Marlowe Hood AFP Yahoo News 8 Jul 11;
The reference organisation for the conservation status of Earth's animals and plants said for the first time Thursday that most species of tuna are urgently in need of protection.
Five of eight tuna species are now threatened or nearly threatened with extinction due to overfishing, according to the Red List of Threatened Species, compiled by the Swiss-based International Union for the Conservation of Nature (IUCN).
The report is being released ahead of a July 11-15 meeting in La Jolla, California of the world's five regional fisheries management organisations (RFMOs), intergovernmental groups set up to insure that tuna fisheries remain sustainable.
Southern bluefin tuna stocks have already crashed with little hope of recovery, resulting in a status of "critically endangered", the IUCN reported.
Atlantic bluefin -- with populations in both the east and west fished to the edge of viability -- is now officially "endangered".
All bluefin tuna species "are susceptible to collapse under continued excessive fishing pressure", said Ken Carpenter, a professor at Old Dominion University in Norfolk, Virginia and the head of the IUCN's Marine Biodiversity Unit.
Other tuna species under sharp pressure from high-tech factory ships that comb international waters in search of ever-dwindling stocks include bigeye, classified as vulnerable, along with yellowfin and albacore, both ranked as "near threatened".
"This is the first time that fishery scientists, ichthyologists (fish specialists) and conservationists have come together to jointly produce an assessment of the threat facing a commercially important group of fishes," said Bruce Collette, a senior scientist at the US National Marine Fisheries Service and head of the IUCN's Tuna and Billfish Specialist Group.
All told, the new peer-reviewed classification, based on a study published Thursday in the US journal Science, assessed 61 species of tunas, bonitas, mackerels and billfishes, a group that includes swordfish and marlins.
Among billfishes, blue and white marlins are deemed vulnerable, while striped marlin has been classified as near threatened.
Up to 90 percent of many large, open-water fish have been depleted by industrial-scale fishing over the last half-century, and marine scientists warn that continued harvesting could lead to irreversible declines of some species.
Because many are at the top of the food chain, their disappearance could also disrupt delicately balanced ecosystems.
In the case of tuna species, "the most efficient way to avoid collapse is to shut down the fisheries until stocks are rebuilt to healthy levels", the researchers concluded.
"Scientific findings should not be discarded in order to maintain short-term profit," they added, a clear jab at RFMOs that have in the past consistently ignored the advice of their own scientific committees.
Five main species of tuna make up the annual worldwide catch of 4.0 to 4.5 million tonnes.
Destined mainly for supermarket shelves, skipjack (Katsuwonus pelamis) accounts for 60 percent of the total.
Yellowfin (Thunnus albacares) and bigeye (Thunnus obesus) comprise 24 and 10 percent of the global tuna market respectively.
Thunnus alalunga, better known as albacore, follows with five percent, while Atlantic Bluefin (Thunnus thynnus), highly prized in Japan for sashimi and sushi, is less than one percent.
More than half of tuna species at risk of extinction, say conservationists
IUCN study shows three species are threatened with extinction, while two more will be under threat without action to help them
Press Association guardian.co.uk 7 Jul 11;
Five out of the eight tuna species are at risk of extinction, conservationists warned today, as they called for urgent action to tackle over-fishing.
The latest assessment for the International Union for Conservation of Nature (IUCN) showed that three species are threatened with global extinction, while two more will be under threat without action to help them.
A study, published in the journal Science, which looks at all "scombrid" fish, which include tuna and mackerel, and billfishes, which include swordfish and marlins, found that seven of the 61 known species were under threat.
The study said some of the species were heavily over-fished, with little interest in conserving them because of the high commercial value of the catch.
There were also difficulties in regulating the multinational fisheries which exploit the stocks.
IUCN experts warned that all three bluefin tuna species – southern, Atlantic and Pacific – were susceptible to collapse because of pressure from fishing for the high-value fish.
Southern bluefin tuna are already critically endangered, the highest category of risk, and Atlantic bluefin are endangered, the assessment for the IUCN red list of threatened species found.
Bigeye tuna are vulnerable to extinction, while yellowfin and albacore tuna are close to being under threat, or will be threatened with extinction if conservation measures are not put in place to turn their fortunes around.
