Coastal Wetland Habitats: Future Challenges and Potential Solutions

Abstract

Coastal habitats are being widely degraded and squeezed around the world due to human pressure and competition for space in the coastal zone. Rising sea levels and other aspects of climate change are and will continue to exacerbate these problems. At the same time, the value of these habitats is increasingly recognised through policies such as the EU Habitats Directive and the UK National Ecosystem Assessment, in terms of the ecosystem services they provide. As a result, management goals such as ‘no-net-loss’ targets have been implemented, requiring habitat creation or restoration projects to be included in coastal management plans.

Modelling provides a powerful approach to better understanding and addressing these threats. Simulations of future changes as part of an integrated assessment methodology can identify the key drivers of change and assess the effectiveness of potential response options. This goes beyond GIS analyses of habitat futures and begins to address relevant system dynamics and capture pertinent uncertainties including climate drivers considered in Chap. 2. Coastal simulations that aim to quantify future coastal habitats are however subject to many sources of uncertainty including incomplete scientific knowledge and understanding of environmental processes and uncertain future drivers such as the magnitude of sea-level rise.

This chapter describes two lines of investigation to address these challenges: (1) analysing the impacts of sea-level rise and climate change on coastal wetlands from the perspective of coastal management and land use and (2) analysing and managing the implications of uncertainties on wetland changes and losses. The first, conventional, method provides a deterministic set of outputs for a given input, where future impacts can be quantified for management decisions. The second, more novel, method uses outcome-driven modelling to produce probabilistic results reflecting the uncertainties. This method narrows down the impacts and possible management responses to a limited number of outcomes, including their associated likelihood values. Both approaches have their utilities and allow users to explore the potential impacts of environmental change on coastal wetlands; they are illustrated here using examples drawn from the south coast of England that are typical of northwest European coastal wetlands.

In the Tyndall Coastal Simulator, this work does not currently feed directly into the other models, as important habitats are not represented in the Norfolk case study. However, these insights are vital for managing our diverse coasts. Inclusion of habitat models with the erosion and flood models in Chaps. 7 and 8 should be a priority in future research.