Adopting and adapting macroinvertebrate measures for health assessments of ephemeral freshwater systems a review /

Ephemeral streams are waterways with poorly defined channels and episodic flow. Globally, the occurrence of ephemeral streams appears to be increasing due to drying trends driven by climate change, as well as a result of increased water abstraction. Simultaneously, these pressures result in increased vulnerability of ephemeral streams, as flow rates decline from intermittent to entirely absent. Despite this, ephemeral waterways are broadly neglected by ecologists, and no tailored measures are available to study the health of these systems. Traditional assessment methods applied to lotic or lentic environments include physicochemical analyses, often paired with the use of biological indicators. Due to abundance and diversity, sensitivity to changes in flow, water quality and toxicity aquatic macroinvertebrates are widely used as indicators of ecological condition. However, the theoretical base underpinning the use of macroinvertebrate protocols to assess waterway condition has generally been developed from studies of temperate, permanent waterways with few studies specific to tropical or subtropical ephemeral environments. To address the knowledge gap, this review examines the current state of knowledge regarding the health of ephemeral systems, focussing on Australian freshwaters. It also examines the applicable ecosystem health measures that may be transferable to ephemeral systems, with a focus on macroinvertbrates as bioindicator species

Macroinvertebrate community succession under variable flow regimes in subtropical Australia

Seasonal changes in hydrology are important factors influencing abiotic conditions and subsequently the biota. Although these effects have been studied in tropical catchments and in central arid Australia, subtropical ephemeral streams have largely been ignored. In the present study, three ephemeral streams in Central Queensland were monitored over 15 months. We hypothesised that macroinvertebrate abundance would increase gradually following the initial flow pulse and that abundance would increase until the pools began drying, with sensitive taxa only present during higher flow. In all, 69 families from 14 orders were collected in 128 samples. Significant relationships were not detected between low flow conditions and taxa richness (P > 0.05). Principal component analysis showed that the macroinvertebrate communities did not change in response to the drying of pools. Significant differences were not observed between taxa richness, abundance nor tolerant taxa during varied periods of flow (P > 0.05). Sensitive taxa were most abundant during high-flow periods with comparatively less abundance during no flow and drying periods. This study provides novel information on the flow-linked succession of macroinvertebrate communities in subtropical ephemeral streams and the results are important in informing the development of riverine indices and models used to manage subtropical environments

A role for aeration and intake depth in managing toxic Cylindrospermopsis : a comparison between off-stream and riverine environments in the Fitzroy Basin, Australia

Cylindrospermopsis is a cyanobacterial species of global concern, due to its ability to produce potent toxins and its near cosmopolitan distribution. To date, both management and research efforts for Cylindrospermopsis have focused on riverine settings. By contrast, off-stream storages are inadequately studied, particularly in terms of population dynamics and toxin profiles, how these are linked with the riverine systems that seed them, and what management options are best for optimizing water quality. This is a critical gap, given that storages are key off-take points for many water users, including for livestock watering and industrial supply. This study examined the relationship between a riverine and an off-stream environment, with respect to the development of toxic Cylindrospermopsis blooms in central Queensland. It discusses the role of an aeration system in preventing or delaying bloom development and explores the implications of intake depth with respect to population (cell density) and toxicity. Along the impounded river, the study sites featured warm, stratified conditions and an anoxic hypolimnion. By contrast, the off-stream storage dam lacked stratification, due to the constant aeration provided by a hypolimnetic bubbler. Cylindrospermopsis raciborskii blooms appeared in both environments, with peak cellular concentrations detected in the subsurface waters. The dynamics of the toxin profiles differed, however, with the riverine concentrations being mostly epilimnetic, whereas the dam featured toxin distributed throughout the water column. Concentrations of both cylindrospermopsin (CYN) and deoxy-cylindrospermopsin (deoxy-CYN) were lower in the dam, compared with the riverine sites. A one-month lag period was evident before C. raciborskii cells appeared in the dam following their observation in the river samples, and a similar period elapsed before the dam populations reached their peak concentrations. These data are invaluable in considering the best management options for off-stream sites that experience seeding from riverine populations, particularly for toxin producers such as Cylindrospermopsis

