Sogard and Berkeley: Movement, growth, and survival of Anoplopoma fimbria off Oregon 
243 
• Females 
30 40 50 60 70 80 
Initial fork length (cm) 
Figure 6 
Relationship between initial size and distance moved (great circle 
distance between tagging and recapture location) for sablefish {Ano¬ 
plopoma fimbria) initially captured off Newport, Oregon, during 
1996-1998 (tagging set 1) or 2003-2004 (tagging set 2). Only fish 
that moved >200 km from their tagging location and had reliable 
recapture locations are included. Regression lines were calculated 
separately for females (solid) and males (dashed). Fish from both 
tagging sets are combined. 
ture reported in logbooks and applied to total land- 
ings of sablefish in Oregon (all gears combined; Pacific 
Fisheries Information Network, website), annual land¬ 
ings in depths >900 m were <140 t before 2009, but 
>220 t during 2009-2013. Recapture rates after 2008 
were 4.2% for fish tagged from zone 2 and 4.5% for fish 
tagged from zone 3 (after adjusting for removal of all 
previously recaptured fish). Thus, the low early recap¬ 
ture rates of fish tagged in zone 3 and the increasing 
recaptures after 2008 likely reflect patterns in overall 
fishing effort and therefore do not support a depth ef¬ 
fect on discard mortality. 
Recapture rates from the shallower end of the sable¬ 
fish depth range may have been impacted by spatial 
closures. Offshore boundaries of the rockfish conserva¬ 
tion areas varied spatially and temporally after their 
implementation in 2002 (Keller et aL, 2014) and did 
not strictly match depth contours. In Oregon waters 
they were approximately 183 m (100 fm) for fixed gear 
and 274 to 457 m (150-250 fm) for bottom trawls from 
2003 to present. Fish that were initially captured and 
remained after tagging in depth zones 1 and 2 would 
have continued to be vulnerable to fixed-gear fisheries 
but may have avoided trawl capture. The depth effect 
on probability of recapture for tagging set 1, with re¬ 
duced recaptures in depth zone 1 compared with depth 
zone 2, may have been influenced, in part, by lower 
fishing pressure in the shallowest habitats. 
Surface temperatures appeared to influence discard 
mortality only for small fish <55 cm FL, which were re¬ 
captured at significantly lower rates under 
warmer surface temperatures than under 
cooler surface temperatures in depth zone 
2. Although the difference was not signifi¬ 
cant in zone 3, the overall recapture rate of 
small fish from zone 3 was very low (Table 
3), limiting detectability of a temperature 
effect. No differences in recapture rates be¬ 
tween surface temperatures were observed 
for medium or large fish at either depth. 
These size effects are consistent with prior 
laboratory studies. Observations of temper¬ 
ature-induced mortality were from experi¬ 
ments conducted primarily with fish <55 cm 
FL, for which body core temperatures in¬ 
creased at a faster rate than those of larger 
fish after transfer to warm water (Davis et 
aL, 2001). Davis and Parker (2004) also ob¬ 
served size-dependent effects on susceptibil¬ 
ity to postcapture stressors. 
implications of depth distribution 
Our results corroborate those of other stud¬ 
ies that indicate low abundance of imma¬ 
ture fish in deeper slope habitats (Jacobson 
et aL, 2001; Maloney and Sigler, 2008). Fish 
in the 2 small size modes captured during 
initial sampling in depth zone 1 did not 
occur in depth zones 2 or 3—a result con¬ 
sistent with a pattern of settlement in relatively shal¬ 
low water (<300 m). Recaptures of these smaller fish 
occurred throughout the slope depth gradient, with 
38% occurring >200 m deeper than the initial depth. 
Larger fish initially captured in zones 1 and 2 were 
likewise recaptured throughout the depth gradient, but 
only 17% were recaptured >200 m deeper than their 
initial depth. For fish initially captured in depth zone 
3, 44% were recaptured at depths >200 m shallower 
than their initial depth. These results provide only a 
snapshot view of depth-related movements because 
there is no information on depth distributions between 
capture and recapture. However, if recapture depths re¬ 
flect general depth preferences over time, they suggest 
that most fish remained relatively close to their initial 
depths within the time frame covered by this study. 
For fish initially captured in zones 1 and 2, there was 
no greater likelihood for smaller fish to be recaptured 
at deeper depths than larger fish, counter to our expec¬ 
tation of ontogenetic movement. The significant effect 
of initial size on recapture depths for fish from zone 
3 was also counter to expectations, with smaller fish 
more likely than larger fish to be recaptured in shal¬ 
lower depths. 
Some of these patterns were potentially biased by 
fishing effort; for example, low effort in deep slope wa¬ 
ters would limit our detection of fish that moved to 
those depths. The marked increase in recaptures after 
2008 of fish initially tagged in depth zone 3 (Fig. 9) 
presumably reflected increased fishing effort. Recap- 
