Effect of domestic effluent, agricultural and industrial pollution on aquatic macroinvertebrates with emphasis on chironomidae (diptera) at community, individual and molecular levels.

Kelimpahan dan kepelbagaian makroinvertebrata serta parameter air dikaji di lima sungai Lembangan Sungai Juru di utara semenanjung Malaysia; Sungai Ceruk Tok Kun (CTKR), Sungai Pasir (PR), Sungai Permatang Rawa (PRR), Sungai Kilang Ubi (KUR) dan Sungai Juru (JR). Abundance and diversity of macroinvertebrates as well as physico-chemical parameters of the water were investigated in five rivers of the Juru River Basin in northern Peninsula Malaysia; Ceruk Tok Kun River (CTKR), Pasir River (PR), Permatang Rawa River (PRR), Kilang Ubi River (KUR), and Juru River (JR)

Some Aspects Of Ecology And Genetics Of Chironomidae (Diptera) In Rice Field And The Effect Of Selected Herbicides On Its Population

Kajian ekologi dan molekul dijalankan terhadap serangga akuatik Chironomidae (Diptera) yang mendiami kawasan sawah padi di Stesen Kaiian Pertanian Bukit Merah (BMAES), Seberang Perai, Pulau Pinang, Malaysia. Penyiasatan terhadap taburan dan kelimpahan chironomid (Chironomidae: Diptera) menunjukkan bahawa taburan populasi larva chironomid meningkat dan menurun mengikut perubahan dinamik ekosistem sawah padi. Kepadatan tertinggi dalam musim pertama ialah 294.39m-2 dan 306.37m-2 dalam musim kedua. Penyampelan larva setiap dua minggu selama dua musim penanaman 2004/2005 menunjukkan bahawa Chironomus kiiensis adalah spesies yang paling dominan ditemui. Manakala empat lagi spesies, Polypedilum lrigonus, Tanytarsus formosanus, Tanypus punctipennis and Clinotanypus sp didapati dalam jumlah yang rendah walaupun ditemui pada sepanjang masa sawah padi dipenuhi air. An ecological and molecular study was conducted on the aquatic insect Chironomidae (Diptera) inhabiting the rice field in Bukit Merah Agricultural Research Station (BMAES), Seberang Perai, Pulau Pinang Malaysia. Investigation on the distribution and abundance of chironomid larvae (Chironomidae: Diptera) showed that the larval population fluctuated following the dynamic changes in rice field ecosystem. The maximum density in the first season was 294.39 m-2 and 306.37 m-2 in the second season. Biweekly sampling of larvae over two rice growing seasons of 2004/2005 revealed that Chironomus kinesis was the most abundant species while four other species Polypedilum trigon us, Tanytarsus formosanus, Tanypus punctipennis and Clinotanypus sp were found in low numbers although they occurred during all rice wet phases

Effect of environmrntal disturbances on odonata assemblages along a tropical polluted river

Odonata larvae have been intensively used as bioindicators for freshwater pollution as their community structure closely follow changes in the environment and habitat settings. In this study, 28 taxa of Odonata larvae were collected from three stations (upper, middle and lower) of a polluted river in Malaysia. The upper river basin receives effluents from an oil palm plantation. However, the middle station is presumably contaminated with anthropogenic wastes. The lower station is found to receive polluted discharges from aquaculture outlet. Several environmental parameters of water and sediment were continuously measured during the study. The water parameters showed no significant differences amongst the three stations. The species richness of Odonata was 22, 24 and 20 in the upper, middle and lower stations, respectively. The abundance of Odonata was significantly different among the studied sites. The tolerant damselfly, Pseudagrion sp. (41.22%), and facultative dragonflies, Onychothemis sp. (17.12%), were the most dominant taxa along the river stations. Onychothemis sp. and Paragomphus capricornis were equally important at the upper station [Important Species Index (ISI) 25.3 and 24.2%, respectively]. Pseudagrion sp. only scored an ISI value of 9.7%. Pseudagrion sp., P. capricornis and Onychothemis sp. were dominant in the middle station (ISI: 41.2%, 25.9% and 10.9% respectively), and Pseudagrion sp., Onychothemis sp. and Prodasineura sp. dominated the areas with dense growth of submerged aquatic weeds Hydrilla sp. in the lower station (ISI: 47.9, 24.5 and 13.8%, respectively). On the basis of the variations in larval abundance and ISI values, microhabitats differences partly in response to different types of pollutions entering the water structured the Odonata communities in this river basin

