OIMB Theses

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https://hdl.handle.net/1794/1044

This collection contains some of the theses and dissertations produced by students in the University of Oregon OIMB Graduate Program. Paper copies of these and other dissertations and theses are available through the UO Libraries.

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Now showing 1 - 20 of 80

Open Access
THE LARVAE DYNAMICS OF CANCER MAGISTER IN THE COOS BAY ESTUARY
(2022-07-06) Rowell, David
The role of an estuary or bay in the life cycle of Cancer magister is not well understood. I believe Coos Bay, as well as other bays, is an important "nursery" ground for young crabs, its recruits are necessary for sustaining a commercial fishery. Tasto (1978) has shown that juveniles account for a larger percentage of an estuary's crab population than in nearshore waters. The juveniles in the S.F. Bay-complex exhibited a growth rate nearly twice that of ocean-reared crabs (Tasto et al 1981). It is postulated that this is due to reduced predation pressure and increased food supply within the estuary.
Open Access
Predicted response of eelgrass (Zostera marina L.) photosynthesis, growth, and survival to ocean acidification
(2009-07-30) Morgan, Erin
Over the past 250 years, the composition of Earth's atmosphere has changed as a result of anthropogenic emissions of greenhouse gases. For example, activities such as deforestation, agriculture, and the burning of fossil fuels have produced a 31% increase in the concentration of atmospheric carbon dioxide ([CO2]) since 1750 (IPCC 2001). Earth's atmosphere is linked to the oceans at the sea surface, such that alterations in atmospheric composition are reflected in the water. In particular, atmospheric CO2 exists in equilibrium with dissolved CO2 (CO2(aq)) in the oceans. As the atmospheric [CO2] increases, gas exchange with the oceans causes a concomitant increase in [CO2(aq)], with concentrations rising toward a new equilibrium value (Goudriaan 1993, Guinotte and Fabry 2008).
Open Access
The Effects of Mammalian Predators on a Southern Oregon Colony of Leach's Storm- Petrels (Oceanodroma leucorhoa)
(University of Oregon, 2008-12) Pollard, Anne M. (Anne Marie), 1984-
Saddle Rock, with an estimated 86,300 birds, was the third largest colony of Leach's Storm-petrels (Oceanodroma leucorhoa) in Oregon in 1988. This colony is uniquely vulnerable to terrestrial predation due to its contiguity with the mainland during low tides. In recent years, an increase in visitation of raccoons and river otters to Saddle Rock has resulted in increased bird mortality. In 2007 I estimated predation rates ranging from 0 to 59 birds per night, with predation occurring on 7 of 11 nights checked. 48% of marked burrows were depredated throughout the season. In 2007 and 2008, I monitored nesting density and burrow occupancy rates on Saddle Rock and compared these data with those from nearby Hunters Island, a similarly sized colony. Saddle Rock now hosts significantly lower densities than Hunters Island. Comparisons of recent Saddle Rock data with those from 1979-1995 show a steep population decline.
Open Access
Barnacle Feeding: Comparing Cirral Anatomy, Feeding Behavior, Reynolds Numbers, and Cirral Fan Leakiness Across Three Size Classes of Three Species of Common Acorn Barnacles
(University of Oregon, 2007-12) Geierman, Christina, 1982-
This thesis investigated feeding behavior, cirral anatomy, Reynolds numbers (Re's), and leakiness of the cirral fan for three barnacle species: Balanus glandula, Semibalanus cariosus, and Balanus nubilus. A study of the feeding of B. glandula revealed that newly-metamorphosed juveniles fed at Re's less than one and their cirral fan leakiness was <5% at current speeds of 4 cm/s. At this speed, large and medium individuals fed at Re's near unity, and their cirral fans were 6.8±O.7% leaky. The experiments were repeated using S. cariosus and B. nubilus with the same tissue mass as B. glandula. No clear species-specific or size-specific trends were identified in these species. The observed switch from low to high Re feeding in B. glandula may indicate a lower limit to the size of this species, if further research confirms low Re feeding is less efficient and field current velocities are sufficiently low.
