r
My girlfriend and I were at the supermarket recently and found ourselves in the aisle that had canned tuna. In my perpetual quest to save money, I normally purchase the chunk light tuna (the cheapest choice). But on this occasion, because we were shopping together, I asked my girlfriend which type she usually buys. She replied by expressing her inclination to “avoid the chunk light tuna because it is bad for the environment,” but admitted she wasn't exactly sure why that was. As we perused all the different ands and grades of canned tuna in front of us, we began to question what could possibly make them all so different. Clearly, we didn't know “skipjack” about tuna.
When I asked some friends about this later, most of them didn't have a clue, either. What's the difference between chunk light and albacore tuna? Is canned tuna something entirely different from those delicious, though somewhat pricey, tuna steaks served in fine-dining establishments or those artfully prepared morsels of sushi? Being an ecologist, this bewilderment is underscored further by a question I’m personally interested in knowing the answer to: Which, if any, of these different forms of tuna are environmentally sustainable? [The editors at What’s Up? Are eager to learn a thing or two about this, as well.]
As it turns out, there are many different species of tuna in the genus Thunnus, including those with familiar names like yellowfin, bluefin—also known as Atlantic or Northern bluefin—and albacore. Other tuna species (which, I admit, are less familiar to me) include bigeye and blackfin. One species often found in cans of chunk light tuna—skipjack—is actually in the genus Katsuwonis. Albacore, however, which is typically labeled “solid white,” is a true tuna.
While albacore makes a decent tuna steak, many “aficionados” would argue that its meat isn't nearly as good as some of the other true tunas, such as blackfin, yellowfin, bigeye, and bluefin. Of these, bluefin is considered the finest type of tuna meat. Many of its parts are considered delicacies and are widely used in sushi (it’s called “maguro” on sushi menus). Unfortunately, this distinction has resulted in overharvesting, which, in turn, has led to yellowfin, or ahi, tuna’s rising prominence as a sushi-grade fish.
The bluefin tuna actually has two other species—Pacific bluefin and Southern bluefin. The Southern bluefin is all but extinct due to a rapacious demand for tuna steaks and sushi, while the Pacific bluefin population is beginning to decline as well, due to overharvesting. Overall stocks are down significantly from historic highs.
The incredible price of bluefin tuna ($2,000–20,000 per fish) at auction doesn't give people much impetus to stop fishing for them. Japan purchases the largest portion of tuna, importing a half-million pounds every year. A few months ago, the Convention on International Trade of Endangered Species (CITES) proposed an international ban on bluefin tuna fishing to allow the stocks to recover. Blocking the motion, Japan cited too little evidence to support what they considered a drastic move. While a ban is extreme, Marylanders may remember a similar drastic measure back in the 1980s that revived the Chesapeake Bay's dwindling rockfish population.
So now that we're a bit more educated on the subject, the question is: Are there, in fact, sustainable tuna choices? The answer? Of course—but a little extra effort on the part of consumers is always required when we're faced with the reality that something we enjoy could very well become a pleasure of the past.
One of the best ways to start doing your part is to check out the Monterey Bay Aquarium's Seafood Watch program. The website has handy guides that can be printed out and tucked into in your wallet or purse, including guides geared to specific regions of the country—www.montereybayaquarium.org/cr/cr_seafoodwatch/download.aspx).
You'll find Maryland in the Southeast region guide, and in it you'll learn that the recommended options for tuna lovers around here are albacore and skipjack, caught by pole or trolling. Those considered “acceptable” are bigeye and yellowfin, again caught by pole or trolling. Avoid longline-caught fish of any species, including bluefin tuna. Longlining results in a lot of “by-catch” (sea turtles, for example, and other unintended catches).
Not sure about the type of tuna so deliciously described on that restaurant menu? All you need to do is ask your server—it's becoming commonplace for waitstaff to be well-informed about their workplaces' offerings, such as where a particular fish on the menu came from and the method by which it was caught. If your server is unsure, have him or her ask the chef. Being a responsible tuna lover will ensure our enjoyment of this tasty fish for years to come.
r
