Title: Northeast Arctic haddock: investigation of uncertainty in stock assessment and improvement projection

Final project
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Supervisors: Einar Hjorleifsson
Stock assessment; projection; weight at age; maturity at age; uncertainty; spawning stock biomass; fishing mortality; reference points; bootstrap error distribution.


North-East Arctic (NEA) haddock (Melanogrammus aeglefinus Linne) is the target species for investigation. In this project, an attempt will be made to improve the methods of estimating inputs for predictions and investigate uncertainty in stock assessment and projection of haddock.

In order to improve current methods of estimating inputs for predictions, alternative methods were compared with the “averaging” methods, which are currently used in the Arctic Fisheries Working Group (AFWG). It was established empirically and supplemented by statistical tests that the “cohort” method gives the best results for predicting weight at age in stock for the youngest age groups in general and all age groups for short-term projection. The retrospective estimates and forecasts of spawning stock biomass, recruitment and fishing mortality in previous years from xADAPT and XSA are slightly different for the period 2000-2006, but working group estimates lie within the bootstrap error distribution.

Suggested algorythms based on the ADAPT framework allow an investigation of part of the uncertainty in stock assessment and projection procedures. Its prototype– program, ADAPT, can be applied as an alternative approach for estimating of population dynamics of NEA haddock.

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