Publications by L Kell

Document

10.08.2021

Summary Reference Points Productivity Stock and recruitment Regimes Projection References Summary The aim of theses examples is to evaluate the biological factors that affect productivity. North East Atlantic mackerel is used as an example. The estimation of the current ICES Precautionary Approach (\(PA\)) and Maximum Sustainable Yeild (\(MSY\))...

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Performance Metrics

10.08.2021

Required packages To follow this tutorial you should have installed the following packages: CRAN: FLR: FLCore You can do so as follows: install.packages(c("iterators")) install.packages(c("FLCore"), repos="http://flr-project.org/R") library(devtools) install_github("lauriekell/FLCandy") Section library(plyr) library(reshape) library(randtests...

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Atlantic Yellowfin

24.09.2021

Scenarios Historical Assessments Steepness: 0.8, 0.9 Fleets: Annual, Seasonal Projections Status Quo Regime shift: change M & growth for 2020 onwards Regime shift: change in Virgin Biomass (\(B_0\)) or \(R_0\) from 2020 onwards These are then run these with and without a shock, i.e. increase M in 2020 for 1 season. Management, i.e. catchs...

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Atlantic Bigeye

24.09.2021

Scenarios Historical Assessments Steepness: 0.7, 0.8, 0.9 Natural Mortality: Reference and Alternative Sigma R: 0.2, 0.4 and 0,6 Projections Status Quo Regime shift: change M & growth for 2020 onwards Regime shift: change in Virgin Biomass (\(B_0\)) or \(R_0\) from 2020 onwards These are then run these with and without a shock, i.e. increas...

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clinate scenarios

14.10.2021

Figure 1 Red mullet: reference case time series with worm plots. Figure 2 Red mullet: time series by scenario. Figure 3 Red mullet: possible quantities by scenario. North Sea cod Figure 4 North Sea cod: time series by scenario relative to reference case Monte Carlo replicate Figure 5 North Sea cod: time series by scenario relative to referen...

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Lengt

15.11.2021

\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 ...

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Climate Change Med stocks

25.11.2021

Red Mullet Figure 1. Time series, with MSY estimated with a Beverton and Holt stock recruitment relationship. Figure 2. Reference case projections, for Status Quo, at \(F_{0.1}\) and \(F_{MSY}\). Figure 3. Production functions and reference points for 50% increase in M from 2020 onwards, points show \(F_{0.1}\) (dashed) and \(F_{MSY}\) (solid)...

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Comparison of length based idicators and methods

17.05.2022

\usepackage{lscape} \newcommand{\blandscape}{\begin{landscape}} \newcommand{\elandscape}{\end{landscape}} Figure 1. Example of length based indicators and estimators for Sprat. Calculate true positive rate (sensitivity) and true negative rate (specificity) for identifying \(F/F_{MSY}\) Then calculate the True Skill Statistic i.e. TSS = TPR + TN...

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Length Base Methods

19.05.2022

\usepackage{lscape} \newcommand{\blandscape}{\begin{landscape}} \newcommand{\elandscape}{\end{landscape}} Figure 1 Length data Figure 2. Example of length based indicators and estimators for Sprat. \(F/F_{MSY}\) true positive rate (sensitivity) and true negative rate (specificity) Calculate the True Skill Statistic TSS = TPR + TNR - 1 = TPR - F...

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