In an effort to elucidate the mechanism responsible for large-scale
zooplankton variability in the California Current, zooplankton biomass and
hydrographic data from the California Cooperative Fisheries Investigation
data set and wind data from Fleet Numerical Oceanography Center model
analyses have been used to construct a box model biomass budget. The...
The Northern California Current (NCC) ecosystem exhibits extreme seasonal, interannual and interdecadal shifts in the abiotic environment and shifts in primary and higher production. This variability is also apparent in the spatial structure of the ecosystem with nearshore-shelf waters (<150 m isobath) being highly productive and having a different community...
In eastern boundary current upwelling ecosystems, mesoscale circulation features such as eddies and upwelling filaments play a prominent role in the transfer of water and the associated plankton from the productive nearshore to the oligotrophic deep sea. The relationship between mesoscale circulation, zooplankton distributions, and the across-shelf transport of coastal...
Small pelagic fish represent a critical trophic link between plankton and large predators in marine upwelling ecosystems such as the California Current System. Populations of these fish are highly variable over time and are characterized by extreme fluctuations in abundance, which have significant ecosystem impacts. The causes driving
this instability...
Recruitment of larvae from the plankton is an important determinant of
community structure in marine systems. In populations of many marine species,
recruitment determines the basic demographic parameters of immigration, emigration,
and reproduction. Moreover, the effect of recruitment as an "ecological subsidy" can
determine the strength of interactions among species...
Three deep-sea subsurface moorings, each equipped with five current meters at depths from 150m below the surface to 200m above the bottom, were deployed off Northern California from September 1984 to July 1985 as part of the OPTOMA program. The triad of moorings, centered near 38.5°N, 125°W, had mutual separations...
Temperature, salinity, density and turbulent dissipation profiles measured using the Rapid Sampling Vertical Profiler during the Coastal Transition Zone Experiment, July 1988.
CTD observations were made in the Code region near Pt Arena on the northern California coast at 39°N, off Purisima Pt. at 34°45'N and off Crescent City at 41°54'N, during 25 April - 7 May 1981. The observations in the Code region included four repeated sections along the Central Line,...
Surface drifters were depldyed and tracked over the continental shelf and upper continental slope off central California between Point Conception and Point Sur. The drifters were deployed and tracked from aircraft by Aero-Marine Surveys, Inc. under subcontract to Raytheon Service Company as part of the Central California Coastal Circulation Study...
During some of the CODE mooring deployment and recovery cruises, CTD
observations were made on an ancillary basis. In conjunction with the recovery
of the CODE-2 array, CTD observations were made during 3-5 August
(CODE-2 Leg 10) and 19 August (CODE-2 Leg 13). The CTD observations were
made alongside current...
CTD observations were made in the CODE region between Pt. Arena (39°N) and Pt. Reyes (38°N) during 17 March - 4 April 1982. The observations were along three sections: Code Central, Code - 2 Central, and Irish Gulch Lines; and alongside seven current meter moorings.
Maximum sampling depth was 500...
CTD observations were made in the CODE region between Pt. Arena (39°N) and Pt. Reyes (38°N) during 28 February - 1 March 1982. The observations were made along three sections: the Arena Line, the North Line and the Code Central Line. An additional single CTD cast was made off Eureka...
CTD observations were made in the Code region near Pt. Arena on the northern California coast at 39°N, off Crescent City at 41°54 1 N, off Half Moon Bay at 37°25'N and off Pt. Purisima at 34°45'N during 2-13 July 1981. The observations in the Code region included three repeated...
CTD observations were made in the Code region near Pt. Arena on
the northern California coast at 39°N, off Five Mile Point at 43°13'N,
off Crescent City at 41°54'N, and off Half Moon Bay at 370 25'N,
during 17-29 May 1981. The observations in the Code region included
six repeated...
The area near Point Arguello has long been recognized as a location of strong
upwelling. A tongue of biologically active waters was observed in the earliest studies of
this region (Sverdrup and Allen, 1939). More recently, satellite estimates of chlorophyll by
the Coastal Zone Color Scanner (CZCS) on Nimbus-7 have...
CTD observations were made over the continental shelf and upper continental slope from the coast to approximately 60 km off central California between latitudes 34°N and 37.5°N. The measurements were made by Raytheon Service Company as part of the Central California Coastal Circulation Study sponsored by the Minerals Management Service....
Wecoma cruise W8807A was conducted in late July and early August 1988 as part of the Coastal Transition Zone project. CTD observations were made over a standard grid in the coastal transition zone off northern California between 37°N and 39.5°N that was occupied repeatedly during June, July and August; this...
