Feeds of the Future: Developing Alternative Aquaculture Feeds
As simple as it looks, fish feeds are specially formulated to maintain healthy fish and convey the human health benefits of eating seafood.
Fish feeds comprise one of the most expensive inputs to aquaculture. At feeding time, fish are closely monitoring via underwater cameras to ensure that excess feeds does not drift to the seabed. (Credit: John Bielka)
Ewww! It might not look appetizing, but the parts of fish that are not processed into fillets provide essential nutrients like omega-3 fatty acids as part of fish food.
September 20, 2012
Aquaculture is the world’s fastest-growing form of food production and a vital component of our food supply. But the industry’s growing demand for fish feed, which is derived mainly from wild populations of smaller fish such as anchovies and sardines, will soon outstrip supply. Can we replace wild-caught fish in the diets of farmed fish so that the aquaculture industry’s continued growth will be sustainable? Researchers from NOAA and the US Department of Agriculture have been working on this problem and a report released this month, The Future of Aquafeeds, details their progress.
Fish not eating fish
Most of the finfish that people like to eat – such as tuna, salmon, and bass – feed on smaller fish and shellfish in the wild. Traditional aquaculture feeds are based on fishmeal and oils that mimic that natural diet. But it turns out that, when raised on a farm, carnivorous fish don’t need to eat fish.
According to Dr. Michael Rust, Aquaculture Research Program Manager at NOAA’s Northwest Fisheries Science Center, “All fish—carnivore, herbivore, and omnivore—require about 40 nutrients in the correct ratio. It doesn’t matter to the health of the fish where the nutrients come from. By incorporating marine algae, fish processing trimmings, and a variety of plant products, we can formulate high quality fish feeds without relying on wild-caught fish."
Scientists have been working to substitute ingredients in aquafeeds for years. But the NOAA-USDA Alternative Feeds Initiative has accelerated this progress by supporting federal scientists and their partners in academia and industry. “We are getting to the point,” says Rust, “that substituting for fishmeal and oil is an increasingly viable option.”
The need for alternatives
This option couldn’t come too soon, as the wild populations of small fish used to produce fish feed are subject to increasing demand from a variety of sources. One indication is the price of fishmeal, which has nearly tripled between 2002 and 2010. Ecological limits apply too. The forage fish used in fishmeal play an important role in marine ecosystems by supporting commercially valuable populations of wild fish such as tuna and swordfish, as well as marine mammals and other ocean life.
The challenge has been to develop economically-viable alternative aquafeeds that maintain the nutritional quality of farmed seafood. Fish are considered a “superfood” in part because they are rich in heart- and brain-healthy omega-3 fatty acids. These compounds will only reach the consumer’s plate if they are present in the feed used on fish farms.
Collaboration leads to results
The Future of Aquafeeds -- a collaboration among stakeholders from a variety of disciplines -- outlines key findings and recommendations and includes seven case studies that demonstrate how this can be accomplished. In one, researchers develop improved methods to process seaweeds, which are rich in omega-3 fatty acids, into fish feed. In another, researchers refine methods for handling fish processing byproducts, allowing for greater production of fishmeal and less waste.
“It might sound simple,” says Rust, “but these research achievements represent a huge step forward for aquaculture’s ability to meet the growing demand for seafood.” With the world market for aquaculture feeds growing at 6-8% per year, they also represent a significant opportunity for the U.S. feeds sector and its suppliers.