Relationship Between N/P Ratio And Silicate Concentration Of Tambelan And Serasan Islands Waters

Abstract

As part of the Natuna Sea, Tambelan and Serasan Islands waters have a great potential of fishery. This potency can be decreased if not supported by suitable nutrient conditions for the growth of diatoms, because diatoms are part of marine food webs that support the abundance of comercially valuable fish. Some of those conditions are sufficient silicate concentration and nitrogen/ phosphorous (N/P) ratio that close to Redfield ratio that is 16, because at this ratio diatoms would effectively consume silicate thus can grow and develop well and can dominate the waters. A research on the relationship between the molar ratio of N/P and the distribution of silicate concentrations was conducted in the waters around Tambelan and Serasan Islands in November 2010 to investigate wether the condition of nutrients in these waters support the growth of diatoms. The results show that the N/P ratio range between 11.2 -133.7 while silicate concentrations range between 2.03 -4.80 μM and tend to be low when the N/P ratio close to 16. This is likely due to high and effective silicate uptake by diatom. These results coupled with the data of silicate average concentration that is 3.66 μM describe the good level of nutrients in the waters of Tambelan and Serasan Islands in supporting the growth of diatoms, seen from the abundance of diatom in which chaetoceros dominated the phytoplankton population in the waters of Tambelan Islands by 39% and in the waters of Serasan Islands by 37%.