Today on Species Tuesday, we’re going to break all of the rules and talk about MULTIPLE species. There are about 60 different species of tuna or “tuna-like fishes,” all of which fall under the taxonomic group Thunnini. Found throughout temperate and tropical waters, tuna can reach up to eight feet long and weigh about 1,500 pounds. But don’t think that these fish are just slow fatties (we’re looking at you, sunfish). Tuna are built for speed; with their streamline and muscular bodies, they can reach speeds of 45 mph. That’s underwater; early data out of SUFB’s finfish lab/Andrew’s basement suggests that tuna are much slower on land.
The World Wildlife Foundation says that “if fish were like cars, tuna would be the Ferraris of the ocean.” This comparison is unfortunately fitting, as tuna these days is becoming more and more of a luxury. It’s no secret that, throughout the world, tuna is an incredibly popular seafood item. According to the FAO, skipjack, yellowfin, bigeye, and albacore tuna comprised over 98% of the more than six million ton total tuna catch in 2010. While that may be great news for people who wanted to eat tuna in 2010, it’s pretty worrisome news for anyone who wants to eat tuna ever again. Due to the extremely high global demand for tuna fish, harvesting technology has gotten incredibly efficient. Management tactics, however, have lagged behind.
The IUCN lists yellowfin and albacore tuna as “near threatened,” bigeye as “vulnerable.” And if worldwide we decided to focus on implementing better conservation and management strategies for tuna species tomorrow, these species might have a bright future. If that’s not the case, though, then we might have to make some difficult choices. You see, while a lot of species we’ve talked about face pressure from humans in one way or another (overfishing or bycatch or pollution), tuna face ALL of those threats.
The market price of tuna, which is only going to go up the rarer they get, is fueling not only greater quotas for the legal fishery but also a large illegal fishery. Because juvenile tuna have been known to school with adult tuna of different species, gillnet tuna fishing can cause serious harm on future generations of other tuna species. And since tuna often consume small fish or squid, they’re at risk of accumulating large amounts of toxins like mercury.
This triple threat of pollution, overharvesting, and incidental bycatch puts tuna fish on an unfortunate path towards extinction, that is unless we’re able to do something about it. You can help ensure that future generations are around to enjoy these magnificent fish by limiting you tuna consumption to species that are not yet vulnerable to extinction (like skipjack) or those that have been caught sustainably (not with longlines). Not only will this broaden your pallet by exposing you to the wonderful world of tilapia, it will also show the tuna industry that sustainable management practices is a priority among its consumers.
Enjoy the Podcast!