On 16 Aug 2015, the St. John's Island Marine Lab posted on facebook: "This morning, we found 13 juvenile blacktip reef sharks and more than 30 crabs of various species caught in three drift nets at Lazarus Island.
More than 10 blacktip reef sharks, 30 crabs found in fishing nets at Lazarus Island
Audrey Tan Straits Times 16 Aug 15;
SINGAPORE - Thirteen blacktip reef sharks and more than 30 crabs of various species were found in three fishing nets on Lazarus Island, located south of the Republic, on Sunday morning.
Unfortunately, all the sharks caught in the gillnets were dead, although a number of crabs managed to survive after they were disentangled and released by the people who found them.
The St John's Island Marine Laboratory said in a Facebook post on Sunday morning that the shark carcasses are being stored in its freezer and will be passed to the Lee Kong Chian Natural History Museum for analysis.
The lab, which is part of the National University of Singapore's Tropical Marine Science Institute, also called for responsible fishing.
Replying to one of the comments on the post, the institute said that the fishermen who laid the nets "were remorseful and not defensive when talked to about the destructive effects of (the) nets".
The page also noted in a comment: "They (the fishermen) even helped to bring the nets to land. Nobody want this to happen. Let's continue to remind each other on using our nature areas responsibly."
Gillnets are nets typically made of monofilament or multifilament nylon that hang in the water column. According to the United States National Oceanic and Atmospheric Administration, the mesh sizes are designed to allow fish to get only their head through the netting, but not their body. The fish's gills then get caught in the mesh as the fish tries to back out of the net.
Dr Tan Heok Hui, a fish expert from the Lee Kong Chian Natural History Museum, told The Straits Times that some sharks need to move in order to respire. "Blacktip reef sharks are one of those that need to move constantly," he said.
"From the photo, (the dead sharks) all appear to be of the same cohort as they are all around the same size. Some could even be siblings," he said.
The sharks that were found dead are likely to have been juveniles.
Rene Ong also posted more info and photos on her Naturely Curious facebook page.
A routine intertidal trip turned into a nightmare. Found 3 driftnets at the lagoon, with 13 dead juvenile Black-tipped Reef Sharks, and many other fishes and crabs.
Driftnet kills indiscriminately. Any animal that encounters the net, easily gets entangled, and usually the animal faces a slow death (strangled). In addition, the net also damages the corals and the marine habitat.
It is ok to fish, but do fish responsibly, and there are more sustainable way of fishing.
When we were about to remove the net, the guys who placed the net turned up.
Thankfully the guys were apologetic and regretted the killing of the shark. They also agreed to let the Lee Kong Chian Natural History Museum have the sharks and also the release of the crabs that could not be eaten.
Together with their help we disentangled the crabs, and released them back to the sea. However, there was nothing we could do for the 2 Blue-spotted Fantail Rays, 2 Scorpionfish...and the fishes that were already rotting away... It took us hours to disentangle the crabs as the owner wanted the driftnet back.
At the moment, list of casualty is as follows:
~9 Flower crabs
~7 Swimming Crabs
2 Moon crabs (dead)
14 Red Egg Crabs (released)
5 Mosaic Crabs (released)
5 Hairy Crabs (released)
2 Stone crabs? (released)
1 Spoon-pincer crab (released)
3 Scorpionfish (1released, 2 dead)
1 juvenile catfish (dead)
2 stingrays (dead)
I spider conch (released)
1 Goat fish (dead)
2 Mullet (dead)
X Green Chromide (dead)
X Rabbitfishes (dead)
X Filefishes (dead)
13 juvenile Black-tipped Reef Shark (dead)
...some more fishes...don't know the ID...
13 young sharks found dead in fishing nets at Lazarus Island
Audrey Tan Straits Times 17 Aug 15;
Thirteen juvenile blacktip reef sharks were found dead yesterday in three fishing nets at Lazarus Island, south of Singapore.
More than 30 crabs of various species, some fish and a blue-spotted ray were also found in the gillnets. Several crabs were able to survive after they were disentangled and released by those who found them.
Marine enthusiast Rene Ong, who discovered the casualties, said she was out on a regular intertidal trip when she saw the nets.
They had apparently been laid out overnight by someone who had booked a chalet on St John's Island, which is connected to Lazarus Island by a link bridge.
"When I tried to remove the nets, the guys who placed them there came back. They were apologetic about the kill, but the damage was done," said Ms Ong, who spent about four hours disentangling the live crabs from the nets. Joining her in her efforts were staff and a student from the National University of Singapore (NUS).
She added: "They wanted the nets back, so I could not just cut the nets and release the animals. Thankfully, they agreed to let me have the sharks, and to release any catch that they couldn't eat."
The shark carcasses are being stored in a freezer at the St John's Island Marine Laboratory - part of the NUS Tropical Marine Science Institute. They will be passed to the Lee Kong Chian Natural History Museum for analysis.
Dr Tan Heok Hui, a fish expert from the museum, told The Straits Times that some sharks need to move in order to breathe. "Blacktip reef sharks are one of those that need to move constantly," he said.
"From the photo, (the dead sharks) all appear to be of the same cohort, as they are all around the same size. Some could even be siblings," he noted.
The find, although unfortunate, shows that Singapore's waters are thriving with marine life.
Mr Stephen Beng from the Marine Conservation Group of the Nature Society (Singapore) said the presence of apex predators, such as sharks, is a good indicator of a healthy reef.
He said that, since he first started diving here more than 25 years ago, blacktip reef sharks and bottom-dwelling bamboo sharks have been sighted at Singapore's reefs.
He noted that, now, with a sanctuary in the form of the Sisters' Islands Marine Park, their populations are expected to grow.
Added Mr Beng, who runs the Sea Hounds dive centre: "Gillnetting on shallow reef flats not only wipes out fish, but also physically damages the reefs. The relevant agencies should regulate recreational fishermen to ensure that they do not damage our reefs.
"While our Government tries its best to balance development with environmental sustainability, we can do our part by... educating fishermen about practices that put pressure on our limited reef resources."
Rene Ong posted more photos about what happened to the sharks on her Naturely Curious facebook page.
Update on the 13 juvenile Black-tipped Reef Sharks: The sharks are brought to the Lee Kong Chian Natural History Museum where they are photographed, measured and sampled for DNA analysis individually. We also took the opportunity to check the guts of the sharks. The guts and the contents will tell us what they feed on. The sharks are then preserved. So they are forever immortalized. A big thank you to the museum staff for all the help rendered.
|Thawing the sharks.|
|Measuring the shark.|
|For DNA presevation in the cryo collection.|
|Taking DNA samples.|
|Injecting formalin into the shark to preserve it.|
This was also reported in the Singapore Biodiversity Records: Chim Chee Kong, Lee Yen-ling, Samantha Tong, Teresa Tay & Rene Ong. 16 October 2015. Blacktip reef sharks caught in trammel nets at Lazarus Island. Singapore Biodiversity Records 2015: 158-159