Global genetic inventory of the silky shark:

Outlining stock structure for a species heavily impacted by commercial fishing

Principal Investigators: Derek Kraft, Melanie Hutchinson, Brian Bowen

Silky sharks (Carcharhinus falciformis) occur in all tropical and subtropical oceans waters and are subject to the second highest elasmobranch harvest on the planet. Their habitat overlaps with commercial tuna fisheries, and they account for over 90% of the shark bycatch in tropical purse seines of the western and central Pacific. Silky sharks are also one of the most exploited species in the shark fin trade. As a result, this formerly abundant species has declined by >85% in the last 20 years and was recently listed as vulnerable by International Union for Conservation of Nature (IUCN). Despite this dramatic population crash, there is little information on genetic stock structure to identify this basic units of wildlife management. This project provides the global genetic inventory of silky sharks. Samples were collected by scientific observers aboard commercial fishing vessels from across the entirety of the silky sharks range. Samples were analyzed using high-throughput sequencing technology to illuminate large portions of the genome, allowing the detection of small scale genetic structure across the globe. These results will outlines global stock structure and allow for stock by stock management strategies to be implemented, which is critical for managers to help conserve this heavily harvested pelagic shark.

© 2019 Hawai'i Community Tagging Program

Created by: Maria Harvey