An oyster aquaculture system, designed to take advantage of excess phytoplankton production, was integrated with an intensive fish aquaculture system on a pilot scale. In addition to providing a commerical product from otherwise unutilized biomass, the oyster culture system functioned as a biological filter to remove excessive and dangerous levels of phytoplankton from the fish pond water. Oyster growth was rapid at ambient temperatures greater than or equal to 27°C, producing a commercial product within 14 to 18 months; phytoplankton levels were sufficiently reduced to allow a 50% reduction in fresh sea water input to the fish ponds. The reduction of nutrient levels in the runoff water is ecologically advantageous in a system proximal to delicate coral reefs.