Fran Sheldon

• BSc (Hons) PhD
• Professor at Griffith University

Decomposition of plant litter is a key ecological process in streams, whose contribution to the global carbon cycle is large relative to their extent on Earth. We examined the mechanisms underlying the temperature sensitivity (TS) of instream decomposition and forecast effects of climate warming on this process. Comparing data from 41 globally dist...

Inland river and groundwater systems in Australia, as elsewhere, have been heavily overexploited, modified and degraded and are subject to increasing pressures from anthropogenic activities and climate change. Here, we propose the following nine priority actions to repair these critical parts of our landscape not currently being implemented or not...

The supplementary material contains details of the methods used for each indicator and references to the sources of data.

Context Rigorous monitoring and reporting helps determine effectiveness of water reforms. We assess implementation of the Murray–Darling Basin Plan, intended to ensure that water resources are used sustainably. Many aspects of Basin Plan implementation are poorly monitored and reported, owing to fragmented and inadequate data collection across juri...

Context In implementing the Murray–Darling Basin Plan, jurisdictions have defined environmental water requirements (EWRs) for sites along Basin rivers. EWRs are the flows (frequency, magnitude, duration, and timing) required to achieve environmental outcomes; they are derived from flow-ecology relationships by using best available scientific knowle...

Most freshwater mussels have larvae (glochidia in Unionidae, Margaritiferidae and Hyriidae) that are parasitic on fishes. This study describes and compares the diversity of glochidia among 17 species of Australasian Hyriidae. Here, scanning electron microscopy was used to illustrate shell morphology, while patterns of diversity in size, shape and m...

Most freshwater mussels have larvae (glochidia in Unionidae, Margaritiferidae and Hyriidae) that are parasitic on fishes. This study describes and compares the diversity of glochidia among 17 species of Australasian Hyriidae. Here, scanning electron microscopy was used to illustrate shell morphology, while patterns of diversity in size, shape and m...

Environmental water requirements (EWRs) are the flows required to keep aquatic ecosystems healthy. We explored if EWRs had been met across aquatic ecosystems in the Murray–Darling Basin over the last four decades, finding that at 65% of assessed sites they had not been achieved. The most recent decade since Basin Plan legislation has seen some impr...

Wetlands are increasingly valuable under climate change in terms of their ecological functions, ecosystem services, and biodiversity. Simultaneously, wetlands are hotspots for anthropogenic activity due to their high soil fertility and water supply, and have been subject to significant modification, degradation, and staggering losses. With climate...

Groundwater represents a critical water source for plants, especially during drought, with continuous groundwater availability widely associated with the presence of ecological refugia and the preservation of biodiversity during periods of adverse conditions. Here, we present a systematic quantitative literature review of global groundwater and eco...

Australia’s freshwater habitats are facing ever-increasing challenges. Increasing frequency and severity of droughts, fires, torrential rains, and floods have been on the rise in recent decades with some of the most severe events on record having ensued in the past decade. Under climate change, this trend is expected to continue. River regulation a...

Revegetating abandoned agricultural lands is vital to restoring critical ecological functions and services. Natural regeneration, whereby vegetation regrows via the seeds already present within the landscape, has shown to be an effective approach to restoring large agricultural areas, although more research is required to understand the regenerativ...

In semi-arid landscapes, water regimes play a critical role in shaping patterns of vegetation regeneration. In riparian and floodplain habitats, however, the importance of flooding versus rainfall is poorly established for many species and habitats. Here, we present the results of a field experiment designed to investigate the establishment respons...

In the face of mounting environmental and political challenges in river management, accurate and timely scientific information is required to inform policy development and guide effective management of waterways. The Murray–Darling Basin is Australia's largest river system by area and is the subject of a heavily contested series of water reforms re...

Many water scientists aim for their work to inform water policy and management, and in pursuit of this objective, they often work alongside government water agencies to ensure their research is relevant, timely and communicated effectively. A paper in this issue, examining 'Science integrity, public policy and water governance in the Murray-Darling...

In late 2018 to early 2019, three significant fish death events occurred in the Lower Darling River, Australia, with mortality estimates of millions of fish. We examined the proximate and ultimate causes of these events. We determined that not only were the conditions existing at the time a significant contributing factor, but that antecedent condi...

Data collection for fresh-water regions of The Ecosystem Health Monitoring Program (EHMP), in southeast Queensland, Australia, involves the sampling of over 130 sites among 19 catchments twice per year and has been ongoing for over ten years. The sampling design was derived following an exhaustive process of indicator and site selection to develop...

Socio-economic and environmental drivers are causing large scale abandonment of agricultural land worldwide. Simultaneously, there is growing recognition that urgent and widespread revegetation is required in our agricultural landscapes to restore biodiversity, ecosystem services and promote carbon sequestration. The design of effective revegetatio...

