Assessment of the effect of the spread of harmful algal blooms of the species Alexandrium pseudogonyaulax on biodiversity and human health

German coastal waters were largely spared from harmful algal blooms (HABs) in the 20th century. This has changed with the unexpected occurrence of the toxic microalgae Alexandrium pseudogonyaulax (hereafter A. pseudogonyaulax) in the North Sea and Baltic Sea in recent years and Prymnesium parvum in the Oder in the summer of 2022.

The mechanisms of the spread of these algae species and their toxic effects on the surrounding fauna are still largely unexplored. This is where the HABBAL project comes in and will characterize the algae species mentioned through foundational research.

In the first phase of funding, the harmful effects of A. pseudogonyaulax on plankton species, fish, and humans will be investigated. A possible second phase will be dedicated to the algae species Prymnesium parvum. The state of research on the toxin goniodomin A (GDA) produced by A. pseudogonyaulax and the as yet uncharacterized extracellular compounds is to be significantly expanded.

The project results are of great importance for basic research, as the extracellular compounds investigated are produced by a large number of marine algae. From a practical point of view, the structural characterization of these substances can be used to specifically investigate aspects that are hazardous to health and toxic to fish. This knowledge is essential for fisheries management and the risk assessment of algal proliferation and its effects. In the first phase, cooperation with relevant stakeholder groups will therefore be established for the second project phase. The aim is to raise public awareness of the effects of harmful algal blooms and to develop a scientific basis for measures.