Wetlands Australia 31: A new resource for assessing climate change in coastal wetlands: State of the science

Authors: Assoc Professor William Glamore (Water Research Laboratory, University of NSW), Dr Valentin Heimhuber (Water Research Laboratory, University of NSW), Assoc. Professor Melanie Bishop (Department of Biological Sciences, Macquarie University), Dr Gabriel Dominguez (Department of Biological Sciences, Macquarie University), Mr Duncan Rayner (Water Research Laboratory, University of NSW), Dr Peter Scanes (NSW Office of Environment and Heritage)

The science and ongoing management of coastal wetlands requires a detailed understanding of how the onsite meteorology and nearby influences are likely to change due to climate change. This article details a new resource for assessing how global and regional climate models and various datasets can be applied to coastal wetland science and risk management at the local scale.

Estuaries and tidal wetlands are highly productive and biodiverse ecosystems that are often considered the ‘nurseries of the sea’. Tidal wetlands, including mangrove forests and saltmarshes, play a critical role in the climate system as they can sequester and store large amounts of carbon dioxide. Due to their unique setting at the coastline, however, these estuarine habitats are particularly vulnerable to climate change as they are exposed to ‘double-whammy’ impacts, meaning that they are forecast to experience changes to both the upland catchment and the ocean boundary.

Estuary. Photo: Water Research Laboratory, UNSW Sydney

While projections of future climate change are useful, understanding the localised impacts of these changes on tidal wetlands and estuaries is critical for future decision making. However, downscaling the available climate change projections to a localised tidal wetland or estuary is still fraught with uncertainty. These uncertainties range from meteorological changes (first order), to variations in the flow regime (second order), to ecological aspects (third order). The potential implications of this uncertainty are further confounded when both downstream oceanic and upstream terrestrial boundary uncertainties of climate change are included.

To address this gap, the NSW Office of Environment and Heritage has teamed up with researchers from the University of NSW and Macquarie University to develop a framework for assessing climate change at the level of individual tidal wetlands. This framework is focused on coastal environments, such as estuaries and coastal wetlands, and includes a centralized database, eight report modules and an education portal, all hosted on a central website.

The eight report modules provide an illustrative summary of the relevant climate, physical and ecological science influencing estuaries and tidal wetlands via climate change. The modules are accompanied by the Eco-thresholds community database, a unique collection of physiological thresholds of estuarine species to climate change collected from over 300 literature sources. The database can be downloaded and users can add information online.

The resource will provide a roadmap for navigating the complexity of assessing climate change risks at local estuaries and tidal wetlands for researchers, government staff and consultants. The products will be useful to marine biologists studying the effect of heat stress on saltmarsh communities, government agency staff planning local management plans, high school teachers organising a class, or researchers requiring information on the impact of climate change on individual wetland species.

Mangroves. Photo: Water Research Laboratory, UNSW Sydney

Further information

• Estuaries and climate change website, including online introductory video
• Eco-Thresholds community Database of ecological thresholds for estuarine species