The answer, Walsh contends, is more aquaculture. "Farming is unavoidable," he concludes.
No knowledgeable observer would disagree. Walsh artfully lays out many challenges that ramped-up aquaculture poses. He also points out that large-scale aquaculture, unlike crop farming and animal husbandry, is only a few decades old. For that reason, he cuts fish farmers some slack.
Perhaps too much slack. While acknowledging that most of the environmentally responsible aquaculture operations in existence today are smaller-scale operations, he (like many others) is mostly uncritical of genetically modifying seafood as a means to supplying more fish, even going so far as to label opponents "knee-jerk" in their resistance.
One approach to meeting demand, Walsh suggests, "is to take the fish we like and engineer them into sustainability." Really? Seems like a safer bet would be to take inherently sustainable fish species, such as perch and trout, and get more people to like them. Or to develop more mid-scale operations that, by their very size, minimize the risks of escapes and disease transfer.
The few large-scale operators that are positively rated by conservation organizations grow fish in land tanks that come with high energy inputs, an environmental cost generally not measured by marine scientists. Others are lauded for using grains rather than fish meal to feed their farmed creatures. That's good for the ocean's stock of healthy little fish, but not good when the fertilizers applied to grow the grains create dead zones in the ocean like the massive one in the Gulf of Mexico. Scaling up in concentrated locations has its problems.
Given that we've had real issues scaling up responsibly, why would we want to add another level of complexity and introduce genetically modified organisms (GMOs) into large-scale aquaculture? Where Walsh and many others stumble is in their general—if not wholly uncritical—acceptance of genetically modified fish as a way to feed a growing population. Thoughtful experts disagree about whether GMOs may have a role in the future of food, but it's foolhardy to hang the future of the world's seafood supply on an idea that has proven problematic with crops where they've had decades of testing.
Paul Greenberg recently offered a blunter observation of GMO fish farming in the context of the U.S. Environmental Protection Agency's pending decision to allow a gold mine in Bristol Bay, Alaska. Open pit mines near rivers have been notoriously bad for fish, the author of the award-winning Four Fish claims, citing the copper mine failure in China's Ting River that killed millions of fish. A similar disaster in Bristol Bay could destroy the same amount of salmon that the company responsible for genetically modified salmon hopes to produce.
"Instead of endorsing a risky experiment in genetic salmon modification, wouldn't it be better if our leaders protected wild salmon habitat?" Greenberg said on the public radio show Living on Earth. "In the end, we'd have just as much fish on our plates and a safer environment to boot."
