A Baltimore lab aims to take the science of growing clean, healthy salt-water fish to the global marketplace

The wood-grilled whole dorado, at $34, is the highest-priced dish on the current menu at Pazo, the casually elegant restaurant in Fells Point in Baltimore. Executive chef Mario Cano Catalan gushes about the restaurant's specimens of the high-value Mediterranean fish, whose market name is gilthead sea bream, a sparkling silver species with a band of yellowish gleam at its head.

The ones Catalan prepares weigh a pound or a little over, he says, and after scaling and gutting them, he seasons them with crushed oregano and sea salt.

"They are cooked slowly," Catalan explains, "at a medium temperature of about 400 degrees, and the juicy, moist...