Small-Scale and Long-Term Variability in Population Dynamics of the Cockle Cerastoderma edule in a Southern North Sea Tidal Flat System

The cockle Cerastoderma edule is one of the most common macrofauna species in Wadden Sea areas North Sea. Cockle population dynamics are influenced by various abiotic and biotic factors such as temperature, food availability, inter- intraspecific competition. Cockles play an important role web Sea, for instance, large shellfish-eating birds, oystercatchers eiders, use C. blue mussel Mytilus edulis a main diet component. However, populations bird have been declining dramatically across since beginning 21st century. While there detailed monitoring programs mussels due to commercial interests, little information known about stocks long-term cockles German To fill this gap, 2005 local conservation society (“Der Mellumrat e.V.”) initiated study sample at transect per year south island Mellum, which was extended 5 more transects 2011. In addition spatial analysis, we analyzed variability dynamics. Min/max autocorrelation factor analysis (MAFA) revealed decline abundance, while no clear length trends were found. Canonical spearman correlation analyses exposed significant correlations between abundance chlorophyll a, bank area well oystercatcher eider populations. This clearly shows that urgent need comprehensive time series data analyze explain ecological changes relation environmental point out how parts web, birds affected these changes.