[en] The energy requirements for open basins used for single cell protein production and fish farming, and the possibility of supplying this energy from waste heat, are discussed. Heating requirements for open aquaculture basins were determined for three types of climatic conditions found in Oregon. All potential means of heat loss from the basins were evaluated. The main mechanism of heat loss was the combined effects of evaporation and convection at the surface of the basin. For a 4 foot deep basin the thermal inertia would be great enough to allow the use of daily average weather data for the computation of energy requirements. For a costal site, with once through cooling, the heated condenser discharge water was not warm enough to maintain a basin at 85⁰ F at any time of the year. The water was warm enough to heat the 75⁰ F basin from mid-May through October. The design heating rates for the 75⁰ F and 85⁰ F basins are 6,300 and 9,200 Btu/ft²-day respectively. It was concluded that raceways in which fish are grown in the condenser cooling water would be the most economical arrangement for this area. For a Willamette Valley site, using a wet cooling tower, it was found that the heated condenser discharge water was warm enough to meet the heating requirements for both the 75⁰ F and 85⁰ F basins throughout the year. These basins could be beneficially used to grow fish or algae with no other source of energy needed. (U.S.)