Ten years of remote sensing and analyses of the Baltic Sea primary production (2010–2019)

The aim of the work is to present the possibilities of using advanced systems combining data obtained by remote sensing methods with data from other sources and bio-optical models for tracking and analyzing long-term changes in marine ecosystems. For this purpose, the 2010–2019 primary production data set provided by the SatBałtyk System, a platform that monitors the Baltic Sea based on satellite data, was used. As a result, the paper provides a quantitative description of the variability of the organic matter primary production (PP) in the Baltic Sea. In the individual months, the mean daily PP for the entire Baltic Sea, ranges from ca. 5 mgC m-2day-1 in winter (December and January) to over 700 mgC m-2day-1 in July. The overall annual PP of this basin ranges from 37 to 45 *106 tC year-1, but it is clearly noticeable that the yearly distributions of PP vary significantly from year to year over the 2010–2019 period and different regions. On the basis of the presented results for selected regions, it can be also seen that the maximum values of PP characteristic for the Baltic Sea in the summer months in the Gdańsk Basin can be observed from June to July. However, in the Bornholm Basin and the East Gotland Basin, PP does not peak until July and occasionally in August. The obtained results indicate a slight increase in the productivity of the Baltic Sea (ca. 11%) over the 10 years’ period and it also varies regionally.