring is 
required if sonic boom model results indicate a peak overpressure of 
4.0 psf or greater is likely to impact the NCI.
    Marine mammal monitoring procedures would consist of the following:
     To conduct monitoring of Falcon 9 First Stage boost-back 
and landing activities, SpaceX would designate qualified, on-site 
observers that would be approved in advance by NMFS;
     If sonic boom model results indicate a peak overpressure 
of 1.0 psf or greater is likely to impact VAFB, then acoustic and 
biological monitoring at VAFB would be implemented. Monitoring would be 
conducted at the haulout site closest to the predicted sonic boom 
impact area that can be safely accessed by observers;
     If sonic boom model results indicate a peak overpressure 
of 2.0 psf or greater is likely to impact one of the NCI between March 
1 and June 30; a peak overpressure of greater than 3.0 psf is likely to 
impact one of the NCI between July 1 and September 30, or a peak 
overpressure of greater than 4.0 psf is likely to impact one of the NCI 
between October 1 and February 28, then monitoring of haulout sites on 
the NCI would be implemented. Monitoring would be conducted at the 
haulout site closest to the predicted sonic boom impact area;
     Monitoring would commence at least 72 hours prior to the 
boost-back and continue until at least 48 hours after the event;
     Monitoring would include multiple surveys each day that 
record the species; number of animals; general behavior; presence of 
pups; age class; gender; and reaction to noise associated with Falcon 9 
First Stage recovery activities, sonic booms or other natural or human 
caused disturbances, in addition to recording environmental conditions 
such as tide, wind speed, air temperature, and swell;
     If the boost-back and landing is scheduled during 
daylight, time lapse photography or video recording would be used to 
document the behavior of marine mammals during Falcon 9 First Stage 
recovery activities;
     For Falcon 9 First Stage recovery activities scheduled 
during harbor seal pupping season (March through June), follow-up 
surveys would be conducted within two weeks of the boost-back and 
landing; and
     New northern elephant seal pupping location(s) at VAFB 
would be prioritized for monitoring when landings occur at SLC-4W 
during northern elephant seal pupping season (January through February) 
when practicable.

Acoustic Monitoring

    Acoustic measurements of the sonic boom created during boost-back 
at the monitoring location would be recorded to determine the 
overpressure level. Typically this would entail use of a digital audio 
tape (DAT) recorder and a high quality microphone to monitor the sound 
environment and measure the sonic boom. This system would be specially 
tailored for recording the low frequency sound associated with rocket 
launches and sonic booms. The DAT system would record the launch noise 
and sonic boom digitally to tape, which would allow for detailed 
post[hyphen]analysis of the frequency content, and the calculation of 
other acoustic metrics, and would record the ambient noise and sonic 
boom. The DAT recorder would be placed near the marine mammal 
monitoring site when practicable.

Proposed Reporting

    SpaceX would report data collected during marine mammal monitoring 
and acoustic monitoring as described above. The monitoring report would 
include a description of project related activities, counts of marine 
mammals by species, sex and age class, a summary of marine mammal 
species/count data, and a summary of observed marine mammal responses 
to project-related activities.
    A launch monitoring report would be submitted by SpaceX to the NMFS 
Office of Protected Resources within 60 days after each Falcon 9 First 
Stage recovery action. This report would contain information on the 
date(s) and time(s) of the Falcon 9 First Stage recovery action, the 
design of the monitoring program; and results of the monitoring 
program, including, but not necessarily limited to the following:
     Numbers of pinnipeds present on the monitored haulout 
prior to the Falcon 9 First Stage recovery;
     Numbers of pinnipeds that may have been harassed (based on 
observations of pinniped responses and the pinniped disturbance scale 
as shown in Table 3);

[[Page 57450]]

