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Fishery Bulletin 1 10(2) 
and management (Francis et al., 2007). However, in 
addition to these basic trophic relationships, it is neces- 
sary to understand the context in which prey are being 
selected. The effects of predation on both predator and 
prey populations change as prey densities vary. 
Although EBFM requires even more information than 
traditional single-species management approaches, 
managers, scientists, and stakeholders make use of 
less certain information both in less accessible systems 
and in those that are accessible but where temporal and 
spatial scales far exceed the capacity to collect local 
demographic data. For these reasons identifying specific 
management triggers based on comprehensive and col- 
lectable information has been proposed (Samhouri et 
ah, 2010) and the case made that uncertain data and 
imperfect advice must be embraced, as long as they are 
appropriate data (Ludwig et ah, 1993; Johannes, 1998; 
Frid et ah, 2008). Challenges to the use of EBFM in- 
clude “species conflicts,” where management and stake- 
holder interest in one target species may interfere with 
other species and often involve the assumed effects of 
large generalist predator(s) on recovering high value 
prey species, sometimes in and out of marine protected 
areas. Examples of generalist predators involved in 
management conflicts are groupers ( Epinephelus spp. 
[Ault et ah, 2006; Coleman and Koenig, 2010]), red 
snapper ( Lutjanus campechanus [Wells et ah, 2008; 
Cowan et ah, 2010]), cod ( Gadus morhua [Link and 
Garrison, 2002]), and striped bass ( Morone saxatilis 
[Paolisso, 2002; Walter et ah, 2003]). 
Marine reserves are becoming more widely consid- 
ered as a management tool for protecting a portion of 
breeding populations as interest in EBFM increases. 
However, in addition to providing a refuge from fishing 
mortality, marine reserves can enhance local popula- 
tions of large, resident, top-level predators (Martell 
et ah, 2000; McClanahan and Arthur, 2001). Among 
possible effects of a local increase in predator biomass 
is a decrease in a particular prey type (Graham et ah, 
2003). For example, this kind of interaction has been 
proposed for lingcod predation on rockfishes (Sebastes 
spp.) within marine reserves (Beaudreau and Essing- 
ton, 2007; 2009) and both are major targets of com- 
mercial fisheries. 
The following case study exemplifies necessary con- 
siderations for EBFM. Lingcod are targeted by both 
recreational and commercial fishermen along the west 
coast of North America. The 2000 stock assessment of 
lingcod from British Columbia to northern California 
estimated biomass at 11% of precommercial exploitation 
levels (Jagielo, et ah 1 ) and management substantially 
reduced fishing mortality to allow recovery of this stock. 
By 2006, lingcod stocks were declared fully recovered by 
the Pacific Fisheries Management Council. Lingcod are 
1 Jagielo, T. H., F. R. Wallace, and Y. W. Cheng. 2003. Assess- 
ment of lingcod (Ophiodon elongatus). Amendment 16-2: 
Rebuilding plans for darkblotched rockfish, Pacific ocean 
perch, canary rockfish, and lingcod. Environmental impact 
statement and regulatory analysis, 129 p. Pacific Fishery 
Management Council, Portland, OR. 
large (up to 152 cm total length [TL] and 59 kg) and 
fast growing. They are relatively site-attached, demer- 
sal, generalist predators, found on shallow northeastern 
Pacific rocky reefs. They roam across both rocky habitat 
and soft-bottom over distances of at least hundreds of 
meters, yet they demonstrate a high degree of site fidel- 
ity for time scales of at least weeks to months (Jagielo, 
1990; Smith et ah, 1990; Mathews, 1992; Yamanaka 
and Richards, 1993; Jagielo, 1999; Starr et ah, 2004). 
Although lingcod population dynamics have been 
studied from a fisheries perspective, very little is un- 
derstood about how this predator affects the structure 
of fish populations and assemblages on rocky reefs. 
A previous study of diet and habitat associations of 
demersal fishes on nearshore reefs along the Oregon 
Coast revealed that 282 adult lingcod had consumed 27 
identifiable species of fish and invertebrates. Of those 
134 prey items, no adult rockfishes were found and the 
contribution to total biomass by all rockfish prey was 
less than one percent (Steiner, 1979). However, no prior 
lingcod studies have described diet in relation to prey 
abundance. In order to assess differential selection, and 
thus characterize which prey types will most likely be 
selected, there must be an estimate of prey availability 
relative to consumption (Manley et al., 2002). The goal 
of this study was to describe the diet of adult lingcod off 
the coast of Oregon, to characterize relative patterns of 
consumption of transient and resident prey species by 
lingcod, and describe whether or not preference, defined 
as the differential consumption of one prey type over 
others in relation to availability, was evident. Specifi- 
cally, by using lingcod diet and prey abundance esti- 
mates off the coast of Oregon, I addressed the following 
questions: 1) Do lingcod prefer particular prey species, 
and 2) do lingcod preferentially target rockfishes? The 
answers to these questions were yes and no, respec- 
tively. This information can be used to more effectively 
manage a reserve system where both predator and prey 
populations are the focus of conservation efforts. 
Materials and methods 
Study area 
The nearshore zone off Oregon is generally exposed, has 
relatively high wave energy, and is influenced by long- 
shore currents. I sampled lingcod from two nearshore 
subtidal sites along the coast of Oregon: one south of 
Newport, referred to as site 1 (44°31'N lat.; 124°08 / W 
long.), and another south of Coos Bay, referred to as 
site 2 (43°16'N; 124°25'W) (Fig. 1). Both sites comprised 
high relief rocky reef, rocky flats, cobble, and sand at 
depths of 20 to 50 m. The reefs varied from small pin- 
nacles encompassing <10 m 2 to large boulder fields and 
bedrock flats that may exceed one km 2 in area. The area 
of exposed rock changes on temporal scales of months 
to decades, however, sand transport is greatest during 
the stormy winter months and relatively stable during 
the summer (Kulm et al., 1968). 
