Predicting recruitment, which is dependent on parent stock size and climate, is vital for forecasting productivity of fish stocks. The effects of climate can be analyzed via the use of climate indices. Three climate indices, the Pacific Decadal Oscillation, the North Pacific Gyre Oscillation, and the Oceanic Niño Index, describe...
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...
Nearshore hypoxia within the Northern California Current (NCC) system is a seasonal phenomenon caused by coastal upwelling and occurs mainly during late-summer and early fall. The effects of low oxygen levels on fish and invertebrate communities, particularly during early-life history stages, however, are poorly known for this area. I investigated...
In the past two decades, occurrences of summertime upwelling-driven low dissolved oxygen (DO) events, or hypoxia, have increased along the northeast Pacific coast. If hypoxic events are severe enough to cause marine species mortality, the areas affected are often called "dead zones." In 2002 and again in 2006, the events...
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Lorenzo Ciannelli
In the past two decades, occurrences of summertime upwelling-driven low
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...
Early life stages of marine fishes exert substantial control on the productivity and resilience of marine fisheries, as these life stages represent periods of extreme mortality. Additionally, eggs and larvae of marine fishes respond rapidly to environmental change and can thus be used to infer ecosystem-wide responses to climate change...
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...
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,...
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...
This study investigated long-term (1961-2008) changes in albacore (Thunnus alalunga) abundance and distribution in relation to local environmental and large-scale climate indices in the Northeastern Pacific using time series and spatial analyses. Prior to the time series analysis, a wavelet analysis was conducted to examine nonrandom patterns of cyclical variability...
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Lorenzo Ciannelli
This study investigated long-term (1961-2008) changes in albacore