When we talk about seafood consumption, there is a product we can find at our disposal at any time; tuna. We can find it under different brands and in various categories.

In the markets, we usually find tuna in flat and round tins, often preserved in sunflower oil. But when we look at the world in general, tuna is much more than a piece of white and delicious meat squeezed into a tiny can. Today, we will discuss the journey of tuna from the sea to our plate.

Tuna is the general name for a group within the Scrombridae family, found in a subfamily called Scrombrinae. This group includes Mackerels, Spanish Mackerels, Bonitos, and of course, Tunas. Some fish in this family have names that represent the entire group after gaining economic value in the history of fishing, like Mackerel or Tuna, as I use in the title of this podcast. The Mackerel family is extensive, and it includes important fish species in each subfamily.

For example, Mackerel, which is widely sold as sorted, cleaned, and frozen in Turkiye, and Bonito fish, which holds high economic value in industrial or amateur fishing and they are in the same family. When you look on a Bonito and a Tuna, you will see that their body shapes are close and similar to each other.

How many types of tuna are there in the sea, and where do they live?

Tuna is a saltwater fish living in the light zone of the water where sunlight come into. Therefore, we can define tuna as a pelagic fish. Some experts of different professions like medical doctors or dietitians, may mistakenly define tuna as a bottom fish, but tuna is not benthic. Understanding this is crucial to comprehend the nutrition, survival, and reproduction of these fish.

Tuna fish is distributed worldwide, with varieties such as Bluefin, Yellowfin, Bigeye, Longfin, Slender and Albacore; they found in the Atlantic and the Pacific. These fish are trying to survive in various parts of the world. However, the future of tuna is in danger due to the fishing pressure on it. Although conservation activities are ongoing, we need to take steps to protect tuna, as we do for other aspects of our oceans.

How is tuna obtained? Is it being raised?

Traditional tuna supply is primarily obtained through fishing, but especially Albacore tuna is a fish that is cultured and growed up. There are notable companies involved in the tuna business along the shores of the Aegean Sea.

According to data from a 2021 report by FAO, which provides statistical data, tuna aquaculture figures are increasing significantly. In 2021, global tuna production reached approximately 7.3 million tons, a substantial increase from the 4.4 million tons produced in 2020.

The leading countries in tuna farming are China, Peru, Indonesia, Vietnam, and Mexico, making up 60% of global production. Tuna fishing is also notable, with 4.7M tons caught in 2021, compared to 4.2M tons in 2010. Countries like Japan, Taiwan, China, Peru, Spain, and the United States are prominent in tuna hunting.

Many tuna species are at risk, with Bluefin and Longfin tuna listed on the red list of the International Union for Conservation of Nature - IUCN. Protective measures are vital to sustainably harvest tuna from the sea, including hunting restrictions, quotas, and protected areas. You can find more information about the current situation regarding tuna in the 2021 fishing statistics report.

How is tuna processed and prepared?

We usually encounter tuna in vegetable oil in flat tins, but tuna offers more than that. Fish can be processed in various ways on ships equipped with advanced technologies for processing fish without bringing them to land. Alternatively, after removing the internal organs, fish can be stored in cold storage or on ice, which is the traditional method of fish preservation.

This is a common method used for nearly all fish. Alternatively, fish may be brought ashore and processed, often through freezing. When processing on the ship, fish is fileted, salted, and oiled before being canned. You can learn more about the canning process by watching instructional videos.

Canned tuna comes in various qualities. Some are in whole pieces, while others are more fragmented. The lower-priced varieties consist entirely of smaller pieces. It's important to pay attention to labels to understand the type of fish contained in the can.

Why the prices of the tuna fish is so different?

You might wonder why the prices of canned tuna from the same producer vary. This difference relates to the source of the fish and how it's processed. The same producer or importer may offer products from different parts of the fish to cater to various budgets. The nutritional content of these products may appear similar, but differences can include the weight of the packaging and the amount of oil in the can. Thus, I recommend becoming proficient in reading product labels.

Another form of tuna found in the market is packaged in sachets, offering low-fat, juicy meat. This product contains relatively less fat compared to canned varieties. The fish is filleted, salted, oiled to some extent, and then cooked with water in airtight bags. The product is packaged with this cooking liquid and put up for sale. In terms of healthiness, choosing tuna in water is recommended over canned varieties due to the salt and oil added during canning, as experts often suggest tuna for a healthier lifestyle.

Maguro

In addition to canned and cooked tuna, there is another popular consumption form of tuna in the Far East, known as Maguro. Maguro is a type of sushi and is highly popular in countries such as Japan, where seafood is consumed with great affection. Maguro means tuna meat. The best Maguro displays colors ranging from red to pink, though there are white varieties as well. The color of the meat is influenced by its fat content. Fattier Maguro is darker and redder, while leaner cuts appear lighter. Maguro can be prepared through grilling, steaming, frying, or even enjoyed raw. However, when consuming raw fish, it's essential to trust the source and quality of the meat.

Is it safe to eat tuna, or is it dangerous due to heavy metals?

Tuna consumption has raised concerns among professionals in fields beyond fishing. Recently, a dietitian responded to a question about consuming tuna on her Instagram stories, suggesting that tuna is a bottom-feeding fish and that she does not recommend its consumption. Furthermore, she highlighted concerns about heavy metal content.

Understanding the type of fish and its source is crucial when addressing these concerns.