Friday, August 9, 2013

Driftnet traps sharks, horseshoe crabs, stingrays on Pulau Semakau (9 Aug 2013)

Sadly, but not surprisingly, we came across a driftnet during our National Day visit to Pulau Semakau.
In the short portion of the net that I surveyed, I saw 14 horseshoe crabs that were still alive and struggling and seemed freshly entangled in the net. Including two pairs of male and female. They all looked like Coastal horseshoe crabs.

Even before we landed, we saw someone with a very powerful torch walking about on the shore. As we were landing, the person moved up onto the main seawall around the big lagoon. But after we landed, I noticed the person was back on the shore. I kind of headed in the person's direction in the hopes of chatting and finding out what he  was doing there. As I got closer to the person (torch arrowed), I came across a long net.
I also came across five dead Blue-spotted fantail rays, four about 30cm long (body only) and one was much smaller.
I also saw two small Flower crabs and one half-eaten fish.
I also came across this half eaten fish upstream.
The net was draped over stretches of seagrasses. The Tape seagrasses are getting cropped for some unknown reason over much of Pulau Semakau. It is now not so common to see long Tape seagrasses here and such a shame if such seagrasses are ripped up with the driftnet.
Here's a slideshow of some of the animals I saw trapped in the net.

Created with Admarket's flickrSLiDR.
I didn't have the heart to walk to the start of the net, but Kok Sheng did and said he saw three small sharks that were covered in flies. Read Kok Sheng's blog post for more photos of the animals he saw trapped in the net.
Photo by Loh Kok Sheng
I walked until the landward end of the driftnet and saw that it was tied to a mangrove tree among the replanted mangroves. In the end, I couldn't catch up with the person before he disappeared in the darkness. We're not sure if the person laid the net. Perhaps we disturbed him clearing the net?
We estimate the net is about 150-200m long and its approximate position on the shore is the yellow line on this screen shot.
This shore is just opposite a fish farm. In May 2011, a small team valiantly removed a huge net that probably came from the fish farm. We don't know where this person that we saw today came from. A worker based on the Landfill? A worker on the fish farm? Or some other person?
People on a large floating structure near the fish farm.
We usually do not remove a net if the person who laid it is nearby or on the shore. In the hope that the person will remove the net. In our experience, we find that if we cut up the net to release the animals, the person who laid the net will simply abandon the net and this will cause an even bigger problem as the net will continue to entangle sea creatures until it is removed.

Driftnets are heartbreaking to encounter and even more heartbreaking to walk away from with animals trapped in them.

More about happier sightings on this trip, as well as other threats to this shore on the wild shores of singapore blog.

1 comment:

  1. It seems likely that the fish farm workers may have set the net up.