     The length of time pinnipeds remained off the haulout or 
rookery for pinnipeds estimated to have entered the water as a result 
of Falcon 9 First Stage recovery noise;
     Any other observed behavioral modifications by pinnipeds 
that were likely the result of Falcon 9 First Stage recovery 
activities, including sonic boom; and
     Results of acoustic monitoring including comparisons of 
modeled sonic booms with actual acoustic recordings of sonic booms.
    In addition, a final monitoring report would be submitted by SpaceX 
to the NMFS Office of Protected Resources. A draft of the report would 
be submitted within 90 days of the expiration of the IHA, or, within 45 
days of the requested renewal of the IHA (if applicable). A final 
version of the report would be submitted within 30 days following 
resolution of comments on the draft report from NMFS. The report would 
summarize the information from the 60-day post-activity reports (as 
described above), including but not necessarily limited to the 
following:
     Date(s) and time(s) of the Falcon 9 First Stage recovery 
actions;
     Design of the monitoring program; and
     Results of the monitoring program, including the 
information components contained in the 60-day launch reports, as well 
as any documented cumulative impacts on marine mammals as a result of 
the activities, such as long term reductions in the number of pinnipeds 
at haulouts as a result of the activities.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner not authorized by the 
proposed IHA (if issued), such as a Level A harassment, or a take of a 
marine mammal species other than those proposed for authorization, 
SpaceX would immediately cease the specified activities and immediately 
report the incident to the NMFS Office of Protected Resources. The 
report would include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Description of the incident;
     Status of all Falcon 9 First Stage recovery activities in 
the 48 hours preceding the incident;
     Description of all marine mammal observations in the 48 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with SpaceX to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. SpaceX would not be able to 
resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that SpaceX discovers an injured or dead marine 
mammal, and the lead observer determines the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition), SpaceX would immediately report the 
incident to the NMFS Office of Protected Resources and the NMFS West 
Coast Region Stranding Coordinator. The report would include the same 
information identified in the paragraph above. Authorized activities 
would be able to continue while NMFS reviews the circumstances of the 
incident. NMFS would work with SpaceX to determine whether 
modifications in the activities are appropriate.
    In the event that SpaceX discovers an injured or dead marine 
mammal, and the lead MMO determines the injury or death is not 
associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), SpaceX would report the incident 
to the NMFS Office of Protected Resources and NMFS West Coast Region 
Stranding Coordinator, within 24 hours of the discovery. SpaceX would 
provide photographs or video footage (if available) or other 
documentation of the stranded animal sighting to NMFS and the Marine 
Mammal Stranding Network.

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's 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, the discussion of our analyses applies to all 
the species listed in Table 1, given that the anticipated effects of 
this activity on these different marine mammal species are expected to 
be similar. Activities associated with the proposed Falcon 9 First 
Stage recovery activities, as outlined previously, have the potential 
to disturb or displace marine mammals. Specifically, the specified 
activities may result in take, in the form of Level B harassment 
(behavioral disturbance) only, from airborne sounds of sonic booms. 
Potential takes could occur if marine mammals are hauled out in areas 
where a sonic boom above 1.0 psf occurs, which is considered likely 
given the modeled sonic booms of the proposed activities and the 
occurrence of pinnipeds in the project area. Based on the best 
available information, including monitoring reports from similar 
activities that have been authorized by NMFS, behavioral responses will 
likely be limited to reactions such as alerting to the noise, with some 
animals possibly moving toward or entering the water, depending on the 
species and the intensity of the sonic boom. Repeated exposures of 
individuals to levels of sound that may cause Level B harassment are 
unlikely to result in hearing impairment or to significantly disrupt 
foraging behavior. Thus, even repeated Level B harassment of some small 
subset of an overall stock is unlikely to result in any significant 
realized decrease in fitness to those individuals, and thus would not 
result in any adverse impact to the stock as a whole. Level B 
harassment would be reduced to the level of least practicable impact 
through use of mitigation measures described above.
    If a marine mammal responds to a stimulus by changing its behavior 
(e.g., through relatively minor changes in locomotion direction/speed), 
the

