Theoretical study of the between-haul variation of haddock selectivity in a diamond mesh cod-end

Authored by B Herrmann, FG O'Neill

Date Published: 2005

DOI: 10.1016/j.fishres.2005.01.022

Sponsors: European Union

Platforms: No platforms listed

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

We use PRESEMO, an individual-based structural model of cod-end selection, to investigate some of the mechanisms that may give rise to what has been termed `uncontrolled' between-haul variation. This is the variation in selection that can occur from haul-to-haul even though there may have been no changes to the cod-end. We demonstrate how haul-to-haul variation of the population density, the population structure and the spatial distribution of both the target and by-catch species may lead to between-haul variation of cod-end selection. We also show that for reasonable levels of variation of these parameters PRESEMO can simulate selection estimates that are consistent with and have comparable levels of between-haul variation as those obtained experimentally. (C) 2005 Elsevier B.V. All rights reserved.

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