Showing posts with label bluefin tuna. Show all posts
Showing posts with label bluefin tuna. Show all posts

Friday, October 21, 2011

141% more tuna is traded than is allowed to be caught

Depressing figures do not even take account of black market
October 2011: The amount of eastern Atlantic bluefin tuna traded on the global market last year exceeded the official quota by a staggering 141 per cent, according to the latest analysis.

The figure shows a rapidly worsening situation. It is the result of a study commissioned by the Pew Environment Group and compares to one two years ago in which the quota was exceeded by 31 per cent. And it could be just the tip of the iceberg, as these figures do not even account for ‘black market' bluefin that is missing from official databases.

Stronger enforcement neededThis analysis highlights the gap between the quota for Atlantic bluefin tuna allowed to be caught in the Mediterranean Sea and the eastern Atlantic Ocean and the amount traded on the international market during the period of 1998-2010.

In 2008, in response to plummeting bluefin tuna populations in the Mediterranean, member governments of the International Commission for the Conservation of Atlantic Tunas (ICCAT), the organisation responsible for managing tuna and similar species in the Atlantic and Mediterranean, adopted stronger enforcement and trade measures. These included lower catch limits and a paper-based documentation system designed to more accurately record the amount of bluefin caught and traded. But the new study shows that despite those efforts, significant problems with illegal and unreported fishing remain.

In light of the findings,
The Pew Environment Group urges ICCAT member governments to take immediate action at their annual meeting in next month. Specifically, Pew is calling for improving compliance with bluefin tuna catch quotas by ensuring that an electronic documentation system is in place for the 2012 fishing season.

‘We need to track fish from sea to plate'‘The paper-based catch documentation of the bluefin trade is rife with fraud and misinformation,' said Lee Crockett, who directs Atlantic bluefin tuna conservation at the Pew Environment Group. ‘An electronic system would provide more accurate information that can be easily shared and cross-checked instantly. Such a programme should also include a physical bar code for each bluefin, which could be easily administered and would not be cost prohibitive. This would allow the fish to be tracked from sea to plate.'

Most bluefin tuna caught in the Mediterranean are destined for ‘ranches'. Juvenile bluefin that have yet to reproduce are netted and transferred to these pens, where they are fattened for months and sometimes years before being killed and sold on the global market. The electronic catch documentation programme would help track the amount of fish in ranches.

‘Tuna ranching in the Mediterranean makes it exceedingly difficult to accurately track the number of bluefin caught,' said Roberto Mielgo Bregazzi, a bluefin tuna trade expert who conducted the analysis. ‘These offshore bluefin tuna fattening ranches are part and parcel of the problem of underreporting and non-reporting of caught fish.'


http://www.wildlifeextra.com/go/news/bluefin-quotas2011.html

Saturday, October 8, 2011

Tuna washes ashore on Isle of Mull

We thought it must be a porpoise'
October 2011: A tuna has been found washed up on the shore of Laggan Sands, on the Isle of Mull, prompting an investigation by the Hebridean Whale and Dolphin Trust (HWDT).

Morven Summers, volunteer coordinator at HWDT, said: ‘We were a wee bit dubious at first and thought that the reporter may have mistaken a porpoise, however when we arrived at Laggan Sands we were shocked to see the huge fish on the shore.'

It's believed that the fish is a bluefin tuna; a large, torpedo-shaped fish that can travel at speeds of up to 43 miles per hour and weighs, on average, 550lb, although much larger specimens are not uncommon.

'Seeing the fish up close was fantastic'The Mull tuna measured 1.8 metres long. Brain Swinbanks, chairman of the Tobermory Harbour Association, added: ‘Seeing the fish up close was fantastic, I would guess that the "Mull tuna" weighed about 150lbs.'

Atlantic bluefin tuna spawn in the Mediterranean Sea, but are highly migratory and tagged individuals have been tracked swimming from North American to European waters several times a year.

