Last year more than 90 million metric tons of fish was harvested worldwide. This is the equivalent to the weight of the population of China. The Food and Agriculture Organization of the United Nations reports that 30% of the world’s fish stocks are overfished (harvest rates are greater than fishing mortality rates) and 60% are fully fished (harvest rates are approaching maximum sustainable yield). We are on the verge of losing several species of fish as well as endangering entire ecosystems. With the loss of these fish comes the loss of a valuable food source and income streams for millions of people.
The posterfish for the overfishing epidemic might be the bluefin tuna. It is estimated that the bluefin tuna population is under 3% of its historic population. This is mainly due to countries like Japan, South Korea, and the United States exceeding fishing quotas for several years running. Most of the world’s bluefin tuna is consumed in Japan– upwards of 80% of the world’s catch. Bluefin toro sushi is highly sought after and consumers are willing to pay top dollar. One sushi restaurateur paid $650,000 for a 212 kg bluefin in January, 2017. To feed this ferocious appetite for bluefin, 70% of Pacific bluefin are less than a year old when harvested; 95% less than three. These harvesting practices are decimating the bluefin tuna population. Some speculate that population has fallen past the point of recovery.
Fishing for Northern Atlantic cod had been a way of life for people of the region for 500 years. But in the 1960’s something new came to the Atlantic seaboard– fishing trawlers equipped with radar became commonplace. 30 years later, in 1992, Canada declared a moratorium on the Northern Cod fishery. Atlantic Cod had been fished to near extinction. The northern cod population was at 1% of its historic numbers. 35,000 people lost their jobs due to the collapse of the fishery and 20 years later the cod population has not recovered and the moratorium remains in place.
Wild salmon numbers have also been on the decline. The World Wildlife Fund estimates that the salmon population has decreased by 50% over the past 20 years. This is mainly due to commercial overfishing, mostly in the Norwegian Sea. Habitat loss has also hurt salmon, as many spawning rivers have been dammed. Wild Atlantic salmon are no longer seen in the rivers of Connecticut which has over 3,000 dams.
Is aquaculture the answer? Farmed fish has been touted as the answer to overfishing, but fish farms come with their own set of problems. In terms of tuna, no. Tuna can not be farmed large scale. The majority of farmed tuna are merely juvenile bluefins that are caught wild and then fattened in offshore pens.
There has been success in farming salmon and cod. Over 2 million tons of Atlantic salmon are farmed each year and farmed Atlantic cod saw some limited success with 25,000 tons farmed in 2010. There are several concerns abouts about farmed fish however. Farmed fish are much more prone to disease and parasites than wild fish. A percentage of farm raised fish escape hatcheries each year and could pose health risks when introduced to wild populations. The waste produced from fish farms also have a significant impact on surrounding ecosystems. Lastly, salmon require almost 2 pounds of protein for every 1 pound of salmon. To feed massive salmon fish farm billions of “trash fish” are caught every year and ground into fish feed.
Tilapia has been successfully farmed in Africa and Asia and is a suitable, sustainable replacement for whitefish. But the same qualities that make tilapia an ideal fish for aquaculture means that it is incredibly invasive. Here in the US tilapia has taken over freshwater bodies throughout the southeast and many states are attempting to regulate it.
Would you change your fish eating habits? Would you try eating different types of fish? The Monterey Bay Aquarium Seafood Watch has an app that gives the latest recommendations for seafood and sushi. Would you use it?
Greenberg, Paul, 1967-. Four Fish : the Future of the Last Wild Food. New York :Penguin Press, 2010. Print.