Understanding the ecological role of Pacific oyster aquaculture (Crassostrea gigas) and eelgrass (Zostera marina L.) as important habitats in US Pacific Northwest estuaries is critical for management and regulatory decisions. The oyster aquaculture industry is currently restricted by regulations concerning impacts of their activities on Z. marina. This seagrass is...
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,...
Invasive species are a growing global economic and ecological problem. Invasive Indo-Pacific lionfish (Pterois spp.) are known to have extreme negative effects on coral-reef communities in the Bahamas, so understating their distribution within and among reefs, what limits their local movements, and the effects they have on native prey species...
Marine heatwaves (“MHWs”) are discrete periods of anomalously warm ocean conditions that can lead to shifts in the distribution and abundance of marine organisms. Low-trophic level, pelagic forage species are frequently among those affected by MHWs, often resulting in considerable impacts upon their predators. In the North Atlantic Ocean, Atlantic...
Efficient foraging strategies result in a predator spatially overlapping with its prey, foraging in the most profitable patches, and minimizing the time transiting between patches. Previous studies investigating baleen whale foraging strategies have generally focused on investigating spatial overlap with prey patches, patch profitability or movement within feeding grounds. The...
Monitoring marine ambient sound using standardized methods supports assessments of ocean sound levels across widespread ecosystems. This thesis quantifies differences among coastal and deep-water marine soundscapes in the Atlantic and Pacific oceans. The sources of sound in a soundscape are compartmentalized into three components and compared over time and among...
Passive acoustic monitoring is a valuable tool for observing the status of marine environments. Comparisons of underwater soundscapes over temporal and spatial scales can provide data to inform marine conservation efforts, including protection of threatened and endangered species. This dissertation utilizes passive acoustic data collected via a broadly spaced array...
Year-round habitat use of marine predators provides knowledge of important marine areas throughout different life stages. Large-scale, environmental variability, both in space and time, causes changes in the behavior and distribution of marine predators that are important to quantify for conservation. In the Northern California Current System (NCCS), common murres...
Pacific harbor seals (Phoca vitulina richardii) are one of Oregon’s most common coastal predators, numbering between 10,000 and 12,000 individuals (Brown et al. 2005b). They consume more than 149 species or types of marine prey within the Pacific Northwest, which include a large variety of commercially important fisheries species. Despite...
Understanding prey quality and prey selection by predators is critical for management efforts aimed at identification and protection of essential habitats and prey. Marine predators must make daily foraging choices in a heterogenous and dynamic environment in order to meet the high energetic demands of migration, reproduction and foraging. With...