Zilvermeeuwen vonden weer grote mossels in de Waddenzee

To be able to consume large-shelled molluscs, Herring gulls crack the shells by dropping them from the air. After 1990 no large mussels were available for Herring gulls in the Wadden Sea to use this smashing method, because of overfishing they had disappeared. Recently (mid-September 1993) the author found again smashed shells on his bike-road along the Wadden Sea dike on Texel, indicating the return of large mussels. The Herring gulls appeared to feed on clusters of loose mussels, during strong easterly wind eroded from subtidal musselbeds. Herring gulls proved to select the larger mussels: the average of smashed shells was 63.5 + 7.9 mm as compared with 52.5 + 7.5 mm in the living population. The musselbeds formely present here in the intertidal are still not recovered from the overfishing in 1990. Measures to prohibit overfishing in the future are insufficiënt.