Holl-utopia - a year on

Towards the end of last year, I reported on a new wetland being created at Hollesley in Suffolk and given the name ‘Holl-utopia’ after the Dutch site Utopia Farm that inspired it.  At Hollesley Marshes there were very few breeding and passage waders and the site sustained only two pairs of breeding Lapwing annually. This fell well short of the aspirations and targets for the reserve. The issues revolved around the layout of the field system and the inability to raise water levels high enough.  The plan was to create a new 13ha coastal wetland habitat following the design of ‘Utopia’ on the island of Texel.  However, the wetland would be freshwater rather than the brackish conditions of the Dutch site, at least in the short term, due to the difficulty of constructing a sluice through the sea wall.

The key feature of Holl-utopia is that it is a shallow wetland with a high percentage of islands; some grassy, some bare, some covered in sand or gravel.  The landform creates extensive terraced areas of shallow water down to just 20cm depth, with a slightly deeper central ditch system.  Water levels will drop during the spring and summer to expose extensive muddy areas and ultimately dry out to just retain water in the deeper ditch features. The drying out is seen as an essential feature for rejuvenating the wetland in the future.   New water control structures allow water to both enter from, and drain to, the adjacent existing ditch system.  An electric anti-predator fence around the margins of the wetland keep the local foxes as mere spectators. 

The first spring saw Glossy Ibis, Spoonbill, Temminck’s Stint and Garganey recorded, along with 25 species of wader.  So how did the first breeding season shape up (with thanks to Dave Fairhurst for the data)?  Not too bad:

·          Shoveler - 1 female seen with 7 ducklings.
Lapwing - 25 nests fledged 60 young with 100% hatching success.
Ringed plover - 3 pairs fledged 9 young.
Little Ringed Plover – a male was on territory throughout May
 Avocet – 41 pairs fledged 82 young, the largest number of young fledged from a single site in       Suffolk since 1986.
 Oystercatcher – 1 pair fledged 2 young
Redshank – 10 pairs fledged 30 young.
Black headed gull – 1 pair fledged 3 young.
Shelduck – 1 pair fledged 7 young.

     

     Pics above: Hollutopia in May and July

The road to Utopia

The Wadden Sea islands in The Netherlands are remarkable for both migrant and breeding birds. Texel, at the southern end of the chain is perhaps the best known of the islands and has high levels of conservation management. In 2010 the Dutch conservation organisation Natuurmonumenten created a new nature reserve on Texel. The reserve is a 28 ha brackish lagoon behind the seawall adjacent to the Wadden Sea. Formerly a grass field in agriculture, the land was excavated to create a series of islands in a shallowly flooded lagoon. Around 84,000 m³ of soil was removed and 2,000 m³ of cockle shells brought in to cover some of the islands, which were a mix of grass, shell and mud. Seawater can enter the lagoon at high water via a sluice.

We visited Utopia in 2011 and were duly impressed. The site already supported good numbers of breeding Common (600 pairs), Arctic (60) and Little Terns (54), Avocets (73) and Ringed Plovers (10). Black-headed Gulls (200 pairs), Black-tailed Godwit, Oystercatcher, Lapwing, Redshank and Eider also breed. Spoonbills feed in the lagoon and passage and wintering waders use the lagoon for both roosting and feeding. Terns and other seabirds have a distinct advantage on Texel; the island has virtually no mammalian predators apart from a few Stoats. This was evident at our first stop; a Sandwich Tern colony of some 1200 pairs, easily accessible by ground predators but with hundreds of chicks. Even crows seemed scarce, apparently kept in check by the resident Goshawks.

This type of habitat is sadly lacking in the UK, with coastal habitats under severe pressure from human activities and sea level rise.  However, we are now well on the way to creating our own ‘Utopias’. The first, an 18 ha freshwater lagoon on the Suffolk coast will be excavated and functioning by the end of the year.  The project will excavate 16000 m³ of soil and create a mosaic of grass, bare mud and islands topped with 2000 m³ of shingle for nesting and roosting birds. The site will have an anti-predator fence around the perimeter.  More to follow but in the meanwhile...this is the Dutch Utopia.