Continental shelf sediments are sinks for dissolved oxygen and sources of many major and minor nutrients required for oceanic surface primary production, resulting in a strong coupling between benthic and pelagic biogeochemical cycling. However, the influence and spatiotemporal variability of benthic remineralization on bottom-water chemistry and the supply of nutrients...
It is well documented that microplastics and semi-synthetic particles (<5 mm) pervade the marine environment, with their ingestion by marine fauna eliciting global concern. While fishes exposed to microparticles in a laboratory setting have exhibited both sub-lethal and lethal effects, the diversity in material, morphology, and size of these contaminants...
Copper and iron are essential micronutrients that are required by marine primary producers for a variety of metabolic processes. Over 99% of both copper and iron are bound within organic complexes in the marine environment, however the molecular identity of many of these complexes remains unknown. The speciation of these...
Harmful algal blooms (HABs) are a problem for coastal communities, the fishing industry, and coastal organisms. Pseudo-nitzschia spp. is a regularly occurring diatom in Oregon’s coastal waters. At times, Pseudo-nitzschia spp. can facultatively produce domoic acid, a neurotoxin that can bioaccumulate in the food chain. While regular shore-based sampling provides...
As the global demand for seafood increases each year, there is a growing need to expand sustainable aquaculture in the interests of food security and resilience of coastal communities. Pacific oysters, Crassostrea gigas, are grown in West coast estuaries - where cultures often overlap with the federally protected native eelgrass,...
Connectivity of fish populations is a crucial question for fisheries conservation and the development of spatial management plans. Both adult and larval movement define the extent and direction of ecological and evolutionary overlap between geographic regions and, therefore, how we define stocks for management purposes. Within that context, my work...
Pacific razor clams (Siliqua patula) are narrow oblong bivalves that can be found in sandy habitats along the western coast of the United States, from Alaska (Aleutian Islands) to southern California (Pismo Beach). In Washington state, the razor clam fishery has been documented to be an important contributor to the...
Continental margin sediments have been recognized as a major source of dissolved iron to the global ocean. The focus of this study was to build an early diagenetic model that can be used to simulate iron fluxes from continental margins and thereby identify key controlling factors. The model uses the...
Coastal hypoxia, or low oxygen episodes pose a threat to marine resources in the Pacific Northwest. Previous research into nearshore oxygen dynamics have linked coastal upwelling to this seasonally occurring phenomenon, however the manifestation of hypoxic waters over coastal fishing grounds was not well understood. Through a partnership with Dungeness...
The presence of predators and competitors can offer biotic resistance against the establishment of non-native species, including the European green crab, Carcinus maenas, (EGC) in the estuary of Coos Bay, Oregon. It has been suggested that limb loss, or autotomy of the EGC will increase in areas that include populations...
Netarts Bay is a shallow, temperate, tidal lagoon located on the northern coast of Oregon and site of the Whiskey Creek Shellfish Hatchery (WCSH). Data collected with an automated flow-through system installed at WCSH capable of high-resolution (1 Hz) pCO2 and hourly TCO2 measurements, with measurement uncertainties of <2.0% and...
A carefully calibrated primitive-equation model from 41°N to 48°N is used to study the poleward undercurrent off the US west coast. Chapter 2 describes poleward flow over the slope from Eulerian and Lagrangian perspectives. The model is robust, in the sense of several characteristics being qualitatively consistent with observational and...
Modifications of an ocean model are described, as the objective for which the model was used changed to study the kinematics and dynamics of an eastern-boundary poleward undercurrent.
Currently, forecasts produced by the Oregon-Washington (OR-WA) Coastal Ocean Forecast System are constrained by assimilation of only surface observations. The 4-dimensional variational (4DVAR) data assimilation (DA) algorithm is utilized to combine the model and the data, with the time-independent forecast ("background'') error covariance B. In this study, two possible improvements...
Internal waves and tides are a dominant source of current variability, and they are intermittent and hard to predict. Internal waves can have significant variability in alongshore structure. However, previous studies on internal waves have focused primarily on their cross-shore structure and propagation. For example, while alongshore-propagating superinertial internal tides...
Small rivers, such as those that line the Oregon coast, have been shown to deliver significant concentrations of suspended sediments and nutrients to estuaries and the coastal ocean during wet seasons during which winds are predominantly downwelling-favorable. The fate of the buoyant source water and of any suspended or dissolved...
What affects the oceans affects terra firma. Ocean Solutions, Earth Solutions gathers the insights of more than 50 ocean and coastal science researchers exploring ocean components and their relationships, patterns, and trends over time and space. The book's 16 chapters feature geographic information system (GIS) best practices and include additional...
Turbulence controls the composition of river plumes through mixing and alters the plume's trajectory by diffusing its momentum. While believed to play a crucial role in decelerating river-source waters, the turbulence stress in a near-field river plume has not previously been observationally quantified. In this study, finely resolved density, velocity,...
In most estuarine systems it is assumed that the dominant along-channel momentum balance is between the integrated pressure gradient and bed stress. Scaling the amplitude of the estuarine circulation based on this balance has been shown to have predictive skill. However, a number of authors recently highlighted important nonlinear processes...
A reduced-gravity model is presented of the warm-water branch of the middepth meridional overturning circulation in a rectangular basin with a circumpolar connection. The model describes the balance between production of warm water by Ekman advection across the circumpolar current, dissipation of warm water by eddy fluxes southward across the...