Drifters released offshore of Oregon during predominantly downwelling favorable alongshore winds during three different deployments (October 1994, January 1998, and September 1998) display similar behavior: after being advected around in the offshore eddy field, they move onshore to a particular isobath and are advected poleward alongshore, without coming ashore. Numerical...
During fall/winter off the Oregon coast, oceanographic surveys are relatively scarce because of rough
weather conditions. This challenge has been overcome by the use of autonomous underwater gliders deployed
along the Newport hydrographic line (NH-Line) nearly continuously since 2006. The discharge from the
coastal rivers between northern California and the...
Knowledge of nutrient pathways and their resulting ecological interactions can alleviate numerous environmental problems associated with nutrient increases in both natural and managed systems. Although not unique, coastal systems are particularly prone to complex ecological interactions resulting from nutrient inputs from both the land and sea. Nutrient inputs to coastal...
The filamentous fungus Neurospora crassa responds to light in complex ways. To thoroughly study the transcriptional response of this organism to light, RNA-seq was used to analyze capped and polyadenylated mRNA prepared from mycelium grown for 24 hr in the dark and then exposed to light for 0 (control) 15,...
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...
In late spring of 2010, the northern California Current (NCC) experienced a transition from El Niño to La Niña conditions resulting in anomalous distributions and concentrations within the ichthyoplankton community. We analyzed larval fish data collected during the four months before and after this transition and compared them to data...
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...
From mid-May to August 2011, extreme runoff in the Columbia River ranged from 14,000 to over 17,000 m³/s, more than two standard deviations above the mean for this period. The extreme runoff was the direct result of both melting of anomalously high snowpack and rainfall associated with the 2010–2011 La Niña....
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...
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...
Freshwater discharge from large rivers into the coastal ocean creates tidally-driven frontal systems
known to enhance mixing, primary production, and secondary production. Many authors suggest that
tidal plume fronts increase energy flow to fish-eating predators by attracting planktivorous fishes to feed
on plankton aggregated by the fronts. However, few studies...
Three stations, at similar to ~80 m water depth on the Oregon shelf between 44.7 degrees N and 43.9 N, were studied under hypoxic conditions in late spring and summer of 2009 to determine benthic oxygen consumption rates. Oxygen fluxes were derived from eddy correlation (EC) measurements made from an...
Concentrations of domoic acid (DA) above the regulatory limit in Washington coast razor clams are usually higher on northern beaches from summer to fall. Recent field studies have confirmed that the primary source of toxic Pseudo-nitzschia (PN) cells in those seasons is a semi-retentive topographically trapped seasonal eddy located offshore...
Phytoplankton species were enumerated from 72 samples collected biweekly during the upwelling season (May to August) of 2001−2010 to test for effects of interannual variations in upwelling and decadal basin-scale variability on phytoplankton species composition and community structure. Cluster analysis of phytoplankton community structure identified 7 groups; 1 group was...
Riverine plumes in nearshore coastal waters are areas of enhanced production and accumulation of prey and may increase availability of food during a critical period of juvenile salmon survival and hence serve as a nursery area for these juveniles. Physical and biological sampling was conducted along a cross-shelf transect through...
The tidally varying circulation, stratification, and salt flux mechanisms are
investigated in a shallow salt wedge estuary where fluvial and tidal velocities are large and
the steady baroclinic circulation is comparatively weak. The study integrates field
observations and numerical simulations of the Merrimack River estuary. At moderate to
high discharge...
The intermittent upwelling hypothesis (IUH) predicts that the strength of
ecological subsidies, organismal growth responses, and species interactions will vary
unimodally along a gradient of upwelling from persistent downwelling to persistent upwelling,
with maximal levels at an intermediate or ‘‘intermittent’’ state of upwelling. To test this model,
we employed the...
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...
Physical exchange between estuarine and continental shelf waters impacts flushing dynamics of the estuary and determines rates of ocean inputs of nutrients and plankton. To investigate the occurrence and propagation of shelf water intrusions into the Narragansett Bay estuary, we collected velocity data near the estuarine–shelf interface during three summer...
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...
In marine ecosystems, rising atmospheric CO2 and climate change are associated with concurrent shifts in temperature, circulation, stratification, nutrient input, oxygen content, and ocean acidification, with potentially wideranging biological effects. Population-level shifts are occurring because of physiological intolerance to new environments, altered dispersal patterns, and changes in species interactions. Together...
The zooplankton of the northern California Current are typically characterized by an abundance of lipid-rich copepods that support rapid growth and survival of ecologically, commercially, and recreationally valued fish, birds, and mammals. Disruption of this food chain and reduced ecosystem productivity are often associated with climatic variability such as El...
The status of the double-crested cormorant (Phalacrocorax auritus) in western North America was last evaluated during 1987–2003. In the interim, concern has grown over the potential impact of predation by double-crested cormorants on juvenile salmonids (Oncorhynchus spp.), particularly in the Columbia Basin and along the Pacific coast where some salmonids...
Non-breeding sooty shearwaters are the most abundant seabird in the California Current Large Marine Ecosystem (CCLME) during boreal spring and summer months. This, combined with relatively great energy demands, reliance on patchy, shoaling prey (krill, squid, and forage fishes), and unconstrained mobility free from central-place-foraging demands-make shearwaters useful indicators of...
We investigated the export of particulate organic matter (POM) to the ocean by two contrasting small, mountainous rivers, the Umpqua and Eel Rivers, by collecting suspended sediment samples over a range of discharges and analyzing them for a variety of constituents, including organic carbon, nitrogen, biomarkers with distinct biochemical sources,...
The community of trophically transmitted marine parasites of juvenile coho (Oncorhynchus kisutch) and Chinook
(Oncorhynchus tshawytscha) salmon across 8 years (2002–2009) was related to indices of physical and biological ocean conditions
and adult returns. When the biomass of lipid-poor, southern origin copepods in the coastal ocean was high during juvenile...
Along the Pacific coast of North America, from Alaska to Mexico, harmful algal blooms (HABs) have caused losses to natural resources and coastal economies, and have resulted in human sicknesses and deaths for decades. Recent reports indicate a possible increase in their prevalence and impacts of these events on living...
We compiled existing data and information to characterize the condition and trends in high priority natural resources in Ebey’s Landing National Historical Reserve (EBLA, or "the Reserve"). We identified 29 indicators to evaluate seven major resource concerns. For each indicator we attempted to define reference conditions to which we could...
Published July 1987. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog