An empirical statistical model is developed that relates the non-tidal motion of the ocean surface currents off the Oregon coast to forecasts of the coastal winds. The empirical statistical model is then used to produce predictions of the surface currents that are evaluated for their agreement with measured currents. Measurements...
Inner-shelf circulation and mechanisms of across-shelf transport of water masses were examined using seven years of observations collected by the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) program, a long-term monitoring effort along the central Oregon coast. Since 1998, moored velocity and hydrographic measurements have been obtained during the...
The Oregon continental shelf waters are typically characterized by four to five major upwelling events that occur between May and October. The upwelled water is rich in nutrients, which fuels an increase in phytoplankton biomass. The onset of El Nino, however, can disrupt the normal physical processes along the Oregon...
This thesis investigates the behavior of major inorganic nutrients (P, N, Si), trace metals (Mn, Fe), and alkaline-earth metals (Ba) within Tillamook Bay over seasonal cycles and under a range of river discharge conditions from October 1997 through December 1999. Located in the Pacific Northwest region, Tillamook Bay is an...
Fifty-two one-meter plankton net samples from four stations off Newport, Oregon, were examined for composition and abundance of euphausiids and copepods. They provided data on dominance, species associations and environmental relationships. The euphausiid-copepod population off Oregon is composed of 12 numerically dominant species. These species occurred in most of the...
The copepod population in Oregon coastal waters was examined from 116 oblique plankton tows taken during 1962. Quantitative Clarke-
Bumpus samplers were used and stations ranged from 5-105 miles from shore along four hydrographic lines. Forty-six species of copepods were identified. The total adult population varied according to distance from...
A series of factorial experiments were conducted using eyed oyster larvae (Crassostrea gigas) reared at a commercial hatchery in Netarts, Oregon. The objectives of the study were to obtain the highest percentage of setting larvae and the best survival of the spat. Experiments on the combined effects of temperature and...
Euphausiids constituted the major food of five co-occuring species of rockfishes (Sebastes spp.). Copepods, decapods, cephalopods, amphipods, fishes and other pelagic prey were also consumed but were
less important to the overall diet. Two species, S. flavidus and S. diploproa, were relatively euryphagous, utilizing a high number of prey taxa....
An investigation has been made of several physical parameters of the effluent plume of the Columbia River as it enters the Pacific
Ocean. Radioactive material in trace amounts enters the Columbia River from the Hanford nuclear reactors at Richland, Washington. One of these nuclides, chromium -51, has been used to...
Past studies of the Oregon and Washington coast have shown a rapid change in the coastal ocean conditions with the onset of upwelling in spring. This process, called the spring transition marks the change from winter to summer conditions along the west coast of Unites States. To examine the interannual...
Field and laboratory work was undertaken in 1993 to increase understanding of the life history and ecology of the brown jellyfish,
Chrysaora fuscescens, a large semaeostome typically abundant in the neritic regions of the Oregon coast during summer months. Few
medusae were found during 1993, possibly the result of anomalous...
Netarts Bay is a coastal lagoon on the northern Oregon coast. Four major sedimentary environments are recognized including channel, sand flats, mud flats, and marsh. Fine-grained sediment is carried in by streams and deposited in the marshes and mud flats. Fine sand for the channel and sand flats is derived...
Based on the principle that the history of a discipline is important to the discipline itself, this thesis devotes two chapters to ROBERT HOOKE AND THE FOUNDATION OF GEOLOGY and two chapters to modern geology, viz. THE TECTONIC EVOLUTION OF THE OREGON CONTINENTAL MARGIN. The first part of this abstract...
The claw shuddering display of the shore crab Hemigrapsus oregonensis was explored with acoustic and behavioral observations. Male H.
oreqonensis stridulate during claw shuddering display. The stridulatory apparatus is present only on the males. The acoustic signal was of brief duration, showed a general pattern of sound bursts, but varied...
The Antarctic Ocean during the Cenozoic experienced four periods of increased surface productivity: the Middle Eocene; the beginning of the Miocene; the Middle Miocene; and near the Miocene-Pliocene boundary. The fourth increase in productivity began five
million years ago and has since progressively increased to the present level of intense...
The extent and mechanism of energy dissipation has been studied in Coos Bay, a coastal plain estuary. Coos Bay is located on the central Oregon coast, 184 nautical
miles south of Astoria, Oregon, and 35 nautical miles north of Cape Blanco. Past field work in Coos Bay and data obtained...
Northern sea lions (Eumetopias lubatus) were studied at three sites (Rogue Reef, Oregon, Marmot Island, Alaska, and T.Ugamak Island,
Alaska) during the 1982, 1983, 1985, and 1986 breeding seasons. Data were collected on female activity budgets, attendance patterns, births, copulations, population structure, and patterns of seasonal and daily abundance. Females...
Number of harbor seals, counted on 32 haul-out areas in Oregon, increased by 6 - 8.8 % per year from 1975 - 1983. Percent of seals in bays has increased an average 1.8%/year, from 47% in 1975 to 61% in 1983. Along the central Oregon coast, harbor seals were most...
Plankton and surface sediment samples from the Gulf of California
were analyzed to determine the present geographic distribution of silicoflagellate
species in this area. Variations in the composition of the
silicoflagellate assemblage are related to water mass distributions.
Seven species and three forms were identified in these samples. Octactis
pulchra...
We sharpen our view of an eastern boundary current region during
the upwelling season through the analysis of several data sets.
We focus on the mesoscale flow field off of northern California,
observed during the Coastal Transition Zone (CTZ) experiment of 1988.
First, we estimate tidal currents in the region...