[Federal Register Volume 88, Number 60 (Wednesday, March 29, 2023)]
[Notices]
[Pages 18572-18576]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-06505]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[Docket No. FWS-R4-ES-2022-0031; FF04E00000-234-FXES11130400000]


Marine Mammal Protection Act; Stock Assessment Reports for Two 
Stocks of West Indian Manatee

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of availability; response to comments.

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SUMMARY: In accordance with the Marine Mammal Protection Act of 1972, 
as amended, we, the U.S. Fish and Wildlife Service, after consideration 
of comments received from the public, have revised the marine mammal 
stock assessment reports (SAR) for two West Indian manatee stocks, the 
Florida manatee stock (Trichechus manatus latirostris) and the Puerto 
Rico stock of the Antillean manatee (Trichechus manatus manatus). We 
now make both final revised SARs available to the public.

ADDRESSES: Document Availability: You may obtain a copy of the stock 
assessment reports for the Florida manatee stock and Puerto Rico stock 
of Antillean manatee by either of the following methods:
     Internet: https://www.regulations.gov. Search for FWS-R4-
ES-2022-0031.
     Write to or call (during normal business hours from 8 a.m. 
to 4:30 p.m., Monday through Friday) the appropriate individual as 
described under FOR FURTHER INFORMATION CONTACT.

FOR FURTHER INFORMATION CONTACT: 
    Florida manatee stock: Lourdes Mena, USFWS Florida Ecological 
Services Field Office, 7915 Baymeadows Way, Suite 200, Jacksonville, 
FL, by telephone (904-731-3134), or by email ([email protected]).
    Puerto Rico manatee stock: Edwin Mu[ntilde]iz, USFWS Caribbean 
Ecological Services Field Office, P.O. Box 491, Boquer[oacute]n, PR, by 
telephone (786-244-0081), or by email ([email protected]).
    Individuals in the United States who are deaf, deafblind, hard of 
hearing, or have a speech disability may dial 711 (TTY, TDD, or 
TeleBraille) to access telecommunications relay services. Individuals 
outside the United States should use the relay services offered within 
their country to make international calls to the point-of-contact in 
the United States.

SUPPLEMENTARY INFORMATION: We announce the availability of the final 
revised stock assessment reports (SARs) for the Florida manatee stock 
(Trichechus manatus latirostris) and the Puerto Rico stock of the 
Antillean manatee (Trichechus manatus manatus).

Background

    Under the Marine Mammal Protection Act of 1972, as amended (MMPA; 
16 U.S.C. 1361 et seq.) and its implementing regulations in the Code of 
Federal Regulations (CFR) at 50 CFR part 18, the U.S. Fish and Wildlife 
Service (Service) regulates the taking; import; and, under certain 
conditions, possession; transportation; purchasing; selling; and 
offering for sale, purchase, or export, of marine mammals. One of the 
goals of the MMPA is to ensure that stocks of marine mammals occurring 
in waters under U.S. jurisdiction do not experience a level of human-
caused mortality and serious injury that is likely to cause the stock 
to be reduced below its optimum sustainable population level (OSP). The 
OSP is defined under the MMPA as the number of animals which will 
result in the maximum productivity of the population or the species, 
keeping in mind the carrying capacity of the habitat and the health of 
the ecosystem of which they form a constituent element (16 U.S.C. 
1362(9)).

[[Page 18573]]

    To help accomplish the goal of maintaining marine mammal stocks at 
their OSPs, section 117 of the MMPA requires the Service and the 
National Marine Fisheries Service (NMFS) to prepare a SAR for each 
marine mammal stock that occurs in waters under U.S. jurisdiction. A 
SAR must be based on the best scientific information available; 
therefore, we prepare it in consultation with an independent Scientific 
Review Group (SRG) established under section 117(d) of the MMPA. Each 
SAR must include:
    1. A description of the stock and its geographic range;
    2. A minimum population estimate, current and maximum net 
productivity rate, and current population trend;
    3. An estimate of the annual human-caused mortality and serious 
injury by source and, for a strategic stock, other factors that may be 
causing a decline or impeding recovery of the stock;
    4. A description of commercial fishery interactions;
    5. A categorization of the status of the stock; and
    6. An estimate of the potential biological removal (PBR) level.
    The MMPA defines the PBR 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 OSP'' (16 
U.S.C. 1362(20)). The PBR is the product of the minimum population 
estimate of the stock (Nmin); one-half the maximum 
theoretical or estimated net productivity rate of the stock at a small 
population size (Rmax); and a recovery factor 
(Fr) of between 0.1 and 1.0, which is intended to compensate 
for uncertainty and unknown estimation errors. This can be written as:

PBR = (Nmin)(\1/2\ of the Rmax)(Fr)

    Section 117 of the MMPA also requires the Service and the NMFS to 
review the SARs (a) at least annually for stocks that are specified as 
strategic stocks, (b) at least annually for stocks for which 
significant new information is available, and (c) at least once every 3 
years for all other stocks. If our review of the status of a stock 
indicates that it has changed or may be more accurately determined, 
then the SAR must be revised accordingly.
    A strategic stock is defined in the MMPA as a marine mammal stock 
for which the level of direct human-caused mortality exceeds the PBR 
level; which, based on the best available scientific information, is 
declining and is likely to be listed as a threatened species under the 
Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.), 
within the foreseeable future; or which is listed as a threatened or 
endangered species under the ESA, or is designated as depleted under 
the MMPA (16 U.S.C. 1362(19)).

Stock Assessment Report History for Two Stocks of West Indian Manatee

    The SARs for the Florida and Puerto Rico stocks of the West Indian 
manatee were last revised in 2014. Because the West Indian manatee is 
listed as a threatened species under the ESA, both stocks are 
considered strategic. Therefore, the Service reviews the stock 
assessment annually. If, based on our annual review, we determine that 
new information (such as new abundance estimates) indicates that a 
revision is warranted, we will propose a revision. In 2020, based on 
new information that had become available, the Service initiated 
revision of the SARs, and once completed, presented them for review to 
the SRG. Subsequent to that review, the Service published a notice in 
the Federal Register informing the public of the availability of these 
draft revised SARs and seeking public comment (87 FR 47445, August 3, 
2022). These final revised SARs incorporate the comments and 
suggestions provided to the Service by the SRG and the public, as 
appropriate.

Summary of Revised Stock Assessment Reports for Two Stocks of West 
Indian Manatee

    The following table summarizes some of the information contained in 
the revised SARs for the Florida and Puerto Rico stocks of the West 
Indian manatee, which includes the stocks' Nmin, 
Rmax, Fr, PBR, annual estimated human-caused 
mortality and serious injury, and status.
    In March 2021, the Service declared an Unusual Mortality Event 
(UME) along the Atlantic coast of Florida for the Florida stock. The 
event, which began in December 2020 and is ongoing, is associated with 
phytoplankton blooms and seagrass loss in the Indian River Lagoon. The 
effect of the UME on population size and trend is not known at this 
time but will be assessed in the future based on new abundance 
estimates that are being developed and additional population modeling. 
We are working closely with our conservation partners to monitor and 
address the UME. No UME has been declared for the Puerto Rico stock.

                         Summary--Revised Stock Assessment Reports for the Florida and Puerto Rico Stocks of West Indian Manatee
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                                                                                           Annual estimated human-caused mortality
      West Indian manatee stock           Nmin         Rmax          Fr          PBR                  (5-year average)                  Stock  status
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Florida manatees....................        8,237        0.062          0.5       127.67  144.8 (Years 2014-2018).................  Strategic
Antillean manatees (Puerto Rico)....          319         0.04          0.4         2.55  4 (Years 2015-2019).....................  Strategic
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Response to Public Comments

    We received comments on the draft SAR for the Florida stock from 
the Florida Fish and Wildlife Conservation Commission (FWC) and the 
Center for Biological Diversity. No comments were submitted on the 
draft SAR for the Puerto Rico stock. We present substantive issues 
raised in those comments that are pertinent to the SAR for the Florida 
stock, edited for brevity, along with our responses below.

Comments Specific to the Stock Assessment Report for the Florida Stock

    Comment 1: The population estimate of 8,810 Florida manatees, 
established from Hostetler et al. (2018), is likely a gross 
overestimate of the number of Florida manatees remaining in the wild 
today. As the SAR recognizes, the ongoing Unusual Mortality Event (UME) 
is not incorporated into this estimate. Though efforts are underway to 
produce an updated abundance estimate, this SAR should, at a minimum, 
incorporate the known deaths from the UME area attributable to 
starvation.
    Response: The draft SAR discussed the basis for the population 
estimate, acknowledged the ongoing UME, and reported the preliminary 
data on the number of deaths that have occurred since the UME began. As 
discussed in the draft SAR, we noted that the effect on the overall 
population size was currently unknown. We have updated