Open Access
Distribution of Zooplankton and Detritus within Langmuir Circulation Cells
(University of Oregon, 2007-12) Laferriere, Alison Mariah, 1976-
Langmuir circulation cells are wind generated surface currents, which take the form of alternating clockwise and counter clockwise rotating helical cells. Models suggest that organisms and particles may be retained in the convergence and divergence zones depending on the relative settling and swimming velocity versus circulation velocity. Surface water in convergence and divergence zones of Langmuir circulations were sampled with plankton nets and zooplankton and fecal pellets were enumerated. Copepods did not differ significantly between zones. Balanus glandula cyprids, competent Polydora spp., and an unidentified late stage veliger were often significantly concentrated in convergence zones. These results suggest that late stage larvae may be exploiting Langmuir circulation as a transport mechanism to travel shoreward for settlement. Fecal pellets were more concentrated in divergence zones on four out of six sample days. On the two days when pellets were more concentrated in convergence zones the swell was larger.
Open Access
Review of factors contributing to the settlement and recruitment of barnacles
(2007-03) Trainer, James
Barnacles are popular study organisms for a variety of reasons. As adults, they are sessile, and they are often small and numerous, making them easy to manipulate in ecological experiments. A researcher can be sure that an adult barnacle that disappears between observations has died, and has not moved away. As larvae, they develop through a series of six naupliar instars in the plankton. Nauplii are easy to identify in plankton samples, and are easy to collect from the egg lamellae of adult barnacles and culture in the laboratory. Nauplii metamorphose into the non-feeding cyprid stage, at which point they attempt to contact and stick to hard substrata. Depending on condition of the substrate, cyprids metamorphose into juvenile barnacles or return to the water column. A juvenile barnacle feeds and grows at its site of metamorphosis until it dies.
Open Access
Colonial Ascidian Dispersal: What are the effects of adult population density and isolation on recruitment?
(2007) Braudrick, Nate
Invasive species are thought to be one of the largest ecological threats to healthy ecosystems today. This paper is an attempt to show how anthropogenic transport of species with short dispersal distances is the most important factor in their colonization of new areas. In the Charleston, Oregon marina three study sites were set up to attempt to show the significance of isolation and adult population density on the recruitment of colonial ascidians, an encrusting member of the fouling community. Significant results were found supporting the hypothesis that greater adult population density results in increased recruitment. The second hypothesis of isolation decreasing the recruitment of colonial ascidians was not supported with significant results.
Open Access
Experimental harvests of macroalgae along the Oregon coast with an analysis of associated epiphytic diatom communities
(Thesis (M.S.)--University of Oregon, 2003., 2003) Young, John J.
Open Access
Microbial ecology of South Slough sediments : community composition of bacteria and patterns of occurrence
(Thesis (Ph. D.)--University of Oregon, 2003., 2003) Milbrandt, Eric Charles
Open Access
A CRITICAL REVIEW OF HOMING AND FORAGING BEHAVIOR IN LIMPETS (MOLLUSCA; GASTROPODA} : A CENTURY OF OBSERVATIONS , EXPERIMENTS , AND CONTROVERSIES (1894 TO 2001)
(2002-12) April, Jane Wright
Homing limpets are characterized by their predictable stationary resting behavior in their home territory during periods of inactivity, followed by active feeding excursions ranging up to a few meters away from home . They almost always return to their previous resting spot (home scar) during a tidal cycle. Limpets are grazers that use their radula to scrape and feed upon microalgae, macroalgal settlers, bacteria, cyanobacteria, diatoms and other phytoplankton, and animal larva that settle inside their grazing grounds, called the feeding arena. Home scars lie within the feeding arena and vary according to species . Most limpets live on rock, some live on macroalgal fronds, and some even live on the shells of other gastropods. Some home scars are visible as a chiseled indentation in rock that fits the shape of the limpet's shell perfectly. This depression is caused by the repeated scraping of the returning limpet's shell at the home scar. Other homing limpets do not make a strict scar, rather, they home to a region rather than a spot. Certain homing limpets will join clusters of conspecifics, returning to roughly the same position within the cluster from day to day.
Open Access
Molecular embryology of a larvacean urochordate, Oikopleura dioica, and the origin of chordate innovations
(Thesis (Ph. D.)--University of Oregon, 2002., 2002) Bassham, Susan Lee
Open Access
Transport of zooplankton in South Slough, Oregon
(Thesis (M.S.)--University of Oregon, 2002., 2002) Puls, Amy L.