[[Page 57451]]

response may or may not constitute taking at the individual level, and 
is unlikely to affect the stock or the species as a whole. However, if 
a sound source displaces marine mammals from an important feeding or 
breeding area for a prolonged period, impacts on animals or on the 
stock or species could potentially be significant (e.g., Lusseau and 
Bejder, 2007; Weilgart, 2007). Flushing of pinnipeds into the water has 
the potential to result in mother-pup separation, or could result in a 
stampede, either of which could potentially result in serious injury or 
mortality and thereby could potentially impact the stock or species. 
However, based on the best available information, including reports 
from over 20 years of launch monitoring at VAFB and the NCI, no serious 
injury or mortality of marine mammals is anticipated as a result of the 
proposed activities.
    Even in the instances of pinnipeds being behaviorally disturbed by 
sonic booms from rocket launches at VAFB, no evidence has been 
presented of abnormal behavior, injuries or mortalities, or pup 
abandonment as a result of sonic booms (SAIC 2013). These findings came 
as a result of more than two decades of surveys at VAFB and the NCI 
(MMCG and SAIC, 2012). Post-launch monitoring generally reveals a 
return to normal behavioral patterns within minutes up to an hour or 
two of each launch, regardless of species. For instance, a total of 
eight Delta II and Taurus space vehicle launches occurred from north 
VAFB, near the Spur Road and Purisima Point haulout sites, from 
February, 2009 through February, 2014. Of these eight launches, three 
occurred during the harbor seal pupping season. The continued use by 
harbor seals of the Spur Road and Purisima Point haulout sites 
indicates that it is unlikely that these rocket launches (and 
associated sonic booms) resulted in long-term disturbances of pinnipeds 
using the haulout sites. San Miguel Island represents the most 
important pinniped rookery in the continental United States, and as 
such extensive research has been conducted there for decades. From this 
research, as well as stock assessment reports, it is clear that VAFB 
operations (including associated sonic booms) have not had any 
significant impacts on San Miguel Island rookeries and haulouts (SAIC 
2012).
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
     No injury, serious injury, or mortality are anticipated or 
authorized;
     The anticipated incidences of Level B harassment are 
expected to consist of, at worst, temporary modifications in behavior 
(i.e., short distance movements and occasional flushing into the water 
with return to haulouts shortly after disturbance), which are not 
expected to adversely affect the fitness of any individuals;
     The proposed activities are expected to result in no long-
term changes in the use by pinnipeds of rookeries and haulouts in the 
project area, based on over 20 years of monitoring data; and
     The presumed efficacy of planned mitigation measures in 
reducing the effects of the specified activity to the level of least 
practicable impact.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed 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 Sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and 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.
    The numbers of proposed authorized takes are considered small 
relative to the relevant stocks or populations (less than 11 percent 
for all species and stocks). It is important to note that the number of 
expected takes does not necessarily represent the number of individual 
animals expected to be taken. Our small numbers analysis accounts for 
this fact. Multiple exposures to Level B harassment can accrue to the 
same individual animals over the course of an activity that occurs 
multiple times in the same area (such as SpaceX's proposed activity). 
This is especially likely in the case of species that have limited 
ranges and that have site fidelity to a location within the project 
area, as is the case with Pacific harbor seals.
    As described above, harbor seals are non-migratory, rarely 
traveling more than 50 km from their haulout sites. Thus, while the 
estimated abundance of the California stock of Pacific harbor seals is 
30,968 (Carretta et al. 2017), a substantially smaller number of 
individual harbor seals is likely to occur within the project area. We 
expect that, because of harbor seals' documented site fidelity to 
haulout locations at VAFB and the NCI, and because of their limited 
ranges, the same individuals are likely to be taken repeatedly over the 
course of the proposed activities (maximum of twelve Falcon 9 First 
Stage recovery actions). Therefore, the proposed number of instances of 
Level B harassment among harbor seals over the course of the proposed 
authorization (i.e., the total number of takes shown in Table 5) is 
expected to accrue to a much smaller number of individuals encompassing 
a small portion of the overall regional stock. Thus while we propose to 
authorize the instances of incidental take of harbor seals shown in 
Table 5, we believe that the number of individual harbor seals that 
would be incidentally taken by the proposed activities would, in fact, 
be substantially lower than this number. The maximum number of harbor 
seals expected to be taken by Level B harassment, per Falcon 9 First 
Stage recovery action, is 1,023. As we believe the same individuals are 
likely to be taken repeatedly over the duration of the proposed 
activities, we use the estimate of 1,023 individual animals taken per 
Falcon 9 First Stage recovery activity for the purposes of estimating 
the percentage of the stock abundance likely to be taken.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