The relationship between detritivore diversity and decomposition can provide information on how biogeochemical cycles are affected by ongoing rates of extinction, but such evidence has come mostly from local studies and microcosm experiments. We conducted a globally distributed experiment (38 streams across 23 countries in 6 continents) using stand...

In the face of mounting environmental problems, it is essential that accurate and timely scientific information is available to inform policy development and guide management. Scientists have specialised knowledge necessary for evidenced-based decision making, but despite extensive literature on the interface between science and policy, there is li...

Running waters contribute substantially to global carbon fluxes through decomposition of terrestrial plant litter by aquatic microorganisms and detritivores. Diversity of this litter may influence instream decomposition globally in ways that are not yet understood. We investigated latitudinal differences in decomposition of litter mixtures of low a...

Running waters contribute substantially to global carbon fluxes through decomposition of terrestrial plant litter by aquatic microorganisms and detritivores. Diversity of this litter may influence instream decomposition globally in ways that are not yet understood. We investigated latitudinal differences in decomposition of litter mixtures of low a...

Nutrients are a fundamental determinant of broad scale patterns in the benthic algal community of stream ecosystems. Excessive inputs of nutrients such as nitrogen and phosphorus into upland streams may result in significant impacts on benthic algal communities. In upland streams, diatoms are the most abundant and diverse taxonomic group in benthic...

The Nature Needs Half (NNH) movement aims to protect 50 % of the earth. That said protected area designation usually neglects freshwater ecosystems and biodiversity. We assessed protection of the surface area of lakes, length of river reaches, habitat area of fish and odonate species within the terrestrial-focused protected areas of Bhutan that mee...

The conservation movement “Nature Needs Half” (NNH) aims to protect 50% of the earth by 2050. But increase in total protected area (PA) coverage alone does not guarantee adequate species protection, and identifying conservation priority areas that meet specific species conservation targets is suggested as a way forward. Further, PAs are dynamic ent...

• Understanding soundscapes, that is, the totality of sounds within a location, helps to assess nature in a more holistic way, providing a novel approach to investigating ecosystems. To date, very few studies have investigated freshwater soundscapes in their entirety and none across a broad spatial scale. • In this study, we recorded 12 freshwater...

The distribution and population structure of organisms is governed by a broad suite of biotic and abiotic variables, interacting across multiple scales. Recruitment is a key demographic process critical to the maintenance of successful populations. Isolating and quantifying the multiscale environmental drivers of recruitment is vital for species co...

Converting forest to pasture can alter the roles of biota in ecosystem functioning, while vegetation restoration should arguably assist functional recovery. Since tests of this are scarce, this study quantifies both litter decomposition rates and their association with decomposer invertebrates, across 25 sites representing different phases of defor...

Large rivers dominate the world's terrestrial surface, yet we are still learning of their structure, how they function, and whether they are different not only from each other, but also from smaller rivers. There is a benefit in framing large rivers as complex adaptive systems, as they contain essential features of these entities, the emergent prop...

The cover image is based on the Special Issue Paper LARGE RIVERS AS COMPLEX ADAPTIVE ECOSYSTEMS by Martin Thoms and Fran Sheldon, https://doi.org/10.1002/rra.3448. Cover image © David Mussred.

Bhutan is recognized for conservation success under its pro‐environmental development philosophy Gross National Happiness (GNH). However, an increase in area coverage alone cannot track the true contribution of protected areas (PAs) to biodiversity conservation. Capturing PA dynamism by tracking PADDD (PA downgrading, downsizing, and degazettement)...

In forestry, selective timber harvesting best management practices (BMPs) are widely adopted to mitigate the effects of clearfell harvesting on stream ecosystems. However, there have been surprisingly few studies experimentally assessing the effects of selective harvesting on freshwater benthic macroinvertebrate assemblages and how anthropogenic di...

Freshwater mussels are declining globally, and effective conservation requires prioritizing research and actions to identify and mitigate threats impacting mussel species. Conservation priorities vary widely, ranging from preventing imminent extinction to maintaining abundant populations. Here, we develop a portfolio of priority research topics for...

Best management practices (BMPs) for forestry activities have been developed to mitigate the impacts of timber harvesting on stream ecosystems in New South Wales, Australia. These BMPs include selective harvesting within the catchment, exclusion of harvesting in riparian zones, and restrictions on harvesting and machinery operations during wet weat...

Knowledge of cryptic species distributions and their relationships with environmental factors may be extremely valuable for biodiversity conservation. In freshwater ecosystems, morphologically cryptic species often have different geographic distributions that can overlap to varying extents. The importance of differential species responses to enviro...

