The 2006 movie, Happy Feet, follows a young emperor penguin as he tries to find a mate despite his lack of singing talent. This kid-friendly film boasts a 7 out of 10 rating on Rotten Tomatoes; yet despite its cute and fluffy outward appearance, an underlying plot of the film is that the penguin’s food supply has been getting smaller and smaller. This, as it turns out (spoiler alert), is due to human overfishing. The impact of overfishing is a major issue in the movie, as well as in real life.
Overfishing is defined as depleting or exhausting a stock of fish by excessive fishing. Excessive fishing is a direct result of supply and demand. Humans demand fish to eat, make pet food, make fish oil supplements, and feed livestock, among other uses. As a result, fish populations are declining. According to a United Nations Food and Agriculture Organization report, 77 percent of world fish stocks are “fully exploited”, or worse (1). A 2015 World Wildlife Fund report found that from 1970 to 2012, populations of marine vertebrates (mammals, birds, reptiles, and fish) declined by 49 percent (2). In other words, their populations are half of what they were 42 years ago. Cape Cod was named by an English explorer who visited in 1602 and noted a “great store of codfish” (3). Guess what fish is now hard to find off of Cape Cod? Cod. We’ve decimated this population to near collapse in just 400 years. This story replays itself in many other regions across the world.
How are we adapting to declining fish stocks?
Given our depleted oceans, the industry has turned to farmed fish. But this unnatural way of raising fish carries its own set of problems (waste management, antibiotic use, pesticide use, etc.). Plus, many farmed fish still require a diet of fish, so wild fish continue to be caught in order to feed the farmed species, sometimes at an inefficient feed conversion ratio of 5:1 (five pounds of wild fish feed produces one pound of farmed fish) (4).
Another adaptation that’s becoming much more common, is that fish are simply mislabeled. As stocks of commonly consumed fish decline, and thus become more expensive, they are often replaced with another species (without the consumer’s knowledge). Oceana conducted the largest seafood fraud investigation from 2010-2012. Through DNA testing they found that 33 percent of fish tested from retail outlets were mislabeled (5). A 2017 investigation also found that 33 percent of seafood species tested were mislabeled (6).
Neither of these address the underlying cause of declining fish populations–our demand for fish. If we truly want to give global fish stocks a chance to recover, we need to significantly reduce our consumption. Many underdeveloped island and coastal populations throughout the world rely on fish as a staple food in their diet. Most of us living in developed countries do not. We are the ones capable of adjusting our diet for the greater good. National Geographic explorer, Dr. Enric Sala, said “The ocean is like a checking account where everybody withdraws but nobody makes a deposit. This is what’s happening because of overfishing”.
- General situation of world fish stocks: United Nations Food and Agriculture Organization (FAO)
- Living Blue Planet Report: Species, habitats and human well-beingCape Cod History
- Global overview on the use of fish meal and fish oil in industrially compounded aquafeeds: Trends and future prospects
- Oceana Study Reveals Seafood Fraud Nationwide
- DNA Barcoding analysis of seafood accuracy in Washington, D.C. restaurants