In the waters of the Mekong, in Cambodia, a team of researchers assisted by local fishermen spotted, on June 14, the largest freshwater fish ever documented. It is a 300 kilo ray, measuring 4 meters long from the head to the end of the tail. The previous record belonged to a giant catfish weighing 293 kilos – a representative of an endangered species caught in 2005 in the same river, but in Thailand.
“It is almost inconceivable that a fish of such size is still present in a river as developed as the Mekong, where fishing is very popular”, is surprised in Science Zeb Hogan, a fish biologist at the University of Nevada at Reno. The scientist, member of an international collaboration called Wonders of the Mekong (“Wonders of the Mekong”), is part of an expedition that aims to fit some 200 fish with acoustic sensors and then release them into the river. The sensors make it possible to follow their movements in an area of 300 kilometers, with many meanders, in the north of the country. The data thus collected should contribute to the implementation of conservation measures.
Ecosystems in danger
“The project concerns a very upstream section of the river, which is home to almost 1,000 aquatic species and which is thought to be a very important refuge for freshwater fish during the dry season”, says the scientific journal to which Solomon David, an aquatic ecologist at Nicholls State University in Louisiana, who is not associated with the Wonders of the Mekong project, is delighted:
“The fact that we found such a rare specimen suggests that there is still time to preserve these gigantic freshwater fish.”
According to him, fresh waters, especially rivers, are among the most threatened ecosystems. But we must act quickly to conserve these unique habitats, he insists.