16 December 2016

East Coast Park's sandy shores with seagrasses

The reclaimed sandy shore of East Coast Park are alive! I made a solo visit near sunset with hardly anyone else on the shore.
The sand was alive with Button snails and sand dollars, and the nearby seagrass patches are still lush. But I didn't see any sea cucumbers, sea stars, anemones or special snails.



Lush seagrass patches between the canal and the broad sand bar seems to be growing wider and also extending into deeper water.
Most of the seagrasses were Spoon seagrass with large leaf blades, and Needle seagrass with broad leaf blades. There were also patches of Needle seagrass with narrow leaf blades.
There was also a small patch of Sickle seagrass.
I couldn't find many animals in the seagrass patches. Only a few large Fan shell clams, and many Thumbs up ascidians. I didn't see any anemones, sea cucumbers, sea urchins or sea stars. We saw a lot more on our last survey here in Feb 2016 and Jun 2015.
Seagrasses were also settling on the western side of the large sand bar.
The sandy area is teeming with Button snails! First sign of Button snails are lots of shells of dead snails. No two shells are exactly alike!
Button snails have a very long leaf-like foot. Which they can use to quickly burrow into the sand.
When unearthed in water, I notice Button snails tend to pop up to the water surface and form rafts. They then drift away before sinking down into the sand a little further away. Is this a way to avoid burrowing predators?
And here's one burrowing predator: The Moon snail. You can see the little Button snails attempting to escape. Harder to do out of water. All the moon snails I saw were Ball moon snails. There were also many Spiral melongena snails and a few Gong gong snails. I also saw several Acorn worms.
Ploughing through the sand were many small Weasel olive snails, leaving their typical furrows.
There are lots of Cake sand dollars everywhere near the low water mark. Most are tiny with some small ones. I couldn't find any snails that eat them such as the Fig snail and Grey bonnet snail which we saw on our last survey here in Feb 2016.
There were many Orange-striped hermit crabs. Many in clusters. Getting ready to mate?
After the sun set, I noticed fishes in the sand. They are superbly camouflaged. This one is a Smallheaded dragonet.
This one is a Bar-tailed flathead.
I was surprised to see several Sally-light-foot crabs in the water. I always thought these crabs only hunted among the rocks.
As it got dark, a lot of Blue swimming crabs started foraging in the water. There were also many little Flower crabs.
I noticed some foreign workers foraging on the shore near the seawall. There were also also large trash on the shore: traffic cones, a broken TV, but no fish traps or nets.
I'm not sure why I saw so few animals on the trip. But it was good to see the seagrasses doing well. Let's hope the animals will come back.