Protein for a Growing World

    By 2050 the world’s population is predicted to rise to 9.3 billion. How can we provide enough protein for all of those hungry mouths? Animal agriculture requires arable land and fresh water, both of which are in short supply. Increased fishing doesn’t seem to be a viable option as wild fish populations are already plummeting. Can aquaculture help to fill the gap? Will it help us feed ourselves sustainably or will it drive wild fish species to extinction?

    Aquaculture and Pollution

    One of the main complaints about aquaculture is the water pollution often associated with conventional coastal fish farms. Fish waste and food scraps from these farms cloud the shallow waters, cause algal blooms and kill marine life beneath the pens. Innovative fish farmers and researchers are working on offshore alternatives to coastal pens. For instance, some producers are using enormous submerged cages anchored far enough offshore to allow strong currents to carry the waste out to the open ocean where it is diluted and consumed by plankton.

    Aquaculture and Fishmeal

    Many of the most popular aquaculture species are large predatory fish like tuna and salmon. These fish command high prices at market so it is easy to see why fish farmers have focused on them. With the collapse of wild tuna fisheries, it seems farm-raised tuna and salmon would be heralded as a sustainable substitute to endangered wild species. Farmed fish may not be wild fish but they eat wild fish, usually fishmeal made from anchovies and sardines. These small forage fish support the ocean’s food chain so overfishing of anchovies and sardines could decimate marine life as a whole.

    Aquaculture is growing at 7.5% per year. As production increases it will become ever more important to reduce or eliminate wild fish as a feed source. Progress has been made in recent decades. It was once common practice to feed whole sardines to aquaculture stocks. In many places this practice has been replaced with feeding formulated, aquaculture feed that is made up of fishmeal, soybean meal and other ingredients. Soybeans, and many other commodity crops are in short supply already, and they require a lot of land and water. If aquaculture is to lessen the pressure on land and water use then we need to minimize the amount of agricultural products that go into fish feed.

    Aquaculture and Algae

    Perhaps we need to look a little lower on the food chain than sardines and anchovies for fish food. Algae are at the very bottom of the marine food chain and the source of DHA, the omega-3 fatty acid that makes fish such a healthy food. Algae are already being produced as a source of DHA supplements for infant formula, milk and juice. Algae may help the aquaculture industry find true sustainability.

    Alltech's Algae Production is Growing [+]