Fisheries officials have documented for the first time the migration of a river catfish from the Tonle Sap lake to the upper reaches of the Mekong river in Cambodia.
A 30-kg river catfish was caught Feb 8 near Stung Treng by a village fisherman, who contacted authorities after seeing a plastic marker attached to the fish that read: “Please return to the Department of Fisheries.”
The live fish was later returned to the Mekong river, said Nicolaas Van Zalinge, a fisheries biologist at the Mekong River Commission. Officials from the Department of Fisheries, the MRC and the World Wildlife Fund began catching and attaching ultrasonic transmitters to young river catfish in the Tonle Sap lake last October to research the locations of their spawning grounds, Van Zalinge said.
River catfish normally spend the dry season in deep water pools in the Mekong river before moving upriver to spawn. The river catfish caught in Stung Treng last month had previously been caught, tagged and released Nov 30 on the Tonle Sap lake by fisheries officials.
River catfish were the staple of the Cambodian fishing industry for years, accounting for 30 percent of fish production in the 1940s and 1950s. But the catfish population has plummeted due to overfishing and poor government management, said government fisheries specialist Touch Seang Tana. Catfish now account for just 3 percent of fishermen’s catches.