It was notified as an SSSI in 1986[1] and the estuarine reedbeds within the site are designated as a national nature reserve.

Adjacent to the site is the village of Arne, although the nearest major settlement is the town of Wareham.

It also has acid grassland, salt marsh and woodland, with reedbeds adjoining the mudflats of the harbour.

Originating in East Asia, these animals escaped from deer parks during the 1860s and have now become naturalised, living on the heath and oak woodland of the site.

[4] Arne is renowned for its natural environment, and has been featured on the BBC's Countryfile and Winterwatch programmes.