River regulation and climate change reduce river flows to major Australian floodplain wetland.

Freshwater ecosystems, including rivers and floodplain wetlands, face severe stress from unsustainable water resources development, with climate change exerting further pressure. This study compares the relative effects of river regulation and projected climate change on river flows to the semi-arid Lowbidgee Floodplain (3250 km), the largest wetland ecosystem on the heavily regulated Murrumbidgee River, Australia's second longest river, within the Murray-Darling Basin. We modelled annual natural streamflow in the lower Murrumbidgee River before major dam constructions and water diversions (1890-1927), linking river flows to runoff from the upper Murrumbidgee catchment.

Lessons learned on the feasibility of coastal wetland restoration for blue carbon and co-benefits in Australia.

Diverse types of saline coastal wetlands contribute significantly to global biodiversity, carbon stocks, and ecosystem functions. Opportunities to incentivise coastal wetland restoration from carbon markets is growing across the world. However, little is known of the economic feasibility of blue carbon restoration across different regions, or the quantities of ecological and social co-benefits that accompany restoration.

Remote sensing of water colour in small southeastern Australian waterbodies.

The colour of a waterbody may be indicative of the water quality or environmental change. Monitoring water colour can therefore be an important proxy for various waterbody processes. To this aim, satellites are increasingly being used as viable alternatives to field measurements.

Planning hydrological restoration of coastal wetlands: Key model considerations and solutions.

The hydrological restoration of coastal wetlands is an emerging approach for mitigating and adapting to climate change and enhancing ecosystem services such as improved water quality and biodiversity. This paper synthesises current knowledge on selecting appropriate modelling approaches for hydrological restoration projects. The selection of a modelling approach is based on project-specific factors, such as costs, risks, and uncertainties, and aligns with the overall project objectives.

A global assessment of estuarine tidal response to sea level rise.

Climate change induced sea level rise (SLR) is one of the greatest challenges threatening the sustainable management of estuaries worldwide. Current knowledge regarding SLR and estuarine hydrodynamics is primarily focused on individual case studies, which provides limited guidance on how different estuary typologies will respond to SLR. To expand the current knowledge, this research used an idealised hydrodynamic approach to analyse the tidal range dynamics of 25 real-world estuaries with diverse shapes and boundary conditions, providing insights into estuarine response to SLR-induced tidal variations.

A fundamental model for calculating interfacial adsorption of complex ionic and nonionic PFAS mixtures in the presence of mixed salts.

Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants that have been used extensively as firefighting agents and in a wide range of commercial applications around the world. As many of the most-common PFAS components are surfactants, they readily accumulate at interfaces, a process that can govern their environmental fate. There are thousands of PFAS compounds, and they have nearly always been used as mixtures, so it is common to find many different PFAS components present together in the environment.

Restoring estuarine ecosystems using nature-based solutions: Towards an integrated eco-engineering design guideline.

Traditional solutions to estuarine flood risk management have typically involved the implementation of static 'hard' shoreline protection structures, often at the expense of the natural landscape and the societal and ecosystem benefits they provide. In a changing climate, there is an increasing need to restore these estuarine ecosystems, and alternative measures in the form of Nature-based Solutions (NbS) are being considered. Guidance that balances ecology and engineering is required for NbS to establish as self-sustaining ecosystems.

Climate change and COVID-19: Interdisciplinary perspectives from two global crises.

The repercussions of the COVID-19 pandemic and climate change - two major current global crises - are far-reaching, the parallels between the two are striking, and their influence on one another are significant. Based on the wealth of evidence that has emerged from the scientific literature during the first two years of the pandemic, this study argues that these two global crises require holistic multisectoral mitigation strategies. Despite being different in nature, neither crisis can be effectively mitigated without considering their interdependencies.

Predicting the impact of salt mixtures on the air-water interfacial behavior of PFAS.

Salts are known to have strong impacts on environmental behavior of per- and polyfluoroalkyl substances (PFAS) including air-water interfacial adsorption. Multivalent salts impact interfacial adsorption to a greater extent than monovalent salts. Models to make a priori predictions of PFAS interfacial adsorption in the presence of multiple salts with different ionic charges are needed given the need to predict PFAS environmental fate.

Estuarine tidal range dynamics under rising sea levels.

How an estuary responds to sea level rise (SLR) is complex and depends on energy drivers (e.g., tides and river inflows), estuarine geometry (e.

