Conservation of Porbeagle Sharks (Lamna nasus) Worldwide by Species and Population DNA Forensic Testing

Conservation of Porbeagle Sharks (Lamna nasus) Worldwide by Species and Population DNA Forensic Testing

The porbeagle shark (Lamna nasus) is an oceanic species inhabiting the temperate North Atlantic and most of the southern oceans. The high commercial value of its fins has led to severe population depletion in the North Atlantic from overfishing. The population status of southern hemisphere porbeagles, however, is unknown due to lack of fisheries monitoring. Due to mounting concerns about fishing impacts, this shark was placed on the IUCN Red List of Threatened Species in 2007. However, an international petition to get porbeagle sharks listed on CITES (Convention on International Trade in Endangered Species) to require worldwide monitoring of trade in its body parts was denied, partly due to lack of information on the status of its southern populations. Given that the shark fin market is supplied from worldwide sources, a DNA test that can identify porbeagle body parts and also distinguish between northern and southern hemisphere porbeagles is necessary to assess the level of trade in and fishing pressure on its populations. In my study, I have investigated the global diagnostic applicability of a species-specific, nuclear locus-based PCR primer developed earlier in Dr. Shivji’s laboratory by testing it on a worldwide set of porbeagles (100 southern and 100 northern hemisphere animals). Additionally, I am investigating the optimal PCR conditions to achieve reproducible discrimination of northern and southern hemisphere populations based on mitochondrial DNA, hemisphere-specific primers. Finally, I have sequenced the DNA of the nuclear ITS2 locus to determine if genetic signatures discriminating populations within each hemisphere are present.