ORCID Profile
0000-0001-9424-4599
Current Organisation
University of Melbourne
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Publisher: Elsevier BV
Date: 03-2013
DOI: 10.1016/J.WATRES.2012.12.020
Abstract: Estuaries are often the final repositories for aquatic pollutants but how estuarine hydrology influences the availability of marine- and freshwater-derived pollutants is not well understood, particularly for micro-pollutants such as endocrine disrupting chemicals. To address this knowledge gap, this study measured natural and synthetic estrogen concentrations within the Little River, a tidal estuary in close vicinity to the major discharge point of Melbourne's largest waste water treatment plant (WWTP), the Western Treatment Plant. Quantitative enzyme-linked immunosorbent assays (ELISA) were used to determine concentrations of natural estrogens (ES: ∑E1 (estrone), E2 (17β-estradiol), E3 (estriol)) and the synthetic estrogen, 17α-ethinylestradiol (EE2). The highest concentrations were measured in s les taken from the WWTP effluent discharge channel (29.0 ng/L and 0.35 ng/L, respectively). Within the estuary, concentrations of ES (2.25-23.16 ng/L) varied somewhat between locations and s ling periods (p < 0.05), however patterns were not consistent. Significant spatial variation was observed on only one s ling occasion, and likewise temporal variation was only observed once. In the upstream freshwaters, ES (2.95-7.26 ng/L) concentrations were lower than in the estuary, although their presence suggests an additional source of ES to the environment, most likely of agricultural origin. The EE2 concentrations measured in both the estuarine and freshwater areas were all low (mostly below 0.20 ng/L), which created difficulties in interpretation due to problems associated with trying to measure such low concentrations with confidence. However, some patterns did emerge, with EE2 concentrations exhibiting significant temporal and tidal variation (p < 0.05), with concentrations greatest during low and flooding (incoming) tides. Physico-chemical properties explained 30% of the variation in ES concentrations, whereby concentrations increased with decreasing pH and DO and increasing salinity. Given the higher concentrations observed during flooding tides and the association of higher estrogen concentrations with increased salinity and low DO, we suggest that estrogens might accumulate in estuarine bottom waters and upon disturbance from the incoming tidal flows, may be a contributing source of estrogens into the estuary. This study contributes the first comprehensive investigation of estrogen dynamics in an Australian estuary, and provides the foundation for further research aimed at identifying which compounds are present in estuarine waterways, where they are coming from and how their concentrations vary through space and time.
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.YHBEH.2015.03.002
Abstract: Chemical pollution is a pervasive and insidious agent of environmental change. One class of chemical pollutant threatening ecosystems globally is the endocrine disrupting chemicals (EDCs). The capacity of EDCs to disrupt development and reproduction is well established, but their effects on behaviour have received far less attention. Here, we investigate the impact of a widespread androgenic EDC on reproductive behaviour in the guppy, Poecilia reticulata. We found that short-term exposure of male guppies to an environmentally relevant concentration of 17β-trenbolone-a common environmental pollutant associated with livestock production-influenced the amount of male courtship and forced copulatory behaviour (sneaking) performed toward females, as well as the receptivity of females toward exposed males. Exposure to 17β-trenbolone was also associated with greater male mass. However, no effect of female exposure to 17β-trenbolone was detected on female reproductive behaviour, indicating sex-specific vulnerability at this dosage. Our study is the first to show altered male reproductive behaviour following exposure to an environmentally realistic concentration of 17β-trenbolone, demonstrating the possibility of widespread disruption of mating systems of aquatic organisms by common agricultural contaminants.
