Bayesian Analysis
Why?
Include all information
Previous experiments
Other populations/species
Expert judgment
Calculate probabilities of alternative
hypotheses
Estimate uncertainty
Easy to implement
Example
Tagging to estimate survival
A stock as

Some stock assessment
concepts
Topics
Modeling fishing mortality
Modeling selectivity
Standard deviations and effective sample
sizes for likelihood functions
Recruitment deviates
Fishing mortality
Solve the catch equation
Estimate Ft,a and fit to ca

A statistical age-structured
catch-at-length analysis
California scorpionfish application
Model
Age-structured
Single sex
Two fisheries (commercial in weight and
recreation in numbers)
Catch taken in middle of year to approximate
continuous fishing

Probability and Likelihood
Probability distributions
Probability of an event given a probability
distribution
Probability distribution defined by its form
and the values of its parameters
Probability density function for continuous
variables
n x
n x
P(

Fitting a model to data
The components
1.
2.
3.
4.
5.
Model of the population dynamics
Initial conditions
Data
Observation model
Objective function
The components
X t +1 = f ( X t )
Population dynamics model
X1 = I
Initial conditions
cfw_ O1 ,.OT
Data
~

Introduction to modern statistical
fisheries stock assessment
IMARPE
PFRP
Mark Maunder (IATTC)
Kevin Piner (NMFS)
Simon Hoyle (IATTC)
Inter-American Tropical Tuna Commission
8604 La Jolla Shores Drive
La Jolla, CA 92037-1508
USA
Tel: (858) 546-7027
Fax: (