In December 2016, The United Nations General Assembly declared World Tuna Day as an internationally recognized event in order to underline the significance of the conservation management and the socio-economic gravity of the eponymous fish. As tuna is one of the most extensively consumed fish—with more than four million tons fished annually—overfishing has pushed many species to the brink of extinction[i].
It is important to know which type of tuna you are putting on your plate, as many on the market have become unsustainable as a result of unethical fishing methods. And while there are many species that may appear at any fishery, here are the major ones that make up most of the tuna market.
So which tuna can you eat, and which should you avoid?
While the Southern bluefin is currently the only species labelled critically endangered by the International Union for Conservation of Nature, the general rule of thumb is to avoid all bluefins, as they are all overfished and vulnerable to becoming endangered. In fact, Pacific bluefins are at a mere 4% of historic population levels. Luckily, if you’re eating any bluefin tuna—sometimes labelled “o-toro”—you would know, as it is known to be pricey in comparison.
Albacore tuna is known for its white pale flesh, and is commonly sold as white tuna in cans. Despite being overfished in certain areas, albacore tuna is really the only option if you’re looking to get your tuna craving. This species can be caught with pole-and-line methods, which are considered much more ocean-friendly. BC albacore, in particular, is considered sustainable since the fish are troll caught with barbless hooks, helping eliminate bycatch of other species.
Bigeye is sometimes referred to as ‘ahi tuna’ along with the yellowfin. Unfortunately, bigeye is considered overfished in many regions of the world, and the most common fishing method of bigeye is using purse-seine nets, which causes collateral damage to countless other species like turtles, dolphins, and sharks—and other tuna species.
Yellowfin, the other ‘ahi’ is definitely on the avoid list, as the majority of this species is caught before they even get a chance to breed, further damaging the population levels. Purse seines and longlining are two of the main methods of fishing yellowfin, both of which are largely responsible for unwanted bycatch of other species: seabirds, turtles, swordfish–seriously, anything, you name it!
Skipjack is the most extensively fished of all tuna species and makes up for 70% of the canned tuna market in the United States, where it is often referred to as chunk light in cans. Although skipjack is the most abundant and fecund of all tuna species, the more serious issue is, unsurprisingly, its fishing method, as it is also mostly caught using large purse-seine nets. This is particularly problematic with skipjacks because they often swim with yellowfins and bigeyes, both of which are highly overfished.
The fishing method and location matter, a lot!
When buying tuna at a restaurant or a store, be sure to inquire about the source and fishing method. Location can be crucial; for example, Atlantic and Southern Pacific albacore tunas are experiencing overfishing, but North Pacific albacore tuna is not. When it comes to fishing methods, pole-and-line and trolling are considered sustainable and clean ways of fishing. Purse-seining and pelagic longlining come with tremendous collateral damage—this includes tens of millions of sharks every year.
To make matters worse, a study in 2016, “Emissions and Climate Forcing from Global and Arctic Fishing VesselsOpens a New Window.[ii]”, published in the Journal of Geophysical Research: Atmospheres, revealed that emissions from boats fishing for large species such as tuna warm the planet as much as producing pork, pound for pound[iii].
For more information on sustainable fishing, visit www.oceanwise.ca for more details on best fishing practices and sustainable seafood species to eat.
Tuna Products at SPUD
At SPUD, we sell canned albacore tuna from Raincoast Trading, which ranks number one on Greenpeace’s Canned Tuna Sustainability Ranking in Canada[iv]. Our seafood is either Ocean-Wise-approved or sourced from fisheries with sustainable practices, which means you don’t have to worry when ordering seafood from us.
There’s no doubt that sustainable seafood plays a crucial role for the future of the fishing industry. Before you make a purchase, consider the animal’s role in the ecosystem, find out how it got to your plate, and be mindful of the quantity consumed. Check out David Suzuki’s Top 10 sustainable seafood list for ocean-friendly seafood![i] https://www.theguardian.com/environment/2007/jan/22/japan.conservationandendangeredspecies