Seasonal distribution and growth of larval herring (Clupea harengus L.) in the Georges Bank-Gulf of Maine area from 1962 to 1970

Abstract

This study reports observations made on the seasonal distribution of larval herring in the western North Atlantic from November 1962 through April 1970. It summarizes observations made during all months of the year except January and provides a more complete picture than previous studies conducted in autumn, winter, and spring of the 1950's. The seasonal distribution of larval herring from the autumn through the spring (combined with maturity, meristic and biochemical studies of adult herring in the 1960's) provides evidence of at least three discrete major spawning areas in the western North Atlantic: Georges Bank, coastal Gulf of Maine and Nova Scotia. The presence of a clockwise gyre, although it may at times break down in the winter, on Georges Bank retains the majority of larvae spawned on the Bank. The presence of a counter-clockwise current in the coastal Gulf of Maine appears to retain the larvae in these waters and the circulation off the coast of Nova Scotia results in the larvae remaining close to the spawning site or being carried into the Bay of Fundy. Larvae grow at least to a length of 50 to 55 mm (TL) before becoming post-larvae. They grow on the average of 5 mm per month from September through June.