Reproductive Biology

Size and age at maturity have declined in recent years, most likely as a response to the fishery harvesting older and larger fish, or to a general decline in the stock biomass due to intense exploitation. A Scotian Shelf study (Beacham 1983) found that median age at maturity declined about 50% from 1959 (when age at 50% maturity was 5.4 years in males; 6.3 years in females) to 1979 (when age at 50% maturity was 2.8 years in both sexes). Median lengths at maturity declined from 20.1 to 15.4 in (51 to 39 cm) in males; 21.3 to 16.5 in (54 to 42 cm) in females. This smaller-and-younger-at-maturity trend continued between 1972 and 1995 in all zones between Georges Bank and Labrador, until presently in United States waters, maturity is reached between 1.7 and 2.3 years (median age) and 12.6 and 16.1 in (32 and 41 cm) (average length). Off the northeastern United States, the distribution of eggs indicates that important spawning occurs over the northeast peak of Georges Bank and around the perimeter of the Gulf of Maine. Reproduction peaks in winter and spring, but continues weakly throughout the year. The North Sea is a major center for reproduction in the eastern Atlantic, where spawning peaks between December and May. Eggs and larvae are pelagic, and juveniles begin descending to the bottom at sizes between 1.0 and 2.4 in (2.5 and 6.0 cm).

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