The early marine phase following freshwater emigration has been identified as a critical period in salmonid (Oncorhynchus spp.) life history, characterized by high but variable mortality. Consistent with the “growth-mortality” and “bigger-is-better” hypotheses, at least some of the mortality during the critical period appears to be size-dependent – with smaller...
Northern anchovy (Engraulis mordax) are a dominant forage fish in the California Current large marine ecosystem (CCLME). However, little is known about northern anchovy abundance, distribution, age structure, or population fluctuations relative to ocean conditions in the eastern boundary upwelling system off the U.S. West Coast. This thesis includes three...
The transition between freshwater and marine environments is associated with high mortality for juvenile anadromous salmonids, yet little is known about this critical period in many large rivers. To address this deficiency, we investigated the estuarine ecology of juvenile salmonids and their associated fish assemblage in open-water habitats of the...
Large river plumes modify coastal environments and can impact production across multiple trophic levels. From 1999 to 2009, the
assemblages of forage fish, predator fish, and other pelagic nekton were monitored in coastal waters associated with the Columbia
River plume. Surveys were conducted at night to target vertically migrating species,...
We examined variability in growth rate during the larval stage of northern anchovy (Engraulis mordax) in response to physical and biological environmental factors in 2005 and 2006. The onset of spring upwelling was anomalously delayed by 2–3 months until mid-July in 2005; in contrast, spring upwelling in 2006 began as...
Most modeling and statistical approaches encourage simplicity, yet ecological processes are often complex, as they are influenced by numerous dynamic environmental and biological factors. Pacific salmon abundance has been highly variable over the last few decades and most forecasting models have proven inadequate, primarily because of a lack of understanding...
Cytochrome B sequence data (FASTA format) from the paper “Seasonal distribution and environmental associations among late larval and juvenile rockfish (Sebastes spp.) off Oregon and Washington: new insights based on genetics”. The data was generated from a sample of 2534 unknown, field collected late-larval and juvenile rockfishes from the Pacific...
The state of the California Current system (CCS) since spring 2010 has evolved in response to the development of cooler La Nina following the dissipation of the relatively weak and short-lived El Nino event of 2009-2010. The 2009-2010 El Nino appears to have dissipated quite rapidly in early spring 2010,...
Interannual variability of Humboldt squid (Dosidicus gigas) occurrence in the northern California Current System is largely unknown. In Oregon, the distribution of this versatile predator and what is influencing their range expansion from Mexico is poorly understood due to the recent nature of their "invasion" and a lack of monitoring....