Publisher: Springer Science and Business Media LLC
Date: 14-06-2015
DOI: 10.1007/S00128-015-1577-6
Abstract: This pilot study was initiated to provide new information on the 'hormonal' activity of Victorian rivers. Chemcatcher™ passive s ler systems containing Empore™ C18FF disks were deployed at eight riverine sites near Melbourne. Little estrogenic activity [<0.4-1.8 ng estradiol equivalents (EQ)/disk] and no retinoic acid activity (RAR, all s les <0.8 ng trans-retinoic acid EQ/disk) was observed. Almost all s le extracts showed aryl hydrocarbon receptor activity (from <4 to 29 ng β-naphthoflavone EQ/disk). Overall, the disk extracts were eminently compatible with the bioassay screening technology, enabling the relative levels of 'hormonal activity' to be observed in the surface waters in and around Melbourne. From a practical perspective, the in situ s ling and pre-concentration provided by passive s ling reduces the manual handling risks associated with s le transport, and the number of laboratory operations required to obtain assay-ready solutions for analysis.
Publisher: IWA Publishing
Date: 08-2012
DOI: 10.2166/WST.2012.242
Abstract: In 2007, s les of treated effluent were collected at point of discharge to the environment from 39 wastewater treatment plants (WWTPs) located across Victoria, Australia grouped by treatment type. S le genotoxicity was assessed with a high-throughput luminescent umu test method using Salmonella typhimurium TL210 strain, with and without addition of a commercially available metabolic activation system. S les were also screened using a gas chromatographic—mass spectrometric mass-structure database recognition method. A genotoxic response was observed in half of the s les tested without metabolic activation system (& LOR – 0.19 μg/L 4-nitroquinoline-N-oxide equivalents). On addition of metabolic activation system, 75% of s les elicited a genotoxic response, the majority of responses were stronger than without metabolic activation (& LOR – 2.97 μg/L benzo[a]pyrene equivalents). The type of WWTP had no effect on genotoxicity. A large number of chemicals were identified in the effluents, although none could be unambiguously tied to the genotoxicity observed. Chemicals observed in one or more effluents included food additives (e.g. dibenzylether), various alkyl phenols, tyre leachates (e.g. 2(3H)-benzothiazolone), antioxidants, flame retardants (e.g. tris(2-chloroethyl)phosphate), insect repellents (e.g. diethyltoluamide), stimulants (e.g. caffeine) and anticonvulsants (e.g. carbamazepine). Of the 451 pesticides screened, carbamate insecticides (e.g. bendiocarb, propoxur), plant growth regulators (e.g. propham) and herbicides (e.g. atrazine, metolachlor, simazine) were amongst the compounds observed.
Publisher: WIT Press
Date: 30-04-2008
DOI: 10.2495/ETOX080311
Publisher: Springer Science and Business Media LLC
Date: 04-02-2010
DOI: 10.1007/S00244-010-9472-Y
Abstract: The project was conducted between May 2006 and September 2007, and involved the collection of effluent s les from 45 wastewater treatment plants (WWTPs). The 45 WWTPs included 16 lagoon-based plants and 29 with activated sludge-based processes. Permission was obtained from all the relevant water authorities to collect s les of final effluent at point of discharge to the environment, whether that was to a creek, a river, the ocean, or the land. S les were collected on two occasions, namely, in August 2006 (winter) and late February-early March 2007 (summer), and subjected to a number of biological and chemical analyses, including toxicity tests, measurement of hormonal (estrogenic) activity using yeast-based bioassays, and measurement of specific hormonal concentrations using enzyme-linked immunosorbent assays (ELISAs). Almost all of the effluents examined showed estrogenic activity: in winter, no activity to 73 ng/l 17beta-estradiol equivalents (EEQ) and in summer, no activity to 20 ng/l EEQ. On the whole, the levels of estrogenic activity observed were comparable with the range recently reported in Australia and New Zealand using human estrogen receptor-based assays ("not detected" to approximately 10 ng/l EEQ). The low/no bioassay response was confirmed by the chemical assessment of estradiol, estrone, and ethinyl estradiol concentrations by ELISA, which returned concentrations of these compounds for the most part below 10 ng/l.