Response of macroinvertebrate communities to seasonal hydrologic changes in three sub-tropical Australian streams

© 2017, Springer International Publishing Switzerland. In the Australian sub-tropics, seasonal changes in hydrology can influence abiotic conditions, and consequently, the biota. Several methods of macroinvertebrate analyses, including the use of taxonomic groupings, are used to ascertain information regarding stream biodiversity and health. The use of biological traits to group and analyse macroinvertebrate communities, however, may provide a better picture of stream health, particularly in ephemeral streams. To address whether this is the case, three ephemeral systems in the lower Fitzroy catchment, Central Queensland, Australia, were studied over an 18-month period. A total of 69 macroinvertebrate families from 14 orders were collected in 128 samples. Taxonomic analysis indicated there was a range of habitat preferences within groups characterized by a large proportion of tolerant and generalist taxa. The macroinvertebrate communities were categorised into biological trait groups, with a number of predator families found during all flow regimes. A general pattern of Gatherer > Predator > Grazer > Shredder > Filterer was observed. This study provides a clear pattern of the biological traits present during variable flow and could be used as a framework for future stream health modelling. A trait-specific management tool for assessing freshwaters has not yet been adopted in global management protocols and would require both a more definitive understanding of patterns during different flow periods and an internationally recognised set of trait nomenclature

Macroinvertebrate tolerance across a range of conductivities in the Isaac River catchment (Central Queensland)

Sensitive and tolerant species of macroinvertebrate were present at wide range of conductivity concentrations in the Isaac River Catchment in Central Queensland; indicating the need for further ecological studies in the field to underpin the development of regionally-tailored guidelines for conductivity levels. The Isaac Catchment has naturally high levels of conductivity, but there is also increasing pressure to ameliorate saline mine water discharge. Recently, catchment management efforts have included a revision of the broader Fitzroy-specific water quality guidelines. These include the use of macroinvertebrates as indicators of ecosystem health. Studies of macroinvertebrate tolerance to conductivity in southern freshwaters, as well as in laboratory-based ecotoxicological tests conducted in Queensland, suggest that ranges exceeding 1000 µS/cm are likely to have negative impacts on survivorship of all taxa. However, these results may not be transferable to natural populations of macroinvertebrates from the Isaac, where the naturally high-conductivity water may allow the opportunity for adaptation. To test this, macroinvertebrate assemblages were examined at a series of sites in the upper Isaac River catchment at the end of the dry season in 2012. Patterns in the assemblages were examined together with water quality parameters, in order to gauge the ability of macroinvertebrates to survive at conductivity concentrations exceeding 1,000 µS/cm. The specific conductance of the field sites ranged from 477 µS/cm to 9791 µS/cm and a total of 39 Families from 13 Orders were identified. Species richness was not significantly different between sites of differing conductivity. Macroinvertebrate populations were dominated by Dipterans as well as the traditionally more pollution-sensitive families Ephemeroptera and Trichoptera. There was an absence of any correlation between conductivity and species richness (P > 0.050), suggesting that macroinvertebrate taxa richness occurs independently of conductivity, in this cohort of mining and/or grazing influenced ephemeral systems in Central Queensland

Adopting and adapting macroinvertebrate measures for health assessments of ephemeral freshwater systems : a review

Ephemeral streams are waterways with poorly defined channels and episodic flow. Globally, the occurrence of ephemeral streams appears to be increasing due to drying trends driven by climate change, as well as a result of increased water abstraction. Simultaneously, these pressures result in increased vulnerability of ephemeral streams, as flow rates decline from intermittent to entirely absent. Despite this, ephemeral waterways are broadly neglected by ecologists, and no tailored measures are available to study the health of these systems. Traditional assessment methods applied to lotic or lentic environments include physicochemical analyses, often paired with the use of biological indicators. Due to abundance and diversity, sensitivity to changes in flow, water quality and toxicity aquatic macroinvertebrates are widely used as indicators of ecological condition. However, the theoretical base underpinning the use of macroinvertebrate protocols to assess waterway condition has generally been developed from studies of temperate, permanent waterways with few studies specific to tropical or subtropical ephemeral environments. To address the knowledge gap, this review examines the current state of knowledge regarding the health of ephemeral systems, focussing on Australian freshwaters. It also examines the applicable ecosystem health measures that may be transferable to ephemeral systems, with a focus on macroinvertbrates as bioindicator species

