A new method for encapsulating low-molecular weight, water-soluble substances in lipid-walled microcapsules (LWMs) for delivery to marine bivalves was developed, characterized, and tested. LWMs produced by a spray technique (spray microcapsules, SMs) were demonstrated to encapsulate both aqueous (polymeric dye or oxytetracycline hydrochloride) and particulate (riboflavin) core materials within a...
The effects of harvesting Pacific hake (Merluccius productus)
were examined with a multi-species numerical model composed of
seven logistic growth equations coupled by a food web. The
food web was composed of: California sea lions (Zalophus
californianus), hake, sablefish (Anaplopoma fimbria), spiny
dogfish (Squalus acanthias), a generic rockfish species
(Sebastes...
The Sultanate of Oman has 1700 km of coastline extending from the Arabian Gulf
south to the Arabian Sea. The demersal fish distributions and assemblages have not previously
been well defined. In winter, variations in the oceanography of the area are minimal. In
summer, however, the Arabian Sea is strongly...
This study examined features of deep pool (>0.8 m mean depth) used by
adult summer steelhead in Steamboat Creek (1991-1992). Steamboat Creek had
a heterogenous thermal profile, with some segments exceeding preferred
temperature of steelhead. Deep pools were scarce (4% of the total habitat units)
and 39% of them were...
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...
The microsporidian parasite Nadelspora canceri infects Dungeness crabs, Cancer magister, along the United States Pacific Northwest coast. The prevalence and seasonal variation of N. canceri in Dungeness crabs from Alsea Bay, Oregon, are described based on examination of 2991 crabs collected at monthly intervals from October, 1991 to June, 1993....
This study examined channel structure and position and riparian
vegetation and land use on the upper 70 km of the McKenzie River, Oregon in
the 1940s, compared the 1940s conditions to present conditions, and explored
the processes driving change in this system and the implications for aquatic
habitat. The hydrologic...
Distribution and juvenile habitat use of bull trout (Salvelinus
confluentus) were surveyed in selected areas of the Upper Willamette,
Deschutes, upper Yakima, and upper Cedar River basins in Oregon and
Washington from 1989 to 1991, using day snorkeling, night snorkeling,
and electrofishing. These methods were selected after a preliminary
diel...
Ten high mountain ponds in Mount Rainier National Park, Washington State, were
studied from June through September 1992 to investigate the influences of fluctuating
pond volumes on zooplankton communities. A temporary pond of short wet phase
duration was inhabited by zooplankton taxa with short generation times and a crustacean
taxa...
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...
Genetic differences between early and late forms of
Alaskan chinook salmon (Oncorhynchus tshawytscha) were
identified using two genetic approaches: mitochondrial
DNA (mtDNA) analysis and protein electrophoresis. The
study populations consisted of early- and late-run chinook
salmon in each of the Kenai and Kasilof rivers in Alaska,
and a single population...