Among other species, blue and white marlin were both assessed as being vulnerable to extinction, putting them in the third of the three most serious categories for threatened species and at risk of dying out globally.
Dr Kent Carpenter, manager of IUCN's marine biodiversity unit and an author of the study, said: "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.
"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."
Most of the economically valuable species such as tuna are at the top of the marine food chain, and their decline could have negative impacts on other species.
They are also long-lived, with slower reproductive rates which means populations take longer to recover.
Last year, proposals were made to have Atlantic bluefin tuna listed as endangered under the Convention on International Trade in Endangered Species (Cites), temporarily stopping the trade in the species.
But attempts to list bluefin tuna, a sushi delicacy in Japan, as an "appendix I" species were defeated by a large majority of countries at the Cites meeting in March 2010.
The study published today said the only way to save southern and Atlantic bluefin tuna was to shut down the fisheries until stocks were rebuilt, although to do so would encourage illegal fishing.
Strong deterrents would be needed, such as controlling international trade in tuna through the Cites scheme, the scientists suggested.
Jean-Christophe Vie, deputy director of the IUCN's global species programme, said: "Temporarily shutting down tuna fisheries would only be a part of a much-needed recovery programme.
"Scientific finding should not be discarded in order to maintain short-term profit. Marine life and jobs for future generations are both at stake."
Increased protection urgently needed for tunas
IUCN 7 Jul 11;
For the first time, all species of scombrids (tunas, bonitos, mackerels and Spanish mackerels) and billfishes (swordfish and marlins) have been assessed for the IUCN Red List of Threatened Species™. Of the 61 known species, seven are classified in a threatened category, being at serious risk of extinction. Four species are listed as Near Threatened and nearly two-thirds have been placed in the Least Concern category.
The results show that the situation is particularly serious for tunas. Five of the eight species of tuna are in the threatened or Near Threatened IUCN Red List Categories. These include: Southern Bluefin (Thunnus maccoyii), Critically Endangered; Atlantic Bluefin (T. thynnus), Endangered; Bigeye (T. obesus), Vulnerable; Yellowfin (T. albacares), Near Threatened; and Albacore (T. alalunga), Near Threatened.
This new information will be invaluable in helping governments make decisions which will safeguard the future of these species, many of which are of extremely high economic value, and is a timely input for the 3rd Joint Meeting of the Tuna RFMOs (Regional Fisheries Management Organizations) 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 NOAA's National Marine Fisheries Service, and lead author of the paper.
There is growing concern that in spite of the healthy status of several epipelagic fish stocks (those living near the surface), some scombrid and billfish species are being heavily overfished, and there is a lack of resolve to protect against overexploitation driven by high prices. Many populations are exploited by multinational fisheries whose regulation, from a political perspective, is exceedingly difficult.
“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 (Makaira nigricans), Vulnerable; White Marlin (Kajikia albida), Vulnerable; and Striped Marlin (Kajikia audax), Near Threatened.
Most of the long-lived economically valuable species are considered threatened. They mature later than short-lived species and their reproductive turnover is longer, and as such recovery from population declines takes more time. As these scombrids and billfishes are at the top of the pelagic food web, population reductions of these predators may cause significant negative effects on other species that are critical to the balance of the marine ecosystem and that are economically important as a source of food.
The future of threatened scombrids and billfishes rests on the ability of RFMOs and fishing nations to properly manage these species. Southern and Atlantic Bluefin populations have been so reduced that the most efficient way to avoid collapse is to shut down the fisheries until stocks are rebuilt to healthy levels. However, this would cause substantial economic hardship and hinder the ability of RFMOs to control fishing because of the increased incentive for illegal fishing that would be created under these circumstances.
“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.”
The recovery of fish stocks is possible through reducing fishing-induced mortality rates to well below the maximum sustainable yield (MSY), as shown in the case of the highly valued eastern population of the Atlantic Bluefin. Recently exploited at three times the MSY, a decrease in the total allowable catch and stricter monitoring and compliance measures have led to recent catch reductions of almost 75% over the past few years. This will enable the species to recover to sustainable levels as long as the current fishing controls are maintained.
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