Prehistoric critters' hot, sweaty helpers

Volunteers brave mud and sun to save local horseshoe crabs

Trudging through warm mud and getting stuck in it while you sweat bullets on a hot and humid afternoon is not everyone's cup of tea.

But for the 86 volunteers at the Mandai mudflats, the discomfort was a small price to pay.

They were there to participate in the Nature Society (Singapore)'s Horseshoe Crab Research and Rescue Programme, which saves the horseshoe crabs that have been caught in nets and collects data for conservation purposes.

"I wore normal shoes to the mudflats and getting stuck knee-deep was an interesting new experience," said Anglo-Chinese Junior College student Brenda Lee, 17.

"It was also frustrating and some of our friends lost their shoes. But rescuing horseshoe crabs is important as they are a vital part of our ecosystem that many of us neglect."

Volunteers with the Nature Society (Singapore) examining the Mandai mudflats for horseshoe crabs, as part of the organisation’s Horseshoe Crab Research and Rescue Programme. ST PHOTO: LIM YAOHUI

To rescue horseshoe crabs entangled in nets or crab pots, volunteers are given scissors and cutters to cut them loose. Volunteers also study the crabs they spot and record data such as size, gender and population density on their mobile phones.


Some of our friends lost their shoes. But rescuing horseshoe crabs is important as they are a vital part of our ecosystem that many of us neglect. 

BRENDA LEE, a student, on her experience volunteering at the Mandai mudflats.

No prior experience is needed, only a willingness to go the extra mile for an animal that many hardly give a thought to. Nor is there an age restriction. Children as young as three have participated - with parental supervision.

Another objective of the programme is public outreach, to raise awareness of the habitats' existence and the importance of the Mandai mudflats to neighbouring areas like Sungei Buloh.

Horseshoe crabs have been around since before the dinosaur era. Despite their name, they are not crabs and only superficially resemble crustaceans. Instead, they belong to a separate sub-phylum, Chelicerata. They are closely related to arachnids - a group that includes spiders and scorpions.

There are four species of horseshoe crabs in the world, three of which are found in Asia. Two - the mangrove horseshoe crab and the coastal horseshoe crab - are found in Singapore, but not the Chinese horseshoe crab.

Ms Hasmah Dadlani, 24, a volunteer from Tampines West CC’s Eco Interest Group, helping to pull eight-year-old Lorraine Goh from the mud. Good, tight shoes are necessary for walking in the mudflats. ST PHOTO: LIM YAOHUI

"Here, there is no real status given in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, so we have no idea whether they are fine or not," said Ms J. Vanitha, 35, a teacher and current leader of the Nature Society's programme.

The IUCN Red List is recognised as the most comprehensive assessment of the conservation status of biological species.

In the United States, the Atlantic horseshoe crab is harvested for its blood, which is used in the pharmaceutical industry. It is considered vulnerable to extinction.

Scientists in Singapore consider the mangrove horseshoe crab to be vulnerable to extinction and the coastal horseshoe crab to be endangered, owing to irresponsible fishing and habitat loss.

A female horseshoe crab being held up by a guide as volunteers are briefed on the task at hand. ST PHOTO: LIM YAOHUI

The Mandai mudflats are the only known place these two species gather in such big numbers.

There are mangroves in Pulau Ubin and offshore islands, said Ms Vanitha, but mangrove patches with long, large mudflats are not easily found on mainland Singapore outside the Sungei Buloh Wetland Reserves.

About 400 to 600 horseshoe crabs are counted during each session.

The data is used for research purposes and four scientific papers have been published based on the findings so far.

Data is also shared at local and international conferences, such as the IUCN World Conservation Congress held in Honolulu last September, which Ms Vanitha attended.

Ray Hirano (far left), 11, getting up close and personal with a horseshoe crab while volunteers are being briefed.ST PHOTO: LIM YAOHUI

Volunteers can sign up for the sessions through the Nature Society's newsletter or website, or through schools and corporations. The sessions are open to the public.

However, registration for the next session on Feb 11 is full. For more information, go to https://www.nss.org.sg.

A version of this article appeared in the print edition of The Straits Times on January 16, 2017, with the headline 'Prehistoric critters' hot, sweaty helpers'. Print Edition | Subscribe