Khalid Bin Othman

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

Project: Distribution and autecology of introduced Gunther’s Frog (Hylarana guentheri)

The native distribution of the Gunther’s frog extends from southern China to central Vietnam including Hong Kong, Macau and Taiwan. Recently, there have been confirmed visual sightings of this species in multiple localities across Singapore. Yet, little remains known of the true extent of their distribution across the island and its ecological impact here. Therefore, this project aims to investigate the distribution and biology of the Gunther’s frog in Singapore. Comparisons with the diets of selected native anuran species will also be made to inform of any dietary overlap and the possibility of interspecific competition. With a clearer understanding of the ecology of this species here in Singapore, these findings may then be used to assess its potential impact as an invasive species and subsequent management strategies that may need to be taken.

Song Shuang

Supervisor: Dr. Darren Yeo Chong Jinn & Dr. Simon Mitrovic (University of Technology, Sydney)

Project: Investigating the allelopathic effects of macrophytes on cyanobacteria

In Singapore, to minimize the occurrence of toxic algal blooms in reservoirs, introduction of macrophytes has been suggested as a form of restoration to shift the stable state of reservoirs from phytoplankton dominated state to macrophyte dominated state. Emergent and submerged macrophytes can potentially inhibit the growth of cyanobacteria by secreting allelochemicals. The first phase of my project aims to investigate the inhibiting effects of allelochemicals of eight aquatic plants species. In particular, this study focuses on the sensitivity of a common bloom forming toxic cyanobacteria, Microcystis aeruginosa, to the allelochemicals produced by the eight species. In the second phase, the two species that produce the most allelochemicals that inhibit the growth of Microcystis aeruginosa will be further studied to evaluate the potential effects of global warming on the effectiveness of the allelochemicals. The results of this project may be used to support the collaborative Pandan Restoration Project between NUS and PUB.

Tan Chun Qi Regina

Supervisors: Dr. Darren Yeo Chong Jinn

Project: Distribution and population structure of an alien freshwater crayfish in Singapore and its potential interaction with a freshwater crab

Believed to be introduced via the aquarium trade, the Australian red-clawed crayfish (C. quadricarinatus) is now widely established in Singapore’s freshwater habitats. Despite its establishment, little is known about the population structure of C. quadricarinatus in Singapore. Also, there is concern that the increase in the distribution of feral C. quadricarinatus populations may pose as a threat to native freshwater species that seek refuge in forested streams. This study thus aims to 1) compare the population structure of C. quadricarinatus between Singapore’s reservoirs and forest streams to predict its potential range expansion; and 2) access the potential interactions between C. quadricarinatus and the native lowland freshwater crab (Parathelphusa maculata). The latter will be investigated through comparing their responses when faced with increased temperature stress in light of climatic warming. The invasion risk of C. quadricarinatus as well as P. maculata’s vulnerability to biological invasions in Singapore can thus be evaluated.

Ow Mun Wai Andre

Supervisors: Dr. Darren Yeo Chong Jinn

Project: Community structure and trophic ecology in Bishan-Ang Mo Kio Park Waterway

As part of the Active Beautiful Clean (ABC) Waters programme by PUB, the upper section of the Kallang River at Bishan-Ang Mo Kio Park was converted into a naturalised river. As there has been no extensive study on the environment since it was naturalised, little is known about the community there. Thus, in order to aid management efforts and to get a better understanding of the river community, this study aims to look at (1) the current fish biodiversity in the river; (2) the movement dynamics of the fish community; (3) explore the trophic relationships and (4) the community structure in the naturalised river.

Wong Qi Yun Melissa

Supervisors: Dr. Hugh Tan Tiang Wah & Dr. Darren Yeo Chong Jinn

Project: Spread of Clidemia hirta in Singapore’s forests

Clidemia hirta, a plant commonly known as Hairy Clidemia, is one of the world’s top 100 most invasive species. Native to South America, C. hirta has spread to Singapore. In 2003, Teo et al. concluded that Singapore’s forest fragments are resistant towards invasion by non-native plant species such as C. hirta. This project is a follow-up to Teo et al. (2003), particularly on the invasive status of C. hirta on Singapore’s forests. Seven different sites in Central Catchment Nature Reserve and Bukit Timah Nature Reserve will be surveyed using the adaptive cluster sampling method. The objectives of this study are: (1) to monitor the extent of spread of C. hirta in Singapore forests, as well as the resistance of Singapore forests towards this species, (2) to compare the results obtained with similar data collected by Teo et al. (2003), and (3) to test the feasibility and efficiency of a new monitoring method (adaptive cluster sampling) on C. hirta.

Movin Nyanasengeran

Supervisor: Dr. Darren Yeo Chong Jinn

Project: Investigating freshwater communities in forest pools and streams in Singapore

The freshwater habitats of Singapore’s forests generally fall into two main types: (1) the more ubiquitous, shallow, flowing (lotic) streams, and (2) the comparatively rarer, still-water (lentic) pools – characterised by greater depth, width and lower flow velocity. Local studies have chiefly focused on streams, elucidating aspects of local stream ecology. However, the specific ecology of forest pools has been largely neglected despite these habitats/microhabitats often being focal points for sampling. My study has the following objectives 1) ascertain if forest pool communities and physico-chemical parameters differ from those of stream sections 2) identify the chief habitat characteristics in forest pools that help explain the distribution of the species within. Answers to the above queries will help provide preliminary data and better understanding that could serve as a springboard for further investigation, or to inform management/policy, particularly the potential conservation or even restoration/enhancement of such habitats as ‘refugia’ for native freshwater taxa during periods of drought or low-water conditions.

Lee Juin Bin

Supervisor: Dr. Darren Yeo Chong Jinn

Project: Morphological variation and autecology of Amphilophus citrinellus in reservoirs and canals of Singapore

Amphilophus citrinellus is the most abundant fish species in Singapore’s urban ponds and it is one of the most successful non-native cichlid species in Singapore. However the reasons for its success in Singapore have yet to be established. As such, this study would investigate the variation of A. citrinellus morphology across different freshwater habitats in Singapore and from its home range in Nicaragua. The changes in morphology would then be investigated for co-variation with autecological factors such as diet and colour morphs which may provide a hint to the reasons behind the success of A. citrinellus in Singapore. Findings from this research could then be applied to other freshwater fish invasions to predict if other freshwater fish species would be able to establish themselves in Singapore’s urban water bodies.​

Yeo Soon Boon Shayne

Supervisor: Dr. Darren Yeo Chong Jinn

Project: Effects of invertivore fish diversity on ecosystem functioning and its stability against environmental stressors

In the highly urbanised Singapore, many natural forest streams are being cleared as forests make way for urban developments. These forest streams are often the last few remaining natural habitats for native forest stream fishes and hence threatened by habitat loss. My study aims to understand how the diversity of local forest stream fishes affects ecosystem functioning (BEF) by looking at functional processes such as feeding and excretion rate. The fishes will be subjected to different diversity treatments based on their feeding guild. Anthropogenic stressors such eutrophication will also be simulated to understand whether diversity affects their tolerance to withstand these stressors. Findings from this study could potentially aid biodiversity conservation efforts and management of the environment. Since a variety of species used in this study are also found in aquarium fish trade, results from this research could also improve aquacultural practices involving these fishes.