Although not many consider the waters off the west coast of Scotland to play host to such a fish, historically tuna did frequent these waters.

Dr Clive Fox, from the Scottish Association of Marine Science in Oban, explains: ‘Bluefin tuna are rare in our waters but not unprecedented, indeed there used to be a commercial and sport fishery for them before the war.'

Already evidence of bluefin tuna migrating to UKIn fact, evidence of bluefin tuna making an annual migration to UK waters goes back a few hundred years. Brain Swinbanks, chairman of the Tobermory Harbour Association, added: ‘The British rod and line record for Blue Fin Tuna is 851lb caught in the North Sea in 1933 by Mr Mitchell-Henry fishing from a ship's rowing boat 50 miles off shore and alongside the Herring Fleet.

‘A decline in the stocks of herring resulted in a decline in migratory tuna which originally came from the Mediterranean migrating all round the west coast of Scotland.'

In September 1989, a 400lb tuna was reported caught close to the Isle of Lewis. Unfortunately the tuna carcass was too decomposed for full analysis, however the fish's otoliths (ear bones) will be recovered and from these the age of the fish can be determined.
http://www.wildlifeextra.com/go/news/tuna-mull.html

Friday, October 29, 2010

WWF welcomes EU Commissioner’s call for big cut in Mediterranean bluefin tuna catches

Last chance for Mediterranean tuna

October 2010. WWF, the global conservation organization, has welcomed the EU Commissioner for Maritime Affairs and Fisheries Maria Damanaki's call for a significant cut in catches of bluefin tuna in the Mediterranean and East Atlantic ahead of the European Union's leadership role at a major fisheries management meeting next month in Paris, France.

EU Commissioner Damanaki has announced her support for a substantial decrease in total allowable catch of East Atlantic bluefin tuna next year. Spanish Member of the European Parliament and Vice-President of the Greens, Raül Romeva i Rueda, confirmed Commissioner Damanaki's urge for a "substantial decrease" in catches at the meeting.

WWF is calling for this to form a fundamental part of the EU's position at the meeting of International Commission for the Conservation of Atlantic Tunas (ICCAT) members on 17-27 November 2010 in Paris, France.

Recovery plan
A new recovery plan for East Atlantic bluefin tuna must be agreed at the Paris ICCAT conference. In the coming days the EU Commission and Member States will formally agree the EU's negotiating mandate for that meeting.

"Commissioner Damanaki is laying out what could be a possible rescue plan for the Atlantic bluefin tuna fishery based on science and not politics" said Tony Long, Director of WWF's European Policy Programme in Brussels. "We call on Member States to follow this lead to secure a long-term future for a sustainable artisanal fishery and a thriving marine ecosystem. The EU Commissioner is showing a way forward that counteracts strong pressure from short-term business interests."

Current stock is only 1/3 of sustainable levels
A recent scientific assessment of East Atlantic bluefin tuna by ICCAT scientists has shown that stock size is only one third of sustainable levels, and that only a total fishing quota of less than 6,000 tonnes per year might allow the tuna stock to rebuild by 2020 with a probability of over 60 per cent. The scientists also urged ICCAT to be especially precautionary this year, given the high uncertainty in data available - a result of the poor quality of reporting related to rife illegalities.

The EU, including all Member States, is legally obliged through its Marine Strategy Framework Directive to immediately establish measures aimed at achieving recovery of fish stocks to sustainable levels by 2020 at the latest.

Purse seine fishery
Besides cutting total annual catch to below 6,000 tonnes, WWF is also calling on the EU and other ICCA members to suspend the industrial purse seine fishery - responsible for the current catastrophic situation of the stock - and to establish no-fishing zones in the six known spawning grounds of bluefin tuna in the Mediterranean Sea.

