The Ross Sea is the most productive area of ocean in Antarctica, yet it is vulnerable to the effects of climate change. An increase in Southern Annular Mode wind cycles has resulted in oceanographic changes including increased sea ice and enhancement of the Ross Sea polynya. The change in sea ice affects timing of phytoplankton blooms and proportions of species of primary producers in the ecosystem, with a possible favouring of the algal species Phaeocystis antarctica. This may lead to further changes in the ecosystem, including altered biogeochemical cycling, and an altered food web, due to the fact that P. antarctica is relatively inedible compared to other primary producers. The effects of the change in phytoplankton blooms in the Ross Sea community may lead to alteration of the food web, right through to top level predators.