The striking pink waters at Sentosa Cove recently bewildered residents and intrigued netizens.

The entire waterway along the South Cove around Sandy Island was coloured a rouge pink, and residents said they detected a foul rotting smell.

No dead fish, but stench remains

When Mothership went down to check out the situation on the morning of Jan. 14, the waters were grey with a slight tinge of purple.

There is however, the possibility of the waters turning pink again later in the day.

On Jan. 13, a Sentosa Cove resident told Mothership that the waters were grey in the morning, but the pink hue slowly bloomed throughout the day until the entire waterway turned a pink-purplish at around 3pm.

Today, there was also no dead fish in sight.

This observation was corroborated in a statement by Sentosa Cove Resort Management (SCRM), who told Mothership that they are aware of the reports of dead fish in the waterway of South Cove on Jan. 9, and have since taken action to remove the dead fish from the waterway.

In spite of the absence of fish carcasses though, the foul stench lingered in the air, and can be detected even through one's mask.

"Brimming with wildlife"

On the ground, most residents were observed to be rather unperturbed, going about their morning routine as per usual.

Most residents Mothership spoke to at Sentosa Cove said this was their first time encountering a phenomenon like this.

Describing the smell as "really stinky", the resident, who has been staying there for six years, speculated that the odour and colour was due to a sewage leakage.

A resident who hails from the Philippines said the pink waters were similar to a "red flood" she had seen back home. "Red floods" are the result of algal blooms by cyanobacteria. She added that she was more worried about the dead fish.

In contrast, another resident claimed to have seen the pink waters a few years back.

Another resident said the situation was "weird", as they "normally get so much wildlife around here".

Seeing the waterways like that was "upsetting" for her.

Wildlife appears to have been a common sight previously. A sign along the waterway states that the canals are "brimming with marine aquatic life", and sea turtles, corals and sea slugs apparently call these waterways their home.

A new development however, appears to be the presence of a purple scum floating on the surface of waters.

A rather prominent patch was seen below a bridge at one end of the long waterway.

It was also spotted below another bridge, drifting inwards.

A Mothership reader and Sentosa Cove resident observed something similar, saying that the scum was now "floating all over the waterways".

"The problem is getting worse every day," he said.

Mothership has reached out to National Environment Agency (NEA) and SCRM about the purple scum, and will update the story when they reply.

No indication of industrial or marine pollution

In response to Mothership's queries, both NEA and SCRM said they were aware of reports of dead fish in the waterway of South Cove on Jan. 9.

The change in the waters' colour was then observed on Jan. 12. Currently, the North Cove remains unaffected.

NEA stated that there is no indication of any industrial or marine pollution which could have affected the waters in the surrounding area.

There were also no reports of dead fish at other public beaches in Singapore over the last weekend.

NEA and the National Parks Board are also assisting Sentosa Development Corporation in their investigations into the possible causes of the dead fishes and the unusually-coloured water.

NEA shared that they have collected several water samples since Jan. 9 and is analysing the results.

As a precautionary measure, SCRM has advised residents to refrain from participating in water sport activities in the waterway. SCRM will continue to monitor the waters.

Top photo from Sentosa Cove resident and Jinghui Lean