Populations of many of the world’s pelagic, or open ocean, shark and ray species are declining. Like most sharks, these species are known to be susceptible to overfishing due to low reproductive rates. Pelagic longline fisheries for tuna and swordfish catch significant numbers of pelagic sharks and rays and shark fisheries are also growing due to declines in traditional target species and the rising value of shark fins and meat. Yet, a lack of data has prevented scientists from conducting reliable population assessments for most pelagic shark and ray species, hindering effective management actions.
Dr. Colin Simpfendorfer and the Lenfest Ocean Program convened an international expert working group to estimate the risk of overfishing for twelve species caught in Atlantic pelagic longline fisheries under the jurisdiction of the International Commission for the Conservation of Atlantic Tunas (ICCAT). The scientists conducted an integrated risk assessment designed for data-poor situations for these sharks and rays. Their analysis indicated that bigeye thresher, shortfin mako and longfin mako sharks had the highest risk of overfishing while many of the other species had at least moderately high levels of risk. Based on these results, the scientists developed recommendations for limiting or prohibiting catch for the main pelagic shark and ray species taken in ICCAT fisheries.
You may also read a summary of this research in the Lenfest Ocean Program Research Series report, Atlantic Sharks at Risk.