Giant catfish numbers in decline after 2016: official

MINISTRY of Environment spokesman Neth Pheaktra recently brought attention to the Mekong giant catfish and the giant Mekong barb, noting that regulations prohibiting fishing, trading or transporting the species have been in place since the Sangkum Reastr Niyum era of the 1950s.

“The Mekong giant catfish is on the International Union for Conservation of Nature (IUCN) Red List of Critical Endangered Species. It is also listed in Annex 1 of the CITES Convention, which strictly prohibits fishing, trading and other transportation,” he wrote in a social media post.

One of the three giant freshwater species present in the Kingdom – along with the giant freshwater stingray (Urogymnus polylepis) and the giant Mekong barb (Catlocarpio siamensis) – the giant catfish (Pangasianodon gigas) can grow up to 3m long and weigh up to 350kg, although few examples close to this size have been seen in recent years.

According to Thach Phanara, head of the Laboratory Division at the Inland Fisheries Research and Development Institute of the Fisheries Administration (FiA), each year from 1999 and 2016, the institution caught and released five to seven giant catfish along the Tonle Sap fishing trajectory. The released fish weighed from 80kg to 200kg and were up to 2.24m in length.

“Since 2016, their presence appears to have declined, and we see just one or two examples each year. Because these fish can be sold for extremely high prices in neighbouring countries, we believe local fisherman may be withholding information from our researchers,” he said.

Pheaktra explained that the Mekong giant catfish is the largest freshwater fish without scales. It is usually found in the Tonle Sap or upper Mekong rivers, although it migrates long distances.

It is often caught in stationary trawl fisheries in the Tonle Sap River as it returns from its spawning grounds in October, en route to lurk in the deeper waters of the upper Mekong.

They can live up to 60 years, and are one of the fastest-growing species of fish, gaining up to 10kg per year from their diet of aquatic plants and insects.

Unlike their catfish brethren, the Mekong giant barb is less elusive, with up to 10 per year being caught and released. A large scaled fish with distinctive dark red scales on its flanks, the largest recent example of a barb weighed 105kg, said Pheaktra.

“In 2005, by Royal Decree, the giant barb was made the national fish of Cambodia,” he added.

“This species is protected by Decree No 33 on the management of the fisheries sector in Chapter 2, Article 18. In ancient times, the scales of the giant barb were used to make shuttlecocks for traditional Khmer games. Images of this fish can be found carved on the towers of Angkor Wat,” he continued.

The research institute said that although the barb is present in greater numbers than the catfish, it is also a critically endangered species.