Estimating spawning stock biomass in 2J3KL cod using a cohort maturation model and variable sex ratio / M. Joanne Miller.: Fs70-1/2000-110E-PDF
Estimates of proportion mature at age and age at 50% maturity were produced for Div. 2J3KL cod using a cohort maturation model. For 2J3KL combined, age at 50% maturity has been declining for both males and females since the earliest cohorts that could be estimated. Differences between estimates of maturity from this method and the annual method are generally small but variable. Spawning stock biomass (SSB) produced using the two methods show similar trends with a maximum difference of 246,000 t and 26%. Estimates of proportion female at age were found to increase with age and were variable across time. Comparison of SSB using fixed and variable proportions female showed that the two methods produced similar trends with the variable sex ratio method generally producing higher estimates with a maximum difference of 31,000 t or 9%. When SSB produced using annual estimates of maturity and a fixed sex ratio was compared to SSB produced using cohort estimates of maturity and a variable sex ratio the maximum difference was 95,000 t and 27%.
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| Department/Agency | Canada. Department of Fisheries and Oceans. Canada. Canadian Stock Assessment Secretariat. |
|---|---|
| Title | Estimating spawning stock biomass in 2J3KL cod using a cohort maturation model and variable sex ratio / M. Joanne Miller. |
| Series title | Canadian Stock Assessment Secretariat research document, 1480-4883 ; 2000/110 |
| Publication type | Series - View Master Record |
| Language | [English] |
| Format | Electronic |
| Electronic document | |
| Note(s) | Includes bibliographic references (p. 6-7). |
| Publishing information | Ottawa : Fisheries and Oceans Canada, 2000. |
| Author / Contributor | Morgan, M. Joanne (Mary Joanne), 1961- |
| Description | 17 p. : fig., graphs. |
| Catalogue number |
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| Subject terms | Fisheries resources Salt water fish Fishing area Fisheries management |