Media articles reported that thousands of small 5cm long dead fishes "were found at the mouth of Sungei Api Api and along Pasir Ris beach" on 20 Mar.
Dec 2009 where the beach was littered with hundreds of dead fishes of all kinds?
Sungei Api Api seems clear of dead fishes, both the muddy banks a little further up the mouth of the river (photo above), and at the sandy banks near the mouth (below). There was a whiff of dead fish though, at the bridge. It smelt more like being at a salted fish factory than nauseating.
Sea lettuce green seaweed (Ulva sp.). I didn't find any dead fishes of any kind among the seaweeds.
Mangrove horseshoe crab (Carcinoscorpius rotundicauda).
Flower crabs (Portunus pelagicus). I checked for transparent eyes, to confirm that they are moults and not dead crabs.
Spoon seagrasses (Halophila ovalis). These seagrasses are quite lush lower down where it's more often submerged.
hermit crabs (Clibanarius sp.) out and about despite the rain, the rocky shores had Drills (Family Muricidae) busy laying eggs, I saw a couple of moon snail sand collars and some burrowing sea anemones.
a conscious decision by NParks to re-establish the original mangrove habitat there after reclamation at Pasir Ris and works to deepen the Sungei. The experience in this experiment was not only applied to Sungei Tampines which lies nearby, but also to mangrove restoration at Pulau Semakau!
Further upstream, however, the Sungei is canalised. Here, I saw a large construction site for the Belysa Executive Condos.
In February 2011, Grant Pereira shared about several incidents of pollution that killed off marine life at Sungei Api Api.
In media reports, PUB said "(The fishes) were likely to have been washed in by the tide, and some of them were deposited on the river bed of Sungei Api Api. The contractors are currently clearing the dead fishes". The foreman of the crew who have been cleaning Sungei Api Api for two years told the press that he thought the dead fish came from Serangoon Harbour, near Pulau Ubin
"PUB assures the public that this incident has no impact on drinking water quality. The water in Sungei Api Api is not used for the drinking water supply." The National Environment Agency is also investigating the cause of the incident.
Update 22 Mar: A new media report says "NEA has ruled out water contamination as the cause of their deaths. It said yesterday that it analysed water samples from the area and did not detect any irregularities. There was also no discharge of toxic chemicals or pollutants into Sungei Api Api on Tuesday." Also "Fish farmers there have not reported any fish dying in their farms. Algae blooms which kill fish have also not been reported in the area recently."