The environmentalist case for fish farms

THIS SUMMER, tens of millions of salmon have been cooked in California in their own native habitat. Record-breaking heat and drought have drawn down the water flows and turned up the temperatures of the state’s streams and rivers. The heat shock, along with the impacts of parasites and fungal blights that are fueled by warmer waters, has decimated the wild salmon populations.

To stem the crisis, scientists have literally gone above and beyond, hurling salmon over dams via pneumatic cannons and  to the Pacific Ocean to bypass unlivable rivers. Meanwhile, with support from the Biden Administration, policy makers and water managers have diverted precious water resources from farms and cities to stem the salmon die-off. Even so, iconic salmon species such as Chinook could be wiped out along the US West Coast as drought persists.

The extreme preservation measures serve as glaring reminders that America urgently  to mitigate climate change. But the salmon crisis is sending another clear message: We need longer-term strategies of adaptation, including a significant expansion of aquaculture in the United States; federal lawmakers, investors, consumers and even environmentalists must all play a role.

While we expand fish farming, we should be extremely wary of creating an environmentally destructive feedlot industry in the ocean. Radical new advances in technologies and marine cultivation methods make it possible to correct existing problems so that aquaculture can grow sustainably.

§The growth potential is especially dramatic in the US, which imports 90% of its seafood — of which more than two thirds is farmed — yet it’s 17^th in the world in aquaculture production.

Here’s the caveat: For decades, aquaculture — and salmon farming in particular — has been a severe threat to wild fish and marine ecosystems rather than a necessary measure to protect them. Still today, salmon farming operations from Patagonia to Norway are plaguing pristine marine ecosystems with parasites, pollution, escaping fish and disease, while depleting wild fish populations like herring and sardines used as feed.

According to the UN, aquaculture could be the most sustainable method of protein production on earth if done right. Farmed salmon is the most environmentally intensive form of aquaculture — more resource-intensive than farmed tilapia, catfish and cod, for example — but salmon are frugal eaters compared to land animals. Fish generally need fewer calories because they’re cold-blooded and don’t have to heat their bodies or build layers of fat and fur for warmth. Nor do they need energy to resist gravity or walk upright on four legs. While it takes almost two pounds of feed to produce a pound of chicken, three for a pound of pork, and about seven for a pound of beef, it takes roughly one pound of feed to produce a pound of farmed salmon.

Because salmon farming is also the most profitable form of aquaculture — an $18 billion global industry that’s expected to nearly double by 2027 — technological advances in this field influence all other forms of fish farming. Where salmon farming goes, so goes aquaculture, is the industry adage.

In just the past decade, salmon farmers have cut in half the volume of wild fish used as feed and developed plant-based foods as alternatives; they’ve found ways to control parasites with robotic and laser technologies that can eliminate the use of insecticides; they’ve introduced closed containment systems that can capture waste and prohibit escapes. The most promising innovation is in fact thousands of years old — a practice known as “multi-tropic” aquaculture used by Chinese farmers circa 500 BC that cultivates diverse underwater farming habitats with multiple species — seaweed, bivalves, and finfish. It’s the marine equivalent of regenerative agriculture practices.

Investors need to support these innovations, and environmentalists need to update their argument against aquaculture rather than blocking its growth, pressuring producers to modernize their practices and calling on lawmakers to regulate the industry effectively.

In the US, the Magnuson-Stevens Fishery Conservation and Management Act has done an exceptional job of managing and restoring coastal fisheries and set an example worldwide. We need a policy this ambitious to guide the growth of aquaculture — requiring the highest standards for production and equipment as proposed by the Aquaculture Stewardship Council, Seafood Watch, and World Wildlife Fund.

Wild-caught seafood remains the dominant source of protein for nearly 4 billion people, mostly in the developing world. As climate pressures intensify, industrial nations must rapidly shift away from wild fish capture, protecting those resources for the populations that need them most. Aquaculture done right can help deacidify oceans and restore their health, supporting a climate-resilient food supply. America must take the lead in helping to ensure that a major expansion of aquaculture protects marine systems rather than destroys them.