Other intertidal surveys: Mar 2026

Thanks to Marcus for visiting Cyrene in March so we could get an update on the mass injuries we saw to the Knobbly sea stars that we observed in Feb  2026.

Collage of photos by Marcus Ng.

Marcus photographed 14 Knobblies on his Mar 2026 visit. Although all of them appear healthy at first glance, a closer look at the top 5 knobs shows that 10 sea stars (or about 70%) show recovery from damage. Where the top 5 big knobs should be, there was a sheared flat surface - which were a dark colour and thus seem 'healed', not greyish-blue as we observed in Feb  2026. Others had dark patches at the top and the knobs were missing or seem a little 'limp'. One had knobs that look like they were starting to separate at the base from the main body. One pale sea star had three knobs instead of one large knob. Only 5 sea stars seem normal. Again, still not sure what is going on. But at least there isn't new damage?

In Feb  2026, we observed up to 70% of the sea stars on Cyrene were damaged. 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.

In the Mar 2026 visit to Cyrene, Zen saw what looks like some dugong feeding trails, faint as the seagrass cover on Cyrene is now 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. Zen and Marcus saw lots of Polka-dot nudibranchs - they were abundant on all shores we surveyed this cycle. Also interesting fish and other marine life. The hard and soft corals looked well.

Collage of photos by Marcus Ng and Zen Xuan He.

There were also visits to Chek Jawa and other shores between the super low tides. Thanks for keeping an eye on our shores.

Zen Xuan He helped researchers Chek Jawa on 3 Mar and got some glimpses of the shore.


Marcus Ng checked up on Cyrene on 23 Mar.


Zen Xuan He was kindly invited to join Marcus at the Cyrene survey on 23 Mar.