Publisher: Springer Science and Business Media LLC
Date: 07-2015
Publisher: Springer Science and Business Media LLC
Date: 17-06-2014
DOI: 10.1007/S00244-014-0049-Z
Abstract: Herbicides are regularly applied in horticultural production systems and may migrate off-site, potentially posing an ecological risk to surface waterways. However, few studies have investigated the levels and potential ecotoxicological impact of herbicides in horticultural catchments in southern Australia. This study investigated the presence of 10 herbicides at 18 sites during a 5-month period in horticulturally important areas of the Yarra Valley in southeastern Australia. Seven of the 10 herbicides were detected in the streams, in 39 % of spot water s les, in 25 % of surface sediment s les, and in >70 % of the passive s ler systems deployed. Few s les contained residues of ≥2 herbicides. Simazine was the herbicide most frequently detected in water, sediment, and passive s ler s les and had the highest concentrations in water (0.67 μg/L) and sediment (260 μg/kg dry weight). Generally the concentrations of the herbicides detected were several orders of magnitude lower than reported ecotoxicological effect values, including those for aquatic plants and algae, suggesting that concentrations of in idual chemicals in the catchment were unlikely to pose an ecological risk. However, little is known about the combined effects of simultaneous, low-level exposure of multiple herbicides of the same mode of action on Australian aquatic organisms nor their contribution when found in mixtures with other pesticides. Further research is required to adequately assess the risk of pesticides in Victorian aquatic environments.
Publisher: Springer Science and Business Media LLC
Date: 05-12-2008
DOI: 10.1007/S00244-008-9261-Z
Abstract: There is very little information on the overall level of estrogenic activity, or concentrations of specific hormonal compounds in wastewater treatment plant (WWTP) discharges in Australia, compared with Europe, Japan, and North America. To partly address this, in 2004, water s les were collected as "grab" or "spot" s les from 12 WWTP facilities across southern Victoria at the point at which effluent enters the environment, either as recycled water or direct discharge to the receiving water. The WWTPs were of a variety of treatment types and served a erse range of rural and regional municipalities. For instance, of the 12 WWTPs, 3 served municipalities with populations greater than 100,000, 4 with populations between 20,000 and 100,000, and 5 with populations less than 5,000. The principal treatment process in six was an activated sludge system, and three were trickle-filter-based systems. The remaining plants fall into a "miscellaneous" category, each plant having a mixture of treatment processes within the overall systems. The estrogenic activity and 17beta-estradiol concentrations of the s les were assessed using a yeast-based, in vitro reporter gene assay and enzyme-linked immunosorbant assays, respectively. Most of the effluents showed estrogenic activity in the assays (hER, no response: 7.9 ng/L EEQ mER, no response: 44.5 ng/L EEQ). There was no correlation between estrogenic response and the results of a concurrent toxicity assay, suggesting that a lack of bioassay response was related to lack of estrogenic compounds, rather than the direct toxic effect of the s le. Estradiol concentrations were for the most part in the range 2-5 ng/L, with one s le at 18 ng/L. Despite the assurance our results might provide (of minimal impact in most cases if there is significant dilution), there is still a need for further extensive on-ground reassurance research to provide data for higher-level risk assessment by industry and government agencies. In particular, more research is warranted to verify the estrogenic activity and to expand the range of specific hormone/metabolites reported in these studies. Moreover, studies are required to determine if the estrogenic activity reported in this and other recent Australian studies is sufficient to induce a physiological effect in exposed aquatic organisms, especially Australian native fish.
