ORCID Profile
0000-0001-6789-4254
Current Organisation
The University of Canberra
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Environmental Science and Management | Ecological Impacts of Climate Change | Ecological Applications | Environmental Impact Assessment | Surfacewater Hydrology | Evolutionary Impacts of Climate Change | Freshwater Ecology | Environmental Monitoring | Conservation And Biodiversity | Environmental Impact Assessment | Freshwater Ecology |
ANZSRC Socio-Economic Objective (SEO)
Ecosystem Adaptation to Climate Change | Ecosystem Assessment and Management of Fresh, Ground and Surface Water Environments | Oil and Gas Extraction | Mountain and High Country Flora, Fauna and Biodiversity | Coal Mining and Extraction | Living resources (flora and fauna) | Land and water management | Mountain and High Country Land and Water Management | Fresh, Ground and Surface Water Flora, Fauna and Biodiversity | Ecosystem Assessment and Management of Mountain and High Country Environments
Related Links
Publications
Acute toxicity largely reflects the salinity sensitivity of stream macroinvertebrates derived using field distributions
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/MF05241
Abstract: Two types of salinity tolerance information are commonly used for assessing salinity risk to freshwater organisms. These are data from laboratory experiments, usually acute (≤96-h LC50) values, and field distributions. Both approaches have advantages and limitations, and their applicability to the formation of guidelines and assessment of risks is not clear. In the present study, the acute lethal tolerances (72-h LC50) and acute tolerance scores (ATS) of 37 macroinvertebrate families from Queensland, Australia, were compared with maximum field conductivities and previously derived salinity sensitivity scores (SSS). LC50 values were significantly correlated with maximal field conductivities and SSS. To investigate this relationship further, the changes in community structure related to an increase in salinity were assessed. A salinity index (SI) (based on cumulative SSS) and acute salinity index (ASI) (based on cumulative ATS) were calculated using an independent data set from south-east Queensland (429 s les) and compared with each other and actual conductivity levels. Both indices were significantly correlated with each other and followed a similar trend when plotted against actual conductivity. These results support the notion that salinity sensitivity of macroinvertebrates derived from acute toxicity experiments reflects sensitivities derived using field distributions. Definition of this relationship will allow the two sources of salinity sensitivity to be combined in a weight-of-evidence approach, resulting in a more robust data set with which to estimate safe salinity concentrations.
Single‐species acute lethal toxicity tests are not predictive of relative population and community effects of two salinity types
Publisher: Wiley
Date: 14-09-2021
DOI: 10.1002/LOL2.10208
Abstract: Human‐mediated salinity increases are occurring in freshwaters globally, with consequent negative effects on freshwater bio ersity. Salinity comprises multiple anions and cations. While total concentrations are typically used to infer effects, in idual ion concentrations and ion ratios are critical in determining effects. Moreover, estimates of toxicity from single‐species laboratory tests, may not accurately predict relative effects on populations and communities. Here, we compared salinity increases from synthetic marine salts and sodium bicarbonate in an outdoor mesocosm experiment in southeastern Australia. We found different effects of salt types on stream macroinvertebrates at the population and community levels, where similar effects were predicted from single‐species laboratory tests. Our results caution against the use of single‐species laboratory‐derived toxicological data to predict both environmentally safe salinity levels and the relative effects of different salt sources on freshwater bio ersity.
Is the integration of hormesis and essentiality into ecotoxicology now opening Pandora's Box?
Publisher: Elsevier BV
Date: 02-2008
DOI: 10.1016/J.ENVPOL.2007.04.019
Abstract: Hormesis and essentiality are likely real and common effects at the level of the in idual. However, the widespread incorporation of stimulatory effects into applications of ecotoxicology requires the acceptance of assumptions, value judgements and possibly lowering of water/sediment quality standards. There is also currently little data appropriate for considering hormetic effects in the ecotoxicological context. Except perhaps in the case of fitting concentration-response curves, it is not clear that incorporation of hormetic and essentiality type responses into ecotoxicology is necessary. Furthermore, its incorporation presents considerable intellectual and practical changes for ecotoxicology and could have unanticipated consequences.
Sensitivity of a Large and Representative Sample of Antarctic Marine Invertebrates to Metals
Publisher: Wiley
Date: 31-05-2019
DOI: 10.1002/ETC.4419
Abstract: There are limited data on the sensitivity to contaminants of marine organisms in polar regions. Consequently, assessments of the risk of contaminants to marine biota in polar environments typically include extrapolations from temperate and/or tropical species. This is problematic because the taxonomic composition of organisms differs between polar and temperate/tropical waters, and both the toxicity of chemicals and the physiology of organisms are very different at the stable low temperatures experienced in polar marine systems. Collecting high‐quality sensitivity data for a wide range of marine polar organisms using traditional toxicity assessment approaches is a time‐consuming and difficult process, especially in remote and hostile environments. We applied a rapid toxicity testing approach, which allowed a much larger number of species to be tested than would be possible with traditional toxicity test methods, albeit with lower replications and fewer exposure concentrations. With this rapid approach, sensitivity estimates are less precise, but more numerous. This is important when constructing species sensitivity distributions (SSDs), which aim to represent the sensitivity of communities. We determined the approximate sensitivity (4‐ and 10‐d median lethal concentration [LC50] values) of a large and representative s le of Antarctic marine invertebrates to copper (Cu), zinc (Zn), and cadmium (Cd). Up to 88 LC50 values (from 88 different taxa) were used in the construction of SSDs. The hazardous concentrations for 1% of taxa (HC1) based on 10‐d LC50 values were 37, 346, and 792 μg/L for Cu, Zn, and Cd, respectively. Our results provide a basis for estimating the risk of exposure to metals for a large representative s le of marine polar invertebrates. Environ Toxicol Chem 2019 :1560–1568. © 2019 SETAC
Climate change as a contributor to human conflict
Publisher: Springer Science and Business Media LLC
Date: 03-2018
Response of stream invertebrate communities to vegetation damage from overgrazing by exotic rabbits on subantarctic Macquarie Island
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/MF10317
Abstract: Widespread damage to vegetation on an isolated oceanic island (Macquarie Island), due to overgrazing (since 2002) by an expanding exotic rabbit population, could affect the nature of catchment runoff and result in changes to stream habitats and the composition of their invertebrate communities. To test this hypothesis, stream invertebrate communities that had been s led originally in 1992 (at 15 sites when rabbit numbers were historically low), were re-s led in 2008 (17 sites) and in 2010 (12 sites). The number of taxa recorded at each site was 25–36% lower in 2008 (7.4 taxa per site) and in 2010 (8.7 taxa) than in 1992 (11.6 taxa) and an abundance index showed a substantial decline across most taxa. Ordination indicated that composition at all sites changed markedly between years. The greatest compositional changes occurred at sites exposed to moderate or severe levels of vegetation damage, suggesting that stream invertebrates responded to habitat changes associated with increased grazing. An altered input of organic material into the streams as a result of vegetation damage may have been responsible. If communities of stream invertebrates on isolated islands are degraded, then composition may be altered permanently, unless refuges are available.
Effects of repeated salt pulses on ecosystem structure and functions in a stream mesocosm
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.SCITOTENV.2013.12.067
Abstract: Rivers and streams affected by mining activities often receive short-term sharp salinity increases due to water-soluble stockpiled materials being washed into receiving water bodies. We conducted a mesocosm study to explore the response of structural (diatom and stream invertebrate communities) and functional descriptors (chlorophyll a concentration, fungal biomass and leaf decomposition) to repeated short salinity pulses (3h of duration, with nominal electrical conductivities of 5, 10 and 15 mS cm(-1)), mimicking the exposure pattern occurring at salt-mine affected rivers. The experiment was conducted in 12 artificial flow-through stream systems over 16 days. The effect of the salt pulses on the ecosystem structure and functioning did not fully match most of our initial hypotheses, with the community response being weaker than predicted. The diatom community was, however, dominated by salt-tolerant species throughout the experiment, showing no consistent response to the treatment. The invertebrate response was associated with statistically significant changes in community structure (i.e. abundance of the different taxa) but no statistically significant changes in taxa richness. The salt pulses affected some functional descriptors of the ecosystem: fungal biomass exhibited a unimodal response to treatment magnitude, algal growth (i.e. chl a biomass) was h ered with increasing conductivity and leaf decomposition was significantly reduced in the high treatment.
The imperative need for nationally coordinated bioassessment of rivers and streams
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/MF15329
Abstract: Declining water quality and ecological condition is a typical trend for rivers and streams worldwide as human demands for water resources increase. Managing these natural resources sustainably is a key responsibility of governments. Effective water management policies require information derived from long-term monitoring and evaluation. Biological monitoring and assessment are critical for management because bioassessment integrates the biological, physical and chemical features of a waterbody. Investment in nationally coordinated riverine bioassessment in Australia has almost ceased and the foci of management questions are on more localised assessments. However, rivers often span political and administrative boundaries, and their condition may be best protected and managed under national policies, supported by a coordinated national bioassessment framework. We argue that a nationally coordinated program for the bioassessment of riverine health is an essential element of sustainable management of a nation’s water resources. We outline new techniques and research needed to streamline current arrangements to meet present-day and emerging challenges for coordinating and integrating local, regional and national bioassessment activities. This paper draws on international experience in riverine bioassessment to identify attributes of successful broad-scale bioassessment programs and strategies needed to modernise freshwater bioassessment in Australia and re-establish national broad-scale focus.
Is metal flocculation from mining activities a previously overlooked mechanism for impairing freshwater ecosystems?
Publisher: Elsevier BV
Date: 06-2019
Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?
Publisher: Elsevier BV
Date: 06-2004
Identifying sex-linked markers in Litoria aurea: a novel approach to understanding sex chromosome evolution in an amphibian
Publisher: Springer Science and Business Media LLC
Date: 12-11-2019
DOI: 10.1038/S41598-019-52970-4
Abstract: Few taxa exhibit the variability of sex-determining modes as hibians. However, due to the presence of homomorphic sex chromosomes in many species, this phenomenon has been difficult to study. The Australian frog, Litoria aurea , has been relatively well studied over the past 20 years due to widespread declines largely attributable to chytrid fungus. However, it has been subject to few molecular studies and its mode of sex determination remained unknown. We applied DArTseq™ to develop sex-linked single nucleotide polymorphisms (SNPs) and restriction fragment presence/absence (PA) markers in 44 phenotypically sexed L. aurea in iduals from the Molonglo River in NSW, Australia. We conclusively identified a male heterogametic (XX-XY) sex determination mode in this species, identifying 11 perfectly sex-linked SNP and six strongly sex-linked PA markers. We identified a further 47 moderately sex-linked SNP loci, likely serving as evidence indicative of XY recombination. Furthermore, within these 47 loci, a group of nine males were found to have a feminised Y chromosome that significantly differed to all other males. We postulate ancestral sex-reversal as a means for the evolution of this now pseudoautosomal region on the Y chromosome. Our findings present new evidence for the ‘fountain of youth’ hypothesis for the retention of homomorphic sex chromosomes in hibians and describe a novel approach for the study of sex chromosome evolution in hibia.
