However, microbe-based food is years away from being ready to supply large industries, and researchers still need to conduct taste tests to make sure there's nothing especially fishy about a salmon that's been dining on yeast.
Changing fish food will likely also help cut the carbon footprint of many fish farms. One of the biggest components of a Norwegian salmon farm's greenhouse-gas impact is associated with the transportation of food sources, so if microbial food is a success, it could lessen that impact.Other options for alternative fish food exist, too. A British business magnate has been creating protein meal made from housefly larvae, better known as maggots, and selling that to poultry and salmon farms in South Africa, as NPR reported.
There may also be ways to tweak fish to get more nutrition from them. Preliminary research has identified a genetic variant in rainbow trout that prompts them to make more omega-3 oils, a trait that could be exploited through traditional breeding techniques, USDA's Silverstein said. At the moment, “genetically improved” fish stocks make up just 10 percent of farmed fish in the U.S., Silverstein said. That figure could change soon. In December, the U.S. Food and Drug Administration released a preliminary finding that AquAdvantage salmon -- a genetically modified Atlantic salmon that grows to full size much faster than normal fish thanks to the addition of genes from Chinook salmon and the ocean pout -- would have “no significant impact” on the environment. That move signals that AquAdvantage salmon is nearing final approval.But AquAdvantage salmon has become a major flashpoint in the debate over genetically modified organisms. Last week, the FDA said it would extend the comment period on its environmental assessment of AquAdvantage salmon until late April.Improvements in fish-farm construction are also expected to boost aquaculture production.Catfish farmers have found success with split-pond designs. Such a design entails separating a smaller area, where the fish are kept, from a much larger area, where the water is treated. Split-pond farming has helped catfish farmers see their yields triple to 15,000 pounds per acre from 5,000 pounds per acre in the last several years, according to Silverstein.Land-based enclosures are also catching on in aquaculture. Right now, you might be perturbed at the thought of a salmon grown in the Midwest, but such a scenario could be in the future of sustainable fish farming.
Steven Summerfelt, who oversees research into sustainable aquaculture techniques at the Arlington, Va.-based nonprofit environmental group The Conservation Fund, said the latest contained fish farms use less water and pollute far less than farms in open oceans.“If done properly, there’s no discharge allowed,” Summerfelt said.A single 3,300-metric ton next-generation salmon farm could produce enough fish each week to fill up an entire schoolbus, top to bottom, side to side, Summerfelt said -- a rate that could satisfy 1 percent of U.S. salmon consumption.
Human population explosion and declining wild-fish stocks around the globe practically dictate that fish farming will be a necessity in the near future -- and if the next generation of aquaculture realizes its promise, it could ensure that seafood stays on the plate for generations to come.