Wecoma cruise W8706A was conducted in June 1987 as part of the pilot study for the Coastal Transition Zone project. CTD observations were made in the coastal transition zone off northern California between 37.5°N and 41.5°N and along 43°13'N off Coos Bay, Oregon. Altogether 133 stations were completed successfully. They...
Wecoma cruise W8702B was conducted in February 1987 as part of the pilot study for the Coastal Transition Zone project. CTD observations were made in the coastal transition zone off northern California between 37.5°N and 4l.5°N. Stations were planned along three alongshore transects, at distances of 60, 90 and 150...
CTD observations were made over the continental shelf and upper
continental slope from the coast to approximately 60 km off central California
between latitudes 34°N and 37.5°N. The measurements were made by Raytheon
Service Company as part of the Central California Coastal Circulation Study
sponsored by the Minerals Management Service....
CTD observations were made over the continental shelf and upper
continental slope from the coast to approximately 60 km off central California
between latitudes 34°N and 37.5°N. The measurements were made by Raytheon
Service Company as part of the Central California Coastal Circulation Study
sponsored by the Minerals Management Service....
CTD observations were made over the continental shelf and upper
continental slope from the coast to approximately 60 km off central California
between latitudes 34°N and 37.5°N. The measurements were made by Raytheon
Service Company as part of the Central California Coastal Circulation Study
sponsored by the Minerals Management Service....
The high productivity of Eastern Boundary Upwelling Ecosystems (EBUE), some of the most productive ecosystems in the globe, is attributed to the nutrient rich waters brought up through upwelling. Climate change scenarios for coastal upwelling systems, predict an intensification of coastal upwelling winds. Associated with intensification in upwelling are biogeochemical...
As part of the SuperCODE project, three hydrographic cruises were conducted
off Oregon and California in July 1983, and January to February 1984,
and April 1984. CTD observations were made near Coos Bay at 43°13'N during 12
July 1983 and 31 January 1984, and off Newport at 44°39'N on 11-12...
As part of the SuperCODE and CODE projects, two hydrographic cruises were conducted off Oregon and California in January and April 1984. CTD sections across the continental shelf and slope were made near Coos Bay at 43°13'N, off Crescent City at 41°54%, off Eureka at 40°51%, along the Arena and...
CTD observations were made along sections near Coos Bay at 43° 13'N, off Crescent City at 41° 54'N, off Eureka at 40° 51 'N, off of Half Moon Bay at 37°2q'N, off of Pt. Purisima at 34° 45'N, and along the Code Central and Pt. Arena lines near 39°N during...
CTD observations were made in the Code region near Pt. Arena on the
northern California coast at 39°N, off Coos Bay at 43°12'N, off Crescent
City at 41°54'N, of Eureka at 40°51'N, off Half Moon Bay at 37°25'N, off
Pt. Purisima at 34°45'N and in the Santa Barbara Channel during...
Current meter moorings were recovered and deployed off of Coos Bay at 43°13'N, off of Crescent City at 41°54'N, off of Half Moon Bay at 37°25'N and off of Pt. Purisima at 34°45'N during 28-29 January 1982. CTD observations were made off of Coos Bay at 43°13 1 N, off...
CTD observations were made in the CODE region near Pt. Arena on the northern California coast at 39°N, off Coos Bay, Oregon at 43°13'N, off Crescent City at 41°541N, and off Half Moon Bay at 37°25'N. The observations in the CODE region included two repeated sections along the Central Line,...
This dissertation focuses on the importance of pelagic subsidies in the Northeast Pacific to rocky shore community regulation. My results document the patterns of pelagic subsidy supply, determine if those subsidies are correlated with community structure, and examine if community regulation differs between areas of high- and low-subsidies. Understanding how...
CTD observations were made along the CODE Central Line, extending offshore toward 225°T from the California coast at 38°40'N, during 12-14 April, 1981. The complete section with nine stations was occupied twice; the offshore portion was occupied three times. The maximum sampling depth was 1000 m. This report includes a...
Reintroduction programs are increasingly being used to save animals from extinction and aid in their recovery. The California Condor (Gymnogyps californianus), one of the most endangered birds in the world, is a remarkable example of how reintroduction programs can help rapidly increase a species' population numbers and range following a...
The effects of wind forcing on coastal ocean circulation are studied using a
numerical modeling approach. The first region of interest is on the North Carolina
shelf, where the Coastal Ocean Processes (CoOP) Inner Shelf Study (ISS) took place
during August - November 1994. ISS observations are used to initialize,...