How benthic diatoms within natural communities respond to eight common herbicides with different modes of action
Publisher: Elsevier BV
Date: 07-2016
DOI: 10.1016/J.SCITOTENV.2016.03.142
Abstract: Herbicides are common pollutants of rivers in agricultural regions. These contaminants include various types of chemicals with different modes of toxic action. Herbicides can have toxic effects on freshwater benthic diatoms, the base of the aquatic food web. We examined the effects of (non-mixture) herbicide exposure to the health of diatoms for eight common herbicides with three different modes of action the photosystem II (PSII) inhibitors: atrazine, simazine, hexazinone, tebuthiuron and diuron two auxinic herbicides: MCPA and 2,4-D and the EPSP synthase inhibitor: glyphosate. Benthic diatoms within riverine communities were exposed to each herbicide in rapid toxicity tests at concentrations of 50, 200 and 500μgL(-1). The most sensitive taxa were Gomphonema spp. and Encyonema gracilis. Navicula cryptotenella was the most tolerant to herbicide exposure. There was no significant effect of the different herbicide modes of action at the community level. Herbicide mode of action did not alter which taxa were most sensitive within the community and sensitivity rankings of the dominant diatom taxa were similar for each of the eight herbicides. The consistency of the results between herbicides suggests that freshwater benthic diatoms may be suitable in situ indicators for detecting the toxicity of herbicides with differing modes of action.
Effects of spatial and temporal changes in water velocity on the density of the freshwater snail Potamopyrgus antipodarum (Gray)
Publisher: Informa UK Limited
Date: 1999
Thresholds for the Effects of Pesticides on Invertebrate Communities and Leaf Breakdown in Stream Ecosystems
Publisher: American Chemical Society (ACS)
Date: 10-04-2012
DOI: 10.1021/ES2039882
Abstract: We compiled data from eight field studies conducted between 1998 and 2010 in Europe, Siberia, and Australia to derive thresholds for the effects of pesticides on macroinvertebrate communities and the ecosystem function leaf breakdown. Dose-response models for the relationship of pesticide toxicity with the abundance of sensitive macroinvertebrate taxa showed significant differences to reference sites at 1/1000 to 1/10,000 of the median acute effect concentration (EC50) for Daphnia magna, depending on the model specification and whether forested upstream sections were present. Hence, the analysis revealed effects well below the threshold of 1/100 of the EC50 for D. magna incorporated in the European Union Uniform Principles (UP) for registration of single pesticides. Moreover, the abundances of sensitive macroinvertebrates in the communities were reduced by 27% to 61% at concentrations related to 1/100 of the EC50 for D. magna. The invertebrate leaf breakdown rate was positively linearly related to the abundance of pesticide-sensitive macroinvertebrate species in the communities, though only for two of the three countries examined. We argue that the low effect thresholds observed were not mainly because of an underestimation of field exposure or confounding factors. From the results gathered we derive that the UP threshold for single pesticides based on D. magna is not protective for field communities subject to multiple stressors, pesticide mixtures, and repeated exposures and that risk mitigation measures, such as forested landscape patches, can alleviate effects of pesticides.
Salinisation of rivers
Publisher: Elsevier BV
Date: 02-2013
DOI: 10.1016/J.ENVPOL.2012.10.011
Abstract: Secondary salinisation of rivers and streams is a global and growing threat that might be lified by climate change. It can have many different causes, like irrigation, mining activity or the use of salts as de-icing agents for roads. Freshwater organisms only tolerate certain ranges of water salinity. Therefore secondary salinisation has an impact at the in idual, population, community and ecosystem levels, which ultimately leads to a reduction in aquatic bio ersity and compromises the goods and services that rivers and streams provide. Management of secondary salinization should be directed towards integrated catchment strategies (e.g. benefiting from the dilution capacity of the rivers) and identifying threshold salt concentrations to preserve the ecosystem integrity. Future research on the interaction of salinity with other stressors and the impact of salinization on trophic interactions and ecosystem properties is needed and the implications of this issue for human society need to be seriously considered.
Salinity tolerance of riverine microinvertebrates from the southern Murray-Darling Basin
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/MF06046
Abstract: Concern about the effect of rising salinity on freshwater bio ersity has led to studies investigating the salt tolerance of macroinvertebrates and fish, with less attention given to microinvertebrates. We investigated the acute lethal effects of salinity on 12 microinvertebrate species from rivers in the southern Murray–Darling Basin in central Victoria, Australia. For a subset of these species, sub-lethal salinity effects and the effect of water temperature on salinity tolerance were also investigated. The most sensitive microinvertebrates had broadly similar 72-h LC50 values to the most sensitive macroinvertebrates, reported in other studies. However, the most tolerant microinvertebrates tested were much more sensitive than the most tolerant macroinvertebrates and the microinvertebrates studied were more sensitive than most freshwater fish. Temperature affected the acute lethal toxicity of salinity but only to a small degree. In three of four species (the exception being Hydra viridissima), the effects of salinity on growth, development and/or reproduction at concentrations below their 72-h LC50 values were observed. However, different endpoints responded differently to salinity. The demonstrated effect of salinity on microinvertebrates has the potential to indirectly affect fish and salt-tolerant macroinvertebrates via changes to their prey species or ecological functions performed by microinvertebrates.
Energetics as a lens to understanding aquatic insect's responses to changing temperature, dissolved oxygen and salinity regimes
Publisher: Elsevier BV
Date: 10-2020
Species of freshwater invertebrates that are sensitive to one saline water are mostly sensitive to another saline water but an exception exists
Publisher: The Royal Society
Date: 03-12-2019
Abstract: Coal mining and extraction of methane from coal beds generate effluent with elevated salinity or major ion concentrations. If discharged to freshwater systems, these effluents may have adverse environmental effects. There is a growing body of work on freshwater invertebrates that indicates variation in the proportion of major ions can be more important than salinity when determining toxicity. However, it is not known if saline toxicity in a subset of species is representative of toxicity across all freshwater invertebrates. If patterns derived from a subset of species are representative of all freshwater invertebrates, then we would expect a correlation in the relative sensitivity of these species to multiple saline waters. Here, we determine if there is a correlation between the acute (96 h) lethal toxicity in freshwater invertebrates to synthetic marine salts (SMS) and sodium bicarbonate (NaHCO 3 ) added to dechlorinated Sydney tap water. NaHCO 3 is a major component of many coal bed effluents. However, most salinization in Australia exhibits ionic composition similar to seawater, which has very little HCO 3 − . Across all eight species tested, NaHCO 3 was 2–50 times more toxic than SMS. We also observed strong correlations in the acute toxicity of seven of the tested species to SMS and NaHCO 3 . The strongest relationship (LC50 r 2 = 0.906) was dependent on the exclusion of one species, Paratya australiensis (Decopoda: Atyidae), which was the most sensitive species tested to NaHCO 3 , but the second-most tolerant of SMS. We conclude that differences in the toxicity of different proportions of major ions can be similar across a wide range of species. Therefore, a small subset of the invertebrate community can be representative of the whole. However, there are some species, which based on the species tested in the current study appear to be a minority, that respond differently to saline effluent and need to be considered separately. We discuss the implications of this study for the management of saline coal bed waters. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects'.
Salt in freshwaters: causes, effects and prospects - introduction to the theme issue
Publisher: The Royal Society
Date: 03-12-2021
Abstract: Humans are globally increasing the salt concentration of freshwaters (i.e. freshwater salinization), leading to significant effects at the population, community and ecosystem level. The present theme issue focuses on priority research questions and delivers results that contribute to shaping the future research agenda on freshwater salinization as well as fostering our capacity to manage salinization. The issue is structured along five topics: (i) the estimation of future salinity and evaluation of the relative contribution of the different drivers (ii) the physiological responses of organisms to alterations in ion concentrations with a specific focus on the osmophysiology of freshwater insects and the responses of different organisims to seawater intrusion (iii) the impact of salinization on ecosystem functioning, also considering the connections between riparian and stream ecosystems (iv) the role of context in moderating the response to salinization. The contributions scrutinise the role of additional stressors, biotic interactions, the identify of the ions and their ratios, as well as of the biogeographic and evolutionary context and (v) the public discourse on salinization and recommendations for management and regulation. In this paper we introduce the general background of salinization, outline research gaps and report key findings from the contributions to this theme issue. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.
Relative salinity tolerance of macroinvertebrates from the Barwon River, Victoria, Australia
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/MF02081
Abstract: Salinity levels are rising in many freshwater environments, yet there are few direct measurements of salinity tolerance of organisms likely to be salt sensitive. The relative salinity tolerance to artificial seawater of macroinvertebrates from the Barwon River in Victoria, Australia, was assessed by measuring the 72-h lethal concentrations required to kill 50% of in iduals (LC50). LC50 values ranged from an electrical conductivity of 5.5 to 76 mS cm–1 (mean 31 mS cm–1, n = 57) and followed a log-normal distribution. The most salt-sensitive groups tested were Baetidae (LC50 value range: 5.5–6.2 mS cm–1), Chironomidae (10 mS cm–1) and several soft-bodied non-arthropods (Oligochaeta, Gastropoda, Nematomorpha, Tricladida and Hirudinea 9–14 mS cm–1). Other groups, from least to most tolerant, were non-baetid Ephmeroptera ( .6–15 mS cm–1), Plecoptera ( .6– mS cm–1), Trichoptera (9– mS cm–1), Corixidae (18–26 mS cm–1), non-corixid Hemiptera (33–44 mS cm–1), Coleoptera (19–54 mS cm–1), Hydracarina (39 mS cm–1) and Odonata (30–55 mS cm–1), and macrocrustaceans (Decapoda, Isopoda and Amphipoda 38–76 mS cm–1).
Making species salinity sensitivity distributions reflective of naturally occurring communities: Using rapid testing and Bayesian statistics
Publisher: Wiley
Date: 11-2008
DOI: 10.1897/08-079.1
Abstract: Species sensitivity distributions (SSDs) may accurately predict the proportion of species in a community that are at hazard from environmental contaminants only if they contain sensitivity data from a large s le of species representative of the mix of species present in the locality or habitat of interest. With current widely accepted ecotoxicological methods, however, this rarely occurs. Two recent suggestions address this problem. First, use rapid toxicity tests, which are less rigorous than conventional tests, to approximate experimentally the sensitivity of many species quickly and in approximate proportion to naturally occurring communities. Second, use expert judgements regarding the sensitivity of higher taxonomic groups (e.g., orders) and Bayesian statistical methods to construct SSDs that reflect the richness (or perceived importance) of these groups. Here, we describe and analyze several models from a Bayesian perspective to construct SSDs from data derived using rapid toxicity testing, combining both rapid test data and expert opinion. We compare these new models with two frequentist approaches, Kaplan-Meier and a log-normal distribution, using a large data set on the salinity sensitivity of freshwater macroinvertebrates from Victoria (Australia). The frequentist log-normal analysis produced a SSD that overestimated the hazard to species relative to the Kaplan-Meier and Bayesian analyses. Of the Bayesian analyses investigated, the introduction of a weighting factor to account for the richness (or importance) of taxonomic groups influenced the calculated hazard to species. Furthermore, Bayesian methods allowed us to determine credible intervals representing SSD uncertainty. We recommend that rapid tests, expert judgements, and novel Bayesian statistical methods be used so that SSDs reflect communities of organisms found in nature.
