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| Cotter, A; Mesnil, Benoit; Piet, G. |
| A year-class curve is a plot of log cpue (catch per unit effort) over age for a single year class of a species (in contrast to the better known catch curve, fitted to multiple year classes at one time). When linear, the intercept and slope estimate the log cpue at age 0 and the average rate of total mortality, Z, respectively. Here, we suggest methodological refinements within a linear least squares framework. Candidate models may include a selectivity term, fleet-specific parameters, and polynomials in year to allow for gradual variations of Z. An iterative weighting method allows for differing precisions among the different fleets, and a forward (one-step ahead) validation procedure tests predicted cpue against observed values. Choice of the best... |
| Tipo: Text |
Palavras-chave: Year class curve; Plaice; North Sea; Iteratively weighted least squares; Forward validation; Fish stock assessment; Cpue; Analysis of relative residual variance. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2776.pdf |
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| Lorance, Pascal; Agnarsson, Sveinn; Damalas, Dimitrios; Des Clers, Sophie; Figueiredo, Ivone; Gil, Juan; Trenkel, Verena. |
| Stakeholder knowledge was collected through questionnaires and cognitive maps and used to summarize biological, environmental, technical, management, and socio-economic factors for several deep-water fisheries, identifying regional management issues and solutions. The questionnaires and cognitive maps revealed different technical, environmental, and management concerns in these fisheries. Dissatisfaction with management was more at an implementation than a conceptual level, because the existing management measures were mostly considered fit for purpose. Further, catch-and-effort data provided by the fishing industry were used to calculate standardized landings per unit effort. The results suggested different trends over time for three deep-water stocks... |
| Tipo: Text |
Palavras-chave: Closure; Control; Cpue; Regulation; SWOT; TAC; Technical measures. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00043/15420/13376.pdf |
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