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Coastal freshwater wetlands (CFWs) are among the most understudied wetlands globally and are highly vulnerable to projected climate changes. To address CFW knowledge gaps in south-east Queensland, Australia, we surveyed the floristic composition and structure of wooded CFWs and explored variation in vegetation patterns in relation to selected environmental drivers. Understorey and shrub assemblages were surveyed using a cover-class scale and stem counts for tree species abundance. Vegetation structure attributes (stem density, basal area) were calculated from survey data. Redundancy analysis was used to investigate drivers of vegetation structure and the species composition of each stratum. Vegetation structure patterns were associated with gradients of rainfall, soil moisture, salinity and pH. Understorey species composition was associated with wallum wetland species, native perennial grass and herb species, and vegetation patterns of the canopy. Common CFW species, namely Melaleuca quinquenervia and Eucalyptus tereticornis, dominated tree assemblage variation. Overall, CFW vegetation exhibited strong associations with gradients of salinity, rainfall, groundwater dependence and disturbance. Alterations to key drivers of vegetation pattern with future climate changes are likely to markedly influence the composition, structure and function of CFW vegetation communities. Action is therefore required to maintain CFW vegetation communities and ecological function in these diverse and unique wetland systems.

Climate change poses significant threats to wellbeing and livelihoods of people and the ecosystems in many Small Island Developing States (SIDS). Adaptation solutions must counteract these threats while also supporting development in vulnerable SIDS. Suitable options need to ensure that connections between the social, economic, and environmental dimensions of socio-economic systems are defined in a way that can support how decisions are made (and by whom) and how these can impact on other parts of these systems. This is particularly important in many Pacific SIDS, where communities practise customary natural resource management and continue to rely on local natural resources. In this study, we model the anticipated impacts of climate change and the benefits of the ecosystem-based adaptation (EbA) approaches on community wellbeing in Vanuatu. To do this, we applied participatory and expert elicitation methods to develop a Bayesian network model, which was designed to evaluate community wellbeing responses at four explicit spatial scales. The model includes both acute and chronic impacts of climate change, the impact of coral bleaching, and the potential loss of Vanuatu’s fringing coral reefs. The model predicts that all proposed EbA interventions will have a positive impact on wellbeing in all four locations to some degree, by either directly improving the integrity of Vanuatu’s ecosystems or by protecting these ecosystems as a positive spill-over of related actions. Significantly, it also predicts that if climate change exceeds 1.5 °C of warming, the costs of achieving the same level of wellbeing are increased.

Developing countries face risks from natural hazards that are being amplified by climate change. Selection of effective adaptation interventions to manage these risks requires a sufficiently accurate assessment of the coastal hazard at a given location. Yet challenges remain in terms of understanding local coastal risks given the coarseness of global wave models and the paucity of locally scaled data in most developing countries, including Small Island Developing States (SIDS) like Vanuatu. The aim of this paper was to examine the differences in hazard assessment and adaptation option selections arising from analyses using globally versus locally scaled data on coastal processes. As a case study, we focused on an eroding cliff face in Port Resolution on Tanna Island, Vanuatu, which is of concern to the local community and government authorities. The coastal process modelling revealed that the global wave data generated unrealistically high predictions of wave height within Port Resolution bay. Expensive engineering adaptations designed to provide coastal protection were therefore likely to fail in preventing ongoing cliff erosion. In this case, the best adaptation solution involves changing land use to revegetate and help stabilise the cliff top. Our case study highlights the importance of accurate hazard assessment, especially in data poor regions where extrapolation of global datasets and models in the absence of local data can result in poor adaptation decision making. Furthermore, the multidisciplinary approach applied here can be applied in other data-poor regions to strengthen analyses exploring the benefits of local adaptation interventions.

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 options may be available, the complexity and interconnectedness of water resource systems make it challenging to identify which options are likely to be most feasible and effective. Here, we present a Bayesian decision network (BDN) that was co-developed with local experts to identify appropriate adaptation options for freshwater management under both current and likely future conditions in the Da Do Basin of coastal Vietnam. Potential adaptation options were prioritised according to cost-effectiveness based on relative costs incurred and relative utilities delivered across a range of future scenarios. The BDN model indicated that cost-effectiveness of adaptation options varied between future scenarios. Constructing pumping stations was the most cost-effective option under climate change scenarios, whilst a higher water price was the most cost-effective option under non-climatic changes. Under combined climatic and non-climatic changes, constructing pumping stations in combination with increasing water prices provided the most cost-effective option. The model affords an opportunity for decision-makers in the Da Do Basin to prioritise and evaluate appropriate and feasible adaptation actions under different scenarios with respect to multiple drivers.

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 erode the resilience of island communities. Drought impact mitigation measures must supply emergency drinking water to stricken communities, while simultaneously conserving natural sources in order to reduce their vulnerability to subsequent events. Household surveys (n = 298) and focus group discussions (n = 16) in eight RMI communities revealed that 86% of households have experienced drought and 88% reported using multiple water sources to meet normal household needs. With no surface water and a thin freshwater lens (FWL), rainwater collected from rooftops is the most common household water source. The traditional use of carved hollows in the base of coconut trees to collect rainwater (“Mammaks”) appears to have been displaced by large rainwater tanks. However, rationing of rainwater for consumption only during drought was widely reported, with private wells supporting non-consumptive uses. Reverse osmosis (RO) desalination units have provided relief during drought emergencies but concerns have been raised around dependency, maintenance challenges, and loss of traditional water practices. Most notably, RO use has the potential to change the anthroposhpere by adversely affecting the FWL; 86% of RO units were installed at island-centre where excessive pumping can cause upconing, making the FWL brackish. Balancing the introduction of desalination technology to mitigate water shortages with maintenance of traditional water conservation practices to preserve the quantity and quality of the FWL is a promising strategy on island atolls that requires further investigation.

