Global Conservation, Trophic Relationships and Ecology of Forage Fish in Marine Ecosystems

“Forage fish” is a unique category of fishes bound together not by taxonomy or habitat, but by ecological role. They are small, abundant, schooling fishes (e.g., sand lance, anchovy, herring) that constitute a large fraction of diets in marine predators such as commercial groundfish, marine mammals and seabirds. By number, fewer than about 3% of fish in the northeast Pacific are forage fish, thus these species play a disproportionate role in the upward transfer of biomass and energy through marine food webs. Extensive fisheries have developed for forage fish, which currently account for 40% of global wild fisheries catch. This has generated concern not only for the forage species involved, but for all higher trophic level organisms that consume them.   

There are two main avenues of forage fish research: The study of fish biology and the study of fish as forage.  For both purposes, we are interested in population size and trends over time. These data are fundamental for an “Ecosystem Approach to Fisheries” management strategy but scarce for many forage species; especially those lacking commercial value. On the “fish” side, we are also interested in the biology of reproduction, recruitment and habitat use; and in the impact on populations of disease, pollution, habitat degradation, commercial fishing and marine climate. On the “forage” side, we are interested also in predation/fishing pressure, fish quality, school density, “minimum biologically acceptable limits” of forage biomass needed to support predators, and the influence of environment and fisheries on these variables.