2012 Natural England (NE) The Wash and North Norfolk Coast SAC - Baseline Monitoring Survey of Large Shallow Inlet and Bay

This report describes the results from an interdisciplinary field survey aimed at identifying the location, extent and condition of Annex I habitat features in the Large Shallow Inlet and Bay of The Wash and North Norfolk Coast SAC. The habitat features of interest are (i) subtidal boulder and cobble communities, and (ii) Sabellaria spinulosa reefs. Information presented is intended to serve as a baseline for future monitoring of the identified features. Acoustic sidescan data were acquired from selected areas within the broader SAC area, together with grountruthing samples representative of distinct acoustic signatures. Groundtruthing techniques included the acquisition of video and still images of the seabed and of sediment and faunal sample. Of particular interest was an area to the north of the eastern Well survey area between 10 and 47 m deep which exhibited a high density of hard and rugged features, confirmed as boulder and cobble reef on chalk bedrock by the photographic record. This area also harboured a high number of epifaunal taxa not observed in the surrounding sediments. The area has been delimited and covers approximately 470 ha. The acoustic record did not reveal the occurrence of areas of Sabellaria spinulosa reef. Infaunal samples did collect representatives of this species but in densities too small to be considered as reef. At most sites where S. spinulosa was observed, the abundance and diversity of the whole infaunal assemblage was higher than in areas where S. spinulosa was absent. Analysis of both infaunal and epifaunal assemblages revealed several distinct communities throughout the survey area.