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 would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

[[Page 57452]]

Endangered Species Act (ESA)

    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 when we propose to authorize take for 
endangered or threatened species.
    There is one marine mammal species (Guadalupe fur seal) listed 
under the ESA with confirmed occurrence in the area expected to be 
impacted by the proposed activities. The Permits and Conservation 
Division has requested initiation of section 7 consultation with the 
West Coast Region Protected Resources Division Office for the issuance 
of this IHA. NMFS will conclude the ESA consultation prior to reaching 
a determination regarding the proposed issuance of the authorization.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to SpaceX for conducting Falcon 9 First Stage recovery 
activities at Vandenberg Air Force Base, in the Pacific Ocean offshore 
Vandenberg Air Force Base, and at the Northern Channel Islands, 
California, for one year from the date of issuance, provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated. This section contains a draft of the IHA itself. The 
wording contained in this section is proposed for inclusion in the IHA 
(if issued).
    1. This Incidental Harassment Authorization (IHA) is valid for one 
year from the date of issuance.
    (a) This IHA is valid only for Falcon 9 First Stage recovery 
activities at Vandenberg Air Force Base, California, and at auxiliary 
landing sites offshore.
    2. General Conditions
    (a) A copy of this IHA must be in the possession of SpaceX, its 
designees, and work crew personnel operating under the authority of 
this IHA.
    (b) The species authorized for taking are the Pacific harbor seal 
(Phoca vitulina richardii), California sea lion (Zalophus 
californianus), Steller sea lion (Eumetopias jubatus), northern 
elephant seal (Mirounga angustirostris), northern fur seal (Callorhinus 
ursinus), and Guadalupe fur seal (Arctocephalus philippii townsendi).
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 2(b). See Table 5 for numbers of take 
authorized.
    (d) The taking by injury (Level A harassment), serious injury, or 
death of any of the species listed in condition 2(b) of the 
Authorization or any taking of any other species of marine mammal is 
prohibited and may result in the modification, suspension, or 
revocation of this IHA.
    3. Mitigation Measures
    The holder of this Authorization must implement the following 
mitigation measure: Unless constrained by other factors including human 
safety or national security concerns, launches must be scheduled to 
avoid, whenever possible, boost-backs and landings during the harbor 
seal pupping season of March through June.
    4. Monitoring
    The holder of this Authorization must conduct marine mammal and 
acoustic monitoring as described below.
    (a) To conduct monitoring of Falcon 9 First Stage recovery 
activities, SpaceX must designate qualified, on-site individuals 
approved in advance by NMFS;
    (b) If sonic boom model results indicate that a peak overpressure 
of 1.0 psf or greater is likely to impact VAFB, then acoustic and 
biological monitoring at VAFB must be implemented. Monitoring must be 
conducted at the haulout site closest to the predicted sonic boom 
impact area that can be safely accessed by observers;