Coastal freshwater wetlands are amongst the world’s most modified but poorly researched ecosystems and some of the most vulnerable to climate change. Here, we examine vegetation resilience in coastal wetlands of subtropical Australia to altered salinity and flooding regimes likely to occur with climate change. We conducted field surveys and glasshouse experiments to examine plant diversity and regeneration responses of understorey and canopy species across four habitats. Vegetation composition, but not richness, varied between seaward and inland habitats while soil seed bank diversity was greatest in more inland sites. Experimental salinity and flooding treatments strongly influenced emergence from seed banks with most species germinating under fresh, waterlogged conditions and very few in saline treatments. Composition of emerging seedling assemblages was similar across habitats and treatments but differed considerably from the extant vegetation, indicating a relatively minor role of soil seed banks in sustaining current vegetation structure in this wetland. An exception to this was Sporobolus virginicus (marine couch) which was common in both the vegetation and seed banks suggesting a high capacity for this species to re-establish following disturbances. Seedlings of dominant canopy species also reacted strongly to increased salinity treatments with decreased survivorship recorded. Overall, our findings suggest a high probability of constrained vegetation regeneration in this wetland in response to key projected climate change disturbances with implications for vegetation diversity at a landscape scale including declines in the extent and diversity of more landward vegetation communities and expansion of salt-tolerant marshes dominated by Sporobolus virginicus.

Water resources management faces many challenges in coastal areas of developing countries, where climate change coupled with high rates of population growth and urbanization have the potential to cause severe water scarcity. Of particular concern, are sea level rise and altered precipitation regimes that will influence spatial and temporal patterns of river discharge, water levels and saltwater penetration in estuaries. A sound understanding of factors affecting the vulnerability of coastal freshwater systems is therefore needed to mitigate the potential impacts of climatic and non-climatic changes. In this study, a system dynamics modeling approach was employed to explore the vulnerability of the coastal freshwater system in Da Do Basin, Vietnam to projected sea level rise, upstream flow decline and socio-economic development. This system includes the Da Do River and irrigation channels that receive freshwater through sluice gates from the Van Uc and Lach Tray rivers. The model was developed as a learning tool for decision-makers to improve their understanding of the spatial and temporal dynamic behaviors of the system and to inform adaptation decision-making by allowing exploration of plausible future scenarios. The model was developed, calibrated and validated using both historical data and expert knowledge elucidated via stakeholder consultation. Model results indicate that under current conditions, freshwater availability is sufficient to meet existing domestic, industrial and agricultural demands. However, the coastal freshwater system changes significantly and collapses under several plausible future scenarios. Future projections suggest that declining upstream flows will be the strongest threat to the system's vulnerability. System dynamics models enable consideration of the interactive effects of a range of climatic and non-climatic drivers on water resources availability thereby facilitating improved planning for collective and proactive adaptation actions to efficiently secure freshwater resources to support socio-economic development of coastal basins in the face of climate change.

Global water research and monitoring typically focus on the household's “main source of drinking-water.” Use of multiple water sources to meet daily household needs has been noted in many developing countries but rarely quantified or reported in detail. We gathered self-reported data using a cross-sectional survey of 405 households in eight communities of the Republic of the Marshall Islands (RMI) and five Solomon Islands (SI) communities. Over 90% of households used multiple sources, with differences in sources and uses between wet and dry seasons. Most RMI households had large rainwater tanks and rationed stored rainwater for drinking throughout the dry season, whereas most SI households collected rainwater in small pots, precluding storage across seasons. Use of a source for cooking was strongly positively correlated with use for drinking, whereas use for cooking was negatively correlated or uncorrelated with nonconsumptive uses (e.g., bathing). Dry season water uses implied greater risk of water-borne disease, with fewer (frequently zero) handwashing sources reported and more unimproved sources consumed. Use of multiple sources is fundamental to household water management and feasible to monitor using electronic survey tools. We contend that recognizing multiple water sources can greatly improve understanding of household-level and community-level climate change resilience, that use of multiple sources confounds health impact studies of water interventions, and that incorporating multiple sources into water supply interventions can yield heretofore-unrealized benefits. We propose that failure to consider multiple sources undermines the design and effectiveness of global water monitoring, data interpretation, implementation, policy, and research.

Pacific Island Countries (PICs) lag behind global trends in water, sanitation and hygiene (WaSH) development. We conducted a systematic search of all English language papers (published before February 2015) about WaSH in PICs to evaluate the state of the peer-reviewed literature and explore thematic findings. A total of 121 papers met the criteria for full-text review following an initial search result of more than 6,000 papers. Two reviewers independently assessed the quality and relevance of each article and consolidated their findings according to four emergent themes: public health, environment, emergency response and interventions, and management and governance. Findings indicate a knowledge gap in evidence-guided WaSH management strategies that advocate for human health while concurrently protecting and preserving drinking water resources. Extreme weather events threaten the quantity and quality of limited freshwater resources, and cultural factors that are unique to PICs present challenges to hygiene and sanitation. This review highlights the strengths and weaknesses of the peer-reviewed literature on WaSH in PICs, addresses spatial and temporal publication trends, and suggests areas in need of further research to help PICs meet development goals.

The routine use of multiple water sources to meet household water needs is widely practiced and has been reported in many developing countries. However, it is typically neglected by implementers, development organizations, and researchers who tend to focus exclusively on the “main source of drinking water.” In this Perspective, we explain the nature and scope of multiple water source use (MWSU) at the household level in developing countries. We also describe the implications of MWSU for human health and water resilience, and identify key knowledge gaps, risks, and opportunities associated with MWSU. Finally, we argue that understanding MWSU is feasible for researchers and implementers and is essential for properly designing research studies and water supply projects.

