The environmental impact of eating tuna

With its delicious taste and agreeable texture, tuna is a favorite option for either a snack or meal choice. A nutrient-rich food, this sleek and streamlined species is among the most commercially valuable fish on the planet. And therein lies the problem. Existing levels of tuna fishing are unsustainable, which could drive the fish to extinction. And despite its super healthful benefits, consuming too much tuna can actually be dangerous for you. So, should we still be eating tuna?

Click through and reel in what you need to know about this powerful, agile, and endangered fish.

Popular food

Tuna is the most popular fish in the American diet, second only to shrimp as a favored seafood. In Japan, too, enormous quantities of tuna are consumed daily. And tinned tuna remains the workaday fish gobbled up by millions across the developed world. Indeed, there are lots of good reasons to eat tuna, but there are also plenty of good reasons not to eat tuna.

Tuna species

Did you know that there are 15 different species of tuna fish? Only five, however, can be described as true tuna. These belong to the genus Thunnus.

Albacore tuna

One of the smaller tuna species, albacore tuna are bullet-shaped and always on the move. They are commonly found in the Atlantic, Pacific, and Indian oceans, as well as the Mediterranean Sea.

Bigeye tuna

Bigeye tuna call the open waters of all tropical and temperate oceans home, but not the Mediterranean Sea. Long and streamlined, the species is highly migratory, swimming continuously over large distances.

Atlantic bluefin tuna

The Atlantic bluefin is native to both the western and eastern Atlantic Ocean, as well as the Mediterranean Sea. It's one of the largest, fastest, and most strikingly colored of all the world’s fish—and one of the most endangered!

Almadraba technique

The Almadraba is a traditional form of tuna fishing using a a maze of netting fences. It is still used today in Portugal, Spain, Morocco, and Italy. In Sicily, the same method is called Tonnara.

Tuna in spring water

Canned tuna can be bought in brine, spring water, sunflower or olive oil. Tuna in water is higher in omega-3s and has fewer calories than tuna in oil. On the other hand, if canned in brine, the salt (sodium) content will be higher. From a nutrition standpoint, water-packed tuna provides you with pure protein and a more subtle tuna flavor.

Health benefits

Tuna is one of the best dietary sources of vitamin D. It also contains a high amount of omega-3 fatty acids that help reduce cholesterol and improve heart health. Among other health boosting benefits, tuna is rich in potassium, which can help lower blood pressure.

How much tuna is good for you?

While tuna is delicious and nutritious, too much of it can be detrimental to your health. Why?

Mercury exposure

In fact, mercury exposure is an important consideration when adding tuna to your diet. A single serving of some types of tuna may surpass the maximum amount of mercury that you can safely consume per week.

Limiting mercury consumption

Limiting mercury consumption is important to health, particularly for children and pregnant women.

Best choices for children

In the United States, the Environmental Protection Agency (EPA) and Food and Drug Administration (FDA) rank canned light tuna to be among the best choices for children to eat, recommending two to three servings a week.

Market leaders

THE WWF notes the majority of the market is made up of four species: skipjack alone account for more than half of the global catch of tuna, followed by yellowfin, bigeye, and albacore.

Aquaculture

In response to the worrying decline in fish stocks, increasing quantities of high-grade tuna caught at sea are reared in net pens and fed bait fish.

Farming vulnerable species

Meanwhile, farming of the vulnerable Atlantic bluefin is taking place in the Mediterranean, North America, and Japan.

Conservation efforts

While these conservation initiatives are to be applauded, research published in 2016 indicates that increasing ocean temperatures are taking a toll on tuna populations in the Indian Ocean. Rapid warming of the ocean has resulted in a reduction of marine phytoplankton, the main source of food for bigeye tuna.