Bishan Park water quality normal despite mass fish deaths: PUB

Despite the death of up to 900 fish in the river running through Bishan-Ang Mo Kio Park, laboratory tests show the raw water quality, including dissolved oxygen levels, is within normal range, PUB says.
Channel NewsAsia 21 Jul 15;

SINGAPORE: About 800 to 900 fish were found dead at the Kallang River at Bishan-Ang Mo Kio Park, but the water quality is normal, said Singapore's water agency PUB.

In a statement, PUB said it was alerted to the problem on Monday (Jul 20) at about 7.40pm. "A site check was carried out immediately and NEA’s contractors were activated to remove the dead fish. Clean-up operations which commenced since last evening at the affected stretch of the river are largely completed," PUB said on Tuesday.

Laboratory tests showed that the raw water quality, including dissolved oxygen levels, is within normal range, the agency stated.

Most of the fish affected are cichlids. Specimens have been sent to AVA for examination, PUB said. Investigations on the cause are still ongoing.

"As of now, the water quality of the river in Bishan Park is normal, live fishes can be seen in the water and the public can continue with their activities at Kallang River @Bishan-Ang Mo Kio Park. PUB will continue to monitor the situation," a PUB spokesperson said

- CNA/ly

Mass fish deaths at Bishan-Ang Mo Kio Park
MARISSA YEO Today Online 21 Jul 15;

SINGAPORE — The public may continue their activities at the Kallang River in Bishan-Ang Mo Kio Park, as authorities investigate what killed some 900 fish there despite normal levels of dissolved oxygen, national water agency PUB said today (July 21).

The dead fish were discovered from last evening and specimens have been sent to the Agri-food and Veterinary Authority for examination, said PUB. “Investigations on the case are still ongoing.”

The PUB checked the site after it was alerted at 7.40pm yesterday.

Contractors of the National Environment Agency were activated to remove the dead fish – numbering about 800 to 900 and which were mainly cichlids – and the PUB said clean-up operations were largely completed as of last evening.

Laboratory tests of water samples collected by PUB along the river showed dissolved oxygen levels within the normal range, said the spokesperson. As of this evening, the water quality of the river in the park was normal and live fishes could be seen, she said.

This is not the first time the park has been hit by fish deaths: Last February, about 400 fish died as Singapore underwent a dry spell. The PUB said at the time that the deaths could be because of lower levels of dissolved oxygen due to hot and dry weather.

Although unaffected, some Bishan residents approached today were surprised to find out about the fish deaths.

Ms Koh Lay Bin, who exercises at the park, said: “I didn’t know that there was clearing of the fishes. (Previously), I have seen several fish that died, probably because the water levels were very low; however I will still see some of them swimming.”

Another resident, Mr Patrick Wong, 60, said: “I don’t really see much fishes along river (when I pass by). It may be due to the shallow waters. However, there are more fishes at the bridges because the water levels are slightly deeper.”

Mass fish deaths have been reported elsewhere in Singapore in recent years. In March, wild fish as well as up to 600 tonnes of farmed fish died in the East Johor Strait off Pasir Ris amid an algal bloom. Last year, a plankton bloom cost fish farmers in both the East and West Johor Straits about 500 tonnes of fish.


Mass fish deaths again at Bishan-Ang Mo Kio Park
PUB says 800 to 900 fish dead in Kallang River; similar incident occurred in February last year
Carolyn Khew Straits Times 22 Jul 15;

Close to a thousand fish went belly up at Bishan-Ang Mo Kio Park on Monday night, in a repeat of a similar incident last year.

National water agency PUB said that the latest incident at Kallang River, which runs through the park, affected about 800 to 900 fish of varying sizes. They were mainly cichlids, a diverse family which includes the popular aquarium fish luohan and the food fish tilapia.

Fish specimens have been sent to the Agri-Food and Veterinary Authority of Singapore for examination, and investigations are ongoing, said a spokesman for PUB. It is monitoring the situation.

While the cause of the mass fish deaths is a mystery for now, experts The Straits Times spoke to suspect that, like the incident in February last year which killed about 400 fish, it could be related to the hot weather and reduced rainfall.

Dr Tan Heok Hui, a fish expert from the National University of Singapore's (NUS) department of biological sciences, explained that this could have led to low oxygen levels in the water. When there is less rain, the water becomes clearer, so sunlight can better penetrate and algae grows faster, explained Dr Tan, who is also a museum officer at the Lee Kong Chian Natural History Museum.

Water samples that the PUB collected for testing showed that the raw water quality, including dissolved oxygen levels, was within the normal range, it said.

The agency received a report of dead fish at around 7.40pm on Monday, and cleanup operations since then have been largely completed, said the PUB yesterday.

"As of now, the water quality of the river in Bishan Park is normal, live fishes can be seen in the water and the public can continue with their activities at Kallang River at Bishan-Ang Mo Kio Park," said the PUB spokesman.

When The Straits Times visited the park yesterday morning, cleaners were still removing the dead fish. Residents in the area said that the dead fish gave off a pungent smell which wafted over to the main road nearby.

Bishan resident Chen Shanshan, 24, who lives at the block next to the park, said that she could see many dead fish floating in the water even from her eighth-floor flat.

"I saw passers-by gawking and taking pictures and then later, when I was crossing the road, I could smell the dead fish stench," said the communications associate.

Dr Chou Loke Ming, adjunct research professor at the Tropical Marine Science Institute at NUS, said the mass fish deaths are worrying, and that it could happen again.

"Most would point to the changing climate and that may indeed be true, but we need to investigate to be sure," he said.