CJS

CJS Focus on Marine & Coastal Environments

Published: 25 May 2015

logo: Marine Conservation Society

In Association with: the Marine Conservation Society


logo: WWT - wetlands for lifeSteart Marshes

Mark Simpson

 

Returning sailors used to seek out the vitamin rich leaves of scurvygrass to restore their health. Fortunately for them it’s common along our coasts. Few people these days eat it regularly (though apparently it is a peppery alternative to watercress in your salad), but one particular cluster on the Somerset coast has recently been a source of excitement.

 

English Scurvygrass at Steart Marshes (© Tim McGrath WWT)

English Scurvygrass at Steart Marshes

(© Tim McGrath WWT)

Wildfowl & Wetlands Trust (WWT) staff found fourteen English scurvygrass plants at their Steart Marshes reserve. They’re the first salt-loving plants to colonise the reserve, which was carefully crafted from low-lying land on the Steart Peninsula. Last September, the sea was allowed onto the land through a deliberate breach in the old sea wall.

 

Rising sea levels caused by climate change were putting pressure on the aging sea walls and the risk of flooding was increasing for homes, businesses and farmland on the peninsula. The Environment Agency (EA) came up with an innovative solution: manage the situation by deliberately letting the sea back onto the land in a controlled way. This meant first landscaping the whole area by digging creeks and channels that would guide the sea water as the tides ebb and flow. The spoil from the channels could be used to create new sea walls, up to a kilometre inland. The saltmarsh that would form in the new intertidal area between the old and the new sea walls would naturally sap the power from the tides before they reach the new sea walls, making them longer lasting and cheaper to maintain.

 

Resculpting the coastline is a major undertaking. If you look south from Steart village or north from Combwich, the whole landscape has changed. Inevitably the first step on such a big project was to discuss the idea with the villagers that live in and around Steart. The first community meeting was held over six years ago. There were plenty of questions but the issues were resolved through regular contact over the next two years. EA and WWT staff worked closely with the community to find out the issues that mattered to them and to understand the natural processes facing them and others living on the coast. When planning was submitted there wasn’t a single

Steart volunteers celebrate first year of work (© Alys Laver WWT)
Steart volunteers celebrate first year of work (© Alys Laver WWT)

objection and, when it came to purchasing land, every landowner sold their land freely. It’s testament to the way that group of people worked together, that many of the community are today directly involved in the day to day running of Steart Marshes, as volunteers who help maintain it and lead walks and chat to visitors.

 

The creation of Steart Marshes was made possible through the EU Birds and Habitats Directives. Rising sea levels are putting hundreds of hectares of the Severn Estuary’s rich intertidal habitat permanently underwater as it’s squeezed up against immovable sea walls. The rising water also adds pressure to those defences, which protect more than 100,000 homes and businesses in places like Cardiff, Newport, Burnham-on-Sea, Portishead, Avonmouth and Berkeley, at a value of around £5billion.

 

The directives give a mechanism to protect those homes and businesses and create new habitat for that unique mix of wildlife including 70,000 birds. Steart Marshes is compensation for what’s being gradually lost under the waves, so hard defences can be maintained up the estuary. And because the habitat was designed from scratch, it’s been designed to do much more than simply compensate.

 

  • Natural flood defence – the hundreds of metres that the sea has to cross before reaching the new sea wall reduce its impact, giving the wall a longer life and making it cheaper to

    Steart Marshes on the ground (© CIEEM)
    Steart Marshes on the ground (© CIEEM)

     maintain.

 

  • Absorbs lots of carbon – as much as 100 times more than tropical rainforest. The plants’ deep root systems deposit carbon below ground and the action of the tides prevents the carbon from oxidising while sulphates in the soils stop methane production.

 

  • Nursery for fish fry – such as sea bass, which is commercially important to the South West. Studies show that sea bass get 45% of their food from intertidal habitats in their first few months.

 

  • Wildlife – saltmarsh is one of the most biologically productive habitats on the planet, rivalling tropical rainforests. Steart Marshes is already attracting huge numbers of wading birds and wintering wildfowl as well as a wealth of other wildlife.
  • Farmland – the marshes are grazed seasonally and, in time, it’s intended that the livestock can be marketed for a premium as ‘local saltmarsh beef and lamb’. An assessment of Alkborough Flats found that any loss of arable food production was more than offset by the value of meat and wool from grazing animals.

Steart Marshes on high tide (© Sacha Dench WWT)
Steart Marshes on high tide (© Sacha Dench WWT)

 

  • That’s just the saltmarsh. Another large section of Steart Marshes is a freshwater wetland, fed by rainwater running off the surrounding hills. It stores water during heavy rains and releases it slowly having removed nutrients and silt. During winter 2014, when Somerset was flooded for months with heavy rain, there was no flooding downstream of Steart Marshes.

 

An initial estimate of the goods and services that will be provided by Steart Marshes values them at between half and £1 million per year, which is significantly more than the value of the land it replaces. It will easily pay off the cost of creating it within 40 years.

 

To watch a film about the creation of Steart Marshes, find out more and how to visit look at the website http://steart.wwt.org.uk/  

Check: Feb17


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