 These combined processes produce new ice-free terrestrial and freshwater ecoregions, such as moraines and lagoons, which are now available for colonization by plants and animals.Heard Island has vast colonies of penguins and petrels, and large harems of land-based marine predators such as elephant seals and fur seals.Due to the very high numbers of seabirds and marine mammals on Heard Island, the area is considered a "biological hot spot".