Chrysophyte cysts reflect seasonal meteorological and limnological conditions: Evidence from sediment trap study in northeast Poland

Chrysophyte cysts are considered as good environmental indicators because of short generation times, seasonal replacement, and their high sensitivity to changes in physicochemical conditions. In our study, we explored the relationship between chrysophyte cysts and changes in meteorological conditions in two lakes located in northern Poland (Łazduny and Rzęśniki). We compared samples collected in sediment traps, results of on-site monitoring of limnological and hydrochemical variables, and meteorological data. Multiple statistical analyses showed that meteorological conditions indirectly influence cyst seasonality, through changes in the mixing regimes that determine nutrient and light availability in lakes. Even though the taxonomic structure and interannual variability of chrysophyte cysts are dependent on multiple variables, air temperature proved to be the most important meteorological variable influencing cyst assemblages. Multi-level pattern analysis showed that specific cyst types were indicative of different periods of lake physical structure, thus suggesting the potential of chrysophyte cysts in paleoclimatic studies.