Yes they can, they are farming a fish called Cobia in Queensland Australia that is a sashimi grade fish. The farming process is surprisingly good too, they worked with a local company and sorted out a crop based land grown food pellet for the fish to remove a large amount of reliance on pulling their food source from the ocean.

http://www.abc.net.au/news/2016-04-01/cobia-to-kick-start-mu...