A comparative study of health risks of Fe and Ni in the vegetables collected from selected farming areas of Peninsular Malaysia

This study investigated the concentrations of Ni and Fe in 18 vegetables (12 fruit types and 6 leafy types) and their habitat topsoils collected from three farming sites in Peninsular Malaysia. The levels of Ni and Fe are all significantly (P<0.05) higher in the leafy vegetables than those in the fruit vegetables. It is found that the Ni levels in the vegetables are highly correlated with the three geochemical and non-resistant fractions of the habitat topsoils. This indicated that Ni geochemical fractions in the habitat topsoils are considered readily and potentially bioavailable to the vegetables. The Fe levels in the vegetables are highly correlated with the ‘acid-reducible’ fraction of the habitat topsoils, indicating the Fe transfer of this geochemical fraction is likely to occur to the vegetables. The positive relationships indicated the potential of edible vegetables as good biomonitors of Ni pollution in the habitat topsoils. For the health risk assessment, all the target hazard quotient values for Ni and Fe in the 18 vegetables investigated in both adult and children are all below 1.00. This indicated that there was no non-carcinogenic risk of Ni and Fe to the consumers for both adults and children

Biomonitoring of heavy metals in intertidal snails: the importance of aquatic ecosystem management

Samplings of intertidal snails were done in January-April 2005 along the northern part of Peninsular Malaysia. Five taxa of intertidal snails (Pomacea canaliculata, Nerita lineata, Chicoreus capucinus, Thais sp. and Telescopium telescopium) were analysed for Cd, Cu, Fe, Ni, Pb and Zn. Based on the analyses of the different species, it can be concluded that 1) the highest and the lowest levels of metals in all species were Fe and Cd, respectively, which is in line with the abundance of these metals in the nature; 2) the levels of metals in the soft tissues and shells of the snails species were significantly different which were due to metal handling strategies and regulations; and 3) these metal accumulations in the soft tissues and shells shed lights on effective management of marine ecosystem in future studies

Heavy metals in barnacles Balanus sp.: from biomonitoring to coastal management

This study determined the levels of Cd, Cu, Fe, Ni, and Zn in the soft tissues and shells of barnacles (Balanus sp.) collected from the Kuala Juru, Sebatu, Sg. Ayam and Kg. Pasir Puteh, Peninsular Malaysia, obtained in 2008. The metal concentrations (μg/g dry weight) in the soft tissues of Balanus sp. received from four sites in Peninsular Malaysia ranged from 2.93-4.17 for Cd, 20.2-92.5 for Cu, 480-1193 for Fe, 6.40-18.0 for Ni, and 224-414 for Zn. Based on the present data, the trace metal bioavailability’s to the Balanus in all the populations, especially in a known polluted site at Kg. Pasir Puteh is low. Overall, this preliminary baseline data can be used for regular ecological monitoring for the effective management of the coastal area in Malaysia

Human health risk assessments of trace metals on the clam Corbicula javanica in a tropical river in Peninsular Malaysia

This study aimed to analyse ten trace metal concentrations in the edible part of the freshwater clam Corbicula javanica and to provide a critical assessment of the potential risks to human health through consumption of this clam as food based on well-established indices and food safety guidelines. The clams were captured from a pristine original site and transplanted to other sites with different environmental qualities. The trace metal levels in the edible total soft tissue (TST) of the clam were below those of the food safety guidelines referred to except for Pb, which exceeded the permissible limit set by the European Commission (2006) and the US Food and Drug Administration/ Center for Food Safety and Applied Nutrition); Interstate Shellfish Sanitation Conference. (USFDA/CFSAN; ISSC) (2007). The estimated daily intake (EDI) values of the clam were found to be lower than the oral reference dose and the calculated target hazard quotient (THQ) and total THQ were found to be less than 1. Therefore, in conclusion, the human health risk for consumption of TST of C. javanica at both average and high-level were insignificant regardless of the environment it was exposed to

