ABSTRACT: Marine protected areas (MPAs) can potentially alter food web dynamics by increasing the density of fishes within their borders. Such increases in the density of potential competitors can cause generalist predators to contract the scope of their diets. This study investigated the effects of increased conspecific fish density on the diets of gopher rockfish Sebastes carnatus at a 35 yr old MPA in Point Lobos, California, and at 4 newly established MPAs in Año Nuevo, Point Lobos, Piedras Blancas, and Point Buchon in central California. Analyses were conducted for 707 stomachs collected from 2007 to 2009. Diets did not differ inside versus outside the old Point Lobos MPA in terms of prey richness, evenness, composition, or gopher rockfish trophic level. However, fish outside the MPA had greater levels of individual specialization. No consistent differences in these metrics were observed inside versus outside the 4 new MPAs, although prey composition and evenness did differ significantly among geographic locations. Diets at Año Nuevo, the most northern and shallow location, consisted predominantly of Cancer spp. and porcelain crabs (Porcellanidae), while diets from southern, deeper locations were dominated by brittle stars (Ophiuroidea). The case study of the old Point Lobos MPA indicates that fish feeding ecology may not change in an MPA after several decades. Differences in prey observed among geographic locations suggest variation in the community composition among central California’s new MPAs, which may influence the effect of each MPA on food web dynamics over time.