Richard Lim is an aquatic ecotoxicologist. His research interests are in the ecotoxicology of pesticides, heavy metals, persistent organic chemicals, endocrine disrupting chemicals and salinity with a focus on assessing the impacts and risks of these contaminants and their mixtures in aquatic systems. It focuses on anthropogenic impacts of agricultural and mining activities as well as urbanisation including sewage effluent on these ecosystems.His research involves the use of a suite of bioassays spanning a range of ecological scales from in vitro and in vivo bioassays to population and community studies in the laboratory, mesocosms and field.His research also encompasses a range of test organisms from bacteria to algae and aquatic plants to invertebrates and fish. Richard also has expertise in limnology particularly in stream ecology and pollution studies in relation to stream health, ecology of wetlands including ricefields, and zooplankton taxonomy.The information generated from his research contributes to an understanding of how anthropogenic activities impact on the health of ecosystems leading to development of appropriate management strategies.In collaboration with researchers in UTS Environmental Engineering his research includes assessing the ability of innovative effluent treatment technologies in removing toxicants using an effects-based approach.
Membership to Professional SocietiesAustralian Society for Limnology (Life member)Australasian Society for Ecotoxicology
Ecotoxicology of pesticidesImpact of endocrine disrupting chemicals on the aquatic faunaImpact of mining on stream macroinvertebratesStream pollution studiesEcology of wetlands (lakes and rivers)Zooplankton taxonomy
LimnologyEcotoxicologyGeneral biology and ecologyEnvironmental engineering
Abbas, F, Porojan, C, Mowe, MAD, Lehane, M, Mitrovic, SM, Lim, RP, Yeo, DCJ & Furey, A 2020, 'Sample extraction and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method development and validation for the quantitative detection of cyanobacterial hepatotoxins and neurotoxins in Singapore's reservoirs', MARINE AND FRESHWATER RESEARCH, vol. 71, no. 5, pp. 673-688.View/Download from: Publisher's site
Porojan, C, Abbas, F, Mowe, MAD, Lehane, M, Mitrovic, SM, Lim, RP, Yeo, DCJ & Furey, A 2020, 'Survey of microcystins in Singapore's reservoirs using liquid chromatography-tandem mass spectrometry (LC-MS/MS)', MARINE AND FRESHWATER RESEARCH, vol. 71, no. 5, pp. 659-672.View/Download from: Publisher's site
Gaw, S, Harford, A, Pettigrove, V, Sevicke-Jones, G, Manning, T, Ataria, J, Cresswell, T, Dafforn, KA, Leusch, FD, Moggridge, B, Cameron, M, Chapman, J, Coates, G, Colville, A, Death, C, Hageman, K, Hassell, K, Hoak, M, Gadd, J, Jolley, DF, Karami, A, Kotzakoulakis, K, Lim, R, McRae, N, Metzeling, L, Mooney, T, Myers, J, Pearson, A, Saaristo, M, Sharley, D, Stuthe, J, Sutherland, O, Thomas, O, Tremblay, L, Wood, W, Boxall, AB, Rudd, MA & Brooks, BW 2019, 'Towards Sustainable Environmental Quality: Priority Research Questions for the Australasian Region of Oceania.', Integrated environmental assessment and management, vol. 15, no. 6, pp. 917-935.View/Download from: Publisher's site
Environmental challenges persist across the world, including the Australasian region of Oceania, where biodiversity hotspots and unique ecosystems such as the Great Barrier Reef are common. These systems are routinely affected by multiple stressors from anthropogenic activities, and increasingly influenced by global megatrends (e.g., the food-energy-water nexus, demographic transitions to cities) and climate change. Here we report priority research questions from the Global Horizon Scanning Project, which aimed to identify, prioritize, and advance environmental quality research needs from an Australasian perspective, within a global context. We employed a transparent and inclusive process of soliciting key questions from Australasian members of the Society of Environmental Toxicology and Chemistry. Following submission of 78 questions, 20 priority research questions were identified during an expert workshop in Nelson, New Zealand. These research questions covered a range of issues of global relevance, including research needed to more closely integrate ecotoxicology and ecology for the protection of ecosystems, increase flexibility for prioritizing chemical substances currently in commerce, understand the impacts of complex mixtures and multiple stressors, and define environmental quality and ecosystem integrity of temporary waters. Some questions have specific relevance to Australasia, particularly the uncertainties associated with using toxicity data from exotic species to protect unique indigenous species. Several related priority questions deal with the theme of how widely international ecotoxicological data and databases can be applied to regional ecosystems. Other timely questions, which focus on improving predictive chemistry and toxicology tools and techniques, will be important to answer several of the priority questions identified here. Another important question raised was how to protect local cultural and social values and maintain indigenous engageme...
Wood, RJ, Mitrovic, SM, Lim, RP, Warne, MSJ, Dunlop, J & Kefford, BJ 2019, 'Benthic diatoms as indicators of herbicide toxicity in rivers – A new SPEcies At Risk (SPEARherbicides) index', Ecological Indicators, vol. 99, pp. 203-213.View/Download from: Publisher's site
© 2018 Elsevier Ltd Benthic diatom communities are used widely as indicators of river health due to their rapid response to changes in water quality. The ability for diatom-based indices to detect eutrophication has been well documented; however, an index designed specifically to detect herbicide impacts is yet to be established. This is required as herbicide contamination of rivers is common in agricultural regions and poses a potential threat to aquatic ecosystems. This study developed a new biomonitoring index (SPEARherbicides) using benthic diatom communities to detect the toxic impacts of herbicides in rivers, and tested it across 14 rivers in the Great Barrier Reef catchment area, Australia. The new index uses diatom species traits to classify diatoms as either sensitive or tolerant to herbicides and calculates the fraction of sensitive taxa within a sample. The SPEARherbicides index showed a decline in herbicide sensitive diatoms with increasing herbicide toxicity of the sites. The impacts of herbicide toxicity on the diatom community were only apparent after the wet season when aqueous herbicide concentrations typically peak and diatoms were able to recover during the dry season when herbicide concentrations were lower. SPEARherbicides values had a negative relationship with the percentage of grazing and cropping in catchments but had a positive relationship with the percentage of conservation in catchments. SPEARherbicides also had a negative relationship with co-occurring potential stressors such as nutrients and total suspended solids.
Zhao, C, Pan, T, Dou, T, Liu, J, Liu, C, Ge, Y, Zhang, Y, Yu, X, Mitrovic, S & Lim, R 2019, 'Making global river ecosystem health assessments objective, quantitative and comparable.', The Science of the total environment, vol. 667, pp. 500-510.View/Download from: Publisher's site
Assessing and comparing global river ecosystem health in an objective and quantitative way remains a major challenge. In this study the widely-used semi-quantitative methods Rapid Biological assessment Protocols (RBPs) was used to determine the health of rivers. The findings were then compared to the results derived from our new UAV (Unmanned aerial vehicles) orthophotographic imagery method. This method quantitatively and objectively assesses river ecosystem health. As a comparison, our method was used to quantitatively measure distance and areas of a range of hydrological and biological attributes thus improving the accuracy of distance- and area-related indices, consequently avoiding subjective errors in these estimations that is fraught in methods like the RBPs. To strengthen the objectivity of the assessment the weights of these indices were objectively determined using the entropy weighting method. This new method was then tested using 9551 UAV orthophotographs taken over six field campaigns. It performed satisfactorily, showing that in our study area the health status of mountain rivers was the best with the highest score of 0.94 out of 1.0. Temporally, the health of the river was better in summer (0.65) compared with that in autumn (0.40). Changes in river ecosystem health were driven by variations in biology and water quality. In contrast the outputs of RBPs, especially in relation to distance and area indices, had ~ 20% uncertainty due to visual errors and subjectivity in estimations by observers. The UAV orthophotographic imaging method proposed in this study can improve the ability to compare the health of rivers across different periods and regions throughout the globe.
Karami, A, Karbalaei, S, Ebrahimi, M, Ismail, A, Jahromi, MF, Simpson, SL, Eghtesadi Araghi, P, Lim, RP & Liang, JB 2018, 'Changes in nutritional values induced by butachlor in juvenile diploid and triploid Clarias gariepinus', International Journal of Environmental Science and Technology, vol. 15, no. 10, pp. 2117-2128.View/Download from: Publisher's site
© 2017, Islamic Azad University (IAU). There is a paucity of information about the effects of environmental stressors on nutritional values in fish. This study investigated the effects of the organochlorine pesticide, butachlor, on key indicators of nutritional value in both diploid and triploid African catfish (Clarias gariepinus). Amino acids (AA), fatty acids (FA), and the proximate composition (protein, lipid, moisture, and ash content) in the white muscle of full-sibling juvenile fish were measured following a 21-day exposure to graded butachlor concentrations [mean measured: 26.3, 48.4, and 66.1 µg/L]. No significant differences in AAs, FAs, protein, lipid, moisture, or ash content were observed between unexposed diploid and triploid fish. In diploids, exposure to butachlor significantly altered the concentrations of some of the AAs and FAs, and protein content, when compared to the control group. In triploid fish, however, butachlor treatments had no effect on the AA or proximate composition, but significantly changed the concentration of two individual FAs in the muscle. Butachlor treatments showed fewer changes in the nutritional values of triploid fish. This research is the first to study the nutritional values in any polyploid animals following the exposure to a contaminant.
Scott, PD, Coleman, HM, Khan, S, Lim, R, McDonald, JA, Mondon, J, Neale, PA, Prochazka, E, Tremblay, LA, Warne, MSJ & Leusch, FDL 2018, 'Histopathology, vitellogenin and chemical body burden in mosquitofish (Gambusia holbrooki) sampled from six river sites receiving a gradient of stressors.', Science of the Total Environment, vol. 616-617, pp. 1638-1648.View/Download from: Publisher's site
There are over 40,000 chemical compounds registered for use in Australia, and only a handful are monitored in the aquatic receiving environments. Their effects on fish species in Australia are largely unknown. Mosquitofish (Gambusia holbrooki) were sampled from six river sites in Southeast Queensland identified as at risk from a range of pollutants. The sites selected were downstream of a wastewater treatment plant discharge, a landfill, two agricultural areas, and two sites in undeveloped reaches within or downstream of protected lands (national parks). Vitellogenin analysis, histopathology of liver, kidney and gonads, morphology of the gonopodium, and chemical body burden were measured to characterize fish health. Concentrations of trace organic contaminants (TrOCs) in water were analyzed by in vitro bioassays and chemical analysis. Estrogenic, anti-estrogenic, anti-androgenic, progestagenic and anti-progestagenic activities and TrOCs were detected in multiple water samples. Several active pharmaceutical ingredients (APIs), industrial compounds, pesticides and other endocrine active compounds were detected in fish carcasses at all sites, ranging from <4-4700ng/g wet weight, including the two undeveloped sites. While vitellogenin protein was slightly increased in fish from two of the six sites, the presence of micropollutants did not cause overt sexual endocrine disruption in mosquitofish (i.e., no abnormal gonads or gonopodia). A correlation between lipid accumulation in the liver with total body burden warrants further investigation to determine if exposure to low concentrations of TrOCs can affect fish health and increase stress on organs such as the liver and kidneys via other mechanisms, including disruption of non-sexual endocrine axes involved in lipid regulation and metabolism.
Zhao, C, Zhang, Y, Yang, S, Xiang, H, Sun, Y, Yang, Z, Yu, Q & Lim, RP 2018, 'Quantifying effects of hydrological and water quality disturbances on fish with food-web modeling', Journal of Hydrology, vol. 560, pp. 1-10.View/Download from: Publisher's site
© 2018 Elsevier B.V. Accurately delineating the effects of hydrological and water quality habitat factors on the aquatic biota will significantly assist the management of water resources and restoration of river ecosystems. However, current models fail to comprehensively consider the effects of multiple habitat factors on the development of fish species. In this study, a dynamic framework for river ecosystems was set up to explore the effects of multiple habitat factors in terms of hydrology and water quality on the fish community in rivers. To achieve this the biomechanical forms of the relationships between hydrology, water quality, and aquatic organisms were determined. The developing processes of the food web without external disturbance were simulated by 208 models, constructed using Ecopath With Ecosim (EWE). These models were then used to analyze changes in biomass (ΔB) of two representative fish species, Opsariichthys bidens and Carassius auratus, which are widely distributed in Asia, and thus have attracted the attention of scholars and stakeholders, due to the consequence of habitat alteration. Results showed that the relationship between the changes in fish biomass and key habitat factors can be expressed in a unified form. T-tests for the unified form revealed that the means of the two data sets of simulated and observed ΔB for these two fish species (O. bidens and C. auratus) were equal at the significance level of 5%. Compared with other ecological dynamic models, our framework includes theories that are easy to understand and has modest requirements for assembly and scientific expertise. Moreover, this framework can objectively assess the influence of hydrological and water quality variance on aquatic biota with simpler theory and little expertise. Therefore, it is easy to be put into practice and can provide a scientific support for decisions in ecological restoration made by river administrators and stakeholders across the world.
