Center for Marine Biodiversity and Conservation

In 2019, citizen scientists overwintered in Svalbard, a high-Arctic region experiencing extreme seasonal changes including the prolonged darkness of the polar night. During their expedition, they collected phytoplankton samples that were processed using RNA sequencing methods to investigate gene expression patterns throughout the transition into winter. This study presents a short time-series analysis of Arctic phytoplankton gene expression before and during the polar night, linking shifts in gene ontology (GO) terms across Biological Process (BP), Cellular Component (CC), and Molecular Function (MF) categories with environmental variables such as temperature, sea ice thickness, salinity, and sunlight duration. Early sampling revealed upregulation of genes related to salt stress and light response, while the coldest day exhibited widespread activation of cold response pathways and energy metabolism components. During the polar night, most gene expression declined, with selective maintenance of critical cellular functions and ion transport activities, suggesting molecular strategies that enable survival under harsh environmental extremes. This research fills key knowledge gaps about phytoplankton activity during the darkness of the polar night and demonstrates the value of citizen science in advancing polar research and engaging the public with climate-related environmental change. Further studies are needed to explore causal relationships and refine our understanding of phytoplankton responses in a rapidly changing Arctic.

Please see media created for this project here: https://drive.google.com/drive/folders/13X4aRJJ64tIDIhJUvF6DUyL55dXpGw6L?usp=share_link