On the Wadden Sea tidal flats, bivalves play a key role as food for birds. It is especially in summers following severe winters that the new generation of bivalves in the Wadden Sea can be enormous. At the same time, the predators of these young bivalves, such as crabs and shrimps, are less numerous after severe winters. As the climate is getting warmer, there are fewer severe winters. As a consequence, more years now see large numbers of crabs and shrimps on the tidal flats and a decline in breeding success for bivalves. This is demonstrated by analyses of long-term data sets by the NIOZ Royal Netherlands Institute for Sea Research. The results of these analyses have been published in two articles in the scientific journal Marine Ecology Progress Series; one of them as the feature article.