Nutrient waste removal efficiency of Seaweed Kappaphycus alvarezii by vertically method under different feeding rates in Integrated Multi-Trophic Aquaculture System Heriansah(a*), Radjuddin Syamsuddin(b) Najamuddin(b), Syafiuddin(b)
a) Institute of Maritime Technology and Business, Balik Diwa, Makassar, Indonesia
* heriansah.itbm.bd[at]gmail.com
b) Faculty of Marine Science and Fisheries, Hasanuddin University, Makassar, Indonesia
Abstract
A study of three feeding rates (5%, 7.5%, and 10% day-1) for rabbit fish, Siganus guttatus) was tried in a multitropic aquacuture method with a closed water recirculation system in laboratory scale involving green mussels Perna viridis, sea urchins Diadema cytosum , and Kappaphycus alvarezii seaweed. aims to determine the ability of seaweed K. alvarezii in reducing the concentrations of ammonium (NH4-), nitrate (NO3-), and orthophosphate (PO4-) produced from feed waste released at each feeding rate that was dissolved in the seaweed water culture media. During the 90 day experiment the capacity of K. alvarezii cultivated by the vertical method reduced the concentration of nitrogen and phosphorus compounds was quite good, showing that this algae was effectively utilized in the management of fish feed waste in a multitrophic aquaculture system. The concentrations of ammonium (NH4-N), nitrate (NO3-N), and orthophosphate (PO4-P), reduced in the culture media of K. alvarezii at feeding rates of 5%, 7.5%, and 10% were 84.28-89.12% ammonium, 86.88-89.07% nitrate, 98.31- 98.74% phosphate- 82.70-90.69% ammonium, 87.19-92.50% nitrate dan 98.12-99.23% phosphate- and 87.85-92.25% ammonium, 99.31-99.23% nitrate , and 98.71-99.86% phosphates, respectively
