California Sea Grant College Program

For American aquaculture to prosper, farmers need access to technologies that can lower the costs of raising fish to marketable size. Water, energy and feed costs are all examples of expenses that today significantly constrain where and which species are reared. The viability of a business like Kent SeaTech, a large hybrid striped sea bass farm east of San Diego, is greatly enhanced by its ability to use geothermally heated water to grow its fish. As with many species, sea bass grow faster in warmer water. Even with this boon, however, the farm must constantly optimize how fish are distributed among its 97 tanks to maximize feed-conversion rates, minimize losses from disease, and maintain a steady supply of harvestable fish. This requires inventorying tanks regularly--a very labor-intensive process. It takes an eight-man crew two full days to net and weigh sub-samples of fish in each tank so that each tank’s biomass can be estimated—the key statistic needed for calculating feed-conversation rates. To effectively control feeding rates, the farm inventories its tanks monthly.