2014 RP2771 Baseline habitat mapping of the Alde, Ore and Butley SAC

The Alde, Ore and Butley Estuaries SAC is nationally and internationally important due its populations of breeding and overwintering birds. Within the Alde, Ore and Butley Estuaries there is a range of littoral sediment and rock biotopes (the latter on sea defences) that are of high diversity and species richness for estuaries in eastern England. Water quality is excellent throughout. The area is relatively natural, being largely undeveloped by man and with very limited industrial activity. The estuary contains large areas of shallow water over subtidal sediments, and extensive mudflats and saltmarshes exposed at low water. Its diverse and species-rich intertidal sand and mudflat biotopes grade naturally along many lengths of the shore into vegetated or dynamic shingle habitat, saltmarsh, grassland and reedbed. The features associated with the Alde-Ore and Butley Estuary are subtidal sediment communities including, Mid-shore areas of mixed substrata, covered by a blanket of the ephemeral algae Ulva lactuca and Enteromorpha spp. Tide swept communities present on the low shore, where the Alde joins the Butley, featuresanemones Sagartia spp., the peacock worm Sabella pavonina, the slipper limpet Crepidula fornicata and red algae. Well-sorted mud on the low shore throughout the estuary with a range of polychaetes.