Adequate protection of groundwater dependent vegetation (GDV) at the landscape scale (> 10⁴ km²) is often hampered as their extent is poorly mapped. Remote sensing datasets have previously been used to delineate GDV by analysing both actual, and changes, in green biomass over space and time. The rationale behind such approaches is based on the phen...

• Freshwater ecosystems and their associated biota are under increasing threats from multiple stressors including climate and land‐use change. The conservation of these ecosystems must be based on an integration of data including species physiological tolerances, the biotic and abiotic drivers of the distribution of populations, and demographic pro...

All communities may re-assemble after disturbance. Predictions for re-assembly outcomes are, however, rare. Here we model how fish communities in an extremely variable Australian desert river re-assemble following episodic floods and drying. We apply information entropy to quantify variability in re-assembly and the dichotomy between stochastic and...

Shell shape varies markedly in freshwater mussels in the order Unionoida. Freshwater mussels belonging to the genus Velesunio (Family Hyriidae) are distributed widely in the rivers and wetlands of Australia, with recent molecular evidence suggesting at least three more species within the genus Velesunio than previously described using shell morphol...

Benthic diatoms have been universally used as indicators to assess water quality in lotic ecosystems. However, most diatom-based indices developed in Europe have not been widely used or tested in other continents such as Asia or Oceania. This study compared the performance of 14 widely-applied diatom indices in assessing ecological conditions in su...

Addressing the issue of degraded waterways nationally will cost billions of dollars; in Southeast Queensland (SEQ) alone it is estimated that it will cost $500M. Fundamental research is needed to ensure such efforts achieve the desired outcomes. Previous research has shown riverbank erosion is a key stressor for water quality. This project will lin...

Our lack of knowledge on the spatiotemporal drivers of the distribution of many freshwater fishes, particularly as they differ among life-history stages, is a challenge to conservation of these species. We used 2-stage hurdle models to investigate drivers of occurrence and abundance of locally threatened adult and juvenile Northern River Blackfish...

Managing and restoring faunal diversity across large areas requires an understanding of the roles of connectivity and dispersal in driving community patterns. We sought to determine the influence of connectivity, water regime, water source, geographical location, and dispersal traits on patterns of aquatic invertebrate diversity across a continent-...

The taxonomic completeness index (ratio of observed to expected species; O/E) is widely used in stream bioassessment programs to infer ecological impairment. However, its sensitivity to detecting anthropogenic disturbances may be reduced by (1) the modelling procedure used to determine the expected species at a site (2) the inability of the index t...

Diatoms (Division Bacillariophyta) commonly dominate benthic algal communities in upland streams and are the major primary producers that sit at the base of food webs. Given their ecological importance, the aim of the present study was to investigate the spatial patterns of freshwater biofilm biomass and diatom assemblage composition in response to...

Algal polyunsaturated fatty acids (PUFA), essential for somatic growth and reproduction of aquatic animals, are influenced by ambient environmental conditions, including light and nutrients. Few studies have addressed the extent to which changes in dietary PUFA can influence stream herbivore PUFA profiles and the implications for stream food webs....

1. While many streams and rivers are dominated by terrestrial inputs of organic carbon, algae are important trophic base for stream food webs. However, the nutritional importance of algae for stream invertebrates has only recently been highlighted. Algae are acknowledged as higher quality food than terrestrial organic matter for the growth and repr...

Algae are higher quality food resources than allochthonous plant litter for stream invertebrates, in part, because of their higher content of polyunsaturated fatty acids (PUFAs). We tested the hypothesis that the algal biofilms that colonize the surfaces of leaf litter improve the nutritional quality of terrestrial inputs for invertebrate shredders...

Recent investigators have emphasized that food quality has greater importance than food quantity for herbivore somatic growth. Herbivore growth is thought to be regulated by light and nutrients through changes in food elemental ratios, but our knowledge of the mechanisms driving grazer growth in stream ecosystems is scarce. We manipulated light (th...

Freshwater ecosystems are declining under climate change and land-use change. To maximize the return on investment in freshwater conservation with limited financial resources, managers must prioritize management actions that are most cost-effective. However, little is known about what these priorities may be under the combined effects of climate an...

Species distribution models are widely used for stream bioassessment, estimating changes in habitat suitability and identifying conservation priorities. We tested the accuracy of three modelling strategies (single species ensemble, multi-species response and community classification models) to predict fish assemblages at reference stream segments i...

Cluster dendrogram showing the 6 groups (red boxes) selected for the community classification models, RF and DFA. (DOCX)

Fish presence-absence data, environmental predictor variables and site locations for the ‘training’, ‘space’, ‘season ‘, ‘time’ and ‘method’ datasets. The ‘time’ and ‘method’ datasets were made available by SEQ Healthy Waterways Partnership and NSW DPI Fisheries, respectively. (XLSX)

Details of predictor variables used for the fish species distribution modelling and rationale for their selection. (DOCX)

Key issues with defining reference condition for stream bioassessment are (1) equivocal definitions of ‘minimally disturbed’ pressure criteria and wide-ranging approaches to site selection, (2) highly modified regions where near-pristine areas do not exist, leading to management decisions based on inconsistent and unquantified benchmarks and (3) co...

