Sea Ice Dynamics and Planktonic Adaptations: A Study of Terra Nova Bay’s Mesozooplanktonic Community during the Austral Summer

Phytoplankton and zooplanktonic communities form the base of the Antarctic food web. This study examines the evolution of the mesozooplanktonic system in Terra Nova Bay during the austral summer (December–February), focusing on the impact of sea ice dynamics and the resulting phytoplankton blooms. Terra Nova Bay (Ross Sea) offers a valuable context given its high productivity and ecological variability. Using a diachronic approach, we analyzed data spanning twelve years to understand how the system’s structure and functionality change over time. A novel key metric, Days since Sea Ice Melting, was employed to track shifts in phytoplankton community development and trophic dynamics. The results indicate that the system enters the summer season increasing primary productivity and creating the support for the development of a more complex and organized system during the season. The phytoplankton bloom recorded during mid-season, coped by an increase in biomass, is followed by the establishment of a well-organized grazing system. A secondary phytoplankton bloom is observed towards the end of the summer, but it does not significantly affect mesozooplankton communities. Overall, this study highlights the dynamic nature of Terra Nova Bay’s mesozooplanktonic community and evaluates the influence of climate change on Antarctic marine ecosystems.