If we do nothing…
The future of tuna is largely uncertain. Many projections estimate that tuna may become extinct by the year 2050 if overfishing continues at current rates. Since tuna are an apex predator, residing in the highest trophic level, this would result in the collapse of the ocean’s food chain.
This is why we must find sustainable solutions for the long-term heath of tuna and our oceans. The obvious solutions of regulating an industry as large as the tuna industry and simply eating less fish will not be enough as the global population continues to grow. Below are potential sustainable solutions for tuna fishing.
THE POTENTIAL OF THE KONA KAMPACHI FISH
(source: Kampachi Farms)
The Kona Kampachi is the domesticated breed of the Almaco Jack or Kahala fish. It is native to Hawaii, where it is farmed with significantly less environmental impact than farmed tuna. These fish are hatched in off-shore fisheries and then transferred to the open ocean where they are raised in an aquapod.
How?
- This fish has one of the lowest feed-to-produced-fish ratios of all harvested fish, requiring only one pound of feed to produce between 1.6 and 2 pounds of Kona Kampachi.
- (Compare this ratio to that of tuna, which require 15 pounds of fish for every additional pound they gain on ranches to achieve the fatty texture that consumers want in their fish.)
- While farmed fish usually have a harsh impact on the environment due to fish waste polluting the surrounding waters, the strong Hawaiian currents disperse the fish waste so that it does not accumulate in one area. This greatly reduces pollution and dead zones around fish farms.
What is an aquapod?
Aquapods make off-shore aquaculture possible. Rather than keeping fish close to shore in pens, these cages float approximately three miles below the surface and are able to drift with the current from the end of a tether keeping it tied to the base.
(The aquapod floats freely with the current where strong currents give the fish a more natural habitat. The fish can swim freely within the structure and are fed a healthy diet from when they arrive as hatchlings until their harvest. The aquapod has proved to be efficient, with a 98% survival rate, while minimizing environmental impact and any obstruction of waterways.
REDESIGNING THE WAY WE FARM FISH
When TedX speaker Dan Barber describes the best fish he’s tasted in his life, one would not expect the reason to be that the fish was grown in a sustainable fishery. However, building more sustainable fisheries does not have to mean focusing only on the target fish; in fact, integrating the entire food web is essential in rebuilding and maintaining our diverse ecosystems. In terms of environmental sustainability and even taste, the most effective fish farm would be an ecosystem itself.
Eating lower on the food chain
Our demand for seafood needs to be redistributed more evenly throughout the food chain. Smaller fish require less food to grow to their full size, unlike tuna. Eating less of one species will keep the ecosystem more in balance while saving wild fish that are caught for the sole purpose of feeding larger farmed fish.
Shellfish, especially!
Shellfish are significantly lower in demand than predatory fish, like tuna, but they are essential to the ecosystem. Shellfish filter water, leaving the water cleaner after it has passed than before the current came through. Supporting a growing market for shellfish would enable more fisheries to pair polluting fish farms with purifying shellfish farms.
What would this look like?
The Veta La Palma fishery in Spain grows shrimp, which feed on the naturally-occuring algae in the waterway. Sea bass as well as other species of fish are able to thrive off the shrimp, and a flock of flamingoes feed on the fish and shrimp.
The presence of birds may seem disconcerting, but in fact their movement oxygenates the water, keeping the fish healthy, and the health of the birds also provides a good indicator as to how the fish are doing.
This water also leaves the fishery cleaner than it was before. The abundant shellfish filter the water as it flows through the fishery, which is beneficial to the environment as well as growing fish that taste better.
RESOURCES
http://www.kampachifarm.com/the-blue-horizon-imperative/
Greenberg, Paul. Four Fish: The Future of the Last Wild Food. Penguin Books, 2010.
http://www.aljazeera.com/programmes/earthrise/2012/04/20124615166529417.html
BIO
Anna Gaskill is a first year at Wellesley College. Her major is undecided, but she is interested in film and environmental science. She is on the crew team and enjoys listening to music and hiking.