Feeding by a larval fish community: impact on zooplankton

We studied patterns in the diurnal fluctuations in gut fullness in 11 species of larval fish in Conception Bay, Newfoundland, Canada. From these data and empirical information on prey selection, we estimated the daily consumption rate of microzooplankton by the entire larval fish community for the period May to September in 1985 and 1986. In general, <0.1% of the available prey were consumed by larval fish per day, which is considerably less than the P/B ratio typical for temperate copepods found in this region. We conclude that larval fish are unlikely to exert significant grazing pressure on their prey and that density-dependent growth is unlikely to occur during this phase of the life cycle in fish species that use coastal Newfoundland waters as spawning or nursery areas.