Evaluasi Praktek Budidaya Sistem Keramba Jaring Apung Bertingkat Berdasarkan Taksa Dominan dan Oportunistik Makrobenthos
Sapto P. Putro, Riche Hariyati, Suhartana dan Agung Sudaryono 2013

Abstract
Environmental degradation resulting in decreased quantity of farmed fish production is a problem that often arises in A rapid industrial fisheries to meet the needs for food, especially seafood. Mass death in the cultivation period is often the case, especially in fish impoundment and floating net cage farm system. Based on this, the effective and efficient assessment of environmental quality are needed to increase production capacity and sustainability of its business. The purpose of this study was to assess the quality of environment at farming area as an evaluation of the practice of floating net cage farm system based on the dominant and opportunistic taxa of the macrobenthic structure. The research was carried out at location of floating net cage farms at Lake Rawa Pening, Semarang regency. Abiotic and biotic sampling performed every three months over the study period, each consisting of four stations with three replications. Sampling was also done in the same amount of area within 1 km of the area of farming as a reference. Determination of causal factors, the level of disturbance, and species/taxa as indicators were done by analyzing the data and their abundance and environmental parameters using multivariate analysis approach on the structure and composition of the macrobethos. The results indicate an environmental disturbance based on a change in the structure of the makrobenthos. Dominant and opportunistic taxa were able effectively to describe the level of disturbance caused by farming practice using multivariate approach. The results of this research implies that moving the ordinate of floating net cages is needed at least once a year to allow the environmental sediments are recovered from the disturbance, especially caused by organic enrichment.