Salinized rivers
Publisher: The Royal Society
Date: 03-2016
Abstract: Anthropogenic salinization of rivers is an emerging issue of global concern, with significant adverse effects on bio ersity and ecosystem functioning. Impacts of freshwater salinization on biota are strongly mediated by evolutionary history, as this is a major factor determining species physiological salinity tolerance. Freshwater insects dominate most flowing waters, and the common lotic insect orders Ephemeroptera (mayflies), Plecoptera (stoneflies) and Trichoptera (caddisflies) are particularly salt-sensitive. Tolerances of existing taxa, rapid adaption, colonization by novel taxa (from naturally saline environments) and interactions between species will be key drivers of assemblages in saline lotic systems. Here we outline a conceptual framework predicting how communities may change in salinizing rivers. We envision that a relatively small number of taxa will be saline-tolerant and able to colonize salinized rivers (e.g. most naturally saline habitats are lentic thus potential colonizers would need to adapt to lotic environments), leading to depauperate communities in these environments.
Stressor dominance and sensitivity‐dependent antagonism: Disentangling the freshwater effects of an insecticide among co‐occurring agricultural stressors
Publisher: Wiley
Date: 21-06-2019
Global Scale Variation in the Salinity Sensitivity of Riverine Macroinvertebrates: Eastern Australia, France, Israel and South Africa
Publisher: Public Library of Science (PLoS)
Date: 02-05-2012
Multiple anthropogenic stressors have inconsistent cumulative effects across a large spatial gradient
Publisher: California Digital Library (CDL)
Date: 09-12-2021
Comparing test systems to measure the salinity tolerance of freshwater invertebrates
Publisher: Academy of Science of South Africa
Date: 18-11-2004
Benthic diatoms as indicators of herbicide toxicity in rivers – A new SPEcies At Risk (SPEARherbicides) index
Publisher: Elsevier BV
Date: 04-2019
Post-Cranial Skeletons of Hypothyroid Cretins Show a Similar Anatomical Mosaic as Homo floresiensis
Publisher: Public Library of Science (PLoS)
Date: 27-09-2010
A similarity‐index–based method to estimate chemical concentration limits protective for ecological communities
Publisher: Wiley
Date: 04-08-0171
DOI: 10.1002/ETC.256
Abstract: A new method is presented to determine retrospectively proportional changes of species composition in a community at risk from particular concentrations of chemical stressors. The method makes estimates with some similarities to those claimed by species sensitivity distributions (SSDs) but is based on species presence/absence field data and requires assumptions that are more likely to be met. The method uses Jaccard's index (JI), the proportion of species in common to two s les. At a similar level of contamination, the occurrence of species is usually highly variable, and thus JI values between in idual pairs of s les can be low. However, by pooling s les with a similar contamination level, an increasingly complete set of species present at this level of contamination is gained. Our method involves calculating JI between randomly selected groups of s les (pooled s le sets) with similar and different levels of contamination. It then relates changes in JI to the difference in contamination and produces estimates of the proportional change in species between preselected categories of contamination. The application of the method is illustrated by using data on riverine freshwater macroinvertebrates exposed to salinity in southeastern Australia pesticide runoff potential in the Aller River Catchment, Germany and metal pollution (principle Cu) in the Clark Fork River Catchment, Montana, USA.
Slow recovery of stream invertebrates on subantarctic Macquarie Island after eradication of introduced rabbits and regrowth of vegetation
Publisher: CSIRO Publishing
Date: 22-08-2023
DOI: 10.1071/MF23009
Continuation of opioid replacement program delivery in the aftermath of cyclones in Queensland, Australia: A qualitative exploration of the perspectives of pharmacists and opioid replacement therapy s
Publisher: Elsevier BV
Date: 08-2020
DOI: 10.1016/J.SAPHARM.2019.11.007
Abstract: Cyclones can significantly impact on communities and their healthcare services. Community members with chronic diseases, including opioid dependence, who rely on these healthcare services are placed at an increased risk of treatment disruption during a disaster event. Disruptions to the continuity of the opioid replacement therapy (ORT) service can potentially lead to relapse, withdrawal, and risky behaviours in clients with potential repercussions for the community. To explore the effects of Queensland (QLD) cyclones on opioid treatment programs within Queensland community and hospital pharmacies from three perspectives. Qualitative research methods were used. Participants comprised five community pharmacists, four Queensland opioid treatment program (QOTP) employees, and five public hospital pharmacists. Participants were identified as they had worked in Townsville, Rockh ton, Mackay, or Yeppoon in a community impacted by a cyclone and involved with ORT supply. Interviews were recorded and data were analysed by two methods - manual coding and the text analytics software Leximancer®. The two themes that emerged from the manual coding process were 'disaster preparedness' and 'continuity of service'. The key themes from the Leximancer® analysis aligned with the two manual coding themes with no new themes identified. Primary dosing site closures in disaster-affected areas led to increased pressures on hospitals and other community pharmacy dosing sites to supply ORT doses to clients. However, a lack of dosing information available to pharmacists and strict legislative requirements made continuity of ORT supply during these cyclones difficult. Continuation of ORT services during and in the aftermath of a cyclone event is complex. This research highlighted a need for a coordination of efforts and shared dosing information between QOTP employees, community pharmacists, and hospital pharmacists. To improve continuity of ORT services, it is essential that these stakeholders engage with each other in preparing for and responding to future events.
Can SPEcies At Risk of pesticides (SPEAR) indices detect effects of target stressors among multiple interacting stressors?
Publisher: Elsevier BV
Date: 04-2021
Risk assessment of salinity and turbidity in Victoria (Australia) to stream insects' community structure does not always protect functional traits
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.SCITOTENV.2011.05.056
Abstract: Ecological risk assessments mostly consider measures of community composition (structure) across large spatial scales. These assessments, using species sensitivity distributions (SSDs) or the relative species retention (RSR), may not be protective of ecosystem functions and services at smaller spatial scales. Here we examine how changes in biological traits, as proxy for ecosystem functions/services, at a fine spatial scale relate to larger scale assessment of structure. We use functional traits of stream insect species in south-east Australia in two habitats (riffle and edge ool). We find that the protection of community structure in terms of 95% of species over multiple sites against adverse effects of salinity (as electrical conductivity) and turbidity will mostly, but not always, protect traits at smaller scales. Considering different combinations of trait modalities, contaminants and habitat, a mean of 17.5% (range 0%-36.8) of cases would result in under-protection of trait modalities despite protecting species composition (in terms of Jaccard's Index). This under-protection of trait modalities is only because of the different spatial scales that community structure and the traits were considered. We recommend that where the protection of biological traits, ecosystem functions or ecosystem services from stressors is a management goal, protective targets should not be solely set using measures of community structure such as SSDs or RSR. To protect both structural and functional attributes separate risk assessments should be done.
Constructing Time-Resolved Species Sensitivity Distributions Using a Hierarchical Toxico-Dynamic Model
Publisher: American Chemical Society (ACS)
Date: 08-10-2015
Abstract: Classical species sensitivity distribution (SSD) is used to assess the threat to ecological communities posed by a contaminant and derive a safe concentration. It suffers from several well-documented weaknesses regarding its ecological realism and statistical soundness. Criticism includes that SSD does not take time-dependence of the data into account, that safe concentrations obtained from SSD might not be entirely protective of the target communities, and that there are issues of statistical representativity and of uncertainty propagation from the experimental data. We present a hierarchical toxico-dynamic (TD) model to simultaneously address these weaknesses: TD models incorporate time-dependence and allow improvement of the ecological relevance of safe concentrations, while the hierarchical approach affords appropriate propagation of uncertainty from the original data. We develop this model on a published data set containing the salinity tolerance over 72 h of 217 macroinvertebrate taxa, obtained through rapid toxicity testing (RTT). The shrinkage properties of the hierarchical model prove particularly adequate for modeling inhomogeneous RTT data. Taking into account the large variability in the species response, the model fits the whole data set well. Moreover, the model predicts a time-independent safe concentration below that obtained with classical SSD at 72 h, demonstrating under-protectiveness of the classical approach.
Bicarbonate alone does not totally explain the toxicity from major ions of coal bed derived waters to freshwater invertebrates
Publisher: Springer Science and Business Media LLC
Date: 14-06-2022
DOI: 10.1007/S10646-022-02552-4
Abstract: Concentrations of major ions in coal mine discharge waters and unconventional hydrocarbon produced waters derived from coal bed methane (CBM) production, are potentially harmful to freshwater ecosystems. Bicarbonate is a major constituent of produced waters from CBM and coal mining. However, little is known about the relative toxicity of differing ionic proportions, especially bicarbonate, found in these CBM waters. As all freshwater invertebrates tested are more acutely sensitive to sodium bicarbonate (NaHCO 3 ) than sodium chloride (NaCl) or synthetic sea water, we tested the hypotheses that toxicity of CBM waters are driven by bicarbonate concentration, and waters containing a higher proportion of bicarbonate are more toxic to freshwater invertebrates than those with less bicarbonate. We compared the acute (96 h) lethal toxicity to six freshwater invertebrate species of NaHCO 3 and two synthetic CBM waters, with ionic proportions representative of water from CBM wells across New South Wales (NSW) and Queensland (Qld), in Australia. The ranking of LC50 values expressed as total salinity was consistent with the hypotheses. However, when toxicity was expressed as bicarbonate concentration, the hypothesis that the toxicity of coal bed waters would be explained by bicarbonate concentration was not well supported, and other ionic components were either ameliorating or exacerbating the NaHCO 3 toxicity. Our findings showed NaHCO 3 was more toxic than NaCl and that the NaHCO 3 proportion of synthetic CBM waters drives toxicity, however other ions are altering the toxicity of bicarbonate.
Fish and macroinvertebrate assemblages reveal extensive degradation of the world's rivers.
Publisher: Wiley
Date: 17-10-2022
DOI: 10.1111/GCB.16439
Abstract: Rivers suffer from multiple stressors acting simultaneously on their biota, but the consequences are poorly quantified at the global scale. We evaluated the biological condition of rivers globally, including the largest proportion of countries from the Global South published to date. We gathered macroinvertebrate- and fish-based assessments from 72,275 and 37,676 sites, respectively, from 64 study regions across six continents and 45 nations. Because assessments were based on differing methods, different systems were consolidated into a 3-class system: Good, Impaired, or Severely Impaired, following common guidelines. The proportion of sites in each class by study area was calculated and each region was assigned a Köppen-Geiger climate type, Human Footprint score (addressing landscape alterations), Human Development Index (HDI) score (addressing social welfare), % rivers with good ambient water quality, % protected freshwater key bio ersity areas and % of forest area net change rate. We found that 50% of macroinvertebrate sites and 42% of fish sites were in Good condition, whereas 21% and 29% were Severely Impaired, respectively. The poorest biological conditions occurred in Arid and Equatorial climates and the best conditions occurred in Snow climates. Severely Impaired conditions were associated (Pearson correlation coefficient) with higher HDI scores, poorer physico-chemical water quality, and lower proportions of protected freshwater areas. Good biological conditions were associated with good water quality and increased forested areas. It is essential to implement statutory bioassessment programs in Asian, African, and South American countries, and continue them in Oceania, Europe, and North America. There is a need to invest in assessments based on fish, as there is less information globally and fish were strong indicators of degradation. Our study highlights a need to increase the extent and number of protected river catchments, preserve and restore natural forested areas in the catchments, treat wastewater discharges, and improve river connectivity.
