11 Sep 2011

Talking About Salmon Farms

At a potluck dinner this summer, I crowded into a kitchen with several other people. All of us are science fans who volunteer with Straitwatch. We help biologists gather data about how whale-watching affects the local orcas. Over dinner, we chatted about the Cohen Commission that is gathering information on salmon.
Salmon are a big issue here in British Columbia! We Straitwatch volunteers knew that most of what resident killer whales eat is salmon. Humans like these oily fishes, too, locally and around the world. "In the last two decades, global consumption of salmon has risen from 27,000 tons to more than 1 million tons annually," noted McKay Jenkins in his book What’s Gotten Into Us? Staying Healthy In A Toxic World. That's a lot of salmon. And much of the salmon we eat comes from fish farms. "So, what is it about farmed salmon anyway?" one of the volunteers asked. "What's different about it?" He wondered why anyone could complain to the Cohen Commission about fish farms. After all, fish farms supply a lot of food. People need food. If a million tons of wild salmon were harvested every year, there might not be any wild salmon left to spawn in some rivers.
Part of the difference, we explained, is that the farmed salmon doesn't taste the same as wild salmon. Wild fish grow up eating a lot of small sealife, especially tiny invertebrates that look like shrimp. That's why salmon flesh is a pink or red colour. Farmed salmon are fed ground-up fish made into pellets. Without their natural food, the flesh of farmed salmon is more pale and less firm than wild salmon.
The food pellets are very convenient for the fish farmers, but some people worry about what might be in the pellets. Pollution like heavy metals or industrial chemicals can build up in the food chain, affecting both fish and humans. "Farmed salmon turn out to have ‘significantly higher’ levels of flame retardants than wild fish, likely because they are fed ground-up fish that are themselves contaminated," McKay Jenkins observed.
Another difference that we science volunteers noticed here on the Pacific coast is that most of the farmed fish are Atlantic salmon, thousands of miles from the habitat where they evolved. These farmed salmon are raised in large nets, suspended in small ocean bays. The salmon in a farm don't have freedom to move about over a wide area and scatter their wastes. Under the farms, the muck piles up on the sea bottom.
"Salmon farms are dangerous to wild salmon," wrote marine biologist Alexandra
Morton on her website, "because they create a place where viruses, bacteria and parasites breed." Wild salmon migrating past the farms might get sick. The Coastal Alliance for Aquaculture Reform promotes on their website the idea of farming salmon and other fish in closed containers, instead of enclosure nets in narrow sea inlets along the salmon migration routes.
Biologists are taking samples, and bringing their findings to the Cohen Commission. But this Royal commission gets different reports from every expert who testifies! The Norwegian companies building the salmon farms say the germs are no problem. Clam harvesters near salmon farms claim that the clam beds are affected. It won't be easy for the best laws to be written to protect wild salmon as well as support sustainable business development.
At each city the commission visits, the public audiences get to see history being made. And as we science volunteers discussed the same issues, and some of us attended meetings of that commission, we were part of the ongoing public discussion. It's good to know that science isn't only used by specialists in a lab, but by people studying how to work and grow food in the wide world.

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