Benthic algae play an important role in many stream food webs, not only serving as a major carbon source but also influencing energy transfer as the primary source of polyunsaturated fatty acids ( PUFA ). Dietary deficiency in PUFA can limit animal growth and reproduction. Algal PUFA content can vary considerably in response to abiotic factors. We...

Background / Purpose: Biomonitoring research aims to facilitate evidence-based policies. Recent focus has been moving away from descriptive tools for biotic data, towards holistic and increasingly model-based approaches for assessment (appropriate interpretation of a suite of biotic metrics, e.g., species richness/abundance) and prediction (modelin...

Increased sediment loads from accelerated catchment erosion significantly degrade waterways worldwide. In the South East Queensland region of Australia, sediment loads are degrading Moreton Bay, a Ramsar listed wetland of international significance. In this region, like most parts of coastal Australia, sediment is predominantly derived from gully a...

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Natural abundances of stable isotopes in lotic food webs yield valuable information about sources of organic matter for consumers and trophic structure. However, interpretation of isotopic information can be challenging in the face of variability in organisms at the base of food webs. Unionid and dreissenid mussels, commonly used as baseline organi...

1. Despite a general recognition that benthic macroinvertebrates respond to changes in hydrological connectivity within floodplain ecosystems, no consensus about patterns in community structure and ecosystem processes across large scales and different climates has yet been established. Such knowledge is necessary since anthropogenic activities cont...

Aquatic fauna provide an important subsidy to terrestrial consumers. In the wet–dry tropics, important subsidy from rivers to riparian-zone consumers is expected in the dry season, but this may vary depending on riparian-zone condition. We investigated potential subsidy of aquatic fauna to consumers in riparian zones in two highly seasonal rivers i...

Terrestrial environments allow the adults of some aquatic insects to disperse between headwater streams, which may be important for maintaining population connectivity and persistence. Winged adult stages of aquatic insects are particularly sensitive to degradation of terrestrial habitat, relying on it for food, reproduction and dispersal. In this...

Managing receiving-water quality, ecosystem health and ecosystem service delivery is challenging in regions where extreme rainfall and runoff events occur episodically, confounding and often intensifying land-degradation impacts. We synthesize the approaches used in river, reservoir and coastal water management in the event-driven subtropics of Aus...

Understanding the determinants of species’ distributions and abundances is a central theme in ecology. The development of statistical models to achieve this has a long history and the notion that the model should closely reflect underlying scientific understanding has encouraged ecologists to adopt complex statistical methods as they arise. In this...

This report describes the research undertaken to develop national guidelines for climate adaptation planning for arid zone aquatic ecosystems and freshwater biodiversity. The guidelines focus on the protection of habitats and processes that support the persistence of freshwater biota under a changing climate. They support policy development, planni...

Diatoms have been regularly used as bioindicators to assess water quality of surface waters. However, diatom-based indices developed for a specific geographic region may not be appropriate elsewhere. We sampled benthic diatom assemblages in the upper Han River, a subtropical river in China, to evaluate applicability of 14 diatom-based indices used...

Catchment and riparian degradation has resulted in declining ecosystem health of streams worldwide. With restoration a priority in many regions, there is an increasing interest in the scale at which land use influences stream ecosystem health. Our goal was to use a substantial data set collected as part of a monitoring program (the Southeast Queens...

Alterations to the natural flow regime affect the structure and function of rivers and wetlands and contribute to loss of biodiversity worldwide. Although the effects of flow regulation have been relatively well studied, a lack of synthesis of the ecological consequences of low flows and droughts impedes research progress and our grasp of the mecha...

The host specificity of insects on plants and the resulting insect assemblages characteristic of certain plants are well documented. The majority of studies relate to phytophagous insects and their specialisation on particular host plants. Less documented, however, is the specificity of predatory insects to plant hosts. Contrasting sets of beetle t...

Changes in hydrology through increased imperviousness are seen as one of the major drivers of poor health in urban streams. Flow change can impact instream components directly or through associated changes in water quality and habitat availability. This study explored three sites across an urban gradient in detail to detect the mechanism for poor i...

Human-induced alteration of the natural flow regime is a major threat to freshwater ecosystems and biodiversity. The effects of hydrological alteration on the structural and functional attributes of riverine communities are expected to be multiple and complex, and they may not be described easily by a single model. Based on existing knowledge of ke...