Assessment of the performance of Kappaphycus (Rhodophyta) cultivated in fish farm effluent
2006
Rodrigueza, M.R. | Montaño, M.N.E.
Intensive fish farming discharges large amounts of nutrients, the most of which is composed of dissolved nitrogen in the form of ammonium, which promotes eutrophication in coastal waters. Macroalgae have been proven to effectively reduce the nutrients of fish farm effluents and at the same time increase the economic output of the aquaculture system when economically important species are utilized. In this study, the potential of three carrageenophytes (Kappaphycus alvarezii, Kappaphycus sp., Kappaphycus striatum) of high commercial value to extract ammonia in fish farm effluent collected from a milkfish (Chanos chanos) fishcage was investigated. Also, the effect of elevated total ammonia of fish farm effluent on growth rate and phycocolloid yield and quality of these seaweeds was determined to establish the economic viability of the integrated culture system. The three carrageenophytes substantially reduced the ammonium content of the fish farm effluent (41-66% removal efficiency). Tank cultivation trials showed that the three carrageenophytes grew well in fish farm effluents, attaining maximum daily growth rate of 4.41%, 2.90% and 2.75% for K. striatum, Kappaphycus sp. and K. alvarezii, respectively. In terms of carrageenan production, all three Kappaphycus species improved although carrageenan quality, was not significantly enhanced when cultured in fish farms effluent. Elevated ammonium in fish farm did not adversely affect the performance of Kappaphycus, so that future integration of this seaweed in fish farms is feasible.
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