Although landing on the islands is prohibited, the waters around them are still a frequent destination for divers, snorkelers and fishermen. Ecology Flora Plant communities The topography, soil, and human impact each have effects on the vegetation of the islands, creating varying characteristics on each island. However, the vegetation of the Coronado Islands is mostly dominated by maritime succulent scrub, a plant community within the sage scrub ecosystem of North America, characterized a predominance of succulent plants and a dependence on ocean fog as a consistent source of moisture. It forms a transitional zone between the Mediterranean ecosystems of the California Floristic Province and the subtropical deserts of western North America. It includes a number of species characteristic of the coastal sage scrub, but is complemented by a wide assemblage of endemic species, giving it the greatest species richness of any of the sage scrub communities. Some taxa representative of this environment include succulents such as liveforevers (Dudleya spp.), and cacti like the coastal cholla (Cylindropuntia prolifera), coastal prickly pear (Opuntia littoralis) and the golden-spined cereus (Bergerocactus emoryi). This habitat is most typical of northwestern Baja California, ranging from the town of San Vicente to the vicinity of Punta San Carlos, a coastal swathe of about . It occurs farther north, but in a more fragmented pattern, occupying the fringe coastal bluffs and mesas up to the Mexico–United States border and sparsely north to Torrey Pines State Natural Reserve in San Diego County, California. It is also present on the other offshore islands of the region, including Isla San Martin and Todos Santos Island, but also portions of San Clemente and Santa Catalina Island in the southern Channel Islands of California. On South Island the area at the extreme northern end, near the lighthouse, has diverging vegetation. Here, the vegetation takes on an aspect of coastal sage scrub. Coastal sage scrub consists of low-growing, aromatic and more herbaceous plants with soft, drought-deciduous leaves as opposed to those of the succulent scrub. The dominant plants found in this area include California sagebrush (Artemisia californica), lemonade berry (Rhus integrifolia), California buckwheat (Eriogonum fasciculatum) and toyon (Heteromeles arbutifolia). This area is the only location on South Island where Eriogonum fasciculatum, Heteromeles arbutifolia, and broom baccharis (Baccharis sarothroides) grow. Also present on the north end, but on the east slope, is the endemic Galium coronadoense and Galium angustifolium.Non-native plants such as crystalline ice plant