bluefin tuna

Bluefin tuna back in the spotlight

posted by Veronique Koch on 11 April 2012

Recently there has been a lot of talk about Atlantic bluefin tuna, but not because of any new stock assessments or a change to their endangered status. Bluefin are the subject of the new reality series, “Wicked Tuna”, National Geographic’s answer to the Discovery Channel’s successful “Deadliest Catch”. The show, set in Gloucester, Massachusetts, thrives on its volatile characters that fight tooth and nail to catch the biggest tunas of the day.

 

This has caused some controversy due to the fact that bluefin is known to be the poster child of overfished species. Carl Safina, ocean advocate, wrote several posts about this, as did Lee Crockett of the Pew Environment Group, and the Center for Biological Diversity. The demand for bluefin tuna, particularly for the sushi and sashimi markets, has driven the stocks down between 29% and 51% (according to the IUCN), but the astronomical prices offered for its flesh keep the fisheries going.

 

National Geographic defends its decision to feature Atlantic bluefin tuna fishing, saying it is also including a conservation message in their series by interviewing world-renowned experts in the field. But one could argue that simply emphasizing the adrenaline-rush and high-dollar payoff of tuna fishing (with some of the Gloucester fish bringing in $20,000 for the Japanese export market) would undermine any efforts to protect the species through the brief interviews with the experts. In the words of Wicked Tuna’s Paul Hebert: “My advice for anyone who wants to come $%#ing tuna fishing? You’re out of your mind if you don’t!”

 

Bluefin tuna has been nicknamed the “cocaine of the sea” because of the high prices it can bring in for fishermen. Nat Geo says that the New England tuna fishery is an artisanal one, i.e. it is not the huge industrial fisheries that has hit the fish population so hard but rather a “one man, one fish” fight which is relatively less damaging.

 

True, these fishermen fight for hours at a time to bring in one tuna one hook and line, with relatively little bycatch. Over the course of a one-hour episode, a handful of boats probably bring in roughly 5 or 6 fish total. This is considerably less destructive than the purse seine nets used in industrial fishing to encircle a school of tuna and scoop them up, together with whichever fish or other marine animals happen to be nearby.

 

But the fact is that these tuna are in big trouble globally. In the last 60 years, 90 percent of the ocean’s top predators, including tuna, have disappeared. And while these impressive fish have evolved incredible adaptations to swim as fast and as far as they do, we keep wanting more and more of their delectable flesh.

 

Their stiff, torpedo-shaped bodies and perfectly shaped fins are built for speed. Their specialized, warm-blooded circulatory systems allow them to swim in colder waters, develop more efficient muscular systems and cover an incredible migratory range that they have.

 

But basic facts about the bluefin tuna’s expansive migration ranges and spawning habits are still a mystery according to the Pew Charitable Trusts. These are important variables to consider when determining whether a fishery is sustainable or not.

 

To make sure that the fishery is sustainable, we need to know that the fish can reproduce at least as quickly as we are catching them. Also, given the great distances that Atlantic bluefin tuna migrate (thousands of miles per year across the ocean) it is important to remember that there is a high degree of sharing between the Eastern and Western Atlantic fishing stocks and fishermen. These fish are being hit from both sides of the ocean.

 

As long as countries like Japan (which consumes 80% of all tuna caught today) offer tens of thousands of dollars for a single fish (or in the extreme case of one 593 lb specimen sold in January of this year, $736,000) there is no incentive for fishermen to give up.

 

Raising tuna on fish farms is thought of as a way to help ease the pressure on wild stocks. Tuna ranching, as it is commonly referred to, is more than anything a loophole around the current catch quotas allowed for tuna fishermen now. It differs from other forms of aquaculture in that it takes all of its fish from the wild (oftentimes before the tuna have spawned even once). It catches them (using big nets and sometimes even spotter planes) before fattening them up in pens.

 

Many bluefin tuna are fattened in floating ranches before they are killed. Photo Credit: Paul Hilton/Greenpeace

 

 

Only time will tell if Wicked Tuna can keep up its wicked ratings. Hopefully, the take-away message for audiences from the show is that although this is a more sustainable way to harvest wild Atlantic bluefin tuna from the sea, the difficulty the fishermen have catching them is a peek into how dire the state of the tuna fishery is. If it costs a boat $3000 just to go out and fish, catching one minimum size tuna only just covers their costs. How long can the New England bluefin tuna fishery last? At the very least, perhaps the show will start an important dialogue with the public about choosing where their fish comes from.

 

Photo: Pew Charitable Trusts

2 thoughts on “Bluefin tuna back in the spotlight

  1. FHB says

    The prices quoted are exaggerated as most bluefins return much less. Also many commercial fishermen work
    together finding these fish in a large ocean.
    I wonder at our regulators reasoning for allowing the harvest of small bluefin tuna. Sport fishermen do far more damage taking these smaller fish, which never spawned.

  2. FishDoc says

    You bring up some very valid points. We are only now recognizing the potential impacts of harvest related to recreational angling, much of which is not accounted for by fisheries managers and policy makers. This is especially concerning if the fish being targeted and harvested are immature and have not yet had a chance to spawn and contribute to the maintenance of the population. Another important consideration is that even catch-and-release (whether voluntary or mandated through size regulations, for instance) can result in post-release mortality or sub-lethal effects like reduced growth rates and spawning potential. Given that recreational angling is a huge economic engine in developed and developing countries, it is important to determine the best practices for catch-and-release so that undersized fish can survive the experience, grow, reproduce, and then potentially either be harvested later in life or recaptured in a catch-and-release fishery. This way each fish has the ability to contribute to the economy in several ways and/or at several times in its life (not to mention the ecological services many fish provide to aquatic ecosystems). One thing to remember in the debate about ‘size’ is that the number of eggs produced by female fish is positively related to body size – meaning that the bigger the fish, the proportionally greater capacity she has to contribute to the population. As such, the overall goal of fisheries managers is to allow enough small fish to eventually grow into big fish PLUS keep enough big fish in the population to so that the rate of replenishment (known as recruitment) can be maximized. This gets tricky from the perspective of commercial and recreational anglers since for a given unit of effort (time/money) it is much more appealing to catch a big fish than a small one, even if the point is to just catch-and-release.

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