Salt marsh – the second most productive & valuable ecosystem in the world after coral reefs

Before the Solar Power Station was proposed, the Environment Agency had planned to return Graveney Marshes to salt marsh within 5-10 years. They highlighted Cleve Hill as “one of the top-ranking sites for managed realignment in the area”, expected to yield around 38% of its 535 ha intertidal habitat requirements. Whilst they can delay this to a later stage, they cannot do this indefinitely and requested a 40 year time limit to be placed on the development.

Managed realignment is an intertidal habitat creation technique, using breaches (holes) in the sea wall to allow the sea in to recreate intertidal habitats. Working with nature, it is a pioneering form of flood defence and creates new habitat for wildlife. 

In 2015, the RSPB deliberately breached the sea defences on Wallasea Island, off the Essex coast, transforming 280 ha of arable fields into salt marsh and mud flats. Every time the tide comes in and goes out, new silt / mud is trapped in the salt marsh vegetation which, over time, raises the ground level.  With rising sea levels it is thought salt marshes will continue to increase in height, keeping up with the rising sea level and providing a natural flood defence to save many coastal communities. Importantly, growing salt marsh is also the best possible habitat to combat rising greenhouse emissions. As it traps silt it locks away 50 times more atmospheric carbon than a forest of the same size, and is the second most productive and valuable ecosystem in the world after coral reefs.

Ocean Autopsy: The Secret Story (BBC4 8 June 2020) featured an example of this technique. In 2015, the RSPB deliberately breached the sea defences on Wallasea Island, off the Essex coast, transforming 280 ha of arable fields into salt marsh and mud flats, and creating new habitat for wildlife.  Since the realignment, the reserve has become a major new home for breeding birds with almost 150 pairs of avocets now living there year round, more than any other site in the UK.

Working with nature means we don’t have to protect ourselves against sea level rise by using large amounts of concrete to reinforce sea walls. 

Scroby Sands Wind Farm, Norfolk

Wind farms have helped UK reduce its carbon footprint by almost 40% since 1990 and now produce 20% of Britain’s electricity.  The aim is to increase that to 33% by 2030 – erection of additional 5k turbines. 

Ocean Autopsy: The Secret Story (BBC4 8 June 2020) featured Scroby Sands Wind Farm, off the coast of Norfolk.  Technology has been developed to shield the noise of construction which previously had a detrimental impact on wildlife. The programme demonstrated that, once established, the turbine structure provides home for animals by creating a ‘marine park’, an artificial reef allowing life to get a grip on what was previously just a sandy environment.  Seal populations have also increased as they feed on the fish and other marine organisms living around the turbines.  The British and Irish waters are now home to 50% of the Earth’s grey seal population, a species which is endangered in other parts of the world. 

Evidence has shown that turbines are positively changing the ecology of the area by bringing wildlife back to the area.  Despite this, on 1 June 2020, the Secretary of State refused the Development Consent Order for a 340 MW extension to the existing Thanet Offshore Wind Farm.