Disturbances and threats of Mekong River

Major developments on the Mekong which are likely to conflict with fisheries interests include various proposed irrigation projects, hydro-electric power projects, other industrial development and flood control projects. Dam construction and operation will change the hydrology of the river downstream, reducing seasonal flow peaks and minimizing access to floodplains for feeding and spawning. Changes in water quality and the timing of peak flows are likely to have adverse effects on fish migrations and spawning, and dams will create obvious problems for long distance longitudinal migrants.Impoundment will reduce sediment flow, particularly in the main channels, and thereby affect the nutrient regime downstream (Pantulu, 1986b).The water quality in the lower Mekong has been affected by domestic wastes and agricultural runoff carrying pesticides and fertilizers. Though localized at present, such problems are expected to increase.