Colne Estuary is a 2915 hectare biological and geological Site of Special Scientific Interest near Brightlingsea in Essex.

[7] Three areas in the site are managed by the Essex Wildlife Trust, Colne Point, Fingringhoe Wick and Howlands Marsh.

[2] The site has varied habitats, such as saltmarsh, mud flats, shingle spits and former gravel pits.

It also has important assemblages of invertebrates and plants, such as golden samphire and shrubby seablite.

[2] There are important geological exposures for Pleistocene studies at East Mersea; investigation is at an early stage, but they show warm climate deposits from one or more post-Anglian interglacials.