Study of organic content and grain size sediment that affect water quality in the coastal area adjacent IMTA cages of Menjangan Besar Island, Karimunjawa, Jepara

The biotic and abiotic parameters of the waters influence each other so that the life of marine biota is greatly supported by the good quality of the aquatic environment. The purpose of this research is to determine the water quality based on physicochemical parameters in the IMTA (Integrated Multi Trophic Aquaculture) cultivation area compared to the reference area which is ±1 km away on Menjangan Besar Island. The samples were taken in May and December 2019 and taken in two different locations, IMTA and the reference area. Physical and chemical parameters such as temperature, pH, salinity and DO (Dissolved Oxygen), the grain size of the substrate and the content of organic matter C-organic, N-total and phosphate. Based on KEPMEN-LH No. 51 of 2004, the parameters that exceed the threshold are temperature, DO, phosphate and pH, salinity, substrate grain size, C-organic, and N-total values are still below the threshold that supports the life of marine biota. Varied results of physicochemical parameters are influenced by seasons, household waste, and cultivation activities