Message in a bottle


Myths and facts: The truth about tuna.




In the 1950’s tuna was mainly used in casseroles and on sandwiches with a yearly catch of 600 000 tons. Today that number has grown to 7 milion tons and some species of tuna have become gourmet. The massive rise in the consumption of tuna has given way to many problems regarding sea life, the ocean and health issues as we are consuming a top sea predator.

“The main issues with consuming tuna are to do with peoples health and the sustainability of the fish” says the head of National Geographics Ocean Initiative Valerie Craig. Thus it is difficult to choose which tuna to eat and purchase. Should it be white, light or Yellowfin, fresh frozen or canned – which is the best and safest to eat?

The first thing to know is that there are many species of tuna caught and available and they have all been influenced by the surge in popularity of tuna consumption, some however have been affected such that they have become nearly extinct.
How the fish is caught affects their sustainability, bottom trawl fishing may be devastating for that method uses a line nearly 80km long with 3000 hooks, that is dragged at a depth of 100-150m. The biggest fish swim at that depth but so do sea turtles who get caught in the line and often die before reaching the vessel. Thus it is important to figure out how the fish is caught to understand the affects of our consumption.

Here is a small guide to tuna and how to consume it:

Canned Tuna Varieties

Albacore (Also known as White)
Commonly found in cans and pouches, albacore is a premium variety and is the only tuna species that can be called white due to its white flesh. Because of the fish’s larger size, it tends to contain more mercury. Enjoy up to 6 oz. (one meal) of albacore tuna per week.

Skipjack (Also known as Light)
70% of the canned and pouched tuna is actually skipjack (with some small amount of yellowfin). Because the flesh is light in colour (but not white), skipjack is also known as light tuna. Skipjack is a relatively small tuna, and therefore has a lower level of mercury. Skipjack tuna is the most sustainable type of tuna.

Yellowfin is also known as light canned or pouched tuna, named for its pale pink flesh. Less commonly canned than skipjack and albacore, yellowfin has a slightly more pronounced flavor than albacore.

Tuna Steaks
Because tuna steaks generally contain higher levels of mercury than canned light tuna, you may eat up to 6 ounces of tuna steak per week.

Also known as ahi in Hawaii (and as ahi tuna on restaurant menus). Usually eaten as a steak or as sashimi, bigeye tuna is not typically canned.

Bluefin tuna is highly prized for its dark and fatty flesh. It is a delicacy in Japan, where the price of a single giant tuna can exceed $100,000. It is mostly made into sashimi, and not found in cans or pouches. However, because bluefin tuna is slow to reproduce and grossly over-fished, it has become the focus of vigorous conservation efforts by governments and regulatory agencies.