The thermal breadth of temperate and tropic freshwater insects supports the Climate Variability Hypothesis
Publisher: Authorea, Inc.
Date: 16-08-2023
DOI: 10.22541/AU.169219473.35826889/V1
Abstract: Climate change involves increases in mean temperature and changes in temperature variability at multiple temporal scales. Research on species response to climate change has focussed on changes in mean temperature. Thus, there is a need to consider how species will respond to changes in temperature variability. The Climate Variability Hypothesis (CVH) provides a conceptual framework for exploring potential effects of annual scale thermal variability across climatic zones. The CVH predicts ectotherms in temperate regions tolerate a wider range of temperatures than those in tropical regions in response to greater annual variability in temperate regions. However, various other aspects of thermal regimes (e.g. diel variability), organisms’ size and taxonomic identity may also influence thermal tolerance. Indeed, high temperatures in the tropics have been proposed as constraining organisms’ ability to tolerate a wide range of temperatures, implying that high annual maximum temperatures would be associated with tolerating a narrow range of temperatures. We measured thermal regimes and critical thermal limits (CTmax and CTmin) of insects in the orders Ephemeroptera (mayflies), Plecoptera (stoneflies) and Trichoptera (caddisflies) along elevation gradients in streams in temperate and tropical regions of eastern Australia and tested the CVH by determining which variables were most correlated with thermal breadth (Tbr = CTmax - CTmin). Consistent with the CVH, Tbr tended to increase with increasing annual temperature range and increasing body size. Tbr was generally wider in Plecoptera than in Ephemeroptera or Trichoptera. We found no evidence that higher annual maximum temperature constrained in iduals’ abilities to tolerate a wide range of temperatures. The support for the CVH we document, suggests that temperate organisms may be able to tolerate wider range of temperatures than tropical organisms. There is an urgent need to investigate other aspects of thermal regimes, such as diel temperature cycling and minimum temperature.
The Effects of Road De-icing Salts on Water Quality and Macroinvertebrates in Australian Alpine Areas
Publisher: Springer Science and Business Media LLC
Date: 20-04-2021
DOI: 10.1007/S00244-021-00827-1
Abstract: The application of road de-icing salts has the potential to salinize fresh waters and degrade habitat for aquatic organisms. In the Australian Alps, the ecological effects of even small salinity increases from de-icing may be different than in North America and Europe because of (1) differences in the evolutionary history, and (2) areas with de-icing in Australia are not located in urbanized landscapes where de-icing has been largely studied elsewhere. In this study, we tried to determine the salinity increases attributable to de-icing in Australia and the effects of this increase in salinity to stream macroinvertebrates. We observed increased salt concentrations (as measured by continuous measurements of electrical conductivity (EC) and periodic measurements of chloride concentrations) in streams near two Australian ski resorts, during the snow seasons (June to September) of 2016 to 2018. The maximum EC observed in streams in salted sites near Perisher, New South Wales, was 390 µS cm
The cumulative impacts of anthropogenic stressors vary markedly along environmental gradients
Publisher: Wiley
Date: 26-09-2023
DOI: 10.1111/GCB.16435
Abstract: Understanding the cumulative effects of multiple stressors on bio ersity is key to managing their impacts. Stressor interactions are often studied using an additive/antagonistic/synergistic typology, aimed at identifying situations where in idual stressor effects are reduced or lified when they act in combination. Here, we analysed variation in the family richness of stream macroinvertebrates in the groups Ephemeroptera, Plecoptera and Trichoptera (EPT) at 4658 sites spanning a 32° latitudinal range in eastern Australia in relation to two largely human‐induced stressors, salinity and turbidity, and two environmental gradients, temperature and slope. The cumulative and interactive effect of salinity and turbidity on EPT family richness varied across the landscape and by habitat (edge or riffle) such that we observed additive, antagonistic and synergistic outcomes depending on the environmental context. Our findings highlight the importance of understanding the consistency of multiple stressor impacts, which will involve higher‐order interactions between multiple stressors and environmental factors.
Status and Causal Pathway Assessments Supporting River Basin Management
Publisher: Springer Berlin Heidelberg
Date: 10-07-2013
Interactions among stressors may be weak
Publisher: Wiley
Date: 25-03-2018
DOI: 10.1111/DDI.12737
Chronic effects of atrazine exposure and recovery in freshwater benthic diatoms from two communities with different pollution histories
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.AQUATOX.2017.06.013
Abstract: Diffuse agricultural runoff into rivers can result in contamination with herbicides for prolonged periods of time. Chronic exposure to herbicides has the potential to alter toxic impacts in primary producers such as benthic diatoms. Determining how in idual diatom taxa respond to herbicide exposure over varied exposure durations is essential for assessing herbicide impacts. This study investigated the responses of various benthic diatom taxa and effects at the community level over 12days of atrazine exposure. Diatom communities were collected from two sites with differing exposure histories a relatively unpolluted site (Alligator Creek) and an agricultural stream (Barratta Creek) known to be polluted by atrazine and other herbicides. Diatom community composition and the proportion of healthy cells per taxon were assessed at 0, 2, 3, 6, 9 and 12days of atrazine exposure. Pollution history altered the response of the diatom community to atrazine exposure. In the Alligator Creek diatom community there was a shift in composition towards more tolerant taxa and the loss of sensitive taxa in atrazine exposed treatments. The sensitive taxon (Gomphonema truncatum) was consistently affected by atrazine toxicity. Conversely, the polluted Barratta Creek diatom community was not strongly affected by atrazine exposure. Our study shows that during chronic atrazine exposure some taxa demonstrated the ability to recover despite initial toxicity response. Recovery could be an important trait for understanding the ecological effect of herbicide exposure on diatom species in nature and in applied circumstances such as biomonitoring indices.
The salinity tolerance of eggs and hatchlings of selected aquatic macroinvertebrates in south-east Australia and South Africa
Publisher: Springer Science and Business Media LLC
Date: 04-2004
Effects of salinity on leaf breakdown: Dryland salinity versus salinity from a coalmine
Publisher: Elsevier BV
Date: 08-2016
DOI: 10.1016/J.AQUATOX.2016.06.014
Abstract: Salinization of freshwater ecosystems as a result of human activities represents a global threat for ecosystems' integrity. Whether different sources of salinity with their differing ionic compositions lead to variable effects in ecosystem functioning is unknown. Therefore, the present study assessed the impact of dryland- (50μS/cm to 11,000μS/cm) and coalmine-induced (100μS/cm to 2400μS/cm) salinization on the leaf litter breakdown, with focus on microorganisms as main decomposer, in two catchments in New South Wales, Australia. The breakdown of Eucalyptus camaldulensis leaves decreased with increasing salinity by up to a factor of three. Coalmine salinity, which is characterised by a higher share of bicarbonates, had a slightly but consistently higher breakdown rate at a given salinity relative to dryland salinity, which is characterised by ionic proportions similar to sea water. Complementary laboratory experiments supported the stimulatory impact of sodium bicarbonates on leaf breakdown when compared to sodium chloride or artificial sea salt. Furthermore, microbial inoculum from a high salinity site (11,000μS/cm) yielded lower leaf breakdown at lower salinity relative to inoculum from a low salinity site (50μS/cm). Conversely, inoculum from the high salinity site was less sensitive towards increasing salinity levels relative to inoculum from the low salinity site. The effects of the different inoculum were the same regardless of salt source (sodium bicarbonate, sodium chloride and artificial sea salt). Finally, the microorganism-mediated leaf litter breakdown was most efficient at intermediate salinity levels (≈500μS/cm). The present study thus points to severe implications of increasing salinity intensities on the ecosystem function of leaf litter breakdown, while the underlying processes need further scrutiny.
Is there an interaction of the effects of salinity and pesticides on the community structure of macroinvertebrates?
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.SCITOTENV.2012.07.066
Abstract: Salinization of freshwater ecosystems is a global problem affecting many regions worldwide and can co-occur with pesticides in agricultural regions. Given that both stressors are potent to affect macroinvertebrate communities, their effects could interact. We investigated the effects of salinity and pesticides at 24 sites in an agricultural region of southern Victoria, South-East Australia. We used distance-based redundancy analysis to determine the influence of pesticides, salinity and other environmental variables on the composition of macroinvertebrate communities. Salinity and pesticide toxicity had a statistically significant effect on communities as had the substrate composition and the percentage of pool and riffle sections in the s led stream reaches. We did not find evidence for interactive effects between salinity and pesticides, i.e. the effect of one of these variables did not depend on the level of the other. Nevertheless, our results show that salinization and exposure to pesticides can be major factors for the structure of macroinvertebrate communities in agricultural regions. Pesticide toxicity acted on a lower taxonomic level compared to salinity, potentially indicating evolutionary adaptation to salinity stress.
Metal toxicity affects predatory stream invertebrates less than other functional feeding groups
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.ENVPOL.2017.05.017
Abstract: Ecosystem effects of heavy metals need to be identified for a retrospective risk assessment, and potential impacts need to be predicted for a prospective risk assessment. In this study, we established a strong correlation between the toxic pressure of dissolved metals and invertebrate species. We compiled available data from a wide geographical range of Australian streams that were contaminated with heavy metals [mainly copper (Cu) and zinc (Zn)] and the corresponding invertebrate communities. Heavy metal toxicity is positively related to the proportion of predators within the invertebrate community, represented by the predator
Risk assessment using the species sensitivity distribution method: Data quality versus data quantity
Publisher: Wiley
Date: 25-04-2013
DOI: 10.1002/ETC.2190
Abstract: Species sensitivity distributions (SSDs) are cumulative distributions of measures of species sensitivity to a stressor or toxicant, and are used to estimate concentrations that will protect p% of a community (PCp ). There is conflict between the desire to use high-quality sensitivity data in SSDs, and to construct them with a large number of species forming a representative s le. Trade-offs between data quality and quantity were investigated using the effects of increasing salinity on the macroinvertebrate community from the Hunter River catchment, in eastern Australia. Five SSDs were constructed, representing five points along a continuum of data quality versus data quantity and representativeness. This continuum was achieved by the various inclusion/exclusion of censored data, nonmodeled data, and extrapolation from related species. Protective concentrations were estimated using the Burr type III distribution, Kaplan-Meier survival function, and two Bayesian statistical models. The dominant taxonomic group was the prime determinant of protective concentrations, with an increase in PC95 values resulting from a decrease in the proportion of Ephemeropteran species included in the SSD. In addition, decreases in data quantity in a SSD decreased community representativeness. The authors suggest, at least for salinity, that the inclusion of right censored data provides a more representative s le of species that reflects the natural biotic assemblage of an area to be protected, and will therefore improve risk assessment.
