Responses of diatoms and aquatic macroinvertebrates to deposited fine sediment in mesocosm channels as a basis for a new water quality guideline.

Water quality guidelines are an important tool for managing environmental pressures on freshwater streams. Currently, there is a lack of guideline values for fine sediment deposition in South Australian and, more broadly, Australian and overseas streams despite the potentially profound impacts of sediment deposition on aquatic communities. We used an outdoor recirculating stream mesocosm to assess the responses of freshwater diatoms and macroinvertebrates to fine sediment burial after six weeks following a pulsed event.

Comparison of two commonly used methods for identifying water quality thresholds in freshwater ecosystems using field and synthetic data.

Defining ecological thresholds has become increasingly relevant for water resource management. Despite the fact that there has been a rapid expansion in methods to evaluate ecological threshold responses to environmental stressors, evaluation of the relative benefits of various methods has received less attention. This study compares the performance of Gradient Forest (GF) and Threshold Indicator Taxa Analysis (TITAN) for identifying water quality thresholds in both field and synthetic data.

A hydrocarbon-contaminated aquifer reveals a Piggyback-the-Persistent viral strategy.

Subsurface environments hold the largest reservoir of microbes in the biosphere. They play essential roles in transforming nutrients, degrading contaminants and recycling organic matter. Here, we propose a previously unrecognised fundamental microbial process that influences aquifer bioremediation dynamics and that applies to all microbial communities.

Southern South Australian groundwater microbe diversity.

Groundwater is increasingly used globally for domestic, industrial and agricultural production. While many studies have focused on groundwater as a resource, the diverse ecosystems within are often ignored. Here, we assess 54 Southern South Australian groundwater microbial communities from the populated part of the state to assess their status and dynamics in isolated groundwater systems.

Temporal Patterns and Environmental Correlates of Macroinvertebrate Communities in Temporary Streams.

Temporary streams are characterised by short periods of seasonal or annual stream flow after which streams contract into waterholes or pools of varying hydrological connectivity and permanence. Although these streams are widespread globally, temporal variability of their ecology is understudied, and understanding the processes that structure community composition in these systems is vital for predicting and managing the consequences of anthropogenic impacts. We used multivariate and univariate approaches to investigate temporal variability in macroinvertebrate compositional data from 13 years of sampling across multiple sites from autumn and spring, in South Australia, the driest state in the driest inhabited continent in the world.

The Evolution of Epigean and Stygobitic Species of Koonunga Sayce, 1907 (Syncarida: Anaspidacea) in Southern Australia, with the Description of Three New Species.

Three new species of Koonunga were discovered in surface and subterranean waters in southern Australia, and were defined using mtDNA analyses and morphology. The new species are: Koonunga hornei Leijs & King; K. tatiaraensis Leijs & King and K.

Modeling of steroid estrogen contamination in UK and South Australian rivers predicts modest increases in concentrations in the future.

The prediction of risks posed by pharmaceuticals and personal care products in the aquatic environment now and in the future is one of the top 20 research questions regarding these contaminants following growing concern for their biological effects on fish and other animals. To this end it is important that areas experiencing the greatest risk are identified, particularly in countries experiencing water stress, where dilution of pollutants entering river networks is more limited. This study is the first to use hydrological models to estimate concentrations of pharmaceutical and natural steroid estrogens in a water stressed catchment in South Australia alongside a UK catchment and to forecast their concentrations in 2050 based on demographic and climate change predictions.

Changes in character of organics in the receiving environment of effluent from a sulphite pulp mill.

Purpose: The characteristics of organics in sulphite pulp mill effluent and in the receiving environment of effluent discharge were investigated to assess the basis for the persistence or attenuation of colour.

Methods: Characterization of organics was conducted through determination of SUVA, specific colour, and molecular weight distribution of organics using high performance size exclusion chromatography and by solid-state (13) C cross polarization (CP) NMR. The characteristics of organics from mill wastewater before and after secondary aerobic treatment, followed by lime treatment and from the receiving environment, an enclosed brackish lake were compared.

A trait database of stream invertebrates for the ecological risk assessment of single and combined effects of salinity and pesticides in South-East Australia.

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.

The definition of species richness used by species sensitivity distributions approximates observed effects of salinity on stream macroinvertebrates.

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).

A similarity-index-based method to estimate chemical concentration limits protective for ecological communities.

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 samples.