Variations in ocean conditions influenced by climate fluctuations may impact fish populations by changing their spatial distribution, physiology, survival, and other ecological features. Somatic growth is a crucial aspect of the biology of fishes and an important contributor to biomass fluctuations. Climate variability also affects somatic growth rates along the...
Greenland halibut (Reinhardtius hippoglossoides) have decreased in the eastern Bering Sea and Aleutian Islands since the 1970s. The reasons behind the poor recruitment are unknown, and important knowledge gaps of the ecology of the early life stages have been identified. The objectives of thesis research were (1) to examine geographic...
Changes in ocean conditions influenced by climatic fluctuations have lead to changes in individual species distributions, which alter the diversity, communities and species interactions across marine ecosystems worldwide. Assessing the species composition and identifying regions and habitats that can safeguard the persistence of biota are critically important. In this dissertation,...
North Pacific albacore (Thunnus alalunga) is a highly migratory and
commercially valuable species of tuna. All stock assessments and management
decisions for North Pacific albacore are presently based on the assumption of a single,
uniform stock. However, a growing body of evidence from diverse sources suggests
that there are two...
Lagrangian particle tracking (LPT) models are used to explore how physical processes influence the transport of particles (e.g., eggs, larvae, or propagules) in the ocean. On the Oregon continental shelf and slope, the Northern California Current System (CCS) is influenced by spatially and temporally variable coastal currents driven by weather,...
Project CROOS, Collaborative Research on Oregon Ocean Salmon, is a unique partnership of scientists and commercial fishermen that combines catch location data with stock assignments obtained from genetic micro-satellite analysis to investigate the distribution of Oregon Chinook across multiple spatial scales. Using catch data collected by collaborating Oregon troll fishermen,...
The Pacific coast groundfish fishery is a diverse, important and lucrative commercial and recreational fishery. Part of this fishery’s monitoring process includes regular fishery-independent surveys for stock assessment. Although these fishery-independent surveys are cost-effective, they are susceptible to scientific uncertainty, and they do not currently sample in nearshore (water depth...
Oregon’s Coastal nearshore ecosystems are a nexus between living marine resources and coincident human recreational, industrial and socio-economic development. These nearshore regions also provide habitats vital to early life history stages of commercial non-whiting groundfish species, which supplied 21% of the Oregon fishing economy in 2018. The very shallow portions...
The commercial groundfish fishing industry and groundfish research have a long concurrent history of activity on the Oregon continental margin. Within the non-whiting groundfish fishery, the target species are primarily flatfishes, sablefish, lingcod, and rockfishes, though landings of each have fluctuated over time. Recent work shows that over the past...
Pacific cod (Gadus macrocephalus) is an important species, both economically and ecologically in the Bering Sea and Aleutian Islands (BSAI). However, little is known about its spawning dynamics. To address this knowledge gap, I developed a gross anatomical maturity key for Pacific cod to assess temporal and spatial patterns of...