Data from: A synthesis of diets and trophic overlap of marine species in the California current

A key step toward ecosystem-based management is to better understand how
interactions within food webs affect species of commercial and
conservation importance. Here we provide comprehensive diet information
and food web analysis for major taxa within the California Current
ecosystem, including fish, marine mammals, birds, and invertebrates. We
synthesized 75 published diet studies from this ecosystem and calculated
representative diets for each species or aggregated functional group. We
assessed diet relatedness using hierarchical cluster analysis and
calculated diet overlaps based on percent similarity index (PSI). Both
analyses were performed on functional group data and also separately for
each vertebrate species. Cluster analysis identified distinct feeding
guilds and revealed both intuitive and novel diet similarities between
several species and functional groups. One intuitive example is that
functional groups preying on euphausiids, a key forage species in the
California Current, show a high amount of overlap. A novel example is the
significant diet overlap of shallow small rockfish and baleen whales
(e.g., grey whales [Eschrichtius robustus]), both of which consume large
amounts of benthic invertebrates. Functional groups were highly
significant in explaining the PSI differences between species, which
suggests that key ecological interactions will be preserved in ecosystem
models that use these functional groups. A visual representation of the
complete food web and calculation of food web statistics suggest that
there are strong similarities between the food webs of the California
Current and the Benguela Current, a similar upwelling-driven eastern
boundary current off the southwest coast of Africa.