Publisher: Springer Science and Business Media LLC
Date: 05-2005
Publisher: Springer Science and Business Media LLC
Date: 03-04-2011
DOI: 10.1007/S00244-011-9665-Z
Abstract: This project involved the collection of final effluent s les from 39 wastewater-treatment plants (WWTPs) in Victoria, Australia, in late summer (late February to early March 2007). The 39 WWTPs included 15 lagoon-based plants and 24 with activated sludge-based processes. S les were collected and subjected to measurement of retinoic acid receptor (RAR) and aryl hydrocarbon receptor (AhR) activity of the dissolved phase using yeast-based recombinant receptor-reporter gene bioassays. More than 90% of the effluents examined in this study elicited RAR activity (<0.5-198 ng/l a-t-RA equivalents [EQ]). All of the effluents had AhR activity (16-279 ng/l βNF EQ). Notwithstanding the paucity of comparative data, on the whole, the levels of RAR and AhR activity observed in this pilot survey of Victorian WWTP effluents were greater than those recently reported internationally. One assumption commonly made is that WWTP discharges will be diluted significantly in the receiving environment, further decreasing the potential risk of the discharges. Making this assumption may not be appropriate for some of Victoria's more ephemeral waterways or where effluent is discharged to an enclosed water body, such as a lake or terminal wetland. However, even where WWTP discharges represent all of the environmental flow in the warmer months, the observed RAR and AhR activity (as all-trans-retinoic acid (RA) and 2,3,7,8-tetrachloro-dibenzo-p-dioxin [TCDD] EQ, respectively) was still significantly lower than the concentrations of RA, and 2,3,7,8-TCCD known to cause developmental malformations in fish larvae after short-term exposure to these chemicals. Of perhaps greater concern, WWTP effluent can contain significant suspended solids (essentially biosolids), which may be a considerable sink for some hormonally active, hydrophobic compounds, and which may in turn increase the long-term exposure risk for aquatic fauna. Further studies of the nuclear and AhR activity of WWTP effluent suspended soilds are required to address this hypothesis.
Publisher: Springer Science and Business Media LLC
Date: 21-02-2015
DOI: 10.1007/S11356-015-4206-3
Abstract: S les of water and sediments were collected from 24 urban wetlands in Melbourne, Australia, in April 2010, and tested for more than 90 pesticides using a range of gas chromatographic (GC) and liquid chromatographic (LC) techniques, s le 'hormonal' activity using yeast-based recombinant receptor-reporter gene bioassays, and trace metals using spectroscopic techniques. At the time of s ling, there was almost no estrogenic activity in the water column. Twenty-three different pesticide residues were observed in one or more water s les from the 24 wetlands chemicals observed at more than 40% of sites were simazine (100%), atrazine (79%), and metalaxyl and terbutryn (46%). Using the toxicity unit (TU) concept, less than 15% of the detected pesticides were considered to pose an in idual, short-term risk to fish or zooplankton in the ponds and wetlands. However, one pesticide (fenvalerate) may have posed a possible short-term risk to fish (log10TUf > -3), and three pesticides (azoxystrobin, fenamiphos and fenvalerate) may have posed a risk to zooplankton (logTUzp between -2 and -3) all the photosystem II (PSII) inhibiting herbicides may have posed a risk to primary producers in the ponds and wetlands (log10TUap and/or log10TUalg > -3). The wetland sediments were contaminated with 16 different pesticides no chemicals were observed at more than one third of sites, but based on frequency of detection and concentrations, bifenthrin (33%, maximum 59 μg/kg) is the priority insecticide of concern for the sediments studied. Five sites returned a TU greater than the possible effect threshold (i.e. log10TU > 1) as a result of bifenthrin contamination of their sediments. Most sediments did not exceed Australian sediment quality guideline levels for trace metals. However, more than half of the sites had threshold effect concentration quotients (TECQ) values >1 for Cu (58%), Pb (50%), Ni (67%) and Zn (63%), and 75% of sites had mean probable effect concentration quotients (PECQ) >0.2, suggesting that the collected sediments may have been having some impact on sediment-dwelling organisms.
