The data presented here are related to the research paper entitled "A below-the-present late Holocene relative sea level and the glacial isostatic adjustment during the Holocene in the Malay Peninsula" (Tam et al., 2018) [1]. The diatoms and pollen data are collected from surface sediments of the Merang wetlands, Kuala Terengganu, Malaysia, and are presented as percentages of total diatoms or total land pollen respectively. Ground elevations of the sampling sites are levelled to the national datum and expressed as elevations above or below mean sea level. These diatom and pollen data can be used for indicative meaning calibration of sea-level index points and for the development of diatom-based or pollen-based tidal level transfer functions. These data have been used for calibrating the indicative meanings for sea-level index points in the reconstruction of Holocene sea-level history of the Peninsular Malaysia.
In the last 10 years, the microbial fuel cell (MFC) has been extensively studied worldwide to extract energy from wastewater via electricity generation. More recently, a merged technique of embedding MFC into a constructed wetland (CW) has been developed and appears to be increasingly investigated. The driving force to integrate these two technologies lies in the fact that CWs naturally possess a redox gradient (depending on flow direction and wetland depth), which is required by MFCs as anaerobic anode and aerobic cathode chambers. No doubt, the integration of MFC with a CW will upgrade the CW to allow it to be used for wastewater treatment and, simultaneously, electricity generation, making CWs more sustainable and environmentally friendly. Currently, published work shows that India, China, Ireland, Spain, Germany and Malaysia are involved in the development of this technology although it is in its infant stage and many technical issues are faced on system configuration, operation and maximisation of electricity production. This paper aims to provide an updated review and analysis of the CW-MFC development. Focuses are placed on the experience gained so far from different researchers in the literature and further research directions and proposals are discussed in great detail.
Fusarium genus comprises important saprophytic and phytopathogenic fungi and is widespread in nature. The present study reports the occurrence of Fusarium spp. in soils from two mangrove forests in northern Peninsular Malaysia and analyzed physico-chemical properties of the mangrove soil. Based on TEF-1α sequences, nine Fusarium species were identified: Fusarium solani species complex (FSSC) (n = 77), Fusarium verticillioides (n = 20), Fusarium incarnatum (n = 10), Fusarium proliferatum (n = 7), Fusarium lateritium (n = 4), Fusarium oxysporum (n = 3), Fusarium rigidiuscula (n = 2), Fusarium chlamydosporum (n = 1), and Fusarium camptoceras (n = 1); FSSC isolates were the most prevalent. Phylogenetic analysis of the combined TEF-1α and ITS sequences revealed diverse phylogenetic affinities among the FSSC isolates and potentially new phylogenetic clades of FSSC. Soil analysis showed varied carbon content, pH, soil moisture, and salinity, but not nitrogen content, between sampling locations. Regardless of the physico-chemical properties, various Fusarium species were recovered from the mangrove soils. These were likely saprophytes; however, some were well-known plant pathogens and opportunistic human pathogens. Thus, mangrove soils might serve as inoculum sources for plant and human pathogenic Fusarium species. The present study demonstrates the occurrence of various Fusarium species in the extreme environment of mangrove soil, thereby contributing to the knowledge on species diversity in Fusarium.
Mineral elemental uptake by Colocasia esculenta growing in swamp agroecosystem was studied following 14, 18 or 28 months of field spraying (MAT, months after treatment) with herbicide Gramoxone ® (paraquat). In overall, Al (68226.67 + 24066.56 μg/g dw) was the major element in riverine alluvial swamp soil, followed by micronutrient Fe (22280.00 + 6328.87 μg/g dw).
Concentration of macronutrient K (20733.33 + 7371.82 μg/g dw) was the highest in swamp taro leaf followed by macronutrient Ca (7050.00 + 3767.26 μg/g dw). In overall, the order of importance of the average mineral concentration in swamp taro leaf was K > Ca > Mn > Al > Na > Fe > Zn > Br > Co. However at 14 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Al > Na > Mn > Fe > Zn > Br > Co. At 18 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Mn > Al > Fe > Na > Zn > Br > Co. At 28 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Mn > Fe > Al > Zn > Na > Br > Co. In overall, the average order of importance of mineral elemental uptake or the soil plant transfer coefficient was Mn > K > Na > Zn > Co > Fe > Al; similar with the order at 28 MAT. However, at 14 MAT the order of importance of the soil plant transfer coefficient was different at Mn > K > Na > Co > Zn > Al > Fe.
