vimeomontage

Sunday, May 29, 2011

black tip reef shark @ Semakau 28May2011

As were were dragging the huge net across the shallow mudflat, I noticed a small white triangular object in the water about 50metres away. I did ask out aloud.. "Hey, what's that over there?" but the rest of the group were too pre-occupied with dragging the heavy carelessly abandoned net in shallow water across the semi-soft mudflat. We had enough to be busy with trying not to trip over the huge net.

After reaching a clear spot on the mudflat where we decided to work on separating the nets, someone exclaimed that the white 'thing' was the fin of a shark on its side. Instantly, the whole group of eight forgot about the nets and headed towards the white fin.

It was a male black-tip reef shark and quite clearly either really comatose or really dead although it looked perfectly fine and healthy. No signs of trauma on its body at all. Still just to be sure, we made sure to keep our hands away from its mouth in case it came to.

There was only a tiny (about 5mm x 0.5mm long) marine leech wriggling on one side of the shark's body. At 1.2m long, the shark was heavy too. I estimated its weight at between 10 to 15 kilos.

James did his best as a shark whisperer to try to see if it would regain its glory and come to life. He even tried 'swimming' the shark in the shallows by giving it a boost pushing its tail hoping that some speed through the water would do it some good but it was already past its time. (We did suggest to him to try CPR but he respectfully declined.)

None of us could figure out why the healthy looking specimen was dead on its side. It did not look like it had gotten caught in some fisherman's net or line. Perhaps it was just its time. At 1.2m, this may be a normal adult size for this particular species of black tip reef shark.

We left it in the shallows where we had found it.


trying to swim the shark through the water...a futile little attempt.

checking the body for signs of trauma....none found!


See also Ria's WildShores blogpost about the shark and net clearing : http://wildshores.blogspot.com/2011/05/shark-on-semakau.html

Saturday, May 28, 2011

fish net cleanup @ semakau 28May2011

A sprightly group of 8 volunteers made their way to Pulau Semakau's intertidal mudflats with a mission to rid one of the mangrove trees on the intertidal  of some carelessly discarded fish nets which had become wrapped around it and which was threatening its survival.

See http://sgbeachbum.blogspot.com/2011/05/abandoned-fish-nets-semakau-21may2011.html for an earlier post when the nets were first discovered.

Leaving such nets without removing them can result in quite a few undesirable consequences. Due to the influence of the tides and incessant wave action, the nets may damage the tree by breaking its branches, 'suffocating' the trees by 'strangling' the trunk, branches and roots preventing the tree from growing normally. Further, such nets can cover prime mudflats available for seedlings to lodge and sprout. Singapore's already limited mangrove habitats are thereby even more limited by such 'litter'. The nets may also continue to trap intertidal animals, such as shore crabs, horseshoe crabs, fish, shore birds, monitor lizards etc.

It took quite a bit of work to remove the net from entanglement with the tree. Then we had to pile it up into a manageable bundle to move it to the extraction point some 200m away. At that point we thought that the entire bundle was made up of a few nets entangled together as there were three distinct hole sizes. We decided to move the bundle as it was to a more open part of the mudflats and the best way to do that was to float the bundle across the shallows. This involved a 150m trek on the mudflats through the shallows tugging the nets. All throughout the watery trek, we were mindful of having personal encounters with Mr Stone Fish. Semakau's shores are known to have stonefish. Indeed, one of the volunteers did have such an encounter on a submerged reef across from Semakau during an intertidal reefwalk about 1.5 years ago. He was evacuated, had a week's stay in the hospital and took some time after that to fully recover from the 'sting'. Luckily, we did not encounter any stonefish ... but we did encounter a black-tip reef shark. (See this link for more info).

On stretching the nets out, we realised that there were 3 nets all joined together to form one huge mega-net. It is very likely that the mega-net was used in a fish-farm type setting. Incidentally, there is a large floating commercial fish farm located a little further south along the Semakau coast.

We cut up the nets into smaller sections for easier portage. Later we had to carry these another about 500m through the Semakau forest trail to the access road for disposal.


The huge nets covering the still live tree.
Checking out the size of the nets.

The different coloured threading shows where nets have been joined to form a much larger net. 

