Ben Stewart-Koster

Griffith University · Australian Rivers Institute

Living within planetary limits requires attention to justice as biophysical boundaries are not inherently just. Through collaboration between natural and social scientists, the Earth Commission defines and operationalizes Earth system justice to ensure that boundaries reduce harm, increase well-being, and reflect substantive and procedural justice....

Despite decades of increasing investment in conservation, we have not succeeded in ''bending the curve'' of biodiversity decline. Efforts to meet new targets and goals for the next three decades risk repeating this outcome due to three factors: neglect of increasing drivers of decline; unrealistic expectations and time frames of biodiversity recove...

Many species of tilapia (a collection of fish species from the cichlidae family) have biological traits that make them successful invaders. While widespread herbivory has been observed in many tilapia species, knowledge on habitat preferences and tilapia interactions with native fish food webs is limited. This study used stomach contents and stable...

The Sustainable Development Goals aim to improve access to resources and services, reduce environmental degradation, eradicate poverty and reduce inequality. However, the magnitude of the environmental burden that would arise from meeting the needs of the poorest is under debate—especially when compared to much larger burdens from the rich. We show...

Water resource development can lead to the significant alteration of natural flow regimes, which can have impacts on the many aquatic species that rely on both freshwater and estuarine environments to successfully complete their lifecycles. In tropical northern Australia, annual catches of commercially harvested white banana prawns (WBP) are highly...

Around 36,000 km³ of freshwater flows through rivers and estuarine ecosystems and enter the world’s coastal fishing regions every year. The flow of freshwater and sediments creates regional changes in coastal circulation, stimulates marine productivity and helps define the hydrologic properties of estuarine and oceanic waters. These processes can a...

Defining a safe and just space for the biosphere requires global-scale synthetic measures of functional integrity in relation to Nature’s Contributions to People (NCP). We estimated, based on a systematic review of the literature, the minimum level of functional integrity needed to secure multiple critical ecosystem services, including pollination,...

Environmental assessments increasingly call for just transformations, yet do not offer concrete visions of what these might be. This paper conceptualizes and operationalizes Earth system justice (ESJ) through articulating just ends which minimize significant harm to humans from Earth system change while ensuring access to needed resources for all a...

Hydrological connectivity in river systems facilitates the movement of animals, nutrients, and energy across riverine landscapes but is threatened by climate change and water resource developments. These anthropogenic disturbances are expected to alter connectivity patterns in wet-dry tropical river systems that are driven by a highly variable seas...

The UN 2030 Agenda includes 17 Sustainable Development Goals towards improving access to resources and services, reducing environmental degradation and bringing down inequality. However, there is debate on the magnitude of the environmental burden that would arise from meeting the needs of the poorest, especially compared to much larger burdens fro...

In many parts of the world, conditions for small scale agriculture are worsening, creating challenges in achieving consistent yields. The use of automated decision support tools, such as Bayesian Belief Networks (BBNs), can assist producers to respond to these factors. This paper describes a decision support system developed to assist farmers on th...

Polyunsaturated fatty acids (PUFA) are essential components of cell membranes and reproductive and sensory organs in vertebrates and are largely acquired through their diets. Accordingly, identification of the dietary sources of PUFA is an important consideration in food web studies. We collected fish, macroinvertebrates (aquatic and terrestrial),...

1. Floodplain wetlands provide an important subsidy for riverine food webs as sites of high algal production. However, this subsidy depends on the degree of landscape connectivity during flood pulses, which provides the opportunity for movement of higher order consumers between rivers and floodplains to access these productive habitats. Changes in...

Freshwater ecosystems are highly vulnerable to global warming because 1) their chief drivers, water quality and flow regimes, are highly sensitive to atmospheric warming, and 2) they are already extremely threatened by a wide range of interacting anthropogenic pressures. Even relatively modest global warming of 1.5°C poses a considerable threat to...

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...

