A theoretical framework for economic fishery management was
developed. Extensive isocline analysis of a general fishery model
yielded a detailed look at the possible equilibrium behavior of a
system that was allowed to vary in terms of the levels of its
environmental parameters, its composition, and the response functions
governing...
Laboratory stream communities in simulated old growth second
order streams were sampled June 1984 and June 1985 to advance an
understanding of their organization and development, and their
response to an environmental perturbance, the toxicant dieldrin. An
interpenetrating hierarchical view of habitats and community
subsystems was taken to conceptualize community...
To understand the influence of selective harvesting on
the adaptive capacity of fish populations in changing
environments, a computer simulation model was developed. In
the model, hypothetical populations were composed of five
different life histories, which were genetically determined.
Each life history type had its own rate of survival and...
The purpose of this research was to examine the
effects of fishing on life history parameters of the spiny
lobster, Panulirus homarus. The study areas selected had
different levels of fishing pressure but relatively similar
habitats. The lowest fishing effort was found in Hadbin
while the highest fishing effort was...
The eastern margin of the Eastern North Pacific Ocean
was classified into physiographic regions based on a suite
of physical characteristics. Information on cultural and
biological characteristics of this area was meshed with this
classification. The result was a classification of the
Eastern North Pacific into natural-cultural systems whose
boundaries...
Although nearshore macroinvertebrates are integral members of high
mountain lentic systems, knowledge of ecological factors influencing their
distributions is limited. Factors affecting distributions of nearshore
macroinvertebrates were investigated, including microhabitat use and
vertebrate predation, in the oligotrophic lakes of North Cascades National
Park Service Complex, Washington, USA, and the conformity...
The restoration of rivers and streams should be based on a
strong conceptual framework. Streams are developing systems. As
such, streams exhibit temporal behaviors that change with changing
stream environments. Underlying the dynamic development of streams is
potential capacity. Streams express this capacity as an array of
habitats over time...
Waldo Lake, located in the Oregon Cascades, is
considered to be one of the most dilute lakes in the
world. Even with very low nutrient concentrations and
sparse populations of zooplankton, introduced fish in the
lake are large in size and in good condition when compared
to fish from other...
The long-toed salamander (Ambystoma macrodactylum)
is the top vertebrate predator in fishless high-elevation
lakes in North Cascades National Park Service Complex
(NOCA), Washington. The purpose of this research was to
determine the effects of physico-chemical factors and
introduced trout on abundance and behavior of A.
macrodactylum larvae. Although high-elevation lakes...
Resident bull trout (Salvelinus confluentus) may be particularly vulnerable to human related disturbance, however very few studies have focused on resident bull trout populations. The abundance of bull trout is one measure of the strength and potential for persistence of a population. Habitat characteristics may influence resident bull trout abundance...