Time for fishing bans to protect threatened tuna stocks says report
A new study says that more work needs to be done to protect some of the most economically important fish species which are exploited across international boundaries, making protecting them more difficult.
The study of tuna and billfish populations by a team including professor John Graves of the Virginia Institute of Marine Science was the first to use the methods of the International Union for the Conservation of Nature (IUCN) which keeps the Red List, the globally recognised register of endangered species.
Graves' work is published in Science magazine's Policy Forum and categorised tuna and billfish species with the Red List classifications, from "least concern" to "near threatened," "vulnerable," "endangered," "critically endangered," "extinct in the wild," and "extinct." Those species classified as "vulnerable," "endangered," and "critically endangered," are considered threatened.
Seven of the 61 species surveyed from international fishery data were considered threatened with four more 'near threatened' and 39 in the 'least concern' category.
The most threatened species are southern bluefin tuna, Atlantic bluefin tuna, bigeye tuna, blue marlin, white marlin, and two species of Spanish mackerels.
Overfishing is largely to blame according to Graves. Already this year a single bluefin tuna has hit a price of $400,000 dollars. Because tuna and billfish mature slowly, it takes some time for them to breed their way out of any population slump.
The best way to protect these species is, says Graves, to ban fishing of the most endangered species - the Southern and Atlantic bluefin tuna. Graves would also like the protection of the Convention on International Trade in Endangered Species extended to these fish.
But, with such economic interests involved it will require a great deal of political will to put these protections in place although previous examples have shown that controlling fisheries can bring tuna, mackerel, and other billfish species back to sustainable numbers.
Top Image: Rare bluefin tuna fish on auction in Japan at Tokyo's Tsukiji Fish Market - Credit: © ET - backpacker snaps