Rohlfs, AM, Williams, S, Rees, GN, Lim, RP, Werry, L & Mitrovic, SM 2018, 'Experimental dam releases stimulate respiration in an epilithic biofilm community', Hydrobiologia, vol. 820, no. 1, pp. 175-187.View/Download from: Publisher's site
© 2018, Springer International Publishing AG, part of Springer Nature. This study explored biofilm metabolism as a functional indicator of ecological responses to dissolved organic carbon and inorganic nutrients from managed dam releases. We hypothesised that the dam releases would stimulate epilithic biofilm community respiration (CR), and trigger a larger increase in biofilm CR relative to gross primary production (GPP). We predicted that biofilm respiration would be related to water column dissolved carbon and nutrient concentrations. Tiles colonised with epilithic biofilm were exposed to dam release waters in a stream-side mesocosm system that separated out the physical effects of flow velocity. Biofilm CR increased during two of three releases, and increases in CR were larger relative to GPP during all three releases. Biofilm CR was not linearly related to dissolved resources or abiotic environmental variables. These results show that managed dam releases can influence biofilm metabolism via a mechanism independent from the direct physical effects of increased flow velocity. This study provides new insights into the complex pathways through which managed dam releases may influence ecological processes. The stimulation of benthic CR through physical and chemical variations in dam water is a potential mechanism through which dam releases may influence biogeochemical processing and energy flow through the riverine food web.
Zhao, C, Yang, S, Liu, J, Liu, C, Hao, F, Wang, Z, Zhang, H, Song, J, Mitrovic, SM & Lim, RP 2018, 'Linking fish tolerance to water quality criteria for the assessment of environmental flows: A practical method for streamflow regulation and pollution control.', Water research, vol. 141, pp. 96-108.View/Download from: Publisher's site
The survival of aquatic biota in stream ecosystems depends on both water quantity and quality, and is particularly susceptible to degraded water quality in regulated rivers. Maintenance of environmental flows (e-flows) for aquatic biota with optimum water quantity and quality is essential for sustainable ecosystem services, especially in developing regions with insufficient stream monitoring of hydrology, water quality and aquatic biota. Few e-flow methods are available that closely link aquatic biota tolerances to pollutant concentrations in a simple and practical manner. In this paper a new method was proposed to assess e-flows that aimed to satisfy the requirements of aquatic biota for both the quantity and quality of the streamflow by linking fish tolerances to water quality criteria, or the allowable concentration of pollutants. For better operation of water projects and control of pollutants discharged into streams, this paper presented two coefficients for streamflow adjustment and pollutant control. Assessment of e-flows in the Wei River, the largest tributary of the Yellow River, shows that streamflow in dry seasons failed to meet e-flow requirements. Pollutant influx exerted a large pressure on the aquatic ecosystem, with pollutant concentrations much higher than that of the fish tolerance thresholds. We found that both flow velocity and water temperature exerted great influences on the pollutant degradation rate. Flow velocity had a much greater influence on pollutant degradation than did the standard deviation of flow velocity. This study provides new methods to closely link the tolerance of aquatic biota to water quality criteria for e-flow assessment. The recommended coefficients for streamflow adjustment and pollutant control, to dynamically regulate streamflow and control pollutant discharge, are helpful for river management and ecosystems rehabilitation. The relatively low data requirement also makes the method easy to use efficiently in developi...
Zhao, CS, Yang, ST, Sun, Y, Zhang, HT, Sun, CL, Xu, TR, Lim, RP & Mitrovic, SM 2018, 'Estimating river accommodation capacity for organic pollutants in data-scarce areas', Journal of Hydrology, vol. 564, pp. 442-451.View/Download from: Publisher's site
© 2018 Elsevier B.V. Globally, water quality degradation severely threatens the security of water resources. Understanding a river's capacity to accommodate pollutants (or water environmental capacity: WEC) can help efficiently protect rivers. However, the requirement for comprehensive ground-observed hydrological and water quality data in previous methods makes it difficult to estimate WEC in areas with limited ground observations. This paper proposes a new framework for WEC estimation in data-scarce areas based on remotely sensed skin water temperature and limited ground observations. Two new models were developed to calculate the two critical parameters for WEC estimation: water temperature, and integrated pollutant degradation coefficients (k). Images of ASTER Surface Kinetic Temperature (AST_08) 90 m grid product were used to retrieve water temperatures. The above results were subsequently used to calculate a river's capacity to accommodate pollutants, or WEC, in agriculturally dominated areas. The use of remote sensing techniques enables the methods to be applied over large spatial scales and to areas with limited ground observations. The application and testing of the framework in four rivers, including two Chinese rivers (the Huai and the Wei Rivers) and two Australian rivers (the Ovens and the Gwydir Rivers), suggest that the models performed well to calculate the real-time water temperature and the coefficient k based on limited ground-observations. Uncertainty analysis on water temperature calculated from remotely sensed land surface temperature and ground-observed meteorological air temperature suggests that remotely sensed water temperature had high concurrence with ground observations (RMSE = 3.08 °C with R2= 0.88), while the sparse-spatially distributed meteorological stations reduced the accuracy in estimating water temperature (RMSE = 4.39 °C with R2= 0.91). We found that the coefficient (k) increased with water temperature over different seasons...
Zhao, CS, Yang, ST, Zhang, HT, Liu, CM, Sun, Y, Yang, ZY, Zhang, Y, Dong, BE & Lim, RP 2017, 'Coupling habitat suitability and ecosystem health with AEHRA to estimate E-flows under intensive human activities', Journal of Hydrology, vol. 551, pp. 470-483.View/Download from: Publisher's site
© 2017 Elsevier B.V. Sustaining adequate environmental flows (e-flows) is a key principle for maintaining river biodiversity and ecosystem health, and for supporting sustainable water resource management in basins under intensive human activities. But few methods could correctly relate river health to e-flows assessment at the catchment scale when they are applied to rivers highly impacted by human activities. An effective method is presented in this study to closely link river health to e-flows assessment for rivers at the catchment scale. Key fish species, as indicators of ecosystem health, were selected by using the foodweb model. A multi-species-based habitat suitability model (MHSI) was improved, and coupled with dominance of the key fish species as well as the Index of Biological Integrity (IBI) to enhance its accuracy in determining the fish-preferred key hydrologic habitat variables related to ecosystem health. Taking 5964 fish samples and concurrent hydrological habitat variables as the basis, the combination of key variables of flow-velocity and water-depth were determined and used to drive the Adapted Ecological Hydraulic Radius Approach (AEHRA) to study e-flows in a Chinese urban river impacted by intensive human activities. Results showed that upstream urbanization resulted in abnormal river-course geomorphology and consequently abnormal e-flows under intensive human activities. Selection of key species based on the foodweb and trophic levels of aquatic ecosystems can reflect a comprehensive requirement on e-flows of the whole aquatic ecosystem, which greatly increases its potential to be used as a guidance tool for rehabilitation of degraded ecosystems at large spatial scales. These findings have significant ramifications for catchment e-flows assessment under intensive human activities and for river ecohealth restoration in such rivers globally.
Scott, PD, Coleman, HM, Colville, A, Lim, R, Matthews, B, McDonald, JA, Miranda, A, Neale, PA, Nugegoda, D, Tremblay, LA & Leusch, FDL 2017, 'Assessing the potential for trace organic contaminants commonly found in Australian rivers to induce vitellogenin in the native rainbowfish (Melanotaenia fluviatilis) and the introduced mosquitofish (Gambusia holbrooki).', Aquatic Toxicology, vol. 185, pp. 105-120.View/Download from: Publisher's site
In Australia, trace organic contaminants (TrOCs) and endocrine active compounds (EACs) have been detected in rivers impacted by sewage effluent, urban stormwater, agricultural and industrial inputs. It is unclear whether these chemicals are at concentrations that can elicit endocrine disruption in Australian fish species. In this study, native rainbowfish (Melanotaenia fluviatilis) and introduced invasive (but prevalent) mosquitofish (Gambusia holbrooki) were exposed to the individual compounds atrazine, estrone, bisphenol A, propylparaben and pyrimethanil, and mixtures of compounds including hormones and personal care products, industrial compounds, and pesticides at environmentally relevant concentrations. Vitellogenin (Vtg) protein and liver Vtg mRNA induction were used to assess the estrogenic potential of these compounds. Vtg expression was significantly affected in both species exposed to estrone at concentrations that leave little margin for safety (p<0.001). Propylparaben caused a small but statistically significant 3× increase in Vtg protein levels (p=0.035) in rainbowfish but at a concentration 40× higher than that measured in the environment, therefore propylparaben poses a low risk of inducing endocrine disruption in fish. Mixtures of pesticides and a mixture of hormones, pharmaceuticals, industrial compounds and pesticides induced a small but statistically significant increase in plasma Vtg in rainbowfish, but did not affect mosquitofish Vtg protein or mRNA expression. These results suggest that estrogenic activity represents a low risk to fish in most Australian rivers monitored to-date except for some species of fish at the most polluted sites.
Mowe, MAD, Porojan, C, Abbas, F, Mitrovic, SM, Lim, RP, Furey, A & Yeo, DCJ 2017, 'Corrigendum to "Rising temperatures may increase growth rates and microcystin production in tropical Microcystis species" [Harmful Algae 50 88-98].', Harmful algae, vol. 63, pp. 205-206.View/Download from: Publisher's site
Wood, RJ, Mitrovic, SM, Lim, RP & Kefford, BJ 2017, 'Chronic effects of atrazine exposure and recovery in freshwater benthic diatoms from two communities with different pollution histories', AQUATIC TOXICOLOGY, vol. 189, pp. 200-208.View/Download from: Publisher's site
Hamilton, LA, Tremblay, LA, Northcott, GL, Boake, M & Lim, RP 2016, 'The impact of variations of influent loading on the efficacy of an advanced tertiary sewage treatment plant to remove endocrine disrupting chemicals', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 560, pp. 101-109.View/Download from: Publisher's site
Mowe, MAD, Abbas, F, Porojan, C, Mitrovic, SM, Lim, RP, Furey, A & Yeo, DCJ 2016, 'Roles of nitrogen and phosphorus in growth responses and toxin production (using LC-MS/MS) of tropical Microcystis ichthyoblabe and M. flos-aquae', Journal of Applied Phycology.View/Download from: Publisher's site
© 2015 Springer Science+Business Media Dordrecht In experiments investigating nutrient effects on tropical Microcystis, increasing nitrogen and phosphorus concentrations were found to have a significant positive effect on maximum cell yields of two strains of Microcystis ichthyoblabe (from Lower Peirce and Tengeh Reservoirs) and one strain of Microcystis flos-aquae isolated (Lower Peirce Reservoir) from Singapore. However, only increasing nitrogen concentration had a positive effect on growth rates of M. ichthyoblabe and M. flos-aquae from Lower Peirce Reservoir. MC-RR and MC-LR were produced by all three strains with MC-RR being the dominant variant. Phosphorus played an important role in MC production with increases in phosphorus from medium to high concentrations leading to decreases in MC-RR cell quotas for all three strains at the two highest nitrogen levels tested. The different growth and toxin production responses between M. ichthyoblabe strains could be due to location-specific differences.
Wood, RJ, Mitrovic, SM, Lim, RP & Kefford, BJ 2016, 'How benthic diatoms within natural communities respond to eight common herbicides with different modes of action', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 557, pp. 636-643.View/Download from: Publisher's site
Wood, RJ, Mitrovic, SM, Lim, RP & Kefford, BJ 2016, 'The influence of reduced light intensity on the response of benthic diatoms to herbicide exposure.', Environmental Toxicology and Chemistry, vol. 35, no. 9, pp. 2252-2260.View/Download from: Publisher's site
Herbicide pollution events in aquatic ecosystems often co-occur with increased turbidity and reduced light intensity. It is therefore important to determine whether reduced light intensity can influence herbicide toxicity, especially to primary producers such as benthic diatoms. Benthic diatoms collected from four rivers were exposed to herbicides in 48 h rapid toxicity tests under high light (100 µmol m(-2) s(-1) ) and low light (20 µmol m(-2) s(-1) ) intensities. The effects of two herbicides (atrazine and glyphosate) were assessed on 26 freshwater benthic diatom taxa. There was no significant interaction of light and herbicide effects at the community level or on the majority (22 of 26) of benthic diatom taxa. This indicates that low light levels will likely have only a minor influence on the response of benthic diatoms to herbicides. This article is protected by copyright. All rights reserved.
