Sampling error associated with estimates of species composition and age composition
of commercial groundfish landings in Oregon from 1989 to 1991 is documented to evaluate
the impact of variable landing data on fisheries management and monitoring programs. The
statistical reliability and bias associated with two multistage sampling designs are
investigated...
Life-history organization of the cutthroat trout (Oncorhvnchus clarki) may be viewed at various levels, including species, subspecies, metapopulation, population, or individual. Each level varies in spatial scale and temporal persistence, and components at each level continually change with changes in environment. Cutthroat trout are widely distributed throughout the western USA,...
Considerable controversy exists about how fish assemblages are
organized. I explicitly took fish movement into account while I
studied the effects of disturbance, habitat complexity, and predation
at different times of the summer to understand the major factors
influencing assemblage structure in a high desert Oregon stream. The
effects of...
Demographic characteristics of juvenile Dover sole
(Microstomus pacificus) were examined in relation to
physical and biotic factors to develop a hypothesis
explaining annual variations in recruitment. Surveys were
conducted along the Oregon continental shelf at depths
between 50-400 m bimonthly during 1989 and annually (in
March) between 1990 and 1993....
The groundfish trawl fishery operating off the coasts of Oregon
and Washington 1985-1987 caught six major assemblages of species
which could be treated as units in developing mixed-species
management plans. Eighty-one percent of the tows observed on
commercial vessels were consistently placed in one of the assemblage
designations using three...