Large rivers represent gateways for the transport of
terrigenous and anthropogenic material to the coastal ocean.
Here we document a ∼700 km2 recirculation or bulge associated
with the Columbia River plume that retains recently discharged
river water sufficiently to create a regional bioreactor.
Fueled by a fluvial nitrate source, this...
Alongshore transport was estimated from the gridded AVISO altimeter data and water level data from NOAA tide gauges (1993–2010) for the northern California Current (NCC) system. The biomass of the cold neritic copepods including Calanus marshallae, Pseudocalanus mimus and Acartia longiremis (dominants in the eastern Bering Sea, coastal Gulf of...
Upwelling in eastern boundary current systems is a primary driver of ecosystem productivity. Typically, peak upwelling occurs during spring and summer, but winter upwelling may also be important to ecosystem functions. In this study, we investigated the hypothesis that winter and spring/summer upwelling, operating through indirect trophic interactions, are important...
Climatic effects in the ocean at the community level are poorly described, yet accurate predictions about ecosystem responses to changing environmental conditions rely on understanding biotic responses in a food-web context to support knowledge about direct biotic responses to the physical environment. Here we conduct time-series analyses with multivariate autoregressive...
Early ocean residence is considered a critical period for juvenile salmon although specific survival mechanisms are often unidentified and may vary by species or life stage. Columbia River spring-run Chinook salmon Oncorhynchus tshawytscha abundance has declined dramatically since the early 1900s. To elucidate mechanisms of early marine survival, we tested...
Euphausiid krill play a critical role in coastal and oceanic food webs, linking primary producers to upper trophic levels. In addition, some species support commercial fisheries worldwide. Despite their ecological importance, the genetics of these important species remain poorly described. To improve our understanding of the genetics of these ecological...
Generalized additive models (GAMs) were used to investigate the relationships between annual recruitment of natural coho salmon (Oncorhynchus kisutch) from Oregon coastal rivers and indices of the physical ocean environment. Nine indices were examined, ranging from large-scale ocean indicators, e.g., Pacific Decadal Oscillation (PDO), to indicators of the local ecosystem...
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...
The synchrony between coastal and shelf-slope copepod communities was investigated in the northern California Current (NCC) system, a strong upwelling zone, using time series of zooplankton sampled from a nearshore station (9 km offshore, water depth 62 m) and a shelf-slope station (46 km offshore, water depth 297 m). Long-term...
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...
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...
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...
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 20-year US GLOBEC (Global Ocean Ecosystem Dynamics) program examined zooplankton populations and their predators in four coastal marine ecosystems. Program scientists learned that environmental controls on zooplankton vital rates, especially the timing and magnitude of reproduction, growth, life-cycle progression, and mortality, determine species population dynamics, seasonal and spatial distributions,...
The goal of the Pacific Ocean Boundary Ecosystem and Climate Study
(POBEX) was to diagnose the large-scale climate controls on regional transport
dynamics and lower trophic marine ecosystem variability in Pacific Ocean boundary
systems. An international team of collaborators shared observational and eddy-resolving
modeling data sets collected in the Northeast...
Coastal upwelling in the northern California Current
varies seasonally, with downwelling in winter and upwelling
in summer, resulting in pronounced variability in
hydrography, nutrients, phytoplankton biomass, and species
composition. Winter was characterized by moderate concentrations
of nitrate and silicate (averages of 10 and 18 μM,
respectively) and low concentrations of...
This study addresses the occurrence, severity, and extent of hypoxia over the continental shelf of the northern
California Current (40–48.5°N latitude) from 1998 to 2012. Clear seasonal trends exist in the timing and duration
of hypoxia. The highest bottom-water dissolved oxygen concentrations occurred from November to March, and
levels below...
Larval supply determines year-class strength of fisheries and complex ecological
interactions among adults of benthic marine species. In upwelling regions, a latitudinal cline in
the intensity and persistence of upwelling is thought to affect larval advection and recruitment,
thereby regulating the intensity of interactions in adult populations and communities. We...
Research on regulatory mechanisms in biological populations often focuses on environmental covariates. An integrated
approach that combines environmental indices with organismal-level information can provide additional insight on
regulatory mechanisms. Survival of spring/summer Snake River Chinook salmon (Oncorhynchus tshawytscha) is consistently
low whereas some adjacent populations with similar life histories experience...
Significant seabird mortality on the Oregon (OR) and Washington (WA) coast in 2009 has been attributed to a massive bloom of the dinoflagellate Akashiwo sanguinea (K. Hirasaka) G. Hansen & Ø. Moestrup. Initial, albeit limited, observations suggested this bloom began in WA and reached OR waters through southward transport. Here,...