Mandai mangrove and mudflat workshop on 31 Aug (Sat). Come for this session and join the people who care about Mandai mangroves. For easier access, here's the full text article on this awesome seagrass done some time ago.
Tiny but mighty: Halophila beccarii on Singapore's northern shores
by Ria Tan, Siti Maryam Yaakub and Andy Dinesh
First appeared in Seagrass-Watch Issue 44 Nov 2011
Considered globally rare, Halophila beccarii is listed as 'Vulnerable' worldwide. According to the IUCN, this seagrass is estimated to occupy less than 2,000 km² with a patchy and fragmented distribution in the Indo-Pacific. It also has a narrow, restricted depth range. The intertidal area where they grow are subject to much human disturbance. Although it is fast-growing and may recover quickly from disturbance, global population trends indicate this species is declining.
In Singapore, this diminutive seagrass is listed as 'Critically Endangered' in the Singapore Red Data Book (2008) due to its limited distribution on Singapore's shores.
Halophila beccarii is easily overlooked. It is tiny, often occurs in small patches, and resembles scum or algae when out of water. In some specimens found in Singapore, Halophila beccarii have a reddish-brown banding pattern resembling stripes on the leaves which has earned it the moniker "tiger seagrass" amongst some seagrass nerds here in Singapore.
sea anemone survey in 2007] and at Chek Jawa, Pulau Ubin [probably first recorded during Joseph Lai's Chek Jawa survey in 2001], with small patches on the northern shore, near the boardwalk's T-shaped extension, and larger patches on the southern shore besides House No. 1.
Andy Dinesh], field trips in Jan-Mar 2011 discovered more about the full extent of vast meadows which lie outside the Sungei Buloh Wetland Reserve proper.
|Photo by Andy Dinesh|
Many egrets were seen resting in deeper water near these meadows at low tide.
Few patches of Halophila beccarii were found along the northern shore between Kranji Nature Trail and the Kranji east shore next to Sungei Mandai Besar. Although this stretch of shore also has mangroves, the trees here form a narrow band and this area is heavily affected by debris, much of which seem to have been dumped from land and did not drift in by sea.
It was interesting to observe that mangrove saplings are often seen in these Halophila beccarii meadows. Stands of regularly spaced Sonneratia alba saplings of similar height are particularly commonly seen in the meadows that grow beyond the shade of large mangrove trees.
Why were these Halophila beccarii meadows only recently observed? Have they been overlooked all this time? Or did the year end monsoon and particularly the heavy rains in Jan 2011 lead to better growth of the seagrass?
We shall have to keep a closer eye on these precious meadows to find out more about them!
More about Halophila beccarii
- The IUCN Red List of Threatened Species http://www.iucnredlist.org/apps/redlist/details/173342/0
- Lee Chengfa Benjamin’s taxo wiki page http://taxo4254.wikispaces.com/Halophila+beccarii
- Wildsingapore wild fact sheet http://www.wildsingapore.com/wildfacts/plants/seagrass/beccarii.htm
Related blog posts
- Beccari the explorer and Singapore
- More Beccari hunting from Kranji, Jul 2013
- Beccari hunting at Mandai mangroves: Success! Jul 2013
- Another side of Mandai mangroves, Jun 2012
- First time to Mandai mangroves! Mar 2011
- Vast meadows of rare seagrasses at Kranji, Feb 2011
- Back to the rare seagrass meadows at Kranji for a closer look, Feb 2011
- Rare seagrass at Kranji Nature Trail, Feb 2011
- Chek Jawa with TeamSeagrass, May 2009
- Are there seagrasses at Kranji Nature Trail?, Jan 2009