    (c) If sonic boom model results indicate a peak overpressure of 1.0 
psf or greater is likely to impact VAFB during January and February, 
then acoustic and biological monitoring must be implemented at northern 
elephant seal rookeries at VAFB, when practicable;
    (d) If sonic boom model results indicate that a peak overpressure 
of 2.0 psf or greater is predicted to impact the Channel Islands 
between March 1 and June 30, greater than 3.0 psf between July 1 and 
September 30, and greater than 4.0 psf between October 1 and February 
28, monitoring of haulout sites on the Channel Islands must be 
implemented. Monitoring must be conducted at the haulout site closest 
to the predicted sonic boom impact area that can be safely accessed by 
observers;
    (e) Monitoring must be conducted for at least 72 hours prior to any 
planned Falcon 9 First Stage recovery and continue until at least 48 
hours after the event;
    (f) For Falcon 9 First Stage recovery activities that occur during 
March through June, follow-up surveys of harbor seal haulouts must be 
conducted within two weeks of the Falcon 9 First Stage recovery;
    (g) If Falcon 9 First Stage recovery activities are scheduled 
during daylight, time-lapse photography or video recording must be used 
to document the behavior of marine mammals during Falcon 9 First Stage 
recovery activities;
    (h) Monitoring must include multiple surveys each day that record 
the species, number of animals, general behavior, presence of pups, age 
class, gender and reaction to noise associated with Falcon 9 First 
Stage recovery, sonic booms or other natural or human caused 
disturbances, in addition to recording environmental conditions such as 
tide, wind speed, air temperature, and swell; and
    (i) Acoustic measurements of the sonic boom created during boost-
back at the monitoring location must be recorded to determine the 
overpressure level.
    5. Reporting
    The holder of this Authorization is required to:
    (a) Submit a report to the Office of Protected Resources, NMFS, 
within 60 days after each Falcon 9 First Stage recovery action. This 
report must contain the following information:
    (1) Date(s) and time(s) of the Falcon 9 First Stage recovery 
action;
    (2) Design of the monitoring program; and
    (3) Results of the monitoring program, including, but not 
necessarily limited to:
    (i) Numbers of pinnipeds present on the haulout prior to the Falcon 
9 First Stage recovery;
    (ii) Numbers of pinnipeds that may have been harassed as a result 
of Falcon 9 First Stage recovery activities;
    (iii) For pinnipeds estimated to have been harassed as a result of 
Falcon 9 First Stage recovery noise, the length of time pinnipeds 
remained off the haulout or rookery;
    (iv) Any other observed behavioral modifications by pinnipeds that 
were likely the result of Falcon 9 First Stage recovery activities, 
including sonic boom; and
    (v) Results of acoustic monitoring including comparisons of modeled 
sonic booms with actual acoustic recordings of sonic booms.
    (b) Submit an annual report on all monitoring conducted under the 
IHA. A draft of the annual report must be submitted within 90 calendar 
days of the expiration of this IHA, or, within 45 calendar days of the 
requested renewal of the IHA (if applicable). A final annual report 
must be prepared and submitted within 30 days following resolution of 
comments on the draft report from

[[Page 57453]]

