Overfishing Bluefin tuna is becoming one of the most serious and popular topics in the fishing industry, and in different cultures around the world. However, this problem is not one developed by this generation alone, this has been an issue for several decades, and now the tuna populations around the world are declining to dangerously low levels, nearly being listed as an endangered species. The Bluefin tuna are among the most targeted species by the fishing industry for their unmatched size and flavor, and are extremely popular in the sushi industry.
There are three main species of the Bluefin: Pacific, Atlantic/Mediterranean, and Southern. Until around 1970, all species of the Bluefin tuna were considered a nuisance fish because it was oily and unpleasant to eat. In 2015, all of these Bluefin species are suffering from overfishing, approaching the point of no return. Specifically the Atlantic and Pacific bluefin have been plagued by the overfishing stemming from the global sushi market. There are thousands of food miles put on these extraordinary fish, as they are caught all around the world, frozen, flown to the Japan markets, and then shipped again to buyers all around the globe. These methods are contributing to global population depletion and creating a serious need for stark changes in policy, consumption, and harvesting methods if the world population wants to keep this fish in the oceans.
There many factors that contribute to the population decline outside of the basic market demand. Overfishing Bluefin comes from unsustainable fishing methods as well as loopholes within the current market management strategies. There are still many issues with under-reporting catches, using illegal spotting equipment, selling of quotas, and transshipping that are are allowing the Bluefin tuna population to continue to struggle. Not only is this causing issues among the adult population, but the effects are trickling down to younger Bluefin tuna as well. As the larger fish are being caught, the baseline for a “good” catch is shifting downward to younger, smaller tuna. This shifting baseline is causing another multitude of problems, the most serious being the direct and drastic loss of spawning biomass. This is such a serious problem, because now not only are the adult tuna being diminished, but the spawning tuna that are responsible for recovering the population are no longer available, meaning there are less eggs produced every year.
This loss in Bluefin biomass can likely be attributed the the traditional harvesting techniques that promote unsustainable catches. There are four main fishing techniques used to catch Bluefin tuna. Purse seining is among the most popular, along with longline fishing and surface trolling. The fourth method is basic rod and reel fishing, but this is not very popular in the commercial fishing industry because of its inefficiency. There are issues surrounding all three of these methods including large amounts of bycatch, which leads to an unsustainable industry affecting not only tuna, but other species as well, and the fact that many tuna good tuna that are caught can be lost because these methods can be harmful/tragic to the health of the fish.
There are efforts being made around the world to try to reduce this serious problem. The most popular of which is fish ranching. This harvesting method is designed to restore the tuna population (and other fish species) by capturing them from the wild and raising them in a controlled environment until the are of market size. This can be a more sustainable harvesting method if it is performed correctly, but there are issues of disease and other medical problems as with any other CAFO infrastructure. However, if the waste of the fish and feeding can be maintained at a sustainable level, ranching tuna can be an alternative harvesting method to help the Bluefin tune recover as the demand for the sushi market continues to increase.
Matt Brantley is a senior Environmental Studies major at Davidson College. He plays offensive line on the varsity football team and is a member of Phi Delta Theta fraternity. At Davidson, Matt is also involved in other organizations including Fellowship of Christian Athletes, Davidson College Sportsman Society, and the Student-Athlete Sustainability Council.