The impact of large reservoirs on fish biodiversity and fisheries in China

摘要

The fish biodiversity in large reservoirs is influenced by the hydro-biological changes after impoundment and subsequent fisheries management, particularly stocking, as well as their interaction. The original fiver fish fauna determine the resulting reservoir fish fauna, but dominant populations usually change from riverine species to lacustrine. Anadromous and/or catadromous migratory species are likely to disappear. Potamodromous migratory species (upstream for spawning, downstream for feeding, or vice versa) are also likely disappear or become much less abundant. The artificial stocking of Chinese carp etc. is a common strategy adopted in reservoir fisheries management and affects the biodiversity significantly. Four large reservoirs are selected as representative of large-size reservoirs in China. The number of fish species in these reservoirs is 40-90. Unlike in smaller reservoirs, where the stocked species dominate, in large reservoirs the population primarily consists of wild, naturally recruited species. Such populations and their diversity are subjected to long-term dynamic processes associated with the aging of the reservoirs and human activity.