Ecological Archives E088-042-A1

Gjert E. Dingsør, Lorenzo Ciannelli, Kung-Sik Chan, Geir Ottersen, and Nils Chr. Stenseth. 2007. Density dependence and density independence during the early life stages of four marine fish stocks. Ecology 88:625–634.

Appendix A. Table of covariates used in the modeling.

TABLE A1. List of variables used in the analysis of early life-stage abundances. Variables that were significantly affected by those listed in the first column are in bold in the third column (modeled variables) and those that were not affected are in regular characters.

Variable

Definition

Modeled variables

Survey gear

Natural logarithm of maturing capelin stock biomass.

Cap0

Acoustic survey

Natural logarithm of catch numbers of mature capelin.

Cap0

Fisheries statistics

Natural logarithm of capelin age-0 abundance.

Cap1

Pelagic trawl survey

Mean length of capelin at age-0.

Cap1

Pelagic trawl survey

Natural logarithm of capelin age-1 abundance.

 

Acoustic survey

Natural logarithm of cod spawning stock biomass.

Cod0

VPA estimate

Mean age in cod spawning stock.

Cod0

VPA estimate

Natural logarithm of cod age-0 abundance.

Cap0, Had0, Her0, Cod1, Cap1, Had1, Her1

Pelagic trawl survey

Mean length of cod at age-0.

Cod1

Pelagic trawl survey

Natural logarithm of cod age-1 abundance.

 

Bottom trawl survey

Catchability factor

Cod1, Had1

Bottom trawl survey

Natural logarithm of haddock spawning stock biomass.

Had0

VPA estimate

Mean age in haddock spawning stock.

Had0

VPA estimate

Natural logarithm of haddock age-0 abundance.

Had1

Pelagic trawl survey

Mean length of haddock at age-0.

Had1

Pelagic trawl survey

Natural logarithm of haddock age-1 abundance.

 

Bottom trawl survey

Natural logarithm of herring spawning stock biomass.

Her0

SeaStar estimate

Mean age in herring spawning stock.

Her0

SeaStar estimate

Natural logarithm of herring age-0 abundance.

Her1

Pelagic trawl survey

Mean length of herring at age-0.

Her1

Pelagic trawl survey

Natural logarithm of herring age-1 abundance.

 

Acoustic survey

Center of gravity in N-S direction of investigated species at age-0.

Cap1, Cod1, Had1, Her1

Pelagic trawl survey

Center of gravity in E-W direction of investigated species at age-0.

Cap1, Cod1, Had1, Her1

Pelagic trawl survey

Natural logarithm of number of cod at age 3–6.

Cap0, Cod0, Had0, Her0, Cap1, Cod1, Had1, Her1

VPA estimate

Natural logarithm of number of herring at age 1–5.

Cap0, Cap1

Acoustic survey

Mean winter (Dec.-March) temperature (oC) 0–200m at the Kola section.

Cap0, Cod0, Had0, Her0, Cap1, Cod1, Had1, Her1

CTD-data

Mean summer (June-Aug.) temperature (oC) 0–200m at the Kola section.

Cap0, Cod0, Had0, Her0

CTD-data



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