In the summer of 2022, toxins produced by the brackish-water algae Prymnesium parvum killed about 1,000 metric tons of fish, snails, and mussels in the River Oder. In a study published in the journal Ecotoxicology and Environmental Safety, researchers of the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) analyzed the toxic effect of the brackish water algae Prymnesium parvum on the blood cells of various fish species in the Oder. The results revealed species–specific differences in sensitivity to the toxins.