The common industrial starches are typically derived from cereals (corn, wheat, rice, sorghum), tubers (potato, sweet potato), roots (cassava), and legumes (mung bean, green pea). Sago (Metroxylon sagu Rottb.) starch is perhaps the only example of commercial starch derived from another source, the stem of palm (sago palm). Sago palm has the ability to thrive in the harsh swampy peat environment of certain areas. It is estimated that there are about 2 million ha of natural sago palm forests and about 0.14 million ha of planted sago palm at present, out of a total swamp area of about 20 million ha in Asia and the Pacific Region, most of which are under- or nonutilized. Growing in a suitable environment with organized farming practices, sago palm could have a yield potential of up to 25 tons of starch per hectare per year. Sago starch yield per unit area could be about 3 to 4 times higher than that of rice, corn, or wheat, and about 17 times higher than that of cassava. Compared to the common industrial starches, however, sago starch has been somewhat neglected and relatively less attention has been devoted to the sago palm and its starch. Nevertheless, a number of studies have been published covering various aspects of sago starch such as molecular structure, physicochemical and functional properties, chemical/physical modifications, and quality issues. This article is intended to piece together the accumulated knowledge and highlight some pertinent information related to sago palm and sago starch studies.
Tropical peat swamp forests sequester globally significant stores of carbon in deep layers of waterlogged, anoxic, acidic and nutrient-depleted peat. The roles of microbes in supporting these forests through the formation of peat, carbon sequestration and nutrient cycling are virtually unknown. This study investigated physicochemical peat properties and microbial diversity between three dominant tree species: Shorea uliginosa (Dipterocarpaceae), Koompassia malaccensis (legumes associated with nitrogen-fixing bacteria), Eleiodoxa conferta (palm) and depths (surface, 45 and 90 cm) using microbial 16S rRNA gene amplicon sequencing. Water pH, oxygen, nitrogen, phosphorus, total phenolic contents and C/N ratio differed significantly between depths, but not tree species. Depth also strongly influenced microbial diversity and composition, while both depth and tree species exhibited significant impact on the archaeal communities. Microbial diversity was highest at the surface, where fresh leaf litter accumulates, and nutrient supply is guaranteed. Nitrogen was the core parameter correlating to microbial communities, but the interactive effects from various environmental variables displayed significant correlation to relative abundance of major microbial groups. Proteobacteria was the dominant phylum and the most abundant genus, Rhodoplanes, might be involved in nitrogen fixation. The most abundant methanogens and methanotrophs affiliated, respectively, to families Methanomassiliicoccaceae and Methylocystaceae. Our results demonstrated diverse microbial communities and provide valuable insights on microbial ecology in these extreme ecosystems.
Tropical peat swamp forests are important and endangered ecosystems, although little is known of their microbial diversity and ecology. We used molecular and enzymatic techniques to examine patterns in prokaryotic community structure and overall microbial activity at 0-, 10-, 20-, and 50-cm depths in sediments in a peat swamp forest in Malaysia. Denaturing gradient gel electrophoresis profiles of amplified 16S ribosomal ribonucleic acid (rRNA) gene fragments showed that different depths harbored different bacterial assemblages and that Archaea appeared to be limited to the deeper samples. Cloning and sequencing of longer 16S rRNA gene fragments suggested reduced microbial diversity in the deeper samples compared to the surface. Bacterial clone libraries were largely dominated by ribotypes affiliated with the Acidobacteria, which accounted for at least 27-54% of the sequences obtained. All of the sequenced representatives from the archaeal clone libraries were Crenarchaeota. Activities of microbial extracellular enzymes involved in carbon, nitrogen, and phosphorus cycling declined appreciably with depth, the only exception being peroxidase. These results show that tropical peat swamp forests are unusual systems with microbial assemblages dominated by members of the Acidobacteria and Crenarchaeota. Microbial communities show clear changes with depth, and most microbial activity is likely confined to populations in the upper few centimeters, the site of new leaf litter fall, rather than the deeper, older, peat layers.
