Sidetrack: Chasing Tides in New Zealand

Just came back from New Zealand last weekend, and thought I'll share with everyone some of the marine and intertidal life I saw during the trip :)

The New Zealand shores are certainly very different from what we have in Singapore. One of the most obvious difference was perhaps the kelps stranded on the beach.

They were HUGE!



Kelps are actually brown algae in the order Laminariales, and many marine animals actually feed on them. In New Zealand, I could see kelp forests in most of the coastal area I visited.

At one of the rocky shores, I noticed that most of the tidal pools were covered with coralline algae.



There were lots of mollusks on the rocks. The limpets they have were much bigger then the ones we normally find in Singapore.



I had a pleasant surprise when I saw this little animal among the rocks.



It's a chiton! I've always wanted to see chitons! Have never seen them in Singapore shores. Chitons are mollusks, meaning they are related to things like snails, clams and octopuses. They usually live near the shore, though some species have been found in deep water.

Here's another picture from the top. You will be able to see that it has 8 plates on it's back.



Most chitons eat algae, bryozoans and sometimes bacteria by scraping them off the rocks with their radula. Some species also feed on other small animals.

Walking on the rocky shore, I had another pleasant find - a seastar!



It was quite small, about the size of a 50 cent coin.

Away from the rocky shore, I saw this comical shorebird. It was obviously quite used to human presence, and was walking around examining our legs.



There were quite a few seal colonies along the New Zealand coast too. Here are two New Zealand fur seals.



There was a huge pool of water trapped among the rocks near the coast of Kaikoura, and we saw several fur seals swimming and playing inside.



We also saw several hooker's sea lions at one of the beaches. They were much larger than the fur seals.



But while the adult sea lions look huge and fierce, the juvenile sea lions were really cute.



New Zealand has a resident population of sperm whales near Kaikoura, and so whale-watching was also on my travel checklist. Sperm whales are supposed to be the largest of all toothed whales, and are the largest toothed animals alive. They can grow up 18 metres long!



Whale-watching is basically a waiting game. The ship crew will try to find the whale with a special device, and the ship will just stay around the area and wait for the whale to come up to breathe. We waited between 30 to 40 minutes for the first whale to come to the surface.

Sperm whales are believed to be able to dive up to 3 km deep, and can stay near the ocean floor for up to 90 minutes! So we were actually quite lucky that we didn't have to wait that long. And one top of that, within the short 2 hour plus trip, we spotted not just one, but three sperm whales!



And just before this one dived into the water, I managed to get a shot of it's huge flukes. Not very sharp as it was simply too fast, but still, I'm satisfied!

Semakau Walk on 21 April 2007

Am flying off to New Zealand this evening, so doesn't have much time to blog actually :P

Just a few pictures and some basic notes to record some of the things we saw.

We departed from Pasir Panjang Ferry Terminal instead of West Coast Pier today. Helen found a container with some red seaweed and some anemone inside in the female toilet. The male toilet was quite bare though. Still, the poor anemone probably won't be able to survive long... sigh...

Here a group shot of my group just before we entre the forest. They are from IDA and our group name is Sea Stars.



Even before we enter the sea grass lagoon, we found this scallop (Family Pectinidae).



Scallops are filter feeders - they open their shells slightly during high tide to suck in water and collect edible particles. At low tide, they will shut their shells tightly. Scallops can also "swim" by flapping their valves.

We also saw a pair of common sea stars (Archaster typicus), getting ready to perform external fertilisation.



During high tide, the male (on top) and the female (bottom) will release sperm and eggs together. These sea stars can actually burrow into the sand! As a sea star uses sea water to support its body and move its little tube feet. Thus, never take them out of seawater for too long, as it is very stressful for them.

And here's the traditional shot of the group crossing the sea grass lagoon...



As we stepped onto dry land again, we have this sandfish sea cucumber (Holothuria scraba) waiting for us.



This sea cucumber is edible, but must be properly treated before consumption.

On a rock in the coral rubble, we found a cute little onchidium sea slug (Onchidium sp.)! Can you find it in the photo below?



And of course, there was no lack of the master of camouflage - the hariy crab (Family Pilumnidae)!



It can be quite difficult to spot them sometimes since they blend in very well with the rocks.

We saw several pretty fanworms (Family Sabellidae), and here's one of the orange ones we found.



These worms live in flexible tubes. The feathery fan, which is stuck on the worm's head, is used to filter edible particles in the water so that the worm can feed on them.

We found a lovely sunflower mushroom coral (Heliofungia actiniformis) in one of the tidal pools too.



They usually come in brown, but this one was in a lovely shade of green, probably due to the colour of the symbiotic alge (aka zooxanthallae) which lived in it. The algae can actually provide the coral with food from photosynthesis.

There were lots of other hard corals (below top 2), soft corals (below bottom left), and sea anemones (below bottom right) too.




And we also saw several sponges. Here's a Neptune's cup sponge.



And the highlights of the day were usually these knobbly sea stars (Protoreaster nodosus).



And here's the traditional group shot taken with the knobbly sea stars.



We also saw some egg capsules. These were probably squid eggs.



We also saw a few nudibranchs. The name nudibranch actually means "naked gills". Below is a polka dot nudibranch (Jorunna funebris).



Most nudibranchs can secrete chemicals that make them very distasteful or even toxic, while others harbour stinging cells from the animals they feed on.

The nudibranch below is a pustulose phyllid nudibranch (Pyhllidiella pustulosa), which is said to be able to secrete toxins when they are stressed.



The one below is not a nudibranch though, but a sacoglossan, or what we call a sap-suckling slug. This is probably a Thuridilla gracilis.



They normally feed on algae by biting a hole on the latter and suck the cell sap out of it.

We saw a flatworm (Class Turbellaria) too!



Flatworms are so flat that they can easily crawl into tiny cracks on the rocks to hide from predators and also to find preys.

And here's a noble volute (Cymbiola nobilis).



These huge snail normally feed on clams and other shells.

And there were also two cute upside-down jellyfish (Cassiopea sp.).



This jellyfish has symbiotic algae, mostly in its tentacles, which photosynthesises better with it being upside-down. Some of the food made by the algae will leak and get absorbed by the jellyfish.

And on our way back, I saw a trail and scooping under the sand, I found a moon snail (Family Naticidae). It has a really smooth and pretty shell.



I found a heart cockle too!



Well, on the whole, we had a great trip today. Thanks to all the enthusiastic visitors!