Why are mayflies (Ephemeroptera) lost following small increases in salinity? Three conceptual osmophysiological hypotheses
Publisher: The Royal Society
Date: 03-12-2019
Abstract: The salinity of many freshwaters is increasing globally as a result of human activities. Associated with this increase in salinity are losses of Ephemeroptera (mayfly) abundance and richness. The salinity concentrations at which Ephemeroptera decline in nature are lower than their internal salinity or haemolymph osmolality. Many species also suffer substantial mortality in single species laboratory toxicity tests at salinities lower than their internal salinity. These findings are problematic as conventional osmoregulation theory suggests that freshwater animals should not experience stress where external osmolality is greater than haemolymph osmolality. Here I explore three hypotheses to explain salt sensitivity in Ephemeroptera. These conceptual hypotheses are based on the observations that as the external sodium ion (Na + ) concentration increases so does the Na + turnover rate (both uptake and elimination rates increase). Sulphate ( ) uptake in mayflies also increases with increasing external although, unlike Na + , its rate of increase decreases with increasing external . The first hypothesis is premised on ion turnover being energetically costly. The first hypothesis proposes that in iduals must devote a greater proportion of their energy to ion homeostasis at the expense of other uses including growth and development. Lethal levels of salinity presumably result from in iduals not being able to devote enough energy to maintain ion homeostasis without critical loss of other vital functions. The second hypothesis is premised on the uptake of Na + exchanged for (an outgoing) H + , leading to (localized) loss of pH regulation. The third hypothesis is premised on localized Na + toxicity or poisoning with increased Na turnover as salinity increases. None of the proposed hypotheses is without potential problems, yet all are testable, and research effort should be focused at attempting to falsify them. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.
Biological interactions mediate context and species-specific sensitivities to salinity
Publisher: The Royal Society
Date: 03-12-2019
Abstract: Toxicants have both sub-lethal and lethal effects on aquatic biota, influencing organism fitness and community composition. However, toxicant effects within ecosystems may be altered by interactions with abiotic and biotic ecosystem components, including biological interactions. Collectively, this generates the potential for toxicant sensitivity to be highly context dependent, with significantly different outcomes in ecosystems than laboratory toxicity tests predict. We experimentally manipulated stream macroinvertebrate communities in 32 mesocosms to examine how communities from a low-salinity site were influenced by interactions with those from a high-salinity site along a gradient of salinity. Relative to those from the low-salinity site, organisms from the high-salinity site were expected to have greater tolerance and fitness at higher salinities. This created the potential for both salinity and tolerant-sensitive organism interactions to influence communities. We found that community composition was influenced by both direct toxicity and tolerant-sensitive organism interactions. Taxon and context-dependent responses included: (i) direct toxicity effects, irrespective of biotic interactions (ii) effects that were owing to the addition of tolerant taxa, irrespective of salinity (iii) toxicity dependent on sensitive-tolerant taxa interactions and (iv) toxic effects that were increased by interactions. Our results reinforce that ecological processes require consideration when examining toxicant effects within ecosystems. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.
Saving freshwater from salts
Publisher: American Association for the Advancement of Science (AAAS)
Date: 26-02-2016
Abstract: Ion-specific standards are needed to protect bio ersity
Understanding salt-tolerance and biota–stressor interactions in freshwater invertebrate communities
Publisher: CSIRO Publishing
Date: 21-10-2021
DOI: 10.1071/MF21164
Abstract: Salinity is increasing in many naturally fresh waters because of human activities, and there are concerns about the ecological effects of these increases. Salinity, as with any stressor, can affect organisms both directly and indirectly. In a previous study (Bray et al. 2019), we evaluated the relative importance of direct and indirect effects of increased salinity on stream invertebrates. Chessman (2021) criticised that study, claiming that the biotic treatments were confounded and did not directly test the hypotheses. Chessman (2021) also conducted a reanalysis of the data. We show through the analysis of new data that our biotic treatments were not confounded and that the conclusions made by Chessman (2021) were probably a consequence of the low statistical power of his analysis. Consequently, we argue that Chessman’s (2021) comments do not substantively alter the conclusions of our study, and we provide more evidence to support the conclusions of our previous publication. The study of biota–stressor interactions is increasingly relevant to a wide range of global ecosystems. There is a need to develop tractable experimental and survey designs that address these problems, and we identify further avenues for study of these complex issues.
Risk assessment of episodic exposures to chemicals should consider both the physiological and the ecological sensitivities of species
Publisher: Elsevier BV
Date: 12-2012
DOI: 10.1016/J.SCITOTENV.2012.09.047
Abstract: In flowing water pollution regularly occurs in short pulses (hours to days). Populations of species affected by pulses have the potential to recover in the absence of further disturbance but recovery rates will vary between species due to resilience (e.g. generation time and dispersal ability) and avoidance traits. Current assessments of the risks of chemicals to community structure--predominantly based on species sensitivity distributions (SSDs)--only consider physiological sensitivity and do not give any consideration as to the rate at which populations will recover. We constructed SSDs of ecologically sensitive and tolerant stream invertebrate assemblages (based on 3 traits previously shown to be important in determining how species relative abundances respond to pesticide toxicity) from south-east Australia and in regions of Finland, Germany and France. There were differences in SSDs of a generic measure of physiological sensitivity to organic chemicals between ecologically sensitive and tolerant species, though these differences were not consistent between the regions studied. We conclude that it is important for community level risk assessments of pulses of chemicals that the ecological sensitivity of the regional species assemblage is considered and discuss several options as to how this could be achieved.
An integrated database of stream macroinvertebrate traits for Australia: concept and application
Publisher: Elsevier BV
Date: 07-2020
Acute, diel, and annual temperature variability and the thermal biology of ectotherms
Publisher: Wiley
Date: 10-10-2022
DOI: 10.1111/GCB.16453
Abstract: Global warming is increasing mean temperatures and altering temperature variability at multiple temporal scales. To better understand the consequences of changes in thermal variability for ectotherms it is necessary to consider thermal variation at different time scales (i.e., acute, diel, and annual) and the responses of organisms within and across generations. Thermodynamics constrain acute responses to temperature, but within these constraints and over longer time periods, organisms have the scope to adaptively acclimate or evolve. Yet, hypotheses and predictions about responses to future warming tend not to explicitly consider the temporal scale at which temperature varies. Here, focusing on multicellular ectothermic animals, we argue that consideration of multiple processes and constraints associated with various timescales is necessary to better understand how altered thermal variability because of climate change will affect ectotherms.
Pesticides reduce regional biodiversity of stream invertebrates
Publisher: Proceedings of the National Academy of Sciences
Date: 17-06-2013
Abstract: The bio ersity crisis is one of the greatest challenges facing humanity, but our understanding of the drivers remains limited. Thus, after decades of studies and regulation efforts, it remains unknown whether to what degree and at what concentrations modern agricultural pesticides cause regional-scale species losses. We analyzed the effects of pesticides on the regional taxa richness of stream invertebrates in Europe (Germany and France) and Australia (southern Victoria). Pesticides caused statistically significant effects on both the species and family richness in both regions, with losses in taxa up to 42% of the recorded taxonomic pools. Furthermore, the effects in Europe were detected at concentrations that current legislation considers environmentally protective. Thus, the current ecological risk assessment of pesticides falls short of protecting bio ersity, and new approaches linking ecology and ecotoxicology are needed.
What is meant by 95% of species? an argument for the inclusion of rapid tolerance testing
Publisher: Informa UK Limited
Date: 10-2005
A trait database of stream invertebrates for the ecological risk assessment of single and combined effects of salinity and pesticides in South-East Australia
Publisher: Elsevier BV
Date: 05-2011
DOI: 10.1016/J.SCITOTENV.2011.01.053
Abstract: We compiled a database on a priori selected traits for South-East Australian freshwater macroinvertebrate families and used this data for the development of a biotic indicator for the detection of the effects of salinisation on freshwater communities (SPEAR(salinity)) and for the adaptation of the existing SPEAR(pesticides) index for South-East Australian taxa. The SPEAR(salinity) indicator showed a reasonably high relationship (0.38≤r(2)≤0.5) with salinity in terms of logarithmic electrical conductivity (log EC) using field biomonitoring data from 835 pools and riffle sites in Victoria and South Australia. Several other biotic indexes that were calculated for comparison purpose exhibited a lower relationship with log EC. In addition, SPEAR(salinity) was the only indicator that did not respond to other water quality variables and was therefore most selective. We used log EC data and modelled pesticide exposure for sites in Victoria in concert with SPEAR(salinity) and the existing SPEAR(pesticides) index to assess whether pesticides interacts with effects of salinity on invertebrate communities and vice versa. No interaction with pesticides was found for the effect of log EC on SPEAR(salinity), whereas EC interacted with the estimated pesticide exposure on the invertebrate communities. To foster the development of further trait-based ecological indicators, we suggest a conceptual model that predicts response traits based on the disturbance regime and disturbance mode of action of the stressor. Biotic indicators based on a priori selected traits represent a promising biomonitoring tool even for regions where ecological information is scarce.
How to characterize chemical exposure to predict ecologic effects on aquatic communities?
Publisher: American Chemical Society (ACS)
Date: 02-07-2013
DOI: 10.1021/ES4014954
Abstract: Reliable characterization of exposure is indispensable for ecological risk assessment of chemicals. To deal with mixtures, several approaches have been developed, but their relevance for predicting ecological effects on communities in the field has not been elucidated. In the present study, we compared nine metrics designed for estimating the total toxicity of mixtures regarding their relationship with an effect metric for stream macroinvertebrates. This was done using monitoring data of biota and organic chemicals, mainly pesticides, from five studies comprising 102 streams in several regions of Europe and South-East Australia. Mixtures of less than 10 pesticides per water s le were most common for concurrent exposure. Exposure metrics based on the 5% fraction of a species sensitivity distribution performed best, closely followed by metrics based on the most sensitive species and Daphnia magna as benchmark. Considering only the compound with the highest toxicity and ignoring mixture toxicity was sufficient to estimate toxicity in predominantly agricultural regions with pesticide exposure. The multisubstance Potentially Affected Fraction (msPAF) that combines concentration and response addition was advantageous in the study where further organic toxicants occurred. We give recommendations on exposure metric selection depending on data availability and the involved compounds.
Validating species sensitivity distributions using salinity tolerance of riverine macroinvertebrates in the southern Murray-Darling Basin (Victoria, Australia)
Publisher: Canadian Science Publishing
Date: 08-2006
DOI: 10.1139/F06-080
Abstract: Species sensitivity distributions (SSDs) are commonly used in risk assessment and in setting water quality guidelines, yet their predictions have not been validated against loss of species with increasing pollutant concentrations in nature. We used a rapid toxicity testing method to determine the acute salinity tolerance (72 h LC 50 values (concentration of salinity lethal to 50% of in iduals)) of 110 macroinvertebrate taxa from the southern Murray–Darling Basin in central Victoria, Australia, and construct an SSD. This SSD was compared with loss of riverine macro invertebrates species from increasing salinity in Victoria. Macroinvertebrate species richness per in idual s le, when salinity was .9 mS·cm –1 , was invariant of salinity. However, when species richness was calculated across multiple s les above about 0.3–0.5 mS·cm –1 , it declined with increasing salinity. This decline was predicted from the SSD after application of a variable safety factor calculated from an exponential or quadratic equation. Our findings confirm that SSDs can predict the loss of freshwater macroinvertebrate species from increases in salinity. This suggests that SSDs may be useful more generally for other aquatic organisms, other stressors, and toxicants.
