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Modeling Relative Effects Of Riparian Cover And Groundwater Inflow On Stream Temperature In Lowland Whatcom County, Washington, Sarah Harper-Smith
Modeling Relative Effects Of Riparian Cover And Groundwater Inflow On Stream Temperature In Lowland Whatcom County, Washington, Sarah Harper-Smith
WWU Graduate School Collection
Many Pacific Northwest streams have water temperatures that exceed thermal thresholds for salmonids. Supporting and maintaining streams with temperatures below these thermal thresholds requires an understanding of the relationships between the main factors influencing stream temperatures. This study examined the relative effects of two of these factors, riparian canopy cover and groundwater inflow, on stream temperatures at the reach scale. I measured stream temperature, net groundwater exchange, and riparian canopy cover levels in 10 different study reaches designed to comprise a factorial combination of reaches with vegetated and unvegetated riparian buffers, as well as gaining and not-gaining groundwater. I then …
Growth And Grazing Of Microzooplankton In Response To The Harmful Alga Heterosigma Akashiwo In Prey Mixtures, Sylvia Lynne Graham
Growth And Grazing Of Microzooplankton In Response To The Harmful Alga Heterosigma Akashiwo In Prey Mixtures, Sylvia Lynne Graham
WWU Graduate School Collection
Heterosigma akashiwo is one of the most ichthyotoxic species of phytoplankton, severely impacting marine ecosystems and economies worldwide. Microzooplankton may play a role in regulating blooms of this alga. This study tested the effects of H. akashiwo, when part of a mixed-prey assemblage, on the growth and feeding of microzooplankton. A saturating prey concentration of 200 μg C l-1 was determined for three ciliate species: Favella sp., Strombidinopsis acuminatum, and Metacylis sp. This was used as the total prey concentration for dual-prey experiments in which the three ciliate species were exposed to reciprocal concentrations of H. akashiwo and a beneficial …
Food Habits Of Harbor Seals (Phoca Vitulina) In Two Estuaries In Northern Puget Sound, Washington, Kathryn Luxa
Food Habits Of Harbor Seals (Phoca Vitulina) In Two Estuaries In Northern Puget Sound, Washington, Kathryn Luxa
WWU Graduate School Collection
There is a long-held belief that marine mammals are a threat to fishery resources. In Puget Sound, there is particular concern about the potential impacts of pinniped predation on depleted or recovering populations of rocky reef bottomfish. To understand the potential effects of pinnipeds on fish stocks, it is necessary first to describe the types of prey that they consume. The goal of this study was to describe the seasonal diet composition of the Pacific harbor seal (Phoca vitulina) in two estuaries, Padilla Bay and Drayton Harbor. Fecal samples ("scats") were collected from haul-out sites during pre-pupping (May - June) …
Movements And Home Ranges Of Harbor Seals (Phoca Vitulina) In The Inland Waters Of The Pacific Northwest, Sarah E. Hardee
Movements And Home Ranges Of Harbor Seals (Phoca Vitulina) In The Inland Waters Of The Pacific Northwest, Sarah E. Hardee
WWU Graduate School Collection
Marine resources are under increasing human pressure and conservation managers are using tools such as marine reserves to increase target fish stocks. However, marine predators may respond to the resultant changes in fish abundance. Harbor seals, Phoca vitulina, are abundant marine predators in the inland waters of the Pacific Northwest with the potential to influence the recovery of depressed fish stocks, yet relatively little is known about their movement patterns and home range sizes in the region. To describe harbor seal behavior, I deployed satellite and time-depth recorder tags during April and May 2007 on 20 individuals at three haul-out …
The Evolution Of Mating Cues In A Beetle Hybrid Zone: Causes Of Geographic Variation In Cuticular Hydrocarbon Profiles, Rachel M.S. Zack
The Evolution Of Mating Cues In A Beetle Hybrid Zone: Causes Of Geographic Variation In Cuticular Hydrocarbon Profiles, Rachel M.S. Zack
WWU Graduate School Collection
The reinforcement of pre-mating barriers in a hybrid zone often leads to reproductive character displacement. However, it can be difficult to link evidence for reproductive character displacement with specific traits important to mate choice. I analyzed the cuticular hydrocarbon (CHC) profiles of Chrysochus cobaltinus and C. auratus to assess whether these pheromones are responsible for the previously observed pattern of reproductive character displacement in the Chrysochus hybrid zone. I found significant CHC divergence between the species, but overall CHC divergence was not higher among hybrid zone populations. However, CHC profiles of sympatric C. cobaltinus were more homogenous and were significantly …
The Dm Gene Family In The Parasitoid Wasp Nasonia Vitripennis: Identification Of A Sex-Specific Homolog Of The Doublesex Gene, Megan Riddle
The Dm Gene Family In The Parasitoid Wasp Nasonia Vitripennis: Identification Of A Sex-Specific Homolog Of The Doublesex Gene, Megan Riddle
WWU Graduate School Collection
Sexual dimorphism is the result of a cascade of genes that triggers sex-specific development. The cascade begins with a primary signal that affects a hierarchy of genes and, through their selective activation and repression, results in the development of an individual of a particular sex. The genes in this regulatory hierarchy are very divergent, with little conservation across taxa. However, homologs of doublesex, a master regulator in the sexdetermining cascade of Drosophila melanogaster, have been found in organisms ranging from nematodes to humans. These homologs are identified by the DM domain, a DNAbinding motif found in genes that function as …