Patagonian paradise lost? – The environmental hazards of farming fish in a warming world

A devastating report of the enormous environmental damage, and repeated massive salmon mortalities, in the farmed salmon industry in Chile. These impacts are many and varied: escaped fish prey on native species, and compete with native fish for food. Pesticides, antibiotics, and other chemicals given to fish or applied on farms work their way into the ecosystem. Plagues of sea lice proliferate in densely populated pens and can spread to wild salmon. Farming infrastructure along the coasts steals habitat from marine mammals. Fish faeces, uneaten food, and other biological wastes accumulate on the ocean floor, smothering marine plants and animals.

Then there is the environmental footprint of producing mass quantities of fish food—a mix of oil and meal from wild-caught fish, animal by-products, and soy—and transporting food, equipment, and fish to and from remote areas. When you add it all up, farmed salmon has a larger carbon footprint per pound than chicken.

The amount of nitrogen released by Chilean salmon farms every day is comparable to the waste of 9 million people.

Read Jessica McKenzie's full report in the Bulletin of the Atomic Scientists, 21 June 2023.