214 
Fishery Bulletin 111(3) 
Table 3 
Comparison of 3 models for changes in environmental time 
series data collected at 2 monitoring sites — West Point and 
Jefferson Head — in Port Madison, Puget Sound, Washing- 
ton, near sampling sites at which bottom trawl surveys were 
conducted from 1991 to 2012. Akaike’s information criteria 
adjusted for small sample size (AIC c ) was used to choose 
between the models: no change (“constant”), linear change 
(“linear”); or abrupt change (“change point”). Separate models 
were run for each monitoring site. 
Constant Linear Change point 
Temperature 
West Point 
0.00 
0.62 
2.85 
Jefferson Head 
0.00 
2.41 
2.85 
Surface salinity 
West Point 
0.00 
2.41 
2.85 
Jefferson Head 
7.89 
0.00 
10.81 
merer et al., 2000; Taylor et al., 2009). The processes 
that regulate juvenile survivorship and fish population 
dynamics in Puget Sound are not easily discerned be- 
cause of a paucity of long-term monitoring data. 
Conclusions 
Catch rates of resident groundfishes from a study 
area in Puget Sound indicated that a synchronous and 
abrupt decline in densities occurred in the late 1990s, 
counter to expectations formed on the basis of the ces- 
sation of commercial bottom trawling that preceded 
our sampling. Available evidence suggests that these 
declines may have resulted from a distributional shift 
rather than a demographic shift, although an analy- 
sis of data sets that span a spatial extent wider than 
our study area in Port Madison is needed to test this 
hypothesis. Therefore, considerable additional analy- 
ses are needed to address the response of species and 
food webs to fishing and to determine how localized 
closures, such as marine protected areas, may promote 
recovery of species. Further, there is a need to relate 
density shifts to environmental and biological changes 
(e.g., climatic drivers, human-induced habitat shifts, 
or trophodynamics). Finally, the unexpected shifts in 
localized catch rates in this study indicate a need for 
caution when time series are used in evaluating long- 
term shifts in population and community structure 
without consideration of whether the data are repre- 
sentative of entire populations. 
Acknowledgments 
We thank Charlie Eaton, the owner and operator of the 
RV Kittiwake, for the 2 decades of careful vessel op- 
eration and logistic assistance. Sampling took place as 
field research for the Fisheries Ecology class at 
the School of Aquatic and Fishery Sciences, Uni- 
versity of Washington (UW), and funding for ves- 
sel charter was provided by the teaching program. 
We thank the numerous teaching assistants and 
even more numerous students in the class over 
the years for their help with sorting and measur- 
ing fishes. Additional funding for the data analy- 
sis was provided by the SeaDoc Society, Lowell 
Wakefield Endowment, the UW Climate Impacts 
Group, and the Puget Sound Gatekeepers Alli- 
ance. We thank Wayne Palsson and 3 anonymous 
reviewers for helpful comments on the manu- 
script. We thank Chantel Wetzel for conducting 
preliminary analysis. 
Literature cited 
Anderson, D. M., P. M. Glibert, and J. M. Burkholder. 
2002. Harmful algal blooms and eutrophication: 
nutrient sources, composition, and consequenc- 
es. Estuaries 25:704-726. 
Anderson, P. J., and J. F. Piatt. 
1999. Community reorganization in the Gulf of Alaska 
following ocean climate regime shift. Mar. Ecol. Prog. 
Ser. 189:117-123. 
Andrews, K. S., P. S. Levin, S. L. Katz, D. Farrer, V. F. Gallucci, 
and G. Bargmann. 
2007. Acoustic monitoring of sixgill shark movements in 
Puget Sound: evidence for localized movement. Can. J. 
Zool. 85:1136-1143. 
Andrews, K. S., and T. P. Quinn. 
2012. Combining fishing and acoustic monitoring data 
to evaluate the distribution and movements of spotted 
ratfish Hydrolagus colliei. Mar. Biol. 159:769-782. 
Armstrong, D. A., C. Rooper, and D. Gunderson. 
2003. Estuarine production of juvenile Dungeness crab 
(Cancer magister) and contribution to the Oregon- 
Washington coastal fishery. Estuaries 26:1174-1188. 
Auster, P. J., R. J. Malatesta, R. W. Langton, L. Watling, P. C. 
Valentine, C. L. S. Donaldson, E. W. Langton, A. N. Shepard, 
and I. G. Babb. 
1996. The impacts of mobile fishing gear on seafloor 
habitats in the Gulf of Maine (northwest Atlantic): im- 
plications for conservation of fish populations. Rev. 
Fish. Sci. 4:185-202. 
Babcock, R. C., S. Kelly, N. T. Shears, J. W. Walker, and T. J. 
Willis. 
1999. Changes in community structure in temperate ma- 
rine reserves. Mar. Ecol. Prog. Ser. 189:125-134. 
Beck, M. W., K. L. Heck, K. W. Able, D. L. Childers, D. B. Egg- 
leston, B. M. Gillanders, B. Halpern, C. G. Hays, K. Hoshino, 
T. J. Minello, R. J. Orth, P. F. Sheridan, and M. P. Weinstein. 
2001. The identification, conservation, and management 
of estuarine and marine nurseries for fish and inverte- 
brates. Bioscience 51:633-641. 
Breitburg, D., D. W. Hondorp, L. A. Davias, and R. J. Diaz. 
2009. Hypoxia, nitrogen, and fisheries: integrating ef- 
fects across local and global landscapes. Annu. Rev. 
Mar. Sci. 1:329-349. 
Bromaghin, J. F., M. M. Lance, E. W. Elliott, S. J. Jeffries, A. 
Acevedo-Gutierrez, and J. M. Kennish. 
