Saturday, May 28, 2011

Pulau Semakau (28 May 2011)

Volunteers today removed a huge heavy duty net that washed ashore on Pulau Semakau.
It was a very large and heavy net! Back breaking work in the hot mid-day sun on a not-so-low tide.

Andy first spotted the net during the TeamSeagrass trip last week to monitor our seagrasses. As usual, we don't have time to do both monitoring AND net removal. So we have returned a week later to tackle this net.
Nicole helps to measure the mesh size. We find a broad range of sizes! From 25cm, 15cm, 8cm to 2.5cm! Are these several layers of nets?
The first job was to remove the net from the small mangrove tree that it has landed on. We do it gently and it was quite simple to remove as the net seems to have only recently landed on the high shore. It's important to remove such a heavy duty net as otherwise it will interfere with the growth of the mangrove trees. As we discovered when we removed a very old net at Kranji recently.
Then we had to remove the net from the shore. We decided to move it on the water where there are fewer living things (the high shore was full of mangrove roots). And in the highish tide, the net actually floated a bit and was easier to move.
Fortunately, the net is made from heavy ropes which don't entangle marine life like the nearly invisible monofilament driftnets do. But small creatures do get 'lost' within the maze of this huge net. We release two small swimming crabs from the net. They were very much alive. One small fish was also found, probably it got stuck when we were removing the net to the high shore. It too was released safely.
When we get to the high sandy shore mostly devoid of marine life, we start to unwind the net.
Halfway unwinding the net, Marcus spots a big white thing in the water, quite a distance from where we were working. We drop everything to have a closer look. It's a shark! More on the wild shores of singapore blog.
Then it's back to unwinding the net. It is humungous!
This is just a small portion of the entire bundle of nets. We measured on end of it and it was about 25m wide! We couldn't measure the entire length but in volume it was 3.5m x 2.5m x 1m or nearly 9m3.
We look closely and realise it is one single continuous net, with different mesh sizes sewn together.
Then it's time to cut up the net into smaller bundles so we can heave it out to the main road.
After some time, we have the net all packed up and ready to go.
We didn't have time (or energy) to check out the Northern shore for driftnets seen last week. But we didn't see any suspicious floats, nor did we see any small boats near the shore.

A back breaking haul and we manage to get all the nets out to the road where NEA will dispose of them properly.
Thanks to Sean for burning his Saturday to take us out and bring us back for this trip. And Jinny and friends at NEA for permission to visit to get this job done.

Special thanks to Marcus, Nicole, Andy, James, Jerome, Ivan and Liana for removing the net!

These heavy duty nets are not used to catch fish the way monofilament driftnets are. The net is likely to have come from a fish farm. There is a farm very close to Pulau Semakau. We also had a look at some other strange contraptions on Semakau that look suspiciously like they belong to the nearby fish farm too. More on the wild shores of singapore blog.