[[Page 18574]]

the final revised SAR to include more recent preliminary data on the 
number of deaths in the UME area and additional discussion about the 
possible population-level effects of the UME. We also clarified the 
reasons why we have not incorporated the UME deaths into the population 
estimate. The final revised SAR maintains that the 2018 population 
estimate, which is a point estimate and a 95 percent confidence 
interval (7,520-10,280), is the best scientific information available. 
It also notes that the UME is primarily affecting one of the four 
management units (the Atlantic Coast unit) and that manatees in the 
other three units are generally exhibiting positive population growth.
    Comment 2: The Service should publish a revised SAR when the 
updated abundance estimate, including total mortality from the ongoing 
UME, is published.
    Response: The draft SAR discussed that the FWC was in the process 
of collecting new aerial survey data to be used to produce an updated 
abundance estimate. We have updated the SAR to note that surveys of the 
East Coast of Florida were flown in December 2022 and that we still 
expect an updated abundance estimate to be available in 2023 or 2024.
    Comment 3: The SAR relies on productivity rates that do not account 
for recent threats to the Florida manatee, including the ongoing UME 
and degradation of seagrass habitat across the State. Not only are the 
adult survival rates significantly impacted by the death of nearly 
2,000 Florida manatees in 2021 and 2022 combined, but starvation 
stressors have likely impacted reproductivity rates as well. The death 
of large numbers of female manatees--at least 415 identified in 2021 
alone--also exacerbates reproductivity concerns by decreasing calving 
rates and orphaning existing calves.
    Response: The survival and reproductive rates reported in the draft 
SAR are the best scientific information available. The draft SAR 
acknowledged the ongoing UME but stated the effects of the UME were 
currently unknown. The final revised SAR retains these same 
conclusions; however, we recognize that the effects of the UME on 
survival and reproductive rates on the population stock as a whole are 
still being assessed, and we anticipate additional information on the 
effects of the UME in the future. Estimates of reproductive rates (and 
survival rates) are most often obtained and tracked using long-term 
longitudinal studies of known identifiable manatees. Therefore, it 
likely will be several years before data are available from the UME 
area that can be used for this purpose. The Florida Fish and Wildlife 
Conservation Commission is working on an Integrated Population Model 
(IPM) for the Atlantic Coast management unit that will provide 
additional insight into the effects of the UME on population size and 
other important metrics, including adult survival and reproductive 
rates. The IPM will use the new abundance estimates that are currently 
being developed, so it will likely be 2024 or later before the IPM 
results will be available. Even if available information indicated 
reduced reproduction in the area of the UME, this information would not 
affect the maximum theoretical net productivity rate, which is what is 
used in the calculation of Potential Biological Removal (PBR).
    Comment 4: The ongoing UME underscores the numerous threats of 
habitat destruction facing the Florida manatee, which should be 
adequately reflected in the SAR. Seagrasses on which manatees depend 
are increasingly being destroyed. Warm water refugia where manatees 
overwinter are threatened. Coastal development also threatens manatee 
habitat.
    Response: The draft SAR discussed all sources of human-caused 
mortality and serious injury, as well as the ongoing UME and all other 
causes of mortality. The Habitat Issues section contains discussions of 
the importance of warm water sites and available forage, and current 
and future threats. The final revised SAR includes updated and 
additional discussion about the ongoing UME, and it meets all of the 
informational requirements of the MMPA section 117.
    Comment 5: While the 2022 SAR for the Florida manatee stock 
provides a cursory overview of these harms, the population estimate of 
8,810 is an unacceptable starting point for recovery discussions. 
Section 117 of the MMPA requires the Service to prepare a SAR to help 
accomplish the goal of maintaining marine mammal stocks at their 
optimum sustainable population levels. SARs must be based on the best 
scientific information available, and there exists ample information to 
incorporate deaths from the ongoing UME. Moreover, the Service should 
immediately revise the SAR when the forthcoming abundance estimate is 
released, as it will provide substantial new information regarding the 
Florida manatee stock. This new information will be critical when 
developing ongoing strategy for manatee conservation, including 
determining potential biological removal levels.
    Response: As mentioned above, this final revised SAR contains the 
best scientific information available and meets the informational 
requirements of the MMPA. To the extent the commenter is referring to 
conservation strategies and other documents for the manatee, which are 
governed by different legal authorities and standards, such as the ESA, 
these comments are beyond the scope of this action. In addition, the 
MMPA requires the annual review of stock assessments for strategic 
stocks, which includes the manatee. During the Service's annual review, 
if we determine that new information (such as new abundance estimates) 
indicate that a revision is warranted, we will propose a revision. This 
final revised SAR includes additional discussion about possible 
population-level effects of the UME.
    Comment 6: While Slone et al. 2017 serves as a recent source of 
information to support the page 2 statement that manatee movements 
outside of Florida appear to be increasing, we recommend citing 
accessible publications such as Pabody et al. 2009 and Hieb et al. 
2017.
    Response: Pabody, et al. 2009 was already included in the draft 
SAR. We have added a citation to Hieb et al. 2017 in this final revised 
SAR.
    Comment 7: Regarding Florida manatee regional management units on 
page 2 (and illustrated on page 3), the border for the Atlantic Coast 
unit and Upper St. Johns River unit should be described as the Clay-
Putnam Counties line as opposed to Palatka.
    Response: We did not make the suggested change because the 
commenter did not provide a citation supporting this change. The 
boundary described in the SAR is the same boundary referenced in the 
2001 Florida Manatee Recovery Plan and FWC's Final Biological Status 
Review of the Florida Manatee (Haubold et al., 2006).
    Comment 8: If addressing implementing regulations, we recommend 
reference to the Florida Manatee Sanctuary Act (Ch. 379.2431(2), 
Florida Statute) as this regulatory and conservation authority provides 
for the management actions as defined in the 2007 FWC Manatee 
Management Plan.
    Response: Although the Florida Manatee Sanctuary Act was referenced 
in the draft SAR in the Status of Stock section, we added another 
reference as suggested in the Stock Definition and Geographic Range 
section of the final revised SAR.
    Comment 9: The minimum population estimate (Nmin) for 
the Florida manatee stock is calculated using the equation for Minimum

