In the 1850s, a sea wall was built around the part of Poole Harbour known as St Andrew's Bay to create suitable grazing land for livestock on Brownsea. Neglect of the sea wall and the wind pumps that were used to control the water levels led to the creation of the present day non-tidal saline lagoon.

It is a habitat of national and international importance for a variety of birds which use the site for nesting, feeding and roosting throughout the year.

The number and types of birds using the lagoon depend on the time of year and the state of the tide in Poole Harbour

Winter birds
In the winter it attracts large numbers of waders including: Avocet, Black- and Bar-tailed Godwit, Grey Plover, Dunlin, Redshank and Greenshank.

Sparrowhawk and Peregrine hunt across the lagoon, and Pied Wagtails, Meadow and Rock Pipits, and Kingfishers are seen regularly.

Summer migrants
April is a particularly interesting time, as the over-wintering birds depart and the summer visitors begin to arrive.

Common and Sandwich Terns, migrants from Africa, breed on artificial islands specially built for them by The Dorset Wildlife Trust. From May to July, close views of the parents feeding their young on small fish can be seen from the nature reserve hides.

Black-headed Gulls and oystercatchers also nest on the islands and around the edge of the lagoon.

Resident birds
Cormorants, oystercatchers, black backed and black headed gulls, shelducks, mallard and Canada geese can be seen on the lagoon all year round.

Grey herons and Little Egrets from the Brownsea heronry regularly roost and feed on the lagoon.

Visiting the lagoon
The lagoon is located within the nature reserve. Access is limited to certain times, but the area can be viewed at any time from the public hide by the main path leading from the quay.

©Kevin Cook / 1999