The use of omics for disease evaluation in the brains of marine mammals

Marine mammals are top predators that are essential for the health and function of our oceans. These top predators are often affected by various factors that can be detrimental to their populations. Therefore, there is a need to evaluate undetermined causes of deaths and to better understand known diseases in marine mammals to mitigate future marine mammal mortality events. In this dissertation, I examined a mortality event that occurred in 2009 and affected seven harbor seals that died from an unknown brain disease.

Seagrasses as Potential Chemical Refugia for Acidification-Sensitive Bivalves

As the effect of ocean acidification (OA) on marine calcifiers is better understood, a range of potential mitigative strategies have been proposed, many of which are plagued by concerns of scale and feasibility. One oft-cited option is to increase the biomass of photosynthetic organisms to remove CO2 from the water column and facilitate organic carbon burial. Seagrasses show much promise in this regard, owing to their highly refractive tissue. Timescales of carbon burial with respect to this strategy are on the order of years to decades.

Quantitative tools for monitoring strategy evaluation and assessment of sea turtle populations

Green sea turtles, Chelonia mydas, have endangered and threatened populations globally, but several populations show signs of population recovery. In Hawaii, nesting female green turtles have increased 5.7% year-1 since 1973, but wide fluctuations in census counts of nesting females make recovery diagnosis difficult.

Spatiotemporal drivers of seabird distribution at the Pacific Marine Energy Center off Newport, Oregon

The central Oregon coast was selected as an ideal site for wave energy development and establishment of the Pacific Marine Energy Center (PMEC). PMEC will consist of two nearshore sites, one north (NETS) and one south (SETS) of the Yaquina River, Oregon. Our study aims to assess how the development of wave energy sites might impact marine birds. We used vessel-based strip transect surveys to detect spatial and temporal patterns of seabirds during 28 surveys of NETS and SETS from 2013-2015.

Genetic Connectivity of Dungeness Crab (Cancer magister) in the California Current System and Puget Sound

Understanding connectivity among exploited populations is critical to their sustainable management and long-term viability. In the marine environment, estimates of connectivity often rely on the use of genetic markers, as dispersal primarily occurs during a planktonic larval phase which is difficult to track using direct methods. In this thesis, we investigated the population genetic structure of the most valuable commercially harvested species on the west coast of the United States, the Dungeness crab (Cancer magister).

Environmental History of Estuarine Dissolved Oxygen Inferred from Trace-Metal Geochemistry and Organic Matter

Environmental history recorded in sediments can track estuarine water quality through the use of geochemical and biological proxies. I collected sediment cores from two locations in the Coos Bay Estuary, at South Slough and Haynes Inlet, spanning from ~1680 AD to the present. To address the historical water column oxygen in the estuary I measured geochemical proxies including organic matter, magnetic susceptibility, and redox-sensitive metals to calibrate against a detailed 15-year record of dissolved oxygen observations.

Agent-based Tsunami Evacuation Model: Life Safety and Network Resilience

Natural disasters could result in unnecessary loss of life and disproportionat​e suffering to families and communities if evacuation plans are not in place or understood by the public. In the Pacific Northwest, a magnitude 9.0 earthquake and tsunami from the Cascadia Subduction Zone (CSZ) represents one of the most pressing natural disasters with an astonishing high 7%-12% chance of occurrence by 2060.

A Landscape-Scale Watershed Assessment Method to Support Fish Passage Restoration in Puget Sound, Washington State: An Analysis for the Fish Barrier Removal Board

In 2014, the Washington State Legislature directed the creation of the Fish Barrier Removal Board (FBRB), a multi-entity committee tasked with the development of a statewide strategy for removing anadromous fish barriers. The strategy shall identify watersheds with the greatest potential for salmon and steelhead recovery and implement the removal of multiple barriers within those watersheds. Prioritizing whole watersheds for barrier removal is a new and untested approach to fish passage restoration in Washington State.

Evaluating coastal protection services associated with restoration management of an endangered shorebird in Oregon, U.S.A.

Coastal sand dunes and beaches offer a variety of ecosystem services such as coastal protection, sand stabilization, species conservation, and recreation. However, the management and balance of ecosystem services offered by dunes and beaches is challenging when ecosystem services interact across the landscape. Management focusing only on one ecosystem service may result in unintended consequences and trade-offs between other key services.

Potential Impacts of Timber Harvesting, Climate, and Conservation on Sediment Accumulation and Dispersal in the South Slough National Estuarine Reserve, Oregon

Accurate sediment flux histories are critical data for deciphering the relative importance of climate and land use factors such as logging and road construction on sediment production and deposition. We use 210Pb activities derived from sediment cores taken on the tidal flats of the South Slough of the Coos Bay estuary to establish temporal variations in sediment accumulation rates. We determined that average deposition varied between 0.4 and 0.81 cm/yr based on two ~80 cm sediment cores.