A lagoon is a body of saline water that is partially separated from the adjacent sea and which keeps a proportion of saltwater at low tide.
As well as providing an important habitat for seabirds, waterfowl and marshland birds, lagoons also contain unique invertebrates and specialist plants which make this type of habitat important to the UK’s overall biodiversity.
37 acres of littoral land and saline lagoons was purchased by the Society in 1991, with assistance from English Nature (now Natural England), after almost four years of fundraising and negotiations with the land owner.
This area lies immediately South of a 33 acre area, which includes Easington Lagoon, which is owned by the Environment Agency and leased to the Society.
A further 22 acres of land to the direct South of the Lagoons was purchased in 2000. This package of land is know as Beacon Lagoons, though has previously been known as Beacon Ponds, Kilnsea Lagoons and Easington Lagoons, was initially purchased primarily because of the Society’s interest in the Little Tern colony situated there.
Beacon Lagoons contains a variety of coastal habitats including sand dunes, shingle, salt marsh, saline lagoons and pools.
The site is situated on the Holderness coast, 2km north of the Spurn peninsula and south-west of the village of Easington. It holds SSSI designation and is a potential SPA and a proposed Ramsar site because it comprises a variety of important features including:
· Its saline lagoons, which are a UK priority Annex 1 habitat under the EC ‘Habitats Directive’
· Its importance for its colony of over 1% of the British breeding population of little terns on its shingle beach and as a feeding and roosting site for important numbers of migratory birds
· Lagoons are included as a priority feature under the UK Biodiversity Action Plan
· Plants and animals which are either mainly or entirely restricted to a lagoon habitat. These species include flora and fauna protected under schedules 5 and 8 of the Wildlife and Countryside Act (1981).
The Society is responsible for the management of Beacon Lagoons, with the Spurn Bird Observatory involved in the organisation of the Little Tern Protection Scheme. A Tern warden (kindly funded by BP Exploration) is employed during the breeding season to help protect the birds against predation and from the accidental intrusion of beach users.
The water in the lagoons is strongly saline but not tidal, though storm surges may occasionally temporarily connect the lagoons with the sea. These breaches introduce marine organisms that may survive in the lagoons for several years. There is also an area of non-tidal salt marsh and some low dunes.
The main threat to the flora and fauna of the lagoons is the erosion of the beach by the North Sea and by the rise in sea levels. This ultimately threatens the site with ‘coastal squeeze’ whereby the lagoons will become tidal, eventually eliminating them altogether.
It is expected the Southern addition will eventually acquire a similar aspect to the present lagoons, which will prolong the life of the habitat and its associated flora and fauna.
Some vulnerable plant species such as Divided Sedge (Carex divisa) and Saltwort (Salsola Kali) occur here, along with Spiral Tasselweed (Ruppia cirrhosa) which is close to qualifying as a threatened species in the near future, and Sea Wormwood (Seriphidium maritimum) which is an Internationally important species.
Invertebrates characteristic of such lagoons as these are found here. Species include the mollusc Ventrosia ventrosa, the crustaceans Palaemonetes varians and Idotea chelipes, and the bryozoans Conopeum seurati. These are just a small example of the many different species in the lagoons.