Rapid sea ice loss and ocean acidification due to climate change are significantly altering the growth and nutritional value of microscopic algae, a crucial food source for larger marine animals like whales, seals, and penguins.
Recent research led by polar marine ecologist Dr. Rebecca Duncan highlights the importance of these microalgae, which thrive in sea ice. However, the thickness and coverage of sea ice have drastically reduced, with Antarctic sea ice hitting record lows for four consecutive years. Predictions suggest the Arctic Ocean could be ice-free during summer by 2050.
Dr. Duncan's research, conducted over eight years, reveals that environmental changes such as ocean acidification and rising temperatures affect microalgae composition. While increased light and warmer waters can boost fat content in certain species, there is a critical threshold where essential fats and proteins cease to accumulate, compromising food quality for marine life.
“If zooplankton fail to reproduce due to a lack of microalgae, it disrupts the entire food chain, threatening fish populations and larger predators,” Dr. Duncan explained. The loss of sea ice poses a significant risk to these fragile ecosystems, as microalgae rely on sea ice for habitat.
Dr. Duncan's findings have been published in five papers, with her latest research focusing on the differences between microalgae in land-connected sea ice and those in drifting ocean ice. This research is crucial as land-connected ice disappears faster, placing these microalgae populations under greater stress.