FN Archimer Export Format PT J TI A random effects population dynamics model based on proportions-at-age and removal data for estimating total mortality BT AF TRENKEL, Verena BRAVINGTON, Mark V. LORANCE, Pascal AS 1:1;2:2;3:1; FF 1:PDG-RBE-EMH;2:;3:PDG-RBE-EMH; C1 IFREMER, F-44311 Nantes 3, France. CSIRO, Hobart, Tas, Australia. C2 IFREMER, FRANCE CSIRO, AUSTRALIA SI NANTES SE PDG-RBE-EMH IN WOS Ifremer jusqu'en 2018 copubli-int-hors-europe IF 2.32 TC 6 UR https://archimer.ifremer.fr/doc/00130/24168/22506.pdf LA English DT Article AB Catch curves are widely used to estimate total mortality for exploited marine populations. The usual population dynamics model assumes constant recruitment across years and constant total mortality. We extend this to include annual recruitment and annual total mortality. Recruitment is treated as an uncorrelated random effect, while total mortality is modelled by a random walk. Data requirements are minimal as only proportions-at-age and total catches are needed. We obtain the effective sample size for aggregated proportion-at-age data based on fitting Dirichlet-multinomial distributions to the raw sampling data. Parameter estimation is carried out by approximate likelihood. We use simulations to study parameter estimability and estimation bias of four model versions, including models treating mortality as fixed effects and misspecified models. All model versions were, in general, estimable, though for certain parameter values or replicate runs they were not. Relative estimation bias of final year total mortalities and depletion rates were lower for the proposed random effects model compared with the fixed effects version for total mortality. The model is demonstrated for the case of blue ling (Molva dypterygia) to the west of the British Isles for the period 1988 to 2011. PY 2012 PD NOV SO Canadian Journal Of Fisheries And Aquatic Sciences SN 0706-652X PU Canadian Science Publishing, Nrc Research Press VL 69 IS 11 UT 000311209800014 BP 1881 EP 1893 DI 10.1139/f2012-103 ID 24168 ER EF