Urbanization significantly alters the hydrology of catchments, the transport of sediment, nutrients, and pollutants and consequently has a degrading impact on urban stream biota. In response to these impacts, water sensitive urban design (WSUD) is often seen as an approach to reduce the hydrological and pollutant risks for receiving waterbodies. We explored the impacts of urbanization across three stream types: an urban system, one subject to upstream WSUD development, and a forested stream. Our results suggested that there were strong differences in the hydrology, water quality, and macroinvertebrate assemblage composition between the FOREST site and the two sites impacted by urbanization; the WSUD and the URBAN sites. Despite the upstream WSUD development, both the WSUD and URBAN sites had hydrology characterized by higher rates of rise and fall of flood peaks. However, very little variation in macroinvertebrate assemblage composition across the three streams could be directly attributed to the changed hydrology. Rather it was differences in water quality that showed the strongest influence on the biota, suggesting that even when measures are implemented to help restore more natural flow patterns, degraded water quality can have an overriding influence on stream ecosystem health.

Bayesian belief networks (BBNs) are probabilistic graphical models that can capture and integrate both quantitative and qualitative data, thus accommodating data-limited conditions. This paper systematically reviews applications of BBNs with respect to spatial factors, water domains, and the consideration of climate change impacts. The methods used for constructing and validating BBN models, and their applications in different forms of decision-making support are examined. Most reviewed publications originate from developed countries (70%), in temperate climate zones (42%), and focus mainly on water quality (42%). In 60% of the reviewed applications model validation was based on the expert or stakeholder evaluation and sensitivity analysis, and whilst in 27% model performance was not discussed. Most reviewed articles applied BBNs in strategic decision-making contexts (52%). Integrated modelling tools for addressing challenges of dynamically complex systems were also reviewed by analysing the strengths and weaknesses of BBNs, and integration of BBNs with other modelling tools. The application of BBNs to water resource management was rarely applied in developing countries and in tropical regions.Only 8% reviewed papers explored potential impacts of climate change on water resources.Only 11% and 6% of reviewed articles applied influence diagrams and Object-Oriented Bayesian Networks respectively.Most reviewed articles applied BBNs in strategic decision-making contexts (52%) for water resource management.Results from BBN models were rarely compared or tested against other modelling approaches to validate their performance.

Modern stormwater treatment assets are a form of water sensitive urban design (WSUD) features that aim to reduce the volumes of sediment, nutrients and gross pollutants discharged into receiving waterways. Local governments and developers in urban areas are installing and maintaining a large number of stormwater treatment assets, with the aim of improving urban runoff water quality. Many of these assets take up significant urban space and are highly visible and as a result, community acceptance is essential for effective WSUD design and implementation. However, community perceptions and knowledge about these assets have not been widely studied. This study used a survey to investigate community perceptions and knowledge about stormwater treatment assets in Brisbane, Australia. The results suggest that there is limited community knowledge of these assets, but that communities notice them and value their natural features when well-maintained. This study suggests that local governments may be able to better inform residents about the importance of these assets, and that designing for multiple purposes may improve community acceptance and support for the use of Council funds to maintain them.

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 algal communities. In this study, benthic algal biomass and diatom community responses to in situ nitrogen and phosphorus enrichment were investigated by conducting an in-stream nutrient diffusing substrate experiment at high and low ambient nutrient concentration sites. Nitrogen was found to be the primary limiting nutrient across all sites, regardless of the ambient nutrient concentrations. In general, enrichment relieved nutrient limitation, promoting the dominance of a smaller suite of eutrophic species in the community. This was particularly evident in the low ambient nutrient sites where oligotrophic species initially dominated the community. This study identified diatom species with competitive advantage under nutrient enriched conditions and further the understanding of diatom species competition for multiple nutrients. Five diatom nutrient trait groups differentiate nutrient generalists and specialists and identifies potential indicator species based on their responses to specific enrichment treatments.

Freshwater inflows play an important role in delivering dissolved organic carbon (DOC) to estuaries. Episodic inputs of DOC may support increased bacterial production. However, the role of DOC in supporting zooplankton production is widely debated. To evaluate this role we performed an in situ mesocosm experiment in the Bega River estuary, Australia. We added a DOC leachate derived from terrestrial vegetation to 400 L mesocosm bags as treatments of +1.5, +3, and +16 mg C L−1 and monitored changes in carbon, nitrogen, phosphorus, bacteria, chlorophyll a (Chl a), and zooplankton over 22 d. Bacterial biomass peaked at day 2 and was highest in the +16 mg C L−1 treatment. Chl a was not significantly different between treatments. Mesozooplankton was dominated by copepodites of Gladioferens pectinatus and Sulcanus conflictus between days 5–9 and by adults between days 9–15. Significantly higher numbers of copepods were present in the +16 treatment followed by the +3 mg C L−1 treatment compared with the controls. Stable carbon isotope signatures of copepods in the +16 mg C L−1 treatment were significantly different from the control and showed leachate carbon supported between 29.3% and 55.8% of copepod biomass. These results suggest that the impact of allochthonous DOC loading events on estuarine zooplankton occurs over short periods, and that the magnitude of response is, in part, controlled by the quantity of bioavailable DOC loaded to the system. Our findings underscore the importance of microbial dynamics stimulated by DOC loading events from freshwater inflows as a trophic path in estuarine food webs.

