Malaysia: Alien fish running riot in local rivers

ROSLI ZAKARIA New Straits Times 17 Apr 17;

KUALA TERENGGANU: PIRANHAS, African catfish, garfish, pirarucu, peacock bass, Chao Phraya high fin giant catfish and tilapia: these are all food fish in their countries of origin and are found in abundance in rivers, lakes and swamps, or bred in ponds in aquaculture projects.

Most of these fish species thrive in rivers and lakes many times bigger and deeper than the longest river in Malaysia.

In their natural environment, these fishes grow to monstrous sizes.

“All the fish mentioned above are carnivorous and predatory, including the tilapia which is an invasive species.

“Any minnow or fish that fits in their mouths will become prey and their voracious appetite helps them to grow to enormous sizes,” said Universiti Malaysia Terengganu (UMT) ichthyologist Dr Amirrudin Ahmad. These fish are native to the Amazon river (6,992km-long), Nile (6,893km), Congo (4,700km) and Mekong (4,350km).

In comparison, Malaysia’s longest river, Sungai Rajang, is just 563km long, while Sungai Kinabatangan is 560km and Sungai Pahang, 459km.

“The short span and narrow width of our rivers make it easy for predatory fishes to hunt for smaller fish like lampam, kelah, sebarau, kaloi, snakeheads (haruan, toman and bujuk), as well as the smaller Malaysian Clarias species (catfish),” said Amirrudin.

He said with the existence of these predatory fishes in local rivers and the proliferation over the years, it would not be long before indigenous species became depleted, or in the worst-case scenario — extinct.

“Although there are no records on when these fishes were released into the rivers, it is believed that some of these predators have been set free by hobbyists since the late 1980s.

“After such a long period, there is concern over the loss of aquatic biodiversity due to the introduction of these predatory and invasive species.

“A good example is the invasion of the red claw crayfish in Johor rivers,” he said.


As more of these predatory and invasive species being landed by anglers, it speaks volumes on the declining population of indigenous species.

“The Malaysian Quarantine and Inspection Services (Maqis) needs to tighten its supervision of live fish imports.

“Equally important, the live fish traders must be more responsible by providing the list of their imported fish to the Fisheries Department,” he added.

The next step is honesty in declaring the imported fish as true to the invoice.

The Fisheries Department and Maqis can also deter the import of banned species by explaining the laws and the penalties to importers. They should not entertain “I don’t know” excuses to escape punishment. Amirrudin said fisheries inspectors must be well-informed about banned species and able to identify the fish at first glance and at its juvenile stage.

Local fish shops and hobbyists also must be educated on the prohibitions.

Local fish shops, especially, must be required to display the list of banned fish at their outlets.

“A hotline, or toll-free telephone number to the Fisheries Department should be displayed as big as the ‘No Smoking’ signage in the shops to allow the public to report sales of banned species,” he added.

He said fish farms must not be allowed to breed certain species, especially breeders who grew the fish in cages along rivers and in lakes, because most of the catfish species from the Amazon rivers, for example, could grow to monstrous sizes.

“In some years, we hear reports of fish cages being damaged and African catfish escaping into the rivers in Terengganu, Pahang and Perak. Unless a foolproof method is found, these fish should be bred in ponds,” he added.


Similarly, anglers share the same responsibility.

Any predatory foreign species caught must not be released back into the river. Predatory fish such as pirarucu (Arapaima gigas), alligator gar (Lepisosteus), peacock bass, Chao Phraya high fin giant catfish (Pangasius sanitwongsei) and red tail catfish (Phractocephalus hemioliopterus) have been reeled in by anglers in most major rivers in the country.

When such fish snaps up the baits from rods and lines, it reflects a horrifying reality that the population in these rivers have grown.

And the sizes of the peacock bass, red tail catfish and Chao Phraya high fin catfish which look like the local patin, commonly indicate that these predators have been in the rivers for more than two years.

Religious and cultural releases (bayar nazar) of African catfish, which can grow to an enormous size, by the community should be replaced with the release of indigenous species such as lampam, baung, kelah or the smaller local catfish.

“The Fisheries Department should conduct a careful study on whether a fish species is safe for the biodiversity before introducing it for economic purpose.

“What use is development and intense food production if they cause the extinction of natural assets?

“When the natural resources are damaged by aquaculture or development, it can only be called destructive,” Amirruddin said.

State Fisheries Department director Zawawi Ali said hobbyists generally dumped predatory fishes into rivers when their pets could no longer fit into their tanks or when they lost interest in the hobby.

“Feeding big fish is costly. This may also be another reason they have to dispose of their pets,” he said, adding that the problem would arise when hobbyists imported predatory fish species without verifying with the department whether the species was banned.

Alien fish invasion: Local importers at fault

ROSLI ZAKARIA New Straits Times 17 Apr 17;

KUALA TERENGGANU: Dishonest importers who manipulate procedures are to be blamed for the entry of banned fish species into the country.

They bring in the banned species with those allowed by wrongfully declaring import documents.

Some fish like the pacu, which is closely related to the piranha family, or the Chao Phraya high fin giant catfish (Pangasius sanitwongsei) which looks like the local patin, would be difficult to identify when it is small.

The similar appearance can dupe anyone into thinking that these fishes are safe to be grown in the aquarium until they become large enough to be identified as predatory or banned species.

Unless Customs officers stationed at entry points are trained to visually detect banned species, chances are it will go through and end up in the many water bodies nationwide.