Sustainable development demands reliable water resources, yet traditional water management has broadly failed to avoid environmental degradation and contain infrastructure costs. We explore the global-scale feasibility of combining natural capital with engineering-based (green-gray) approaches to meet water security threats over the 21st century. T...

Longitudinal and lateral connectivity is important for mobile aquatic species in rivers for reproductive migrations, recruitment, gene flow and access to food resources across habitat types. Water resource developments such as dams and levees may disrupt these connections, causing river fragmentation and loss of access to highly productive habitats...

Studies of tropical floodplains have shown that algae are the primary source material for higher consumers in freshwater aquatic habitats. Thus, methods that can predict the spatial variation of algal productivity provide an important input to better inform management and conservation of floodplains. In this study, a prediction of the spatial varia...

Ecologists are interested in modeling the population growth of species in various ecosystems. Specifically, logistic growth arises as a common model for population growth. Studying such growth can assist environmental managers in making better decisions when collecting data. Traditionally, ecological data is recorded on a regular time frequency and...

Floodplain wetlands are among the most productive and biodiverse ecosystems on Earth and provide a major subsidy of food resources for consumers in river systems. The basal energy source for those consumers in many systems comes from aquatic algal production influenced by different characteristics of the floodplain environment. Our aim was to estim...

Rivers in tropical systems across the world are well known for their strong connections with floodplain wetlands. However, increased water needs and changing climate could drive water-management policy that leads to major changes in flow or surface water availability. These changes could have deleterious effects on ecological functions and ecosyste...

Ecologists are interested in modeling the population growth of species in various ecosystems. Studying population dynamics can assist environmental managers in making better decisions for the environment. Traditionally, the sampling of species and tracking of populations have been recorded on a regular time frequency. However, sampling can be an ex...

Coastal freshwater supply and demand systems are expected to be significantly affected by changes to both climatic and non-climatic drivers over coming decades. Adapting to these changes to secure adequate freshwater to meet the rising demands of socio-economic development has become a critical task for decision-makers. Whilst a range of adaptation...

Rice-shrimp culture systems occur throughout Asia where there are seasonal alterations of fresh and saltwater availability. During the dry season, black tiger shrimp are grown at low densities, and in the wet season, rice, or rice and shrimp are grown together. Previous studies point to issues with suboptimal rice and shrimp production, due, in par...

Abstract The growing demand for freshwater resources has led to dam construction and water diversions in a majority of the world's large rivers. With an increasing demand for freshwater, trade‐offs between water allocations and the preservation of ecological connections between terrestrial and marine ecosystems are inevitable. The ecological links...

In the age of climate change, increasing populations and more limited resources, efficient agricultural production is being sought by farmers across the world. In the case of smallholder farms with limited capacity to cope with years of low production, this is even more important. To help to achieve this aim, data analytics and decision support sys...

Conservation planning processes and wetland management require spatial estimations of aquatic habitats to support the maintenance of aquatic biodiversity. However, physical access to several wetlands and freshwater habitats can be restricted due to difficult topography and technological limitations associated with ground-based observations. In addi...

Aquatic ecosystems are used for extensive rice-shrimp culture where the available water alternates seasonally between fresh and saline. Poor water quality has been implicated as a risk factor for shrimp survival; however, links between shrimp, water quality and their main food source, the natural aquatic biota inhabiting these ponds, are less well...

Adaptation to drought is particularly challenging on remote island atolls, such as those found in the Republic of the Marshall Islands (RMI), a nation of 58,000 populating 29 low-lying coral atolls spread over >2 million km². Exposure to consecutive atmospheric hazards, such as meteorological floods and droughts diminish scarce water resources and...

• Accurately accounting for flows of energy through food webs is challenging because of the spatial and temporal variability associated with energy production and consumption. Wet–dry tropical rivers have a highly seasonal discharge regime where wet season flows allow access to energy sources (inundated wetlands) that are not available during the d...

