Mersey barrage plan barracked

Dunlin on the Mersey Estuary. Credit Paul Bunyard

December 2010. Cheshire Wildlife Trust and the Lancashire Wildlife Trust have echoed concerns raised by the RSPB over proposed plans to build a tidal barrage across the Mersey estuary to generate renewable energy.

An ‘impounding barrage' is one of two technologies identified by Peel Energy Limited in a recently published shortlist of options for generating power from the Mersey's tidal flow.

Much of the estuary is recognised as a Special Protection Area (SPA) for birds under European legislation, and is also a ‘Ramsar' site - a wetland of international importance.

Significant damage to the estuary
The Wildlife Trusts believe the construction and operation of such a barrage could cause significant damage to the estuary and have a devastating effect on the internationally-recognised populations of birds, and other wildlife.

The announcement of the proposal comes just months after the Government shelved plans for a £30 billion pound barrage on the Severn estuary in the south west, which also faced strong opposition from local and national nature conservation groups on environmental and flood-risk grounds.

Environmentally friendly option ignored
The Trusts have also expressed disappointment at the discounting of less environmentally damaging options including a Spectral Marine Energy Converter (SMEC), which would have a vastly reduced environmental impact. It is thought the long period of research and development needed to develop this technology has led to it being dropped from the list of options, as the Government strives to reach ambitious renewable energy targets by 2020.

The Trusts believe that any form of barrage across the estuary is likely to permanently alter the daily tidal systems, which provide thousands of hectares of calorie-rich mud for resident and migratory birds.

70,000 wading birds
Peak counts of species of wading birds such as dunlin have reached almost 70,000 in recent years, with redshank, black-tailed godwit and ducks including wigeon and teal also relying on the estuary as a vital feeding area.

70,000 wading birds use the Mersey Estuary.  Photo credit Paul Bunyard

Charlotte Harris, Director of Conservation at Cheshire Wildlife Trust explained how the barrage could alter the function of the estuary: "Tidal estuaries are one of the most dynamic wildlife habitats we have, and one for which the UK is internationally important. From providing refuge for young fish stocks and routes for spawning salmon to tens of thousands of migratory birds, estuaries are the lifeblood of our coasts.

"We believe that if a barrage was to be constructed over an area such as the Mersey, the daily function of the tides in replenishing this calorie-rich food source of mud may no longer operate normally - which could severely limit opportunities for many of the species that currently rely on the Mersey and similar estuaries throughout the UK."

Dave Crawshaw of Lancashire Wildlife Trust, who worked closely with the Mersey Basin Campaign in its 25 year effort to improve the estuary added: "The Mersey is synonymous with Liverpool and the north west, but its importance for wildlife is perhaps less well-known. Despite a chequered past, recent decades have seen a huge improvement in the quality of the estuary with more and more species like salmon associated with high quality estuary habitats returning to its waters.

"It is important that the impacts on all the wildlife in the estuary are fully understood and investigated, before a decision is made that could change the face of the Mersey indefinitely. The Wildlife Trusts support the use of renewable energy schemes - including tidal energy, as one way in which we can address the threat of climate change. However, such schemes should not be at the expense of wildlife habitats that have been given international protection for their importance".

The consultation documents also suggest that any barrage scheme could affect water quality, drainage, flood risk and the visual appearance of the area.

The proposals can be viewed at a number of locations across the region from 11 December to 24 January, and these locations are available via the project website at: www.merseytidalpower.co.uk