Goh, Beverly P. L. (Beverly Pi Lee)

In the past year (July 2014 to March 2015), 90 secondary school students participated in an Environmental Science themed Project-Based Learning (PBL) program designed by scientists at the National Institute of Education, Singapore. The authenticity of the PBL program was enhanced by partnership with NParks' Coastal Biomonitoring program. A total of 22 school teachers were also involved as facilitators of their students' project work. The strategic partnership of NIE scientists, secondary schools and NParks created a unique experience for students engaging in PBL.

Effects on mortality and settlement of Pocillopora damicornis planula larvae during recovery from low levels of Ni++ were investigated. Results indicated that a nickel concentration of 9 ppm over 12 hr was sufficient to cause 50% mortality in larvae 39.6 hr after removal of the toxicant. Settlement in larvae was more sensitive, showing significantly reduced settlement rates from 9 days into recovery, after exposure to I ppm Ni++ at durations of 12-96 hr. It is recommended that coral planula larvae be utilized more extensively in pollution studies.

Echinoderms have increasingly become subjects of interest as possible biomarkers and bioindicators due to their abundance, ecological relevance and high sensitivity to many contaminants and environmental stressors. The common sea star, Archaster typicus, found along sandy inter-tidal areas in the Southern Islands of Singapore, was utilised in this baseline study to compare the density, physiological, cellular and biochemical responses to the environment at St John’s Island and Pulau Hantu, and to determine if the employed biomarkers could serve as expedient and effective indicators of environmental change. Three field surveys each were conducted at St John’s Island with three-month intervals (September 2020, December 2020 & March 2021) and Pulau Hantu with one-month intervals (January 2021, February 2021 & March 2021). The physiological biomarker tested was the righting behaviour, cellular biomarker involved cellular lysosome response through the neutral red retention time (NRRT) assay, and biochemical assays included the ferric reducing antioxidant power (FRAP) assay and the total glutathione (GLUT) assay. Results showed that righting response and GLUT concentration were the two biomarkers with better predictability of environmental change and pollution, with an increase in response shown with increasing environmental stress. Seasonality, or specifically the monsoon seasons was a dominant environmental stressor.

Previous studies have shown marine bivalves to be suitable bioindicators for heavy metal pollution in the marine environment. In this study, the potential of the Green Mussel, Perna viridis to be a bioindicator of copper and cadmium contamination in the marine environment was explored. The study aimed to develop a toxicity bioassay using P. viridis, and explored if a dose-response relationship between fertilisation in P. viridis and increasing concentrations of copper and cadmium could be established. The effect of copper and cadmium on embryo formation was also examined. Few fertilisation assays involve the use of the P. viridis, a tropical marine bivalve. Rather, a temperate mussel Mytilus sp., is more commonly used. As such, this study is relevant to the Southeast Asian region. Mussel gametes were subjected to increasing concentrations of cadmium and copper over a 24h test period. Following this, the number of unfertilised eggs was counted under a microscope. Data obtained was then arcsine transformed and subjected to one way Analysis of Variance (ANOVA) and Dunnett’s test to determine if a significant dose-response curve could be established. Results indicated significant treatment effects and a degeneration of unfertilised eggs when gametes were subjected to cadmium and copper solutions.

The gametogenic cycle of Platygyra pini was investigated at three sites around Singapore’s southern islands from Mar.2001 to Apr.2002. Equatorial locations, such as Singapore, typically experience moderate annual environmental variation. This has lead to the suggestion that the amplitude of environmental variation at the equator is insuffi cient to provide reliable cues to synchronise reproduction in marine invertebrates. However, distinct and predictable seasonal patterns of sea surface temperature and rainfall occur in Singapore as a result of the Southeast Asian Monsoon system. Platygyra pini had a seasonal pattern of gametogenesis, with maturation of gametes and spawning occurring predominantly in April. A second, smaller peak in reproductive activity occurred in November suggesting that some colonies also spawn at this time. The major spawning for this species followed a period of rising sea surface temperatures and occurred after the period of heaviest rainfall. While a correlation between environmental fluctuations and spawning timing is not proof of a causal link, these data do indicate that the amplitude of change in environmental parameters such as temperature in Singapore is sufficient to provide a seasonal cue for reproduction and spawning synchrony.

Since 2001, Singapore has consistently performed well at the International Biology Olympiads (IBO). A commentary piece is provided by Team Singapore Delegation Leaders in the 2012 – 2015 IBO competitions as well as the President of the 40th and 41st SIBiol Councils on factors that contributed to the Singapore Institute of Biology’s (SIBiol) sustained success in the IBO competition over the last five years.