Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 208-216). Description: xiv, 216 leaves : maps ; 29 cm.

Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 42-46).

Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 283-301). Description: xxx, 301 leaves : ill. ; 29 cm.

xiv, 154 p. : ill. A print copy of this title is available through the UO Libraries. Search the library catalog for the location and call number. / The polychaete worm Owenia collaris (Family Oweniidae) is found in soft sediment habitats along the northeastern Pacific coast, particularly within bays and estuaries. Seasonally, these small tubeworms spawn gametes freely into the water column where they develop into planktotrophic mitraria larvae. After three to four weeks at ambient temperatures, they undergo a dramatic metamorphosis and return to the bottom. The reproductive and larval biology of a population of O. collaris in Coos Bay, OR was investigated over several years. The development of this polychaete has several unusual features, including a stomodeum not derived from the blastopore and continued proliferation of trochoblast descendents, producing simple cilia on monociliated cells. The description of larval and juvenile structures provided morphological characteristics useful for distinguishing this species from the congener O. fusiformis . The consequences of the unusual larval morphology of O. collaris (i.e. simple cilia, convoluted ciliated band) were investigated by comparing the feeding performance and growth of this species with those of invertebrate larvae representative of the more typical tornaria-type larval forms found in deuterostomes and trochophore-type larval forms found in the lophotrochozoa. Feeding and growth patterns were similar in the convergent mitraria and deuterostome larval forms. In an experiment designed to test the relationship between abiotic factors and the seasonal reproduction, the onset of breeding was cued by photoperiod, but seasonal trends in temperature, alkalinity, food availability for larvae, and salinity may drive reproductive patterns as well. Within the Coos Bay estuary, the intertidal distribution of O. collaris is related to adult salinity tolerances. Low salinity limits horizontal distribution and also reduces potential for reproduction. Most life-history stages are tolerant of a wide range of temperatures, both higher and lower than those typically seen in Coos Bay. There is little evidence to support the hypothesis that sediment characteristics limit distribution within the bay, although settling juveniles show some preference for small grain sizes and may not be able to recruit to mudflats that completely lack these size fractions.

xi, 134 leaves : ill. ; 28 cm Notes Typescript Thesis (M.A.)--University of Oregon Includes vita and abstract Bibliography: leaves 130-134 Another copy on microfilm is located in Archives

vii, 97 leaves : ill., maps ; 28 cm Notes Typescript Thesis (M.S.)--University of Oregon, 1985 Includes vita and abstract Bibliography: leaves 92-97 Another copy on microfilm is located in Archives

ix, 62 leaves : ill. ; 29 cm Notes Typescript Thesis (M.S.)--University of Oregon, 1987 Includes vita and abstract Bibliography: leaves 59-62 Another copy on microfilm is located in Archives

Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 45-47). / Rhithropanopeus harrisii is an introduced Atlantic crab in Coos Bay, Oregon. In Coos Bay, it occurs only in the uppermost estuary where salinities are seasonally low (<1 0/00). Rhithropanopeus occurs at higher salinities in its native range, and tolerates higher salinities in the laboratory. A native crab, Hemigrapsus oregoneos1s, occurs in the estuary, but not as far up into the oligohaline and freshwater zones as Rb1tbcopanopeus. In laboratory experiments, adult Hem1grapsus consume juvenile Rhithropanopeus. Hemjgrapsus is significantly more aggressive than Rhithropanopeus. The absence of juvenile Rhithropanopeus at field sites where both species occur suggests that field interactions may be occurring. Taken together, these results and observations suggest that there may be a dynamic zone in the estuary where the distribution of Rhithropanopeus is restricted by Heroigrapsus. Rhithropanopeus may find a refuge from Hemigrapsus in the oligohaline-freshwater Zones of the estuary, such that Hemigrapsus may be exerting selective pressure on the Rhithropanopeus population favoring freshwater adapted individuals.

Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 84-88). Description: x, 88 leaves : ill. ; 29 cm. / Along the Oregon coast blooms of Pseudo-nitzschia spp. have been an almost annual occurrence since monitoring began in the late 80's. This study looks at the distribution of Pseudo-nitzschia spp., in relation to meteorological and oceanographic conditions. A series of transects (1995-98) were done in Coos Bay and over the adjacent continental shelf under a variety of oceanographic conditions. An intense sampling program was undertaken in June 1998, with simultaneous nearshore and in bay (Coos Bay) sampling, including a nearshore grid, 24 hour anchor station in the bay, and an in bay incoming tide drift study. The results suggest that blooms develop nearshore after upwelling events. In conditions of relaxed upwelling highest cell concentrations were found immediately adjacent to the coast in surface and mid-depth waters. At stations in Coos Bay, Pseudonitzschia spp. concentrations increased with the incoming tide. Nearshore phytoplankton populations were transported into the bay, initially in the more saline bottom waters, but were rapidly mixed throughout the water column by the turbulent flow in the channels. On ebbing tides there was a reduced number of phytoplankton in the water column, possibly indicating consumption by in bay filter feeders or sinking and deposition on the bottom.

The Olympia oyster, Ostrea lurida. was overharvested in the early 20th century and is now the focus of restoration efforts in estuaries along the west coast of North America. These efforts would be aided by a better understanding of larval abundance patterns, settlement behavior, and post-settlement performance of oysters in estuaries throughout its range. In Coos Bay, Oregon, all three of these components of the oyster life cycle were investigated at multiple sites. Like adult oysters, larvae were restricted to the upper portion of the bay, although larvae were supplied to sites in the upper bay where settlement was low. Settlement and post-settlement growth was highest at sites of high adult density. These results indicate that in O. lurida, as in many other marine invertebrates, the adult population is subject to bottlenecks at the larval and juvenile stage that can vary spatially. This thesis contains previously unpublished co-authored material. / 2014-12-16