© 2015 Environment Institute of Australia and New Zealand Inc. Understanding longitudinal variation in water quality along rivers and how they are influenced by large dams is important for both ecological theory and river management. This study examines longitudinal changes in water quality downstream of a large bottom release dam (Lake Copeton) on the Gwydir River, Australia. We compared longitudinal changes in water quality variables from sites upstream and downstream of Lake Copeton over a two-year period and a total river distance of approximately 200 km. Lake Copeton acted as a source of nitrogen as nitrogen oxides (NOx) and phosphorus as filterable reactive phosphorus (FRP). A significant increase in the concentration of NOx and FRP was evident downstream of the dam, particularly in summer with elevated concentrations detected up to 60 km downstream. Significantly lower chlorophyll a (Chl-a) concentrations and electrical conductivity (EC) were evident below the dam. Mean nutrient concentrations declined with increased distance downstream of Lake Copeton while Chl-a concentrations increased, suggesting uptake by autotrophs. This study suggests that Copeton Dam disrupts the river continuum for nutrients, Chl-a and EC as predicted by the serial discontinuity concept, with recovery occurring approximately 60 km downstream.

Pacific Island Countries (PICs) lag behind global trends in water, sanitation and hygiene (WaSH) development. We conducted a systematic search of all English language papers (published before February 2015) about WaSH in PICs to evaluate the state of the peer-reviewed literature and explore thematic findings. A total of 121 papers met the criteria for full-text review following an initial search result of more than 6,000 papers. Two reviewers independently assessed the quality and relevance of each article and consolidated their findings according to four emergent themes: public health, environment, emergency response and interventions, and management and governance. Findings indicate a knowledge gap in evidence-guided WaSH management strategies that advocate for human health while concurrently protecting and preserving drinking water resources. Extreme weather events threaten the quantity and quality of limited freshwater resources, and cultural factors that are unique to PICs present challenges to hygiene and sanitation. This review highlights the strengths and weaknesses of the peer-reviewed literature on WaSH in PICs, addresses spatial and temporal publication trends, and suggests areas in need of further research to help PICs meet development goals.

Climate change threatens water, sanitation and hygiene (WaSH) facilities and services, as these are intimately linked to the water cycle and are vulnerable to changes in the quantity and quality of available water resources. Floods and droughts, which pollute and reduce water delivery respectively, have now become a perennial issue to deal with in the northern regions of the country, including the Bolgatanga Municipality. This study aimed to assess the degree to which climate change adaptation measures are mainstreamed into the WaSH development planning process in Ghana. Stakeholders from government and non-government agencies were interviewed to gain perspectives on the threat of climate change, the inclusion of climate change in WaSH planning and the barriers preventing mainstreaming. In general, despite awareness and concern about climate change, adaptation measures have been regarded to be far away from the immediate concerns of WaSH development planning. Most of the current measures are reactive and respond to environmental issues rather than to climate change stressors. In essence, stakeholders expressed the view that the adaptive capacity of the Municipality was low and that mainstreaming has not yet occurred. Despite the lack of progress, there are great opportunities for mainstreaming climate change adaptation into planning through increasing awareness and capacity, legislative and institutional changes and the development of participatory systems to provide early warning systems and disaster risk analyses that will inform future planning.

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 socio-economic stressors. This paper presents a systematic quantitative literature review of applications of BNs for decision support in water resource management. The review quantifies to what extent different types of data (quantitative and/or qualitative) are used, to what extent optimization-based and/or scenario-based approaches are adopted for decision support, and to what extent different categories of adaptation measures are evaluated. Most reviewed publications applied scenario-based approaches (68%) to evaluate the performance of management measures, whilst relatively few studies (18%) applied optimization-based approaches to optimize management measures. Institutional and social measures (62%) were mostly applied to the management of water-related concerns, followed by technological and engineered measures (47%), and ecosystem-based measures (37%). There was no significant difference in the use of quantitative and/or qualitative data across different decision support approaches (p = 0.54), or in the evaluation of different categories of management measures (p = 0.25). However, there was significant dependence (p = 0.076) between the types of management measure(s) evaluated, and the decision support approaches used for that evaluation. The potential and limitations of BN applications as decision support systems are discussed along with solutions and recommendations, thereby further facilitating the application of this promising decision support tool for future research priorities and challenges surrounding uncertain and complex water resource systems driven by multiple interactions amongst climatic and non-climatic changes.

The investigation of multiple sources in household water management is considered overly complicated and time consuming using paper and pen interviewing (PAPI). We assess the advantages of computer-assisted personal interviewing (CAPI) in Pacific Island Countries (PICs). We adapted an existing PAPI survey on multiple water sources and expanded it to incorporate location of water use and the impacts of extreme weather events using SurveyCTO on Android tablets. We then compared the efficiency and accuracy of data collection using the PAPI version (n = 44) with the CAPI version (n = 291), including interview duration, error rate and trends in interview duration with enumerator experience. CAPI surveys facilitated high-quality data collection and were an average of 15.2 min faster than PAPI. CAPI survey duration decreased by 0.55% per survey delivered (p < 0.0001), whilst embedded skip patterns and answer lists lowered data entry error rates, relative to PAPI (p < 0.0001). Large-scale household surveys commonly used in global monitoring and evaluation do not differentiate multiple water sources and uses. CAPI equips water researchers with a quick and reliable tool to address these knowledge gaps and advance our understanding of development research priorities.

Addressing complex and challenging issues entails access to credible systems information in the form of systems maps or diagrams. The purpose of our paper is to describe a participatory action research (PAR) systems mapping activity that was undertaken by an urban informal settlement community in a small Pacific Island Country. A total of 19 households participated in a systems mapping activity to map a household-level water or sanitation system. The individual household systems maps and related data were then used to construct a de-identified aggregated water, sanitation and hygiene (WaSH) marketing systems map (and accompanying narratives) for the informal settlement. We present the marketing systems map, which delineated a series of marketing exchanges, and report on how the map assisted the community to address a number of expressed needs. We conclude by suggesting that systems mapping is a valuable activity that communities could undertake to generate credible systems information to inform and empower collective planning and actions.