Patra, RW, Chapman, JC, Lim, RP, Gehrke, PC & Sunderam, RM 2015, 'Interactions between water temperature and contaminant toxicity to freshwater fish', ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, vol. 34, no. 8, pp. 1809-1817.View/Download from: Publisher's site
Rahman, MA, Hogan, B, Duncan, E, Doyle, C, Rahman, MM, Nguyen, TV, Lim, RP, Maher, W, Naidu, R, Krassoi, R, Vigneswaran, S & Hassler, C 2015, 'Ecotoxicological Effects of an Arsenic Remediation Method on Three Freshwater Organisms-Lemna disperma, Chlorella sp CE-35 and Ceriodaphnia cf. dubia', WATER AIR AND SOIL POLLUTION, vol. 226, no. 12.View/Download from: Publisher's site
Mowe, MAD, Mitrovic, SM, Lim, RP, Furey, A & Yeo, DCJ 2015, 'Tropical cyanobacterial blooms: a review of prevalence, problem taxa, toxins and influencing environmental factors', Journal of Limnology, vol. 73, no. 2, pp. 205-224.View/Download from: Publisher's site
Mowe, MAD, Porojan, C, Abbas, F, Mitrovic, SM, Lim, RP, Furey, A & Yeo, DCJ 2015, 'Rising temperatures may increase growth rates and microcystin production in tropical Microcystis species', HARMFUL ALGAE, vol. 50, pp. 88-98.View/Download from: Publisher's site
Zhao, CS, Yang, ST, Liu, CM, Dou, TW, Yang, ZL, Yang, ZY, Liu, XL, Xiang, H, Nie, SY, Zhang, JL, Mitrovic, SM, Yu, Q & Lim, RP 2015, 'Linking hydrologic, physical and chemical habitat environments for the potential assessment of fish community rehabilitation in a developing city', JOURNAL OF HYDROLOGY, vol. 523, pp. 384-397.View/Download from: Publisher's site
Zhao, CS, Yang, ST, Xiang, H, Liu, CM, Zhang, HT, Yang, ZL, Zhang, Y, Sun, Y, Mitrovic, SM, Yu, Q & Lim, RP 2015, 'Hydrologic and water-quality rehabilitation of environments for suitable fish habitat', JOURNAL OF HYDROLOGY, vol. 530, pp. 799-814.View/Download from: Publisher's site
Rahman, MA, Hogan, B, Duncan, E, Doyle, C, Krassoi, R, Rahman, MM, Naidu, R, Lim, RP, Maher, W & Hassler, C 2014, 'Toxicity of arsenic species to three freshwater organisms and biotransformation of inorganic arsenic by freshwater phytoplankton (Chlorella sp. CE-35)', Ecotoxicology And Environmental Safety, vol. 106, pp. 126-135.View/Download from: Publisher's site
In the environment, arsenic (As) exists in a number of chemical species, and arsenite (AsIII) and arsenate (AsV) dominate in freshwater systems. Toxicity of As species to aquatic organisms is complicated by their interaction with chemicals in water such as phosphate that can influence the bioavailability and uptake of AsV. In the present study, the toxicities of AsIII, AsV and dimethylarsinic acid (DMA) to three freshwater organisms representing three phylogenetic groups: a phytoplankton (Chlorella sp. strain CE-35), a floating macrophyte (Lemna disperma) and a cladoceran grazer (Ceriodaphnia cf. dubia), were determined using acute and growth inhibition bioassays (EC50) at a range of total phosphate (TP) concentrations in OECD medium. The EC50 values of AsIII, AsV and DMA were 27±10, 1.15±0.04 and 19±3 mg L-1 for Chlorella sp. CE-35; 0.57±0.16, 2.3±0.2 and 56±15 mg L-1 for L. disperma, and 1.58±0.05, 1.72±0.01 and 5.9±0.1 mg L-1 for C. cf. dubia, respectively. The results showed that AsIII was more toxic than AsV to L. disperma; however, AsV was more toxic than AsIII to Chlorella sp. CE-35. The toxicities of AsIII and AsV to C. cf. dubia were statistically similar (p>0.05). DMA was less toxic than iAs species to L. disperma and C. cf. dubia, but more toxic than AsIII to Chlorella sp. CE-35. The toxicity of AsV to Chlorella sp. CE-35 and L. disperma decreased with increasing TP concentrations in the growth medium. Phosphate concentrations did not influence the toxicity of AsIII to either organism. Chlorella sp. CE-35 showed the ability to reduce AsV to AsIII, indicating a substantial influence of phytoplankton on As biogeochemistry in freshwater aquatic systems.
Rahman, MA, Rahman, MM, Reichman, SM, Lim, RP & Naidu, R 2014, 'Arsenic speciation in Australian-grown and imported rice on sale in Australia: Implications for human health risk', Journal of Agricultural and Food Chemistry, vol. 62, no. 25, pp. 6016-6024.View/Download from: Publisher's site
Rice is an important route of arsenic (As) exposure to human, especially the populations with rice-based diets. Human health risk of As varies greatly with rice variety and country of origin. The purpose of the present study was to determine total and speciated As in Australian grown and imported rice on sale in Australia to assess their health risk to the consumers. The total As (tAs) concentrations in Australian grown organic brown, medium grain brown, and organic white rice were 438±23, 287±03 and 283±18 µg kg-1 dry weight (d. wt.), respectively. In Bangladeshi, Indian, Pakistani, and Thai rice imported and on sale in Australia, tAs concentrations were 56±05, 92±10, 82±06 and 172±24 µg kg-1, respectively. Asian rice contained mainly inorganic As (iAs; 86-99%), while 18-26% of the tAs in Australian grown rice was dimethylarsinic acid (DMA). Relatively higher concentration of tAs in Australian grown rice than imported rice of Asian origin suggests that Australian rice may be a health risk for the consumers. It was estimated that Australian grown organic brown rice can contribute up to 98% of the FAO/WHO recommended maximum tolerable daily intake limit of iAs (2.1 µg kg-1 body wt. day-1) for Asian immigrants. However, other Australian consumers including the European immigrants unlikely to have health risk of As from rice diets due to their lower rice consumption rates than the Asian immigrants. The risk assessment showed that imported rice on sale in Australia was likely to pose lower health risk to consumers than Australian grown rice.
Rahman, MA, Rahman, MM, Reichman, SM, Lim, RP & Naidu, R 2014, 'Heavy metals in Australian grown and imported rice and vegetables on sale in Australia: Health hazard', Ecotoxicology And Environmental Safety, vol. 100, pp. 53-60.View/Download from: Publisher's site
Dietary exposure to heavy metals is a matter of concern for human health risk through the consumption of rice, vegetables and other major foodstuffs. In the present study, we investigated concentrations of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) in Australian grown and imported rice and vegetables on sale in Australia. The mean concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn in Australian grown rice were 7.5 mg kg1, 21 mg kg1, 144 mg kg1, 2.9 mg kg1, 24.4 mg kg1, 166 mg kg1, 375 mg kg1, and 17.1 mg kg1 dry weight (d. wt.), respectively. Except Cd, heavy metal concentrations in Australian grown rice were higher than Bangladeshi rice on sale in Australia. However, the concentrations of Cd, Cr, Cu, and Ni in Indian rice on sale in Australia were higher than Australian grown rice. The concentrations of Cu and Ni in Vietnamese rice, and that of Cd, Cr, Cu, Ni, and Pb in Thai rice on sale in Australia were also higher than Australian grown rice. Heavy metal concentrations in Pakistani rice on sale in Australia were substantially lower than that in Australian grown rice. In Australian grown rice varieties, the concentrations of heavy metals were considerably higher in brown rice varieties than white rice varieties, indicating Australian brown rice as a potential source of dietary heavy metals for Australian consumers. The mean concentrations of heavy metals in Australian grown and Bangladeshi vegetables on sale in Australia were also determined. Some of the Australian grown and Bangladeshi vegetables contained heavy metals higher than Australian standard maximum limits indicating them as potential sources of dietary heavy metals for Australian consumers. Further investigation is required to estimate health risks of heavy metals from rice and vegetables consumption for Australian consumers.
Scott, PD, Bartkow, M, Blockwell, SJ, Coleman, HM, Khan, SJ, Lim, R, McDonald, JA, Nice, H, Nugegoda, D, Pettigrove, V, Tremblay, LA, Warne, MSJ & Leusch, FDL 2014, 'A National Survey of Trace Organic Contaminants in Australian Rivers', Journal of Environment Quality, vol. 43, no. 5, pp. 1702-1702.View/Download from: Publisher's site
Scott, PD, Bartkow, M, Blockwell, SJ, Coleman, HM, Khan, SJ, Lim, R, McDonald, JA, Nice, H, Nugegoda, D, Pettigrove, V, Tremblay, LA, Warne, MSJ & Leusch, FDL 2014, 'An assessment of endocrine activity in Australian rivers using chemical and in vitro analyses', Environmental Science and Pollution Research, vol. 21, no. 22, pp. 12951-12967.View/Download from: Publisher's site
Chen, Z, Ngo, H, Guo, W, Lim, RP, Wang, XC, O'Halloran, K, Listowski, A, Corby, N & Miechel, C 2014, 'A comprehensive framework for the assessment of new end uses in recycled water schemes', The Science of the Total Environment, vol. 470-471, pp. 44-52.View/Download from: Publisher's site
Nowadays, recycled water has provided sufficient flexibility to satisfy short-term freshwater needs and increase the reliability of long-term water supplies in many water scarce areas, which becomes an essential component of integrated water resources management. However, the current applications of recycled water are still quite limited that are mainly associated with non-potable purposes such as irrigation, industrial uses, toilet flushing and car washing. There is a large potential to exploit and develop new end uses of recycled water in both urban and rural areas. This can greatly contribute to freshwater savings, wastewater reduction and water sustainability. Consequently, the paper identified the potentials for the development of three recycled water new end uses, household laundry, livestock feeding and servicing, and swimming pool, in future water use market. To validate the strengths of these new applications, a conceptual decision analytic framework was proposed. This can be able to facilitate the optional management strategy selection process and thereafter provide guidance on the future end use studies within a larger context of the community, processes, and models in decision-making. Moreover, as complex evaluation criteria were selected and taken into account to narrow down the multiple management alternatives, the methodology can successfully add transparency, objectivity and comprehensiveness to the assessment. Meanwhile, the proposed approach could also allow flexibility to adapt to particular circumstances of each case under study.
Chen, Z, Ngo, H, Guo, W, Pham, N, Lim, RP, Wang, XC, Miechel, C, O'Halloran, K, Listowski, A & Corby, N 2014, 'A new optional recycled water pre-treatment system prior to use in the household laundry', The Science of the Total Environment, vol. 476-447, pp. 513-521.View/Download from: Publisher's site
With a constantly growing population, water scarcity becomes the limiting factor for further social and economic growth. To achieve a partial reduction in current freshwater demands and lessen the environmental loadings, an increasing trend in the water market tends to adopt recycled water for household laundries as a new recycled water application. The installation of a small pre-treatment unit for water purification can not only further improve the recycled water quality, but also be viable to enhance the public confidence and acceptance level on recycled water consumption. Specifically, this paper describes column experiments conducted using a 550 mm length bed of zeolite media as a one-dimensional flow reactor. The results show that the zeolite filter system could be a simple low-cost pre-treatment option which is able to significantly reduce the total hardness level of recycled water via effective ion exchange. Additionally, depending on the quality of recycled water required by end users, a new by-pass controller using a three-level operation switching mechanism is introduced. This approach provides householders sufficient flexibility to respond to different levels of desired recycled water quality and increase the reliability of long-term system operation. These findings could be beneficial to the smooth implementation of new end uses and expansion of the potential recycled water market. The information could also offer sound suggestions for future research on sustainable water management and governance.
Korbel, KL, Hancock, P, Serov, P, Lim, RP & Hose, GC 2013, 'Groundwater Ecosystems Vary With Land Use Across A Mixed Agricultural Landscape', Journal of Environmental Quality, vol. 42, no. 2, pp. 380-390.View/Download from: Publisher's site
Changes in surface land use may threaten groundwater quality and ecosystem integrity, particularly in shallow aquifers where links between groundwater and surface activities are most intimate. In this study we examine the response of groundwater ecosystem to agricultural land uses in the shallow alluvial aquifer of the Gwydir River valley, New South Wales, Australia. We compared groundwater quality and microbial and stygofauna assemblages among sites under irrigated cropping, non-irrigated cropping and grazing land uses. Stygofauna abundance and richness was greatest at irrigated sites, with the composition of the assemblage suggestive of disturbance. Microbial assemblages and water quality also varied with land use. Our study demonstrates significant differences in the composition of groundwater ecosystems in areas with different surface land use, and highlights the utility of groundwater biota for biomonitoring, particularly in agricultural landscapes.
Korbel, KL, Lim, RP & Hose, GC 2013, 'An inter-catchment comparison of groundwater biota in the cotton-growing region of north-western New South Wales', Crop and Pasture Science, vol. 64, no. 11-12, pp. 1195-1208.View/Download from: Publisher's site
Groundwater is essential to crop production in many parts of the world, and the provision of clean groundwater is dependent on healthy groundwater ecosystems. To understand better the functioning of groundwater ecosystems, it is necessary to understand h
Phyu, YL, Palmer, CG, Warne, MS, Dowse, R, Mueller, S, Chapman, JC, Hose, GC & Lim, RP 2013, 'Assessing The Chronic Toxicity Of Atrazine, Permethrin, And Chlorothalonil To The Cladoceran Ceriodaphnia Cf. Dubia In Laboratory And Natural River Water', Archives Of Environmental Contamination And Toxicology, vol. 64, no. 3, pp. 419-426.View/Download from: Publisher's site
The majority of ecotoxicological data are generated from standard laboratory-based experiments with organisms exposed in nonflowing systems using highly purified water, which contains very low amounts of dissolved organic matter and suspended particulates. However, such experimental conditions are not ecologically relevant. Thus, there is a need to develop more realistic approaches to determining toxicity, including both lethal and sublethal effects. This research provides information on the effect of natural water constituents, such as suspended particulates and dissolved organic matter, in river water (RW) on the chronic toxicity (7-day reproductive impairment) of the pesticides atrazine, chlorothalonil, and permethrin to the freshwater cladoceran Ceriodaphnia cf. dubia. Standard bioassays were conducted under standard laboratory and more environmentally realistic conditions (using RW). The 7-day IC25 (reproduction impairment) values of atrazine, chlorothalonil, and permethrin to C. cf. dubia ranged from 862.4 to >1000, 51.3 to 66.4, and 0.19 to 0.23 µg/L, respectively. Using the Globally Harmonized System of Classification and Labelling of Chemicals, atrazine is classified as moderately to highly toxic, whereas permethrin and chlorothalonil were both highly toxic. The presence of dissolved organic matter and suspended particles in natural RW did not significantly (p > 0.05) change the toxicity of any of the pesticides to C. cf. dubia compared with that tested in laboratory water (LW). For the tested pesticides, toxicity testing in LW provided an adequate estimate of the hazard posed.
