The potential use of sand replenishment and artificial environments to reverse habitat decline in the Mersey Narrows SSSI New Brighton Seaforth Pools Egremont John Lamb Head of Geography The Blue Coat School Liverpool
Abstract Natural England has recently completed a study (as yet unseen) to investigate the declining state of the Mersey Narrows SSSI and propose measures to improve the habitat for wading birds, particularly turnstone. In this parallel study to the Natural England report, it is hoped that provision of new stone habitats and reinstatement of some historical sand beaches can be incorporated into long term plans for the Egremont foreshore. The options are designed to minimise costs and maximise the use of recycled materials in a sustainable manner. The present environment does not offer the optimum conditions for either wildlife or local people. This study is an attempt to find that optimum environment.
My background one of promoting the reinstatement of the historical sand beaches that existed up to 60 years ago. New Brighton Sand replenishment 1987.
Liverpool Egremont New Brighton At Egremont (south of New Brighton) the natural environment was always sand
Historic sand loss (1910 2013)
Egremont sand loss (1913 and 2013)
A declining living environment for local people.
Seacombe Egremont Seacombe and Egremont Deprivation Index Living Environment In bottom 10% of areas in England. Victorian planners constructed promenades rather than parkland.
Rock and air raid rubble turnstone feeding habitat Sandstone outcrop roosting areas. Peoples loss natures gain designated an SSSI in August 2000.
Since the construction of three groynes in 1998 offshore sandbanks have grown and smothered most of the turnstone feeding grounds. A declining living environment for local wildlife.
the turnstone habitat for which this unit was designated for is no longer there (Natural England 2012). The sandbank growth continues (2006 2010).
May 2013 -Natural England complete the Mersey Narrows Feasibility Study (as yet unseen) to investigate the decline in turnstone habitat and look at options (if any) to improve that habitat.
An opportunity for sand replenishment? Turnstone primary habitat barnacle encrusted rocks and rubble. Secondary habitat seaweed dwelling invertebrates on higher dry sand beach strandlines (Eaton 2006).
A ten point plan. To parallel the Natural England Study by proposing a new higher sand pocket beach in juxtaposition to new hard substrate feeding areas. To wherever possible use free and recycled materials that would otherwise end up dumped at sea or sent to landfill.
Where can we get free sand, rock and rubble? Peel Group s proposed redevelopment of Liverpool and Wirral Waters Recycled rock and rubble?
Recycled Sandstone bedrock? Peel Ports Liverpool 2 terminal gained a 35 million Government dredging grant (May 2013) and will excavate some sandstone bedrock.
Egremont Seaforth Recycled Sand? In 2013-14 Peel Ports will undertake 8 million tonnes of capital dredging to deepen the sea channels, 4 million tonnes of sand will fill the triangle behind a new dock wall.
Beneficial use of dredged material improving turnstone secondary habitat and roosting (mainly in winter) and community use (mainly summer).
The Ten Point Plan
1. Smaller scale sand beach.
Original proposals would have smothered the remaining strip of mussel beds (U.K BAP habitat in a Site of Special Scientific Interest).
A smaller scale sand beach avoids sensitive habitats such as mussel beds (shown in black).
The site of the proposed pocket beach. Staged sand on sand replenishment over a small area (250 metres length of coast) allows rapid recolonisation by invertebrate larvae from adjacent areas.
2. Improving the Turnstone s Secondary Feeding Habitat. Higher dry sand beaches in juxtaposition to hard rock habitats (points 4 and 5) allows turnstone to migrate up the beach on a high tide (Eaton 2006).
Turnstone feeding on tideline invertebrates.
u 3. A higher sand beach gives longer lasting roosting areas closer to new rock substrate feeding areas.
Artificial sand beach high tide roost, Kakadu beach nr Brisbane.
4. Creating New Habitat Reefs from Recycled Stone.
A new inter tidal habitat reef for turnstone made from recycled rock / rubble. New habitat reef Existing sea defence groyne
The existing small reef would be added to and extended. Large barnacle encrusted pebbles (see above) are well below the surf zone and stable in storms.
Recycled Concrete showing rapid barnacle and mussel colonisation (primary turnstone habitat).
5. Higher rock feeding areas The Creation of a Habitat Groyne from New and Recycled Rock. Existing sea defence groyne New Habitat groyne.
New Habitat groyne. New pocket beach. Habitat reef Existing sea defence groyne The juxtaposition of both turnstone habitats is the determining principle of the scheme.
6. Developing Concrete Reef Blocks and New Rock Pools.
Inspired by the Urbane Project new or recycled concrete could be modified with groove structures to encourage rapid colonisation by mussels or barnacles.
Bioblocks could be included and promoted as an ecological and educational resource.
Existing sandstone platforms could be excavated to create artificial rockpools.
