Saturday, June 19, 2010

Exploring Sekudu on 16 Jun 2010

This is a slightly overdue entry again. We made a trip to Pulau Sekudu last Wednesday to check on the situation there after the oil spill. Pulau Sekudu is part of Chek Jawa Wetlands, and hence is a protected area. As such, we had to get a permit from NParks before we can go there.

When we reached the island, we were glad to see that the oil spill did not appear to have affected it. We did not see any huge patches of crude oil. It started raining soon after we reached the island though, and hence we can't exactly tell if there were any oil stains on the wet rocks.

We did not managed to explore the island properly due to the rain, and in fact, many animals were probably hiding from the down pour. But still, we managed to see a number of marine organisms before the rain eventually got too heavy and lightning started flashing.

Cake Sea Star (Anthenea aspera
We found several orange-coloured Cake Sea Stars (Anthenea aspera). Most of them were less than 10cm wide though. Not sure where did the bigger ones go.

Biscuit Sea Star (Goniodiscaster  scaber)
There were many Biscuit Sea Stars (Goniodiscaster scaber) of various sizes. However, they appeared to be less abundant compared to last year.

Luidia  maculata
Forgot to wipe away the water droplets on my lens, and hence this Eight-armed Luidia Sea Stars (Luidia maculata) appeared slightly distorted. This sea star feed on other smaller sea stars!

Knobbly Sea Star (Protoreaster nodosus)
We found 2 rather huge Knobbly Sea Stars (Protoreaster nodosus)! It got its name from the nodules on its top side.

Feather Star (Class Crinoidea)
We found 2 Feather Stars (Class Crinoidea) too! These animals gather small food particles in the water using their feather-like arms.

Pencil Sea Urchin (Prionocidaris sp.)
There was a Pencil Sea Urchin (Prionocidaris sp.) at the coral rubble area. The water got too murky further out, and hence we did not venture further to try to find more of them.

Salmacis Sea Urchin
The Salmacis Sea Urchin (Salmacis sp.) appeared to be in season, and we saw many of them. Most of them had bits and pieces of shells, twigs or seaweed stuck to them for camouflaging.

Ball Sea Cucumber (Phyllophorus sp.)
There were several Ball Sea Cucumbers (Phyllophorus sp.), though certainly not as abundant as last time.

Paracaudina australis
A few translucent sea cucumbers were found, probably Paracaudina australis.

Sea Pen (Order Pennatulacea)
Among the seagrass, I found quite a number of Sea Pens (Order Pennatulacea).

Stinging Hydroids (Class Hydrozoa)
There were clusters of Stinging Hydroids (Class Hydrozoa) too! These plant-like colonial animals can give nasty stings when touched.

Haddon's Carpet Anemone (Stichodactyla haddoni)
There were many huge Haddon's Carpet Anemones (Stichodactyla haddoni) among the seagrass, and quite a number of them were at least 40cm wide. These anemones have sticky tentacles to sting and stick small prey like fishes or crustaceans.

Swimming Anemone (Boloceroides mcmurrichi)
Swimming Anemones (Boloceroides mcmurrichii) appeared to be in season too. These sea anemones do not attached themselves to the substrate, but are free-living! They can swim by pulsation.

Soft corals
It was nice seeing so many brightly-coloured soft corals.

I found a transparent shrimp living on one of them. Looks very much like some kind of snapping shrimp, but can't say for sure.

Ghost shrimp
There was a ghost shrimp out of its burrow. Not sure about the species though.

Blue Dragons (Pteraeolidia ianthina)
Some of the volunteers found 2 Blue Dragons (Pteraeolidia ianthina) together. Wonder what they were doing?

Blue Dragon (Pteraeolidia ianthina)
Here's the bigger one when they moved apart. This nudibranch feeds on hydroids, and is able to store the latter's symbiotic algae in its body for photosynthesis. The algae will provide nutrients for the nudibranch. At the same time, it can store the stinging cells of the hydroid and use them for protection against predators as well.

Denison's Nudibranch (Dendrodoris denisoni)
Another nudibranch we saw was this Denison's Nudibranch (Dendrodoris denisoni). Unlike the Blue Dragon, this nudibranch feeds on sponges by secreting enzymes to digest them externally before sucking them up.

Natica zonalis
We saw a few moon snails, including this Natica zonalis.

We also saw a few octopuses. They are among the smartest invertebrates around, and are known to be able to learn by trial and error.

Razor clam
We also saw a few razor clams. This one was next to an anemone.

After exploring for about an hour plus, the rain got even heavier, and soon, we could see lightning too. For safety reasons, we decided to take shelter near the big rocks at the centre of the island.

Due to the storm, we did not managed to explore most part of the island, and many of the organisms were probably hiding. However, we were still very glad that we had made this trip, as we could now be sure that Sekudu was indeed spared from the oil spill.

1 comment:

koksheng said...

Good to hear that Sekudu is not affected by the oil spill :)