Sonoma Coast State Marine Conservation Area is a protected marine area on the northern California coast in the North Central Coast Study Region. It includes a three-mile stretch of shoreline between Mussel Point and Schoolhouse Beach, with boundaries set by the mean high tide line, the 3-fathom depth contour, and designated coastal points. Recreational collecting of all marine aquatic plants and some invertebrates is prohibited there, and commercial harvesting of giant kelp and bull kelp is also banned. These protections help safeguard nearshore marine habitats along the Sonoma coast.