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Marine & Environmental Sciences Faculty Articles
Global Phylogeography of the Dusky Shark Carcharhinus obscurus: Implications for Fisheries Management and Monitoring the Shark Fin Trade
ResearcherID
G-4080-2013
Document Type
Article
Publication Title
Endangered Species Research
ISSN
1863-5407
Publication Date
2011
Keywords
Mitochondrial DNA, Phylogeography, Conservation, Mixed stock analysis
Abstract
Genetic stock structure information is needed to delineate management units and monitor trade in sharks, many of which are heavily exploited and declining. The dusky shark Carcharhinus obscurus is a large apex predator that is sought after for its fins and is considered highly susceptible to overexploitation. The International Union for the Conservation of Nature (IUCN) classifies this species as ‘Vulnerable’ globally and ‘Endangered’ in the northwest Atlantic. We make the first assessment of global stock structure of C. obscurus by analyzing part of the mitochondrial control region (mtCR) in 255 individuals sampled from 8 geographically dispersed locations. We found 25 mtCR haplotypes and rejected a null hypothesis of panmixia (analysis of molecular variance, ΦST = 0.55, p < 0.000001), detecting significant differentiation between 3 management units: US Atlantic (USATL), South Africa (SAF), and Australia (AUS). We also found preliminary evidence of population structure between the USATL and southwest Atlantic (Brazil). There were no shared haplotypes between the western Atlantic and Indo-Pacific. These analyses suggest that replenishment of the collapsed USATL management unit via immigration of females from elsewhere is unlikely. Mixed stock analysis (MSA) simulations show that reconstruction of the relative contributions of USATL, SAF, and AUS management units to the Asian fin trade is possible using these mtCR sequences. We suggest avenues for obtaining samples to conduct MSA of the shark fin trade, which could enhance management of dusky sharks and other species that are exploited for their fins.
DOI
10.3354/esr00337
Volume
14
Issue
1
First Page
13
Last Page
22
NSUWorks Citation
Benavides MT, Horn RL, Feldheim KA, Shivji MS and others (2011) Global phylogeography of the dusky shark Carcharhinus obscurus: implications for fisheries management and monitoring the shark fin trade. Endang Species Res 14:13-22
Comments
©Inter-Research 2011