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 organisms in lakes, are uncommon in many river settings and can have variable diets, thus making them unsuitable as a universal baseline for many river food web studies and often forcing reliance on more common benthic insects for this purpose. Turnover rates of body carbon and nitrogen in insects are relatively rapid (1 to 50 days half-life). These rapid turnover rates in primary consumers can result in considerable temporal variability in δ13C that rivals that of algae (>10‰ range within a site). This suggests that using primary consumers as a surrogate baseline for algae may not circumvent the problem of temporal variability and the resultant mismatch of sources with longer-lived, slow-growing secondary and tertiary consumers. There are several strategies for reducing the influence of these confounding factors when bivalves with a known diet are not present. These include sampling over large spatial scales and correlating δ13C of consumers with the source of interest (e.g. benthic algae), sampling baseline organisms multiple times in the weeks preceding sampling of larger consumers (particularly in response to large changes in discharge) and using algal-detrital separation methods and multiple tracers as much as possible. Incorporating some of these recommendations and further exploring variability at the base of the food web will potentially provide greater insights into consumer–resource coupling in running waters and more robust conclusions about food web structure and energy flow in these dynamic systems. Copyright © 2012 John Wiley & Sons, Ltd.

Environmental monitoring is an essential feature of environmental assessment and natural resource management. Whilst the focus of monitoring programs is often on the response of chosen variables to a disturbance of particular concern, it is also important to consider the variability of disturbance pressures in relation to the variability of the ecosystem state. In this paper, we discuss the need to relate environmental variability to disturbance variability in small-scale monitoring programs designed to assess the impact of short-term pulses of visitors on the condition of aquatic ecosystems in protected areas. We use data from protected areas from six Koppen climate zones in Australia to highlight the fact that peaks in visitation do not always coincide with existing monitoring protocols or with optimal times for monitoring on the basis of environmental variability, particularly in relation to rainfall and temperature and, hence, likely biological activity. We highlight how recognising the inter...

Urban land use has increased dramatically over the past few decades. Urban streams are distinguished from forested or agricultural streams, in particular, by their more variable and unpredictable hydrologic pattern. The resulting high variability in nutrient loading is likely to alter the elemental composition of primary producers and, ultimately, to change the elemental composition of other foodweb components. Ecological stoichiometry is a useful framework for improving our understanding of the mass balance of multiple key elements in ecosystems. To this end, the C∶N∶P of key foodweb components were measured in Oxley Creek, an urban catchment in southeastern Queensland, Australia. Ten stream reaches were sampled to explore the spatial variation of C∶N∶P of abundant taxonomic groups across the catchment. Four of these sites were sampled weekly (for 8 wk) to examine temporal variation in elemental composition. Our results suggested that spatial and temporal variation in elemental composition of pri...

Seasonality in tourism is a regular and predictable cycle of visitation across a year. Although seasonality in visitation is extremely common and is known, in principle, often to be driven by temporal changes in a range of natural and institutional factors, the relative importance of different individual pressures has yet to be quantified for any large-scale geographical areas. To assess the relative importance of natural versus institutional factors in driving tourism seasonality, data on visitation patterns were collated from 23 protected areas across six Koppen climate zones in eastern Australia. Analyses sought to determine the degree to which climatic variables (such as mean monthly rainfall and minimum and maximum temperatures) explained visitation patterns, and to understand how these relationships could assist in the prediction of tourism futures. Climate was the principal force driving seasonal patterns of visitation in equatorial, tropical, desert, grassland and temperate zones, whereas...

Understanding longitudinal trends in the processing of carbon in rivers represents a much conceptualised, but infrequently tested, issue in aquatic ecology. In this study, we conducted concurrent longitudinal examinations of three very different rivers in eastern Australia to determine whether general principles in river functioning exist across broad geographic and hydrologic scales. Specifically, we examined trends in ambient basic water chemistry, nutrient concentrations, dissolved organic carbon (DOC), extracellular enzymes and food web structure and functioning and conducted bioassays to examine the degree to which DOC and nutrients limit heterotrophic bacterial respiration. These parameters revealed striking similarities across all sites. For metazoan communities, stable isotope analysis showed that algal carbon was the dominant basal resource utilised by consumers in all three rivers, suggesting that in-stream primary producers strongly underpin trophic pathways regardless of the position within a catchment or catchment condition. Analyses of extracellular enzymes revealed that microbial communities are actively utilising DOC at all sites. In fact, heterotrophic microbial respiration was strongly limited by DOC at all sites, with nutrient additions resulting in only relatively minor increases in respiration. Ultimately, this study demonstrates that DOC and algal carbon are critically important drivers of ecosystem processes in Australian riverine ecosystems. Furthermore, across all of our sites and rivers, ambient nutrient concentrations did not influence carbon processing. The consistent longitudinal trends in river function identified in this study provide useful insights for catchment managers and modellers with respect to identifiying key principles that underpin ecosystem functioning in Australian rivers. Copyright © 2009 John Wiley & Sons, Ltd.

Stream food web function is often assessed using carbon stable isotope assessments of the relative contribution of autochthonous and allochthonous sources of organic matter to consumer diets. As a result, variability in source signatures can strongly influence the assessment of carbon flows. To examine the implications of temporal source variability on food web interpretations, benthic algal δ13C signatures were measured over 8 weeks in five streams in subtropical Queensland, Australia. All food webs were largely driven by benthic algal carbon; however, substantial week-to-week variation in benthic algal δ13C signatures modified the calculated contributions of algae to consumer diets, with differences in autochthonous contributions of up to 11% between weeks. In addition, variable algal signatures led to many occasions in which the δ13C signatures of some consumers was beyond the range of available sources, meaning the mixing model analyses did not have a valid solution. Together, these findings suggest that temporal variability in algal δ13C signatures can strongly influence the interpretation of carbon flows in stream food webs. Future food web studies should assess the temporal variability of sources prior to sampling consumers, in order to characterise end member signatures and their relevance to consumers at the time of collection.

