Polynyas are of interest from the physical and biological points of view. For example, many polynyas are sites for active sea ice growth and brine formation. The brine might affect the local water density structure and current field, and might also influence larger scale water mass modification as it is mixed and advected beyond the polynya region. The regular occurrence of polynyas makes them important as biological habitats. The associated open water can contribute in spring to a localized plankton bloom which can seed down-current areas.
Large mammals use polynyas as feeding grounds, suggesting rich biotic activity.
Inuit people have used polynyas as hunting grounds for the past 3000 years. Polynyas can form by two mechanisms. Ice forming in a region is continually removed by winds, currents or both. The heat required to balance the loss to the atmosphere and hence maintain the open water is provided by latent heat of fusion of the ice which continually forms. Oceanic heat enters the region in sufficient quantities to locally prevent ice formation.