The Malaysian Government has set a target of achieving 20% penetration of Renewable Energy (RE) in the energy mix spectrum by 2025. In order to get closer to the target, Ocean Thermal Energy Conversion (OTEC) aligned with solar PV, biogas and biomass energy sources must be evaluated and comprehended. Hybrid OTEC systems consisting of energy and water production are currently under research and validation. Therefore, for the construction of a commercial OTEC plant, 1 MW or 2.5 MW, the choice of a strategic location or potential site is vital. In this paper, oceanographic data such as seawater temperature, depth, salinity and dissolved oxygen obtained from the Japan Oceanographic Data Center (JODC) for Semporna, Tawau, Kudat, Pulau Layang-Layang and Pulau Kalumpang in Sabah, Malaysia, are reported. The RE available from the Exclusive Economic Zone (EEZ) on the coast of Sabah was estimated based on the JODC data obtained. There were no remarkable differences in temperatures between the five sites, which were reported as approximately 27 °C at the surface and 7 °C at depths below 600 m. The surface salinities below 100 m at those sites were slightly lower than the deeper waters, where the salinity increased up to approximately 34.5 PSU. Dissolved oxygen data from the Pulau Kalumpang site showed a slight increment to approximately 4.7 mL/L at depth intervals below 50 m, before declining steadily to approximately 1.7 mL/L along with the depth. The temperature-salinity profiles of the Malaysian sites were congruent with those of Palau, Kumejima and Okinawa, but not with that of Fiji, where the salinity profile showed a distinct variation at the relative depth (below 200 m). Estimates of RE using two different methods were used to prove the potential of OTEC in Malaysia.

A population genetics study was carried out on the Southern River terrapin (Batagur affinis) from four places in Peninsular Malaysia: Pasir Gajah, Kemaman (KE), Terengganu; Bukit Pinang (BP), Kedah; Bota Kanan (BK), Perak; and Bukit Paloh, Kuala Berang (KB), Terengganu. The goal of this study is to identify genetic differences in two subspecies of B. affinis in Malaysia. No previous reports were available on the genetic diversity, phylogenetic relationships and matrilineal hereditary structure of these terrapin populations in Malaysia. The sequencing identified 46 single nucleotide polymorphisms that defined six mitochondrial haplotypes in the Southern River terrapins. Tajima’s D test and Fu’s Fs neutrality tests were performed to evaluate the signatures of recent historical demographic events. Based on the tests, the B. affinis edwardmolli was newly subspecies identified in the west coast–northern region of Kedah state. In addition, the B. affinis edwardmolli in Bukit Paloh, Kuala Berang (KB), Terengganu (Population 4), was shown to have a single maternal lineage compared to other populations. Low genetic diversity, but significant genetic differences, were detected among the studied Southern River terrapin populations.

Benthic diatoms are important components of marine shallow-water habitats that may affect primary production, stabilize sediment, and produce extracellular polymeric substances. Benthic diatoms are useful for estimating the trophic status of marine ecosystems. In this study, we investigated the diversity and abundance of benthic diatoms to integrate these data with the physicochemical characteristics of shallow coastal areas in Negeri Sembilan. A total of 39 species of epipelic diatoms were extracted by removing organic matter from sediments that were dominated by pennate diatoms. Results showed that Diploneis crabro, Eunotogramma laevis, Actinoptychus sp., and Cocconeisplacentula were the important species in the area. The abundance varied between 1.85 × 10³ and 3.43 × 10³ cells/g, and the diversity index fluctuated between 2.13 and 2.58. The abundance had significant positive correlations with seawater surface temperature (SST) but had negative correlations with pH and NH₃. The diversity on the other end was positively correlated with SST but negatively correlated with total suspended solids and SiO₂. Principal component analysis (PCA) demonstrated that the abundance of D_. crabro, E. laevis, and Actinoptychus sp_. can be attributed to high levels of NO_2⁻, NH₃, and total dissolved solids. PCA also showed positive correlations of C_. placentula with NO₃⁻and SiO₂ but negative ones with PO₄³⁻ and pH. The epipelic diatom community showed high diversity with high variations throughout the study area.

Terminalia catappa leaf, also known as Ketapang leaf, is well known for its medicinal properties and long history of use in aquaculture. Studies on the effects of leaf extracts on fish productivity are scarce. This study performed a time-series observation of ground young and mature T. catapppa leaves on tropical phytoplankton productivity. The young and mature leaves were prepared as fine powder separately. For the time-series experiment, 10 grams of each ground leaf were added to 10 L of lake water containing phytoplankton and incubated at room temperature with ambient illumination. The chlorophyll a saturation optical density was quantified on alternate days using a spectrophotometer and the data were analysed using Origin 6.0 Software. On Day 11, the chlorophyll a percentage had decreased by 73% and 81% in the control and mature leave treatment carboys, respectively. Meanwhile, the sample treated with young leaves of T. catappa showed only a 29% decrease. The results have shown that phytoplankton treated with young T. catappa powder demonstrated a positive but weak correlation (R² = 0.123), represented by the chlorophyll saturations. This study supported the hypothesis that young T. catappa leaves sustained phytoplankton growth.

This article describes the abundance of phytoplankton community structures in Port Dickson, Negeri Sembilan and Pulau Tinggi, Johor during the Southwest and Northeast Monsoons and includes data from 48 selected sampling sites collected between July and December 2023. The seawater samples from 1-meter depth were obtained by using a Niskin water sampler, concentrated in a 50 ml centrifuge tube and immediately preserved with Lugol's iodine solution. The data include phytoplankton density (cell L⁻¹), the total density of phytoplankton in each station, and the total number of genera obtained in every station. Additional data are presented, including chlorophyll-a concentration, as a proxy for biomass and photosynthetic active radiation. This article presents data on 30 genera, including unidentified genera, as well as the percentage of the main community group.

Objectives: Microbial communities in freshwater are pivotal for driving nutrient transformation, bioremediation, and maintaining the health balance of these ecosystems. However, microbial communities in freshwater ecosystems may undergo rapid shifts in composition in response to environmental changes. In some cases, these shifts may signal ecological imbalance. In the tropics like Malaysia, high humidity coupled with high temperatures and seasonal rainfalls creates an even hotter and highly variable environmental conditions that promote microbial proliferation and increase the risk of introducing potentially pathogenic microorganisms from surrounding anthropogenic sources via surface runoff. The current study offers a comprehensive characterisation of bacterial community composition in Malaysian freshwater drinking reservoirs using high throughput 16 S rRNA gene amplicon sequencing. This approach enables bacterial community profiling and supports initial microbial risk assessment in these vital freshwater ecosystems. Data description: State Authorities permitted the collection of water samples from eight freshwater reservoirs within Peninsular Malaysia’s protective zones. The 16 S rRNA gene’s V3-V4 hypervariable region was amplified for next generation sequencing. Raw DNA sequence data in FASTQ format were quality-filtered, adapter-trimmed and processed using a QIIME v1.9.1 based pipeline that integrated standard bioinformatics tools for OTU clustering and taxonomic assignment. Utilising R v3.3.1, statistical analyses and data visualisations were performed on this dataset. Characterising the community structure of bacteria in these important freshwater ecosystems is the first step to working with this dataset.