Growth of the damselfly Ischnura heterosticta is better in saline water than freshwater
Publisher: Elsevier BV
Date: 06-2006
DOI: 10.1016/J.ENVPOL.2005.08.064
Abstract: Increasing salinity has the potential to affect freshwater organisms. Yet sub-lethal effects of salinity on macroinvertebrates are poorly understood. Growth and development of Ischnura heterosticta (Odonata: Coenagrionidae) was experimentally shown to be faster in 5-20 mS/cm than 0.1-1 mS/cm, while in 35 mS/cm all in iduals died. In 30 mS/cm about half died and growth was similar to the 0.1 mS/cm treatment. The salinity-growth relationship cannot be explained indirectly, that is salinity affecting the survival of their prey. Tissue content and concentration of Ca, Mg, Na and K in emerged adults showed no evidence of deficiencies at low salinity. Heart beat rate was similar across treatments, except at 35 mS/cm, where it was slower. Respiration and feeding were similar at 0.1, 10 and 30 mS/cm. While there are similarities in I. heterosticta and other species' salinity response, there are differences and studies on more species are urgently needed.
The influence of reduced light intensity on the response of benthic diatoms to herbicide exposure
Publisher: Wiley
Date: 15-06-2016
DOI: 10.1002/ETC.3379
Abstract: Herbicide pollution events in aquatic ecosystems often coincide 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 4 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 2 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. Environ Toxicol Chem 2016 :2252-2260. © 2016 SETAC.
Interactions in statistical models: Three things to know
Publisher: Wiley
Date: 15-09-2021
Abstract: In ecological studies, the magnitude and direction of interactions among two continuous explanatory variables x 1 and x 2 are commonly evaluated by fitting a statistical model of the form , where x 1 x 2 is an interaction term that measures departure from additivity of effects. Here, we highlight three issues associated with evaluating interactions in statistical models of this form that appear underappreciated in the ecological literature, but which have important implications for how we fit models and correctly identify interactions. First, the scale (additive or multiplicative) on which the outcome variable y is modelled matters. Transformations that change the scale of analysis alter the interpretation of interaction terms and can hide interactions of ecological importance. Second, spurious interactions can arise when explanatory variables are correlated and there are unmodeled nonlinear relationships, a situation likely to arise when fitting statistical models to non‐experimental data. Third, interactions can be nonlinear such that the interaction term x 1 x 2 will not capture all interactions of ecological interest. We illustrate how each of these issues can result in potentially misleading outcomes using ex les linked to the impacts of multiple stressors on bio ersity. We provide recommendations aimed at correctly identifying interaction effects from statistical models.
More on the Liang Bua finds and modern human cretins
Publisher: Elsevier BV
Date: 12-2012
DOI: 10.1016/J.JCHB.2012.09.005
Abstract: Brown (2012: LB1 and LB6 Homo floresiensis are not modern human (Homo sapiens) cretins, Journal of Human Evolution) makes errors of fact, omission and interpretation. Brown's comments refer, among others, to (1) delayed growth and development indicated by unfused epiphyses, (2) postcranial limb proportions: limbs to trunk, between limbs, and within limbs, (3) postcranial bone torsions and angles, (4) postcranial robusticity, real and apparent, (5) skull features, and (6) cretinism on Flores. In each of these areas, much information about cretins is incorrect and much information (Oxnard et al., 2010) comparing the Liang Bua remains with cretins is ignored.
Tackling inconsistencies among freshwater invertebrate trait databases
Publisher: Wiley
Date: 18-11-2022
DOI: 10.1111/FWB.13840
Abstract: Use of invertebrate traits rather than species composition may facilitate large‐scale comparisons of community structure and responses to disturbance in freshwater ecology because the same traits potentially occur everywhere. In recent years, comprehensive invertebrate trait databases have been established at different scales (e.g., regions, continents). The wide availability of invertebrate trait data supports large‐scale studies. However, a number of data‐related issues complicate the use of invertebrate traits for ecological studies. It is uncertain how harmonising varying trait definitions among databases might influence subsequent identification of trait–environment relationships. Furthermore, there have been few comparisons of trait aggregation approaches with expert‐assigned trait affinities. We describe inconsistencies in the definitions of traits used to create freshwater invertebrate trait databases in Europe, North America, New Zealand, and Australia. Based on our comparisons of these databases, we established four novel trait datasets by harmonising definitions of commonly used traits. Next, we used two of these datasets to compare aggregated traits obtained by different aggregation methods with traits assigned by experts, both at the family level. The trait aggregation methods that we compared used either the mean or the median and different weightings. We further explored the effects of harmonisation and trait aggregation by re‐analysing data from a case study. We found that among databases, trait definitions often differed because varying numbers of traits were used to describe particular functions (e.g., respiration traits) and the way those functions were described also varied (e.g., for feeding mode some databases focused on the food source, whereas others focused on mouthpart morphology). The coding to describe traits (binary, fuzzy) also varied among databases. Our comparison of different aggregation methods showed that family‐level aggregated and expert‐assigned traits were similar, especially when traits were aggregated based on the median of trait values of taxa within a family. The case study showed that harmonised and aggregated data identified similar trait–environment relationships to non‐aggregated data. However, harmonised and aggregated data yielded only partially similar values for functional ersity metrics when compared to the case study results. By identifying inconsistencies in trait definitions we hope to motivate the development of standardised definitions for invertebrate traits. Our results also illustrate the usefulness of harmonised datasets for ecological study and provide guidance for the circumstances under which the choice of trait aggregation method is important.
Towards routine DNA metabarcoding of macroinvertebrates using bulk samples for freshwater bioassessment: Effects of debris and storage conditions on the recovery of target taxa
Publisher: Wiley
Date: 19-12-2019
DOI: 10.1111/FWB.13443
The relationship between electrical conductivity and selected macroinvertebrate communities in four river systems of south-west Victoria, Australia
Publisher: Springer Science and Business Media LLC
Date: 1998
Effects of pH on salinity tolerance of selected freshwater invertebrates
Publisher: Springer Science and Business Media LLC
Date: 11-2009
Effects of different ionic compositions on survival and growth of Physa acuta
Publisher: Springer Science and Business Media LLC
Date: 09-10-2009
Effects of pesticide toxicity, salinity and other environmental variables on selected ecosystem functions in streams and the relevance for ecosystem services
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.SCITOTENV.2011.05.063
Abstract: Effects of anthropogenic and environmental stressors on freshwater communities can propagate to ecosystem functions and may in turn impede ecosystem services. We investigated potential shifts in ecosystem functions that provide energy for freshwater ecosystems due to pesticides and salinity in 24 sites in streams of southeast Australia. First, effects on allochthonous organic matter (AOM) breakdown using three different substrates (leaves, cotton strips, wood sticks) in coarse and fine bags were investigated. Second, we examined effects on stream metabolism that delivers information on the ecosystem functions of gross primary production and ecosystem respiration. We found up to a fourfold reduction in AOM breakdown due to exposure to pesticides and salinity, where both stressors contributed approximately equally to the reduction. The effect was additive as, no interaction or correlation between the two stressors was found. Leaf breakdown responded strongly and exclusively to exposure to pesticides and salinity, whereas cotton strip breakdown was less sensitive and responded also to other stressors such as nutrients. No functional redundancy for the effects of pesticides and salinity on leaf breakdown was observed. For wood stick breakdown, no relationship to environmental gradients was found, however, the s le size was lower. We did not detect effects of pesticides or salinity on gross primary production or ecosystem respiration. A reduction in AOM breakdown by pesticides and salinity may impair the ecosystem services of food provision and possibly water purification. Hence, future studies should examine the spatial extent of these effects.
Looking beneath the surface: using hydrogeology and traits to explain flow variability effects on stream macroinvertebrates
Publisher: Wiley
Date: 04-05-2016
DOI: 10.1002/ECO.1741
Effects of Pesticides Monitored with Three Sampling Methods in 24 Sites on Macroinvertebrates and Microorganisms
Publisher: American Chemical Society (ACS)
Date: 19-01-2011
DOI: 10.1021/ES103227Q
Abstract: Grab water s les, sediment s les, and 2,2,4-trimethylpentane passive s lers (TRIMPS) were used to determine the exposure to 97 pesticides in 24 southeast Australian stream sites over 5 months. Macroinvertebrate communities and selected microorganisms (bacteria, flagellates, ciliates, amoebas, nematodes, and gastrotrichs) were s led to detect relationships with pesticide toxicity. Sediment s les had the highest estimated toxicities in terms of toxic units (TU) for Daphnia magna (TUDM) and for Selenastrum capricornutum (TUSC). The pesticide-selective SPEARpesticides and the general SIGNAL index for macroinvertebrates exhibited negative linear relationships (r(2) = 0.67 and 0.36, respectively) with pesticide contamination in terms of log maximum TUDM (log mTUDM), suggesting macroinvertebrate community change due to pesticide exposure. Pesticide contamination was the only measured variable explaining variation in ecological quality. Variation in the densities of several microbial groups was best explained by environmental variables other than log TUs. The log mTUDM values derived from sediment concentrations were most important to establish a link with effects on macroinvertebrates, whereas log mTUDM of grab water s les had only minor contribution. Current-use insecticides and fungicides can affect macroinvertebrate communities and monitoring of sediment and continuous water s ling is needed to detect these effects.
The salinity tolerance of freshwater macroinvertebrate eggs and hatchlings in comparison to their older life-stages: a diversity of responses - The salinity tolerance of freshwater macroinvertebrate eggs and hatchlings
Publisher: Springer Science and Business Media LLC
Date: 14-11-2007
Similar recovery time of microbial functions from fungicide stress across biogeographical regions
Publisher: Springer Science and Business Media LLC
Date: 19-11-2018
DOI: 10.1038/S41598-018-35397-1
Abstract: Determining whether the structural and functional stress responses of communities are similar across space and time is paramount for forecasting and extrapolating the consequences of anthropogenic pressures on ecosystems and their services. Stream ecosystems are under high anthropogenic pressure however, studies have only examined the response of stream communities across large scales over multiple generations. We studied the responses of leaf-associated microbial communities in streams within three European biogeographical regions to chemical stress in a microcosm experiment with multiple cycles of fungicide pollution and resource colonisation. Fungal community composition and the ecosystem function leaf decomposition were measured as response variables. Microbial leaf decomposition showed similar recovery times under environmental levels of fungicide exposure across regions. Initially, the decomposition declined (between 19 and 53%) under fungicide stress and recovered to control levels during the third cycle of pollution and colonisation. Although community composition and its stress response varied between regions, this suggests similar functional community adaptation towards fungicide stress over time. Genetic, epigenetic and physiological adaptations, as well as species turnover, may have contributed to community adaptation but further studies are required to determine if and to which extent these mechanisms are operating. Overall, our findings provide the first evidence of a similar functional response of microbial leaf decomposition to chemical stress across space and time.
