The sea/ice interface will have a constant temperature of around -20C making it a far more stable environment than that within the ice (Thomas 2004). The seawater will ensure a constant supply of nutrients; however the level of radiation is significantly reduced by the ice as it is less transparent than lake ice. The peak wavelengths that penetrate the ice are approximately 500nm (blue-green), however if there is a lot of algae present then the wavelengths will be closer to 600nm (yellow-orange) (Thomas et al. 2008).
Organisms larger than 1cm tend not to move into the ice; however research suggests that this is as much due to an intolerance of the fluctuating salinity and temperature conditions as the reduced space (Thomas 2004). An increased exposure to herbivores is countered by a large surface area at the sea/ice interface. The presence of colonial species such as Phaeocystis that grow down into the water column indicates that this is a productive microhabitat (Figure 7) (Thomas 2004).