The Status of the United States Population of Night Shark, Carcharhinus signatus

Carlson, John K. and Cortés, Enric and Neer, Julie A. and McCandless, Camilla T. and Beerkircher, Lawrence R. (2008) The Status of the United States Population of Night Shark, Carcharhinus signatus. Marine Fisheries Review, 70(1), pp. 1-13.

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Official URL: http://spo.nmfs.noaa.gov/mfr701/mfr7011.pdf

Abstract

Night sharks, Carcharhinus signatus, are an oceanic species generally occurring in outer continental shelf waters in the western North Atlantic Ocean including the Caribbean Sea and Gulf of Mexico. Although not targeted, night sharks make up a segment of the shark bycatch in the pelagic longline fishery. Historically, night sharks comprised a significant proportion of the artisanal Cuban shark fishery but today they are rarely caught. Although information from some fisheries has shown a decline in catches of night sharks, it is unclear whether this decline is due to changes in fishing tactics, market, or species identification. Despite the uncertainty in the decline, the night shark is currently listed as a species of concern due to alleged declines in abundance resulting from fishing effort, i.e. overutilization. To assess their relevance to the species of concern list, we collated available information on the night shark to provide an analysis of its status. Night shark landings were likely both over- and under-reported and thus probably did not reflect all commercial and recreational catches, and overall they have limited relevance to the current status of the species. Average size information has not changed considerably since the 1980’s based on information from the pelagic longline fishery when corrected for gear bias. Analysis of biological information indicates night sharks have intrinsic rates of increase (r) about 10% yr–1 and have moderate rebound potential and an intermediate generation time compared to other sharks. An analysis of trends in relative abundance from four data sources gave conflicting results, with one series in decline, two series increasing, and one series relatively flat. Based on the analysis of all currently available information, we believe the night shark does not qualify as a species of concern but should be retained on the prohibited species list as a precautionary approach to management until a more comprehensive stock assessment can be conducted.

Item Type: Article
Title: The Status of the United States Population of Night Shark, Carcharhinus signatus
Personal Creator/Author:
CreatorsEmail
Carlson, John K.
Cortés, Enric
Neer, Julie A.
McCandless, Camilla T.
Beerkircher, Lawrence R.
Refereed: Yes
Journal or Publication Title: Marine Fisheries Review
Volume: 70
Number: 1
Page Range: pp. 1-13
Date: 2008
ISSN: 0090-1830
Issuing Agency: United States National Marine Fisheries Service
Subjects: Fisheries
Management
Item ID: 9700
Depositing User: Patti M. Marraro
Date Deposited: 14 Aug 2012 16:46
Last Modified: 14 Aug 2012 16:47
URI: http://aquaticcommons.org/id/eprint/9700

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