California Sea Grant College Program

Using seven microsatellite markers, scientists examined the “connectivity” of red sea urchins (Strongylocentrotus franciscanus) along the West Coast of North America and found Canadian and California populations to be genetically differentiated. This is the first research project to find evidence of population structure for this species across its range. Some genetic structure was also detected among different sizes of urchins (recruits and adults) at a single site off San Diego. California populations overall, however, appear genetically the same, or “homogenized.” It should be emphasized that this apparent lack of genetic structure does not preclude the possibility of significant local recruitment within populations.