[[Page 18575]]

Population Estimate provided in NMFS (2016): Nmin = N/exp 
(0.842 x [ln(1+[CV (N)]\2\)]1/2). We recommend including an 
explanation of what the Minimum Population Estimate implies. For 
example, the Minimum Population Estimate provides a conservative 
estimate of the 20th percentile of the population distribution.
    Response: The recommended explanation is an accurate statement, but 
we did not add additional information to the final revised SAR in 
response to this comment because we do not believe most readers need 
the SAR to provide that detailed of an explanation. Readers wanting a 
more thorough understanding of the basis for the equation for the 
minimum population estimate or what it signifies can refer to the cited 
source for more information.
    Comment 10: The most recent adult-survival-rate analysis for the 
Florida manatee identifies mean adult survival rates of over 97 
percent. It should be noted that these are baseline rates and do not 
include episodic factors affecting survival, including events such as 
red tide and significant periods of cold temperature.
    Response: As with Comment 9, the recommended additional information 
is an accurate statement, but we did not add more explanation to the 
final revised SAR in response to this comment because we do not believe 
most readers need the SAR to provide that detailed of an explanation. 
The SAR notes that the reported rates are baseline mean adult survival 
and reproductive rates that were based on data collected over a 20+ 
year period. Readers wanting a more thorough understanding of how the 
rates are calculated can refer to the cited source for more 
information.
    Comment 11: We request additional research citations for this 
chapter: Reinert et al. 2017: Entanglement in and ingestion of fishing 
gear and other marine debris by Florida manatees, and Bassett et al. 
2020: Quantifying sublethal Florida manatee-watercraft interactions by 
examining scars on manatee carcasses.
    Response: We added a citation to Bassett et al. 2020 in the final 
revised SAR and in the References. Reinert et al. 2017 was already 
cited in the draft SAR, but we added an additional citation to it in 
the suggested section.
    Comment 12: Manatee mortality data are available and verified 
through December 2020 with preliminary mortality data available through 
2021 and much of 2022. We recommend inclusion of this recent data 
within this chapter, including the associated tables, or explanation of 
why the SAR does not report this data.
    Response: We added additional discussion in the SAR to address this 
comment and explain the data range used in the tables. The data 
summarized in the tables and discussed in the SAR are based on 
confirmed mortality data. Preliminary data are not included because 
these data are subject to change as to cause of death and other 
attributes. In discussions of the ongoing UME, the reported total 
number of deaths does include preliminary data (to provide context on 
the scale of the event), but no assessments of these data have been 
made as to cause of death. The mortality and rescue data summarized in 
the SAR include data through 2018, the last full year for which 
confirmed mortality data were available from the FWC at the time this 
report was prepared and submitted to the Atlantic SRG for peer review. 
After peer review, FWC provided confirmed mortality data covering all 
of 2019 and 2020. Due to both the timing of when these data became 
available and to changes FWC made to their data collection protocols, 
these data are discussed but are not included in the tables.
    Comment 13: Manatee mortality should include a description of other 
cause of death (COD) categories, including Verified Not Necropsied and 
Undetermined. Reported data on human-related COD is likely an 
underestimate as there may be cases of human-related death that were 
not quantified if a carcass was not recovered, necropsied, or a COD was 
unable to be determined. We recommend including two columns in table 4 
to distinguish between Other and Undetermined COD categories as opposed 
to ``Other.''
    Response: Descriptions of other causes of death were included in 
the draft SAR, as was a citation to the FWC website that describes all 
the categories; however, we have added additional explanation and 
discussion in the final revised SAR, particularly for the Verified Not 
Necropsied (VNN) category. The draft SAR explained that the cause of 
some deaths cannot be determined and that the true number of deaths 
(total or in any given category) is not known because the number of 
carcasses that are not found or reported is unknown. We did not split 
the ``Other'' category as suggested given the focus of the SAR is on 
human-related deaths; no human-related deaths are included in the VNN 
and Undetermined categories that comprise the ``Other'' category used 
in the SAR.
    Comment 14: The statement referring to carrying-capacity and cited 
as Provancha et al. 2012 does not consider the thermal quality of warm-
water sites. We recommend further discussion on insufficient or non-
dependable warm water as a limiting factor in addition to physical 
constraints such as vegetation.
    Response: Warm-water issues were discussed in the draft SAR in 
sufficient detail, consistent with the requirements of the MMPA. 
Readers wanting a more thorough understanding of potential carrying 
capacity issues can refer to the cited sources for more information.
    Comment 15: We recommend including additional citations on red tide 
effects on manatees: Walsh et al. 2015: Sublethal red tide toxin 
exposure in free-ranging manatees (Trichechus manatus) affects the 
immune system through reduced lymphocyte proliferation responses, 
inflammation, and oxidative stress, and Flewelling et al. 2005: Red 
tides and marine mammal mortalities.
    Response: We added citations to both papers in the final revised 
SAR.
    Comment 16: From information reported by the St. Johns River Water 
Management District, and based on 2021 aerial survey seagrass data, the 
Indian River Lagoon has lost approximately 75 percent of seagrass 
acreage since 2009 with 40 percent loss of seagrass acreage from 2019 
through 2021.
    Response: We did not revise the information contained in the draft 
SAR because the commenter did not provide a supporting citation. 
Although the information included in the SAR is not the same as the 
above comment, the source we cited is recent (2022) and from the same 
agency referred to in the comment, and both descriptions support the 
same finding: that significant seagrass losses have occurred in this 
area.

