Environmental preferences and spatiotemporal distribution of the main genera of phytoplankton present in the Bay of La Paz

Katharina Kordubel

Phytoplankton plays a fundamental role in marine food webs, impacting the functioning of entire ecosystems. Environmental variables regulate the distribution of these microorganisms and even small changes can cause shifts in phytoplankton communities. Hence, this study aimed to describe the environmental preferences, spatiotemporal distribution and diversity of the main genera of phytoplankton in the Bay of La Paz using in situ measured phytoplankton abundance and Landsat 8 derived environmental factors through Generalized Additive Models (GAMs). While using the best-fitted models for 12 selected genera, spatiotemporal predictions were made for the study area. In total, 38 genera were identified with dinoflagellates being the most abundant taxa and Chaetoceros the best-represented genus. Shifts in phytoplankton communities occurred in response to the different environmental variables and phytoplankton abundance varied spatially and seasonally. The channel linking the Ensenada, a small coastal lagoon, to the bay was identified as the most important area in terms of phytoplankton diversity. The use of Species Distribution Models (SDM) in this study has been very effective for the environmental monitoring of phytoplankton and could be considered as a suitable tool for the development and application of management strategies in coastal areas.