The five Mediterranean regions have been highly favored and impacted by humans for habitation, agriculture and recreation. As a result, this ecosystem type (which only occurs on about two percent of the earth's total land area) is one of the most highly altered on the planet and contains the least undisturbed area of any ecosystem. The high degree of urbanization along the southern California coastline has resulted in the loss of significant natural areas and increasing human impacts to natural systems. Nevertheless the Mediterranean-type ecosystem of southern California has been identified as one of the world's 'hot spots' for biodiversity. Additionally, the southern California bight, an ecologically unique area of near-shore Pacific Ocean coastal habitat extending from Point Conception south and encompassing the San Diego area, provides conditions that promote high species richness and diversity.