Rahman, MA, Hasegawa, H, Rahman, MM, Maki, T & Lim, RP 2013, 'Effect of Iron (Fe2+) Concentration in Soil on Arsenic Uptake in Rice Plant (Oryza sativa L.) when Grown with Arsenate [As(V)] and Dimethylarsinate (DMA)', WATER AIR AND SOIL POLLUTION, vol. 224, no. 7.View/Download from: Publisher's site
Rahman, MA, Hasegawa, H & Lim, RP 2012, 'Bioaccumulation, biotransformation and trophic transfer of arsenic in the aquatic food chain', Environmental Research, vol. 116, pp. 118-135.View/Download from: Publisher's site
The occurrence, distribution, speciation, and biotransformation of arsenic in aquatic environment (marine and freshwater) have been studied extensively by several research groups during last couple of decades. However, most of those studies have been conducted in marine waters, and the results are available in a number of reviews. Speciation, bioaccumulation, and biotransformation of arsenic in freshwaters have been studied in recent years. Although inorganic arsenic (iAs) species dominates in both marine and freshwaters, it is biotransformed to methyl and organoarsenic species by aquatic organisms. Phytoplankton is considered as a major food source for the organisms of higher trophic levels in the aquatic food chain, and this autotrophic organism plays important role in biotransformation and distribution of arsenic species in the aquatic environment. Bioaccumulation and biotransformation of arsenic by phytoplankton, and trophic transfer of arsenic in marine and freshwater food chains have been important concerns because of possible human health effects of the toxic metalloid from dietary intake. To-date, most of the studies on arsenic biotransformation, speciation, and trophic transfer have focused on marine environments; little is known about these processes in freshwater systems. This article has been reviewed the bioaccumulation, biotransformation, and trophic transfer of arsenic in marine and freshwater food chain.
Cortez, DP, Growns, I, Mitrovic, S & Lim, RP 2012, 'Effects Of A Gradient In River Regulation On The Longitudinal Trends In Water Quality And Benthic Algal And Macroinvertebrate Assemblages In The Hunter River, Australia', Marine and Freshwater Research, vol. 63, no. 6, pp. 494-504.View/Download from: Publisher's site
River regulation impacts lotic ecosystem processes; however, the effect of a gradient of regulation on these attributes has rarely been studied. This study examined the effects of a river regulation gradient on longitudinal trends in water quality and be
Davie, AW, Mitrovic, S & Lim, RP 2012, 'Succession and accrual of benthic algae on cobbles of an upland river following scouring', Inland Waters, vol. 2, no. 2, pp. 89-100.View/Download from: Publisher's site
Flow releases from dams can be used to scour benthic algae, simulating the effects of natural spates and maintaining benthic algae in an early successional stage for increased grazer palatability. The timing of releases needs to consider the natural periodicity of flow events and the speed of regrowth and community succession changes. We studied benthic algal regrowth and succession using manipulative field experiments during summer and winter in the upland regulated Severn River, New South Wales, Australia. Benthic algal biomass accrual as chlorophyll a and community changes were determined after artificially scoured cobbles were returned to the river. In summer, algal biomass and diversity on scoured cobbles took 2 weeks to return to levels similar to reference cobbles and 5 weeks in winter. Chlorophyll a during summer was initially 0.24 ± 0.06 mg m-2 on scoured cobbles, but by day 16 had increased to 9.74 ± 1.97 mg m-2 and was no longer significantly different from reference cobbles. In winter, chlorophyll a was initially 0.47 ± 0.13 mg m-2 on scoured cobbles, but by day 37 had increased to 44.7 ± 10.9 mg m-2 and was no longer significantly different from reference cobbles. Peak chlorophyll a accrual during summer and winter was 1.64 and 2.63 mg m-2 d-1, respectively. Early succession in both experiments was dominated by diatoms such as Cocconeis, Synedra, and Fragilaria. A proliferation of the filamentous green alga Stigeoclonium was indicative of a late succession community. The implications for flow management based on resetting of benthic algae by scouring in riffle reaches of rivers are discussed.
Mohammed Abdul, J, Colville, AE, Lim, RP, Vigneswaran, S & Kandasamy, JK 2012, 'Use of duckweed (Lemna disperma) to assess the phytotoxicity of the products of Fenton oxidation of metsulfuron methyl', Ecotoxicology And Environmental Safety, vol. 83, pp. 89-95.View/Download from: Publisher's site
Because of pressure on water supplies world-wide, there is increasing interest in methods of remediating contaminated ground waters. However, with some remediation processes, the breakdown products are more toxic than the original contaminant. Organic matter and salinity may also influence degradation efficiency. This study tested the efficiency of Fenton oxidation in degrading the sulfonylurea herbicide metsulfuron methyl (MeS), and tested the reaction products for phytotoxicity with the Lemna (duckweed) bioassay. The efficiency of degradation by Fentonâs reagent (Fe2Ã¾ Â¼0.09 mM; H2O2Â¼1.76mM, 4 h) decreased with increasing initial MeS concentration, from 98% with 5 mg/L MeS, to 63% with 70 mg/L MeS. Addition of NaCl (10 mM) and organic matter (humic acid at 0.2 and 2.0 mg C/L as Total Organic Carbon) reduced the efficiency of degradation at low initial MeS concentrations (5 and 10mg/L), but had no effect at high concentrations. The residual Fentonâs reagent after Fentonâs oxidation was toxic to Lemna. After removal of residual iron and H2O2, the measured toxicity to Lemna in the treated samples could be explained by the concentrations of MeS as measured by HPLC/UV detection, so there was no evidence of additional toxicity or amelioration due to the by-products or formulation materials.
Phyu, YL, Palmer, CG, Warne, MS, Hose, GC, Chapman, JC & Lim, RP 2011, 'A Comparison Of Mixture Toxicity Assessment: Examining The Chronic Toxicity Of Atrazine, Permethrin And Chlorothalonil In Mixtures To Ceriodaphnia Cf. Dubia', Chemosphere, vol. 85, no. 10, pp. 1568-1573.View/Download from: Publisher's site
Pesticides predominantly occur in aquatic ecosystems as mixtures of varying complexity, yet relatively few studies have examined the toxicity of pesticide mixtures. Atrazine, chlorothalonil and permethrin are widely used pesticides that have different mo
Leusch, F, De Jager, C, Levi, Y, Lim, RP, Puijker, L, Sacher, F, Tremblay, L, Wilson, V & Chapman, HD 2010, 'Comparison Of Five In Vitro Bioassays To Measure Estrogenic Activity In Environmental Waters', Environmental Science & Technology, vol. 44, no. 10, pp. 3853-3860.View/Download from: Publisher's site
Bioassays are well established in the pharmaceutical industry and single compound analysis, but there is still uncertainty about their usefulness in environmental monitoring. We compared the responses of five bioassays designed to measure estrogenic acti
Rawson, CA, Lim, RP, Tremblay, L, Warne, MS, Ying, G, Laginestra, E & Chapman, JC 2010, 'Benthic Macroinvertebrate Assemblages In Remediated Wetlands Around Sydney, Australia', Ecotoxicology, vol. 19, no. 8, pp. 1589-1600.View/Download from: Publisher's site
To investigate potential high organisational level impacts of persistent organic pollution in the wetlands in the Sydney Olympic Park (SOP) remediated site, the benthic macroinvertebrate assemblages of seven wetlands within SOP and two off-site reference wetlands were examined.
Thomas, CR, Warne, MSJ, Hose, GC & Lim, RP 2010, 'River water and sediment reduce the toxicity of deltamethrin to paratya Australiensis', Australasian Journal of Ecotoxicology, vol. 16, no. 1, pp. 9-16.
Deltamethrin is a pyrethroid insecticide used extensively to control cotton pests in Australia and worldwide. Deltamethrin readily binds to organic and particulate matter in the environment, thereby reducing its bioavailability and toxicity, yet most toxicity data come from studies using clean, organic matter-free water that were conducted under conditions that differ greatly from those in the turbid rivers of the cotton-growing regions of Australia. The aim of this study was to assess the toxicity of deltamethrin to the native glass shrimp, Paratya australiensis, and to consider the role of suspended and bottom sediment in the amelioration of deltamethrin toxicity. We conducted a series of acute single-species toxicity tests in the laboratory and in the field in the Namoi-Gwydir cotton region of northwest New South Wales, Australia. The toxicity of deltamethrin was significantly (p≤0.05) reduced in river water compared with that in laboratory water in laboratory but not field-based tests. The toxicity of deltamethrin in river water was further reduced with the addition of bottom sediment. Despite reductions in toxicity in natural waters, deltamethrin remained highly toxic (i.e. 60-h EC50 values <200 ng/L) to P. australiensis, and thus further investigation of the hazard of deltamethrin is warranted.
Patra, R, Chapman, JC, Lim, RP, Gehrke, P & Sunderam, R 2009, 'Effects Of Temperature On Ventilatory Behavior Of Fish Exposed To Sublethal Concentrations Of Endosulfan And Chlorpyrifos', Environmental Toxicology and Chemistry, vol. 28, no. 10, pp. 2182-2190.View/Download from: Publisher's site
The ventilation amplitude and frequency of silver perch Bidyanus bidyanus, and the ventilation frequency of rainbow fish Melanotaenia duboulayi and rainbow trout Oncorhynchus mykiss, were determined at different temperatures upon exposure to endosulfan and chlorpyrifos, respectively. Silver perch and rainbow fish were tested at 15, 20, 25, 30, and 35 degrees C, while rainbow trout was tested at 10, 15, 20, and 25 degrees C. Although some trend of increasing amplitudes with increasing temperature was evident; there was no significant temperature response of ventilation frequency rates over time in silver perch pre-exposed to 10 mu g L-1 endosulfan for 18 h. The rate of ventilation frequency of rainbow fish pre-exposed to 200 mu g L-1 of chlorpyrifos for 96 h was lower in treatments than in the control at 15 degrees C. However, between 20 and 35 degrees C, rates were significantly higher in the treatments than those of the control. In rainbow trout pre-exposed to 100 mu g L-1 of chlorpyrifos, the rates of frequency were significantly lower than those of controls in temperatures between 10 and 20 degrees C but higher at 25 degrees C. The amplitude of silver perch seemed to increase with the increase in temperature; however, the corresponding temperature quotient values at various temperature regimes and over exposure time showed no significant differences. The ventilation frequency of rainbow fish and rainbow trout significantly increased at the higher test temperatures, and their corresponding temperature quotient values for both fish also increased at the elevated temperatures.
Rawson, CA, Tremblay, L, Warne, MS, Ying, G, Kookana, RS, Laginestra, E, Chapman, JC & Lim, RP 2009, 'Bioactivity of POPs and their effects in mosquitofish in Sydney Olympic Park, Australia', Science of the Total Environment, vol. 407, no. 12, pp. 3721-3730.View/Download from: Publisher's site
The site of the 2000 Olympic Games (Sydney Olympic Park (SOP), Sydney, Australia) was contaminated by persistent organic pollutants (POPs) prior to remediation in the 1990s. This study investigates the bioactivity of POPs in the sediment and water of wetlands across SOP by in vitro 2,3,7,8-TCDD equivalence (TCDDeq) measurement (H4IIE cell line bioassay). Further, it examines whether disturbance of these sediments is likely to mobilise ligands for this receptor into the water column.
Ying, G, Rawson, CA, Kookana, RS, Peng, P, Warne, MS, Tremblay, L, Laginestra, E, Chapman, JC & Lim, RP 2009, 'Contamination And Screening Level Toxicity Of Sediments From Remediated And Unremediated Wetlands Near Sydney, Australia', Environmental Toxicology and Chemistry, vol. 28, no. 10, pp. 2052-2060.View/Download from: Publisher's site
The present study assessed contamination and toxicity of sediments from seven remediated and remnant wetland sites within Sydney Olympic Park, Australia, and four unremediated sites adjacent to its boundary using chemical analysis and a luminescent bacterial biosensor assay (Escherichia coli). Concentrations of metals (Pb, Cr, Cu, Ni, Zn, Cd, and As) and persistent organic chemicals (DDT and its metabolites, dichlorodiphenyldichloroethane and dichlorodiphenyldichloroethylene; polycyclic aromatic hydrocarbons; polychlorinated biphenyls; and polychlorinated dibenzo-p-dioxins and dibenzofurans) in sediments and their pore-water samples were determined. Zinc concentrations were the highest of the metals in the sediments (84-618 mg/kg), and at eight sites, metal concentrations in sediments exceeded the Australian ecological trigger values for Pb, Zn, and Ni. Concentrations of organic contaminants in the sediments exceeded the trigger values at all 11 sites for DDTs, at 6 sites for polycyclic aromatic hydrocarbons, and 5 sites for polychlorinated biphenyls. Sediment samples from the four unremediated sites outside the Sydney Olympic Park had dioxin concentrations greater than 200 pg (toxic equivalency per gram). The same four sites were identified as contaminated in pore-water toxicity tests with the luminescent biosensor, generally consistent with the bioavailable fractions of the contaminants (pore-water and Tenax (R) extraction data), as well as dioxin levels, in the sediments. Preliminary toxicity identification and evaluation tests of the pore water from the four sites outside the park demonstrated that organic contaminants were the main cause of toxicity to E. coli, with no evidence that metals contributed to the toxicity of the pore water.