Congruence patterns of aquatic communities in a tropical river basin, Malaysia

The loss of aquatic biodiversity in tropical streams of SE Asia is evident due to increasing anthropogenic activities. Therefore, there is a necessity for immediate and feasible conservation plans. Effective conservation planning depends on successful application of surrogate groups. However, progress of this approach is hindered by the paucity of relevant reports based on cross-taxon congruence analysis. In this study, we investigated congruence patterns among aquatic groups (Plecoptera, Trichoptera, Ephemeroptera, Odonata and fish) in six rivers located in the Kerian River Basin (KRB), Malaysia. Species richness was significantly correlated among aquatic groups (except for Ephemeroptera and Trichoptera where r = 0.040 and P = 0.202). The strongest relationship in species richness was reported between Ephemeroptera and Plecoptera. The Mantel's r coefficient of similarity matrices (based on the Bray-Curtis distance measure) showed a positive correlation between the matrices of Ephemeroptera-Trichoptera and Plecoptera-Trichoptera. However, a negative relationship was reported between Odonata-fish matrices. The relationships between average Trichoptera-Odonata distance to the centroid (i.e. beta diversity) among the aquatic groups were also investigated. The strongest relationship in the average to the centroids was reported between Ephemeroptera and Odonata (R2 = 0.424, P < 0.05). However, the weakest relationship was reported between Trichoptera and fish with R2 value of 0.024. It is concluded that richness of Plecoptera, Odonata and fish showed correlations patterns, and these can be used as surrogates for each other with some restrictions

Effects of anthropogenic activities on the heavy metal levels in the clams and sediments in a tropical river

The present study aimed to assess the effects of anthropogenic activities on the heavy metal levels in the Langat River by transplantation of Corbicula javanica. In addition, potential ecological risk indexes (PERI) of heavy metals in the surface sediments of the river were also investigated. The correlation analysis revealed that eight metals (As, Co, Cr, Fe, Mn, Ni, Pb and Zn) in total soft tissue (TST) while five metals (As, Cd, Cr, Fe and Mn) in shell have positively and significantly correlation with respective metal concentration in sediment, indicating the clams is a good biomonitor of the metal levels. Based on clustering patterns, the discharge of dam impoundment, agricultural activities and urban domestic waste were identified as three major contributors of the metals in Pangsun, Semenyih and Dusun Tua, and Kajang, respectively. Various geochemical indexes for a single metal pollutant (geoaccumulation index (I geo), enrichment factors (EF), contamination factor (C f) and ecological risk (Er)) all agreed that Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn are not likely to cause adverse effect to the river ecosystem, but As and Pb could pose a potential ecological risk to the river ecosystem. All indexes (degree of contamination (C d), combined pollution index (CPI) and PERI) showed that overall metal concentrations in the tropical river are still within safe limit. River metal pollution was investigated. Anthropogenic activities were contributors of the metal pollution. Geochemical indexes showed that metals are within the safe limit

Water quality and aquatic insects study at the Lower Kinabatangan River Catchment, Sabah: in response to weak La Niña event

A study on water quality and aquatic insects has been conducted at the Lower Kinabatangan River Catchment, Sabah, Malaysia. The quality of water surface and aquatic insects’ composition were studied in streams near to oil palm plantation (OP), secondary forest (SF) and oxbow lake (OB). The study also aims to identify the seasonal variation in the aquatic insects’ composition during the weak La Niña event. A total of 135 water samples and 1678 aquatic insect individuals (four orders and 14 families) were collected during fieldwork campaign that spanned over the inter-monsoonal period, wet and dry seasons between October 2004 and June 2005. OP has the highest abundance of aquatic insects particularly during the dry season. Biological indices showed that all stations were in moderate water category. The water quality index (WQI) was calculated and indicated that the quality of the river categorised into Class II. Discriminant analysis (DA) was employed to classify the independent variables into mutually-exclusive groups. Suspended sediment (SS) and chemical oxygen demand (COD) were high during the wet season. Suspended sediment was high in oxbow lake and could be a strong reason behind low abundance of aquatic insects. Precipitation anomalies were found to affect seasonal variations of water quality and aquatic insects at the Lower Kinabatangan River