"This package of measures gives at least a chance of recovery to East Atlantic bluefin tuna," said Dr Sergi Tudela, Head of Fisheries at WWF Mediterranean. "It is high time to show the world that Europe, with its historical role in willingly allowing the depletion of tuna stocks, is ready for a U-turn by leading on the recovery of Atlantic bluefin."

http://www.wildlifeextra.com/go/news/iccat-2010.html

WWF welcomes EU Commissioner’s call for big cut in Mediterranean bluefin tuna catches

Last chance for Mediterranean tuna

October 2010. WWF, the global conservation organization, has welcomed the EU Commissioner for Maritime Affairs and Fisheries Maria Damanaki's call for a significant cut in catches of bluefin tuna in the Mediterranean and East Atlantic ahead of the European Union's leadership role at a major fisheries management meeting next month in Paris, France.

EU Commissioner Damanaki has announced her support for a substantial decrease in total allowable catch of East Atlantic bluefin tuna next year. Spanish Member of the European Parliament and Vice-President of the Greens, Raül Romeva i Rueda, confirmed Commissioner Damanaki's urge for a "substantial decrease" in catches at the meeting.

WWF is calling for this to form a fundamental part of the EU's position at the meeting of International Commission for the Conservation of Atlantic Tunas (ICCAT) members on 17-27 November 2010 in Paris, France.

Recovery plan
A new recovery plan for East Atlantic bluefin tuna must be agreed at the Paris ICCAT conference. In the coming days the EU Commission and Member States will formally agree the EU's negotiating mandate for that meeting.

"Commissioner Damanaki is laying out what could be a possible rescue plan for the Atlantic bluefin tuna fishery based on science and not politics" said Tony Long, Director of WWF's European Policy Programme in Brussels. "We call on Member States to follow this lead to secure a long-term future for a sustainable artisanal fishery and a thriving marine ecosystem. The EU Commissioner is showing a way forward that counteracts strong pressure from short-term business interests."

Current stock is only 1/3 of sustainable levels
A recent scientific assessment of East Atlantic bluefin tuna by ICCAT scientists has shown that stock size is only one third of sustainable levels, and that only a total fishing quota of less than 6,000 tonnes per year might allow the tuna stock to rebuild by 2020 with a probability of over 60 per cent. The scientists also urged ICCAT to be especially precautionary this year, given the high uncertainty in data available - a result of the poor quality of reporting related to rife illegalities.

The EU, including all Member States, is legally obliged through its Marine Strategy Framework Directive to immediately establish measures aimed at achieving recovery of fish stocks to sustainable levels by 2020 at the latest.

Purse seine fishery
Besides cutting total annual catch to below 6,000 tonnes, WWF is also calling on the EU and other ICCA members to suspend the industrial purse seine fishery - responsible for the current catastrophic situation of the stock - and to establish no-fishing zones in the six known spawning grounds of bluefin tuna in the Mediterranean Sea.

"This package of measures gives at least a chance of recovery to East Atlantic bluefin tuna," said Dr Sergi Tudela, Head of Fisheries at WWF Mediterranean. "It is high time to show the world that Europe, with its historical role in willingly allowing the depletion of tuna stocks, is ready for a U-turn by leading on the recovery of Atlantic bluefin."

http://www.wildlifeextra.com/go/news/iccat-2010.html

Saturday, September 18, 2010

Tuna Imperiled by Overfishing, Oil Spill Clears First Hurdle to Endangered Species Act Protection

From: Center for Biological Diversity
Published September 17, 2010 01:20 AM

SAN FRANCISCO— The National Marine Fisheries Service announced Thursday it will consider protecting Atlantic bluefin tuna under the Endangered Species Act. The decision is scheduled to be published in the Federal Register on Sept. 21 and comes in response to a Center for Biological Diversity’s petition last May to protect the tuna, in dramatic decline because of overfishing and habitat degradation, including from the BP oil spill. The Center issued a notice of intent to sue the agency earlier this week for failing to respond to the petition within the legally required timeline.

