Turning storm-damaged reserve back into magnet for birds

Walking the sea wall at Great Wigborough

Walking the sea wall at Great Wigborough

Wildlife organisations managing Suffolk coastal habitats that are among Britain’s most important and revered wildlife havens have been burdened with a tidal wave of work in the wake of last December’s damaging North Sea surge.

Newly created saltmarshes

Newly created saltmarshes

In the immediate aftermath of the event, their efforts were concentrated on clear-up operations, some of which are still continuing.

More recently the prospects for the long-term future of the affected nature reserves, many of which are as vulnerable as they are internationally significant, have occupied the conservationists’ minds.

They have long known the power of nature and the importance of working with it rather than against it on one of Britain’s most dynamic stretches of coast - and last December’s surge was the most graphic example for more than 60 years of the immense forces involved.

The nature reserve most severely affected was the Suffolk Wildlife Trust’s 64-hectare Hazlewood Marshes, near Aldeburgh. Until the surge, it was an area of wildlife-rich freshwater grazing marsh beside the Alde Estuary. The surge profoundly changed the site’s character overnight.

Flooded fields - Abbotts Hall Farm

Flooded fields - Abbotts Hall Farm

Trust chief executive Julian Roughton said: “After much discussion following the tidal surge, the trust agreed with Natural England and the Environment Agency that the nature reserve should be left as intertidal saltmarsh rather than restored - an example of unmanaged retreat, but also a pragmatic and cost-effective response to the power of nature.

“Studies show that the new intertidal area created at Hazlewood will help alleviate additional flood risk further up the estuary towards Snape - saltmarshes actually act as buffers during extreme tidal events.”

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The trust’s south-east Suffolk sites manager Andrew Excell added: “More than a quarter of the Hazlewood reserve is permanently under salt water now, with most of the remainder covered by high tides.

“If it’s going to stay as saltmarsh and mudflats the area is in a far from ideal condition. With funding from Natural England and using the results of the aerial survey that was carried out with the support of the Touching the Tide Heritage Lottery Fund Landscape Partnership, we will now be focusing on improving the habitat for breeding birds by remodelling the landscape to create more shallow feeding areas and more raised nesting sites for species such as avocet.

Aaron Howe, South Suffolk Sites Manager for the RSPB on Havergate Island, Near Orfor

Aaron Howe, South Suffolk Sites Manager for the RSPB on Havergate Island, Near Orfor d

“Recent monitoring shows that sediment being brought in and deposited by the tide, is building up and saltmarsh plants are starting to grow already.

“Plenty of invertebrate food is being washed in, as can be seen by the number of birds feeding at the site - last week we had over 550 black tailed godwits. Redshank, avocet and lapwing are also benefitting.

“Over the coming months we will be removing old fencing and other debris resulting from the floods, improving access, creating a new viewing platform and installing new information boards. Next year we expect the reserve to develop into a real gem - a magnet for breeding birds and a great experience for visitors.

“With the right management, the ‘new’ tidal Hazlewood Marshes will be a different kind of nature reserve, but just as important to Suffolk’s amazing coastal wildlife as the old one was.”

The bizarrely twisted visitor centre and adjacent birdwatching hide on the RSPB’s Havergate Island nature reserve is testament to the brutal, unstoppable forces unleashed during last December’s North sea surge.

Damaged beyond repair, the buildings were lifted from their foundations and contorted into ruins as if they had been mere matchboxes.

Luckily, recently completed lagoon works on the island, paid for through the EU LIFE+ programme, were not damaged and sluices installed as part of the project helped to drain the site following the flood.

Aaron Howe, the RSPB’s senior site manager at Havergate, recalled: “The most extensive damage was on Doveys lagoon at the southern end of the island where the steep higher walls were overtopped and the overtopping caused the internal toe to be washed out and half of the walls width scoured out.”

However, he added: “We were lucky in that Havergate has a predominantly saline environment, consisting of saltmarsh and saline lagoons. This means that the long-term impact on the wildlife of the site is much less than it would have been if this was a freshwater habitat. It can cope with this kind of flooding as long as it is not in the breeding season.

