Forecasting Yields of Two-Sea-Winter Atlantic Salmon ( Salmo salar ) from Icelandic Rivers
To forecast yields of two-sea-winter Atlantic salmon (Salmo salar) from 15 Icelandic rivers, I developed predictive regression equations based on yields of grilse of the same smolt class harvested in the previous year. The relationships were positive and significant (P < 0.05) for all rivers....
| Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
|---|---|
| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1984
|
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/f84-147 http://www.nrcresearchpress.com/doi/pdf/10.1139/f84-147 |
| Summary: | To forecast yields of two-sea-winter Atlantic salmon (Salmo salar) from 15 Icelandic rivers, I developed predictive regression equations based on yields of grilse of the same smolt class harvested in the previous year. The relationships were positive and significant (P < 0.05) for all rivers. The logarithm of grilse catch explained 25–85% of the variation in logarithm of two-sea-winter salmon catch the following year. Inasmuch as statistical tests for linearity between the variables were difficult to interpret and showed conflicting conclusions, I consider them inadequate for assessing whether density dependence occurs between grilse and two-sea-winter salmon. Linear or near linear relationships, which imply no density dependence, appear to occur between log grilse and log two-sea-winter salmon yields. The critical period determining run size from a given escapement thus occurs either during the freshwater rearing phase or during the first year the salmon are at sea. |
|---|