Temporal stability of a coarse sediment community in the Central Eastern English Channel Paleovalleys

The natural variation of the benthic community of eastern Channel paleovalleys was investigated over a four-year period in the context of an aggregate extraction licence for the French side of the English Channel. Six surveys were conducted: twice a year (mid-April: pre-recruitment and the end of August: post-recruitment) in 2007, 2009 and 2010. The area showed similar features of community structural parameters, to other coarse sediment areas in the eastern English Channel. This area also presented an outstanding constancy over time. The baseline obtained allows the identification of cause-effect relationships between the impact of aggregate dredging and environmental changes and also highlights the consequences of dredging on key ecological attributes. The long-term biological recovery rate will thereby be easier to assess. The use of this baseline is discussed in terms of implications for future management of the study area.

► Quantitative sampling design in channel palleovalleys over a four-year period
► New data from coarse sand and gravel communities in the Channel
► Description of the stability in both sedimentary and biological characteristics
► Survey of a baseline period similar to benthic recovery rate after dredging
► Proposition of on a 2 mm sieving mesh for the assessment of long-term recovery