The long-term monitoring of settlement of sea urchins and other marine invertebrates study is part of an ongoing long-term study that is unique along the west coast.  Its value increases exponentially with time and is critically dependent on maintaining continuity and avoiding data gaps.  The data has proven useful in assessing the changes in larval output of the both harvested (red sea urchins) and non- or minimally harvested (purple sea urchins) sea urchin species over a time period that encompasses a significant period of the commercial harvesting in California. These data are used in combination with similar data collected at sites in Santa Barbara and Mendocino counties.