Invasive apple snails, Pomacea canaliculata and P. maculata, have a widespread distribution globally and are regarded as devastating pests of agricultural wetlands. The two species are morphologically similar, which hinders species identification via morphological approaches and species-specific management efforts. Advances in molecular genetics may contribute effective diagnostic tools to potentially resolve morphological ambiguity. DNA barcoding has revolutionized the field of taxonomy by providing an alternative, simple approach for species discrimination, where short sections of DNA, the cytochrome c oxidase subunit I (COI) gene in particular, are used as 'barcodes' to delineate species boundaries. In our study, we aimed to assess the effectiveness of two mitochondrial markers, the COI and 16S ribosomal deoxyribonucleic acid (16S rDNA) markers for DNA barcoding of P. canaliculata and P. maculata. The COI and 16S rDNA sequences of 40 Pomacea specimens collected from six localities in Peninsular Malaysia were analyzed to assess their barcoding performance using phylogenetic methods and distance-based assessments. The results confirmed both markers were suitable for barcoding P. canaliculata and P. maculata. The phylogenies of the COI and 16S rDNA markers demonstrated species-specific monophyly and were largely congruent with the exception of one individual. The COI marker exhibited a larger barcoding gap (6.06-6.58%) than the 16S rDNA marker (1.54%); however, the magnitude of barcoding gap generated within the barcoding region of the 16S rDNA marker (12-fold) was bigger than the COI counterpart (approximately 9-fold). Both markers were generally successful in identifying P. canaliculata and P. maculata in the similarity-based DNA identifications. The COI + 16S rDNA concatenated dataset successfully recovered monophylies of P. canaliculata and P. maculata but concatenation did not improve individual datasets in distance-based analyses. Overall, although both markers were successful for the identification of apple snails, the COI molecular marker is a better barcoding marker and could be utilized in various population genetic studies of P. canaliculata and P. maculata.
The sika deer (Cervus nippon yesoensis) population in the Ramsar-listed Kushiro Wetland has increased in recent years, and the Ministry of the Environment of Japan has decided to take measures to reduce the impact of deer on the ecosystem. However, seasonal movement patterns of the deer (i.e., when and where the deer inhabit the wetland) remain unclear. We examined the seasonal movement patterns of sika deer in the Kushiro Wetland from 2013 to 2015 by analyzing GPS location data for 28 hinds captured at three sites in the wetland. Seasonal movement patterns were quantitatively classified as seasonal migration, mixed, dispersal, nomadic, resident, or atypical, and the degree of wetland utilization for each individual was estimated. The area of overlap for each individual among intra-capture sites and inter-capture sites was calculated for the entire year and for each season. Our results showed that the movement patterns of these deer were classified not only as resident but also as seasonal migration, dispersal, and atypical. Approximately one-third of the individuals moved into and out of the wetland during the year as either seasonal migrants or individuals with atypical movement. Some of the individuals migrated to farmland areas outside the wetland (the farthest being 69.9 km away). Half of the individuals inhabited the wetland all or most of the year, i.e., 81-100% of their annual home range was within the wetland area. Even among individuals captured at the same site, different seasonal movement patterns were identified. The overlap areas of the home ranges of individuals from the same capture sites were larger than those for individuals from different capture sites (e.g., mean of annual home range overlap with intra-capture sites: 47.7% vs. inter-sites: 1.3%). To achieve more effective ecosystem management including deer management in the wetland, management plans should cover inside and outside of the wetland and separate the population into multiple management units to address the different movement patterns and wetland utilization of the population.
The objective of this study is to determine the reduction efficiency of Chemical Oxygen Demand (COD) as well as the removal of color and Amaranth dye metabolites by the Aerobic-anaerobic Baffled Constructed Wetland Reactor (ABCW). The ABCW reactor was planted with common reed (Phragmite australis) where the hydraulic retention time (HRT) was set to 1 day and was fed with synthetic wastewater with the addition of Amaranth dye. Supplementary aeration was supplied in designated compartments of the ABCW reactor to control the aerobic and anaerobic zones. After Amaranth dye addition the COD reduction efficiency dropped from 98 to 91% while the color removal efficiency was 100%. Degradation of azo bond in Amaranth dye is shown by the UV-Vis spectrum analysis which demonstrates partial degradation of Amaranth dye metabolites. The performance of the baffled unit is due to the longer pathway as there is the up-flow and down-flow condition sequentially, thus allowing more contact of the wastewater with the rhizomes and micro-aerobic zones.
