Imposex Cases in Snails (Thais Spp.) in the West Coast of Peninsular Malaysia

The objective of this research was to assess imposex cases in Thais spp. from the west coast of Peninsular Malaysia with respect of identification of imposex severity by using the vas deferens sequence (VDS) scheme and relative penis length (RPL), the relationship between imposex level and sex ratio of Thais spp. through statistical analysis and relationship between length of imposex organs (VDS and RPL) and length of shell size parameters (height, edge and aperture). The present study also observed the relationship between imposex cases and human activities in the sampling areas. Sampling activities were carried out at 27 sites from five states along the west coast of Peninsular Malaysia from November 2001 to April 2004. The sampling sites were chosen based on the occurrence of Thais spp. In the present study, four species of Thais were chosen and they were Thais gradata, Thais tuberosa, Thais hippocastanum and Thais bitubercularis. These snails are well distributed along the rocky shore of the west coast of Peninsular Malaysia. T. gradata was found as the most abundant species, followed by T. tuberosa, T. hippocastanum and T. bitubercularis. The presence and development of imposex were observed in four species of Thais collected from the 27 sites along the west coast of Peninsular Malaysia. Almost 100% of female snails showed imposex characters in various degrees. The observed imposex developments in this study included a pseudopenis and / or a vas deferens sequence (VDS) and could be classified as stage 1, 2, 3, 4, 5 and 6 according to the VDS classification scheme. Most of the imposex cases occurred at stage 2 (60%), followed by stage 1 (19%) then stage 4 (8 %). While the rest were stage 3, 5 and 6. The serious level of imposex that is stage 6 formed a penis and VDS size grew 100% similar with the size of male’s sexual organs. The highest relative penis length (RPL) recorded in this study was 84.62%. The sex ratio of affected populations was deviated from normal ratio. There was also a significant correlation showing the increment of RPL caused the decrease on female population. From Pearson’s correlation coefficient, negative correlation coefficients found between imposex severity (which represent as RPL) with percentages of female population in T. gradata (r = - 0.0485, p > 0.05), T. hippocastanum (r = - 0.6034, p > 0.05) and T. bitubercularis (r = – 0.0707, p > 0.05). Furthermore, there was no obvious relationship between length of imposex organs (penis and VDS) and length of shell size parameters (height, edge and aperture). The incidence of imposex and the degree of imposex development in individuals were higher in samples collected from marinas, ports and areas with high boating and shipping activities

Program kitar semula fabrik pupuk warga UPM budayakan aktiviti kitar semula

SERDANG, 9 Nov – Fakulti Sains, Universiti Putra Malaysia (UPM) melancarkan program Kitar Semula Fabrik bagi memupuk budaya kitar semula fabrik di kalangan pelajar dan warga UPM

Estimation of GHG emission from different land use changes associated with oil palm plantation

The release of nitrous oxide (N2O) from agricultural activities contributes to the increase of greenhouse gases in the atmosphere. In this study, the amount of nitrogen fertilizer used in an oil palm plantation of different stages (immature and mature) was estimated. Data of fertilizing scheme at the oil palm plantation for oil palms varying in age (planted between 1986 and 2009) was used. Estimation of nitrous oxide emission and the resulting CO2-equivalent emission were calculated for each category of the oil palm. The amount of N-fertilizer applied were between 194-260 kg N/ha. The resulting N2O emissions were between 2.75-3.13 kg N2O-N/ha, which corresponds to CO2-equivalent of between 261.99-346.94 kg CO2-eq/ha. Despite increase of N2O emission from immature stage until maturely-developed up to 20 years, there is no clear relationship between N2O emission per ha and the age of oil palm. Generally, the N2O emissions found in this study are still low compared to the default value for synthetic nitrogen fertilizer-induced emissions for tropical regions

Field survey and spatial distribution of Tropical Neogastropod, Thais spp., along Malaysian Coastal Area.

