Patterns in the annual weight increment for Div. 2J+3KL cod and possible prediction for stock projection
Sample body weight-at-age data for NAFO Divisions 2J+3KL cod (Gadus morhua) from research vessel surveys were examined. Considerable variability in annual weight increment was found. A general linear model containing division and age effects explained 36 % of the variance in the logarithm of annual...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
1999
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.485.3223 http://journal.nafo.int/J25/shelton.pdf |
| Summary: | Sample body weight-at-age data for NAFO Divisions 2J+3KL cod (Gadus morhua) from research vessel surveys were examined. Considerable variability in annual weight increment was found. A general linear model containing division and age effects explained 36 % of the variance in the logarithm of annual weight increment. The residuals from this model showed a temporal pattern which appears to correspond to changes in the area of the cold intermediate layer (<0°C), an indicator of the amount of cold water on the shelf. Including the area of the CIL resulted in a model which explained 41 % of the variability in weight increments. This model predicted weight increment data not included in the fitting reasonably well. Consideration is given to whether a predictive model based on this relationship could be useful in stock projections. Key words: cod, cold intermediate layer, prediction, stock projection, weight increment |
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