Midsummer in the central Baltic. The weather is calm, but the two biggest environmental problems of the sea, overfertilization and oxygen deficiency on the ground of the deep basins, regularly spur on the rise of blue-green algal blooms (more correctly known as cyanobacterial blooms).
For years, people have been trying to understand the factors that contribute to and spur on the formation of midsummer blooms in the central Baltic. This pursuit is important, since blue-green algae is one of the few marine organisms that can survive without dissolved nitrogen, generally a no-go in the underwater world. The algae first developed this remarkable ability billions of years ago in the very beginnings of their history; a mechanism, which allowed them to transform the abundant atmospheric nitrogen into reactive bonds, called nitrogen fixation. And so, every summer thick algal blooms cover parts of the central Baltic, only for the dead remains to slowly sink towards the bottom where other bacteria breakdown the algae’s inorganic components—all while consuming a lot of oxygen.

Reasons for Research

Although we’ve been able to look at the general areal distribution of blue-green algae blooms, through satellite data and automated CO2 measurements on voluntary observing ships, the big question about the distribution of blue-green algae in the deeper water column levels remains unanswered. Neither approaches can give substantive answers: the visible top layer is only a small piece of the bloom, and when gusts of wind begin to break the algal carpet, the current methods fail to show what happens underneath the surface. So far, past attempts at on-site measurements in order to fill this knowledge gap have failed, since blooms pop up sporadically and cannot be predicted ahead of time, and research vessels are too expensive to just cross the central Baltic without a time limit, in the hopes of possibly seeing and studying a bloom. This is where marine chemist Jens Müller, his sailboat Tina V, and the Project BloomSail get involved.