Maryland Unveils Green Recirculating Aquaculture

The world’s oceans are running out of fish, and soon we’ll be beyond the point of no return – but human appetite for seafood isn’t going anywhere, writes Stephanie Rogers, Mother Nature Network. That stark fact has led to ambitious efforts to farm fish in an environmentally friendly way instead of relying upon the stock in the sea, including a new system called Recirculating Marine Aquaculture.

According to the Mother Nature Network report, this way of farming fish on land, developed by the University of Maryland Biotechnology Institute (UMBI) Center of Marine Biotechnology in Maryland, relies on artificial sea water that is filtered and recycled after use. Methane from fish waste is captured to offset some of the energy required to raise the fish in captivity. Some of the fish that have been raised using the Recirculating Marine Aquaculture method include European seabass, striped bass and blue crabs.

"Green fish, as good as it gets”, Yonathon Zohar, director of the Center of Marine Biotechnology at UMBI told the news organisation. “Clean, environmentally friendly, sushi-quality fish, delivered to the restaurant a few hours after harvesting."

The UN estimates that 75 to 80 percent of wild fish stocks are either already overfished or getting too close for comfort, and conventional methods of raising fish on land have their own problems. Aquaculture critics point out issues with water pollution from concentrated fish waste, as well as what is often seen as the unnecessary sacrifice of some types of fish to feed the farmed ones.

In addition to filtering and reusing the water used to raise the fish, UM researchers are developing new recipes for fish food made from plant material and algae instead of fish meal. Zohar also contends that higher water quality allows a greater concentration of fish per tank without disease or parasite problems, increasing yield.