Sleek, powerful tunas and billfishes that ply the open ocean garner some of the highest prices of any fish. In January, a single bluefin tuna fetched a record $396,000 at a Tokyo auction. Yet wild fish populations pay a still higher price for such exorbitant demand: the threat of extinction.
The first assessment of an entire group of commercially valuable marine species found that the most threatened fish are generally the ones reeling in the most money, including bluefin tuna and bigeye tuna. The authors applied the criteria of the International Union for the Conservation of Nature (IUCN) Red List, a framework used to assign a conservation status to plants and animals around the world. The study appeared in the July 15 issue of Science.
“This use of a widely used standard for commercial fishes, this is a first,” said lead author Bruce Collette of the National Marine Fisheries Service in an interview with mongabay.com. While regional fisheries managers typically only look at a portion of a fish’s distribution, Collette says, “We looked at the species on a worldwide basis.” Collette coordinated an international team that analyzed all 61 species of scombrids (a group including tunas, bonitos and mackerels) and billfishes (which include swordfish, sailfish and marlins). They listed each species in one of six IUCN categories. Nearly two-thirds of the species in this diverse group were classified as species of “least concern,” the mark of healthy populations.
However, the consortium of 33 authors listed seven species as “vulnerable,” “endangered,” or “critically endangered,” the three labels that raise a conservation red flag. The authors noted that five of these species are tunas and billfishes that can take a long time to reproduce, and have high economic value: southern bluefin tuna, Atlantic bluefin tuna, bigeye tuna, blue marlin and white marlin.
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http://news.mongabay.com/2011/1109-ucsc_loury_billfish_tuna.html