How do algae living in sea ice support the Arctic food web?

Sea ice serves as a vital habitat for algae, which thrive in the porous, nutrient-rich brine pockets within the ice. In the Arctic, these algae are primarily concentrated at the bottom of the ice, where they can form extensive strands.1

This algal growth is a cornerstone of the Arctic food web for several reasons:

• Early Season Productivity: Algae within the ice develop earlier in the season than phytoplankton, providing an essential, concentrated food source when other resources are scarce.12
• Trophic Support: This primary production supports a diverse range of organisms, including zooplankton, worms, copepods, and amphipod crustaceans.12
• Higher-Level Consumption: These smaller organisms are subsequently consumed by larger species, such as polar cod, marine birds, and seals, effectively transferring energy through the ecosystem.2
• Seeding Blooms: As the ice melts, the release of algae-rich water may help seed phytoplankton blooms in the open ocean, further sustaining marine life.1