wild shores of singapore: Mass injury of Knobbly sea stars at Cyrene

01 February 2026

Mass injury of Knobbly sea stars at Cyrene

Although Cyrene lies in the middle of an industrial triangle, it still has some of Singapore's most amazing shores. A very large team surveys today.

Dugong feeding trails in seagrass meadows, Cyrene, Feb 2026

Alarmingly, we found most of the Knobbly sea stars had mysterious injuries. Seagrass cover was very thin, but dugong feeding trails were still seen. The rest of the team as usual make all the special finds. From Giant clams to interesting sea stars and sand dollars. I will update when they have uploaded their photos.

We saw the usual clusters of Knobbly sea stars at the usual spots in various parts of the reef edge; from a handful to 10-20 individuals. For the first time, we observed up to 70% of the sea stars were damaged. The top-most 5 large knobs were missing - the greyish-blue area of cut tissue was firm, not soft. All other knobs were alright. Examining some undersides, I didn't see any damage. Although some sea stars had sheared off arm tips as well. There were some that were perfectly alright, and some with regenerating arm tips. I have no idea what is going on. We hope this isn't an ominous sign. On our last survey in Jul 2025, we already noticed the shores here were rather quieter than usual.

Kok Sheng is the only one in our team who checked up on all the locations where these sea stars are usually found. He noted of those on the eastern shore near the beacon. about 30% had this injury. While 70% of those nearer landing point on the northern shore facing Pasir Panjang Container Terminal were affected. From his photos, Marcus saw 14 Knobblies at the western shore (nearer Jurong Island) and none them seem affected. In many affected stars, the top five knobs were lost. In some, only a few of the top 5. From Kok Sheng's photos, it seems the knob fell off, rather than being bitten off by predators. The cut is clean and sheer, and there is even one photo with the knob still hanging on by a bit of tissue. So possibly the sea stars self amputated their knobs, the same way that they can do with their arms? We are still checking with science and aquarist experts to get a better understanding of what might have happened.

Collage of photos by Loh Kok Sheng.

Today, I saw some dugong feeding trails at our landing point north-westward facing Pasir Panjang Container Terminal. But they were faint as the seagrass cover was very thin. These trails are formed when dugongs chomp up seagrasses including their roots, leaving a shallow meandering furrow of about equal width and depth. Every survey since 2021, we see dugong feeding trails on Cyrene. We also saw many patches of bleaching Spoon seagrass near the landing point.

As usual, the team make all the special finds: the colourful pink shrimp-goby that lives with a snapping shrimp, 'Nemo' and other lively fishes. There were also some Common sea stars and Kok Sheng saw many Key-hole sand dollars - which we seldom see anywhere else. There were special snails, octopuses, colourful crabs and slugs too.

The team together found 3 large Fluted giant clams (30-40cm).

There's never been a lot of hard corals on Cyrene since we first started surveying it. Most of them are boulder shaped and there are some large colonies. I had a brief look at the corals on the eastern end today. Similar to our last survey in May 2025 and Jul 2025 today I didn't see any bleaching.

Near the beacon and around the eastern tip of Cyrene, there remains many large Leathery soft corals of various kinds. As well as some Asparagus flowery soft corals. Similar to our last survey in May 2025 and Jul 2025 today I didn't see any bleaching, today I didn't see any bleaching soft corals.

I'm trying to be more diligent about documenting seaweed blooms. Today, all around the reef flat, Sargassum is still in bloom, so thick that they made the amphibious dinghy landing more difficult.

A strange experimental set up was seen. We asked around and still can't find out what it's about. One broken fish trap was also seen.

Although it lies in the middle of an industrial triangle and major shipping lanes, Cyrene has some of Singapore's most amazing shores. We had surveyed in Jun 2024 for impact of the Pasir Panjang oil spill a few weeks prior and did not see any signs of oil. While Cyrene seems to have pulled through both this oil spill and mass coral bleaching that happened in 2024, it seems to be growing more quiet. We shall monitor closely and hope it will recover.