Diets of juvenile coho Oncorhynchus kisutch and Chinook O. tshawytscha salmon
are made up primarily of winter-spawning fish taxa in the late-larval and early juvenile stages that
are undersampled in plankton and larger trawl nets. Although we have no direct measure of the
availability of fish prey important to juvenile...
The trophic habits, size and condition of yearling Chinook salmon (Oncorhynchus tshawytscha) caught early in their marine residence were examined during 19 survey years (1981–1985; 1998–2011). Juvenile salmon consumed distinct highly piscivorous diets in cold and warm ocean regimes with major differences between ocean regimes driven by changes in consumption...
Aggregations of the neustonic hydrozoan Velella velella occur periodically in the northern California Current. Despite the regular occurrence of notable bloom events in this productive upwelling zone, little is known about their trophic ecology. We used gut content and stable isotope analyses (SIA) to elucidate V. velella prey selectivity and...
The Fukushima Daiichi power station released
several radionuclides into the Pacific following the March 2011
earthquake and tsunami. A total of 26 Pacific albacore (Thunnus
alalunga) caught off the Pacific Northwest U.S. coast between
2008 and 2012 were analyzed for ¹³⁷Cs and Fukushima-attributed
¹³⁴Cs. Both 2011 (2 of 2) and...
The surface-layer zone, occupying the upper 20 cm of the water column, represents a unique oceanic environment. A diverse assemblage of organisms occupies this zone, either in an obligate or facultative manner (Zaitsev 1970, Hempel and Weikert 1972, Cheng 1975, Peres 1982). Certain animals show morphological or biochemical adaptations to...
In the California Current coastal boundary zone, the spring transition between downwelling and upwelling conditions, along with the fluctuating structure of the Columbia River plume, creates highly dynamic interactions. In this study, we investigated whether the surface distribution of brachyuran larvae and ichthyoplankton would track the dynamics of the Columbia...
This report reviews the state of the California Current System (CCS) between winter 2012 and spring 2013, and includes observations from Washington State to Baja California. During 2012, large-scale climate modes indicated the CCS remained in a cool, productive phase present since 2007. The upwelling season was delayed north of...
The state of the California Current System (CCS)
since spring 2011 has evolved in response to dissipation
of La Niña through spring and summer, resurgence of
cooler La Niña conditions in fall and winter, and finally
a transition towards ENSO-neutral conditions in spring
2012. The resurgence of La Niña was...
Dramatic changes in the physical and biological conditions off Washington and Oregon, USA, have occurred since 1998, including extreme El Niño (warm) and La Niña (cool) years, high and low Columbia River flow years, a major intrusion of subarctic water, and a low oxygen event on the shelf. The occurrence...
The dynamic nature of biological hotspots, while well recognized, is not well understood. We hypothesize that the persistence of hotspots in the northern California Current System (CCS), despite seasonal and annual changes in the nekton community species composition, is related to associations among species and their functional redundancy. To address...