Publisher: Springer Science and Business Media LLC
Date: 23-11-2015
DOI: 10.1007/S11356-015-5795-6
Abstract: Water and sediment s les were collected from up to 17 sites in waterways entering the Corner Inlet Marine National Park monthly between November 2009 and April 2010, with the Chemcatcher passive s ler system deployed at these sites in November 2009 and March 2010. Trace metal concentrations were low, with none occurring at concentrations with the potential for adverse ecological effects. The agrochemical residues data showed the presence of a small number of pesticides at very low concentration (ng/L) in the surface waters of streams entering the Corner Inlet, and as widespread, but still limited contamination of sediments. Concentrations of pesticides detected were relatively low and several orders of magnitude below reported ecotoxicological effect and hazardous concentration values. The low levels of pesticides detected in this study indicate that agricultural industries were responsible agrochemical users. This research project is a rarity in aligning both agrochemical usage data obtained from chemical resellers in the target catchment with residue analysis of environmental s les. Based on frequency of detection and concentrations, prometryn is the priority chemical of concern for both the water and sediments studied, but this chemical was not listed in reseller data. Consequently, the risks may be greater than the field data would suggest, and priorities for monitoring different since some commonly used herbicides (such as glyphosate, phenoxy acid herbicides, and sulfonyl urea herbicides) were not screened. Therefore, researchers, academia, industry, and government need to identify ways to achieve a more coordinated land use approach for obtaining information on the use of chemicals in a catchment, their presence in waterways, and the longer term performance of chemicals, particularly where they are used multiple times in a year.
Publisher: Springer Science and Business Media LLC
Date: 26-03-2011
DOI: 10.1007/S00128-011-0251-X
Abstract: In this study, we compared the performance as screening tools of two yeast-based recombinant receptor-reporter gene bioassays with a commercial ELISA kit for measurement of total estrogens. For WWTP effluents there was a very good correlation between the measured total estrogen concentrations (ELISA) and estrogenic activity by the hERα bioassay (r(2)=0.93), but not for the medERα bioassay (r(2)=0.50). For freshwater s les, the correlations between bioassay response and ELISA ES measurements were very good (r(2)>0.95). There was no correlation between bioassay response and ELISA ES measurements for estuarine s les.
Publisher: Springer Science and Business Media LLC
Date: 26-10-2012
DOI: 10.1007/S00244-011-9710-Y
Abstract: Fungicides are regularly applied in horticultural production systems and may migrate off-site, potentially posing an ecological risk to surface waterways. However, few studies have investigated the fate of fungicides in horticultural catchments. This study investigated the presence of 24 fungicides at 18 sites during a 5-month period within a horticultural catchment in southeastern Australia. Seventeen of the 24 fungicides were detected in the waterways, with fungicides detected in 63% of spot water s les, 44% of surface sediment s les, and 44% of the passive s ler systems deployed. One third of the water s les contained residues of two or more fungicides. Myclobutanil, trifloxystrobin, pyrimethanil, difenoconazole, and metalaxyl were the fungicides most frequently detected, being present in 16-38% of the spot water s les. Iprodione, myclobutanil, pyrimethanil, cyproconazole, trifloxystrobin, and fenarimol were found at the highest concentrations in the water s les (> 0.2 μg/l). Relatively high concentrations of myclobutanil and pyrimethanil (≥ 120 μg/kg dry weight) were detected in the sediment s les. Generally the concentrations of the fungicides detected were several orders of magnitude lower than reported ecotoxicological effect values, suggesting that concentrations of in idual fungicides in the catchment were unlikely to pose an ecological risk. However, there is little information on the effects of fungicides, especially fungi and microbes, on aquatic ecosystems. There is also little known about the combined effects of simultaneous low-level exposure of multiple fungicides to aquatic organisms. Further research is required to adequately assess the risk of fungicides in aquatic environments.
