Zonation of Nearshore Mysids

Between the shore and 17 m depth, over sand bottom on the open coast of southern California, five species of hypopelagic mysids and four species of benthic mysids occurred in bathymetric zones roughly parallel with the shore. The possible causes and function of zonation of the numerically dominant pelagic species were examined. The information suggests that the zonation may have developed as observed mainly in response to the pattern of availability of food that was imposed by the nearshore circulation system, and that competitive exclusion of other pelagic specied occurred. The zonation may provide a situation wherein population control can be effected by changes in reproduction rate.