[Federal Register Volume 80, Number 124 (Monday, June 29, 2015)]
[Notices]
[Pages 36974-36975]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-15809]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XD969
Stock Status Determination for Atlantic Highly Migratory Atlantic
Smooth Dogfish Shark and the Gulf of Mexico Smoothhound Sharks Complex
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice.
-----------------------------------------------------------------------
SUMMARY: This action serves as a notice that NMFS, on behalf of the
Secretary of Commerce (Secretary), has determined that the Atlantic
smooth dogfish shark (Mustelus canis) and the Gulf of Mexico
smoothhound shark complex, which is comprised of Atlantic smooth
dogfish, Florida smoothhound (M. norrisi), and Gulf smoothhound (M.
sinusmexicanus), are not overfished and overfishing is not occurring.
FOR FURTHER INFORMATION CONTACT: Andrew Rubin or Karyl Brewster-Geisz
by phone at 301-427-8503.
SUPPLEMENTARY INFORMATION:
Background
Atlantic smooth dogfish, Florida smoothhound, and Gulf smoothhound
sharks are managed under the authority of the Magnuson-Stevens Fishery
Conservation and Management Act. NMFS manages all shark species, except
for spiny dogfish (Squalus acanthias), under the 2006 Consolidated
Atlantic Highly Migratory Species (HMS) Fishery Management Plan (FMP)
and its amendments.
NMFS recently assessed the status of these species for the first
time using the Southeast Data, Assessment, and Review (SEDAR) process.
The final stock assessment (SEDAR 39) was finalized and peer reviewed
in March 2015.
Data from tagging and genetic research in SEDAR 39 support the
existence of two distinct Atlantic and Gulf of Mexico stocks of smooth
dogfish separated by peninsular Florida. Therefore, smooth dogfish was
treated as two separate stocks, one in the Atlantic region and one in
the Gulf of Mexico region.
Additionally, because smooth dogfish are the only species of
smoothhound sharks occurring in the Atlantic region, the scientists
conducted a stock assessment for only this species in the Atlantic
region. However, because all three species occur in the Gulf of Mexico,
and given the difficulty with distinguishing among and identifying the
individual species of smoothhound sharks occurring in the Gulf of
Mexico region, the scientists treated all three smoothhound species
(smooth dogfish, Florida smoothhound, and Gulf smoothhound) as a single
smoothhound shark complex within the Gulf of Mexico region.
All documents and information regarding SEDAR 39 can be found on
the SEDAR Web page at http://sedarweb.org/sedar-39.
Atlantic Region
For Atlantic smooth dogfish, the scientists used a length-based
age-structured stock assessment model. This was the first HMS shark
stock assessment conducted within the SEDAR process to utilize this
type of modeling framework. The Atlantic smooth dogfish assessment
implemented spawning stock fecundity (SSF), which was used as a proxy
for biomass, natural mortality (M), steepness of the Beverton-Holt
stock-recruitment relationship, and the selectivity patterns using the
same methods as in previous HMS shark assessment.
Two selectivity patterns were explored for the main targeted
gillnet fishery (dome-shaped and asymptotic). The use of these two
selectivity patterns resulted in two alternative base model
configurations being evaluated. Based on diagnostic results, the
scientists recommended that the dome-shaped functional form be selected
as the base model. The peer reviewers found this base model to be an
appropriate methodology.
For this base model, the stock assessment scientists explored seven
sensitivity scenarios. All seven model runs found that SSF in 2012
(SSF2012), was greater than SSFMSY
(SSF2012/SSFMSY ranged from 1.96 to 2.81 vs. 2.29
in the base model) and that F2012 was less than
FMSY (F2012/FMSY ranged from 0.61 to
0.99 vs. 0.79 in the base model). Projection results for the base model
configuration indicated that levels of fixed removals less than or
equal to 550 (1000s of sharks) resulted in at least a 70 percent
probability of maintaining SSF above SSFMSY during the years
2013-2022. Projections for the seven sensitivity scenarios resulted in
a range of fixed removals from 350 to 850 (1000s of sharks) with at
least a 70 percent probability of maintaining SSF above
SSFMSY during the years 2013-2022.
The peer reviewers found it is likely that the Atlantic smooth
dogfish stock is not overfished, and overfishing is not occurring based
on the base model and range of associated sensitivities. The peer
reviewers indicated that the range of sensitivities appropriately
captured the uncertainty regarding the states of nature and the
potential implications for the reference points. However they cautioned
about inferences drawn about stock status because of the level of
uncertainty associated with the stock-recruitment relationship and
uncertainty in the catches, and noted that the fishing level for the
most recent year is close to FMSY for some sensitivity runs. Overall,
the peer reviewers determined the stock assessment to be based on the
best scientific information available. Based on these results, NMFS
determined that the status of smooth dogfish is not overfished and
overfishing is not occurring.
Gulf of Mexico Region
The model structure for the Gulf of Mexico smoothhound shark
complex was different than the Atlantic stock of smooth dogfish because
of the need to combine life history data for all three
[[Page 36975]]
species. The scientists combined this data using a life table to
calculate the mid-point biological values between the species. They
then used a state-space Bayesian surplus production model that
implemented a Schaefer production model in a Bayesian framework. The
peer reviewers found this model to be appropriate and robust. The
reviewers noted issues could occur if the biology and population
dynamics differed significantly but they did not believe this was an
issue for the current assessment.
In addition to the base model, the assessment scientists ran a
number of sensitivities. All sensitivities found that the number of
sharks in 2012 (N2012), which was the proxy used for biomass
for this model, was greater than NMSY (N2012/
NMSY ranged from 1.68 to 1.83 vs. 1.78 in the base model)
and the exploitation rate in 2012 (H2012), which was the
proxy used for fishing mortality in this model, was less than
HMSY (H2012/HMSY ranged from 0.07 to
0.35 vs. 0.18 in the base model). Projections under varying catch
levels conducted with the base model and sensitivities reflecting
plausible states of nature, except the low catch scenario which was not
deemed plausible, indicated that the 2012 catch could be increased by a
factor of 4 and still allow for less than a 30 percent probability of
the stock being overfished during any of the 10 years in the projection
horizon. Similarly, the projected scenarios indicated that the 2012
catch could be increased by a factor of 2, 3, or 4 and still allow for
less than a 30 percent probability of overfishing occurring during any
of the 10 years in the projection horizon.
The peer reviewers found the Gulf of Mexico smoothhound complex is
most likely neither overfished, nor undergoing overfishing. The peer
reviewers noted that the reliability of the stock status determination
is dependent on the accuracy of the shrimp trawl bycatch estimates for
these species and suggested that NMFS explore alternative catch streams
to help assess this uncertainty. Nonetheless, the review panel believed
that the model and associated sensitivities captured the main
uncertainties associated with the assessment. The review panel
considered the base model and corresponding sensitivity runs the best
scientific information available. Based on these results, NMFS
determined that the status of the Gulf of Mexico smoothhound shark
complex is not overfished and overfishing is not occurring.
Dated: June 23, 2015.
Jennifer M. Wallace,
Acting Director, Office of Sustainable Fisheries, National Marine
Fisheries Service.
[FR Doc. 2015-15809 Filed 6-26-15; 8:45 am]
BILLING CODE 3510-22-P