LeClair et al.: Seasonal changes in abundance and migration of Sebastes auriculatus and 5. caurinus 
303 
focus on single habitat types are also subject to bias 
when based on untested assumptions about habitat 
use, extent of home range, and site fidelity, as reviewed 
by Pittman and McAlpine (2003). These authors assert 
that if information on movement is not available, the 
assumption of single habitat use should be considered 
carefully or rejected entirely. They advocate for an as- 
sumption of the use of multiple habitats because it al- 
lows for the consideration of broader-scale movement 
and potential linkages among habitat types. Movement 
patterns, whether over short (e.g., diel) or long (e.g., 
seasonal, annual) temporal scales, rank as one of the 
most important behavioral sources of bias in fish stock 
assessments (Gayanilo and Pauly, 1997; Sparre and 
Venema, 1998). Statistical methods for incorporating 
patterns of fish movement into stock assessments are 
advancing (Hilborn and Walters, 1992; Methot, 2011), 
and the integration of known fish behavior parameters, 
such as diel and seasonal movements, will likely lead 
to substantial improvements in the accuracy of stock 
assessment models (Freon et al., 1993). 
Although the potential conservation benefits of indi- 
vidual marine protected areas (MPAs) have been dis- 
cussed for decades, there is currently a growing world- 
wide interest in establishing coordinated networks of 
MPAs that are ecologically joined over broad geographic 
regions, and this approach has been advocated for rock- 
fishes in the northeast Pacific Ocean (Yoklavich, 1998; 
Parker et al., 2000). Further, understanding migrations 
and other movement patterns of adult rockfishes has 
been identified as critical for formulating effective re- 
covery plans that may include MPAs for rockfishes in 
Puget Sound (Wyllie-Echeverria and Sato, 2005). The 
trend toward MPAs, however, is not without controver- 
sy — much of it centering on how to choose and config- 
ure MPA sites into mosaics that are adequately sized 
and placed to achieve prescribed conservation goals. 
The related and equally critical issue of how best to 
assess the performance of such networks once estab- 
lished is also a topic of considerable debate. The size 
and placement controversy owes much of its genesis to 
attempts at applying theories of island biogeography 
to the design of nature reserves (Diamond, 1975) and 
continues under what is widely known as the SLOSS 
(single large or several small) debate (Simberloff and 
Abele, 1982). Fundamental to the debate is the con- 
cept of source-sink dynamics (Pulliam, 1988) whereby, 
under optimal MPA performance conditions, increased 
regulatory protection is expected to result in a net ex- 
port of individuals to unprotected habitat or to mar- 
ginally suitable habitat within an MPA through larval 
advection, density-dependent displacements of later 
life history stages (spillover), or both. Many criteria for 
MPA design and site selection lack robust scientific jus- 
tification and most established temperate-water MPAs 
are not subjected to systematic, or even periodic, per- 
formance evaluations relative to fishery enhancement, 
species recovery, biodiversity preservation, or other 
desired outcomes. Although the number of theoretical 
MPA performance models is proliferating (Willis et al., 
2003), and presumably improving, these models rarely 
incorporate fish movement (but see Attwood and Ben- 
nett, 1995; Roberts and Sargant, 2002; Berezansky et 
al., 2011). Understanding the frequency, periodicity, and 
scale of fish movement will aid modelers and resource 
managers in choosing and scaling MPA sites, and in 
constructing MPA networks that adequately serve the 
ecological needs of species targeted for conservation. 
In this study, we seasonally monitored the abun- 
dance of 2 demersal rockfish species, brown rockfish 
(Sebastes auriculatus) and copper rockfish (S. cauri- 
nus) over a 7-year period on an artificial reef in Puget 
Sound, Washington. Counts for each of the 2 species 
were obtained by using scuba-based underwater visual 
censuses (UVCs) conducted over fixed-width strip tran- 
sects. Brown and copper rockfish belong to the subge- 
nus Pteropodus and occur sympatrically in many re- 
gions of the northeast Pacific Ocean, including much of 
Puget Sound. They share similar life history attributes, 
habitat affinities, behavioral characteristics, and food 
preferences (Washington et al.^; Lea et al., 1999; Stout 
et al., 2001; Love et al., 2002) and, in Puget Sound 
there is evidence of hybridization between the species 
(Seeb, 1998; Schwenke, 2012). In Washington State, 
they are managed as “bottomfish” and brown rockfish 
stock status throughout Puget Sound is classified as 
“precautionary,” whereas copper rockfish are classified 
as either precautionary (north Puget Sound) or “vul- 
nerable” (south Puget Sound), as defined by Palsson et 
ah'* 
Although tagging studies involving brown or copper 
rockfish have occurred throughout much of the range 
of these species and have encompassed a variety of in- 
vestigative objectives (Miller et al., 1967; Miller and 
Geibel, 1973; Dewees and Gotshall, 1974; Hallacher, 
1977; Walton^; Laufle®; Gowan, 1983; Mathews and 
Barker, 1983; Hueckel et al.^; Matthews, 1985; Mat- 
thews et al., 1987; Hartmann, 1987; Matthews, 1990a; 
Matthews, 1990b; Lea et al., 1999; Eisenhardt, 2004; 
Lowe et al., 2009; Tolimieri et al., 2009; Reynolds et 
al., 2010; Longabach, 2010; Starr et al.®; Hannah and 
^ Washington, P. M., R. Gowan, and D. H. Ito. 1978. A bio- 
logical report on eight species of rockfish (Sebastes spp.) from 
Puget Sound, Washington, 50 p. Northwest Alaska Fish. 
Cent. Proc. Rep. Northwest Alaska Fish. Cent., Natl. Mar. 
Fish. Serv., NOAA, Seattle. [Available at website.] 
Palsson, W. A., T.-S. Tsou, G. G. Bargmann, R. M. Buck- 
ley, J. E. West, M. L. Mills, Y. W. Cheng, and R. E. Pa- 
cunski. 2009. The biology and assessment of rockfishes 
in Puget Sound. Wash. Dep. Fish Wildl. FPT-09-04, 208 
p. [Available at website.] 
® Walton, J. M. 1979. Puget Sound artificial reef study. Wash. 
Dep. Fish., Tech. Rep. 50, 130 p. 
® Laufle, J. C. 1982. Biological development and materials 
comparisons on a Puget Sound artificial reef Wash. Dep. 
Fish. Tech. Rep. 72, 183 p. 
Hueckel, G. J., R. M. Buckley, and B. L. Benson. 1983. The 
biological and fishery development on concrete habitat en- 
hancement structures off Gedney Island in Puget Sound, 
Washington. Wash. Dept. Fish. Tech. Rep. 78, 67 p. 
® Starr, R. M., D. Wendt, K. T. Schmidt, R. Romero, J. Dur- 
yea, E. Loury, N. Yochum, R. Nakamura, L. Longabach, E. 
