Fish

Trends in abundance of Wadden Sea fish varied between ecological guilds. Fish using the Wadden Sea as a nursery area have generally decreased since the 1980s, with exception of a few species and regions. The nursery function of the Wadden Sea has greatly declined for the traditional flatfish species such as plaice, dab and sole. In contrast, two newcomers to this guild (southern species) increased, tub gurnard in all areas and sea bass in the western Wadden Sea. For other migratory species and resident species, trends varied considerably between species, regions and time periods. Most noteworthy trends are the increase of salmon and decrease of North Sea houting in Danish Wadden Sea rivers and the overall decrease of eel in all regions and gears.