“The biggest impact was probably on the island’s hare population, which was reduced to a handful of individuals after the flood, but has recovered well after a good breeding season this year, thanks to the mild conditions in spring and autumn.”

A few miles to the north, at the RSPB’s famous Minsmere nature reserve, saltwater incursion damaged an area of reedbed but the affected area was small and isolated.

An RSPB spokesman said protecting coastal freshwater habitats presented “big challenges” in the face of events such as last year’s surge – events which were becoming more regular. “Some of the country’s most valuable freshwater habitats are located along the Suffolk and Norfolk coasts, where threatened breeding birds like bitterns, avocets and lapwings have some of the strongholds,” he said.

“The RSPB has not been idle on this front and has adopted a strategic approach to protecting important habitats which seeks to work with the changing coastal environment rather than against it. The best example of this is at Titchwell Marsh on the north Norfolk coast, where work to realign the reserve’s seawalls to adapt and protect the precious wetland within completed in 2011- and not a moment too soon, as without it the wetland would undoubtedly have been inundated by the sea.

“Working with natural coastal environments and habitats like mudflats, saline lagoons and saltmarshes offers a very attractive solution to managing coastal flooding. These features have the benefit of being cost-effective - actually generating revenue through tourism because of the wildlife they attract, absorbing large volumes of water in flooding events and adapting to sea level rises.

“Even before last year’s floods, conservation organisations and government agencies had identified the threats that coastal change and the encroaching sea posed to these protected sites and started taking action to pre-empt the day when it became impossible to protect them.

“Rather than burying heads in the sand dunes and hoping the sea could be kept at bay, the RSPB has invested heavily in the creation and extension of inland freshwater habitats, such as at Lakenheath Fen in Suffolk and Ouse Fen in Cambridgeshire.”

Managed realignment – the intentional, controlled, breaching of sea walls – may have its critics but the concept’s supporters point to its proven financial, social and wildlife benefits.

The resultant sea water flooding of areas previously protected by the walls creates new marshland habitats for a wealth of species, dissipates the power of surge tides and diverts flood water that could otherwise threaten coastal and estuarine communities. It also means that public money does not have to be spent on the expensive upkeep of the walls that have been breached.

One of the early pioneers of managed realignment remains a passionate supporter and says that, in the right location, it could prove invaluable for future flood protection in East Anglia. Now an independent wetland consultant, Mark Dixon, of West Mersea, played a key role in the design of the highly acclaimed Abbotts Hall Farm managed realignment at Great Wigborough, near Colchester, 12 years ago.

The 700 acre wildlife-friendly farm beside the Blackwater Estuary is owned by the Essex Wildlife Trust, which has its headquarters on the site. The trust worked closely with the Environment Agency, for whom Mr Dixon then worked, after it bought the farm in 1999. Sea walls needed repair but the trust and the agency sought a new approach to coastal defence. After two years of study and research, five breaches were made in 2002 and the first big tide flooded about 120 acres of low-lying land behind the sea wall. Now the flooded area is a haven for wading birds and many other forms of wildlife.

“In the right places I would say managed realignment offer many benefits,” said Mr Dixon, who has more recently worked on Europe’s biggest managed realignment project at Medmerry, West Sussex. “If a sea wall has become too expensive to maintain, bearing in mind the money comes from the public purse and is spent for the benefit of very few people, there should be realignment with a reasonable compensation package for the landowner.

“In terms of flood risk, energy can rattle up an estuary, all the way up to places such as Snape or Maldon or wherever, but the realignment area can avert that energy sideways so there is a direct benefit in major storms. It also means that you do not have to spend money on that land any more - you can spend it in areas where it is to the benefit of more people.”

In addition to the financial and social benefits, he said, there were many environmental advantages. The newly created wetland areas would be beneficial to birdlife and invertebrates – and an underestimated aspect was that such areas offered “hugely important” benefits as fish fry nurseries.

At Abbotts Hall Farm, the trust proudly points to the area’s large numbers of young bass, herring and 14 other fish species that feed in the creeks within the marshes.

“There is some research that suggests declines in some fish stocks are as much to do with the destruction of nursery areas as overfishing,” added Mr Dixon. “Also, these areas soak up pollutants. Mudflats at realignments have been found to be twice as good as rainforests in soaking up carbon.