GRACILARIA-CHILENSIS OUTDOOR TANK CULTIVATION IN CHILE - USE OF LAND-BASED SALMON CULTURE EFFLUENTS

This study describes an integrated culture system developed for Gracil aria chilensis Bird, McLachlan & Oliveir a cultivation using salmon ta nk effluents, and tests the effects of algal stocking density, seawate r replacement rates and CO2 addition on biomass and agar production. E ffluents produced by intensive tank cultivation of salmon were an effe ctive source of seawater for the on-shore tank cultivation of Gracilar ia in southern Chile, giving production values of 48.9 kg(wet)/m(2) pe r year biomass yields were seasonal and agar yields were lower when fi sh effluent as wopposed to pure seawater was used. During the seasons of high growth, the agar content of Gracilaria was lower in the tanks receiving fish effluents. However, the Gracilaria biomass production w as sufficiently high to compensate for the lower agar content increasi ng agar production from 0.8 to 1.2 kg/m(2) by using fish effluents dur ing an 11-month period. These results were obtained without an extra s upply of nutrients or CO2 with an algal stocking density of 3 kg/m(2), and with 10 seawater replacements per day.