Ying, G-G, Rawson, CA, Kookana, RS, Warne, MSJ, Peng, P-A, Li, X-M, Laginestra, E, Tremblay, LA, Chapman, JC & Lim, RP 2009, 'Distribution of inorganic and organic contaminants in sediments from Sydney Olympic Park and the surrounding Sydney metropolitan area', JOURNAL OF ENVIRONMENTAL MONITORING, vol. 11, no. 9, pp. 1687-1696.View/Download from: Publisher's site
Ngo, H, Chuang, Y, Guo, W, Ho, D, Pham, N, Johnston, AJ, Lim, RP & Listowski, A 2009, 'Resident's strategy survey on a new end use of recycled water in Australia', Desalination and Water Treatment, vol. 11, no. 1-3, pp. 93-97.View/Download from: Publisher's site
The concept of using recycled water for washing machine was introduced as a new end use. As there is a noticeable lack social research in understanding the general public perceptions of this application, the residents strategy survey was carried out at some selective suburbs in Sydney with demographically based signifi cant differences of general, gender, age, education, and property style and ownership. The survey indicates that the majority in the community considers the use of recycled water for washing machine is indispensable in view of continuing drought and the associated water shortages. Given safety assurance and demonstration, recycled water for washing machine has a considerable proportion within the responses. The general level of knowledge in community clearly understand that recycled water is more environmentally friendly option, whereas from cleanness and public health point of view, higher quality water is required to be reused in washing machine. Moreover, the residents reckon to have a small unit for pre-treatment (point of use) before recycled water entering washing machines might assure the quality and safety. The survey also shows the major concerns for a resident to use recycled water for washing machine are public health, water cleanness and washing machine durability.
Phyu, YL, Warne, MS & Lim, RP 2008, 'Assessing the biological relevance of exposing freshwater organisms to atrazine and molinate in environmetally realistic exposure test systems', Environmental Toxicology And Chemistry, vol. 27, no. 2, pp. 420-424.View/Download from: Publisher's site
Assessing the toxicity of chemicals in treated laboratory water may not accurately represent the toxicity of chemicals in natural aquatic systems. In natural water, dissolved organic matter, suspended particulate matter, and sediment play key roles in the sorption of contaminants from the water. Our previously published series of papers illustrated that the presence of sediment in aquatic toxicity testing systems significantly (p < 0.05) reduced the bioavailability of the herbicides atrazine and molinate to five Australian freshwater organisms. It is not clear whether the reduced bioavailability means that the trigger values (TVs) in the current Australian and New Zealand water quality guidelines, which are calculated using toxicity data from water-only toxicity tests, provide appropriate environmental protection. Several new sets of TVs were derived in the present study and were compared to each other and to the current Australian and New Zealand TVs for atrazine and molinate. The current Australian and New Zealand TVs for atrazine and molinate provided appropriate protection to Australian freshwater species. Australian freshwater species have a sensitivity distribution similar to those of overseas species to atrazine and molinate
Rawson, CA, Lim, RP & Warne, MS 2008, 'Skeletal morphology and maturation of male Gambusia holbrooki exposed to sewage treatment plant effluent', Ecotoxicology And Environmental Safety, vol. 70, no. 3, pp. 453-461.View/Download from: Publisher's site
Sewage effluent has been identified as a major source of endocrine disrupting chemicals (EDCs) in the aquatic environment. The modified hemal spines (modified skeletal structures important in reproduction) of mosquitofish, Gambusia spp. have been shown t
Thomas, CM, Hose, GC, Warne, MS & Lim, RP 2008, 'Effects of river water and salinity on the toxicity of deltamethrin to freshwater shrimp, cladoceran, and fish', Archives Of Environmental Contamination And Toxicology, vol. 55, no. 4, pp. 610-618.View/Download from: Publisher's site
Deltamethrin is a pyrethroid insecticide used extensively to control invertebrate pests on cotton and other crops. It is acutely toxic to nontarget aquatic organisms, but existing toxicity data are mostly from toxicity tests using purified laboratory wat
Colville, AE, Jones, PM, Pablo, F, Krassoi, R, Hose, GC & Lim, RP 2008, 'Effects of chlorpyrifos on macroinvertebrate communities in coastal stream mesocosms', Ecotoxicology, vol. 17, no. 3, pp. 173-180.View/Download from: Publisher's site
This study measured the effects of a single pulse of chlorpyrifos at nominal concentrations of 1 and 10 mu g/l on the macroinvertebrate community structure of a coastal stream mesocosm system. Analysis of data using Principal Response Curves (PRC) and Monte Carlo tests showed significant changes in the treated stream mesocosms relative to that of the controls. These changes in the macroinvertebrate assemblages occurred within 6 h, and persisted for at least 124 days after dosing. Significant community-level effects were detected at the lowest concentration on days 2 and 16 post-dosing, giving a no-observed effect concentration (NOECcommunity) of 1.2 mu g/l (measured). The mayflies Atalophlebia sp. and Koorrnonga sp., Chironomidae and Acarina were all sensitive to chlorpyrifos and decreased in abundance in treated mesocosms after dosing. The fauna of these coastal stream mesocosms showed similar sensitivity to chlorpyrifos with that of other reported studies, but there was no evidence of recovery after 124 days.
Pablo, F, Krassoi, R, Jones, PR, Colville, AE, Hose, GC & Lim, RP 2008, 'Comparison of the fate and toxicity of chlorpyrifos - Laboratory versus a coastal mesocosm system', Ecotoxicology And Environmental Safety, vol. 71, no. 1, pp. 219-229.View/Download from: Publisher's site
The widespread use of chlorpyrifos for pest control in urban and rural environments poses a risk of contamination to aquatic environments via runoff, spray drift or spillage. The aim of this study was to assess the fate of chlorpyrifos and its toxicity t
Patra, R, Chapman, JC, Lim, RP & Gehrke, P 2007, 'The effects of three organic chemicals on the upper thermal tolerances of four freshwater fishes', Environmental Toxicology And Chemistry, vol. 26, no. 7, pp. 1454-1459.View/Download from: Publisher's site
The upper temperature tolerance limits of four freshwater fish species, silver perch Bidyanus bidyanus, eastern rainbowfish Melanotaenia duboulayi, western carp gudgeon Hypseleotris klunzingeri, and rainbow trout Oncorhynchus mykiss, were determined usin
Game, C, Gagnon, M, Webb, D & Lim, RP 2006, 'Endocrine disruption in make mosquitofish (Gambusia holbrooki) inhabiting wetlands in Westerna Australia', Ecotoxicology, vol. 15, no. 8, pp. 665-672.View/Download from: Publisher's site
The use of gonopodial indices as potential indicators of endocrine disruption in the mosquitofish Gambusia holbrooki inhabiting south west Australian wetlands was investigated. A minimum of 50 mature makes was collected from each of five water-bodies in the Swan Coastal Plain, Western Australia, in order to measure morphological features related to reproduction. A set of morphological measurements were used to derive the following indices: gonopodium length/ standard body length, pre-anal length/standard body length, the index of elongation and the percentage of male fish with hooks on the distal end of the gonopodium. Indices of male mosquitofish collected from Jack Finney Lake, located in the Curtin University campus, suggest the presence of endocrine disrupting chemicals (EDCs) in this eater-body, while those from Lake Kulinup suggest this is a site of concern. Indices of male fish from the Wagerup wetland, Lake Monger and Loch McNess indicate that fish inhabiting these wetlands are not affected by EDCs. This preliminary study suggests that EDCs may be present ina number of wetlands of the Swan Coastal Plain. Further study using EDC specific markers such as vitellogenin induction in male mosquitofish is required to confirm whether EDCs are present in these water-bodies.
Phyu, YL, Warne, MSJ & Lim, RP 2006, 'Toxicity and bioavailability of atrazine and molinate to the freshwater fish (Melanotenia fluviatilis) under laboratory and simulated field conditions', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 356, no. 1-3, pp. 86-99.View/Download from: Publisher's site
Rawson, CA, Lim, RP, Warne, MS & Doyle, C 2006, 'The effect of 17 beta-estradiol on the development of modified hemal spines in early-life stage Gambusia holbrooki', Archives Of Environmental Contamination And Toxicology, vol. 51, no. 2, pp. 253-262.View/Download from: Publisher's site
The morphologic development of the gonopodium of male mosquitofish, Gambusia holbrooki, is essential for proper reproductive function and has previously been used as a biomarker for the presence of endocrine-disrupting chemicals (EDCs) in freshwater syst
Rose, RM, Carruthers, A, Stauber, JL, Lim, RP & Blockwell, S 2006, 'Development of an acute toxicity test with the marine copepod acartia sinjiensis', Australasian Journal of Ecotoxicology, vol. 12, pp. 67-75.
Few toxicity test protocols with tropical marine species are currently available in Australasia. In this study, an acute 48h immobilisation toxicity test was developed with an native marine copepod Acartia sinjiensis. This species is widley distributed in tropical and sub-tropical brackish waters in Australia and is an important component of marine food webs. A comparison of its sensitivity to other species shwoed that this copepod was amongst the most sensitive Australian species to copper
Doyle, C & Lim, RP 2005, 'Sexual behavior and impregnation success of adult male mosquitofish following exposure to 17 beta-estradiol', Ecotoxicology And Environmental Safety, vol. 61, no. 3, pp. 392-397.View/Download from: Publisher's site
The effects of 17 beta-estradiol (E-2) on the sexual activity of adult male mosquitofish (Gambusia holbrooki) were assessed. Sexually mature males were exposed to nominal concentrations of 20, 100, and 500 ng/L of E-2 and a solvent control (0.00001% etha
Hogan, AC, Stauber, JL, Pablo, F, Adams, MS & Lim, RP 2005, 'The development of marine Toxicity Identification Evaluation (TIE) procedures using the unicellular alga Nitzschia closterium', Archives Of Environmental Contamination And Toxicology, vol. 48, no. 4, pp. 433-443.View/Download from: Publisher's site
Unicellular algae are highly sensitive to a wide range of toxicants and have been used extensively in ecotoxicological testing. This, along with their ability to grow in very small test volumes over short test durations, make them ideal test organisms fo
Hose, GC, Jones, PM & Lim, RP 2005, 'Hyporheic macroinvertebrates in riffle and pool areas of temporary streams in south eastern Australia', Hydrobiologia, vol. 532, no. 1-3, pp. 81-90.
The hyporheic zone is an important refuge for invertebrates as surface water recedes in temporary streams. In this study, the structure and functional organisation of hyporheic macroinvertebrate assemblages in pool and dry riffle bed habitats of two epis
Phyu, YL, Warne, MS & Lim, RP 2005, 'Effect of river water, sediment and time on the toxicity and bioavailability of molinate to the marine bacterium Vibrio fischeri (Microtox)', Water Research, vol. 39, no. 12, pp. 2738-2746.View/Download from: Publisher's site
The toxicity and bioavailability of molinate to Vibrio fischeri (Microtox (R)) were determined in both laboratory and river water in the absence and presence of sediment after 0, 24, 48, 72 and 96-h exposure. The bioavailability of molinate, expressed as
Phyu, YL, Warne, MS & Lim, RP 2005, 'The toxicity and bioavailability of atrazine and molinate to Chironomus tepperi larvae in laboratory and river water in the presence and absence of sediment', Chemosphere, vol. 58, no. 9, pp. 1231-1239.View/Download from: Publisher's site
Acute (10day) semi-static toxicity tests in which the midge, Chironomus tepperi, were exposed to atrazine and molinate were conducted in laboratory water and in river water, in the absence and presence of sediment. The bioavailability measured as median
Phyu, YL, Warne, MS & Lim, RP 2005, 'Toxicity and bioavailability of atrazine and molinate to the freshwater shrimp (Paratya australiensis) under laboratory and simulated field conditions', Ecotoxicology and Environmental Safety, vol. 60, pp. 113-122.View/Download from: Publisher's site
Acute (96-h) semistatic toxicity tests were conducted by exposing the freshwater shrimp, Paratya australiensis, to atrazine and molinate in laboratory water and in river water both with and without sediment. The median lethal concentrations (LC50) and 95% fiducial limits of atrazine for P. australiensis in laboratory water in the absence and presence of sediment were 9.9 (8.6-11.5) and 6.8 (5.4-8.5)mg/L, respectively, while the corresponding values in river water were 9.8 (8.5-11.2) and 6.5 (5.4-7.8)mg/L, respectively. For molinate, the LC50 values in laboratory water in the absence and presence of sediment were 9.2 (7.0-12.1) and 9.0 (6.8-12.0)mg/L, respectively and the corresponding values in river water were 8.7 (6.4-11.8) and 8.2 (6.6-10.2)mg/L, respectively. Neither the river water nor the presence of sediment significantly (P<0.05) reduced the bioavailability of either chemical to P. australiensis. This was unexpected, as studies with other aquatic organisms have shown that sediment significantly reduced the bioavailability of these chemicals.
