Trends in mean summer chlorophyll-a concentrations in coastal waters of the Baltic Sea, the Mediterranean (mainly Italian waters) and the Greater North Sea (mainly the eastern North Sea and the Skagerrak), 1985-2003
Number of stations in brackets. Baltic Sea (incl. the Belt Sea and the Kattegat) data from: Denmark, Finland, Lithuania, Sweden and ICES. Mediterranean data from: Greece and Italy. North Sea (incl. the Skagerrak) data from: Belgium, Denmark, Norway, Sweden, UK and ICES.