NMFS. The annual report will summarize the information from the 60-day 
post-activity reports, including but not necessarily limited to:
    (1) Date(s) and time(s) of the Falcon 9 First Stage recovery 
action;
    (2) Design of the monitoring program; and
    (3) Results of the monitoring program, including, but not 
necessarily limited to:
    (i) Numbers of pinnipeds present on the haulout prior to the Falcon 
9 First Stage recovery;
    (ii) Numbers of pinnipeds estimated to have been harassed as a 
result of Falcon 9 First Stage recovery activities at the monitoring 
location;
    (iii) For pinnipeds estimated to have been harassed as a result of 
Falcon 9 First Stage recovery noise, the length of time pinnipeds 
remained off the haulout or rookery;
    (iv) Any other observed behavioral modifications by pinnipeds that 
were likely the result of Falcon 9 First Stage recovery activities, 
including sonic boom;
    (v) Any cumulative impacts on marine mammals as a result of the 
activities, such as long term reductions in the number of pinnipeds at 
haulouts as a result of the activities; and
    (vi) Results of acoustic monitoring including comparisons of 
modeled sonic booms with actual acoustic recordings of sonic booms.
    (c) Reporting injured or dead marine mammals:
    (1) In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this IHA 
(as determined by the lead marine mammal observer), such as an injury 
(Level A harassment), serious injury, or mortality, SpaceX must 
immediately cease the specified activities and report the incident to 
the NMFS Office of Protected Resources and the NMFS West Coast Region 
Stranding Coordinator. The report must include the following 
information:
    A. Time and date of the incident;
    B. Description of the incident;
    C. Status of all Falcon 9 First Stage recovery activities in the 48 
hours preceding the incident;
    D. Description of all marine mammal observations in the 48 hours 
preceding the incident;
    E. Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    F. Species identification or description of the animal(s) involved;
    G. Fate of the animal(s); and
    H. Photographs or video footage of the animal(s).
    Activities may not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with SpaceX to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. SpaceX may not 
resume their activities until notified by NMFS via letter, email, or 
telephone.
    (2) In the event that SpaceX discovers an injured or dead marine 
mammal, and the lead observer determines that the cause of the injury 
or death is unknown and the death is relatively recent (e.g., in less 
than a moderate state of decomposition), SpaceX must immediately report 
the incident to the NMFS Office of Protected Resources and the NMFS 
West Coast Region Stranding Coordinator. The report must include the 
same information identified in 5(c)(1) of this IHA. Activities may 
continue while NMFS reviews the circumstances of the incident and makes 
a final determination on the cause of the reported injury or death. 
NMFS will work with SpaceX to determine whether additional mitigation 
measures or modifications to the activities are appropriate.
    (3) In the event that SpaceX discovers an injured or dead marine 
mammal, and the lead observer determines that the injury or death is 
not associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, scavenger damage), SpaceX must report the incident to 
the NMFS Office of Protected Resources and the NMFS West Coast Region 
Stranding Coordinator, within 24 hours of the discovery. SpaceX must 
provide photographs or video footage or other documentation of the 
stranded animal sighting to NMFS. The cause of injury or death may be 
subject to review and a final determination by NMFS.
    6. Modification and suspension
    (a) This IHA may be modified, suspended or withdrawn if the holder 
fails to abide by the conditions prescribed herein, or if NMFS 
determines that the authorized taking is having more than a negligible 
impact on the species or stock of affected marine mammals.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed boost-
back and landings of Falcon 9 First Stage rockets. We also request 
comment on the potential for renewal of this proposed IHA as described 
in the paragraph below. Please include with your comments any 
supporting data or literature citations to help inform our final 
decision on the request for MMPA authorization.
    On a case-by-case basis, NMFS may issue a second one-year IHA 
without additional notice when (1) another year of identical or nearly 
identical activities as described in the Specified Activities section 
is planned or (2) the activities would not be completed by the time the 
IHA expires and a second IHA would allow for completion of the 
activities beyond that described in the Dates and Duration section, 
provided all of the following conditions are met:
     A request for renewal is received no later than 60 days 
prior to expiration of the current IHA.
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted beyond the 
initial dates either are identical to the previously analyzed 
activities or include changes so minor (e.g., reduction in pile size) 
that the changes do not affect the previous analyses, take estimates, 
or mitigation and monitoring requirements; and
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
     Upon review of the request for renewal, the status of the 
affected species or stocks, and any other pertinent information, NMFS 
determines that there are no more than minor changes in the activities, 
the mitigation and monitoring measures remain the same and appropriate, 
and the original findings remain valid.

    Dated: November 9, 2018.
Catherine Marzin,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2018-24977 Filed 11-14-18; 8:45 am]
BILLING CODE 3510-22-P