Friday, February 10, 2017

Harvesting sharks could be key to saving them

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.
                                         

New research, appearing in the February 6 issue of Current Biology2, 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.

Indeed, by definition, exploiting a resource sustainably requires whole animal use, Simpfendorfer explains. In the case of MSC-certified Atlantic dogfish, the heads become lobster and crab bait; back meat becomes British fish and chips; belly flaps are a German delicacy; liver supplies nutraceuticals; fins and tails headline east Asian soup; and leftovers become agricultural fertilizer, says Massachusetts-based attorney John Whiteside, Jr., who helped east coast U.S. dogfish fisheries achieve MSC status.

But for sustainable shark fishing to work, its products have to be labeled and traceable back to a well-managed source—a requirement that very few of the sustainably harvested fins currently on the market now meet. Traceability depends on careful management of product “chain of custody” with specific information carried through from capture vessel to retailer. Ideally the products have a closed chain of custody, meaning no uncertified products come in from the sidelines, explains Glenn Sant, Fisheries Trade Programme Leader at TRAFFIC International, the wildlife trade monitoring group co-founded by World Wildlife Fund and the IUCN, who was not part of the study. “Industries have been doing this for a long time,” he observes, with bar codes making traceability of products easy and cheap. Traceability challenges are not technological. They lie in gaining sufficient transparency to discern whether the fishery had adequate management within the product’s country of origin.