A role for aeration and intake depth in managing toxic Cylindrospermopsis a comparison between off-stream and riverine environments in the Fitzroy Basin, Australia /

Cylindrospermopsis is a cyanobacterial species of global concern, due to its ability to produce potent toxins and its near cosmopolitan distribution. To date, both management and research efforts for Cylindrospermopsis have focused on riverine settings. By contrast, off-stream storages are inadequately studied, particularly in terms of population dynamics and toxin profiles, how these are linked with the riverine systems that seed them, and what management options are best for optimizing water quality. This is a critical gap, given that storages are key off-take points for many water users, including for livestock watering and industrial supply. This study examined the relationship between a riverine and an off-stream environment, with respect to the development of toxic Cylindrospermopsis blooms in central Queensland. It discusses the role of an aeration system in preventing or delaying bloom development and explores the implications of intake depth with respect to population (cell density) and toxicity. Along the impounded river, the study sites featured warm, stratified conditions and an anoxic hypolimnion. By contrast, the off-stream storage dam lacked stratification, due to the constant aeration provided by a hypolimnetic bubbler. Cylindrospermopsis raciborskii blooms appeared in both environments, with peak cellular concentrations detected in the subsurface waters. The dynamics of the toxin profiles differed, however, with the riverine concentrations being mostly epilimnetic, whereas the dam featured toxin distributed throughout the water column. Concentrations of both cylindrospermopsin (CYN) and deoxy-cylindrospermopsin (deoxy-CYN) were lower in the dam, compared with the riverine sites. A one-month lag period was evident before C. raciborskii cells appeared in the dam following their observation in the river samples, and a similar period elapsed before the dam populations reached their peak concentrations. These data are invaluable in considering the best management options for off-stream sites that experience seeding from riverine populations, particularly for toxin producers such as Cylindrospermopsis

Spatial variation in the amino acid profile of four macroinvertebrate taxa along a highly polluted river

Acid mine drainage (AMD) is one of the major environmental problems impacting aquatic ecosystems globally. We studied changes in the community composition of macroinvertebrates and amino acid (AA) profiles of dominant taxa along an AMD contamination gradient within the Dee River, Queensland, Australia to understand how AMD can affect the biomolecular composition of macroinvertebrates. Taxa richness and community composition of macroinvertebrates changed widely along the AMD gradient with significantly lower taxa richness recorded at the polluted sites compared to upstream and downstream sites. The Dipteran families: Chironomidae and Ceratopogonidae, the Odonata family Gomphidae, and the Coleoptera family Dytiscidae were the only families found at all sampling sites and were used here for AA analysis. There were significant variations in the AA profiles among the studied taxa. The AA profile of each taxon also varied among upstream, polluted and downstream sites suggesting that contamination of a river system with acid mine drainage not only alters the overall macroinvertebrate community composition but also significantly influences the AA profile of organisms that are tolerant to AMD. This study highlights the potential of using AA profiling to study the response of aquatic organisms to contamination gradients such as those associated with AMD

Validating the Queensland Adult Deterioration Detection System (Q-ADDS): Summary of findings

The overarching aim of this study was to examine the effectiveness of the Q-ADDS to detect adult clinical deterioration within Queensland Hospital and Health Services and to identify the socio-cultural factors influencing health professional compliance with the use of Q-ADDS. To achieve this, we employed a mixed methods approach that included a retrospective chart review, a quantitative survey (closed and open-ended responses) and a qualitative component using interviews