In addition to the coincidence of larval fish food demand and the peak in total zooplankton mass, the size distribution of prey found in the stomachs of larval cod and haddock matches closely the size distribution of the developing zooplankton assemblage. In late winter/early spring (March-April) when the fish larvae are of small body size (2-8 mm - Stage 2), the zooplankton is dominated numerically by the small copepod Pseudocalanus spp. (1 mm prosome length), whereas later in spring (May-June) when the larvae have higher energetic demands and are capable of ingesting larger prey, most of the biomass consists of the larger Calanus finmarchicus (2.5 mm prosome length) (Davis, 1987b). By early summer (July), the larger crustaceans, including mysids, amphipods, and euphausiids, reach peak abundance coinciding with the mean prey size ingested by the late larvae and pelagic juveniles. By mid- summer (August), the zooplankton biomass has declined due to increases in predatory gelatinous species in the water column, and the juveniles seek refuge on the bottom.