Relative salinity tolerance of freshwater macroinvertebrates from the south-east Eastern Cape, South Africa compared with the Barwon Catchment, Victoria, Australia
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/MF04098
Abstract: Salinity is rising in many southern African and Australian rivers with unknown effects on aquatic organisms. The extent of spatial variation, at any scale, in salt tolerances of aquatic organisms is unknown, so whether data from one location is applicable elsewhere is also unknown. The acute tolerances (72-h median lethal concentration (LC50)) to sea salt of 49 macroinvertebrate taxa from the south-east Eastern Cape (SEEC), South Africa were compared with those of 57 species from the Barwon Catchment, Victoria, Australia. The mean LC50 values from both locations were similar (Barwon: 31 and SEEC: 32 mS cm−1) and less abundant (rare) taxa tended to be more tolerant than more abundant (common) taxa. There was, however, a greater range of LC50 values (5.5–76 mS cm−1) in the Barwon Catchment than in the SEEC (11–47 mS cm−1). The species sensitivity distribution (SSD) for SEEC taxa was bimodal whereas the Barwon Catchment’s SSD had a single peak. With few exceptions, members of an order had similar tolerances in both locations. The differences in SSD between locations were related to crustacean, odonate and non-arthropod relative richness. Although it is not ideal to extrapolate SSDs from one location to another, it may be reasonable to assume similar salinity tolerances among related taxa.
Is all salinity the same? I. The effect of ionic compositions on the salinity tolerance of five species of freshwater invertebrates
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/MF05103
Abstract: Salts of marine origin, predominantly consisting of Na+ and Cl− ions, are dominant in most Australian inland saline waters. The proportions of other ions, Ca2+, Mg2+, SO42–, HCO3− and CO32–, in the water may influence salinity tolerance of freshwater organisms and thus the effect of increasing salinity may vary with difference in ionic proportions. We exposed freshwater invertebrates to different concentrations of four ionic compositions and compared them with commercial sea salt (Ocean Nature). They were: synthetic Ocean Nature (ONS) and three saline water types (ONS but without: SO42–, HCO3− and CO32– (S1) Ca2+, HCO3− and CO32– (S2) and Ca2+ and Mg2+ (S3)), which are considered to be the predominant saline water types in south-eastern Australia and the Western Australian wheatbelt. The 96-h LC50 values for the five media were determined for six invertebrate species and sub-lethal responses were observed for two species. There were no differences between responses of invertebrates to various ionic compositions in acute toxicity tests. However, in prolonged sub-lethal tests, animals reacted differently to the various ionic compositions. The greatest effect was observed in water types lacking Ca, for which plausible physiological mechanisms exist. Variation in ionic proportions should be taken into account when considering sub-lethal effects of salinity on freshwater invertebrates.
Sensitivity and specificity of macroinvertebrate responses to gradients of multiple agricultural stressors
Publisher: Elsevier BV
Date: 12-2021
The definition of species richness used by species sensitivity distributions approximates observed effects of salinity on stream macroinvertebrates
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.ENVPOL.2010.08.025
Abstract: The risk of chemicals for ecological communities is often forecast with species sensitivity distributions (SSDs) which are used to predict the concentration which will protect p% of species (PCp value). However, at the PCp value, species richness in nature would not necessary be p% less than at uncontaminated sites. The definition of species richness inherent to SSDs (contaminant category richness) contrasts with species richness typically measured in most field studies (point richness). We determine, for salinity in eastern Australia, whether these definitions of stream macroinvertebrate species richness are commensurable. There were strong relationships (r2≥0.87) between mean point species, family and Ephemeroptera, Trichoptera and Plecoptera species richness and their respective contamination category richness. Despite differences in the definition of richness used by SSDs and field biomonitoring, their results in terms of relative species loss from salinity in south-east Australia are similar. We conclude that in our system both definitions are commensurable.
Is salinity the only water quality parameter affected when saline water is disposed in rivers?
Publisher: Springer Science and Business Media LLC
Date: 1998
Are salinity tolerances of non-native macroinvertebrates in France an indicator of potential for their translocation in a new area?
Publisher: Elsevier BV
Date: 05-2011
Exploring the interplay of biotic interactions and salinity stress in freshwater invertebrate assemblages
Publisher: CSIRO Publishing
Date: 07-04-2022
DOI: 10.1071/MF22043
Abstract: The most parsimonious interpretation of our experimental findings (Bray 2019 Kefford 2022) is that the effect of experimental increases in salinity on stream macroinvertebrate communities, was altered by organisms from a high-salinity site. This interpretation is consistent with long-established and widely accepted ecological and ecotoxicological theory. The suggestion (Chessman 2022) that the initial community was confounded, that it converged within the first week of the experiment and then erged again, is neither parsimonious nor explicable by theory. All experiments are imperfect, yet we maintain that our experiment is informative, and we encourage other researchers to generate new data to inform on the degree to which abiotic and biotic effects of salinity, and other abiotic stressors, affect ecological communities.
Size of anal papillae in chironomids: Does it indicate their salinity stress?
Publisher: Elsevier BV
Date: 05-2011
Using silicone passive samplers to detect polycyclic aromatic hydrocarbons from wildfires in streams and potential acute effects for invertebrate communities
Publisher: Elsevier BV
Date: 08-2010
DOI: 10.1016/J.WATRES.2010.05.044
Abstract: Silicone rubber passive s lers spiked with 4 deuterated performance reference compounds were deployed for 29-33 days to estimate the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in 9 streams in Victoria, Australia, following a wildfire. Silicone rubber strips of 2 thicknesses were used to obtain information on the status of uptake of the chemicals of interest at retrieval. In addition, we monitored the stream macroinvertebrate community for potential effects of PAHs or other fire organics. All selected PAHs were detected in the passive s lers and the s ling rates ranged from 0.5 to 50 L/day significantly varying between sites but not compounds, presumably due to differences in current velocity. The estimated water concentrations were 0.1-10 ng/L for total PAHs with phenanthrene, pyrene and fluoranthene accounting for 91% of the total concentration. All PAHs were a factor of 1000 or more below the reported 48-h median lethal concentrations (48-h LC50) for Daphnia magna. Two sites located closest to the fires exhibited elevated concentrations compared to the other sites and the passive s lers in these sites remained in the integrative uptake regime for all compounds, suggesting precipitation-associated PAH input. No acute toxic effects of PAHs or other fire organics on the invertebrate community were detected using a biotic index for organic toxicants (SPEAR), whereas a non-specific biotic index (SIGNAL) decreased in two sites indicating impacts from changes in other environmental parameters. We conclude (1) that silicone-based passive s lers with two different area-to-volume ratios represent a promising tool for determining organic toxicants and (2) that PAHs from wildfires are unlikely to be a common main cause for fire-related ecological effects in streams adjacent to burnt regions.
Taxonomic Distinctness as a Measure of Diversity of Stream Insects Exposed to Varying Salinity Levels in South-Eastern Australia
Publisher: Wiley
Date: 17-02-2012
Are the small human-like fossils found on Flores human endemic cretins?
Publisher: The Royal Society
Date: 04-03-2008
Abstract: Fossils from Liang Bua (LB) on Flores, Indonesia, including a nearly complete skeleton (LB1) dated to 18 kyr BP, were assigned to a new species, Homo floresiensis . We hypothesize that these in iduals are myxoedematous endemic (ME) cretins, part of an inland population of (mostly unaffected) Homo sapiens . ME cretins are born without a functioning thyroid their congenital hypothyroidism leads to severe dwarfism and reduced brain size, but less severe mental retardation and motor disability than neurological endemic cretins. We show that the fossils display many signs of congenital hypothyroidism, including enlarged pituitary fossa, and that distinctive primitive features of LB1 such as the double rooted lower premolar and the primitive wrist morphology are consistent with the hypothesis. We find that the null hypothesis (that LB1 is not a cretin) is rejected by the pituitary fossa size of LB1, and by multivariate analyses of cranial measures. We show that critical environmental factors were potentially present on Flores, how remains of cretins but not of unaffected in iduals could be preserved in caves, and that extant oral traditions may provide a record of cretinism.
A single measure of salinity: Is this representative of a river's past salinity?
Publisher: Informa UK Limited
Date: 03-2001
No evidence for a critical salinity threshold for growth and reproduction in the freshwater snail Physa acuta
Publisher: Elsevier BV
Date: 04-2005
DOI: 10.1016/J.ENVPOL.2004.09.018
Abstract: The growth and reproduction of the freshwater snail Physa acuta (Gastropoda: Physidae) were measured at various salinity levels (growth: distilled water, 50, 100, 500, 1000 and 5000 microS/cm reproduction: deionized water, 100, 500, 1000 and 3000 microS/cm) established using the artificial sea salt, Ocean Nature. This was done to examine the assumption that there is no direct effect of salinity on freshwater animals until a threshold, beyond which sub-lethal effects, such as reduction in growth and reproduction, will occur. Growth of P. acuta was maximal in terms of live and dry mass at salinity levels 500-1000 microS/cm. The number of eggs produced per snail per day was maximal between 100 and 1000 microS/cm. Results show that rather than a threshold response to salinity, small rises in salinity (from low levels) can produce increased growth and reproduction until a maximum is reached. Beyond this salinity, further increases result in a decrease in growth and reproduction. Studies on the growth of freshwater invertebrates and fish have generally shown a similar lack of a threshold response. The implications for assessing the effects of salinisation on freshwater organisms need to be further considered.
How are macroinvertebrates of slow flowing lotic systems directly affected by suspended and deposited sediments?
Publisher: Elsevier BV
Date: 02-2010
DOI: 10.1016/J.ENVPOL.2009.08.008
Abstract: The effects of suspended and deposited sediments on the macroinvertebrates are well documented in upland streams but not in slower flowing lowland rivers. Using species found in lowland lotic environments, we experimentally evaluate mechanisms for sediments to affect macroinvertebrates, and in one experiment whether salinity alters the effect of suspended sediments. Suspended kaolin clay reduced feeding of Ischnura heterosticta (Odonata: Coenagrionidae) at high turbidity (1000-1500 NTU) but had no effects on feeding of Hemianax papuensis (Odonata: Aeshnidae) and Micronecta australiensis (Hemiptera: Corixidae). In freshwater (0.1 mS/cm), survival of Ischnura aurora was poor in clear water, but improved with suspended kaolin. Growth and feeding of I. aurora were unaffected by suspended sediments and salinity. Burial (1-5 mm) of eggs with kaolin or sand reduced hatching in Physa acuta (Gastropoda: Physidae), Gyraulus tasmanica (Gastropoda: Planorbidae) and Chironomus cloacalis (Diptera: Chironomidae). Settling sediments may pose greater risk to lowland lotic invertebrates than suspended sediments.