Franklin, NM, Stauber, JL & Lim, RP 2004, 'Development of multispecies algal bioassays using flow cytometry', Environmental Toxicology And Chemistry, vol. 23, pp. 1452-1462.View/Download from: Publisher's site
Phyu, YL, Warne, MS & Lim, RP 2004, 'Toxicity of atrazine and molinate to the cladoceran Daphnia carinata and the effect of river water and bottom sediment on their bioavailability', Archives of Environmental Contamination and Toxicology, vol. 46, no. 3, pp. 308-315.View/Download from: Publisher's site
Rose, RM, Warne, MS & Lim, RP 2004, 'Sensitivity of offspring to chronic 3,4-dichloroaniline exposure varies with maternal exposure', Ecotoxicology and Environmental Safety, vol. 58, no. 3, pp. 405-412.View/Download from: Publisher's site
Westbury, A, Warne, MS & Lim, RP 2004, 'Toxicity of, and development of predictive models for, substituted phenols to Ceridaphnia cf. dubia and Vibrio fischeri', Australasian Journal for Ecotoxicology, vol. 10, no. 1, pp. 33-42.
Twelve substituted phenols that have a polar narcotic mode of action had their acute toxicity to the freshwater cladoceran Ceriodaphnia cf. dubia and the marine bacterium Vibrio fischeri determined. The 48-h EC50 (immobilisation) values of the chemicals to C. cf. dubia ranged from 6.13 to 183 Êmol/L while the 30-min EC50 (luminescence) values of the chemicals to V. fischeri ranged from 1.39 to 1031 Êmol/L. Seventy-five percent of the chemicals were classed as having moderate toxicity of to C. cf. dubia while 25 percent had below toxicityf. For V. fischeri the percentage of chemicals classified as having high moderate and below toxicity was approximately 17%, 33% and 50% respectively. Quantitative activity-activity relationships (QAARs) that could predict the toxicity of chemicals with a polar narcotic mode of action to C. cf. dubia were developed by regressing the toxicity data for polar narcotic chemicals to C. cf. dubia with that of eight non-Australasian species. Those QAARs based on the toxicity data for Tetrahymena pyriformis, Chlorella vulgaris, Poecilia reticulata and Daphnia magna were of high quality (r2 . 0.9). Only the QAARs for T. pyriformis, C. vulgaris and D. magna had sufficient data to test their validity. This revealed that the absolute percentage difference between experimentally derived EC50 values and those predicted by these QAARs were between 13 and 120%. These QAARs provide an easy, cost-effective means of estimating toxicity values for polar narcotic chemicals to C. cf. dubia.
Binet, MT, Adams, MA, King, CK, Stauber, JL, Doyle, C, Lim, RP & Laginestra, E 2003, 'Toxicity assessment of leachates from Homebush Bay landfills', Australasian Journal of Ecotoxicology, vol. 9, pp. 7-18.
Doyle, C, Pablo, F, Lim, RP & Hyne, RV 2003, 'Assessment of metal toxicity in sediment pore water from Lake Macquarie, Australia', Archives Of Environmental Contamination And Toxicology, vol. 44, no. 3, pp. 343-350.View/Download from: Publisher's site
Recent investigations into the level of heavy metal enrichment in the sediments of Lake Macquarie have indicated that significant contamination has occurred over the past 100 years, with elevated levels of lead, zinc, cadmium, copper, and selenium being observed in most parts of the lake. Pore water extracted from sediments showing the greatest contamination by these metals exhibited toxicity to the larval development of the sea urchin Heliocidaris tuberculata. However, an analysis of pore water metal concentrations revealed that the concentrations of these metals were too low to cause toxicity. Rather, pore water toxicity was highly correlated with manganese for the majority of sites sampled; subsequent spiking experiments confirmed manganese as a cause of toxicity. Current levels of manganese in the sediments of Lake Macquarie have arisen from natural sources and are not the result of anthropogenic activities. These results reiterate the importance of identifying the causes of toxicity in assessments of sediment contamination, particularly when testing sediment pore waters using sensitive early life stages.
Gale, SA, Smith, SV, Lim, RP, Jeffree, R & Petocz, P 2003, 'Insights into the mechanisms of copper tolerance of a population of black-banded rainbowfish (Melanotaenia nigrans) (Richardson) exposed to mine leachate, using Cu-64/67', Aquatic Toxicology, vol. 62, no. 2, pp. 135-153.View/Download from: Publisher's site
Hammerton, KM, Jayasinghe, N, Jeffree, R & Lim, RP 2003, 'Experimental Study Of Blood Lead Kinetics In Estuarine Crocodiles (Crocodylus Porosus) Exposed To Ingested Lead Shot', Archives Of Environmental Contamination And Toxicology, vol. 45, no. 3, pp. 390-398.View/Download from: Publisher's site
A previous study of lead (Pb) contamination in estuarine crocodiles (Crocodylus porosus) in Kakadu National Park, Australia, found elevated Pb levels in bone and flesh from individuals caught in habitats where hunting with lead ammunition had occurred. L
Hose, GC, Hyne, RV & Lim, RP 2003, 'Toxicity of endosulfan to Atalophlebia spp. (ephemeroptera) in the laboratory, mesocosm, and field', Environmental Toxicology And Chemistry, vol. 22, no. 12, pp. 3062-3068.View/Download from: Publisher's site
Hose, GC, Lim, RP & Hyne, RV 2003, 'The transport, fate and effects of endosulfan in the Australian freshwater environment', Australasian Journal of Ecotoxicology, vol. 9, pp. 101-111.
Hose, GC, Lim, RP, Hyne, RV & Pablo, F 2003, 'Short-term exposure to aqueous endosulfan affects macroinvertebrate assemblages', Ecotoxicology And Environmental Safety, vol. 56, no. 2, pp. 282-294.View/Download from: Publisher's site
The toxicity of the organochlorine pesticide endosulfan to macroinvertebrate assemblages was tested using a system of 24 artificial streams. In separate experiments, the effects of 12- and 48-h exposure to aqueous endosulfan were assessed. No-observed-effect concentrations (NOEC) for endosulfan on macroinvertebrate assemblages were 8.69 and 1.00 µg/L for the 12- and 48-h exposure studies, respectively. In both studies, changes were driven by reduced abundances of the mayfly, Jappa kutera. Algal blooms occurred in the 48-h exposure experiment in streams that received the 6.87 or 30.70 µg/L treatments. These effects occurred at concentrations that might occur as a result of episodic events such as accidental overspray or rainstorms. By establishing a causal link between endosulfan and changes to macroinvertebrate assemblages, this study adds further weight to the hypothesis that endosulfan is a major contributor to changes observed in rivers of the cotton-growing region of New South Wales, Australia during the pesticide spray season.
Markich, SJ, Brown, PL, Jeffree, R & Lim, RP 2003, 'The effects of pH and dissolved organic carbon on the toxicity of cadmium and copper to a freshwater bivalve: Further support for the extended free ion activity model', Archives Of Environmental Contamination And Toxicology, vol. 45, no. 4, pp. 479-491.View/Download from: Publisher's site
Rose, RM, Warne, MS & Lim, RP 2003, 'Exposure to chemicals exuded by fish reduces the filtration and ingestion rates of Ceriodaphnia cf. dubia', Hydrobiologia, vol. 501, no. 1-3, pp. 215-217.View/Download from: Publisher's site
Settacharnwit, S, Buckney, RT & Lim, RP 2003, 'The nutrient status of Nong Han, a shallow tropical lake in north-eastern Thailand: spatial and temporal variations', Lakes & Reservoirs: Research and Management, vol. 8, pp. 189-200.View/Download from: Publisher's site
Colville, AE & Lim, RP 2003, 'Microscopic structure of the mantle and palps in the freshwater mussels Velesunio ambigus and Hyridella depressa (Bivalvia : Hyriidae)', Mulluscan Research, vol. 23, pp. 1-20.View/Download from: Publisher's site
Doyle, C & Lim, RP 2002, 'The effect of 17 beta-estradiol on the gonopodial development and sexual activity of Gambusia holbrooki', Environmental Toxicology and Chemistry, vol. 21, no. N/A, pp. 2719-2724.
Doyle, CJ & Lim, RP 2002, 'The effect of 17β-estradiol on the gonopodial development and sexual activity of Gambusia holbrooki', Environmental Toxicology and Chemistry, vol. 21, no. 12, pp. 2719-2724.View/Download from: Publisher's site
Many chemicals have recently been demonstrated to possess estrogenic activity and may potentially interfere with normal sexual development. In the present study, we quantified the effects of waterborne exposure to 17β-estradiol on the gonopodial development and sexual activity of male eastern mosquitofish (Gambusia holbrooki). Juvenile males were exposed during the period of sexual maturation to nominal concentrations of 20, 100, and 500 ng/L of 17β-estradiol and a solvent control (0.00003% w/v ethanol) for 84 d under continuous-flow conditions. Following exposure, significant differences were found among the test treatments with respect to gonopodial length and degree of gonopodial elongation of the fish. Sexual activity, measured as the number of approaches and copulatory attempts made by the exposed males to nonexposed females, also significantly decreased with increasing concentrations of 17β-estradiol. Because the degree of gonopodial maturation and frequency of sexual activity are important characteristics for the reproductive success of male mosquitofish, it is suggested that these traits provide sensitive and ecologically relevant endpoints for assessing estrogenic activity under both laboratoryand field-exposure conditions.
Franklin, NM, Stauber, JL, Apte, SC & Lim, RP 2002, 'Effect of initial cell density on the bioavailability and toxicity of copper in microalgal bioassays', Environmental Toxicology and Chemistry, vol. 21, no. 4, pp. 742-751.View/Download from: 2.0.CO;2">Publisher's site
Algal toxicity tests based on growth inhibition over 72 h have been extensively used to assess the toxicity of contaminants in natural waters. However, these laboratory tests use high cell densities compared to those found in aquatic systems in order to obtain a measurable algal response. The high cell densities and test duration can result in changes in chemical speciation, bioavailability, and toxicity of contaminants throughout the test. With the recent application of flow cytometry to ecotoxicology, it is now possible to use lower initial cell densities to minimize chemical speciation changes. The speciation and toxicity of copper in static bioassays with the tropical freshwater alga Chlorella sp. and the temperate species Selenastrum capricornutum (Pseudokirchneriella subcapitata) were investigated at a range of initial cell densities (102-105 cells/ml). Copper toxicity decreased with increasing initial cell density. Copper concentrations required to inhibit growth (cell division) rate by 50% (72-h median effective concentration [EC50]) increased from 4.6 to 16 μg/L for Chlorella sp. and from 6.6 to 17 μg/L for S. capricornutum as the initial cell density increased from 102 to 105 cells/ml. Measurements of anodic stripping voltammetry-labile, extracellular, and intracellular copper confirmed that at higher initial cell densities, less copper was bound to the cells, resulting in less copper uptake and lower toxicity. Chemical measurements indicated that reduced copper toxicity was due primarily to depletion of dissolved copper in solution, with solution speciation changes due to algal exudates and pH playing a minor role. These findings suggest that standard static laboratory bioassays using 104 to 105 algal cells/ml may seriously underestimate metal toxicity in natural waters.
Franklin, NM, Stauber, JL, Apte, SC & Lim, RP 2002, 'The effect of initial cell density on the bioavailability and toxicity of copper in microalgal bioassays', Environmental Toxicology and Chemistry, vol. 21, no. N/A, pp. 742-751.
Franklin, NM, Stauber, JL, Lim, RP & Petocz, P 2002, 'Toxicity of metal mixtures to a tropical freshwater alga (Chlorella sp): The effect of interactions between copper, cadmium, and zinc on metal cell binding and uptake', ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, vol. 21, no. 11, pp. 2412-2422.View/Download from: 2.0.CO;2">Publisher's site
Franklin, NM, Stauber, JL, Lim, RP & Petocz, P 2002, 'Toxicity of metal mixtures to a tropical freshwater alga (Chlorella sp.): effect of interactions between copper, cadmium and zinc on metal cell binding and uptake', Environmental Toxicology and Chemistry, vol. 21, no. N/A, pp. 2412-2422.
Franklin, NM, Stauber, JL, Lim, RP & Petocz, P 2002, 'Toxicity of metal mixtures to a tropical freshwater alga (Chlorella sp.): The effect of interactions between copper, cadmium, and zinc on metal cell binding and uptake', Environmental Toxicology and Chemistry, vol. 21, no. 11, pp. 2412-2422.View/Download from: Publisher's site
The individual and combined effects of copper, cadmium, and zinc on the cell division rate of the tropical freshwater alga Chlorella sp. were determined over 48 to 72 h. Metal mixtures were prepared based on multiples of their single-metal median effective concentration (EC50) values, i.e., toxic units (TU) using a triangular mixture design with five toxicant levels (0, 0.75, 1.0, 1.25, and 1.5 TU). Single-metal EC50 values after a 72-h exposure were 0.11, 0.85, and 1.4 μM for copper, cadmium, and zinc, respectively. Significant interactions were observed for all metal combinations after 48 and 72 h. An equitoxic mixture of Cu + Cd was more than concentration additive (synergistic) to the growth of Chlorella sp., while combinations of Cu + Zn, Cd + Zn, and Cu + Cd + Zn were all less than concentration additive or were antagonistic. To determine the effect of each metal on the uptake of the other, extracellular (membrane-bound) and intracellular metal concentrations, both alone and in mixtures, were compared. The increased growth inhibition observed for mixtures of Cu + Cd was due to higher concentrations of cell-bound and intracellular copper in the presence of cadmium compared with copper alone (i.e., cadmium-enhanced copper uptake). In contrast, both extra- and intracellular cadmium concentrations were reduced in the presence of copper. In mixtures of Cu + Zn, copper also inhibited the binding and cellular uptake of zinc, which resulted in decreased toxicity. Zinc had no appreciable effect on the uptake of copper by Chlorella sp. Our results suggest that all three metals share some common uptake and transport sites on Chlorella cells and that copper out competes both cadmium and zinc for cell binding. Determination of metal cell distribution coefficients (Kd) confirmed that Kd values for cadmium and zinc in single-metal exposures decreased in the presence of copper.
