KANDUNGAN LOGAM BERAT DAN PLANKTON PADA EKOSISTEM TAMBAK BERMANGROVE DAN TAMBAK TANPA MANGROVE (Kasus di Tegal Tangkil, Cikiong, Poponcol, dan Kedung Peluk)

Abstract

Research on the quality of fish pond in the mangrove and non-mangrove ecosystem has been conducted from July to December2011 at four research sites i.e: RPH Tegal Tangkil, RPH Cikiong, RPH Poponcol (under KPH Purwakarta-Karawang), and Kedung Peluk village Sidoarjo, East Java. The purpose of the study was to determine heavy metal content absorbed in mangrove, water, soil, and fish/shrimp speciment. Theresults indicated severe accumulation of Pb (lead), Cu (copper), and As (arsenic)that was found mostly on leaves (for Zn) and root (for Hg) of Avicenia marina (Forsk.) Vierh species. Accumulation of five contaminants (Cu, Hg, Pb, Zn, and As) was found on fish pond without mangrove vegetation. Highest content of Cu and Zn was found in RPH Tega Tangkil (650.33 ppm) and in Kedung Peluk, Sidoarjo (845.24 ppm) respectively. In general, water quality of fish pond with mangrove vegetation was better than pond without mangrove vegetation. This was indicated by its water chemical and physical properties. Detergent content on fish pond without mangrove vegetation in Kedung Peluk and Poponcol was higher than standard quality allowed for fish cultivation. Content of Pb contaminant on fish was 6.60 ppm orthree times higher than the maximum allowable level (two ppm). Pb content on shrim in the non-mangrove fish pond in RPH Tegal tangkil was 3.88 ppm. Zn accumulation on bandeng and mujair fish in Tegal Tangkil, Poponcol, and Kedung Peluk exceeded the maximum allowable level. Plankton diversity in the research site was considered under poor category as diversity index value (H ') is < 2. Uniformity index (E) of mangrove water in Tegal Tangkil and Kedung Peluk, Sidoarjo was relatively similar (0.175 and 0.172). Highest plankton dominance index was found in Tegal Tangkil 0.368.