3.4.2.1 Obstructional effects of dams on fisheries

3.4.2.1 Obstructional effects of dams on fisheries

If the riverine fishery is sustained by stocks of migrating fishes that become blocked by a dam, the riverine fishery can be severely impacted. If the migrating fishes are anadromous or catadromous species, linked to ocean fisheries, or those of inland seas or large lakes, the negative impacts to these stocks and their associated fisheries can be catastrophic. Major concern throughout Asia is that movements of migratory fishes along river courses will be blocked by dams. Additionally, dewatering of stream channels immediately downstream from dams can be a serious problem. Dams also can block the flow of nutrients from ocean environments upstream into riverine environments by preventing anadromous fishes that die after spawning (eg, Pacific Salmon) from depositing these nutrients via carcass decay in upstream reaches.

Last modified: Thursday, 17 November 2011, 7:11 AM