The spatiotemporal variability of phytoplankton phenology in the Caspian Sea (an ecoregion-based approach)

Environmental perturbations caused dramatic changes in the Caspian Sea's phytoplankton phenology, with severe consequences for ecosystem health and functioning. To better understand these changes, phenological properties of main phytoplankton blooms were quantified using satellite-derived chlorophyll-a (1998-2015). Results showed significant ecoregion-scale differences in blooms' timing, duration, magnitude and interannual variability (p < 0.05), especially in north-eastern and southern ecoregions, suggesting their high sensitivity to recent environmental changes. Given the ecological and socio-economic importance of north-eastern and southern ecoregions and the influence of temperature in bloom timing changes, this study suggests ecosystem managers and policymakers focus on future impacts of climate change on these ecoregions.