This work presents the first in-depth study of soil radioactivity in the mangrove forest of Bangladesh part of the Sundarbans. It used HPGe gamma-ray spectrometry to measure the amount of natural radioactivity in soil samples from Karamjal and Harbaria sites of the world's largest mangrove forest. The activity concentrations of most of the 226Ra (14±2 Bqkg-1 to 35±4 Bqkg-1) and 232Th (30±5 Bqkg-1 to 50±9 Bqkg-1) lie within the world average values, but the 40K concentration (370± 44 Bqkg-1 to 660±72 Bqkg-1) was found to have exceeded the world average value. The evaluation of radiological hazard parameters revealed that the outdoor absorbed dose rate (maximum 73.25 nGyh-1) and outdoor annual effective dose (maximum 0.09 mSvy-1) for most samples exceeded the corresponding world average values. The elevated concentration of 40K is mainly due to the salinity intrusion, usage of fertilizers and agricultural runoff, and migration of waste effluents along the riverbanks. Being the pioneering comprehensive research on the Bangladesh side of the Sundarbans, this study forms a baseline radioactivity for the Sundarbans before the commissioning of the Rooppur Nuclear Power Plant in Bangladesh.
The treatment of single and binary azo dyes, as well as the effect of the circuit connection, aeration, and plant on the performance of UFCW-MFC, were explored in this study. The decolorization efficiency of Remazol Yellow FG (RY) (single dye: 98.2 %; binary dye: 92.3 %) was higher than Reactive Black 5 (RB5) (single: 92.3 %; binary: 86.7 %), which could be due to monoazo dye (RY) requiring fewer electrons to break the azo bond compared to the diazo dye (RB5). In contrast, the higher decolorization rate of RB5 in binary dye indicated the removal rate was affected by the electron-withdrawing groups in the dye structure. The closed circuit enhanced about 2% of color and 4% of COD removal. Aeration improved the COD removal by 6%, which could be contributed by the mineralization of intermediates. The toxicity of azo dyes was reduced by 11-26% and the degradation pathways were proposed. The dye removal by the plants was increased with a higher contact time. RB5 was more favorable to be uptook by the plant as RB5 holds a higher partial positive charge. 127.39 (RY), 125.82 (RB5), and 58.66 mW/m3 (binary) of maximum power density were generated. The lower power production in treating the binary dye could be due to more electrons being utilized for the degradation of higher dye concentration. Overall, the UFCW-MFC operated in a closed circuit, aerated, and planted conditions achieved the optimum performance in treating binary azo dyes containing wastewater (dye: 87-92%; COD: 91%) compared to the other conditions (dye: 83-92%; COD: 78-87%).
The enhancement of up-flow constructed wetland-microbial fuel cell (UFCW-MFC) performance in energy retrieval from caffeine containing wastewater has been explored via various operating conditions (hydraulic retention time (HRT), multianode (MA), multicathode current collector (MC), external resistance). The anaerobic decaffeination and COD removal improved by 37 and 12% as the HRT extended from 1 to 5 d. The increment in contact time between the microbes and organic substrates promoted the degradation and contributed to higher power output (3.4-fold), CE (eightfold), and NER (14-16-fold). The MA and MC connections facilitated the electron transfer rate and the degradation rate of organic substrates in the multiple anodic zones, which enhanced the removal efficiency in the anaerobic compartment (Caffeine: 4.2%; COD: 7.4%) and led to higher electricity generation (Power: 4.7-fold) and energy recovery (CE: 1.4-fold; NER: 2.3-2.5-fold) compared to SA. The lower external resistance favored the growth of electrogens and induced higher electron flux, where the best treatment performance and electricity production was obtained when the external resistance approached the internal resistance. Overall, it was noteworthy that the optimum operating conditions were achieved with 5 d HRT, MA, and MC connection along with external resistance of 200 Ω, which significantly outperformed the initial conditions (1 d HRT, SA connection, and 1000 Ω) by 43.7 and 29.8% of caffeine and COD removal in the anaerobic compartment, respectively as well as 14-fold of power generation.