Sources close to the ornamental fish industry said there were not many importers of fish species because of the stringent process of obtaining a licence from the Fisheries Department.

“But huge profits made from high price tags on predatory species attract many to the illegal trade,” he said, adding that many end up borrowing, sharing or using the licence of others to bring in their stock.

“At the end of the day, when the fish arrives, they will still need the services of agents or handlers to clear the fish at the Customs checkpoints.

“This is where dishonesty becomes a factor that enables fishes in the banned list to get cleared.

“Fish can also be smuggled in luggage, mineral water bottles, thermos flasks and plastic bags at border checkpoints.

“Some of these smugglers also come prepared by manipulating the labelling of the species and declaring much lower prices for a banned or exotic species,” the source said.

Unless the loopholes are plugged — indigenous fish in Malaysia will continue to be threatened.

Banned foreign species also bring about diseases that can destroy the population of aquatic life in natural water bodies where they are released.

Alien fish invasion: Peacock bass taking over
ADIE SURI ZULKEFLI New Straits Times 17 Apr 17;

PADANG BESAR: FOR the past year or so, Abdul Azhar Abdul Aziz, 29, a freshwater fishermen at Timah Tasoh Dam in Padang Besar, Perlis, has been earning a side income by renting his boat to anglers.

The state water catchment area is fast emerging as a hotspot among avid anglers in the northern states, who crave the thrill of catching the prized peacock bass, or ikan raja, as it is known among the locals.

Despite the boon, Azhar could not hide his grave concern, which is also shared by dozens of fishermen, whose livelihood depend on catching native fish species, such as lampan, tilapia and haruan in the man-made lake.

While the peacock bass attracts sports anglers, the species is also a ruthless predator.

Azhar could not tell how the peacock bass, which originated from Brazil, found its way into the lake, but the locals believed that it was released by those who reared the fish in aquariums.

“I think we began realising its presence less than two years ago, and ever since then, I noticed that we have been catching fewer native fish species.

“Until now, I could say the number of local fish that we are landing has dropped by almost 20 to 30 per cent, while the number of ikan raja is increasing tremendously,” he said.

While the peacock bass is popular among anglers, the fish does not have commercial value because the flesh is tasteless.

“Last year, the state Fisheries Department released 50,000 lampan fry into the lake to improve the native fish population .

“We had a rude shock when we saw how they were swarmed and eaten up by the peacock bass, and I think only a handful of the fry survived,” he said.

What worried him most was that some of the fishermen and local folks had spotted the peacock bass swimming in rivers downstream.

“The Fisheries Department told us to catch the ikan raja as many as possible and throw them away. We are also encouraging anglers to take home the fish.”

Azhar said he feared that the whole native species in the lake would perish in the next two or three years.

Another fisherman, Haiful Anuar Hassan, 36, said his daily income had suffered a severe plunge from RM100 to between RM30 and RM40 at the most.

A fishmonger, Abdul Wahab Khamis, 60, said his business was also suffered when the fishermen caught fewer native species.

“I have been plying this trade for 14 years and I noticed that the number of ikan raja has been growing rapidly over the last two years. Now it makes up almost 30 per cent of the fishes landed by the fishermen.”

Should this situation continue, chances are, the Timah Tasoh Dam, which is known for its delicious “pekasam fish” made of lampan, haruan and tilapia from the lake, will lose it for good.

Alien fish 'killing' local boat operators
ROSLI ZAKARIA New Straits Times 17 Apr 17;

KUALA TERENGGANU: The invasion of the banned red claw crayfish (Cherax quadricarinatus) in several rivers in Johor has become so devastating that angling boat operators hired by giant shrimp anglers have to literally close shop.

Mohamad Said Hassan, 47, from Tangkak, Johor, who invested his income, partly derived from fishing giant shrimps, in 20 boats, is looking at a bleak future now that anglers no longer hire his boats.

“Business was bad last year. My boats were hired for only one month. I had no business for the rest of the year because the population of the red claw crayfish and African catfish in Sungai Muar has upset the ecosystem,” he said.

“This river used to be a haven for giant shrimp anglers. But now, the baits are either taken by crayfish or African catfish,” said Said, who claimed to have witnessed a group of people releasing three tonnes of catfish into the river to fulfil religious vows.

He said while the African catfish devoured any kind of fish, the red claw crayfish were omnivorous and would eat anything from fish, snails, aquatic plants, algae to sunken wood.

“It is an efficient aquatic scavenger, and for that reason, the red claw crayfish have destroyed breeding grounds of indigenous species and the natural food on which the local species depend,” he added.

Mohd Ilham Norhakim Lokman, 30, a fish seller in Muar, Johor, said he used to catch many giant shrimps, but since last year most of his shrimp traps were filled with crayfish.

He said the crayfish were abundant in the clear river water, brackish water and black water streams as well as in the irrigation canals and in the Bekok Dam in Muar.

Norhakim said he had consulted the Fisheries Department and ichthyologists on the threat of the red claw crayfish, but nothing much could be done to stop the invasion.

“If predatory fish is considered destructive to the aquatic biodiversity, the red claw crayfish is devastative. The damage is done and the days of local aquatic species, including aquatic plants, are numbered,” he added.

The red claw crayfish is native to freshwater creeks and water bodies in tropical Queensland, the Northern Territory of Australia and southeastern Papua New Guinea. It has been widely translocated around the world, and is considered an invasive species.

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