You are what fish eat
“Eat your fish,” we’re advised, “it’s good for you!”
And people responded, “OK!” — driving growth of an aquaculture industry that now provides half the seafood consumed globally. Until recently, the food those farmed fish ate was composed mostly of fishmeal and fish oil derived from wild fish, which imparted the health-promoting fatty acids EPA and DHA. But the industry’s rapid growth made using mainly wild-caught fish for feed unsustainable, so the industry began to adjust the content of feed to include more crop-based ingredients, such as corn and soy.
The shift to agriculture-based fish feed increases the environmental footprint of farm-raised seafood and may affect the health benefits of eating these fish, according to a study published earlier this month in the journal Environment International.
“Our review found that increasing plant-based ingredients can change the fatty acid content in farmed fish, which can affect human nutrition,” said Jillian Fry, director of the Center for a Livable Future’s Public Health and Sustainable Aquaculture Project at Johns Hopkins and the study’s lead author, in a press release.
The second issue is that fish food derived from plant-based crops may contribute to run-off and greenhouse gas emissions from land-based agriculture. To estimate the environmental impacts associated with the plant-based feed used for aquaculture, researchers from the University of Minnesota Institute on the Environment’s Global Landscapes Initiative quantified the land requirements to grow the feed and the amount of excess fertilizer in the landscape from producing it.
“Fish farming is the fastest growing sector of animal production. It reduces pressure on wild stocks, but it does have other environmental impacts,” said Paul West, GLI co-lead scientist. “Just like producing soy and corn to raise livestock, excess fertilizer and other consequences of farm management can impact our streams.”
Read the press release.
Photo by AlexRaths (iStock)