Open Access
HAUL-OUT AREA USEAGE BY HARBOR SEALS (PHOCA VITULINA) AT THE NORTH COVE OF CAPE ARAGO, OREGON
(2001-04) Cohnstaedt, Lee William
Harbor seals were observed on 70 occasions from 7 April to 10 August, 2001, at the North Cove, Cape Arago, Oregon, to determine if the harbor seals used different haulout zones within the haul-out area during different life history stages. This study identified sex and age as the most important factors influencing the selection of haul-out zones. A haul-out pattern was observed on days when both low tides occurred during daylight hours: the number of animals hauled-out during a morning low tide was fewer than those during the afternoon low tide regardless of weather conditions.
Open Access
Nearshore topographic fronts : their effect on larval settlement and dispersal at Sunset Bay, Oregon
(Thesis (M.S.)--University of Oregon, 2001., 2001) McCulloch, Anita
Open Access
The relationship between structural and functional polymorphism of the hemocyanin of the red rock crab Cancer productus
(Thesis (M.S.)--University of Oregon, 2001., 2001) German, Jennifer Ann
Open Access
THE EFFECT OF UV RADIATION ON CYANOBACTERIAL MAT COMMUNITY STRUCTURE
(2000-06) Inman, Carrie Elise
Cyanobacteria are thought to have evolved during the early Precambrian, 2.5-3.8 billion years ago, when there were very high levels of UV radiation reaching the Earth's surface due to a lack of absorbing gases int he atmosphere. Oxygenic cyanobacteria were one of the few photosynthetic organisms that could survive under these harsh conditions. Cyanobacteria today have also been found to employ UV tolerant strategies to cope with the damaging effects of UV radiation. In this study three cyanobacterial mats were investigated to determine if UV had an effect on the mats in the field and subsequently on clonal isolates cultured from these mats in the lab. UV exclusion experiments, using UV blocking and UV transmitting filters, were carried out in the field over a two-month period. Protein and pigment analysis on the core samples collected from the field UV treatments showed no significant difference between the treatments. However, samples collected of new settlement cell material on ceramic tiles, did show a significant different between the two UV treatments. UV exclusion experiments run using two strains of clonal isolates of Lebtolyngbya sp. cultured from Mushroom Spring did show a highly significant detrimental effect of UV on growth measured by dry weights. In addition, the two strains, one cultured from the UV(-) field material and one cultured from the UV(+) material, were effected differently by UV radiation in the lab UV exclusion experiment. The isolate cultured from the UV(+) mat material was less effected by UV radiation, as measured by dry weight accumulation over time. This may imply the use of a unique UV tolerant strategy employed by this strain.
Open Access
How successful has wetland mitigation been? : an examination of wetland compensatory mitigation success in the Coos Watershed, Oregon
(Thesis (M.S.)--University of Oregon, 1999., 1999) Shaffer, Laura Jean, 1972-
Open Access
PACIFIC NORTHWEST COASTAL TEMPERATURES: INVESTIGATION OF INTERDECADAL CYCLES AND BIOLOGICAL IMPLICATIONS
(1998-06) Shotwell, Kalei
Investigations regarding interdecadal climate cycles have surged in the past several years providing alternative perspectives into the forcings on climate change. The possible couplings between the various patterns of these physical processes (oceanic, atmospheric), terrestrial, and biosphere regimes are of substantial importance. This study seeks to explore the relationship between the ocean and the land-surface on a regional scale. It is hypothesized that Pacific Northwest coastal sea surface temperatures and surface-air temperatures are temporally identical, or merely offset by a time lag, with the same pattern and period. Correlation and regression analysis were completed for the chosen sites, and significant positive correlation (r: 0.843) was determined. The similar cycles of the marine and terrestrial environments have significant biological implications. The progress with and problems of biological climate patterns is discussed along with the importance of proxy indicators, and relevancy to fisheries and management.
Open Access
Spatial and temporal variation in the development of epiphytic diatom communities on the eelgrass, Zostera marina L.
(Thesis (M.S.)--University of Oregon, 1998., 1998) Mutchler, Troy R.
Open Access
Transport mechanisms of decapod larvae to the nearshore and estuarine environment
(Thesis (M.S.)--University of Oregon, 1998., 1998) Johnson, Jeremiah