Pevensey Levels is SSSI land with many unique specimens to the area. It houses one of the few habitats of the Fen Raft spider. 47 acres of the land are owned by the Sussex Trust for Nature Conservation as a nature reserve. Access to the reserve is by permit available on application to Woods Mill, Henfield, West Sussex, BN5 9SD.
The ancient drainage dykes which cross the area remain full all year round and support a wealth of water plants. Floating carpets of thousands of tiny Duckweed cover the ditches in which other aquatic plants such as Water Soldier, Arrowhead, Pondweed, Rushes and Reeds thrive. A few very rare plants such as the Water Violet and the Flowering Rush can be seen on the marshes. Newts, frogs and toads breed in the ditches. Many birds of prey can be seen hovering over the marshes living off the abundance of mice, voles and shrew. The Heron breeds over the marshes and can be seen along with duck, geese, swan and Snipe, Lapwing and Redshank.
The beach and shoreline host a range of seabirds from Gulls to Cormorants, Curlews, Guillemots and Turnstones. There are many insects which have made this area their home including many species of grassland butterflies, damselflies and dragonflies. The hedges which criss/cross the area are a host to many native shrubs and plants.