The Intergovernmental Panel on Climate Change has identified Australia as among the developed nations most at risk from climate change effects. Key tourism icon destinations and the tourism sector generally have been identified as being particularly at risk. This paper reports on an interdisciplinary, multi-case study approach to assess tourism stakeholders' knowledge of, and approaches to, climate change adaptation and to explore the potential for building a self-assessment toolkit that can be exported to other tourism destinations. This study examined existing knowledge on anticipated biophysical changes and, through primary research (stakeholder interviews and social learning workshops), gauged the expected adaptive approaches of destination communities and the tourism sector to these changes for 2020, 2050 and 2070. The facilitated workshops generated a common set of adaptation strategies across a diverse set of tourist destinations. A key finding from the workshops is that the tourism sector is not yet ready to invest in climate change adaptation because of the perceived uncertainties. Ongoing leadership for such measures were seen to rest with the public sector, especially local authorities. Whether such assessments can be self-generated or require specialist facilitation remains open to debate.

Growing demand for natural area recreation and tourism has seen a rise in visitor numbers to protected areas. In response, there has been an increase in research into visitor impacts. There has also been increased interest in establishing and maintaining visitor impacts monitoring programmes. Here, we evaluate the relationship between recreation ecology research and visitor impact monitoring and discuss how the aims and scope of these two activities often differ. We highlight that recreation ecologists design observational and experimental treatments to test causal relationships between a particular load or stress and environmental indicator(s) of interest. Some of these studies identify thresholds of concern, with the intention that managers can use thresholds of indicator response in their monitoring programmes. However, agencies interested in monitoring visitor impacts often do not need to establish causality, but rather detect change in the indicator of interest. Therefore, simplified protocols which ...

Carbon and nitrogen stable isotope signatures were used to assess the response of food webs to sewage effluent discharged into two small intermittently open estuaries in northern New South Wales, Australia. One of these systems, Tallows Creek, has a history of direct sewage inputs, whilst the other, Belongil Creek, receives wastewater via an extensive wetland treatment system. The food webs of both systems were driven by algal sources of carbon, reflecting high autotrophic productivity in response to the nutrients entering the system from sewage effluent. All aquatic biota collected from Tallows Creek had significantly enriched δ 15 N signatures relative to their conspecifics from Belongil Creek, indicating that sewage nitrogen had been assimilated and transferred throughout the Tallows Creek food web. These δ 15 N values were higher than those reported from studies in permanently open estuaries receiving sewage effluent. We suggest that these enriched signatures and the transfer of nitrogen throughout the entire food web reflect differences in hydrology and associated nitrogen cycling processes between permanently open and intermittently open estuaries. Although all organisms in Tallows Creek were generally 15 N-enriched, isotopically light (less 15 N-enriched) individuals of estuary perchlet ( Ambassis marianus ) and sea mullet ( Mugil cephalus ) were also collected. These individuals were most likely recent immigrants into Tallows Creek, as this system had only recently been opened to the ocean. This isotopic discrimination between resident (enriched) and immigrant (significantly less enriched) individuals can provide information on fish movement patterns and the role of heavily polluted intermittently open estuaries in supporting commercially and recreationally valuable estuarine species.

Understanding the drivers and implications of anthropogenic disturbance of ecological connectivity is a key concern for the conservation of biodiversity and ecosystem processes. Here, we review human activities that affect the movements and dispersal of aquatic organisms, including damming of rivers, river regulation, habitat loss and alteration, human-assisted dispersal of organisms and climate change. Using a series of case studies, we show that the insight needed to understand the nature and implications of connectivity, and to underpin conservation and management, is best achieved via data synthesis from multiple analytical approaches. We identify four key knowledge requirements for progressing our understanding of the effects of anthropogenic impacts on ecological connectivity: autecology; population structure; movement characteristics; and environmental tolerance/phenotypic plasticity. Structuring empirical research around these four broad data requirements, and using this information to parameterise appropriate models and develop management approaches, will allow for mitigation of the effects of anthropogenic disturbance on ecological connectivity in aquatic ecosystems.

We used natural abundance stable isotopes to establish the structure of the littoral zone food web of an oligotrophic, perched dune lake on Fraser Island, Australia. Mixing model analyses incorporating riparian vegetation, seston, and periphyton sources indicated that periphyton carbon was the most significant food resource for aquatic consumers, despite the abundance of allochthonous carbon sources. In order to examine the consequences of nutrient inputs from tourists visiting this remote lake, repeated additions of low levels of phosphate and 15 N-enriched ammonium nitrate were made to three littoral zone sites. Additions led to significant increases in periphyton chlorophyll a (Chl a) concentrations in enriched sites but had no measurable effect on phytoplankton Chl a concentrations. Periphyton collected 5 h after the first nutrient addition had substantially enriched d 15 N signatures, suggesting that periphyton rapidly assimilated the added nutrients (and 15 N-tracer). After 10 d of additions, all other primary food sources for consumers also became 15 N-enriched, indicating that ongoing nutrient inputs are likely to lead to increased primary production and detrital processing. Substantially enriched consumer d 15 N signatures were also measured, indicating that the added nutrients were assimilated and passed through multiple trophic levels. Our results indicate that ongoing low-level nutrient additions by tourists to oligotrophic lakes could lead to increased primary (periphyton) and secondary (consumer) production. However, increases in periphyton production and biomass accrual could eventually escape control by grazers, leading to adverse ecological and aesthetic effects.

