205 
Shifts in the estuarine demersal fish 
community after a fishery closure in 
Puget Sound, Washington 
Abstract— Puget Sound is one of the 
largest and most ecologically signifi- 
cant estuaries in the United States, 
but the status and trends of many 
of its biological components are 
not well known. We analyzed a 21- 
year time series of data from stan- 
dardized bottom trawl sampling 
at a single study area to provide 
the first assessment of population 
trends of Puget Sound groundfishes 
after the closure of bottom trawl 
fisheries. The expected increase in 
abundance was observed for only 3 
of 14 species after this closure, and 
catch rates of most (10) of the abun- 
dant species declined through time. 
Many of these changes were step- 
wise (abrupt) rather than gradual, 
and many stocks exhibited changes 
in catch rate during the 3-year pe- 
riod from 1997 through 2000. No 
detectable change was recorded for 
either temperature or surface salin- 
ity over the entire sampling period. 
The abrupt density reductions that 
were observed likely do not reflect 
changes in demographic rates but 
may instead represent distributional 
shifts within Puget Sound. 
Manuscript submitted 27 August 2012. 
Manuscript accepted 3 April 2013. 
Fish. Bull. 111:205-217 (2013). 
doi 10.7755/FB. 11 1.3.1 
The views and opinions expressed 
or implied in this article are those of the 
author (or authors) and do not necessar- 
ily reflect the position of the National 
Marine Fisheries Service, NOAA. 
Timothy E. Essington (contact author) 
Kathryn Dodd 
Thomas P. Quinn 
Email address for contact author: essing@uw.edu 
School of Aquatic and Fishery Sciences 
University of Washington 
UW Box 355020 
Seattle, Washington 98195 
Estuaries support diverse marine 
communities and act as nursery ar- 
eas for many coastal populations 
(Beck et ai., 2001; Armstrong et al., 
2003), but they are the most heavily 
affected marine ecosystems (Lotze et 
al., 2006; Halpern et al., 2008) be- 
cause they also commonly serve as 
ports for shipping, support commer- 
cial and recreational fisheries, and 
are used as recreational areas. Be- 
cause of their close link with terres- 
trial systems, they are susceptible to 
coastal eutrophication (Carpenter et 
al., 1998) that leads to hypoxia (Diaz, 
2001; Breitburg et al., 2009), harmful 
algal blooms (Anderson et al., 2002), 
and concentrations of contaminants 
(Nichols et al., 1986). Because of the 
myriad ecosystem services they pro- 
vide (Guerry et al., 2012) and the 
many human activities that may im- 
pair their delivery, there is a grow- 
ing effort to protect and restore these 
ecosystems. However, assessment of 
the efficacy of protection measures is 
often hindered by the lack of long- 
term, standardized data and by con- 
founding changes in many aspects of 
the ecosystem, such as fishery man- 
agement, shoreline protection, and 
water quality. 
Puget Sound is one of the larg- 
est and most ecologically significant 
estuaries in the United States, sup- 
porting a rich fauna with more than 
200 fish species, 26 marine mam- 
mals, more than 100 bird species and 
a high diversity of invertebrates. 1 It 
is the second-largest estuary (2330 
km 2 ) in the coterminous United 
States, and its watershed supports 
a large and growing human popula- 
tion. Land alteration and habitat loss 
(Levings and Thom, 1994), fishing, 2 
and toxic contaminants (Landahl et 
al., 1997) have had widespread ef- 
fects on this ecosystem. Currently, 
8 fish species or fish stock in Puget 
Sound are protected under the U.S. 
Endangered Species Act, and many 
others are identified as being at risk 
(Musick et ah, 2000). Tagging stud- 
ies, genetic analyses, and differences 
in toxic contaminant levels all in- 
dicate that Puget Sound stocks of 
various fish species are distinct from 
coastal stocks (Day, 1976; Andrews et 
al., 2007; West et al., 2008; Andrews 
and Quinn, 2012). Notwithstand- 
ing these issues, much of the area 
1 Ruckelshaus, M. H., and M. M. McClure. 
2007. Sound science: synthesizing eco- 
logical and socioeconomic information 
about the Puget Sound ecosystem. U.S. 
Dep. Commer., NOAA, National Marine 
Fisheries Service, Northwest Fisher- 
ies Science Center. Seattle, WA. 93 p. 
[Available from http://www.nwfsc.noaa. 
gov/research/shared/sound_science/docu- 
ments/sound_science_finalweb.pdf. 
2 Palsson, W. A., T. J. Northrup, and M. W. 
Barker. 1998. Puget Sound ground- 
fish management plan, 48 p. Washing- 
ton Department of Fish and Wildlife, 
Olympia, WA. [Available from http:// 
wdfw.wa. gov/publications/00927/. | 
