I think the Conservationists were a day late/dollar short on this. First and foremost, this would be a food item to the locals. The fact that it got weighed at all I think is due to the research that was being done in the area, otherwise we may never have heard of this record.
Some diging found a recent article on a Cambodian website that said Giant Catfish were released into the Mekong River to try to boost species numbers which are thought to be on the edge of extinction. The once bountifull fish that has been persued in this area of Aisa for thousands of years, recently has become the victim of the same plight as many other species worldwide, ie, Dams, Polution, River navigation issues and Overfishing.
This release is under the watchfull eye of the World Wildlife Fund and country director Seng Teak. The release of 4 catfish happend last month (June/05) The Catfish were raise in captivity and taged to warn fisherman to release them should they get caught.