Intensive recreational use of oligotrophic lakes can lead to increases in epilimnetic nutrient concentrations (through direct inputs from urine or re-suspension of sediments) and the development of undesirable algal blooms. Despite these adverse ecological responses to tourist activities, many lake monitoring programs do not address tourist nutrient inputs at appropriate spatial and temporal scales. This paper presents results of investigations aimed at detecting the effects of nutrient inputs to perched dune lakes on Fraser Island, principally through within-lake comparisons of nutrient and algal variables. Nutrient concentrations and algal biomass were measured in heavily visited (disturbed) and inaccessible (reference) sites within five perched dune lakes on Fraser Island, Australia, during the summer of 1999/2000. Whilst nutrient and phytoplankton chlorophyll a concentrations did not differ between sites, periphyton chlorophyll a concentrations were occasionally significantly higher in disturbed sites than in reference sites, particularly in the very popular clear lakes, suggesting that algal growth may be enhanced by tourist activities. Experimental manipulations of nitrogen and phosphorus concentrations in algal (phytoplankton and periphyton) bioassays were undertaken in each lake over the 2000/2001 summer, to assess algal responses to nutrient additions. The response of phytoplankton communities to nutrient additions varied greatly between lakes, with evidence of limitation or co-limitation by nitrogen and phosphorus in all systems. Periphyton biomass showed similar trends to phytoplankton in some lakes, but these were not significant. Nutrients added to lakes by tourists are likely to be rapidly assimilated by littoral zone periphyton communities in these oligotrophic lakes. As a result, impacts of tourism are not likely to be detected by traditional measurements of open water nutrient and phytoplankton chlorophyll a concentrations. Instead, measurement of periphyton growth and/or biomass (chlorophyll a) in the littoral zone might be the most spatially and temporally relevant indicator of tourist impacts in these lakes.

In view of the increasing tourism to Fraser Island, Queensland, a tourist pressure index (TPI) was developed to assess the potential threat of tourism to 15 of the most accessible dune lakes on the island. Tourist pressure index scores indicated that the two clear lakes on the island, Lake McKenzie and Lake Birrabeen, are most threatened by tourist activities owing to their accessibility, facilities and prominence in advertising campaigns. In addition, limnological investigations of the same 15 lakes were conducted in February 1999 to determine their current trophic status and potential susceptibility to adverse impacts from tourism, particularly with reference to eutrophication. On the basis of nutrient and chlorophyll a concentrations, the two water table window lakes, Ocean Lake and Lake Wabby, were classed as mesotrophic and oligo-mesotrophic, while all of the perched dune lakes were oligotrophic. Lake McKenzie and Lake Birrabeen, the two most threatened lakes according to TPI scores, had the lowest nutrient concentrations of all of the lakes examined and, consequently, we suggest that nutrient additions might elicit rapid algal growth responses in these systems. Comparisons between current data and historical data from Arthington et al. (1990) indicate that increases in planktonic chlorophyll a concentrations were not always directly mirrored by increases in total phosphorus concentrations. We found that while chlorophyll a concentrations were significantly higher in the 1999 samples than in the 1990 samples for all lakes, total phosphorus concentrations were higher in Ocean Lake, lower in Lake Jennings and similar in lakes McKenzie, Birrabeen and Wabby.

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 differences in physical and chemical variables in the Bremer, Logan and Albert catchments in south-east Queensland. Patterns in benthic diatom assemblage structure were examined during base flow conditions and the focus was on relating the spatial hierarchical interrelationships among ultimate (i.e. catchments and geology) and proximate (i.e. flow, nutrients, light, conductivity, pH and turbidity) environmental drivers. The spatial difference observed in the benthic diatom assemblages was predominantly driven by proximate environmental drivers, which, in turn, were affected by ultimate drivers. Flow played a critical role in controlling both biofilm biomass and affecting the occurrence of diatom taxa. Nutrients and light also played roles as limiting resources structuring biofilm biomass and the relative abundance of diatoms. Diatom growth form, cell size and attachment mode can be used to create a more quantitative and predictive approach to establishing relationships between diatoms and environmental gradients.

This study: (i) established that the introduced papaya fruit fly, Bactrocera papayae Drew and Hancock, was not present in three widely separated rainforest sites; (ii) established, based on our knowledge of host use, the suitability of those sites as habitat for the papaya fruit fly; and (iii) raised the question of potential impacts of papaya fruit fly invasion of rainforests on the local and endemic fauna and flora. Data were collected between February and June 1996 from vegetation surveys, fruit fly trapping and records of insects reared from fruits collected in rainforest plots. The vegetation survey results indicate that habitat suitability for the papaya fruit fly is highly variable between the three sites sampled. No papaya fruit fly individuals were collected over the course of the study, either from traps or reared from collected fruits. Endemic tephritid species were, however, collected using both of these sampling methods. Based on analyses of potential host availability, the papaya fruit fly has the potential to become established in any of the three 1 ha plots surveyed. There is currently a lack of evidence to confirm or refute the presence of populations of the papaya fruit fly in rainforest areas. Highly focused monitoring strategies need to be employed to further assess the status of this species and the potential environmental and ecological impact(s), if any, that have escaped current detection. Ultimately, many native and endemic species of fauna and flora may be endangered by this species should populations become established in the rainforests of North Queensland.

Recreation ecology – the study of the environmental consequences of outdoor recreation/nature-based tourism activities and their effective management – is an emerging field of global importance. A primary research generalization in this field, the use–impact relationship, is commonly described as curvilinear, with proportionally more impact from initial recreation/tourism use. This finding has formed the basis of visitor management strategies in parks, wilderness, and protected areas in many parts of the world. In this paper, however, we argue that the current generalization may be an oversimplification derived from one ecological response: the response of vegetation cover in some plant communities to trampling. Use–response functions for other plant communities, wildlife, soils, and aquatic/marine systems, for example, can differ and require alternative management strategies for sustainable use. On the basis of the available literature, we propose several alternative response relationships.