Eco-hydrology as a driver for tidal restoration: Observations from a Ramsar wetland in eastern Australia.

Land reclamation projects and the installation of drainage infrastructure has impacted coastal wetlands worldwide. By altering water levels and inundation extent, these activities have changed the viable ecosystems onsite and resulted in the proliferation of freshwater species. As more than 50% of tidal wetlands have been degraded globally over the last 100 years, the importance of this issue is increasingly being recognised and tidal wetland restoration projects are underway worldwide.

Quantifying groundwater carbon dioxide and methane fluxes to an urban freshwater lake using radon measurements.

Freshwater lakes can play a significant role in greenhouse gas budgets as they can be sources or sinks of carbon to the atmosphere. However, there is limited information on groundwater discharge being a source of carbon to freshwater lakes. Here, we measure CO and CH in the largest urban freshwater lake in the metropolitan area of Sydney (Australia) and quantify groundwater discharge rates into the lake using radon (Rn, a natural groundwater tracer).

A new framework for modeling the effect of salt on interfacial adsorption of PFAS in environmental systems.

Per- and polyfluoroalkyl substances (PFAS) are surface active contaminants of great environmental concern, due to their widespread historical use and their environmental persistence. Salts are known to have a profound influence on the interfacial behaviors of all ionic surfactants, including some of the most commonly detected PFAS. This work describes a new mass-action model for predicting the interfacial behavior of surfactants as a function of salt concentration.

Sea level rise impacts on estuarine dynamics: A review.

Sea level rise (SLR) poses a hazard to ecosystems and economies in low-lying coastal and estuarine areas. To better understand the potential impacts of SLR in estuaries, a comprehensive review of existing theory, literature, and assessment tools is undertaken. In addition, several conceptual models are introduced to assist in understanding interlinked estuarine processes and their complex responses to SLR.

Coastal wetlands can be saved from sea level rise by recreating past tidal regimes.

Climate change driven Sea Level Rise (SLR) is creating a major global environmental crisis in coastal ecosystems, however, limited practical solutions are provided to prevent or mitigate the impacts. Here, we propose a novel eco-engineering solution to protect highly valued vegetated intertidal ecosystems. The new 'Tidal Replicate Method' involves the creation of a synthetic tidal regime that mimics the desired hydroperiod for intertidal wetlands.

Intertidal wetland vegetation dynamics under rising sea levels.

Intertidal wetlands have historically been in decline and are increasingly at risk due to climate change, particularly sea level rise (SLR). Different intertidal wetland communities can adapt to SLR via lateral upslope retreat to higher ground, capture and accumulation of allochthonous sediment, and/or organic accretion. In this paper, a case study is presented to assess the impact of the overall sediment accretion rate (i.

A group-contribution model for predicting the physicochemical behavior of PFAS components for understanding environmental fate.

The factors controlling per- and polyfluoroalkyl substances (PFAS) environmental fate remains the subject of considerable debate and study. As surfactants, PFAS readily partition to interfaces, a property that controls their transport and fate. A group contribution model is developed to predict the extent to which PFAS partitions to the air-water interface.

Predicting the impact of sea-level rise on intertidal rocky shores with remote sensing.

Sea-level rise is an inevitable consequence of climate change and threatens coastal ecosystems, particularly intertidal habitats that are constrained by landward development. Intertidal habitats support significant biodiversity, but also provide natural buffers from climate-threats such as increased storm events. Predicting the effects of climate scenarios on coastal ecosystems is important for understanding both the degree of habitat loss for associated ecological communities and the risk of the loss of coastal buffer zones.

Porewater exchange drives trace metal, dissolved organic carbon and total dissolved nitrogen export from a temperate mangrove wetland.

Porewater exchange is usually the least quantified process in delivering dissolved material from wetlands to coastal waters, although it has been recognised as an important pathway for the transport of trace metal, carbon and nutrient to the ocean. Here, surface water fluxes of dissolved manganese (Mn), iron (Fe), dissolved organic/inorganic carbon (DOC/DIC), total dissolved nitrogen (TDN) and phosphorous (TDP) were estimated from a temperate mangrove wetland (Kooragang Island, Newcastle, Australia). Radon (Rn, a natural groundwater tracer) was used to develop a mass balance model to quantify porewater exchange rates and evaluate the contribution of porewater-derived dissolved material to the overall wetland surface water export.