Conrath: Reproductive potential of Sebastes variabilis and S. polyspinis 
149 
skipped spawning with size or age. This pattern has also 
been documented for deepwater rockfish species in the 
Gulf of Alaska (Conrath, 2017). A relationship between 
incomplete fertilization or fertilization failure and size 
was not observed in this study. 
Reproductive failure has the potential to affect recruit¬ 
ment to the fishery of these 2 species in the Gulf of Alaska; 
therefore, it is critical to understand how this aspect of the 
life history of northern and light dusky rockfish should 
inform the management of these species. Research results 
indicate that spawning stock biomass or estimates of 
oocyte production per recruit can be inflated when adult 
fish that are not spawning are included as a part of the 
spawning stock (Rideout et al., 2005; Rideout and Rose, 
2006; Sitar et al., 2014). Skipped spawning likely varies 
with metabolic condition, reflecting environmental param¬ 
eters. Therefore, the proportion of a population of northern 
rockfish or light dusky rockfish that is not spawning likely 
varies annually, and there may be other temporal patterns 
in reproductive success related to changes in abundance 
of parasites, prey, and predators and in environmental 
parameters. Time-series data on reproductive parameters 
and specifically on rates of skipped spawning are needed 
to understand the implications for fish populations and 
their management (Rideout and Tomkeiwicz, 2011). 
Acknowledgments 
I thank B. Knoth, C. Rooper, D. Benjamin, M. Yang, and 
A. Vijgen for invaluable field and laboratory assistance. 
I am grateful to the captains and crew of the commercial 
fishing vessels chartered to participate in this research, 
the F/V Gold Rush and the F/V Pacific Storm, including 
B. Ashley, D. Ashely, and S. Hockema. I thank my funding 
sources: the North Pacific Research Board, the Alaska 
Coral and Sponge Initiative of the National Marine 
Fisheries Service, and the Habitat and Ecological Pro¬ 
cesses Research Program of the NOAA Alaska Fisheries 
Science Center. 
Literature cited 
Allen, M. J., and G. B. Smith. 
1988. Atlas and zoogeography of common fishes in the Bering 
Sea and northeastern Pacific. NOAA Tech. Rep. NMFS 66, 
151 p. 
Berkeley, S. A., C. Chapman, and S. M. Sogard. 
2004. Maternal age as a determinant of larval growth and 
survival in a marine fish, Sebastes melanops. Ecology 
85:1258-1264. 
Beyer, S. G., S. M. Sogard, C. J. Harvey, and J. C. Field. 
2015. Variability in rockfish ( Sebastes spp.) fecundity: species 
contrasts, maternal size effects, and spatial differences. 
Environ. Biol. Fish. 98:81-100. 
Bobko, S. J., and S. A. Berkeley. 
2004. Maturity, ovarian cycle, fecundity, and age-specific par¬ 
turition of black rockfish ( Sebastes melanops). Fish. Bull. 
102:418-429. 
Boehlert, G. W., W. H. Barss, and P. B. Lamberson. 
1982. Fecundity of the widow rockfish, Sebastes entomelas, off 
the coast of Oregon. Fish. Bull. 80:881-884. 
Boehlert, G. W., M. Kusakari, and J. Yamada. 
1987. Reproductive mode and energy costs of reproduction 
in the genus Sebastes. In Proceedings of the international 
rockfish symposium; Anchorage, AK, 20-22 October 1986, 
p. 143-152. Alaska Sea Grant Rep. 87-02. Alaska Sea Grant 
Coll. Program, Univ. Alaska Fairbanks, Fairbanks, AK. 
Bond, N. A., M. F. Cronin, H. Freeland, and N. Mantua. 
2015. Causes and impacts of the 2014 warm anomaly in the 
NE Pacific. Geophys. Res. Lett. 42:3414-3420. 
Bowers, M. J. 
1992. Annual reproductive cycle of oocytes and embryos of 
yellowtail rockfish Sebastes flavidus (Family Scorpaeni- 
dae). Fish. Bull. 90:231-242. 
Cavole, L. M., A. M. Demko, R. E. Diner, A. Giddings, I. Koester, 
C. M. L. S. Pagniello, M.-L. Paulsen, A. Ramirez-Valdez, S. M. 
Schwenck, N. K. Yen, et al. 
2016. Biological impacts of the 2013-2015 warm-water anom¬ 
aly in the Northeast Pacific: winners, losers, and the future. 
Oceanography 29:273-285. 
Chilton, E. A. 
2007. Maturity of female northern rockfish Sebastes poly¬ 
spinis in the central Gulf of Alaska. Alaska Fish. Res. Bull. 
12:264-269. 
2010. Maturity and growth of female dusky rockfish 
(Sebastes variabilis) in the central Gulf of Alaska. Fish. 
Bull. 108:70-78. 
Clausen, D. M., and J. Heifetz. 
2002. The northern rockfish, Sebastes polyspinis, in Alaska: 
commercial fishery, distribution, and biology. Mar. Fish. 
Rev. 64(4): 1-28. 
Conrath, C. L. 
2017. Maturity, spawning omission, and reproductive com¬ 
plexity of deepwater rockfish. Trans. Am. Fish. Soc. 
146:495-507. 
Conrath, C. L., and B. Knoth. 
2013. Reproductive biology of Pacific ocean perch in the Gulf 
of Alaska. Mar. Coast. Fish. 5:21-27. 
Dick, E. J. 
2009. Modeling the reproductive potential of rockfishes 
(Sebastes spp.). Ph.D. diss., 229 p. Univ. Calif. Santa Cruz, 
CA. 
Engelhard, G. H., and M. Heino. 
2006. Climate change and condition of herring ( Clupea har- 
engus) explain long-term trends in extent of skipped repro¬ 
duction. Oecologia 149:593-603. 
Hannah, R. W., and S. J. Parker. 
2007. Age-modulated variation in reproductive development 
of female Pacific ocean perch (Sebastes alutus) in waters off 
Oregon. In Biology, assessment, and management of North 
Pacific rockfishes. Alaska Sea Grant Rep. 07-01 (J. Heifetz, 
J. DiCosimo, A. J. Gharrett, M. S. Love, V. M. O’Connell, 
and R. D. Stanley, eds.), p. 161-180. Alaska Sea Grant Coll. 
Program, Univ. Alaska Fairbanks, Fairbanks, AK. 
Hothorn, T., F. Bretz, and P. Westfall. 
2008. Simultaneous inference in general parametric models. 
Biom. J. 50:346-363. 
Hulson, P.-J. F., J. Heifetz, D. H. Hanselman, S. K. Shotwell, and 
J. N. Ianelli. 
2015. Assessment of the northern rockfish stock in the Gulf of 
Alaska. In Stock assessment and fishery evaluation report 
for the groundfish resources of the Gulf of Alaska, p. 889- 
974. North Pacific Fish. Manage. Counc., Anchorage, AK. 
[Available from website.] 