“As a result of this decision, the bluefin tuna could become the first species considered for federal protections in the wake of the Deepwater Horizon oil spill,” said Catherine Kilduff, an oceans program attorney at the Center. “Unfortunately, tuna epitomize the precarious position of many Gulf of Mexico species. Tuna were already on the brink of extinction before the oil spill from severe overfishing; then the spill drowned their breeding grounds in oil during spawning season.”

Overfishing of Atlantic bluefin tuna has caused a more than 80-percent decline from what the population would be without fishing pressure. The sushi market keeps prices for tuna high — a single individual sold for $177,000 in the fish market this year — and encourages illegal and unreported fishing. In 2007, fishermen reported catching 34,514 tons of eastern Atlantic bluefin tuna, exceeding the allowable catch by about 5,000 tons. Scientists estimated the actual catch was likely about double the reported amount.

“Our voracious appetite for sushi propelled tuna into a jaw-dropping decline, and BP’s disastrous spill only made their plight more urgent,” said Kilduff. “Tuna are in urgent need of the protections of the Endangered Species Act, which has a proven track record of success in protecting imperiled wildlife.”

The bluefin, a majestic fish weighing close to a ton and reaching 13 feet, is among the fastest of all species, capable of speeds over 55 miles per hour. There are two imperiled populations of Atlantic bluefin tuna, one that spawns in the Gulf of Mexico and another that spawns in the Mediterranean. The petition seeks endangered status for both populations, which are intensely overfished. Protection under the Endangered Species Act would require federal agencies such as the Bureau of Ocean Energy Management, Regulation and Enforcement to avoid jeopardizing the bluefin tuna in permitting offshore drilling. Additionally, protections would safeguard critical habitat and ban the importation of bluefin.

For more information about the Center’s bluefin tuna conservation campaign, visit: http://www.biologicaldiversity.org/species/fish/Atlantic_bluefin_tuna/index.html.

http://www.enn.com/press_releases/3497

Tuna Imperiled by Overfishing, Oil Spill Clears First Hurdle to Endangered Species Act Protection

From: Center for Biological Diversity
Published September 17, 2010 01:20 AM

SAN FRANCISCO— The National Marine Fisheries Service announced Thursday it will consider protecting Atlantic bluefin tuna under the Endangered Species Act. The decision is scheduled to be published in the Federal Register on Sept. 21 and comes in response to a Center for Biological Diversity’s petition last May to protect the tuna, in dramatic decline because of overfishing and habitat degradation, including from the BP oil spill. The Center issued a notice of intent to sue the agency earlier this week for failing to respond to the petition within the legally required timeline.

“As a result of this decision, the bluefin tuna could become the first species considered for federal protections in the wake of the Deepwater Horizon oil spill,” said Catherine Kilduff, an oceans program attorney at the Center. “Unfortunately, tuna epitomize the precarious position of many Gulf of Mexico species. Tuna were already on the brink of extinction before the oil spill from severe overfishing; then the spill drowned their breeding grounds in oil during spawning season.”

Overfishing of Atlantic bluefin tuna has caused a more than 80-percent decline from what the population would be without fishing pressure. The sushi market keeps prices for tuna high — a single individual sold for $177,000 in the fish market this year — and encourages illegal and unreported fishing. In 2007, fishermen reported catching 34,514 tons of eastern Atlantic bluefin tuna, exceeding the allowable catch by about 5,000 tons. Scientists estimated the actual catch was likely about double the reported amount.

“Our voracious appetite for sushi propelled tuna into a jaw-dropping decline, and BP’s disastrous spill only made their plight more urgent,” said Kilduff. “Tuna are in urgent need of the protections of the Endangered Species Act, which has a proven track record of success in protecting imperiled wildlife.”

The bluefin, a majestic fish weighing close to a ton and reaching 13 feet, is among the fastest of all species, capable of speeds over 55 miles per hour. There are two imperiled populations of Atlantic bluefin tuna, one that spawns in the Gulf of Mexico and another that spawns in the Mediterranean. The petition seeks endangered status for both populations, which are intensely overfished. Protection under the Endangered Species Act would require federal agencies such as the Bureau of Ocean Energy Management, Regulation and Enforcement to avoid jeopardizing the bluefin tuna in permitting offshore drilling. Additionally, protections would safeguard critical habitat and ban the importation of bluefin.