Tropical marine neogastropod has been proposed to be a bioindicator for marine pollution. A field survey was conducted to determine the spatial distribution of Thais spp. along the Malaysian coastline. The density of Thais spp. in each area was calculated using the timed search method. More than 40 percent of the total surveyed sites were identified to have Thais spp. present. On average, the abundance rating for Thais spp. in Malaysia was a common species with density (D) of about 720 individuals/hour/ person. About 50 percent of Thais spp. habitats can be categorised as a frequent-occasional abundance rating. This study found that Thais spp. prefer to occupy a sandy or mixed sedimentary beach with boulder(s) either naturally existing or a man-made wave barrier along reclaimed beaches. This study found that a suitable habitat for Thais spp. must consist of prey items being present, exposure to the open sea and strong waves, and must be located within tidal activities. Limited human activities around their habitat do not have direct effects on Thais spp. presence. However, further investigations on the implications of human activities in the habitat of Thais spp. along Malaysian coastal areas should be conducted

Nitrous oxide emission from nitrogen fertiliser application in oil palm plantation of different stages

The release of nitrous oxide (N2O) from agricultural activities contributes to the increase of greenhouse gases in the atmosphere. In this study, the amount of nitrogen fertiliser used in an oil palm plantation of different stages (immature and mature) was estimated. Data of fertilising scheme at the oil palm plantation for oil palms varying in age (planted between 1986 and 2009) was used. Estimation of nitrous oxide emissions and the resulting CO2-equivalent (CO2-eq) emissions were calculated for each category of the oil palm. The amounts of N-fertiliser applied were between 102137 kg N/ha. The resulting N2O emissions were between 19.07-22.10 kg N2O-N/ha, which corresponds to CO2-eq of between 2223.53-2700.42 kg CO2-eq/ha. It was also estimated that about 29.87-34.63 g CO2 were emitted per MJ crop. The N2O emission per ha oil palm was found to decrease from immature stage until maturely-developed stage spanning 20 years. The CO2-eq amount decreased only after ten years of oil palm development. The results were also compared for synthetic nitrogen fertiliser-induced emissions within tropical regions

Uptake of Mn and Cd by wild water spinach and their bioaccumulation and translocation factors

Polluted ponds and lakes close to agricultural activities become the exposure route of manganese (Mn) and cadmium (Cd) to aquatic plants in near vicinity. Therefore, a study of the uptake, bioaccumulation, and translocation of Mn and Cd by the water spinach (Ipomoea aquatica) is presented in this paper. Different concentrations of Mn and Cd were added to the hydroponic nutrient solution that was used to grow the plants for the heavy metal uptake experiment under greenhouse conditions. The plant samples exposed to heavy metals were collected to determine the metal concentrations using atomic absorption spectroscopy (AAS) and the metal concentrations were found for Mn was between 1.589 to 9.696 µg/g and Cd from 5.309 to 10.947 µg/g. The correlation and regression results showed that the water-to-shoot bioaccumulation factor (BAF) decreased for Mn, while root-to-shoot translocation factor (TF) values increased in the order Cd > Mn to the increasing levels of metals in the water. Furthermore, it was revealed from the two-way analysis of variance (ANOVA) that the different metal types influenced the BAF and TF values at different metal concentration treatments

Johor Strait as a hotspot for trace elements contamination in Peninsular Malaysia

Present study was conducted to evaluate current status of trace elements contamination in the surface sediments of the Johor Strait. Iron (2.54 ± 1.24%) was found as the highest occurring element, followed by those of zinc (210.45 ± 115.4 μg/g), copper (57.84 ± 45.54 μg/g), chromium (55.50 ± 31.24 μg/g), lead (52.52 ± 28.41 μg/g), vanadium (47.76 ± 25.76 μg/g), arsenic (27.30 ± 17.11 μg/g), nickel (18.31 ± 11.77 μg/g), cobalt (5.13 ± 3.12 μg/g), uranium (4.72 ± 2.52 μg/g), and cadmium (0.30 ± 0.30 μg/g), respectively. Bioavailability of cobalt, nickel, copper, zinc, arsenic and cadmium were higher than 50% of total concentration. Vanadium, copper, zinc, arsenic and cadmium were found significantly different between the eastern and western part of the strait (p < 0.05). Combining with other factors, Johor Strait is suitable as a hotspot for trace elements contamination related studies

