Quality of Plankton and Physic-chemical Factors to Support Fisheries and Community Care in Babon River, Semarang, Central Java, Indonesia

Abstract

The research was conducted by observing the plankton biota, especially in the interaction and relationship between riverine biota and environmental factors. Plankton enable to provide an indication of environmental changes by determining the diversity (H’) and evenness (e) indices. Plankton sampling was carried out at 4 stations with different environmental conditions. Plankton were sampled using filtering method and analysed based on their diversity and evenness. Besides, analysis of its saprobic is also carried out to determine the level of pollution. The results showed that the most common species of planktons were Thallasiosera sp and Nitzchia spp. Thallasiosera dominates stagnant waters (dams) and prospect to support the growth of fish larvae. Other species which contribute to feed the fish larvae were Closterium. Diversity Index (H') shows that the status of the environment stability is in moderate condition, driven by temperature and speed of flow of the water. It is suggested that vegetative conservation on riverside area could reduce the temperature and speed of water flow and so providing more suitable habitat for biota therein.