For more information about the Center’s bluefin tuna conservation campaign, visit: http://www.biologicaldiversity.org/species/fish/Atlantic_bluefin_tuna/index.html.

http://www.enn.com/press_releases/3497

Saturday, July 17, 2010

Sushi-hungry Japan sells monster tuna

A monster tuna caught off Japan turned heads at a Tokyo fish market Friday, where the 445 kilogram (981 pound) bluefin -- the biggest caught here since 1986 -- sold for 3.2 million yen (36,700 dollars).

"Many of the people who work at the market have never seen a tuna that big," said an official of the Tokyo Metropolitan Government, which runs the Tsukiji fish market, the world's biggest seafood market.

The fish, which was auctioned at 7,200 yen per kilogram, had already been gutted and cleaned of its gills, meaning it must have weighed more when it was caught off Nagasaki prefecture this week, the official said.

"It is extremely rare to see a tuna heavier than 400 kilograms," he said.

The biggest Japanese tuna sold at Tsukiji was a 496-kilogram beast caught in April 1986 -- but the biggest tuna from the world's oceans to be sold here was a Canadian fish caught in 1995 weighing 497 kilograms.

Decades of overfishing have seen global tuna stocks crash, pushing some Western nations to call for a trade ban on endangered Atlantic bluefin tuna.

Japan consumes three-quarters of the global bluefin catch, a highly prized sushi ingredient, known in Japan as "kuro maguro" (black tuna) and dubbed by sushi connoisseurs as the "black diamond" because of its scarcity.

A piece of "otoro" or fatty underbelly can cost 2,000 yen (22 dollars) at high-end Tokyo restaurants.

http://news.ph.msn.com/weird-news/article.aspx?cp-documentid=4223047

Tuesday, June 1, 2010

Animals Most Threatened By The Gulf Oil Spill (Via Herpnet)

Animals Most Threatened By The Gulf Oil Spill
Melissa Breyer, Care2 Tue May 25, Yahoo News

As images of lifeless black-slicked birds and limp sea turtles begin to flood the media, it is becoming apparent just how catastrophic the Deepwater Horizon oil spill in the Gulf of Mexico is becoming. No one can predict how long it will continue and just how devastating this disaster might prove to be.

One thing is clear: The fragile ecosystems of the Gulf of Mexico are at great risk. Adding to the tragedy is that this is an incredibly vital area for countless numbers of species that come for refuge to this specific stretch of the country to breed, nest, spawn, feed, and rest during migration. Peak migration and breeding times are late-April through mid-May. It really could not be worse timing.

As noted in The New York Times, "even the frantic preparations to protect the most vulnerable coastlines likely will not prevent devastating harm to key species as the Gulf of Mexico oil spill hits shore at the worst possible time for migration and breeding."

The U.S. Fish and Wildlife Service said the oil spill could affect up to 20 national wildlife refuges, and four covering more than 70,000 acres are in immediate concern.

Which animals are most threatened by this nightmare of an environmental disaster? Here is a round-up of some of those most in peril.

Brown Pelicans
The brown pelican has not had an easy time of it. The gracefully gangling birds were only removed from the endangered species list last year, and there is a major population, around 34,000 of them, currently nesting in the Gulf at the Breton National Wildlife

Diving birds are very susceptible to oil spills because they come into direct contact with the oil. A bird's feathers overlap to trap air and provide the bird with warmth and buoyancy.

Birds that come in contact with an oil slick may get oil on their feathers and lose their ability to stay waterproof, they may ingest oil while trying to clean their feathers or when they try to eat contaminated food, and they may suffer long-term reproductive effects.

