Saturday, February 28, 2009

Help needed for Horseshoe Crab Population & Distribution Survey

The Nature Society (Singapore) Horseshoe Crab Rescue team is looking for help for a Population & Distribution Survey on 8 March 2009 from 2 pm to 6.30 pm. If interested, please contact Dr Hsu Chia Chi.

This island-wide survey aims to establish an estimate of the population and distribution of the two species of Horseshoe Crabs (HSCs) found in Singapore, namely the Mangrove Horseshoe Crab (Carcinscorpius rotundicauda) and Coastal Horseshoe Crab (Tachypleus gigas).

Sectors & Teams
Singapore will be divided into four sectors namely: 1. North-West, 2. North-East, 3. South-East and 4. South-West. Each sector will have a Sector Leader. Survey areas within each sector have been identified and each will have an Area Leader. Depending on the size of the survey area, one or more teams might be assigned. Each survey team comprises four to six volunteers led by a Qualified HSC R&Rer (Team Leader), with an assigned recorder while participants become searchers-cum-measurers.

Survey Areas
The areas we will like to conduct HSC P&D Survey are:

1. Mandai mudflats
2. Lim Chu Kang Jetty- mudflat east of jetty.
3. Sarimbun- beach/mudflat near MOE Jln. Bahtera Adventure Centre.
4. Sembawang Park
5. Lower Seletar Reservoir Dam- mudflat eastern side of estuary.
6. Pasir Ris Park- mudflat east of S. Tampines.
7. Changi Point Ferry terminal- estuary.
8. S. Pandan- estuary beyond dam.

Please state your preference, if any, in your response.

Survey Methods & Search Techniques
Two methods will be employed 1) Transect search to depletion in areas where HSC density is expected to be high and/or 2) Exploratory search in all possible HSC habitats. Search technique is based on HSC sighting and the gentle probing (NOT ploughing) of substrate with gardening forks as well as the careful digging up of buried HSC. Area/Team Leaders will conduct on-site briefing on details such as the exact protocol, instructions and data recording.

Survey of Fishermen
In addition, there will be a survey-cum-conservation education of fishermen by younger members/primary school students. Using a survey-cum-conservation education questionnaire as well as photos of both HSC species, free and entrapped, they will approach local and recreational fishermen at boat mooring sites and popular fishing areas around Singapore.

Attire & Equipment
Recommended: Comfortable outdoor clothes (short or long sleeved tops; shorts or trousers), hat, sun block, old sports shoes/boots/booties that can get wet (NO exposed footwear such as sandals, crocs or slippers), drinking water, plastic bag (for collecting litter from survey sites), small gardening fork/rake (to probe for buried HSC) and 12-inch ruler.

Optional: Insect repellent, gloves or plastic bread wrappers to protect your hands, poncho (survey will be adjourned if there is bad weather), a change of clothes and extra foot wear (washing facilities may not be available at all sites), gardening cutters (to rescue Horseshoe Crabs entrapped in nets), binoculars, camera, note book and pen.

Meet at 2 pm at your assigned meeting point. You may have to walk some distance to your actual survey area. The search proper will be from 4 pm to 6 pm, with the lowest tide at 5 pm.

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