We determine spatial and temporal dynamics of chlorophyll for the Southern California Bight through analysis of 10 years of chlorophyll product derived from the Moderate Resolution Imaging Spectroradiometer on the Earth Observing System satellite Aqua (MODIS-AQUA). Concentrating on the Southern Channel Islands, we find an island mass effect associated with San Nicolas; that is, some chlorophyll originates near the island. This signal is most evident during the fall after the typical spring phytoplankton bloom subsides. In contrast, there is a relative dearth of chlorophyll around Santa Catalina Island, and its seasonal modulation corresponds to the spring bloom, implying that the dynamics are much simpler for this island. Previous studies of temperature in the inner Southern California Bight near Santa Catalina indicate that a simple one-dimensional model of temperature diffusion explains well the seasonal and depth temperature modulations found there. We couple the temperature-derived vertical diffusion coefficient with nitrate measurements from California Cooperative Oceanic Fisheries Investigations (CalCOFI) cruises to make a simple one-dimensional model relating chlorophyll, insolation, and nitrate for Santa Catalina.