KUALA TERENGGANU: The damage is done. It is irreversible when foreign predatory fish populate most major rivers in the country.
The fear is that indigenous fish species, falling prey to these predators, may become extinct within five to 10 years. Experts are finding a way to remove the predators from the wild before they over-populate.
Universiti Malaysia Terengganu (UMT) ichthyologist Dr Amirrudin Ahmad said importing predatory species was harmless, as they were only fry at first.
“Aquarium fish traders may or may not be aware of the danger these predatory species pose. Hobbyists, too, may not have been informed of the fishes’ adult size.
“The aquaculture sector was looking for an alternative specimen and introduced the African catfish, which can grow up to an enormous size.”
Amirrudin is one of the people in charge of Malaysia’s native fish species and is responsible for the discovery of the world’s smallest fish, Paedocypris progenetica, in 2006.
He said based on information from anglers, the predatory species could have been in the rivers for a few years.
He said anglers shared the blame by releasing such fishes, like the peacock bass, into abandoned mining pools, although they might not be aware that it could wipe out local fish species.
Anglers have been reported catching varieties of the highly aggressive and predatory peacock bass, Chao Phraya high fin giant catfish, pirarucu, pacu, red tail catfish and alligator gar.
State Fisheries Department director Zawawi Ali said hobbyists generally dumped predatory fishes into rivers .
He said hobbyists would dispose of their collection into rivers when the fish could no longer fit into their tanks or when they stopped their hobby.
“Feeding big fishes is costly. This may also be the reason they have to dispose of their collection.”
Zawawi said a problem would arise when hobbyists imported predatory fish species without verifying with the department whether the species was banned.
He urged those who intended to dispose of their collection to inform the department so it could help them to do so.
He appealed to importers to refer to the department, which had a list of fishes that were banned.