Atlantic upper circalittoral muddy sand

This habitat is relatively common and has a considerable natural range in the North East Atlantic although a patchy distribution.
Most sedimentary benthic systems on the continental shelf of Europe are believed to have been modified by fishing activities in the last 100 years, particularly by mobile demersal gears, and this habitat remains under fishing pressure. Data from a single year, 2013/2014, has revealed that than 40% of circalittoral fine sands and muddy sand were subject to trawling fishing pressure in the North Sea, with over 10% of this being interpreted a high or moderate pressure. When combining data for the North Sea and Celtic Sea more than 80% of this habitat type is considered to have been subject to such fishing pressure. Given that this is based on a single year of data, and that this type of pressure has been taking place for decades, it is likely to be an underestimate of the total area of this habitat which has been subject to such pressure. Disturbance of the substratum due to intensive fishing activities using bottom trawls or dredges can damage or modify infaunal communities, with burrowing echinoderms and bivalves being particularly vulnerable and therefore affect habitat quality.
Expert opinion is that there has been a very substantial reduction in quality of this habitat, most likely an intermediate decline affecting more than 80% of its extent although it is clear that in some locations there has also been a severe decline. The severity will depend on factors such as the intensity and frequency of disturbance. This habitat has therefore been assessed as Endangered for both the EU 28 and EU 28+ because of both past and likely continuing declines in quality.

• Biological resource use other than agriculture & forestry
• Fishing and harvesting aquatic resources
• Professional active fishing
• Benthic or demersal trawling
• Benthic dredging
• Pollution
• Marine water pollution
• Toxic chemical discharge from material dumped at sea
• Synthetic compound contamination
• Climate change
• Changes in abiotic conditions
• Water flow changes (limnic, tidal and oceanic)
• Wave exposure changes

This habitat is naturally subject to disturbance therefore likely to recover character and functionality relatively quickly if the substrate and hydrographic conditions are the same. For example meta-analysis of data on fishing impacts on muddy sand communities indicate that the recovery of biota can be measured in years.