Malaysian anglers target invaders threatening native freshwater species

They use ‘slingshot fishing’ to save country’s rivers from ecological distress

- Muzliza Mustafa Malaysia Correspondent

With a slingshot in one hand and a fishing reel in the other, freshwater fisherman Muhamad Nasrullah Maludin waited on a bridge over a river in Sentul, Kuala Lumpur.

“See that black shape breaking the surface? That’s ikan bandaraya,” Mr Nasrullah told The Straits Times, using the local moniker for the pleco fish that compares it toa city council’s refuse collector, due to its habit of cleaning up algae and leftover food in aquariums.

Snapping into action, he released his slingshot and snagged one of the armoured invaders, then happily flung it into a gunny sack for later disposal.

Invasive species like pleco and African catfish have spread to 39 locations, including major rivers, dams and reservoirs, across Peninsular Malaysia and Labuan in Sabah, prompting warnings from fisheries officials that native fish populations face extinction.

Now, avid anglers like Mr Nasrullah are taking matters into their own hands, turning recreational fishing into an environmental rescue mission to save the country’s rivers from ecological distress.

Malaysia’s Department of Fisheries, which has been tracking the spread of fast-breeding invasive species through nationwide surveys since 2021, has warned that native fish such as lampam (tinfoil barb) and tengas (copper mahseer) risk disappearing.

Meanwhile, conservationists warn that invasive species like pleco are driving native fish towards extinction and raising flood risks by destabilising riverbanks. Other unwelcome species include peacock bass, alligator gar and redtail catfish.

Dr Nur Azalina Suzianti Feisal, who studies invasive species at the Management & Science University in Selangor, called plecos “riverbank destroyers”.

“The constant digging makes our river water permanently muddy,” she said. “Just like plants on land, underwater plants need sunlight to survive. The cloudy water blocks the sun, causing these plants to die”