Following a first time assessment of all 61 known species of scombrids (tunas, bonitos, mackerels and Spanish mackerels) and billfishes (swordfish and marlins) for the IUCN Red List of Threatened Species, seven are classified as threatened and at serious risk of extinction.
In addition, four species are listed as Near Threatened, with nearly two-thirds making it to the Least Concern category.
Tunas appear to be at the most risk with five of the eight species in the threatened or Near Threatened catogories, including: Southern bluefin; Atlantic bluefin; Bigeye; Yellowfin and Albacore.
Due to the extremely high economic value of many species, the information should prove invaluable in helping governments make decisions to safeguard these species, and has come about just in time for the 3rd Joint Meeting of the Tuna RFMOs (Regional Fisheries Management Organisations) being held in La Jolla, California, July 11-15.
"This is the first time that fishery scientists, ichthyologists and conservationists have come together to jointly produce an assessment of the threats facing a commercially important group of fishes," says Dr Bruce B. Collette, Chair of the IUCN Species Survival Commission's (SSC) Tuna and Billfish Specialist Group, Senior Scientist of the U.S National Marine Fisheries Service, and lead author of the paper.
"All three bluefin tuna species are susceptible to collapse under continued excessive fishing pressure. The Southern Bluefin has already essentially crashed, with little hope of recovery," says Dr Kent Carpenter, Professor at Old Dominion University, manager of IUCN's Marine Biodiversity Unit and an author of the paper. "If no changes are made to current fishing practices, the western Atlantic Bluefin stocks are at risk of collapse as they are showing little sign that the population is rebuilding following a significant reduction in the 1970s."
Three species of billfishes are in threatened or Near Threatened categories: Blue marlin, White marlin and Striped marlin.
The most efficient way to avoid collapse of fisheries would be to shut the fisheries down, but this method comes with some serious implications.
"Temporarily shutting down tuna fisheries would only be a part of a much needed recovery programme. In order to prevent illegal fishing, strong deterrents need to be implemented," says Jean-Christophe Vié, Deputy Director, IUCN's Global Species Programme. "This new study shows that there is an urgent need for effective management. Scientific findings should not be discarded in order to maintain short-term profit. Marine life and jobs for future generations are both at stake."
Complete results of the tuna and billfish species assessments will be published on the IUCN Red List of Threatened Species in November 2011. As of July 7, 2011, draft assessments are available.
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