Overfishing and the Bluefin Tuna
Ian Somerhalder Foundation
Overfishing is a serious problem the world’s oceans are facing as it is depleting the oceans of some of their most important inhabitants – fish.
What is overfishing?
It is exactly what it sounds like, the over fishing of fish. Overfishing occurs when commercial and/or non-commercial fishing depletes the fish population at a rate that makes it difficult, if not impossible, for the remaining fish to continue to breed, replenish, and sustain the population.1
Overfishing is not a new phenomenon. For instance, the whale population was almost destroyed in the 1800s when they were regularly fished for their blubber. And, many fish including the Atlantic cod and sardines were harvested to near extinction in the mid 1900s. What started as a regional depletion became a global problem by the late 20th century.2
During the middle of the 20th century, protein-rich foods become high in demand, and to meet this demand, governments around the world increased their fishing capacity. Consumers became accustomed to having access to a wide selection of fish species at low prices. This only perpetuated the problem of overfishing specific fish species. 2
Currently, almost eighty percent of the world’s fisheries are either depleted or in a state of collapse. Worldwide, ninety percent of the stocks of large predatory fish are already gone. This could lead to the loss of entire species of fish as well as entire ecosystems. The entire ecological unity of the oceans is at risk of collapse. Scientists believe that if things continue as they are, many fish stocks will be completely gone within the next twenty-five years.3
Bluefin Tuna at Risk of Depletion
Of all the fish, the Bluefin Tuna faces the greatest risk of depletion due to overfishing. The Atlantic Bluefin Tuna is considered to be one of the most beautifully colored fish in the world. Atlantic Bluefin Tuna are metallic blue and silver-white, coloring that helps to camouflage them. They are torpedo shaped and usually around 6 ½ feet long and weigh about five hundred pounds. These fish are warm-blooded, a rarity among fish, and live in both the cold waters of Iceland and the warm waters of the Mediterranean Sea and the Gulf of Mexico. Their migratory patterns are nothing short of ambitious as they have been tracked to swim from North American waters to European waters numerous times a year.
Unfortunately, overfishing has driven these gorgeous and ambitious fish to critically low levels. The Western Atlantic Bluefin Tuna populations have declined by eighty percent since the 1970s, and it is estimated that as few as 25,000 mature Bluefin Tuna remain.6 Additionally, the population of Eastern Atlantic Bluefin Tuna has decreased by sixty percent in the last decade!5 However, in January 2012, the National Oceanic and Atmospheric Administration ruled that the Bluefin Tuna would not be protected under the Endangered Species Act but would be considered a species of “concern”.4
But it is not too late to protect the Bluefin Tuna! It is believed that if the leaders and fishermen of the world work together to halt the practice of overfishing, it may be possible to bring the Bluefin Tuna back from the brink of extinction. If put in place, the guidelines outlined below could raise the population of the Bluefin Tuna:
• Long-term planning for sustainability: fisheries at their best are a renewable and endless supply of protein but due to current economic pressures, this type of planning is being ignored instead of implemented‚
• Setting quotas for the amount of fish that are caught: these quotas need to be based on scientific estimates for the size of the fish stock‚
• Developing more efficient means to control and manage the unintentional catching, killing, and disposal of fish, crustaceans, and other ocean life that is not a part of the target catch
• Using the correct mesh size in fishing nets: this measure ensures that (1) the fish caught are of the right age and (2) to eliminate the accidental catching of other fish
• Creating international agreements: these agreements would limit catches so that fish stocks can be safeguarded
• Expand marine reserves: marine reserves, a place where no fishing can take place, currently cover only one percent of the world’s oceans and should be expanded to cover up to forty percent of the world’s oceans. 7 Also, the most important part of the fish’s ecosystems, their nursing grounds, the sea floor, unexplored habitats, and corals, need full protection from fisheries
• Monitoring fishermen: this would ensure that (1) fishermen do not catch more fish than they are allowed and (2) they do not fish in off limit areas
Something Easy YOU Can Do
Do not forget that one of the most important things you can do to help is to know what you eat! Try to avoid eating seafood, but if you must, limit the amount that you eat. When you do eat seafood, educate yourself about what you are eating. You can check for sustainable seafood in your area by visiting http://www.msc.org/where-to-buy/product-finder, or http://www.montereybayaquarium.org/cr/cr_seafoodwatch/download.aspx. If you are eating tinned tuna, make sure it is dolphin safe and avoid buying species that appear on the seafood red list as these species are at high risk of being unsustainable.
