Kusu Island with sea krait!

This rich shore lies just opposite the Central Business District, less than half an hour away by fast boat.

The reefs seem to be well and the team get a rare glimpse of a Yellow-lipped sea krait, cone snail and other interesting marine life.

For the last 10 years or so, we see  the Yellow-lipped sea krait less often that we used to. The last time we saw one in Kusu Island was in 2017. I worry that this might be because they have lost their breeding area - these snakes breed on coral atolls and rocky islets where they may gather in large groups to do so. The reef flat at Pulau Sudong used to be a well known nesting ground for the snake until it was reclaimed. The mother snake lays 5-9/7-13 eggs, in caves and grottos. So it was wonderful that Kelvin spotted this snake again today. This gentle snake will not harm if it is left alone. Che Cheng spotted a cone snail! Lee Kiang spotted a fish which at first I thought was a dragonet, but a closer look at the photo shows it is clearly not. Still a mystery for now. 

Photo by Kelvin Yong

The rest of the team saw slugs and interesting fishes. There were also octopuses. On an undisturbed island, there is often lots of Land hermit crabs! Apparently the dark purple ones are a different species from the more brownish ones, but they sure party together when night falls! Also lots of crabs of all kinds.

Collage of photos by the rest of the team.
Links to their albums below.

Outside the sea wall, there were still lots of corals. The tide wasn't very low today so I couldn't get see whether the rare corals are still there. But I saw many boulder-shaped corals, some were doing well, others had dead portions on the top. I didn't see any bleaching corals: species that usually bleach first were doing well. On the jetty legs, there were lots of bright yellow Cave corals that grow in dark places.

Inside the lagoon, the situation seems similar to our last survey in May 2022 and Sep 2023. The field of Branching montipora corals inside the lagoon is still doing alright.

I also saw large colonies of Leathery soft corals of various kinds. As well as many Asparagus flowery soft corals. None that I saw were bleaching.

As on my last survey in May 2022, there is still a high level of sand at the mouth of the northern lagoon. Magnificent anemones used to be plentiful at the mouth - they have move out east of the mouth. They are also now abundant on the reefy area inside the lagoon. I also saw few Giant carpet anemones, Fire anemones and a very large Upside-down jellyfish.

What is the future of Kusu Island?

The cluster of Kusu, Lazarus and St. John's Islands has been recommended by the Singapore Blue Plan 2018 for elevated protection status.

The Blue Plan highlights that Lazarus, St. John’s, and Kusu Islands are established sites for coral nurseries as their shoreline offers ideal sheltered areas for growth of corals. Designating these islands as No-fishing Areas can bolster their rehabilitation. Protecting a larger cluster of islands means zonation plans for use can be implemented to manage tourism and human impacts.

DOWNLOAD the Plan, SUPPORT the Plan! More on the Singapore Blue Plan 2018 site.

Photos by others on this survey

Kelvin Yong


Richard Kuah


Che Cheng Neo


James Koh


Liz Lim


Richard Kuah


Ng Leekiang


Tammy Lim


Tommy Arden


Vincent Choo



During the same low tide cycle, other team members also visted other shores

Marcus Ng checked out Changi and Pulau Hantu


Jianlin Liu checked out Changi