Spatiotemporal Variations in Antarctic Protistan Communities Highlight Phytoplankton Diversity and Seasonal Dominance by a Novel Cryptophyte Lineage
Maria Hamilton, Martina Mascioni, Elisabeth Hehenberger, Charles Bachy, Charmaine Yung, Maria Vernet, Alexandra Z. Worden
Abstract
The climate-sensitive waters of the West Antarctic Peninsula (WAP), including its many fjords, are hot spots of productivity that support multiple marine mammal species. Here, we profiled protistan molecular diversity in a WAP fjord known for high productivity and found distinct spatiotemporal patterns across protistan groups. Alongside first insights to seasonal changes in community structure, we discovered a novel phytoplankton species with proliferation patterns linked to temperature shifts. We then examined evolutionary relationships between this novel lineage and other algae and their patterns in global ocean survey data. This established that Arctic and Antarctic cryptophyte communities have different species composition, with the newly identified lineage being endemic to Antarctic waters. Our research provides critical knowledge on how specific phytoplankton at the base of Antarctic food webs respond to warming, as well as information on overall diversity and community structure in this changing polar environment.