Healthy tuna and healthy oceans

Page - June 1, 2011
Overexploitation plagues our oceans. Species of all shapes and sizes are taken out and marine communities are devastated. Tuna are not immune: certain kinds of tuna are some of the hardest hit. Across our oceans, 90 per cent of large, predatory fish like tuna, cod and sharks have vanished.

The majority of tuna stocks are in decline. As fleets continue to fish them at a high rate, they will likely remain on this downward trajectory.

The fishing methods used to catch tuna also catch other fish and animals. Known as bycatch, this incidental capture of turtles, sharks, rays, seabirds, other interesting fish like trigger fish, and even dolphins, is common in longline fisheries and purse seine fisheries using Fish Aggregating Devices (FADs)- floating objects placed in the open ocean to attract fish then encircle them with huge nets.

FAD fishing is extremely wasteful. Every time a FAD is used, about 1kg of every 10kg catch will be unwanted sharks, rays, and various other species. When the ratio considers the bycatch of juvenile tuna, it is even higher. Globally, it is estimated that FAD-associated bycatch may now be as high as 182,500 tonnes annually. This global bycatch and wasted sea life would fill the equivalent of nearly 1 billion cans of tuna every year!

On average, longline vessels take on even more bycatch per trip than purse seiners with FADs. Up to 35 per cent of their catch by weight can be bycatch. Sea turtles and seabirds, some of which are endangered species, are particularly threatened by this fishing technique.

What about people who rely on the tuna for their livelihoods? They’re often tied up in unfair fishing agreements with little to no support for trying to protect the tuna’s future. Generally, they get a bunk deal.

There are ways to fish tuna without endangering other already vulnerable marine species or threatening the futures of tuna-rich coastal states. FAD-free purse seining, pole and line and trolling all minimize the impact on other species because they are more selective. Clover Leaf should support coastal state-owned fisheries employing these methods to help ensure tuna is ethically caught as well.