Historical State of Catalina's Ecosystem

The formation of Catalina began millions of years ago with volcanic activity on the ocean floor 22 miles off the coast of Southern California. This was followed by erosion and climate change, which created the mountains and shallow soil seen today. Originally, the land lacked terrestrial life because of its isolated location off the mainland. However plants and animals arrived eventually, most likely by chance with the help of the wind, ocean, or perhaps flight. Due to this chance arrival, the island houses many endemic species, including the Bewick's wren and the Catalina manzanita. Before human contact, Santa Catalina had an even greater biodiversity without predators and competition. [Catalina Island Conservancy]