Not a drop of the water comes from the Inner Harbor, and not a drop gets into it, the marine scientist points out. The artificial sea water is recirculated after being filtered and treated to remove fish waste and excess food. By maintaining high water quality, he says, the tanks are able to hold denser concentrations of fish than the typical open-water fish farm but without the disease or parasite problems that can plague them.
The center also is developing and testing new recipes for fish food made from plant material and algae, instead of ground-up fish.
"These fish are as clean, green and organic as you can get," say Zohar, who has bred and raised striped bass and blue crabs in the Columbus Center laboratory. He's focusing the center's efforts on fish that he believes have commercial potential, such as branzini, a popular European fish that is farmed extensively in the Mediterranean to protect what remains of the wild stock. But Zohar notes that he's raised daurade, or sea bream, another Mediterranean fish, and recently began working with cobia, a popular sport fish also prized for its flavor. Staff members are preparing to try bluefin tuna in larger tanks.
Shawn Martin of Martin Seafood Co. in Jessup says he thinks there might be an opening for someone to produce a popular restaurant fish like branzini, which are now flown in from Europe and sell wholesale for $5.50 to $6 a pound. And if they can be branded as sustainable, they could command a premium price, Martin says.
"There's a big swing toward seafood sustainability," Martin says, "and there have been quite a few restaurants trying to serve only fish products that are sustainable. ... It's become a new niche market."
It's a tough business, though, for an entrepreneur to break into, notes Doug Lipton, a fisheries economist at the University of Maryland, College Park.
"The prospects are there. The technology is fascinating," he said, but relatively few finfish aquaculture operations in the United States have been able to attract investors because of the vagaries of the global seafood market.
But Casson Trenor of Greenpeace says Zohar could be onto something. The environmental group's seafood sustainability campaigner says a closed-loop fish operation like the UM center's could ease harvest pressure on the world's wild fish stocks without generating the environmental problems that crop up in open-water fish farming.
