Muddying the waters? The environmental threat to the Mersey Estuary
PUBLISHED: 12:36 10 May 2011 | UPDATED: 19:20 20 February 2013
Beyond the ships and industrial chimneys lies a Mersey estuary that is surprisingly rich in wildlife, but could it soon be under threat in our race to battle climate change? Cheshire Wildlife Trust's Tom Marshall investigates
Its spring and is there a more appropriate name for this period in the calendar? With its bouncing connotations it immediately conjures up thoughts of movement; the bursting of summer flowers through the soil, bees busily carrying out their sorties from flower to flower and birds collecting moss and grass for their hedgerow des res. But if all these small movements are the harbingers of those long warming days, then the epic manoeuvres around our estuaries are perhaps the surest sign of the changing seasons.
As soon as the first swallow signals the packing away of hats and scarves at the bottom of the wardrobe, the inexorable increase in daylight sees tens of thousands of wading birds around the Dee and Mersey estuaries decide the time is right to head north to breed.
Its often easy to forget that while those iconic birds of summer the swallows and cuckoos are enjoying warmer climes in Africa, our own shores are a vital winter destination for birds which would struggle to endure a perpetual sub-zero arctic winter with little food.
Stretching its muddy arms into the Irish Sea, the Mersey estuary has a history as turbulent as its brown churning waters, but this often un-romantic image of one of the natural icons of the north west belies the vital role it plays as a refuge for wildlife.
With tributaries meandering across the Cheshire countryside making their way to the Runcorn Bridge and the industrial hubs of Liverpool and Ellesmere Port, the Mersey is an invaluable natural resource upon whose banks success and prosperity have often been built.
These same banks and wide expanses of seemingly endless mud play host to other riches however, in the shape of thousands of birds for whom the Mersey is home.
Once lambasted as a dirty, polluted corner of England, the Mersey estuary of today is one of international significance for wildlife, and one where young fish which will one day be the mainstay of our fisheries can take refuge in the shadow of industry.
This importance for wildlife and over-wintering wading and water birds in particular, has led to the area receiving numerous designations, including international Ramsar status and as a Special Protection Area. Its shores are also home to several sites of Special Scientific Interest.
Despite decades of hard work to bring the Mersey back to the thriving wildlife habitat which generations past would recognise, this iconic stretch of water is once again under threat. The potential power of its tidal flow has been targeted, as we race to reduce our carbon emissions to combat the threat of climate change, with the Government setting ambitious but necessary targets for renewable energy by 2020.
Renewable energy developments currently on the table for the Mersey include a barrage - similar to that sidelined by the Government on the Severn estuary last year after flood, cost and environmental impacts were considered too great.
This technology harnesses the power of the estuarys tidal flow by holding water behind a man-made structure which is then released at the optimum time to drive turbines set within the barrage.
At its most damaging, this type of technology can directly change the dynamic daily flows of the tides, in turn removing or altering the natural processes that create the mudflats, saltmarshes and other habitats that 70,000 birds a year such as dunlin, knot and godwits rely on across the estuary.
More flexible barrage technologies can allow for energy generation to continue while maintaining the daily tidal flow cycle. However, existing tidal barrage projects elsewhere in Europe and beyond have had mixed results and in some cases have damaged local ecosystems irreparably.
Whatever difficult choices may have to be made to meet our future energy needs, the Cheshire Wildlife Trust and other conservation bodies including the RSPB believe they should not be at the expense of wildlife habitats on our doorstep, especially those which should be receiving the highest levels of legal protection.
In recent years the focus of conservation efforts has galvanised around the creation of landscape scale projects which integrate all the elements of our countryside into self-sustaining habitats providing not just for wildlife, but for the needs of our own daily lives from water supplies to flood alleviation. Rivers and estuaries such as the Mersey are the arteries of our landscape and so are integral to this approach.
So perhaps what we need to consider before embarking on projects with such potentially significant impacts on our natural world, is whether we want to interfere with such finely tuned, balanced and dynamic environments as our estuaries - or is it too great a risk to take?
What do you think about the Mersey barrage plan? Send your views to firstname.lastname@example.org. You can learn more about the Mersey estuary by listening to an exclusive podcast, just follow the link from our website, cheshire.greatbritishlife.co.uk.
Let the bells ring out
Red may be the colour at this year's royal wedding but when it comes to setting a grand scene in our spring woodlands, there's only one colour to carpet beneath the canopy: blue. Now is the perfect time to experience a bluebell woodland, as the flowers sit alongside the fresh lime greens of early summer and rugs of moss clinging on to fallen logs.
Although most of us think of bluebells as a stalwart of the British landscape, they are now like many species, under threat from non-native invaders. The slightly larger Spanish bluebell has encroached on our native variety and the digging up of British bluebells still remains a problem.
Help is at hand however from a band of green-fingered volunteers at the Cheshire Bluebell Recovery Project; supported by funding from WREN, who are propagating our native bluebells ready for planting out in the local woodlands where they belong.
Walk the blue carpet
Where to find bluebells this May
Arley Hall Big Wood, north of Northwich
Bluebell Cottage Garden, Dutton
Capesthorne Hall, near Macclesfield
Combermere Abbey, near Whitchurch
Norton Priory, near Runcorn
Warburtons Wood nature reserve, near Kingsley between Frodsham and Northwich
Exclusive podcast, on Cheshire Wildlife Trusts blog at: www.cheshirewildlifetrust.wordpress.com
Find out more about the Bluebell Recovery Project on the Cheshire Region Biodiversity Partnership (CrBP) website at www.cheshire-biodiversity.org.uk