Orford Inshore Marine Conservation Zone (MCZ) Characterisation Report 2021 (NECR705)

This report presents the findings of a 2021 seabed survey of the Orford Inshore Marine Conservation Zone (MCZ). This site, which is designated for the protection of the broadscale habitat, ‘subtidal mixed sediment’ lies in the southern North Sea and covers an area of approximately 72 km². During the survey eighty sediment samples were collected within and outside the MCZ boundary at sixty sample sites using a mini-Hamon grab, with a further six sample stations targeted with drop-down video, although poor visibility rendered the video imagery unusable. Particle size analysis of the sediment samples indicated that most samples were subtidal mixed sediments, with varying dominance of gravel, sand and mud. Macrofaunal analysis of the samples showed that they could be categorised into four distinct infaunal assemblages, the most prevalent of which was a rich assemblage of macroinvertebrates living within soft sediments and / or on the mosaic of pebbles and cobbles. This was not well matched to existing biotopes described in the Marine Habitat Classification of Britain and Ireland (V04.05) which could be due to the relative paucity of offshore data informing the classification. Additional objectives of the study included comparing two sampling strategies, comparative evaluation of data acquired during a previous survey in 2012 and providing recommendations to inform future monitoring of the site.