References

    In accordance with section 117(b)(1) of the MMPA, we include in 
this notice a list of the sources of information or published reports 
upon which we based the revised SAR. The Service consulted technical 
reports, conference proceedings, refereed journal publications, and 
scientific studies prepared or issued by Federal agencies, 
nongovernmental organizations, and individuals with expertise in the 
fields of marine mammal biology and ecology, population dynamics, 
modeling, and commercial fishing practices. These agencies and 
organizations include the Service, the U.S. Geological Survey, the 
National Oceanic and Atmospheric Administration, the Puerto Rico 
Department of Natural and Environmental Resources, the Georgia 
Department of Natural Resources, the

[[Page 18576]]

Florida Fish and Wildlife Conservation Commission, Hubbs Sea World 
Research Institute, the Gulf and Caribbean Fisheries Institute, the 
Caribbean Stranding Network, and Mote Marine Laboratory. In addition, 
the Service consulted publications such as the Journal of Wildlife 
Management, Marine Mammal Science, Marine Pollution Bulletin, Marine 
Technology Society Journal, Wildlife Monographs, Gulf and Caribbean 
Research, Journal of Zoo and Wildlife Medicine, Molecular Ecology, and 
Molecular Ecology Notes, as well as other refereed journal literature, 
technical reports, and data sources in the development of these SARs. A 
complete list of citations to the scientific literature relied on for 
each of these SARs is available on the Federal eRulemaking portal 
(https://www.regulations.gov) under Docket No. FWS-R4-ES-2022-0031 or 
upon request from the Florida Ecological Services Field Office or 
Caribbean Ecological Services Field Office (see FOR FURTHER INFORMATION 
CONTACT).

Authority

    The authority for this action is the Marine Mammal Protection Act 
of 1972, as amended (16 U.S.C. 1361 et seq.).

Signing Authority

    Martha Williams, Director of the U.S. Fish and Wildlife Service, 
approved this action on March 24, 2023, for publication. On March 24, 
2023, Martha Williams authorized the undersigned to sign the document 
electronically and submit it to the Office of the Federal Register for 
publication as an official document of the U.S. Fish and Wildlife 
Service.

Madonna Baucum,
Chief, Policy and Regulations Branch, U.S. Fish and Wildlife Service.
[FR Doc. 2023-06505 Filed 3-28-23; 8:45 am]
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