Treatment of Tapis A oil-contaminated sediment by using a dual-stage biodegradation

Malaysian marine environment is vulnerable to oil pollution, especially in the Straits of Malacca (Law et al., 2002). Busy maritime transports, active oil explorations and increases industrial activities are the primary factors that lead to oil pollution in the aquatic environment. When oil intruded into the environment, sediment acts as the final “sink” for the pollutants. Oily sediment may pose long term hazardous effects on a wide spectrum of organisms

Trend of meiobenthos density and composition in Karah Island, South China Sea (Corak Kepadatan dan Komposisi Meiobentos di Pulau Karah, Laut China Selatan)

Meiobenthos in Bidong Archipelago in coastal water of the South China Sea is hypothesised to have a certain trend of distribution particularly in the island ecosystem where it is usually having different type of sea bottom. Nonetheless, since it is located in a tropical area, the trend at the sub-tidal could be less obvious due to absent of clear season. Meiobenthic sampling was carried out in Karah Island, an island in Bidong Archipelago, from the intertidal, towards the sub-tidal zone covering the coral and non-coral area to see the trend in the density and composition. A transparent hand core was used to collect benthos samples. Nematoda and harpacticoid copepods dominated the intertidal and sub-tidal zone respectively. Harpacticoid copepods were higher in density in the non-coral sediment than the coral area. This could be due to the high content of silt and clay in the coral area (2.98% of silt and clay). The 2-dimension MDS analysis on the density data indicated the highest degree of scattering and an over-lapping condition for those intertidal and sub-tidal samples respectively. ANOSIM result showed that the degree of similarity was lower at the intertidal (70%) than the sub-tidal (reaching 90%) in the first sampling before both became no significant different in the second sampling. It could indicate the stable condition in the subtidal than the intertidal ecosystem. The comparatively low density of meiobenthos could indicate their response towards the environmental condition in the area which will only be confirmed by long term ecological study

Spatial variability of soil nutrients in Punta Fort William, Greenwich Island, maritime Antarctic

This study aims to report baseline soil nutrients, specifically the organic carbon, nitrogen and phosphorus profile, in soil samples collected from Punta Fort William on Greenwich Island in maritime Antarctic. Samples were collected along two transect lines during the early summer of 2008. Ward’s method of hierarchical agglomerative clustering was employed to group the sampling points based on their physico-chemical properties. In this context, the soil samples can be grouped into three major clusters: (1) Samples with intensive biological activities, (2) samples from the area recently exposed by glacial retreat and (3) samples from barren and dried areas. Nutrient contents in Punta Fort William are driven by the intensity of biological activities as well as melt water from the Quito glacier

Inception Report on Development of A Refugium Management Plan for the Mud Spiny Lobster (Panulirus polyphagus).

This report is under the SEAFDEC/UNEP/GEF Project on “Establishment and Operation of a Regional System of Fisheries Refugia in the South China Sea and Gulf of Thailand”The mud spiny lobster (Panulirus polyphagus) is one of the favourites seafood exported from Malaysia. There are limited studies on the mud spiny lobster by the local scientific community as compared to the rock lobster (Jasus edwardsii) and common spiny lobster (Panulirus vulgaris). Although there are relatively less studies on the mud spiny lobster in this region, the Panulirus polyphagus is the predominant lobster reported in the east coast of the Peninsular Malaysia, from Kelantan in the North, down to Johor in the South (Alias et al., 2000). Noor Hanis and Siow (2019) reported the landing trend of this species begin showing a declining trend since early 2010s’, probably associated with the harvesting pressure. The declining landing trend suggested the needs to protect this spiny lobster to be protected to sustain the species in the area.UNEP/GE

Toward Sustainable Environmental Quality : Priority Research Questions for Asia

Environmental and human health challenges are pronounced in Asia, an exceptionally diverse and complex region where influences of global megatrends are extensive and numerous stresses to environmental quality exist. Identifying priorities necessary to engage grand challenges can be facilitated through horizon scanning exercises, and to this end we identified and examined 23 priority research questions needed to advance toward more sustainable environmental quality in Asia, as part of the Global Horizon Scanning Project. Advances in environmental toxicology, environmental chemistry, biological monitoring, and risk-assessment methodologies are necessary to address the adverse impacts of environmental stressors on ecosystem services and biodiversity, with Asia being home to numerous biodiversity hotspots. Intersections of the food–energy–water nexus are profound in Asia; innovative and aggressive technologies are necessary to provide clean water, ensure food safety, and stimulate energy efficiency, while improving ecological integrity and addressing legacy and emerging threats to public health and the environment, particularly with increased aquaculture production. Asia is the largest chemical-producing continent globally. Accordingly, sustainable and green chemistry and engineering present decided opportunities to stimulate innovation and realize a number of the United Nations Sustainable Development Goals. Engaging the priority research questions identified herein will require transdisciplinary coordination through existing and nontraditional partnerships within and among countries and sectors. Answering these questions will not be easy but is necessary to achieve more sustainable environmental quality in Asia. Environ Toxicol Chem 2020;39:1485–1505

Nutrient enrichment in alginate bead for enhancement of cell growth and ammonium removal by alginate immobilized Nannochloropsis sp.