To identify seasonal fluxes and sources of dissolved inorganic nitrogen (DIN) wet deposition, concentrations and δ15N signatures of nitrate (NO3-) and ammonium (NH4+) in wet precipitation were measured at four typical land-use types in the Three Gorges reservoir (TGR) area of southwest China for a one-year period. Higher DIN fluxes were recorded in spring and summer and their total fluxes (averaged 7.58 kg N ha-1) were similar to the critical loads in aquatic ecosystems. Significant differences of precipitation δ15N were observed for NH4+-N between town and wetland sites in spring and between urban and rural sites in summer. For NO3--N, significant differences of precipitation δ15N were observed between town and rural sites in spring and between urban and town sites in autumn, respectively. Quantitative results of NO3--N sources showed that both biomass burning and coal combustion had higher fluxes at the urban site especially in winter (0.18 ± 0.09 and 0.19 ± 0.08 kg N ha-1), which were about three times higher than those at the town site. A similar finding was observed for soil emission and vehicle exhausts in winter. On the whole, DIN wet deposition averaged at 12.13 kg N ha-1 yr-1 with the urban site as the hotspot (17.50 kg N ha-1 yr-1) and regional NO3--N fluxes had a seasonal pattern with minimum values in winter. The contribution to NO3--N wet deposition from biomass burning was 26.1 ± 14.1%, which is the second dominant factor lower than coal combustion (26.5 ± 12.6%) in the TGR area during spring and summer. Hence N emission reduction from biomass burning, coal combustion and vehicle exhausts should be strengthened especially in spring and summer to effectively manage DIN pollution for the sustainable development in TGR area.
Soil ecosystems are home to a diverse range of microorganisms, but they are only partially understood because no single-cell sequencing or whole-community sequencing provides a complete picture of these complex communities. Using one of such metagenomics approaches, we succeeded in monitoring the microbial diversity and stress-response gene in the soil samples. This study aims to test whether known differences in taxonomic diversity and composition are reflected in functional gene profiles by implementing whole gene sequencing (WGS) metagenomic analysis of geographically dispersed soils from two distinct pristine forests. The study was commenced by sequencing three rainforest soil samples and three peat swamp soil samples. Soil richness effects were assessed by exploring the changes in specific functional gene abundances to elucidate physiological constraints acting on different soil systems and identify variance in functional pathways relevant to soil biogeochemical cycling. Proteobacteria shows abundances of microbial diversity for 52.15% in Royal Belum Reserved Forest and 48.28% in Raja Musa; 177 out of 1,391,841 and 449 out of 3,586,577 protein coding represent acidic stress-response genes for Royal Belum and Raja Musa, respectively. Raja Musa indicates pH 2.5, which is extremely acidic. The analysis of the taxonomic community showed that Royal Belum soils are dominated by bacteria (98% in Sungai Kooi (SK), 98% in Sungai Papan (SP), and 98% in Sungai Ruok (SR), Archaea (0.9% in SK, 0.9% in SP, and 1% in SR), and the remaining were classed under Eukaryota and viruses. Likewise, the soils of Raja Muda Musa are also dominated by bacteria (95% in Raja Musa 1 (RM1), 98% in Raja Musa 2 (RM2), and 96% in Raja Musa 3 (RM3)), followed by Archaea (4% in RM1, 1% in RM2, and 3% in RM3), and the remaining were classed under Eukaryota and viruses. This study revealed that RBFR (Royal Belum Foresr Reserve) and RMFR (Raja Musa Forest Reserve) metagenomes contained abundant stress-related genes assigned to various stress-response pathways, many of which did not show any difference among samples from both sites. Our findings indicate that the structure and functional potential of the microbial community will be altered by future environmental potential as the first glimpse of both the taxonomic and functional composition of soil microbial communities.
