Vertebral Averages of Juvenile Cod, Gadus morhua, from Coastal Waters of Eastern Newfoundland and Labrador as Indicators of Stock Origin *

Vertebral averages for juvenile Atlantic cod (age-groups 0,1 and 2), collected during 1956-70 in coastal waters of Labrador and eastern Newfoundland, were used as indicators of stock origin. The averages were typically high (~54.8) for most of the samples and within the range reported for adult cod...

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Bibliographic Details
Main Authors: W. H. Lear, R. Wells
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
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Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.613.334
http://journal.nafo.int/j05/lear1.pdf
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Summary:Vertebral averages for juvenile Atlantic cod (age-groups 0,1 and 2), collected during 1956-70 in coastal waters of Labrador and eastern Newfoundland, were used as indicators of stock origin. The averages were typically high (~54.8) for most of the samples and within the range reported for adult cod of the Labrador-East Newfoundland stock which spawns offshore on the continental shelf. The consistently lower averages for the 1960 and 1961 year-classes may have resulted from delayed spawning and/or more favorable temperature conditions after spawning in these years. Occasional vertebral averages lower than 54.8 for other year-classes, particu-larly in the southern part of the surveyed area, evidently indicate intermingling with juveniles of the southern cod stock which typically have lower vertebral counts. The vertebral averages for age-groups 0 and 1 cod of the 1959 to 1969 year-classes from Notre Dame Bay were inversely correlated with mean temperatures of the 0-100 m water layer at a station in the Labrador Current otteastern Newfoundland.