Freshwater inflow events play a major role in structuring estuarine zooplankton communities. Freshwater inflow events affect zooplankton directly through advective forcing and changes in salinity, and indirectly through changes to resources by the delivery of organic carbon and nutrients that can stimulate microbial and primary production. Here, we investigate changes to estuarine zooplankton assemblage structure, density and δ13C stable isotopes during a period of highly variable freshwater inflow in the Bega River estuary, Australia. High inflows resulted in a reduction of salinity and a shift in the zooplankton assemblage structure from purely estuarine taxa towards freshwater taxa. The density of select genera of rotifers, cladocera and, in the upper estuary, copepods, increased following inflows, concurrent with increases in the concentration of dissolved organic carbon and bacterial biomass. Redundancy analysis found that environmental variables including discharge, dissolved organic carbon, salinity and bacterial biomass explained 66–73% of zooplankton variation. Stable isotope results indicated that all copepod and cladocera species tested were predominantly supported by allochthonous carbon from terrestrial sources. The present results have provided important evidence that freshwater inflows play a critical role in structuring zooplankton assemblages and supporting increased production through the delivery of allochthonous organic carbon.

Being near, on, or in water is an appealing component of many tourism and recreational pursuits. Nevertheless, the importance of freshwater ecosystems has received surprisingly little attention in the literature. This anthology aims to address the limited scholarly recognition of the role of aquatic environments in supporting tourism and recreation opportunities. To this end, Hall and Harkonen have drawn on ten diverse case studies, covering topics from cultural issues relating to lake management in New Zealand; through recreational boating activities in Finland, Poland, and the Netherlands; to historical accounts of the development of tourism around icon lakes in the United States. The challenge for the editors was to bring these diverse case studies together in a coherent framework. To do this, they divided the book into four parts: introductory context, historical dimensions and cultural values, tourist activities and perceptions, and planning and management issues. Their approach is somewhat chronological and serves to walk the reader through the historical development of lakes as focal leisure sites and the wide range of issues associated with multiple users and stakeholders. An important message is that tourism and recreation represent relatively recent uses of lake environments and, as such, opportunities are both sometimes limited and occasionally enhanced by existing infrastructure and uses of the water resource.

Freshwater flow events drive phytoplankton productivity in subtropical coastal river systems. However, few studies have the necessary temporal and spatial resolution to fully characterise the effect of events on the distribution of phytoplankton across the full river–estuary–bay continuum. The present study characterised the response of phytoplankton to high-flow events in an Australian subtropical system; and identified the primary drivers of this response. During high-flow events, the concentration of phytoplankton chlorophyll a (Chl a) initially declined in the estuary, a response primarily driven by the shortened water-residence time. In the bay, phytoplankton growth in the near-shore zone was light limited; however, nutrients stimulated phytoplankton growth on the seaward edge of the river plume. During the post-high-flow phase, the concentration of Chl a in the freshwater reaches peaked downstream, where catchment-derived nutrients accumulated. In the estuary, elevated nutrient loads stimulated phytoplankton growth upstream and downstream of the light-limited zone. In the bay, nitrogen availability declined, and Chl a declined with an increasing distance offshore. The phytoplankton response to events documented in the present study can be used to identify when and where phytoplankton in subtropical systems may be strongly influenced by changes in the magnitude of nutrient, sediment and freshwater loads associated with high-flow events which result from anthropogenic pressures within the catchment.

Many aquatic ecosystems have been severely degraded by water-resource development affecting flow regimes and biological connectivity. Freshwater fish have been particularly affected by these changes and climate change will place further stress on them. The Murray–Darling Basin (MDB), Australia, represents a highly affected aquatic system with dramatically modified flow regimes. This has impaired the health of its rivers, and potentially limited the adaptive capacity of its biota to respond to a changing climate. Here, we present our predictions of the potential impacts of climate change on 18 native fish species across their distributional ranges against the back-drop of past and continuing water-resource development (WRD). Because most of these species are found across a wide range of geographical and hydrological settings, we classified the MDB into 10 regions to account for likely variation in climate-change effects, on the basis of latitude, elevation and WRD. Cold water-tolerant species will be under greater stress than are warm water-tolerant species. In some regions, the negative impacts on exotic fish such as trout are likely to improve current conditions for native species. Because the impacts of climate change on any given species are likely to vary from region to region, regional fish assemblages will also be differentially affected. The most affected region is likely to occur in the highly disturbed Lower Murray River region, whereas the dryland rivers that are less affected in the northern MDB are likely to remain largely unchanged. Although climate change is a current and future threat to the MDB fish fauna, the continued over-regulation of water resources will place as much, if not more, stress on the remnant fish species.

Through the use of mitochondrial DNA (ATP8 gene), the prediction of intermediate genetic structuring was investigated in two species of estuarine glassfish (Ambassis marianus and Ambassis jacksoniensis) (Perciformes : Ambassidae) to determine the possibility of a generalised ‘estuarine’ genetic structure. Individuals were collected from estuaries in eastern Australia between Tin Can Bay (Queensland) in the north and Kempsey (New South Wales) in the south. Analysis of the haplotype frequencies found in this region suggested panmictic populations with star-like phylogenies with extremely high levels of genetic diversity, but with no correlation between geographic distance and genetic distance. Non-significant FST and ΦST suggested extensive dispersal among estuaries. However, Tajima’s D and Fu’s FS values suggest ‘mutation–genetic drift equilibrium’ has not been reached, and that population expansions occurring 262 000 (A. marianus) and 300 000 (A. jacksoniensis) years ago may obscure any phylogeographic structuring or isolation by distance. The finding of panmixia was contrary to the prediction of genetic structuring intermediate between that of marine fish (shallowly structured) and freshwater fish (highly structured), suggesting high dispersal capabilities in these species.