Comparison of nutrients release among some maricultured animals

Integrated mariculture is a feasible method to maintain sustainable and hig h productivity of aquaculture. The choice of cultured animals and biofilter s in the integrated system has to be made on the basis of their nutrient re lease rates and the clearance rate of each component of the system. We are examining the nutrient release rates among fish (mangrove snapper, Lutjanus russeli, and sea perch, Abudefduf septemfasciatus), abalone ( Haliotis div ersicolor), scallops (Chlamys noblis), and green mussels (Perna viridis) in the laboratory. Fish feed is the major sources of inorganic nutrient input in fish farms. The orthophosphate and ammonia release rates of minced tras h fish (1593 mug P g(-1) day(-1) and 150 mug N g(-1) day(-1)) were respecti vely 6-12 times and 4-88 times higher than those of cultivated fish. Mangro ve snapper had the overall highest nutrient release rate, followed by sea p erch, abalone, scallops, and mussels for nitrite and nitrate; and followed by abalone, sea perch, mussels, and scallops for orthophosphate and ammoniu m. Among mollusks, abalone had the highest orthophosphate (162 mug P g(-1) day(-1)), nitrate (1.4 mug N g(-1) day(-1)), nitrite (1.6 mug N g(-1) day(- 1)) and ammonium (25.0 mug N g(-1) day(-1)) release rates per gram wet weig ht per day. Abalone released large amounts of orthophosphate, nitrite and n itrate in the experiment. Scallops and green mussels had low nutrient relea se rates. (C) 2001 Elsevier Science B.V. All rights reserved.