‘Death spiral’: Mekong River megafish have shrunk by half, study reveals

Fish once as large as grizzly bears have become far smaller in recent years due to overfishing, dams and climate crisis

The size of megafish in the Mekong River has shrunk alarmingly in recent years owing to overfishing, a study has found. The length of the largest and most endangered freshwater giants, some as big as grizzly bears, decreased by 40% in seven years.

Some fish, like the Mekong giant catfish, have been studied for over a longer period and show a decline in weight of 55% in the past 25 years, dropping from an average of 180kg (397lb) to 80kg.