The effect of anthrophogenic changes on the sustainability of eastern sumatran floodplain fisheries resources

Abstract

Every human (anthrophogenic) activity along a river system has potential to influence on quantity and quality of aquatic environment and its organisms. Few studies have been conducted to evaluate the effect of these activities on fisheries resources. This paper examines the effect of anthropogenic changes on floodplain ecosystem of Eastern Sumatran fisheries. Fisheries data presented in this paper are derived from a desk study and multi-year field surveys conducted in three provinces; these were Giam Siak Kecil (GSK), Riau Province, and Batanghari River, Jambi Province (2010 to 2016) and Lempuing River, South Sumatra Province (2011-2013, 2016). In GSK, the results showed that there was a tendency for fish size to decrease along the river with decreasing riparian forest and increasing fishing intensity. In the Lempuing floodplain, fisheries degradation had occurred as a result of human activities such as conversion of land area for plantation, unpredictable flood pulses due to the Perjaya irrigation dam, high fishing intensity, and the use of un-friendly fishing gear. The number of fish species, here, decreased dramatically from 90 species in 1981 to 32 fish species in 2011, a decrease of 60% over three decades. In addition, total fish production decreased from 60 tonnes per year before 1996 to 12 tonnes per year in 2012, while the number of uneconomical and small sized fish caught increased. Decreases in fish diversity, size and catch rate were found in Jambi. Fish composition was dominated by small size blackfish (snakehead, climbing perch and Asian redtail catfish). Anthrophogenic activities contributed significantly to the degradation of floodplain fisheries resources, especially in relation to a decrease in forest cover due to fires that occurred between 1996 an 2000. An integrated management plan should be considered in the long term to support the Sustainable Development Goals for floodplain fisheries.