Cho Jia Yi, Tricia

Supervisors: Dr. Darren Yeo Chong Jinn & Dr. Daniel Ng Jia Jun (National Parks Board)

Project: Autecology of the greenhouse frog, Eleutherodactylus planirostris, in Singapore

The greenhouse frog, Eleutherodactylus planirostris, is a small frog species native to Caribbean that was recently found to be established in urban areas in Singapore. The ornamental plant trade has been proposed as the pathway of introduction of this species, with its inconspicuous calls, small adult and egg size allowing it to go unnoticed in potted plants. The species’ adaptability to hot and dry conditions also makes it an effective coloniser and a generalist that can establish across a wide range of urban and natural habitats. The ability of this species to undergo direct development, hatching as fully developed juvenile frogs without the need for an aquatic tadpole stage, further enhances its ability to establish in new locations. In other parts of its introduced range, Eleutherodactylus planirostris is known to impact native communities through its large consumption of invertebrates. Little, however, is known about the species and its status and impacts in Singapore. A study of the diet, habitat, population structure and distribution of E. planirostris in Singapore is therefore an important first step towards understanding its potential impacts on the native ecosystem, and the development of relevant management strategies.

Choo Zheng Jie Marcus

Supervisors: Dr. Darren Yeo Chong Jinn

Project: The potential of odonates as biological control of mosquitoes and other insect pests in urban aquatic environments

Mosquitoes are important vectors for disease in the tropics. Biological control of mosquito populations in Singapore has been attempted through the introduction of non-native (i.e. alien) fishes that are known to be highly invasive (e.g., mosquitofish, guppy). With growing awareness of the threat posed by such invasive alien species, and interest to enhance native urban biodiversity, alternative taxa are being investigated. Odonates, owing to their relatively large size, long developmental time, and sharing of habitats with mosquito larvae, have good potential as a biological resource to curb mosquito populations. Unlike generalist predators such as mosquitofish, some odonate nymphs have been shown to exhibit selective predation preference for mosquito larvae. Furthermore, employing native odonates that are popular and charismatic can at the same time contribute to enhancing native biodiversity in urban areas. To date, however, the actual effectiveness of native odonates as mosquito control agents is not known. Hence, a study to assess the feeding ecology and predation efficiency of odonate nymphs is required.

Nikita Choudhary

Supervisors: Dr. Darren Yeo Chong Jinn & Dr. Maxine Mowe

Project: Investigating the abundance, distribution and impacts of macro- and micro-plastics in urban tropical freshwater habitats with Singapore as a case study

In recent years, plastic pollution has been a growing global environmental concern with potential impacts on biodiversity and human health. However, few research studies have focused on plastic pollution in tropical freshwater systems. This study aims to look at reservoirs and canals of Singapore to 1) identify the most abundant type of plastic pollution (both macro- and micro-plastics); and 2) determine the potential effects of on macroinvertebrates. To achieve this, water and sediment samples will be collected from five freshwater systems—Pandan Reservoir, Marina Reservoir, Bishan-Ang Mo Kio waterway, Ulu-Pandan Canal, and Upper Seletar Reservoir. Samples will then be processed through chemical separation and classified. Recreating the environment in Bishan-Ang Mo Kio waterway, known for its macroinvertebrate diversity, the ex-situ laboratory experiments aim to observe impacts of different concentrations of plastics found in that environment on macroinvertebrates.

Sim Wei Hung Clarence

Supervisor: Dr. Darren Yeo Chong Jinn & Dr. Maxine Mowe

Project: Effects of artificial floating wetlands installation on the aquatic biodiversity and ecology in a tropical granite quarry pond

Pulau Ubin has several abandoned granite quarries that have filled with rainwater and become prominent freshwater habitats on the island. One of these quarry ponds is the site of existing as well as proposed additional artificial floating wetlands (AFWs), primarily constructed to enhance avian diversity. The freshwater biodiversity and ecology of the quarry ponds as well as their responses to the installation of AFWs is not known. While AFWs have been studied extensively in temperate countries, comparatively less research has been done in the tropics. In Singapore for instance, only a handful of studies on the effects of floating and non-floating artificial wetlands reservoirs have been published so far. With the fundamentally different history and characteristics of quarry ponds, there is a need to study the limnology of these unique freshwater habitats, including how the aquatic biodiversity and ecology may be affected by the installation of the AFWs. Thus, my project aims to investigate the potential ecological impacts arising from the installation of artificial floating wetlands in granite quarry ponds. Specifically, the project aims to monitor and compare responses in biotic and abiotic parameters in selected quarry ponds in Pulau Ubin before, during, and after the installation of the artificial floating wetlands in one of the ponds.