The ecological communities supported by freshwater habitats and wetlands that persist from floodplain inundation generate numerous cultural, recreational and economic values via commercial fisheries and other human uses of these habitats. However, the alteration of flow connectivity, degradation, and disruption of physical processes that sustain di...

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...

Bayesian networks (BNs) are widely implemented as graphical decision support tools which use probability inferences to generate "what if?" and "which is best?" analyses of potential management options for water resource management, under climate change and socioeconomic stressors. This paper presents a systematic quantitative literature review of a...

Aquatic ecosystems are exposed to a host of anthropogenic stressors whose combined effect can be synthesized with cumulative stress indices. The reliability of cumulative stress indices depends primarily on: 1) stressor incidence maps derived from remote sensing or modeling but rarely validated against on-the-ground observations , and 2) the weight...

Although health, development, and environment challenges are interconnected, evidence remains fractured across sectors due to methodological and conceptual differences in research and practice. Aligned methods are needed to support Sustainable Development Goal advances and similar agendas. The Bridge Collaborative, an emergent research-practice col...

Although health, development, and environment challenges are interconnected, evidence remains fractured across sectors due to methodological and conceptual differences in research and practice. Aligned methods are needed to support Sustainable Development Goal advances and similar agendas. The Bridge Collaborative, an emergent research-practice col...

• Predator–prey interactions are an inherently local‐scale phenomenon, but the intensity of these interactions can be mediated by abiotic conditions that can exert a multi‐scaled influence through space and time. Understanding how multi‐scale abiotic factors may influence local‐scale biotic processes has proven challenging; however, the hierarchica...

The perception that anthropogenic stressors cause jellyfish blooms is widespread within the scientific literature and media but robust evidence in support of these claims appears scarce. We used a citation analysis of papers published on “jellyfish blooms” to assess the extent to which such claims are made and the robustness of the evidence cited t...

Land and water resource developments have the potential to modify rivers, floodplains, estuaries and coastal waters, changing habitats and ecological processes that support native flora and fauna. The Ecology activity of the Northern Australia Water Resource Assessment (the Assessment) will assess the impacts of potential changes in flow on freshwa...

Mixing models have become requisite tools for analyzing biotracer data, most commonly stable isotope ratios, to infer dietary contributions of multiple sources to a consumer. However, Bayesian mixing models will always return a result that defaults to their priors if the data poorly resolve the source contributions, and thus, their interpretation r...

Efficiencies in farming practice in many parts of South East Asia can make substantial, positive differences to villages and communities. The use of automated decision-assistance tools such as Bayesian Belief Networks (BBNs) can help to accomplish this. For the problem described herein, farmers attempt to grow both rice and shrimp crops in the same...

Springs in the Australian arid zone are distinct from other waterways because they house a large number of endemic species. We aimed to assess spatial patterns in endemic diversity at a basin‐wide scale and whether environmental features can help to explain them. In doing so, we take the opportunity to summarize the current state of conservation in...

• 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...

Mangroves sequester large amounts of carbon (C) and they are increasingly recognized for their potential role in climate change mitigation programs. However, there is uncertainty in the C content of many mangrove forests because the amount of C stored in the roots is usually estimated from allometric equations and not from direct field measurements...

In recent years, across tropical regions of the world, there has been an expansion of integrated farming systems that combine rice and shrimp production. While these systems were developed as a form of crop-rotation – growing rice in the wet season and shrimp in the dry season – some farmers grow both rice and brackish-water shrimp simultaneously d...

A large proportion of the uncertainty surrounding catchment sediment budget modelling has been attributed to sediment supplied from riverbank erosion. Some of the variables influencing riverbank erosion are bend curvature, specific streampower, riparian vegetation, and in some instances sand and gravel extraction. The empirical relationship between...

Coastal ecosystems can be degraded by poor water quality. Tracing the causes of poor water quality back to land-use change is necessary to target catchment management for coastal zone management. However, existing models for tracing the sources of pollution require extensive data-sets which are not available for many of the world’s coral reef regio...

