Publications by L Kell
NEA Mackerel Stock Recruitment Relationships
See https://rdrr.io/rforge/FLCore/man/SRModels.html library(FLCore) library(FLBRP) library(ggplotFL) library(ggplot2) library(plyr) library(dplyr) Introduction References Summary If you fit a Beverton and Holt stock recruitment relationship there is a strong residual pattern, i.e. low recruitment up to 2000, after which recruitment increases. T...
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Evaluation of reference points
Reference Points Productivity Stock and recruitment Projection References The aim of this vignette is to demonstrate how to evaluate the factors that affect productivity and hence reference points using Western Mediterranean red mullet as an example. To do this we devlop a simulation model (i.e. an Operating Model) conditioned on the latest asse...
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CAPAM Diagnostic Workshop: Hiundcasting
Model Diagnostics in Integrated Stock Assessments Hindcasting Laurence Kell, Henning Winker, Massimiliano Cardinale, Rishi Sharma, Iago Mosqueira, Toshihide Kitakado Jan 31-Feb 3 2022 What diagnostics should be defaults in assessment reports? Cookbook Carvalho et al. (2021) ICES Working Groups assess multiple stocks using a single model per...
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Allee Effects
Outline Fit a sigmoidal Beverton and Holt stock recruitment relationship to North Sea plaice Project for 2000 onwards, for high F and different depensation parameters, i.e. 0.5, 1, 2 Compare equilibrium curves, i.e. \(MSY\) targets and limit reference points Summary If there is an Allee effect then for the same high F, the stock will be more ...
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Conditioning simulation models on life history relationships: Length Based Indicators and Methods
Introduction Installation Quick Start Life History Relationships Operating Model Length Based Indicators Length Based Methods Reciever Operating Characteristics Management Strategy Evaluation More information References Introduction Data Life history parameters Simulation Condition Operating Models on life history theory Use a sawtooth explo...
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length simulations
set up an OM, use an OEM to generate length data, estimate empirical LBIs, simple model based estimates using FLR wrappers for 3rd party methods evaluate robustness to uncertainty Introduction This tutorial describes how to simuation test data limited methods in FLR using a variety of other packages. Required packages To follow this tutorial yo...
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Length Based Indicators
\usepackage{lscape} \newcommand{\blandscape}{\begin{landscape}} \newcommand{\elandscape}{\end{landscape}} Outline Condition Operating Models for 5 contrasting species, sprat, turbot, pollack, bigeye and ray. Use a sawtooth exploitation history, i.e. gradual increase in \(F\) until the stock is overexploited after which a recover and long-term m...
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Publish DocuWestern Mediterranean Hake Example
Installation Historical Time Series Productivity and Reference Points Projection Summaries References This vignette evaluates factors that affect productivity and hence reference points using Western Mediterranean hake as an example. To do this we devlop a simulation model (i.e. an Operating Model) conditioned on the latest assessment that can b...
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Western Mediterranean Simulatiomns
Installation Historical Time Series Productivity and Reference Points Projection Summaries References This vignette evaluates factors that affect productivity and hence reference points using Western Mediterranean red mullet as an example. To do this we devlop a simulation model (i.e. an Operating Model) conditioned on the latest assessment that...
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validation of stock assessment methods
September, 2021 Case Study In the 2019 shortfin mako shark stock assessment it was noted that different assumptions and modelling frameworks led to different outcomes. Projections, and hence advuce, ignored large uncertainties about growth, age-at-maturity, natural mortality, stock-recruitment relationship, selectivity, and catch rates by fleet...
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