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.AQUATOX.2015.09.019
Abstract: Despite the pivotal role sexual selection plays in population dynamics and broader evolutionary processes, the impact of chemical pollution on female mate choice is poorly understood. One group of chemical contaminants with the potential to disrupt the mechanisms of female mate choice is endocrine disrupting chemicals (EDCs) a broad class of environmental pollutants that can interfere with the endocrinology of organisms at extremely low concentrations. Recent research has revealed that estrogenic EDCs can affect female mate choice in fish, but the impact of androgenic EDC exposure is yet to be studied. To address this, we investigated the effects of an environmentally relevant concentration of trenbolone - an androgenic steroid used as a growth promoter in the cattle industry - on female mate choice in wild-caught guppies (Poecilia reticulata). We exposed male and female guppies to 17β-trenbolone for 21 days (measured concentration 4ng/L) via a flow-through system, and found that trenbolone-exposed female guppies spent less time associating with males, and were less choosy, compared to unexposed females. In contrast, trenbolone had no impact on male reproductive behavior or morphology. This is the first study to show that androgenic EDC exposure can disrupt female mate choice, highlighting the need for studies to investigate the behavioral impacts of environmental contaminants on both sexes.
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.AQUATOX.2014.02.001
Abstract: Freshwater environments are common repositories for the discharge of large volumes of domestic and industrial waste, particularly through wastewater effluent. One common group of chemical pollutants present in wastewater are endocrine disrupting chemicals (EDCs), which can induce morphological and behavioural changes in aquatic organisms. The aim of this study was to compare the reproductive behaviour and morphology of a freshwater fish, the mosquitofish (Gambusia holbrooki), collected from two sites (wastewater treatment plant (WWTP) and a putative pristine site). The mosquitofish is a sexually dimorphic livebearer with a coercive mating system. Males inseminate females using their modified anal fin as an intromittent organ. Despite this, females are able to exert some control over the success of male mating attempts by selectively associating with, or avoiding, certain males over others. Using standard laboratory assays of reproductive behaviour, we found that mosquitofish males living in close proximity to WWTP showed increased mating activity compared to those inhabiting a pristine site. More specifically, during behavioural trials in which males were allowed to interact with females separated by a transparent ider, we found that WWTP-males spent more time associating with females. Concordant with this, when males and females were subsequently allowed to interact freely, WWTP-males also spent more time chasing and orienting towards the females. As a result, females from both sites showed more interest towards the WWTP-site males. Male anal fin morphology, however, did not differ between sites. Our study illustrates that lifetime exposure to WWTP-effluents can greatly affect male behaviour. The results underscore the importance of behaviour as a potential tool for investigating unknown contaminants in the environment.
Publisher: Public Library of Science (PLoS)
Date: 03-05-2013
Publisher: Springer Science and Business Media LLC
Date: 06-09-2011
DOI: 10.1007/S00128-011-0394-9
Abstract: A pilot study was initiated to provide the first information on the recombinant receptor-reporter gene bioassay (hormonal) activity of freshwaters in Victoria. The project involved the collection of water s les from six stations on the main stem of the Yarra River in and upstream of the city of Melbourne, Australia in April 2008 and April 2009. S les were prepared for measurement of s le toxicity using a modified photobacterium test, genotoxicity using a high-throughput luminescent umu test method, and human and medaka estrogen receptor (hERα and medERα), retinoic acid receptor (RAR), aryl hydrocarbon receptor (AhR) and thyroid receptor (TR) assay activity using the relevant yeast-based bioassays. Most s les were only weakly or moderately toxic, with no relationship observed to location along the river. The data for 2008 suggests that at that time the Yarra River s les contained few compounds that were, in and of themselves, genotoxic. No estrogenic or thyroid, and <1 ng/L retinoic acid receptor activity was observed. AhR activity increased with progressed downstream. AhR activity was higher in April 2009 than at the same time in 2008, perhaps as a result of extensive bush fires in the catchment in the months immediately prior to s ling. About 24% of the total AhR activity observed was associated with suspended solids.
