An ecosystem services approach to assess managed realignment coastal policy in England

The east coast of England is under threat from climate change effects such as the sea level rise, and because of isostatic movements. In the face of these problems, the UK government is reorientating its coastal management strategy with a view to increasing its flexibility and adaptability. On the east coast this policy switch has included a series of managed realignment projects by which some sea defences are breached and the land flooded. These projects result in the restoration of salt marshes, which are a soft and more sustainable flood defence helping to dissipate wave energy. Salt marshes are considered as a benefit because they also create the opportunity for biodiversity enhancement, as well as expanded opportunities for amenity and recreation. Furthermore, carbon is stored underneath salt marshes helping to mitigate the effects of climate change. An ecosystem services approach was used to provide a framework for the cost-benefit analysis of multifunctional coastal schemes in the Blackwater estuary (Essex, UK). This method allowed a wide range of welfare impacts to be considered on a common monetary scale. The valuation of ecological services such as carbon storage, fish nurseries, and recreation and amenity can be encompassed in this method. A binary choice experiment was designed and a survey conducted in Essex, Norfolk and Suffolk (UK) to elicit the value of salt marshes created by a series of managed realignments considered as a single project in the Blackwater estuary. The final aggregate value of salt marshes was then inserted in a CBA assessing the efficiency of management realignment schemes on a catchment level such as an estuary area together with the other benefits of the project: carbon storage and fish nursery. The combined work of science and economics produced interesting results showing the economic efficiency of managed realignment projects realised at an estuary scale level.