Monitoring of surface algal blooms in the North Sea by air- and ship surveys

Since 1979, a routine monitoring programme "Tour d'Horizon Flights" has been carried out by the North Sea Directorate, in order to assess frequency and amount of oil spills in the Dutch part of the North Sea. The spatial distribution of surface algal blooms, that were spotted by the aircraft during these flights, has been recorded simultaneously. This summer 1987, a "Synoptic" programme has been initiated, in which the "by air spotting" of surface blooms is combined with direct sampling and analysing of the blooms, in order to obtain both qualitative and quantitative assessments of these surface blooms.