The blue threading here joins nets with larger holes.
Stretching out one part of the mega-net on the mudflat

This is a huge net! Not the kind fishermen would use but the heavy duty kind used on fishfarms for their pens.
The 8 bags of nets all wrapped up ready for disposal. It took 8 volunteers about 2 hours to clear the nets  from Semakau's foreshore.


[Many thanks to NEA for facilitating the volunteer effort and for arranging the removal of the cleared nets!]



Read more about the effort at the Project Driftnet Blog.

Monday, May 23, 2011

red squid stranded @ t.bemban besar 22May2011

This little squid was stranded in a small puddle on a sandbank just metres away from the vast sea.



It must have been caught off guard as the tide was running out and had to stay put in the puddle to await the return of the rising tide. In the meantime, it faced certain risks such as being discovered by shorebirds such as herons and egrets and also risked being turned into squid soup due to it being a clear blue sky morning with the sun shining with all it's glory.

The birds were probably kept at bay because there were some other nosy bipedal morps walking that section of the exposed submerged reef that morning.

daylight hunting octopus @ t.bemban besar 22May2011

It was surprising to see not one but two small octopus out hunting in broad daylight. Normally, octopus are seen on an exposed submerged reef at night or in the early hours of the morning.

These actively went about using their tentacles to probe around and under rocks, coral and sponges looking for food such as crabs and small fish.

Saturday, May 21, 2011

abandoned fish nets @ semakau 21May2011

res ipsa loquitor


Where could this bundle of heavy duty fish nets have come from?
The pile, made up of two or three large heavy duty nets, was freshly washed up ... probably within the day as it was relatively easy to extricate parts of it from the tree they were wrapped around. Given that the bundle had stayed together in a small tight bundle, it is probable that the bundle had not travelled far at all before coming to rest around the mangrove tree on the Semakau foreshore.

there was at least one crab stuck in the netting. 
leaves and branches of the tree caught in one of the nets










Close-up showing the heavy-duty nets. The red 'thread' joins two parts together.



Wednesday, May 18, 2011

apathetic fishermen III @ SBWR 15May2011

Here we go again...


The first half shows a young man well prepared for his poaching expedition on his kayak armed with a fishing rod, water, sunshades and visor (inter alia). He even had an air-filled plastic bag presumably containing some fish. He had found his way around Pulau Buloh within a stone's throw from Platform 2 and just outside of a sluice gate probably hoping to land a good catch. Instead he was caught by two park visitors who made prompt telephone calls to the park rangers which caused him to pack up and flee towards Platform 1. On seeing the ranger beckoning for him to come 'ashore', he quickly turned his kayak and paddled out towards Kranji.

The second half of the clip shows a yellow-shirted man ("YSM") with a cast net walking across the mouth of Sungei Buloh Besar. The tide was low enough for the walk but the YSM failed to net anything significant except some very small fish. (The bigger fish had probably already been prevented from coming in due to the long gill/drift nets placed a little further out by the other fishermen.) This YSM disappeared into the mangrove at the east bank. He would probably walk out towards the Kranji Nature Trail.


Let's have a look at relevant legislation :-

Restricted activities in respect of animals, etc., in national parks and nature reserves
9. —(1) No person shall, except with the approval of the Commissioner granted under section 12 and in accordance with the terms and conditions of such approval, carry out any of the following activities within any national park or nature reserve:
(a) capture, displace or feed any animal;
(b) disturb or take the nest of any animal;
(c) collect, remove or wilfully displace any other organism;
(d) use any animal, firearm, explosive, net, trap, hunting device or instrument or means whatever for the purpose of capturing any animal; or
(e) carry or have in the person’s possession any explosive, net, trap or hunting device.

(2) No person shall carry out any activity within any national park or nature reserve which he knows or ought reasonably to know causes or may cause injury to, or the death of, any animal or any other organism within the national park or nature reserve.

(3) No person shall, except with the approval of the Commissioner granted under section 12 and in accordance with the terms and conditions of such approval —
(a) bring or release or cause any animal to be brought or released into a nature reserve; or
(b) permit any domestic animal to stray into a nature reserve.

(4) Any person who contravenes subsection (1), (2) or (3) shall be guilty of an offence and shall be liable on conviction to a fine not exceeding $50,000 or to imprisonment for a term not exceeding 6 months or to both and, in the case of a continuing offence, to a further fine of $500 for every day or part thereof during which the offence continues after conviction.