How to mitigate the problem of damn impoundment to Tor sp Dam impoundments create barriers across rivers that gives negatives impacts on natural fish populations. The dam impoundment can contribute to the disappearance and exticntion of species and also diminished abundance. Tor sp is one of species affected by dam impoundment. Mitigation measures are really need to prevent the problem from arise. A) Construction of fish passage There are three ways of fish migrations. First is upstream, second is downstream and last one is laterally. As Tor sp. is practices long distance migration, the dam impoundment would block their nature behavioural of migrating. Thus, fish passes can be the solution to the trapped fish in order to assist their migratory. However, there are several criteria that need to be followed in buiding the fish passes. It must provide passage for all fish sizes, whether large or small size,it have to be provided with …show more content…
Stocking is another alternative to the fish ladder. However, it was expensive and inefficient compared to fish passes technique. According to Agostinho et al. (2010), stocking is a method of managing fish populations which by releasing of cultivated or wild organisms to replenish a specific stock in order to increase the fishing yield by the natural recruitment. There are two divisions of stocking, that are maintenance stocking and the supplementation stocking. Maintenace stocking is the individuals of a species are released into an area where it historically naturally occur, but do not have self-sustaining populations anymore. While the supplement stocking is the natural stock that has demographic or genetic restrictions due to habitat modification, fragmentation, excessive fishing, and also recruitment failures. Stocking method provides the alternative means of subsistence and income, hence the pressure on the native stocks captured fishery can be