Brown pelicans were once the victims of hunters seeking feathers for millinery -- which led to the birth of the National Wildlife Refuge System more than 100 years ago when President Theodore Roosevelt created the first refuge at Pelican Island in Florida.

In 1970, brown pelicans were officially declared an endangered species when their population was decimated by the use of DDT.

Sea Turtles
Of the seven remaining species of sea turtles known today, five of those species are in the Gulf. The oil spill area is one of the only foraging grounds for the most endangered species of the bunch, the Kemp's ridley turtle, which is in its peak nesting season.

One of its two primary migration routes runs south of Mississippi. Loggerhead turtles, also endangered, feed in the warm waters in the Gulf between May and October.

The seven species that can be found today have been around for 120 million years (longer than the dinosaurs) -- and many of these species live up to 80 years.

Dolphins
Several dolphin species routinely inhabit the northern Gulf, and already 12 bottlenose dolphins have been found dead due to the the oil spill, reports Yahoo! News.

When marine mammals come to the surface to breathe, they may inhale hydrocarbon vapors that can result in lung injuries; oil that comes in contact with the animals' sensitive mucous membranes and eyes may produce irritations.

Young cetaceans may be injured due to ingestion of oil from contaminated teats when nursing; and there may be long-term chronic effects as a result of migration through oil-contaminated waters.

Shellfish And Crabs
According to The New York Times, the delta estuary is also the breeding ground for a lot of shellfish and crabs, says LuAnn White, director of Tulane University's Center for Applied Environmental Public Health. "All of those are at risk for being damaged," she said. "That estuary area is responsible for the breeding for about 40 percent of the aquatic life that's in the Gulf, [so] you could be affected not only the wildlife that lives in that area, but the whole Gulf."

Coastal marshes are key to the life cycle and development of Louisiana shrimp and blue crab; both staples of the local seafood industry. Inshore shrimp season will open in mid-May, while brown shrimp are in their post-larval and juvenile development stages.

The coastal waters around the very tip of Louisiana's boot-shaped coast are home to some of the most productive oyster farms in the country. Oils and hydrocarbons are toxic to oysters.

Unfortunately, hydrocarbons can persist in coastal sediments for months or even years. The New York Times notes that Louisiana oyster farmers, many of whom barely scrape by with high fuel costs and global competition, could have trouble weathering the oil spill if their harvests are affected.

If chemicals such as dispersants are used to respond to a spill, there may be an increased potential for tainting of shellfish by increasing the concentration of oil in the water column. This can affect humans in areas that have commercial and recreational fisheries.

Shorebirds
Shorebirds such as plovers, sandpipers, and oystercatchers are nesting or preparing to nest on beaches and barrier islands in Louisiana. Those that build their nests on the ground and feed on invertebrates are vulnerable to oil coming ashore.

Many shore birds are also making their spring migration through the area, and habitually stop along the Gulf Coast to rest and feed. Shorebirds currently coming from wintering grounds in South America to breeding grounds in boreal forests and arctic tundra congregate in large numbers on beaches and barrier islands during the last week of April and first week of May -- as chance would have it, the two weeks of the entire year that migration peaks.

Experts are very concerned for a number of different bird groups and species based on the uncanny timing and the possible scope of the impact.

North Atlantic Bluefin Tuna
Unfortunately for the North Atlantic bluefin tuna, their meat is regarded as exceedingly delicious, and overfishing throughout their range has driven their numbers to extremely low levels. Critically endangered (according to the IUCN Red List), their stocks have already fallen about 90 percent since the 1970s.

The tuna return between mid-April mid-June from vast distances to spawn in an area very close to the spill, where the water is warm and full of nutrients flowing from the Mississippi River.

