Recolonization pattern of the polychaete Lanice conchilega on an intertidal sand flat following the severe winter of 1995/96

The recolonization process of Lanice conchilega was studied on an intertida l sand flat in the northern Wadden Sea after an intertidal population had b een wiped out during the severe winter of 1995/96. After very low recruitme nt in the first two years, the population fully recovered in the third year after its destruction. By then, the distribution pattern closely resembled the pattern before the severe winter with > 95% of all Lanice occurring be low -0.5 m mean tidal level and dominance of the density categories 6-50 in dividuals (ind) m(-2) and 51-200 ind m(-2). Lanice larvae have been observe d to attach preferentially on the tubes of adults. However, the high recrui tment in the third year was also seen in areas devoid of adult Lanice. indi cating that settlement facilitation by adults was of little importance for the recolonization process. Instead, we suggest that the observed recruitme nt pattern was a consequence of a large-scale decline in the metapopulation in the tidal basin and the onshore coastal subtidal which resulted in insu fficient larval supply onto the tidal flats and low recruitment in the firs t two years following the severe winter.