Rodgveller et al.: Age at maturity, skipped spawning, and fecundity of female Anoplopoma fimbria 
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— — — WinterSSI 
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1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 
Figure 6 
Ratio of the estimates of spawning stock biomass (SSB) when different female maturity 
curves were incorporated into the population model for sablefish (Anoplopoma fimbria ) in 
Alaska in relation to the SSB when maturity data currently used in the stock assessment 
of sablefish (base SSB) are used. The maturity curves used in the model included data col- 
lected in winter 2011 when fish that would skip spawning were classified as mature (Win- 
terSSM), in winter 2011 when fish that would skip spawning were classified as immature 
(WinterSSI), in 2011 during the annual summer longline survey conducted by the NOAA 
Alaska Fisheries Science Center (AFSC) (LL2011), and the mean of data collected during 
AFSC annual summer longline surveys, 1996-2012. 
not move large distances during the spawning season. 
During the winter survey, we deployed popoff satellite 
tags on 4 fish >850 mm in fork length. We assumed 
that the tagged fish were female because, in summer 
longline surveys, only 0.5% of fish >850 mm in fork 
length have been male. Tags were preprogrammed to 
pop off fish within the current spawning season (35-52 
days after release), and the geolocation of a tag was re- 
corded when it was released from a fish. The 2 fish that 
were released where they were caught on the shelf re- 
mained within 1 km of their tagging location, and the 
2 fish that were captured on the slope but released 75 
km away on the shelf moved to locations in the vicinity 
of their capture site (within 0.5 km or 9 km). 
As with Pacific halibut and Atlantic cod, habitat use 
by sablefish during the spawning season may be re- 
lated to spawning. Data on sablefish movement in the 
winter is greatly lacking because there are no surveys 
or directed fisheries in the winter. The use of popoff 
satellite tags enables research on movement to occur 
during this period. Future research on habitat use and 
movement related to spawning of sablefish is badly 
needed both for identifying spawning areas and for 
tracking the movement of fish that skipped spawning 
and those that spawned. 
Rates of skipped spawning are highly variable 
among species; a range from 9% to 86% has been re- 
ported in 21 freshwater and marine species (reviewed 
in Secor, 2008). Rates are higher for species that have 
to make large-scale, energetically costly migrations be- 
cause fish that skip spawning can forgo these migra- 
tions. Skipped spawning rates are also hypothesized to 
be higher for long-lived species because they have the 
ability to skip spawning to increase their survival and 
growth and, thereby, to maximize their lifetime repro- 
ductive output (Rideout et ah, 2005). For example, stur- 
geons (Acipenseridae), Pacific halibut, and Atlantic cod 
are long-lived fish that make large-scale spawning mi- 
grations and have skipped spawning rates of 10-86% 
(Loher and Seitz, 2008; Skjaeraasen et al., 2012; Kuha- 
jda, 2014). Sablefish move long distances during their 
lives, but it is unknown whether their movements are 
related to spawning. However, they are long-lived and 
have a maximum age similar to that of other species 
that skip spawning. 
Skipped spawning is related to energy reserves (i.e., 
relative liver weight) and body condition (the ratio of 
body weight to length) for Atlantic cod, and rates of 
skipped spawning can vary by year (Skjaeraasen et al., 
2009; Skjaeraasen et al., 2012). Both of these factors 