An assessment of selected trace elements in intertidal surface sediments collected from the Peninsular Malaysia

Concentrations of 11 trace elements (V, Cr, Co, Ni, Cu, Zn, As, Ag, Cd, Pb, and U) were determined in the intertidal surface sediments of Peninsular Malaysia. The average trace element concentrations are ranked as follows: Zn>V>As>Cr>Pb>Cu>Ni>Co>U>g>Cd. Interim Sediment Quality Guidelines (ISQGs) employed in present study are the Australia and New Zealand joint guideline (ANZECC/ARMCANZ), and the Hong Kong authorities. From the pooled data, none of these trace elements have the average concentration above the ISQG-high values. However, As and Ag average concentrations were over the ISQG-low values. Some elements were found to have the average concentration above the ISQG-high and/or ISQG-low in certain locations, including Kampung Pasir Putih (JPP), Lumut Port (ALP), Kuala Perai (PKP), Port Dickson (NPD), and others. The lowest and highest concentrations in a specific sampling location and maritime area varied among the elements, variations that were greatly affected by natural and anthropogenic activities in a given area. For each trace element, there were various levels of concentration among the sampling locations and maritime areas. These patterns indicated pollutant sources of an element for each area perhaps derived from nearby areas and did not widely distributed to other locations. It is necessary for Malaysia to develop an ISQG for effective quick screening and evaluation of the coastal environment of Peninsular Malaysia

Determination of Mn and Pb uptake by vetiver grass (Vetiveria zizanioides) with different shoot length in artificial running water system

Vetiveria zizanioides has been known as a phytoremediation agent and widely uses in water conservation works. However, there is a need to improve performance of this plant in removing pollutant in water system. Therefore, this study was conducted to measure Water Quality Index (WQI) improvement in the system installed by vetiver grass (VG) with trimmed and untrimmed shoot, identify rate of metal uptake and visual changes of VGs exposed in high concentration of lead (Pb) and Manganese (Mn). Artificial water system was setup by installing Class III water samples taken from pond within Universiti Putra Malaysia (UPM). Plants were exposed to 15 mg/L of Pb and Mn (192 h) and harvested at different time intervals. The WQI of water samples has improved to class II after treated with VGs. Independent sample T-test found that no significant different of Pb and Mn concentration between trimmed and untrimmed plants, but there were significant different of those metal concentration between root and shoot of VGs (p<0.05). Higher concentration of Pb detected in root while in shoot, higher Mn concentration. Chlorosis of the plant leaves was seen on day 6 for trimmed and day 7 for untrimmed. No chlorosis observed on VGs in control experiment. This study found that VG have great potential in improving WQI for running water and have good tolerance ability to high level of Pb and Mn despite no differences in metal uptake between plants with trimmed and untrimmed shoot. Metal accumulation in different organ varied significantly depending upon the role of the metal

Imposex study on Thais bitubercularis in Merambong shoal, Johor

Imposex in Thais bitubercularis was observed in Merambong Shoal. About 18% from female individuals of the species were found to have male sexual organs, which is imposex at various stages. Stage 2 is the highest level of imposex discovered. The imposex occurrence was determined by calculated the proportion of females with imposex to the total number of female in sample and the degree of imposex was assessed using the vas deference sequence index and the percentage of females possessing the imposex characteristics. There are no significant relationship between the shell height and the number of spines between the degrees of imposex occurrence in T. bitubercularis. The present study also provided an overview of the present condition of the population health of T. bitubercularis at Merambong Shoal. Based on the male to female ratio, the population in Merambong Shoal showed in normal ratio which is 5:7 and this ratio is closer to normal ratio condition which is 4:7. The imposex incidence in the population reveals that T. bitubercularis in Merambong shoals are no exception from being exposed with the pollutant that can promote imposex occurrence. Tributyltin (TBT) which was recorded as the most suspected pollutant causing imposex in gastropod is expected contaminating the Johor Straits. However, the low incidence of imposex can be explain as the sample was collected from a shoal that receive high water current. The condition causing very low suspended particles or organic matter in the sediment resulting low TBT deposition in the sediment, then automatically low uptake by the biota living in the shoal