The Optical Dynamics Experiment (ODEX) cruise of Oct and Nov 1982 occupied 1984 stations along a transect from the California coast at 35°N to a study area covering the subtropical front near 32°N, 142°W. This report presents data collected with spectral—radiometer instrument package and particle size distributions of discrete water...
A large-scale west coast shelf experiment called SuperCODE
was conducted off Oregon and California between February 1981
and April 1984. Current and temperature measurements were made
from subsurface arrays off Coos Bay (43°N), Crescent City
(42°N), Eureka (41°N), Half Moon Bay (37.5°N) and Purisima
Point (34.70), between February 1981 and...
As part of the U. S. GLOBEC NorthEast Pacific Program we made repeated seasonal hydrographic surveys in the northern California Current system (Figure 1) between July 1997 and September 2003. These surveys included early spring sampling along a pair of hydrographic sections, one north (at 44.6ºN) and one south (at...
Wind-driven coastal upwelling brings subsurface water onto the central-Oregon shelf after the spring transition each year. This cold and salty source water is oxygen-poor, yet above the hypoxic threshold, dissolved oxygen < 1.4 ml l⁻¹. Once on the shelf, dissolved oxygen (DO) concentrations of upwelled near-bottom waters are modified by...
CTD observations of temperature and salinity were made off Oregon and California between 34° N and 44° N from the R/V Wecoma, 5 Feb. - 17 Feb. 1981. The stations were from 2-360 km off shore, in water depths ranging from 30 to 4,300 meters. The maximum sampling depth at...
Euphausia pacifica, the North Pacific krill, is a key grazer in the California Current System and an important prey item for consumers such as salmon, seabirds, and whales. As a crucial link between phytoplankton and higher trophic levels, it is essential to understand both the behavior and bioenergetics of this...
This study was designed to identify and characterize areas of concentrated use and diving behavior of blue whales (Balaenoptera musculus) off the California coast. During the summer of 2004, thirteen blue whales were tagged with implantable Telonics ST-15 Argos satellite-monitored radio tags and five were tagged with Telonics ST-21 Argos...
Variable ocean conditions can greatly impact lower trophic level prey assemblages in marine ecosystems, with effects propagating up to higher trophic levels. Our goal was to better understand how varying ocean conditions influence diets and niche overlap among a suite of low- to mid trophic level predators. We studied the...
Bathers exposed to microbiological contamination in coastal waters have an excess risk of gastrointestinal and respiratory illness. The disease burden associated with this risk may be considerable in Southern California, where 50 million annual beach visitors recreate in coastal waters that receive billions of gallons of polluted discharges from nearby...
Within systems characterized by substantial spatial and temporal variability, abundances of organisms tend to be higher in localized areas. Within the northern California Current system, the identification of such marine, biological hotspots would be of great importance to resource managers, conservationists, and research planners, and is consequently a growing area...
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Chapter 2: Community Structure of Near-surface Zooplankton in the
Northern California Current
Ocean Acidification (OA) has emerged as a major threat to marine ecosystems, particularly regarding calcifying organisms. A growing body of literature describing laboratory investigations into pH stress indicates broadly deleterious effects for calcifiers, but responses vary greatly across taxa and can be influenced by variations in other environmental characteristics. Scaling...
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...
This dissertation examines tsunami and hurricane wave loads on bridge superstructures. Tsunamis have caused significant damage to coastal communities in recent years. For example, the 2011 Great East Japan Earthquake and resulting Tohoku Tsunami destroyed infrastructure along the east coast of Japan including bridge superstructures. Recent hurricanes have also caused...
The movement of Chinook salmon through space and time, across political boundaries, and through fisheries, creates one of the most complex marine resource management problems in the world. Information garnered from the recovery of coded-wire tags (CWTs) has been used since the 1970s to direct management decisions. Growing concern surrounding...
Ocean acidification (OA) has emerged as an important focus of research and policy in this decade. Ocean acidification specifically refers to changes in the inorganic carbon system in the ocean resulting from its absorption of human-released CO₂ from the atmosphere. Anthropogenic atmospheric CO₂ levels are rapidly increasing; much of this...
Recent research conducted throughout the Northern California Current (NCC) on the ecology of Pacific salmon (Oncorhynchus spp.) indicates that variable ocean conditions affect the community composition of zooplankton in the nearshore environment which, in turn, can affect the quality of prey for fish, sea birds and mammals. Interannual variability in...