The Mekong Delta is the most important rice- and shrimp-producing region for food and economic security in Vietnam. Rice-shrimp farming is practised where salinity fluctuates substantially between wet and dry seasons. Research points to several potential risk factors for rotational systems, but how these link directly to both rice and shrimp produc...

Coastal ecosystems can be degraded by poor water quality. Tracing the causes of poor water quality back to land-use change is necessary to target catchment management for coastal zone management. However, existing models for tracing the sources of pollution require extensive data-sets which are not available for many of the world’s coral reef regio...

Connectivity is regarded globally as a guiding principle for conservation planning, but due to difficulties in quantifying connectivity empirical data remain scarce. Lack of meaningful connectivity metrics are likely leading to inadequate representation of important biological connections in reserve networks. Identifying patterns in landscape conne...

1.Preventing the arrival of invasive species is the most effective way of controlling their impact. Preventative strategies may be “offensive” aimed at preventing the invader leaving colonised locations, or “defensive” aimed at preventing its arrival at uninvaded locations. The limited resources for invasive species control must be prioritized, par...

Habitat fragmentation is a key anthropogenic factor in biodiversity decline, particularly in aquatic ecosystems. We predicted that differences in fish assemblage composition due to the impact of fragmentation would most strongly affect migratory species, and these effects would be dependent on the interaction between the characteristics of each bar...

Hydrologic metrics have been used widely to quantify flow-ecology relationships; however, there are several challenges associated with their use, including the selection from a large number of available metrics and the limitation that metrics are a synthetic measure of a multi-dimensional flow regime. Using two case studies of fish species density...

Development of skills in science communication is a well-acknowledged gap in graduate training, but the constraints that accompany research (limited time, resources, and knowledge of opportunities) make it challenging to acquire these proficiencies. Furthermore, advisors and institutions may find it difficult to support graduate students adequately...

Predicting how climate change is likely to interact with myriad other stressors that threaten species of conservation concern is an essential challenge in aquatic ecosystems. This study provides a framework to accomplish this task in salmon-bearing streams of the northwestern United States, where land-use related reductions in riparian shading have...

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...

Background/Question/Methods Quantifying the connectivity of fragmented landscapes is essential to modeling and mitigating the spread of non-native species. A key element of the connectivity of a landscape is the degree and extent to which organisms disperse through natural and built environments with human assistance. The goal of this study was t...

Ecologists are frequently confronted with the challenge of accurately modelling species abundance. However, this task requires one to deal with both presence/absence as well as abundance. Traditional Poisson regression models are not ade-quate when attempting to deal with both issues simultaneously. Zero-inflated regression models have been propose...

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...

In this study, relationships between flow variation across multiple temporal scales and the distribution and abundance of three fish species, western rainbowfish Melanotaenia australis, sooty grunter Hephaestus fuliginosus and barramundi Lates calcarifer were examined at eight sampling reaches in the Daly River, Northern Territory, Australia. Disch...

The riverscape concept has gained popularity as a useful framework to understand how local and regional environments affect the distribution and abundance of stream organisms, yet there has been limited progress in advancing this concept from theoretical abstraction to quantitative realization. Recent developments in quantitative ecology provide an...

This article examines the trophic ecology of freshwater fishes (22 species in 15 families) in a wet and dry tropical Australian river of high intra-annual and interannual hydrological variability. Seven major trophic groups were identified by cluster analysis; however, four food items (filamentous algae, chironomid larvae, Trichoptera larvae and Ep...

Summary1. The provision of environmental flows and the removal of barriers to water flow are high priorities for restoration where changes to flow regimes have caused degradation of riverine ecosystems. Nevertheless, flow regulation is often accompanied by changes in catchment and riparian land-use, which also can have major impacts on river health...

This paper describes the relative influence of (i) landscape scale environmental and hydrological factors, (ii) local scale environmental conditions including recent flow history, and (iii) spatial effects (proximity of sites to one another), on the spatial and temporal variation in local freshwater fish assemblages in the Mary River, south-eastern...