Comparing NFT Models

 

A variety of fisheries stock assessment models are available from the NOAA Fisheries Toolbox, each of which uses a different type of estimation method to produce results. 

 

Below are two tables to help you decide which model may best fit your needs. The first table gives a rough estimation of how widely model methods have been tested and/or evaluated. The second table compares some of the major features among each model.

 

If you would like a more in-depth comparison of model capabilities and methods, you can always download any of the models you are interested in and evaluate them individually side by side.

 

 

Core vs. Research Models

 

NFT models can be divided into to broad categories: Core Applications and Research Models. Core Applications are based on proven methods used extensively in peer reviewed stock assessments. Research Models have been tested within the NMFS organization but have not as yet been subjected to peer reviewed stock assessments.

 

Core Applications

Research Models

 

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Comparing Model Features

 

The table below compares the ability of NFT models to handle the following features:

 

Feature

Model

Data / Observation Error

A
I
M 		A
S
P
I
C 		C
S
A 		S
C
A
L
E 		V
P
A 		V
P
A
2
B
O
X 		A
M
A
K 		S
T
A
T
C
A
M 		A
S
A
P 		S
S
2

Total catch (landings+discards)

 yes Yes yes yes yes yes yes yes yes

Catch at age (CAA)

 Yes Yes Yes Yes Yes Yes

Catch at length (CAL)

 yes yes

Address variation in CAA or CAL

 yes yes yes yes

Age specific indices of abundance for tuning

 yes yes yes yes yes yes

Process / Model Specification

A
I
M 		A
S
P
I
C 		C
S
A 		S
C
A
L
E 		V
P
A 		V
P
A
2
B
O
X 		A
M
A
K 		S
T
A
T
C
A
M 		A
S
A
P 		S
S
2

Stock recruitment function

yes yes yes

Sexual dimorphism in growth rates

yes yes yes

Spatial heterogeneity

yes yes

Incorporate long term historical landings

yes yes yes yes yes

Handle gaps in age or length information


yes
yes yes yes yes yes

Multiple fleets

yes yes yes yes

Handle differences between sexes

yes yes yes

Automatic retrospective analyses

yes yes yes yes yes yes

Independently estimate temporal changes in catchability for surveys

 yes yes yes

Address variations in biological sampling intensity over time

yes yes yes yes

Consider measurement error for individual times series observations

 yes yes yes

Uncertainty / Forecasting / BRPs

A
I
M 		A
S
P
I
C 		C
S
A 		S
C
A
L
E 		V
P
A 		V
P
A
2
B
O
X 		A
M
A
K 		S
T
A
T
C
A
M 		A
S
A
P 		S
S
2

MCMC

yes yes yes yes

Bootstrap

yes yes yes yes yes yes

Estimation of BRP for F

 yes yes yes yes yes yes

Estimation of BRP for SSB

 yes yes yes yes yes

Linkage to external/internal forecasting program

 yes yes yes yes

Model Complexity

 A
I
M 		A
S
P
I
C 		C
S
A 		S
C
A
L
E 		V
P
A 		V
P
A
2
B
O
X 		A
M
A
K 		S
T
A
T
C
A
M 		A
S
A
P 		S
S
2

Model Complexity

1

1

1

2

2

3

3

3

3

4

 (1=Low, 2=Medium, 3=High, 4=Very High)

 

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NOAA Fisheries Toolbox Version 3.0

website last modified August 21, 2008