Publisher: Elsevier BV
Date: 05-2004
Publisher: Springer Science and Business Media LLC
Date: 08-2004
Publisher: Elsevier BV
Date: 02-1999
Publisher: Springer Science and Business Media LLC
Date: 21-09-2013
DOI: 10.1007/S11356-012-1188-2
Abstract: Sexually mature male mosquitofish (Gambusia holbrooki) were collected from various sites around Melbourne in 2009 to evaluate the performance of gonopodial indices as a biomarker for endocrine disruption in Melbourne's waterways. The mosquitofish indices assessed were body length (BL), gonopodial length (GL)/BL ratio, ray 4:6 ratio and the absence or presence of hooks and serrae, and these varied between sites. The study was complemented by measurements of estrogenic, retinoid, thyroid and aryl hydrocarbon (AhR) receptor activities of the water. Male mosquitofish were 16.3-21.5 mm in length, and although there was a statistically significant positive relationship showing that bigger fish had longer gonopodia than small fish (r2 = 0.52, p < 0.001), there were few significant differences in GL/BL ratio of fish between sites. Measured estrogenic activity was mostly in the range 0.1-1.7 ng/L EEQ, with one site having much higher levels (~12 ng/L EEQ). Aryl hydrocarbon (AhR) receptor activity was observed in all water s les (7-180 ng/L βNF EQ), although there was no consistent pattern in the level of AhR activity observed, i.e., 'clean' sites were as likely to return a high AhR activity response as urban or wastewater treatment plant (WWTP)-impacted sites. There was no correlation between measurements of receptor actvity and gonopodial length (GL):BL ratio and BL. We conclude that the mosquitofish gonopodia only fulfills part of the criteria for biomarker selection for screening. The mosquitofish indices assessed were cheap and easy-to-perform procedures however, there is no baseline data from the selected sites to evaluate whether differences in the morpholical indices observed at a site were a result of natural selection in the population or due to estrogenic exposure.
Publisher: Wiley
Date: 18-02-2014
DOI: 10.1002/IEAM.1503
Publisher: Elsevier BV
Date: 08-2006
DOI: 10.1016/J.CHEMOSPHERE.2005.12.067
Abstract: In recent times, the apparent population decline of the southern bent-wing bat (Miniopterus schreibersii bassanii) at Bat Cave, Naracoorte has been ascribed to pesticide use in the region, following the finding of organochlorine and orgaonophosphate insecticide residues in bat guano. Adult southern bent-wing bats were collected from Bat Cave and Starlight Cave in 2003. Organochlorine contaminants were detected in all carcass s les: p,p'-DDE was by far the most dominant contaminant with concentrations ranging from 11,000 to 59,000ngg(-1), followed by p,p'-DDT (110-1600ngg(-1)), p,p'-DDD (35-620ngg(-1)), summation operatorPCBs (33-490ngg(-1)), summation operatorchlordane and related compounds (7.9-270ngg(-1)), HCB (1.6-120ngg(-1)), HP epox. (3.1-230ngg(-1)), TCPMOH (3.8-38ngg(-1)), summation operatorHCHs (1.4-9.6ngg(-1)), and TCPMe (0.1-4.2ngg(-1)) (all values on lipid-weight basis). No significant difference in DDE, DDD, DDT, summation operatorDDT, summation operatorPCB, trans-chlordane, heptachlor epoxide, trans-nonachlor, alpha-HCH, beta-HCH, gamma-HCH, TCPMOH or TCPMe concentrations were observed either between sexes within sites, or between sites (p>0.05). However, there were significant differences in HCB and oxychlordane concentrations between sexes and between sites (p<0.05), between site differences in cis-nonachlor concentrations in male bats (p<0.05), and cis-chlordane concentrations between sexes at Starlight Cave, and between males of each site (p<0.05). There were also significant differences in the liver concentrations of some metals between sexes within sites (Ag, Cd, Co, Cu, Pb, Se, Zn), and between sites (Ag, Cd, Co, Cu, Hg, Pb, Se, V, Zn). Clustering or grouping of sites was observed when the OC data was expressed on a lipid-weight basis. These inter-site differences in OC concentrations reflect local exposure over a period of time, and do not unambiguously support any suggestion that we are witnessing incipient speciation. However, for conservation purposes, it may be prudent to assume that there are two sub-populations of M. s. bassani feeding in different locations in this region of southern Australia, rather than the single homogeneous population suggested by genetic studies.
No related grants have been discovered for Mayumi Allinson.