Mass fish deaths at Bishan-Ang Mo Kio Park

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.