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Fishery Bulletin 1 10(2) 
Table 1 
Description and assigned injury code for injury types and severities for sablefish ( Anoplopoma fimbria ) caught on longline gear, 
for an estimation of discard mortality. 
Factor Description 
Hook injury location 
0 Hooked in cheek or parts of operculum 
1 Hooked in upper jaw: maxilla or premaxilla 
2 Hooked in lower jaw: dentary (mandible) 
3 Hooked in nose or snout 
4 Hooked in throat 
5 Hooked in eye 
6 Hooked around gill or gill arches 
Hook injury severity 
0 Minor: small puncture, flesh not torn, no abrasion 
1 Moderate: flesh torn; some abrasion; bones intact, eye orbit not punctured 
2 Severe: bones torn at insertion, severed or shattered, gills hooked but no broken gill arches, hooked through 
palatine into nose capsule, cheek bones shattered, hooked in throat and 
bleeding but not torn 
NT No tag: gill arches torn or bleeding, hook swallowed with substantial tears in throat; maxillary and premaxillary or 
dentary torn off; nose or snout smashed 
Amphipod predation injury 
0 No injury 
1 Moderate scale loss: 10% or less 
2 Heavy scale loss: greater than 10% 
Line and roller gear injury sustained on fins or body 
0 No injury 
1 Fin damage: caudal, pectoral, pelvic, dorsal, or anal fin 
2 Lacerations: line markings across body 
tagged because of the extreme severity of their injuries 
were assumed to have 0% survival and are represented 
in the equation as NT (having no tag and they were 
included in the total number of fish caught when cal- 
culating the recovery rate for each injury group). The 
survival rate of fish in each category was calculated with 
the following formula: 
S x = — x 0.965, (3) 
•TCq 
T 
1 0 
where all variables are the same as in Equation 2 and 
x represents the severity of the hook injury (0, 1, or 2). 
Results 
A large number of sablefish were captured (10,940) 
and tagged (10,508): 8838 fish were tagged during 
the 1989 survey and 1670 during the 1990 survey. 
A substantial number of fish were recaptured (1207 
fish, 11.49% recapture rate of tagged fish) between 9 
days and 19.2 years (mean = 3.4 yr, standard devia- 
tion = 4.5 yr) after tagging. Because some data were 
lacking for 81 fish, analyses were run with data from 
10,427 fish. An additional 432 fish were captured but 
not tagged because of the extreme injuries from capture 
or amphipod predation (NT in Eq. 2, see Materials and 
methods section). 
Logistic regression model 
The reduced model was chosen on the basis of the small- 
est AIC value. Several parameters were found to sig- 
nificantly affect recapture rates: year (which also can 
be considered to be a location effect), depth, severity of 
hook injury, and amphipod predation (Table 2, Fig. 2). 
Fish tagged in 1989 had a lower recapture rate (11.26%) 
than those tagged in 1990 (12.66%) (Table 3). Fish from 
the greatest depths (320-419 m) had a greater rate 
of recapture (14.33%) than fish captured at shallower 
depths (210-269 m, 10.61%; 270-319 m, 10.43%; Table 
3). Severity of hook injury also exhibited a significant 
effect on the recapture of tagged fish (Table 2). Fish 
with severe injuries had a lower recapture rate (8.49%) 
than those with minor (12.05%) or moderate (11.81%) 
injuries (Table 3). The confidence intervals surround- 
ing the parameters for severity of injury were relatively 
narrow, with the 95% confidence interval of the odds 
