von Szalay and Somerton: A method for predicting trawlability in the Gulf of Alaska 
503 
Clausen, D. M., and J. Heifetz. 
2002. The northern rockfish, Sebastes polyspinis, in Alas¬ 
ka: commercial fishery, distribution, and biology. Mar. 
Fish. Rev. 64(4): 1—28. 
Cordue, P. L. 
2007. A note on non-random error structure in trawl sur¬ 
vey abundance indices. ICES J. Mar. Sci. 64:1333-1337. 
Ellingsen, K. E., J. S. Gray, and E. Bj0rnbom. 
2002. Acoustic classification of seabed habitats using the 
QTC View system. ICES J. Mar. Sci. 59:825-835. 
Foote, K. G., H. P. Knudsen, and G. Vestnes. 
1983. Standard calibration of echo sounders and integra¬ 
tors with optimal copper spheres. Fisk.dir. Skr., Ser. 
Havunders. 17:335-346. 
Freitas, R., S. Silva, V. Quintino, A. M. Rodrigues, K. Rhynas, 
and W. T. Collins. 
2003. Acoustic seabed classification of marine habitats: 
studies in the western coastal-shelf area of Portugal. 
ICES J. Mar. Sci. 60:599-608. 
Greenstreet, S. P. R, I. D. Tuck, G. N. Grewar, E. Armstrong, 
D. G. Reid, and P. J. Wright. 
1997. An assessment of the acoustic survey technique, 
RoxAnn, as a means of mapping seabed habitat. ICES 
J. Mar. Sci. 54:939-959. 
Jagielo, T., A. Hoffman, J. Tagart, and M. Zimmermann. 
2003. Demersal groundfish densities in trawlable and un- 
trawlable habitats off Washington: implications for the 
estimation of habitat bias in trawl surveys. Fish. Bull. 
101:545-565. 
Jones, D. T., C. D. Wilson, A. De Robertis, C. N. Rooper, T. C. 
Weber, and J. L. Butler. 
2012. Evaluation of rockfish abundance in untrawlable 
habitat: combining acoustic and complementary sam¬ 
pling tools. Fish. Bull. 110:332-343. 
Kloser, R. J., N. J. Bax, T. Ryan, A. Williams, and B. A. 
Barker. 
2001. Remote sensing of seabed types in the Australian 
South East fishery; development and application of nor¬ 
mal incidence acoustic techniques and associate ‘ground 
truthing.’ Mar. Freshw. Res. 52:475-489. 
Maunder, M. N., and S. J. Harley. 
2011. Using cross validation model selection to determine 
the shape of nonparametric selectivity curves in fisheries 
stock assessment models. Fish. Res. 110:283-288. 
McConnaughey, R. A., and K. R. Smith. 
2000. Associations between flatfish abundance and surfi- 
cial sediments in the eastern Bering Sea. Can. J. Fish. 
Aquat. Sci. 57:2410-2419. 
Pirtle, J. L., T. C. Weber, C. D. Wilson, and C. N. Rooper. 
2015. Assessment of trawlable and untrawlable seafloor 
using multibeam-derived metrics. Methods Oceanogr. 
12:18-35. 
R Core Team. 
2015. R: a language and environment for statistical com¬ 
puting. R Foundation for Statistical Computing, Vi¬ 
enna, Austria. [Available from website, accessed June 
2015.] 
Richards, L. J. 
1986. Depth and habitat distributions of three species 
of rockfish ( Sebastes ) in British Columbia: observations 
from the submersible PISCES IV. Environ. Biol. Fish. 
17:13-21. 
Riegl, B. M., R. P. Moyer, L. J. Morris, R. W. Virnstein, and 
S. J. Purkis. 
2005. Distribution and seasonal biomass drift macroalgae 
in the Indian River Lagoon (Florida, USA) estimated 
with acoustic seafloor classification (QTCView, Echop- 
lus). J. Exp. Mar. Biol. Ecol. 326:89-104. 
Rooper, C. N., G. R. Hoff, and A. De Robertis. 
2010. Assessing habitat utilization and rockfish (Sebastes 
spp.) biomass on an isolated rocky ridge using acoustics and 
stereo image analysis. Can. J. Fish. Aquat. Sci. 67:1658- 
1670. 
Stauffer, G. (compiler). 
2004. NOAA protocols for groundfish bottom trawl sur¬ 
veys of the nation’s fishery resources. NOAA Tech. 
Memo. NMFS-F/SPO-65, 205 p. 
Stein, D. L., B. N. Tissot, M. A. Hixon, and W. Barss. 
1992. Fish-habitat associations on a deep reef at the edge 
of the Oregon continental shelf. Fish. Bull. 90:540-551. 
Thorson, J. T., M. E. Clarke, I. J. Stewart, and A. E. Punt. 
2013. The implications of spatially varying catchability 
on bottom trawl surveys of fish abundance: a proposed 
solution involving underwater vehicles. Can. J. Fish. 
Aquat. Sci. 70:294-306. 
von Szalay, P. G., and R. A. McConnaughey. 
2002. The effect of slope and vessel speed on the perfor¬ 
mance of a single beam acoustic seabed classification 
system. Fish. Res. 54:181-194. 
von Szalay, P. G., and N. W. Raring. 
2016. Data report: 2015 Gulf of Alaska bottom trawl survey. 
NOAA Tech. Memo. NMFS-AFSC-325, 249 p. 
Weber, T. C., C. Rooper, J. Butler, D. Jones, and C. Wilson. 
2013. Seabed classification for trawlability determined 
with a multibeam echo sounder on Snakehead Bank in 
the Gulf of Alaska. Fish. Bull. 111:68-77. 
Williams, K., C. N. Rooper, and R. Towler. 
2010. Use of stereo camera systems for assessment of 
rockfish abundance in untrawlable areas and for record¬ 
ing pollock behavior during midwater trawls. Fish. 
Bull. 108:352-362. 
Yoklavich, M. M., H. G. Greene, G. M. Cailliet, D. E. Sullivan, 
R. N. Lea, and M. S. Love. 
2000. Habitat associations of deep-water rockfishes in 
a submarine canyon: an example of a natural refuge. 
Fish. Bull. 98:625-641. 
Zimmermann, M. 
2003. Calculation of untrawlable areas within the boundar¬ 
ies of a bottom trawl survey. Can. J. Fish. Aquat. Sci. 60: 
657-669. 
