In the northern reaches of the ecozone where sea ice predominates, plant life is limited to species of algae and benthic organisms, such as anemones, that live on the ocean floor. Conditions further south are favourable for varieties of phytoplankton, algae, kelp and seaweeds. Coastal intertidal zones are particularly productive and provide shelter and food for a diverse community of marine animals that include such familiar residents as mussels, lobsters and crabs.