February 7, 2017 — Sharks and their relatives face an existential crisis unprecedented in their 420 million years on the planet. A global trade in products from these animals fuels the capture of tens of millions of individuals a year. Strong demand combined with poor fishery regulation and high levels of incidental catch have resulted in many populations being overfished, with some now facing extinction.
Many activists argue a total ban on shark fishing is the only solution to slow or halt the decline. But a 2016 study found the majority of shark researchers surveyed believe sustainable shark fisheries are possible and preferable to widespread bans. Many reported they knew of real-world examples of sustainable shark fisheries. But a global roundup of empirical data exploring which species are being fished sustainably was lacking.
New research, appearing in the February 6 issue of Current Biology, is filling that gap, and the findings bolster the idea that around the world, some sharks are being fished sustainably. Nicholas Dulvy, a marine conservation biologist at Simon Fraser University in British Columbia, and shark ecologist Colin Simpfendorfer of James Cook University in Australia recently examined global stock assessments of 65 shark populations of 47 species. They found 39 of the populations, representing 33 different species, are fished sustainably—that is, they are harvested at levels that allow them to remain stable in size and not edge toward extinction. Although these 33 species account for only a small fraction of the world’s sharks, rays and their kin the chimeras (collectively referred to as sharks), which in total number more than 1,000, they are proof of concept that sustainable shark fishing is possible.