Intertidal Monitoring of the Mawddach Estuary Biotopes in Pen Llyn a'r Sarnau Special Areas of Conservation (SACs) 2004 dataset https://portal.medin.org.uk/portal/start.php?tpc=007_NRW_DS102009 The Habitats Directive establishes that the management of Special Areas of Conservation (SACs) should aim to achieve the favourable conservation status of habitat and species features listed within its Annex I and Annex II. For SACs in Wales, the Countryside Council for Wales (CCW) is therefore required to report on a regular basis on whether features are in favourable conservation status. The Afon Mawddach (Mawddach estuary) is a small, drying, bar-built estuary, and it is one of the best examples of its type in the UK. With its mountainous catchment area, it has some of the lowest nutrient inputs of any estuary in Wales. For this reason, the Mawddach estuary has been included in the Pen Llyn a'r Sarnau marine Special Area of Conservation (SAC). The Mawddach estuary is predominantly a sandy/sandy mud estuary and contains communities characteristic of these conditions. The Institute of Estuarine and Coastal Studies (IECS) as part of the 2004 intertidal monitoring programme undertook a Phase 1 biotope survey of the Mawddach estuary following previous monitoring at the site. Specific aims of the survey included to carry out a Phase 1 biotope survey along predefined transects noting infaunal species and sediment characteristics, to digitally record photographic evidence along each transect and to assign biotopes to each of the sampling locations. This in turn would allow information to be provided on conservation objectives of the Pen Llyn a'r Sarnau SAC estuary feature. 20081231