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Notes:

Model 1 was applied to data from all release and recapture sites aggregated into 10 day periods. All tag release cohorts were pooled.

For variants of Model 1 were examined

a - both species have common preference of offshore habitat

both species equally vulnerable to the gear

b - yellowfin and bigeye differ in preference of offshore habitat

both species equally vulnerable to the gear

no improvement over a

c - both species have common preference of offshore habitat

yellowfin and bigeye have different vulnerability to gear

significant improvement over a

d - yellowfin and bigeye differ in preference of offshore habitat

yellowfin and bigeye have different vulnerability to gear

significant improvement over both a and c.

Two derived variables are included: half-life and harvest ratio. Half life is a simple function of Z and is the time required for half of the population to decay. Harvest ratio is the ratio of fishing mortality to total mortality.

Differences in half life are only apparent when both attrition and fishing mortality are species dependent.