Spawning Habitat of Bluefin Tuna in Gulf of Mexico: Critical Area Intersects Deepwater Horizon Oil Spill

ScienceDaily (May 31, 2010) — Electronic tagging and fisheries catch data have revealed pronounced differences in preferred habitat of Atlantic bluefin tuna and yellowfin tuna in the Gulf of Mexico, despite their close ancestry, according to a new study published today in the peer-reviewed journal PLoS ONE. Bluefin tuna return to the same regions of the Gulf of Mexico during spring months to spawn. The bluefin are selecting a particular habitat along the slope waters of the Gulf of Mexico, which has unique oceanographic properties that are predictable and can be seen from satellites. Yellowfin tuna are more widely distributed throughout the warm Gulf waters and occupy the region throughout the year.

"The bluefins' habitat requirements are relatively exact so we can predict with reasonable accuracy where bluefin tuna are likely to be spawning at any given time based on oceanographic data continually being gathered by satellites and weather buoys," said lead author Steven Teo of the University of California at Davis. "This is in stark contrast to yellowfin tuna, which exhibit much more generalized environmental preferences." The fidelity to breeding areas over time detected in this study is reminiscent of salmon returning to their natal stream to spawn.


Bluefin tuna are among the most valuable fish in global markets. The International Commission for the Conservation of Atlantic Tunas (ICCAT, http://www.iccat.int) currently manages the Atlantic bluefin tuna as two distinct populations, with western Atlantic spawners of the Gulf of Mexico forming a distinct population genetically from the eastern spawners of the Mediterranean Sea. The western Atlantic stock has suffered a significant decline in spawning stock biomass since 1950, and a 20-year rebuilding plan has failed to revive the population or the North American fishery. The failure of the Gulf of Mexico spawning population to rebuild, as well as the scope of illegal and under-reported catches -- particularly in the Mediterranean Sea -- are of such major concern that the species was recently considered by the United Nations for endangered species listing in March of 2010.

Targeted bluefin fishing has been banned in the Gulf for over twenty years, but bluefin continue to be captured accidentally on pelagic longlines, often resulting in mortality. The study shows that bluefin tuna are captured in the Gulf of Mexico from January through June each year, and the highest pelagic longline catch rates are in April and May, during the bluefin spawning season.

The authors compared environmental preferences and spatio-temporal distributions of bluefin and yellowfin tuna as revealed by pelagic longline catch rates and scientific tagging cruise conducted by the Stanford University and Monterey Bay Aquarium team coupled with oceanographic data sets. Drawing on these data, a model was developed to determine the relative probability of catching bluefin and yellowfin tuna at a given place and time. This model showed that there are two major hotspot regions within the Gulf where bycatch occurs -- one in the eastern Gulf of Mexico to the north of the Loop Current, and the other in the western Gulf of Mexico. Both regions are along the slope where the shallow continental shelf depth changes rapidly to the deep sea. It is within these hotspots that bluefin tuna prefer to spawn in circular, swirling water masses called "cyclonic eddies." These eddies are more productive and slightly cooler than surrounding warm Gulf ocean currents. Yellowfin tuna, however, are much more widely dispersed throughout the Gulf of Mexico throughout the year.

These findings indicate that it would be possible to utilize spatial management techniques to protect western Atlantic bluefin tuna on their breeding grounds in the Gulf of Mexico without compromising the yellowfin tuna fishery, which could be carried out in other areas during the critical bluefin tuna breeding times.

Unfortunately, these findings also give cause for concern in light of the recent Deepwater Horizon oil spill. "Both catch data and electronic tags indicate the Gulf of Mexico along the continental shelf is the preferred habitat of this majestic fish. I think it is amazing how precisely we can predict where the bluefin are. Unfortunately their spawning habitat overlaps the Deepwater Horizon oil accident site, and the timing of the spill coincides with the time when we expect them to be there spawning" said senior author Dr. Barbara Block of Stanford University.

Funding for this study was provided by the Lenfest Ocean Program, the Tag-A-Giant Foundation, the David and Lucile Packard Foundation, the Monterey Bay Aquarium Foundation, the National Oceanographic and Atmospheric Administration and the Disney Foundation.