GLOSSARY AND ACRONYMS

Term

Full Name

Description

Reference

ADAPT

Adaptive framework

A general approach to fitting VPA models. ADAPT is based on minimising the sum-of-squares over any number of indices of abundance to find best-fit parameters.

Gavaris (1988)

ALK

Age-length key

A table relating ages and lengths of a fish species

CAGEAN

Catch-at-AGE Analysis

Equivalent to ADAPT with separable VPA, but with more emphasis on the statistical rather than biological model.

Deriso et al. (1985)

CCAMLR

Commission for the Conservation of Antarctic Marine Living resources

CECAF

Fishery Committee for the Eastern Central Atlantic

CPUE

Catch per Unit of Effort

ICA

Integrated Catch-at-age Analysis

Equivalent to ADAPT,i.e. using a least-squares fit based on VPA and auxillary data, but the standard VPA catch formulation used in ADAPT is replaced by a separable VPA.

Patterson and Melvin (1995)

ICES

International Council for the Exploration of the Sea, based in Copenhagen

Multispecies VPA

Multispecies Virtual Population Analysis

Extends the cohort model with a model for the natural mortality that includes predator-prey relationships. Data as for VPA for all stocks, as well as stomach contents from at least one sample survey.

Sparre (1992) Magnusson (1995)

Pope’s Cohort Analysis

As with VPA, but the non-linear catch equation is replaced with an approximate explicit solution.

Pope (1972)

Separable VPA

Separable Virtual Population Analysis

The fishing mortality in the normal VPA model is separated into an exploitation rate and selectivity, which multiplied together estimate the fishing mortality. This produces estimates of catches, which can be fitted to observed catches even if no indices are available.

Pope and Shepherd (1982)

SPA

Sequential Population Analysis

Equivalent to VPA. This is the more common term used in USA and Canada.

Survivor Analysis

Analysis where the survivors are the focus of estimation rather than fishing mortality. Equivalent to VPA.

Doubleday (1976)

TAC

Total Allowable Catch

Management measure. The total amount of catch allowed to be taken from a particular stock in a particular year.

VPA

Virtual Population Analysis

A general method to model the progression of a cohort through time. VPA became useful when the Baranov catch equation incorporating observed catches could be solved sequentially.

Gulland (1965) Fry (1949)

XSA

Extended Survivor Analysis

A VPA with no catch errors is tuned with age-specific CPUE indices. The model is fitted through a specialised robust iteration technique, rather than general least-squares. The procedure includes an iterative weighting of CPUE indices.

Shepherd (1991, 1999)

Term	Full Name	Description	Reference
ADAPT	Adaptive framework	A general approach to fitting VPA models. ADAPT is based on minimising the sum-of-squares over any number of indices of abundance to find best-fit parameters.	Gavaris (1988)
ALK	Age-length key	A table relating ages and lengths of a fish species
CAGEAN	Catch-at-AGE Analysis	Equivalent to ADAPT with separable VPA, but with more emphasis on the statistical rather than biological model.	Deriso et al. (1985)
CCAMLR	Commission for the Conservation of Antarctic Marine Living resources
CECAF	Fishery Committee for the Eastern Central Atlantic
CPUE	Catch per Unit of Effort
ICA	Integrated Catch-at-age Analysis	Equivalent to ADAPT,i.e. using a least-squares fit based on VPA and auxillary data, but the standard VPA catch formulation used in ADAPT is replaced by a separable VPA.	Patterson and Melvin (1995)
ICES	International Council for the Exploration of the Sea, based in Copenhagen
Multispecies VPA	Multispecies Virtual Population Analysis	Extends the cohort model with a model for the natural mortality that includes predator-prey relationships. Data as for VPA for all stocks, as well as stomach contents from at least one sample survey.	Sparre (1992) Magnusson (1995)
Pope’s Cohort Analysis		As with VPA, but the non-linear catch equation is replaced with an approximate explicit solution.	Pope (1972)
Separable VPA	Separable Virtual Population Analysis	The fishing mortality in the normal VPA model is separated into an exploitation rate and selectivity, which multiplied together estimate the fishing mortality. This produces estimates of catches, which can be fitted to observed catches even if no indices are available.	Pope and Shepherd (1982)
SPA	Sequential Population Analysis	Equivalent to VPA. This is the more common term used in USA and Canada.
Survivor Analysis		Analysis where the survivors are the focus of estimation rather than fishing mortality. Equivalent to VPA.	Doubleday (1976)
TAC	Total Allowable Catch	Management measure. The total amount of catch allowed to be taken from a particular stock in a particular year.
VPA	Virtual Population Analysis	A general method to model the progression of a cohort through time. VPA became useful when the Baranov catch equation incorporating observed catches could be solved sequentially.	Gulland (1965) Fry (1949)
XSA	Extended Survivor Analysis	A VPA with no catch errors is tuned with age-specific CPUE indices. The model is fitted through a specialised robust iteration technique, rather than general least-squares. The procedure includes an iterative weighting of CPUE indices.	Shepherd (1991, 1999)