12 January 2013

Labrador seagrass monitoring in the rain

Pei Yan and I are back on Labrador to check up on the seagrasses here as part of TeamSeagrass.
Some parts of this beleaguered shore still has good growths of seagrasses and they were blooming!

Alas, the weather turned ugly as soon as we arrived on the shore. We seem to get rain at Labrador, it was also very wet on our last monitoring trip in Nov 12.
When we thought there was a break in the wet weather, we headed out to monitor. Alas, in the midst of monitoring it started to pour again!
I couldn't really get a good look at the Site 2 portion of the shore due to the rain and because the tide wasn't really as low as it should be. What I saw didn't have much seagrasses. Just a few small patches of Spoon seagrass (Halophila ovalis) and one patch of Tape seagrass (Enhalus acoroides).
The seagrasses at Site 1 nearest the entrance to the shore are still doing well!
There were lots of Sickle seagrass (Thalassia hemprichii) with Spoon seagrass (Halophila ovalis) nearer the high water mark, and nice long Tape seagrass (Enhalus acoroides). It was good to see nice long Tape seagrasses, 50-60cm long as they should be. Pei Yan did Site 3. Our sense is that things haven't changed much seagrass-wise since our last Labrador monitoring in Nov 12.
The Tape seagrasses were blooming! I saw one clump with a female flower and a developing fruit. The female flower is on a long stalk with the important flower parts floating on the water surface, waiting to meet with a male flower.
Near the rocky area, I saw several clumps of Tape seagrasses with male flowers.
The male flowers emerge from large bracts that form at the base of the plant (not on long stalks like the female flowers).
Male flowers are tiny and 'stand up' on a wet finger because one end is attracted to water, while the other end repels water. In this way, they float on the water surface and hopefully, meet with a female flower.
Sadly, one clump of Tape seagrass near the high shore had some leaf blades cropped short.
I didn't get a chance to look closely for marine life because of the rain and the short tide window. But there were interesting snails under rocks, a few small clumps of sponges, and some other marine life.
I noticed that most of the Crunchy pom-pom red seaweeds on the shore seem to be 'bleaching'. I'm not sure if this is a natural seasonal part of their life cycle or a sign of some imbalance on the shore.
While waiting for the rain to ease up, I worked on removing some driftnets that had washed up on the high shore. We found three small clumps of nets. We didn't get a chance to check for nets laid out in deeper water as we did on our last trip in Nov 12 when we found a large long net.
The big concrete slab from the Seacil project is still there.
There were also some large pipes that look like leftovers from the Seacil project.

Labrador has the last natural rocky shore in the South (we have natural rocky shores in the North on Changi). It is very close to the massive reclamation for the new Pasir Panjang Container Terminal. The shore was also impacted by a huge trench dug into it (called a cofferdam) to relocate service pipelines to Pulau Bukom.
For years, next to Labrador, there has been massive reclamation, dredging  and other coastal works for the new Pasir Panjang Container Terminal which includes underwater blasting. Hopefully, as the massive construction nearby comes to an end, the seagrasses and other marine life at Labrador can return. It is only through long-term monitoring that we can learn more about what is happening on this shore.

Labrador shore and the jetty are now permanently closed to the public due to safety issues. The natural cliffs along the shore are not very stable. Thanks to Yuet Hsin of NParks for permission to monitor.

Check out Pei Yan's blog for more about our trip.

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