Ichthyoplankton of the St. Lawrence Estuary: Composition, Distribution, and Abundance

Abstract

The composition, distribution, and abundance of ichthyoplankton in the St. Lawrence estuary, including adjacent portions of the Saguenay River and the northwestern Gulf of St. Lawrence, were investigated during June–July 1973, June–October 1974, and May–September 1975. The eggs and larvae of 25 species from 14 families (principally osmerids, gadids, cottids, cyclopterids, and pleuronectids) were represented. The larvae, in every year, were almost exclusively forms with demersal eggs. Larvae were consistently more abundant in the upper estuary during every sampling period due to its use as a major spawning and nursery area for several species. Both eggs and larvae were most abundant in June and July. Probable spawning times, areas, and growth of larvae are discussed for selected species. Key words: ichthyoplankton, St. Lawrence estuary, distribution, larvae, osmerids, gadids, cottids, cyclopterids, pleuronectids