7. Using Gabions to create Mussel Bed reefs. Gabions have been successfully used in commercial farming of mussels and oysters
Old mussel / oyster shells are used as a culch to attract larvae and build new habitat reefs.
Isolated rock oyster on an existing groyne at Egremont points to the potential for creating gabion reefs.
Mussels, barnacles and honeycombe reef worm growing on gabion type structure (a shopping trolley) at Seacombe opposite Liverpool. Corroding metal has a higher uptake than galvanised gabions. Further opportunities for using recycled materials?
The use of Recycled Rope from Peel Ports.
Discarded rope (shown here at Peel Ports Victoria Tower) could be recycled and incorporated in the gabions.
Barnacles prefer rough bicycle tyres, mussels prefer inner tubes (rapid colonisation of stable surfaces Egremont, Wirral, May 2013). Note wading bird footprints.
8. Creating new mussel beds using mussel spat (juvenile mussels)
In Holland, the Waddensleutels project has set up artificial mussel beds in the Wadden Sea.
9. Mussels as a Water Purifier - The Potential Involvement of the Peel Group. Peel Group s proposed Liverpool and Wirral Waters dockland schemes require clean clear water to help attract investment.
Mussels farmed on a rope lattice, filter and clean dockland waters (Smartfarm Norway).
Colonisation is rapid on the large surface area.
Some mussel mats used to purify Liverpool Waters could be towed across the river and laid on the intertidal zone at Egremont to create instant mussel bed reefs.
10. The Relocation of Sensitive Habitats. Some rock habitats in danger of smothering could be relocated a short distance upcoast.
Relocation of sensitive habitats for sand replenishment at Morcambe Bay SSSI earned a Green Heroes Award.
Small scale relocation of sensitive habitats would be necessary at Egremont to facilitate a pocket beach
If the initial pocket beach, habitat reef and groyne scheme improved net habitats, then it is hoped the idea could be extended.
Somewhere out there is the optimum environment for both wildlife and local residents? Is there the political will to find it?
The Peel Group. The initial plans (larger scale sand replenishment only) were worthy of consideration but challenging environmental and regulatory issues would have to be overcome. Practical issues involved possible migration of material, not all dredgings are golden sand but can contain a proportion of silt. Peel state they are keen to work with local communities as long as it is in an environmentally responsive and sustainable manner. They have not yet responded to the revised 10 point plan.
Natural England Report looking into the restoration of turnstone habitat at Egremont is still to be signed off by DEFRA (May 2013). Natural England state that returning sand back on to Egremont foreshore may from an SSSI perspective reduce the habitat for the interest feature (Turnstone) but acknowledges suggested mitigation and ways habitat could be created. Having circulated the revised ten point plan to both Wirral Council and Peel Ports, Natural England feel that the revised ideas will be given due consideration at the appropriate time with on-going developments of the ports. Quote Natural England will be formally consulted by the Council about any future proposals to put the sand back on to the Egremont foreshore through the planning process and this is were we will make our recommendations.
Environment Agency Will await the Natural England report prior to any comment or potential involvement.
Wirral Council Wirral Council (June 2013) have reservations regarding: a) Justification in coast defence terms b) Dredged material may be unsuitable for sand replenishment c) Concern about smothering sensitive habitats. d) any proposal would require compliance with marine licensing and planning requirements including undertaking a detailed Appropriate Assessment under the EU Habitats regulations. Talks with Wirral Borough Council are on going.
Egremont Residents As yet, no formal opinion surveys have been taken of residents views, although presentations to residents have been received very positively. There is a desire (especially amongst older residents) to reinstate the sand beaches that existed here until 60 years ago. The main concerns expressed are environmental and technical.
Conclusion Creating a higher drier sand beach at the back of part of Egremont shore could theoretically improve turnstone winter feeding / roosting habitat, but only if connected with a new hard rock reef and habitat groyne. Article 10 of the Habitats Directive emphasises the importance of ecological connectivity amongst habitat patches and species populations; supporting the Habitats Directive and Birds Directive (Naylor et al 2012). Natural England would have to agree with such a positive appraisal, only then could the scheme be examined practically, implemented and if successful extended. The European Convention on Biological Diversity commits signatories to address the underlying causes of biodiversity loss
In the U.K. Sustainability Appraisals have a stronger focus on social and economic appraisal. Sand replenishment at Colwyn Bay (May 2013) illustrates the indirect socio-economic benefits associated with coastal protection outside an SSSI. Colwyn Bay Bay June June 2012 2013
Could future sand replenishment at Egremont illustrate the indirect socio-economic benefits associated with habitat improvement within a Site of Special Scientific Interest? Somewhere out there is the optimum environment for both wildlife and local residents? Is there the political will to find it?