Experts aim to save one of Singapore's most threatened unique species at Inaugural Roundtable on Freshwater Crab Conservation

NParks, NUS, IUCN, and WRS among agencies collaborating to save endemic crabs,

including Johora singaporensis which is among the 100 most threatened species in the world

The critically endangered Singapore freshwater crab (Johora singaporensis), is among the 100 most threatened species in the world.Found only in Singapore, it grows up to 3cm across the carapace, or the shell, and up to 5cm with the legs stretched out. It performs an important role in the proper functioning of hill streams by helping in nutrient recycling, and is potentially an indicator of pollution and climate change.  PHOTO CREDITS: DANIEL NG (left) and CAI YIXIONG (right)

Johora singaporensis,commonly called the Singapore freshwater crab, is arguably one of the most threatened unique species of Singapore. To discuss ways to develop an overall plan for conservation of this species, expertsconvened in the inaugural Roundtable on Freshwater Crab Conservation which began with a two-day closed-door panel discussion, and  concluded with a public forum on 29 March 2014.

The four organisations involved are National Parks Board (NParks), National University of Singapore (NUS), International Union for Conservation of Nature (IUCN), and Wildlife Reserves Singapore (WRS). The inaugural Roundtable on Freshwater Crab Conservation is funded by the Wildlife Reserves Singapore Conservation Fund.

First discovered and described in 1986, the Singapore freshwater crab(Johora singaporensis) is listed as Critically Endangered in the IUCN Red List of Threatened Species™, and is among the 100 most threatened species in the world. This endemic species, only found in Singapore, grows up to 3cm across the carapace, or the shell, and up to 5cm with the legs stretched out. It performs an important role in the proper functioning of hill streams by helping in nutrient recycling, and is potentially an indicator of pollution and climate change.

“When I discovered and named this species in the 1980s, I had no idea that its future would be a matter of debate and concern some 25 years on,” said Professor Peter Ng of the Department of Biological Sciences at the NUS Faculty of Science.  “It heartens me that so many people are now trying to save this ‘insignificant invertebrate’ from imminent extinction. It would indeed have been a dark tragedy if discovering the species all those years ago was merely a prelude to its extinction. I hope it is not.”

“Crabs such as Johora singaporensis are typically found in hill streams, which is a rare habitat in Singapore to begin with, being restricted to only the central part of the island,” added Assistant Professor Darren Yeo, who is also with the Department of Biological Sciences at the NUS Faculty of Science.

Decade-long monitoring of the populations of Johora singaporensis has revealed that these crabs have an environmental preference for relatively clean and fast-flowing streams in the highlands with a near neutral pH.Presently, the crab is found largely in Bukit Batok, Bukit Gombak and Bukit Timah Nature Reserve. They can persist even in small fragmented habitats under the right conditions. Current conservation efforts include plans to establish a breeding programme, as well as an ongoing two-year research project launched in 2013 by NParks and NUS to study the conditions of the crabs’ existing habitats and possible remedial actions. As conservation efforts gain momentum, the next important milestone is to gather key stakeholders together to improve them.

The Roundtable on Freshwater Crab Conservation brings together key stakeholders involved in conservation of the iconic Johora singaporensis, for consolidation and dissemination of results of ongoing freshwater crab conservation efforts in Singapore. Foreign and local ecologists including researchers from the National University of Singapore and officers from the National Parks Board working on Johora singaporensis, as well as other members from Wildlife Reserves Singapore, Nature Society Singapore, Ministry of Defence, Singapore Land Authority, National Environment Agency, Public Utilities Board, and Urban Redevelopment Authority have all been invited to participate, brainstorm, contribute their unique perspectives, and help moulda future conservation plan for this species.

Dr Lena Chan, Director of National Biodiversity Centre, NParks, said, “NParks is committed to the conservation of our native freshwater organisms, particularly endemic species like the Singapore Freshwater Crab Johora singaporensis, Johnson’s Freshwater Crab Irmengardia johnsoni and Swamp Forest Crab Parathelphusa reticulata. We look forward to our usual amicable multi-agency co-operation which is crucial for the success of this conservation initiative.”

Dr Neil Cumberlidge, Chair of the IUCN SSC Freshwater Crab and Crayfish Specialist Group, and Dr Philip McGowan of the IUCN Species Survival Conservation Planning Sub-Committee will both participate in the Roundtable, adding valuable inputs to the design of the conservation plan. Dr McGowan said, “Effective conservation in today’s world has to balance the needs of species with those of people and their interests. Our approach has evolved to reflect that. The purpose of strategic planning is to understand what is driving the threats to the Singapore freshwater crab and then develop a holistic and realistic way forward that gives this iconic species the best chance of survival. Strategic planning on its own will not save the species, but the understanding and agreement that is part of the planning process, greatly improves its survival prospects.”

Dr Cheng Wen-Haur, Chief Life Sciences Officer, Wildlife Reserves Singapore said, “Wildlife Reserves Singapore is continuously exploring ways we can work with field researchers, and contribute to the ex-situ conservation of Johora singaporensis. A possible method may be to establish a trial breeding project in River Safari for these native crabs, followed by the eventual reintroduction of the species into restored, rehabilitated streams.”

This Roundtable is also indicative of Singapore’s willingness and seriousness regarding the protection of its freshwater biodiversity and the ‘not-so-charismatic’ fauna.