Hose, GC, Lim, RP, Hyne, RV & Pablo, F 2002, 'A pulse of endosulfan-contaminated sediment affects macroinvertebrates in artificial streams', Ecotoxicology and Environmental Safety, vol. 51, no. 1, pp. 44-52.View/Download from: Publisher's site
The toxicity of the organochlorine pesticide endosulfan to macroinvertebrate communities was tested using a system of 24 artificial streams. Macroinvertebrate communities in the streams were exposed to a range of endosulfan concentrations for a 12-h period and then monitored for 96 h. Endosulfan was prebound to fine river sediment and applied to the streams as a contaminated sediment slurry. This did not cause changes in the structure of benthic communities; however, significant changes (P<0.05) in the abundance of several macroinvertebrate taxa in drift were detected in the streams receiving the highest (6.14 µg/L) dose. Increased drift may have implications for recolonization processes in lowland rivers, and, as such, pulses of contaminated sediment are likely to result in significant effects on macroinvertebrate populations and communities. This study highlights the utility of artificial stream systems for detecting sublethal effects and the need for population and community-level endpoints to be included in such studies.
Lim, RP, Milner, RJ & Hunter, DM 2002, 'Risks to the aquatic ecosystem from the application of Metarhizium anisopliae for locust control in Australia', Pest Management Science, vol. 58, no. N/A, pp. 718-723.View/Download from: Publisher's site
Rose, RM, Warne, MS & Lim, RP 2002, 'Food concentration affects the life history responses of Ceriodaphnia cf. dubia to chemicals with diffeence mechanisms of action', Ecotoxicology and Environmental Safety, vol. 51, no. N/A, pp. 106-114.View/Download from: Publisher's site
Rose, RM, Warne, MSJ & Lim, RP 2002, 'Residual effects of 3,4-dichloroaniline on offspring born to Ceriodaphnia cf. dubia exposed for multiple generations', Journal of Aquatic Ecosystem Stress and Recovery, vol. 9, no. 3, pp. 205-211.View/Download from: Publisher's site
One of the acknowledged limitations of conventional toxicity tests is their inability to evaluate the impact of toxicants on subsequent generations. Given their relatively short lifespan, cladocerans in the field may be exposed to toxicants for several generations. However, it is unclear what effect such an exposure regime could have on the cladoceran fitness after removal of the toxicant. This paper aimed to determine the offspring fitness of juveniles produced by adult Ceriodaphnia cf. dubia exposed to residual levels of 3,4-dichloroaniline over four generations. Mass cultures of Ceriodaphnia cf. dubia were maintained for several generations in various concentrations of 3,4-dichoroaniline (0, 2.5, 5, 10, 15 and 20 μg/L). The mass cultures were re-established every generation using 4th brood neonates <24 h old. Each generation, 4th brood neonates <24 h old were also transferred individually into toxicant-free water and examined until the production of their 3rd brood. F1 offspring of mothers exposed to 15 and 20 μg/L 3,4-dichloroaniline showed significantly (p < 0.05) reduced reproduction compared to the controls. No significant (p > 0.05) changes in reproduction due to 3,4-dichloroaniline were observed for the F2 and F3 offspring. However, F4 offspring of mothers exposed to all 3,4-dichloroaniline concentrations showed significantly (p < 0.05) increased reproduction compared to the controls. Possible explanations for the varying influence of maternal 3,4-dichloroaniline exposure on the reproductive output of the offspring are discussed.
Rose, RW, Warne, MS & Lim, RP 2002, 'Some Life History Responses Of The Cladoceran Ceriodaphnia Cf. Dubia To Variations In Population Density At Two Different Food Concentrations', Hydrobiologia, vol. 481, no. 1-3, pp. 157-164.View/Download from: Publisher's site
The combined effects of food concentration and population density on some life history characteristics of the small-bodied cladoceran Ceriodaphnia cf. dubia were studied by examining animals maintained at densities of 100-3000 individuals l(-1) for 8 day
Franklin, NM, Adams, MS, Stauber, JL & Lim, RP 2001, 'Development of an Improved Enzyme Inhibition Bioassay with Marine and Freshwater Algae Using Flow Cytometry', Archives of Environmental Contamination and toxicology, vol. 40, pp. 469-480.
Franklin, NM, Stauber, JL & Lim, RP 2001, 'Development of a Flow Cytometry-Based Algal Bioassays for Assessing Toxicity of Copper in Natural Waters', Environmental Toxicology and Chemistry, vol. 20, no. 1, pp. 160-170.View/Download from: Publisher's site
Leonard, AW, Hyne, RV, Lim, RP, Leigh, KA, Le, J & Beckett, R 2001, 'Fate and Toxicity of Endosulfan in Namoi River Water and Bottom Sediment', Journal of Environmental Quality, vol. 30, no. 3, pp. 750-759.View/Download from: Publisher's site
Lim, R, Gale, S, Doyle, C, Lesjean, B & Gilbert, M 2001, 'Endocrine disrupting compounds in effluent reused in agriculture', Water, vol. 28, no. 3, pp. 26-30.
A brief review is given on the presence, fate and impact of EDCs in sewage effluent reused in agriculture on crop plants and livestock. Mammalian hormones and to a lesser extent some synthetic chemicals and metals may potentially pose some risk to plants and animals. However, there is a paucity of studies and therefore the precautionary principle should underpin the reuse of sewage effluent in agriculture, and the effectiveness of STP treatments on removal of EDCs in reclaimed waters warrants greater attention.
Rose, RM, Warne, MS & Lim, RP 2001, 'Factors associated with Fish Modify Life History Traits of the Cladoceran Ceriodaphnia cf. dubia', Journal of Plankton Research, vol. 23, no. 1, pp. 11-17.View/Download from: Publisher's site
Rose, RM, Warne, MS & Lim, RP 2001, 'The Presence of Chemicals Exuded by Fish Affects the Life History Response of Ceriodaphnia cf. dubia to Chemicals with Different Mechanisms of Action', Environmental Toxicology and Chemistry, vol. 20, no. 12, pp. 2892-2898.View/Download from: 2.0.CO;2">Publisher's site
Franklin, NM, Stauber, JL, Markich, SJ & Lim, RP 2000, 'pH-Dependent Toxicity of Copper and Uranium to a Tropical Freshwater Alga (Chlorella sp.)', Aquatic Toxicology, vol. 48, no. 0, pp. 275-289.
Franklin, NM, Stauber, JL, Markich, SJ & Lim, RP 2000, 'pH-dependent toxicity of copper and uranium to a tropical freshwater alga (Chlorella sp.)', Aquatic Toxicology, vol. 48, no. 2-3, pp. 275-289.View/Download from: Publisher's site
Copper (Cu) and uranium (U) are of potential ecotoxicological concern to tropical freshwater organisms in northern Australia as a result of mining activity. No local data on the toxicity of these metals to tropical freshwater algae are currently available. The aim of this study was to investigate the effect of pH (5.7 and 6.5) on the toxicity of Cu and U to the green alga Chlorella sp. in a synthetic softwater representative of fresh surface waters in sandy-streams of tropical northern Australia. The effects of Cu and U on algal growth (cell division) rate after a 72-h exposure were determined. Intracellular and extracellular (membrane-bound) metal concentrations at the two selected pH values were also compared. Based on the 72-h minimum detectable effect concentrations (MDEC), Chlorella sp. was approximately 20-fold more sensitive to Cu (0.7 and 1.4 μg l-1 at pH 6.5 and 5.7, respectively) than U (13 and 34 μg l-1 at pH 6.5 and 5.7, respectively), and more sensitive than other Australian tropical freshwater organisms. The toxicity of Cu and U was highly pH-dependent. Copper concentrations required to inhibit growth (cell division) rate by 50% (72-h EC50) increased from 1.5 to 35 μg l-1 as the pH decreased from 6.5 to 5.7. Similarly, the 72-h EC50 values for U increased from 44 to 78 μg l-1 over the same pH range. Calculation of Cu and U speciation using the geochemical model HARPHRQ, showed that differences in the concentrations of the free metal ions (Cu2+ and UO2/2+) were only minimal (<10%) between pH 5.7 and 6.5. The decreased toxicity at pH 5.7 was due to lower concentrations of cell-bound and intracellular Cu and U compared to those at pH 6.5. These results are explained in terms of the possible mechanism of competition between H+ and the metal ion at the cell surface. (C) 2000 Elsevier Science B.V.
Leonard, AW, Hyne, RV, Lim, RP, Pablo, F & Van den Brink, P 2000, 'Riverine Endosulfan Concentrations in the Namoi River, Australia: Link to Cotton Field Runoff and Macroinvertebrate population Densities', Environmental Toxicology and Chemistry, vol. 19, no. 6, pp. 1540-1551.View/Download from: 2.3.CO;2">Publisher's site
Markich, SJ, Brown, PL, Jeffree, RA & Lim, RP 2000, 'Valve movement responses of Velesunio angasi (Bivalvia: Hyriidae) to manganese and uranium: An exception to the free ion activity model', Aquatic Toxicology, vol. 51, no. 2, pp. 155-175.View/Download from: Publisher's site
The veracity of the free ion activity model (FIAM) was tested by examining the acute (48 h) valve movement responses (VMR) (measured in terms of the duration of valve opening) of the Australian tropical freshwater unionid bivalve, Velesunio angasi to increasing concentrations of total Mn or U, in a standard synthetic water under conditions of varying pH (5.0-6.0) and/or dissolved organic carbon (model fulvic acid, FA) concentrations (0-8.9 mg l-1). Valve movement behaviour, measured using an automated data acquisition system, was shown to be a quantifiable and rapid, real-time endpoint for assessing the toxic effects of Mn and U exposures. For Mn, the VMR of V. angasi were independent (P > 0.05) of pH and/or model FA concentration. In contrast, VMR to U exposures were highly dependent (P ≤ 0.05) on pH and/or model FA concentration; individuals were more sensitive to U at low pH and model FA concentrations. Valve movement responses to Mn were directly proportional to the activity of the free metal ion (Mn2+), which is consistent with the FIAM. In contrast, VMR to U were regarded as an 'exception' to the FIAM, since they were a weighted function of the activities of the free metal ion and the 1:1 metal hydroxide species (i.e. 1.86 x UO22+ + UO2OH+). Additionally, the effect of U on V. angasi demonstrates the importance of examining VMR at more than one pH. At a fixed pH, the results for U were consistent with the FIAM (i.e. response was directly proportional to UO22+); only when pH was altered, were the results inconsistent with the FIAM. The inconsistency in the VMR of V. angasi to U exposures in this study, together with similar examples from other studies using different metals (e.g. Al or Zn), raises questions regarding the veracity of the FIAM. A detailed examination of the conceptual development of the FIAM is required to probe its apparent failure to describe several metal-organism interactions. (C) 2000 Elsevier Science B.V.
Markich, SJ, Brown, PR, Jeffree, R & Lim, RP 2000, 'Valve Movement Responses of Velesunio angasi (Bivalvia: Hyriidae) to Manganese and Uranium: An Exception to the Free Ion Activity Model', Aquatic Toxicology, vol. 51, no. 0, pp. 155-175.
Roach, AC & Lim, RP 2000, 'Variation in the population dynamics of the intertidal pulmonate gastropod Salinator solida Martens (Gastropoda: Amphibolidae) at Towra Point, NSW, Australia', Wetlands Ecology and Management, vol. 8, no. 1, pp. 53-69.View/Download from: Publisher's site
This paper describes variation in the population dynamics of the intertidal pulmonate gastropod Salinator solida among mangrove and saltmarsh habitats at Towra Point, NSW, Australia over a two-year period. In general, this paper describes the degree to which the density of the populations fluctuated and the size structure of the populations varied among heights on shore. The density of individuals in the upper mangrove forest was most variable through time and their population size structure was dominated by smaller individuals. The density of populations in the Sarcocornia high on the shore fluctuated least through time and were dominated by large individuals. Those populations found on the mid-shore in the Sarcocornia had population characteristics intermediate to those populations in the upper mangrove forest and the Sarcocornia high on the shore. Analysis of size frequency data indicated that the growth rates of individuals and their annual mortality decreased with increasing height on shore.
Rose, RM, Warne, MS & Lim, RP 2000, 'Life history responses of the cladoceran Ceriodaphnia cf. dubia to variation in food concentration', HYDROBIOLOGIA, vol. 427, no. 1-3, pp. 59-64.View/Download from: Publisher's site
Rose, RW, Warne, MS & Lim, RP 2000, 'Life History Response of the the Cladeceran Ceriodaphnia cf. dubia to Variation in Food Concentration', Hydrobiologia, vol. 427, no. 0, pp. 59-64.
