Restoration of saltmarsh areas

Saltmarsh regeneration in the Eden Estuary

Saltmarshes are a rare and invaluable natural resource. Quite apart from their wildlife and aesthetic value is their role as natural buffers in protecting coastlines from erosion. In a bid to find a natural solution to the increasing problem of coastal erosion, this project has investigated the potential to regenerate saltmarsh by planting local saltmarsh species on the foreshore of the Eden Estuary.

Restored saltmarsh area on the south shore of the Eden estuary

This ‘green engineering’ approach is a cheaper and more environmentally friendly alternative to using expensive concrete blocks or gabions. It is hoped that this research will have a Scotland-wide benefit and be used to protect and enhance marshes in major firths such as the Moray, Forth and Solway.

Biodiversity, ecosystem functioning and ecosystem services of saltmarsh areas

The ‘saltmarsh regeneration’ project has demonstrated that the saltmarsh fringe in the Eden Estuary, which is a Special Area of Conservation (SAC) (Fife, Scotland), can be restored from bare mudflat with the native and locally-adapted marsh species Bolboschoenus maritimus(see ‘Saltmarsh regeneration’ project). The importance of saltmarsh system can be expressed through the ecosystem services this habitat provides such as:

immediate wildlife benefits: high tide refuge for waders; breeding sites for a range of birds; feeding ground for geese; fish spawning / nursery; marine invertebrate habitat; specialist plants; Insect / amphibian habitat;
or as part of the wider estuarine function: shoreline stability; sediment accretion; wave attenuation, flood, storm and coastal protection; nutrient/organic matter source; absorbing excess water run-off; pollution trap and water filtration; recreation, education and leisure.

In addition to counteracting the effects of habitat fragmentation / loss and sediment erosion, this management approach is also expected to enhance the diversity and functionality of the Eden Estuary ecosystem towards good ecological status (GES: Millennium Ecosystem Assessment 2005) as required by the EU Marine Strategy Framework directive. GES, however, remains to be formally assessed. This on-going restoration project thus provides the opportunity to assess the consequences of saltmarsh restoration for biodiversity and ecosystem processes and ecosystem service flows associated with the habitat. The PhD and post-doctoral research project dealing with this question are focusing on the following aspects:

Examine whether the developing community structure (in terms of species and functional diversity) and the ecosystem processes of restored marsh areas follow predictable development trajectories. Test whether these trajectories develop towards the functional capacity of natural salt marshes.
Compare ecosystem service delivery and valuation between depositional systems (mudflats) before and after saltmarsh restoration in order to improve advice for coastal management of estuarine habitats.

Natural saltmarsh on northern Eden shore

In this context, the focus of the PhD project of Kate Wade is on community analysis of the microphytobenthos, the macrofauna and the macroflora with measured ecosystem processes including sediment stability (Cohesive strength) and photosynthetic efficiency (PAM fluorimetry).

Dark incubation of mudflat: measuring community respiration

As part of her research fellowship, Claire Golléty is focusing on carbon fluxes (benthic gross primary productivity and benthic respiration) and secondary production.