Less known but equally spectacular are the terrestrial conservation values of the islands and coastal areas most of which are part of the Sonoran Desert. As a serial property, Islands and Protected Areas of the Gulf of California includes representative components of all major oceanographic zones of the biogeographically diverse Gulf, thereby capturing a broad spectrum of landscapes and conservation values. The Gulf of California is notable for containing ecologically distinct bridge islands, populated across past land bridges, and oceanic islands populated by sea and air. The serial approach is an adequate reflection of the biogeographic range and diversity of the Gulf of California and its islands. The great challenges to the integrity of the marine and coastal areas mostly stem from developments outside the protected areas, most importantly excessive fisheries, tourism and coastal development.