Habitat adaptations of ocypodid crabs in coastal marine ecosystems

Project Number
RI 8/10 SL

Project Duration
February 2011 - March 2017

Status
In-Progress (Extended)

Abstract
Global biodiversity has been most seriously threatened by modification, fragmentation and loss of natural habitats. More than 70% of natural habitats have been estimated to have been exploited to complete loss by man. While it is recognized that habitat loss is an important threat in the marine environment. Unfortunately, most of the focus of science and conservation has been on terrestrial environments. Coastal marine ecosystems provide many important services to man such as nutrient cycling, food production, provisions of habitat/refugis, disturbance regulation, natural barriers to erosion, control of water quality and nursery grounds. The global value of such services is estimated to be 10 times that of any terrestrial ecosystems. Predictably, habitat loss is particularly severe in coastal marine ecosystems where human activities have been historically concentrated. Coastal zones occupy less than 15% of the earth's land surface; yet they accommodate more than 60% of the world's population. By 2025, it is estimated that 75% of the world's population will reside in coastal areas. Hence, there is an urgent need for conservation and restoration of marine coastal habitats. We propose to study the adaptations of ocypodid crabs to the habitats in which they live so that we better understand how changes in their habitat may affect species abundances and distributions. Ocypodid crabs (fiddler crabs, ghost crabs, soldier crabs, sand bubblers, etc.) are ubiquitous macrofauna commonly found in coastal habitats. They usually occur in sizeable numbers, respond well to handling and are relatively easy to collect. hence, they are ideal study organisms. The knowledge gained will be potentially useful for biodiversity and population recovery of species 'lost' due to habitat disturbance are important. Substantial research work has been carried out in my laboratory on ocypodid crabs in the past 12 years. Aspects studied to-date included population distribution and abundance of three species ocypodids (two fiddler crabs and one ghost crabs), morphological and behavioural adaptations of the local species of two species of Australian fiddler crabs, as well as the use of our local species of ghost crab as an environmental bioindicator. Results of research in progress locally have shown that distribution and abundance of these important macrofauna are linked closely to habitat characterictics; e.g. adaptations in mouthpart-setation and burrow structure to sediment particle size. Similar trends were also detected from preliminary findings of ocypodid crabs from Australia, Taiwan and Panama. We also have preliminary data that show great physiological tolerance of ghost crabs to heat stress and environmental disturbance (e.g. human activities and recent oil spill at the east coast beaches of Singapore). Funding is now sought in this present proposal to support further in-depth local studies as well as comparative studies to provide evidence for more global insights and general conclusions. This would lead to a better understanding of the interactions between these important coastal macrofauna and the habitat in which they live with a view of using the information for habitat and biodiversity conservation.

Funding Source
NIE

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