FN Archimer Export Format PT J TI Assessing the impact of discretisation assumptions in a length-structured population growth model BT AF DROUINEAU, Hilaire MAHEVAS, Stephanie BERTIGNAC, Michel FERTIN, A AS 1:1;2:1;3:2;4:3; FF 1:PDG-DOP-DCN-EMH;2:PDG-DOP-DCN-EMH;3:PDG-DOP-DCB-STH-LBH;4:; C1 IFREMER, Dept EMH, F-44311 Nantes 3, France. IFREMER, Ctr Brest, Lab Biol Halieut, STH, F-29280 Plouzane, France. Univ Tours, IRBI, UMR CNRS 6035, F-37200 Tours, France. C2 IFREMER, FRANCE IFREMER, FRANCE UNIV TOURS, FRANCE SI NANTES BREST SE PDG-DOP-DCN-EMH PDG-DOP-DCB-STH-LBH IN WOS Ifremer jusqu'en 2018 copubli-france copubli-univ-france IF 1.434 TC 13 UR https://archimer.ifremer.fr/doc/2008/publication-4301.pdf LA English DT Article DE ;Sensitivity analysis;Discrete model;Growth;Length structured model AB Most of the traditional assessment models are age-structured. However, many biological and exploitation processes are more length-dependent than age-dependent, and the required length-age conversion of available data is often not reliable. Consequently, length-structured or age-length structured models have undergone considerable development in recent years. The growth transition matrix used to model the mean growth and growth variability of the population, is of primary importance in a length-structured matrix model. Building this growth transition matrix is not trivial and it is necessary to assess the impact that various assumptions may have to identify robust model structures. In this study, we assess the effects of (1) time and length discretisation, (2) the distribution of individuals within length classes and (3) the statistical distribution used to describe growth variability, by fitting a growth matrix model to individual quasi-continuous simulated growth data. The study quantitatively demonstrates that the choice of the time step and of length class width is the key point when building a length-structured population growth model. The use of a gamma distribution for the growth increments and/or a uniform distribution of individuals within length classes were found to make the model more robust. (C) 2007 Elsevier B.V. All rights reserved. PY 2008 PD JUL SO Fisheries Research SN 0165-7836 PU Elsevier VL 91 IS 2-3 UT 000256578300006 BP 160 EP 167 DI 10.1016/j.fishres.2007.11.017 ID 4301 ER EF