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.