- See more at: http://www.isfoundation.com/news/creatures/overfishing-and-bluefin-tuna#sthash.RIVOjDK2.dpuf
The Pacific Bluefin Tuna Is Going, Going…
The valuable—and flavorful fish is a favorite of sushi chefs around the world. But the very popularity of bluefin tuna could mean its doom.
By Bryan Walsh
It wasn’t an easy number to find. Earlier this week the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean—seriously, that’s the name—released the latest assessment (PDF) of the Pacific bluefin tuna population. The bluefin tuna is the tiger of the sea—in more ways than one. It’s a top of the food chain predator that can grow to over 1,000 lbs. and swim at speeds above 50 mph. In captivity—you can see them at the great Monterey Bay Aquarium in northern California—they shimmer like sports cars. Unfortunately for the tuna, they also happen to be delicious—the flesh of the bluefin tuna is prized by sushi chefs in the high-end restaurants of Japan. Just last week, a 489-lb. bluefin was sold at a fish auction in Tokyo for a record $1.76 million—or about $3,600 per pound.
So it’s not surprising that the Pacific bluefin tuna—as well as its cousins in the Atlantic—are the subject of single-minded hunts by fishermen wherever they are found. But it’s always been difficult to determine just how rapidly the bluefin is being fished out—in part, possibly, because countries like Japan that do most of the fishing and most of the consumption of bluefin don’t really want those numbers made public. It’s a strategy that should be familiar from a lot of environmental policy battles.
But back to that scientific report. Buried deep in the highly technical language of the Pacific Bluefin Tuna Stock Assessment is a number: 0.036. That’s the depletion ratio for one of the computer simulation runs done that tries to model the effect of fishing on the bluefin tuna population. By itself, 0.036 doesn’t seem to mean much—unless you do some more math. In the simulations, the number 1 represents the estimated population of the bluefin tuna before we started fishing. 0.036 is what’s left now. Convert that to a percentage, and you get 96.4%. Which means that by the best guesses of scientists, the Pacific bluefin tuna population has declined by 96.4% since we began fishing it decades ago. 96.4%. No wonder that bluefin sold in Tokyo was so valuable. There may not be many fish left in the sea.
I should point out that I didn’t actually do the math on this one myself. That’s well beyond my English degree. Instead I called up Amanda Nickson, who directs global tuna conservation at the Pew Environment Group, who helped me put the numbers in perspective. She pointed out the even the most optimistic model in the report estimated that the bluefin population had fallen by 94%, and the most pessimistic put the figure at 97.9%. Even worse, as Nickson told me, “at least 90% of the fish being caught have not yet reached reproductive age, which obviously undermines their ability to reproduce.” So not only are we decimating the population of the bluefin, but we’re not even giving them the chance to rebuild their numbers.
Pew’s recommendation, echoed by many other environmental groups and scientists, is that the Pacific bluefin tuna fishery should be suspended, at least until there’s more effective management that might prevent overfishing. “There are no sustainable catch limits,” says Nickson. “The countries involved have been doing this for decades despite the science telling them that they shouldn’t.” There has been some progress in recent years. While there is virtually no management in the fisheries of the western Pacific, last June there were limits adopted for the first time for bluefin tuna fishing in the eastern Pacific. Those conservation measures actually caused the fishery to close early in August when the limits were exceeded. It’s a start, at the very least—and it should also include a pledge by diners to eschew bluefin tuna just as they would any other endangered species. But if we don’t do much more, one of the most majestic fish in the sea may disappear for good.
Read more: http://science.time.com/2013/01/11/the-pacific-bluefin-tuna-is-almost-gone/#ixzz2Y0IUMxYd