Bicarbonate toxicity to Ceriodaphnia dubia and the freshwater shrimp Paratya australiensis and its influence on zinc toxicity
Publisher: Wiley
Date: 27-03-2014
DOI: 10.1002/ETC.2545
Abstract: Bicarbonate is often a major ionic constituent associated with produced waters from methane gas extraction and coal mining, yet few studies have determined its specific toxicity. Currently, the environmental risk of bicarbonate anion in water discharges is assessed based on the toxicity of sodium chloride or artificial seawater and is regulated via electrical conductivity. Increased NaHCO(3) added to Ceriodaphnia dubia in synthetic or natural water gave similar 48-h 10% effective concentration (EC10) values of 1750 ± 125 mg NaHCO(3)/L (mean ± standard error) and 1670 ± 180 mg NaHCO(3)/L, respectively. Bicarbonate was toxic to C. dubia in both waters with conductivities above 1900 µS/cm. In contrast, when conductivity was elevated with NaCl, toxicity to C. dubia was observed only above 2800 µS/cm. Bicarbonate also impaired C. dubia reproduction with an EC10 of 340 mg NaHCO(3)/L. Major ion composition also influenced Zn bioavailability, a common co-occurring metal contaminant in coal mine waters, with sublethal concentrations of NaHCO(3) and elevated pH increasing Zn toxicity. Higher pH was the dominant parameter determining a 10-fold increase in the 48-h 50% effective concentration (EC50) for Zn toxicity to C. dubia at pH 8.6 of 34 µg Zn/L (95% confidence limit = 32-37 µg Zn/L) compared with the Zn toxicity at approximately circumneutral pH. Exposure of the freshwater shrimp Paratya australiensis (Atyidae) in natural water to increasing bicarbonate gave a mean 10-d 10% lethal concentration (LC10) of 850 ± 115 mg NaHCO(3)/L, associated with a mean conductivity EC10 of 1145 µS/cm, which is considerably lower than toxicity of NaCl and artificial seawater to this species reported elsewhere. Because toxicity was influenced by salt composition, specific ions should be regulated rather than conductivity alone in mine wastewater discharges.
Corrigendum to “Sensitivity and specificity of macroinvertebrate responses to gradients of multiple agricultural stressors” [Environ. Pollut. 291 (December 2021) 118092]
Publisher: Elsevier BV
Date: 2022
Assessing the Relative Toxicity of Different Road Salts and Effect of Temperature on Salinity Toxicity: LCx Values versus No-Effect Concentration (NEC) Values
Publisher: Springer Science and Business Media LLC
Date: 29-01-2022
DOI: 10.1007/S00244-021-00908-1
Abstract: Freshwater biota are at risk globally from increasing salinity, including increases from deicing salts in cold regions. A variety of metrics of toxicity are used when estimating the toxicity of substances and comparing the toxicity between substances. However, the implications of using different metrics are not widely appreciated. Using the mayfly Colobruscoides giganteus (Ephemeroptera: Colobruscoidea), we compare the toxicity of seven different salts where toxicity was estimated using two metrics: (1) the no-effect concentrations (NEC) and (2) the lethal concentrations for 10, 25 and 50% of the test populations (LC
The mayfly nymph Austrophlebioides pusillus harker defies common osmoregulatory assumptions
Publisher: The Royal Society
Date: 2017
DOI: 10.1098/RSOS.160520
Abstract: Osmoregulation is a key physiological function, critical for homeostasis. The basic physiological mechanisms of osmoregulation are thought to be well established. However, through a series of experiments exposing the freshwater mayfly nymph Austrophlebioides pusillus (Ephemeroptera) to increasing salinities, we present research that challenges the extent of current understanding of the relationship between osmoregulation and mortality. A. pusillus had modelled 96 h LC 10 , LC 50 and LC 99 of 2.4, 4.8 and 10 g l −1 added synthetic marine salt (SMS), respectively. They were strong osmoregulators. At aquarium water osmolality of 256 ± 3.12 mmol kg −1 (±s.e. equivalent to 10 g l −1 added SMS), the haemolymph osmolality of A. pusillus was a much higher 401 ± 4.18 mmol kg −1 (±s.e.). The osmoregulatory capacity of A. pusillus did not break down, even at the salinity corresponding to their LC 99 , thus their mortality at this concentration is due to factors other than increased internal osmotic pressure. No freshwater invertebrate has been previously reported as suffering mortality from rises in salinity that are well below the iso-osmotic point. Recently, studies have reported reduced abundance/richness of Ephemeroptera with slightly elevated salinity. Given that salinization is an increasing global threat to freshwaters, there is an urgent need for studies into the osmophysiology of the Ephemeroptera to determine if their loss at locations with slightly elevated salinity is a direct result of external salinity or other, possibly physiological, causes.
Determining the relative sensitivity of benthic diatoms to atrazine using rapid toxicity testing: A novel method
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.SCITOTENV.2014.03.115
Abstract: Herbicides pose a potential threat to aquatic ecosystems, especially to phototrophic organisms such as benthic diatoms. Benthic diatoms may be a valuable indicator of the toxic impacts of herbicides in aquatic systems. However, this requires information on the herbicide sensitivity of a wide range of freshwater benthic diatom taxa. Unfortunately this information is only available for a limited number of species as current methods of developing new algae toxicity tests on in idual taxa are lengthy and costly. To address this issue, we developed a new rapid toxicity test method to test natural benthic communities, from which the relative herbicide sensitivity of many in idual taxa can be derived. This involved the collection of natural benthic communities from rocks in situ, which were placed directly into laboratory toxicity tests. Sensitivity data for several diatom genera in a 48 hour exposure toxicity test were produced, without the need for cultures or multiple site visits. After exposure to the highest treatment of atrazine (500 μg L(-1)) there were significant declines of healthy cells in the most sensitive genera: Gomphonema declined by 74%, Amphora by 62%, Cymbella by 54% and Ulnaria by 34% compared to control levels. In contrast, the genera, Eunotia, Achnanthidium and Navicula, had no statistically significant decline in cell health. This method can identify the diatom taxa most at risk of herbicide toxicity within the natural benthic diatom community. The rapid toxicity testing method presented is a simple and effective method to obtain sensitivity data for multiple taxa within a natural benthic diatom community in a relatively short period of time.
Leaf litter breakdown along an elevational gradient in Australian alpine streams
Publisher: Wiley
Date: 10-2022
DOI: 10.1002/ECE3.9433
Abstract: The breakdown of allochthonous organic matter, is a central step in nutrient cycling in stream ecosystems. There is concern that increased temperatures from climate change will alter the breakdown rate of organic matter, with important consequences for the ecosystem functioning of alpine streams. This study investigated the rate of leaf litter breakdown and how temperature and other factors such as microbial and invertebrate activities influenced this over elevational and temporal gradients. Dried leaves of Snow Gum ( Eucalyptus pauciflora ) and cotton strips were deployed in coarse (6 mm), and fine (50 μm) mesh size bags along an 820 m elevation gradient. Loss of mass in leaf litter and cotton tensile strength per day ( k per day), fungal biomass measured as ergosterol concentration, invertebrate colonization of leaf litter, and benthic organic matter (mass and composition) were determined. Both microbial and macroinvertebrate activities were equally important in leaf litter breakdown with the abundance of shredder invertebrate taxa. The overall leaf litter breakdown rate and loss of tensile strength in cotton strips (both k per day) were greater during warmer deployment periods and at lower elevations, with significant positive relationships between mean water temperature and leaf breakdown and loss of tensile strength rate, but no differences between sites, after accounting for the effects of temperature. Despite considerably lower amounts of benthic organic matter in streams above the tree line relative to those below, shredders were present in coarse mesh bags at all sites. Ergosterol concentration was greater on leaves in coarse mesh bags than in fine mesh bags, implying differences in the microbial communities. The importance of water temperatures on the rate of leaf litter breakdown suggests the potential effects of climate change‐induced temperature increases on ecological processes in such streams.
The effect of saline water disposal: Implications for monitoring programs and management
Publisher: Springer Science and Business Media LLC
Date: 2000
Sub-lethal and chronic salinity tolerances of three freshwater insects: Cloeon sp and Centroptilum sp (Ephemeroptera : Baetidae) and Chironomus sp (Diptera : Chironomidae)
Publisher: The Company of Biologists
Date: 15-10-2006
DOI: 10.1242/JEB.02457
Abstract: Increased salinity in rivers and streams is a serious environmental concern, and in Australia there is growing information about the acute tolerances to salinity for freshwater macroinvertebrates, but much less information about chronic and sub-lethal tolerances. The effects of increased salinity on the growth and survival of two mayflies, Cloeon sp. and Centroptilum sp. and one midge Chironomus sp. are reported. In both mayfly species survival was variable. Complete mortality was observed in salinities with electrical conductivity of 10 mS cm–1 and higher. Salinities causing chronic mortality in mayflies were measured as 21-day LC50, and ranged from 0.90 to 2.7 mS cm–1. Growth rates were not significantly different between treatments. In Chironomus, salinity affected the mean number emerging as flying adults as well as the time to emergence. An inverted `U' shape response was observed for percentage emergence, with the greatest numbers emerging at intermediate salinities (0.65–5.0 mS cm–1). No emergence occurred at salinities of 20 mS cm–1 and higher. Time to emergence was delayed by 15–88% with increased salinity, however the size of emerged adults was the same for all treatments. Growth rates were reduced with increased salinity, showing a slow, steady reduction up to 10 mS cm–1 then a steep decline between 10 and 15 mS cm–1. The implications of altered growth rates and changes in developmental times are discussed. This study illustrates the variability in responses to increased salinity, and highlights the need to continue studying sub-lethal and chronic exposures in a range of freshwater invertebrates, in order to predict impacts of salinisation on freshwater bio ersity.
Effect of spatial variation on salinity tolerance of macroinvertebrates in Eastern Australia and implications for ecosystem protection trigger values
Publisher: Elsevier BV
Date: 02-2008
DOI: 10.1016/J.ENVPOL.2007.03.020
Abstract: Salinisation of freshwater has been identified as a serious environmental issue in Australia and around the world. Protective concentrations (trigger values) for salinity can be used to manage salinity impacts, though require locally relevant salinity tolerance information. 72-h acute salinity tolerance values were determined for 102 macroinvertebrates collected from 11 locations in four biologically distinct freshwater bio-regions in Northeast Australia and compared with sensitivities observed in Southeast Australia. The salinity tolerance of in idual taxa was consistent across Northeast Australia and between Northeast and Southeast Australia. However, two distinct communities were identified in Northeast Australia using distributions of the acute tolerance values and a calculated index of salinity sensitivity. Salinity trigger values should therefore be representative of local or regionally relevant communities and may be adequately calculated using sensitivity values from throughout Eastern Australia. The results presented provide a basis for assessing salinity risk and determining trigger values for salinity in freshwater ecosystems at local and regional scales in Eastern Australia.
Sub-organism (acetylcholinesterase activity), population (survival) and chemical concentration responses reinforce mechanisms of antagonism associated with malathion toxicity
Publisher: Elsevier BV
Date: 07-2021
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