A new species of gecarcinucid freshwater crab of the genus Parathelphusa H. Milne Edwards, 1853, is described from freshwater swamp habitats in Pekanbaru, Riau Province, in central-eastern Sumatra, Indonesia. Parathelphusa pardus sp. nov., has a very distinctive colour pattern, and in this respect, resembles P. maindroni (Rathbun, 1902) from Sumatra and Peninsular Malaysia; P. batamensis Ng, 1992, from Batam Island, Indonesia; P. reticulata Ng, 1990, from Singapore; and P. oxygona Nobili, 1901, from western Sarawak. It can be distinguished from these species and congeners by a suite of carapace, ambulatory leg, thoracic sternal and most importantly, male first gonopod characters.
This paper presents the results for surface water quality parameters measured in the Setiu Wetland, on the east coast of Malaysia, which feeds into the southern part of the South China Sea. There are no previous studies dealing with the seasonal and spatial variation of water quality in this area, despite numerous anthropogenic inputs into this ecologically and economically important wetland. The parameters measured were salinity, temperature, dissolved oxygen (DO), pH, biological oxygen demand (BOD) and total suspended solids (TSS). These parameters were sampled monthly from October 2009 to September 2010, during both the wet and dry seasons, at ten sampling stations distributed throughout the area. The physical water quality parameters were measured in situ whilst TSS and BOD were determined using the standard methods. A deterioration of water quality in the Setiu Wetland was observed in areas near agriculture and aquaculture activities. This was expected to be as a result of the use of fertilisers, waste from fish farm food and the waste products of aquaculture. The parameters measured showed lower mean values of surface salinity, temperature, DO, pH and TSS during the wet season relative to the dry season. In contrast, the concentration of BOD was high during the wet season and lowest in the dry season. Results obtained from this study clearly showed the surface physical water quality for the Setiu Wetland was highly influenced by anthropogenic activities and seasonal variation. Therefore, both factors must be considered to move towards proper management of this wetland.
Setiu Wetland is located in the southern part of South China Sea, Malaysia. This wetland has diverse ecosystems that represent a vast array of biological diversity and abundance in utilizable natural resources. However, there are large scales of aquaculture activities within and nearby the wetland which could threaten the ecosystems of this area. Thus, the main goal of the study was to assess the impact of these activities through the measurement of physico-chemical water quality parameters and then compare this to a previous study carried out in the same study area. The parameters (salinity, temperature, pH, dissolved oxygen, biological oxygen demand and total suspended solids) were monitored monthly at the surface water from July to October 2008. The results showed that the impact of aquaculture activities on the water quality in the area with dissolved oxygen and total suspended solids concentrations were considerably lower than those observed previously. With respect to the Malaysian Marine Water Quality Criteria and Standard, most of the level of parameters measured remained Class 1, suggesting the physico-chemical environment were in line with sustainable conservation of the marine protected areas and marine parks of this wetland area.
Due to conservation and rehabilitation efforts, mangrove forests represent some of the largest environmental niches in Malaysia. However, there is little information on the potential risks posed by mosquitoes that are directly and indirectly associated with mangrove forests. To study the potential health risk to humans active within and in close vicinity of mangrove forests, this research focused on the day biting habits of mosquitoes in mangrove forests of Kedah, Malaysia. The bare leg catch (BLC) method was used to collect adult mosquitoes during a 12-h period from 7:30 a.m. to 7:30 p.m. in both disturbed and less disturbed areas of mangroves. In total, 795 adult mosquitoes from 5 genera and 8 species were collected, and over 65% of the total mosquitoes were collected from the less disturbed area. The predominant species from the less disturbed area was Verrallina butleri; in the disturbed area the dominant species was Culex sitiens. The peak biting hour differed for each species, with Aedes albopictus and Cx. sitiens recorded as having a bimodal biting activity peak during dawn and dusk. For Ve. butleri an erratic pattern of biting activity was recorded in the less disturbed area but it peaked during the early daytime for both collection points. Overall, the distinct pattern of day biting habits of mosquitoes within mangroves peaked during dawn and dusk for the less disturbed area but was irregular for the disturbed area throughout the day. The presence of vectors of pathogens such as Ae. albopictus for both areas raises the need for authorities to consider management of mosquitoes in mangrove forests.