Estuarine and Tidal Wetland Restoration in the United Kingdom: Policy Versus Practice

Abstract

Restoration of reclaimed marshes in the United Kingdom, referred to as managed realignment, is both a scientific and a political issue. A cross-party House of Commons report to Government stressed that provision of long-term sustainable coastal defenses must start with the premise that "coasts need space" and that government must work to increase public awareness, scientific knowledge, and political will to facilitate such a retreat from the almost sacrosanct existing shoreline. Government, in turn, has agreed with the basis of the report but is aware of conflicting interests, not least the European legislation, which has designated large areas of reclaimed marshes as Special Areas of Conservation that cannot legally be restored to their former tidal processes. Against this background, it is essential that scientific research provides convincing arguments for the necessity for managed realignment, the location, extent, and type of marshlands that need to be restored to provide sustainable flood defenses, maintain and enhance conservation status, and ensure a healthy functioning estuarine system. We examine the political and scientific issues involved, discuss model predictions and field experiments into realignment techniques, and outline the preliminary results of such experiments showing the evolution of restored intertidal wetlands in the United Kingdom.

Centuries of Human-Driven Change in Salt Marsh Ecosystems

“…Managed retreat, as this goal is known in England, reverts reclaimed land to intertidal marsh and mudflat by moving dikes or seawalls inland to create a more natural coastal flood buffer (Hazelden & Boorman 2001). In 2002, approximately 200 ha of salt marsh in England were restored in experimental tests of managed retreat (Pethick 2002). The feasibility of large-scale application of managed retreat remains in question.…”

Comparative Risk Assessment to Inform Adaptation Priorities for the Natural Environment: Observations from the First UK Climate Change Risk Assessment

“…For example, the dynamics of sea level rise in the coastal zone mean that conservation of marine habitats (e.g., saltmarsh) may require that they occupy locations that currently contain freshwater or terrestrial habitats. The existence of many inter-related factors means that ecosystem-based management cannot provide an exact science in terms of expected outcomes, and this has been exemplified by current coastal "managed realignment" schemes that have often provided surprises through resulting changes in habitats and species [95].…”

Policy considerations for managing wetlands under a changing climate

“…Catford et al 2013). For example, although some coastal wetlands may be lost to sea-level rise or peat wetlands may be lost to drying, new wetlands of the same types may spontaneously develop (Pethick 2002;Acreman et al 2009). Accommodating climate change, therefore, necessitates a greater emphasis on setting conservation targets at landscape, regional and even continental scales, such as, for example, protection of a range of wetland types, and the adoption of systematic conservation-planning principles such as those proposed by Margules and Pressey (2000) and Pressey et al (2007).…”