Karakteristik Fisika dan Kimia Perairan di Laut Jawa – Ambang Dewakang

Abstract

Physical and Chemical Properties of Waters in Java – Ambang Dewakang Sea.The Java Sea is a region of important pelagic fish production in Indonesia. The distribution of abundance of fish is affected by changes in water physical and chemical properties. The important chemical property that can affect the abundance of the fish is the availability of nutrients. Nutrients are the basic compounds of marine biogeochemical cycles that play important role in increasing aquatic productivity through growth of the phytoplankton. The purposes of this study are to know recent condition of chemical and physical characteristics of the sea water within the region Java Sea ‒ Ambang Dewakang and to investigate relationships among these parameters. This research was conducted in November 2014 at 7 stations in the region. The observed parameters were physical (temperature, salinity, turbidity, density) and chemical such as nutrients (DIN, PO₄-P, SiO₃-Si), pH, and DO. CTD (Conductivity-Temperature-Depth) SBE (Sea Bird Electronics) 911 Plus was used to measure water physical properties. Water sample was collected using Rosette sampler, while analysis of nutrients concentration employed methods from Strickland and Parsons 1972. The result showed that temperatures in the Java Sea ranged from 13.06 – 30.33 °C with an average of 25.29 °C, whereas salinity ranged between 33.07 – 34.74 psu with an average of 34.41 psu. Variations within temperature and salinity showed a homogeneous condition due to the influence of mixing processes. Concentration range of DIN (NO₃-N+NO₂-N+NH₄-N), PO₄-P, SiO₃-Si were from 0.070 to 0.180 mg/L, from 0.004 to 0.022 mg/L and from 0.082 to 0.361 mg/L, with an average of 0.096 mg/L, 0.010 mg/L, and 0.159 mg/L respectively. The ratio DIN/DIP of 13.24 showed that the waters quality of Java Sea was in the moderate category.