All sturgeon fishing including catch-and-release will be prohibited in the mainstem Columbia River from The Dalles Dam to the Priest Rapids Dam starting Saturday through September 15.  Oregon and Washington fishery managers say the decision was made due to increased mortality among adult sturgeon attributed to warm water temperatures.  Approximately 24 adult sturgeon mortalities have been reported recently with most occurring in the John Day Pool.  High water temperatures and lower dissolved oxygen have been shown to stress and kill sturgeon.  While only catch-and-release fishing is allowed this time of year, closing all fishing will help reduce stress from capture and handling and give sturgeon some relief until water temperatures cool off in September.  While the lower and mid-Columbia River white sturgeon populations are not considered to be in danger, the population is not at desired abundance, especially in some of the reservoirs where recruitment of young fish is sporadic.  ODFW will continue to coordinate with other fish managers to monitor sturgeon mortality in the Bonneville, The Dalles, and John Day reservoirs.