Microalgae have been immobilized in alginate matrixes for the ease of harvesting of the microalgae. However, not all microalgae thrive when immobilized. Immobilized cells are sensitive to the micro-environment in alginate matrixes. Hence, this study aims to improve the growth of immobilized cells and also ammoniacal-nitrogen (NH4 +-N) removal by adding growth medium in alginate beads during the immobilization process. Different strength of the Guillard’s f/2 medium (0%, 30%, 50%, and 100%) was enriched in alginate beads inoculated with Nannochloropsis sp. The immobilized cells were then cultivated in seawater with 1000 µM NH4 +-N as the sole nitrogen source. The growth and NH4 +-N uptake by immobilized cells enriched with different strength of f/2 medium were compared. There were no significant differences on specific growth rate and specific uptake rate of immobilized cells after nutrient enrichment in alginate beads. However, maximum cells attained and maximum NH4 +-N removed increased when strength of f/2 medium enriched in alginate beads was increased. Significantly higher maximum cells attained and maximum NH4 +-N removal were found in immobilized cells enriched with half strength of f/2 medium than those without nutrient enrichment. The present study demonstrated that nutrient enriched in alginate beads can be used by immobilized cells, and subsequently improves the performance of immobilized cells in marine water treatment and production of microalgal biomass simultaneously

Influence of monsoon on the distribution of organic carbon in inner continental shelf core sediments, South China Sea, Malaysia

Three short sediment cores (12-32 cm) from South China Sea off Southern Terengganu were collected during May (post-Northeast monsoon) and September (pre-Northeast monsoon) 2007. The concentration of total organic carbon (TOC) obtained ranged from 0.41-2.23 and 0.38-2.31% during post and pre-monsoon, respectively. TOC concentration was found to decrease with depth and distance from the coast and river mouth. In particular, station with close proximity to the coast exhibits most pronounced variation of TOC with depth. Besides spatial variation, it is noted that the seasonal variations also considerably affect the distribution and concentrations of TOC, where both near and offshore sampling stations showed significant variations in TOC content during May and September sampling. These findings suggest the importance of terrestrial organic carbon flux, physical mixing and seasonal variations in regulating the concentration and distribution of the organic carbon in the study area

Temporal Variation of Bacterial Respiration and Growth Efficiency in Tropical Coastal Waters ▿

We investigated the temporal variation of bacterial production, respiration, and growth efficiency in the tropical coastal waters of Peninsular Malaysia. We selected five stations including two estuaries and three coastal water stations. The temperature was relatively stable (averaging around 29.5°C), whereas salinity was more variable in the estuaries. We also measured dissolved organic carbon and nitrogen (DOC and DON, respectively) concentrations. DOC generally ranged from 100 to 900 μM, whereas DON ranged from 0 to 32 μM. Bacterial respiration ranged from 0.5 to 3.2 μM O2 h−1, whereas bacterial production ranged from 0.05 to 0.51 μM C h−1. Bacterial growth efficiency was calculated as bacterial production/(bacterial production + respiration), and ranged from 0.02 to 0.40. Multiple correlation analyses revealed that bacterial production was dependent upon primary production (r2 = 0.169, df = 31, and P < 0.02) whereas bacterial respiration was dependent upon both substrate quality (i.e., DOC/DON ratio) (r2 = 0.137, df = 32, and P = 0.03) and temperature (r2 = 0.113, df = 36, and P = 0.04). Substrate quality was the most important factor (r2 = 0.119, df = 33, and P = 0.04) for the regulation of bacterial growth efficiency. Using bacterial growth efficiency values, the average bacterial carbon demand calculated was from 5.30 to 11.28 μM C h−1. When the bacterial carbon demand was compared with primary productivity, we found that net heterotrophy was established at only two stations. The ratio of bacterial carbon demand to net primary production correlated significantly with bacterial growth efficiency (r2 = 0.341, df = 35, and P < 0.001). From nonlinear regression analysis, we found that net heterotrophy was established when bacterial growth efficiency was <0.08. Our study showed the extent of net heterotrophy in these waters and illustrated the importance of heterotrophic microbial processes in coastal aquatic food webs

Feasibility of Marine Microalgae Immobilization in Alginate Bead for Marine Water Treatment: Bead Stability, Cell Growth, and Ammonia Removal

Sodium alginate is the most commonly used polymer matrix in microalgae immobilization for water treatment. However, the susceptibility of alginate matrixes to cation chelating agents and antigelling cation limits the use of alginates in estuarine and marine systems. Hence, the present study aims to investigate the stability of alginate bead in marine water and the feasibility of microalgae to grow when immobilized in alginate bead for marine water treatment. Different concentrations of alginate and hardening cation calcium were used to formulate beads. The beads were incubated in Guillard’s f/2 medium and shaken vigorously by using orbital shaker for 15 days. The results indicated that bead stability was enhanced by increasing alginate and CaCl2 concentrations. Subsequently, the marine microalga, Nannochloropsis sp., was immobilized in calcium alginate bead. The growth and ammoniacal-nitrogen (NH4+-N) uptake by immobilized cell were compared with free cell culture in f/2 medium. Specific growth rate of immobilized cell (0.063 hr−1) was significantly higher than free cell (0.027 hr−1). There was no significant difference on specific uptake rate of free cell and immobilized cell; but immobilized cell removed significantly more NH4+-N (82.2%) than free cell (47.3%) culture at the end of the experiment. The present study demonstrated the potential use of alginate immobilization technique in marine microalgae culture and water treatment simultaneously