Scientists at the U.S. Department of Agriculture’s Agricultural Research Service are trying to develop more sustainable fish feeds.
Instead of traditional fish feed that includes high levels of fishmeal and fish oil — which are impact stocks of smaller fish such as menhaden, herring and capelin — the fish feed the USDA is developing use plant proteins.
To produce the feed, the scientists use a piece of food-manufacturing equipment called a cooking extruder. Feeds for several fish including trout, salmon, white sea bass and yellowtail are being manufactured.
Six experimental diets containing combinations of alternative proteins, plus a fishmeal diet being used for comparison, are currently under evaluation at the ARS National Cold Water Marine Aquaculture Center in Franklin, Maine. According to the researchers, the studies indicate that the modern alternative diets work better for the fish than previous alternative diets.
Feeds for warmwater species, including pompano — one of Florida’s most valuable fish — are also being developed using ingredients like corn, gluten meal and soy proteins.
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