Batty, J & Lim, R 1999, 'Morphological and reproductive characteristics of male mosquitofish (Gambusia affinis holbrooki) inhabiting sewage-contaminated waters in New South Wales, Australia', Archives of Environmental Contamination and Toxicology, vol. 36, no. 3, pp. 301-307.View/Download from: Publisher's site
The potential effects of exposure of fish to reproductive endocrine disruptors (REDs) is of major concern. This study reports on the effects of sewage effluent exposure on morphology of male mosquitofish (Gambusia a. holbrooki) in a tributary of the Hawksbury-Nepean River system in New South Wales, Australia. The growth and development of the modified anal fin (the gonopodium, GP) is a secondary sexual characteristic in males, forms under the influence of testosterone, and is critical for sperm transfer. The GP was reduced in length in males sampled downstream from a sewage treatment plant discharge point compared to GP fin length in males upstream or from other comparison sites. The reduction in size of this androgen-dependent structure suggests the presence of RED substances in the water. The presence or absence of spermatozeugmata (sperm packet) was not related to a reduction in GP length, which suggests spermatogenesis may not be reduced, but other measures of fertility remain to be evaluated. These results are discussed in the context of RED contaminants associated with sewage effluent.
Leonard, AW, Hyne, RV, Lim, RP & Chapman, JC 1999, 'Effect Of Endosulfan Runoff From Cotton Fields On Macroinvertebrates In The Namoi River', Ecotoxicology And Environmental Safety, vol. 42, no. 2, pp. 125-134.View/Download from: Publisher's site
Of the several pesticides used in the pest management strategy for cotton, endosulfan is ranked as having the greatest impact on the riverine ecosystem. A survey of changes in the densities of six abundant macroinvertebrate taxa (ephemeropteran nymphs Ja
Rose, RW, Warne, MS & Lim, RP 1998, 'Quantitative Structure-Activity Relationships And Volume Fraction Analysis For Nonpolar Narcotic Chemicals To The Australian Cladoceran Ceriodaphnia Cf. Dubia', Archives Of Environmental Contamination And Toxicology, vol. 34, no. 3, pp. 248-252.View/Download from: Publisher's site
The toxicity of eleven nonpolar narcotic chemicals to the cladoceran Ceriodaphnia cf. dubia was determined. C. cf. dubia was found to be approximately four times more sensitive to these narcotic chemicals than Daphnia magna tested under virtually identic
Howe, E, Howe, C, Lim, R & Burchett, M 1997, 'Impact of the introduced poeciliid Gambusia holbrooki (Girard, 1859) on the growth and reproduction of Pseudomugil signifer (Kner, 1865) in Australia', Marine and Freshwater Research, vol. 48, no. 5, pp. 425-434.View/Download from: Publisher's site
The impact of the presence of the introduced poeciliid Gambusia holbrooki on the Australian pseudomugilid Pseudomugil signifer was examined in open-air tank experiments. G. holbrooki profoundly affected the breeding of R signifer. In the presence of G. holbrooki, P. signifer did not gain weight or grow in total length, ovarian weight and fecundity were greatly reduced, and the ovaries were morphologically undeveloped. No eggs of P. signifer were observed in tanks that also housed G. holbrooki. The results indicate that, at least in a captive situation, the presence of the exotic species bad a very deleterious effect on the breeding and hence possible survival of the native species. These results are discussed with reference to the conservation of Australian pseudomugilid species, especially those inhabiting confined habitats.
Olima, C, Pablo, F & Lim, RP 1997, 'Comparative Tolerance Of Three Populations Of The Freshwater Shrimp (Paratya Australiensis) To The Organophosphate Pesticide, Chlorpyrifos', Bulletin Of Environmental Contamination And Toxicology, vol. 59, no. 2, pp. 321-328.View/Download from: Publisher's site
Pablo, F, Buckney, RT & Lim, RP 1997, 'Toxicity Of Cyanide, Iron-Cyanide Complexes, And A Blast Furnace Effluent To Larvae Of The Doughboy Scallop, Chlamys Asperrimus', Bulletin Of Environmental Contamination And Toxicology, vol. 58, no. 1, pp. 93-100.View/Download from: Publisher's site
Pablo, F, Buckney, RT & Lim, RP 1997, 'Toxicity Of Cyanide, Iron-Cyanide Complexes, And A Blast-Furnace Effluent To The Banana Prawn, Penaeus Monodon', Bulletin Of Environmental Contamination And Toxicology, vol. 58, no. 5, pp. 822-829.View/Download from: Publisher's site
Abdullah, AR, Lim, RP & Chapman, JC 1993, 'Inhibition and recovery of acetylcholinesterase in Paratya australiensis exposed to the organophosphate insecticide chlorpyrifos', Fresenius Environmental Bulletin, vol. 2, no. 12, pp. 752-757.
Khan, I & Lim, RP 1991, 'Distribution Of Metals In The Linggi River Basin, Malaysia, With Reference To Pollution', Australian Journal Of Marine And Freshwater Research, vol. 42, no. 4, pp. 435-449.
Pollution inputs into the Linggi River Basin comprise domestic sewage, agroindustrial effluent (especially from rubber factories and plam-oil mills), and effluent from animal-husbandry activities. Total metals were analysed at eight sampling stations lo
Nather Khan, ISA & Lim, RP 1991, 'Distribution of metals in the linggi river basin, malaysia, with reference to pollution', Marine and Freshwater Research, vol. 42, no. 4, pp. 439-445.View/Download from: Publisher's site
Pollution inputs into the Linggi River Basin comprise domestic sewage, agroindustrial effluent (especially from rubber factories and palm-oil mills), and effluent from animal-husbandry activities. Total metals were analysed at eight sampling stations located at three highly polluted sub-basins:Linggi, Simin and Kundor. Dissolved metals were analysed occasionally at 21 major tributaries. The following concentrations were found (mg L-1; d.l., detection limit):Na, 0• 93—117■ 73; K, 0-88-77-03; Ca, 1-89-24-00; Mg, 0-30-14-78; Fe, 0-47-12-2; Zn, 0-06-5-12; Cu,
Lim, RP & Wong, M 1986, 'The Effect Of Pesticides On The Population-Dynamics And Production Of Stenocypris-Major Baird (Ostracoda) In Ricefields', Archiv Fur Hydrobiologie, vol. 106, no. 3, pp. 421-427.
Lim, RP & Fernando, C 1985, 'A Review Of Malaysian Fresh-Water Copepoda With Notes On New Records And Little Known Species', Hydrobiologia, vol. 128, no. 1, pp. 70-89.
Rahman, MA, Hassler, CS, Hasegawa, H & Lim, RP 2013, 'Ecotoxicology of Arsenic in The Freshwater Environment: Consequences and Risk Assessment' in Andrea Masotti (ed), Arsenic: Sources, Environmental Impact, Toxicity and Human Health - A Medical Geology Perspective, Nova Science Publishers, New York, USA, pp. 85-106.
Arsenic is a known environmental toxicant and it occurs in the environment from natural and anthropogenic sources. Arsenic is one of the important environmental issues because of its occurrence, bioaccumulation, toxicity, and trophic transfer in the freshwater food chain. Aquatic organisms accumulate, retain, and transform arsenic when exposed to it through water, their diet, and other routes. Since arsenic toxicity mostly depends on its chemical forms, measurement of arsenic speciation in aquatic organisms is particularly important in assessing the ecological risks of the element. Arsenate (As(V)) comprises the major part of total arsenic in oxic waters. Phytoplankton take up As(V) and subsequently convert it to arsenite (As(III)) and then to less toxic dimethylarsinic acid (DMAA), monomethylarsonic acid (MMAA), and higher order organoarsenicals. Phytoplankton are thought to convert inorganic arsenic species to methylarsenicals and to other organoarsenic compounds (lipids and arsenosugars) to reduce the toxic effects of inorganic arsenicals. Since phytoplankton are a major food source for the organisms of higher trophic levels in the aquatic systems, arsenic is biotransferred from lower to higher trophic levels; while biomagnification of the element in aquatic food chain is not consistent. Other important arsenic forms found in aquatic organisms include arsenocholine (AsC), arsenobetaine (AsB) and arsenosugars (AsS). This review discusses the bioaccumulation, biotransformation, and trophic transfer (biomagnification or diminution) of arsenic in the aquatic food chains in relation to its ecotoxicological risks in the freshwater environment.
Rahman, MA, Lim, RP & Hasegawa, H 2012, 'Biodegradable chelating ligands for iron and arsenic bioavailability and uptake in rice (Oryza sativa L.)' in Ng, JC, Noller, BN, Naidu, R, Bundschuh, J & Bhattacharya, P (eds), Understanding the Geological and Medical Interface of Arsenic, CRC Press, AK Leiden, The Netherlands, pp. 394-396.
Biodegradable chelating ligands Ethylenediaminedisuccinic acid (EDDS), Hydroxyiminodisuccinic acid (HIDS) and Methylglycindiacetic Acid (MGDA) for iron (Fe) and arsenic (As) bioavailability and uptake were investigated using hydroponic rice (Oryza sativa L.). The growth of rice seedlings decreased significantly (P < 0.05) with increasing pH. The highest growth was observed at pH 7 which was related to Fe concentrations in roots and shoots. As and Fe uptake in rice roots was increased by significantly (P < 0.05) by EDDS and HIDS, while their translocation to shoots were not influenced by the ligands. EDDS and HIDS were more efficient in As and Fe uptake than MGDA indicating that EDDS and HIDS would be good ligands for the increase of Fe uptake and Fe phytoextraction
Polgar, G & Lim, R 2011, 'Mudskippers: Human use, ecotoxicology and biomonitoring of mangrove and other soft bottom intertidal ecosystems' in Mangroves: Ecology, Biology and Taxonomy, Nova, USA, pp. 51-86.
Mudskippers (Gobiidae: Oxudercinae) are air-breathing gobies, which are widely distributed throughout the West African coast and the Indo-Pacific region. They are closely linked to mangrove and adjacent soft bottom peri-tidal ecosystems. Some species are amongst the best adapted fishes to an amphibious lifestyle. All mudskippers are benthic burrowers in anoxic sediments, and since tidal mudflats are efficient sediment traps, and sinks for nutrients and other chemical compounds, they are constantly in contact with several types of pollutants produced by industrial, agricultural and domestic activities. Due to their natural abundance, considerable resistance to highly polluted conditions, and their benthic habits, mudskippers are frequently used in aquatic ecotoxicological studies. For the same reasons, mudskippers also frequently occur in urbanised or semi-natural coastal areas. Since several species are widely consumed throughout their whole geographical range, these same characteristics also facilitate their aquaculture in several countries, such as Bangladesh, Thailand, Philippines, China, Taiwan and Japan. Even when not directly used, mudskippers are often abundant and are important prey items for many intertidal transient species (marine visitors), and several species of shorebirds. Therefore, there is potential for bioaccumulation of toxicants wherever mudskippers and pollution co-occur. This chapter reviews the ecotoxicology of mudskippers, and their potential for use as biomonitors to better manage coastal swamp ecosystems. The diverse sympatric assemblages of mudskipper species allow for spatially differentiated ecotoxicological investigations along the whole intertidal zone, since adults are often territorial and/or sedentary, and show species-specific patterns of habitat differentiation. A case study is also proposed where this approach could be adopted to address potential health-risk issues in a local population who are regular consumers of mudskipper...
Lim, RP & Lai, H 2004, 'Crustacea: Copepoda, Calanoida' in Yule, CM & Sen, YH (eds), Freshwater Invertebrates of the Malaysian Region, Academy of Sciences Malaysia, Kuala Lumpur, Malaysia, pp. 254-266.
Gothe, J, Leung, T, Lim, RP, Phyu, YL, Plant, R & Walker, JR 2011, 'Advocating for Biodiversity in the Hawkesbury Nepean River: critical research practices of visual communication design', Geography on the Edge, Institute of Australian Geographers, University of Wollongong, pp. 1-47.
Plant, R, Walker, JR, Rayburg, SC, Gothe, J, Leung, TM, Phyu, YL & Lim, RP 2011, 'The 'Social Life of Pesticides': How organised irresponsibility in the Greater Sydney Basin threatens the biodiversity of the Hawkesbury-Nepean River', Institute of Australian Geographers (IAG) Conference Wollongong 2011, Wollongong, NSW.
Brennan, EL, Lim, RP, Doyle, C & Laginestra, E 2003, 'The use of Poecilliids to assess the endocrine disrupting capacity of waters with reference to the mosquitofish inhabiting water bodies in the Sydney Olympic Park, Homebush Bay.', Proceedings of Chemicals of Concern in Water Speciality Conference 2003, Chemicals of Concern, Australian Water Association & International Water Association, Sydney, Australia, pp. 1-8.
Doyle, C, Barker, J, Lim, RP & Gray, LE 2003, 'Reproductive morphology of male mosquitofish (gambusia holbrooki) inhabiting sewage-contaminated waters in the South Creek catchment on the Hawkesbury-Nepean River', Proceedings of Chemicals of Concern in Water Speciality Conference 2003, Chemicals of Concern in Water, Australian Water Assocaition & International Water Association, Sydney, Australia, pp. 1-10.
Lim, RP, Gale, SA, Doyle, C, Lesjean, B & Gibert, M 2000, 'Endocrine Disrupting Compounds in Sewage Treatment Plants (STP) Effluent Reused in Agriculture - Is there a Concern?', Water Recycling Australia, CSIRO Land and Water, Adelaide, Australia, pp. 23-28.