Axenic cultures of 25 species of unicellular marine algae were tested for their ability to utilize nine common amino acids, supplied at high concentrations in batch culture, as a nitrogen source; most species were able to use several amino acids, although growth was often slower than on nitrate nitrogen. The...
Seasonal and diel changes in nutrient concentrations and nitrogen assimilation rates were used to assess the effects of NH4+ on NO3- assimilation. Surface-water NO3- concentrations ranged from 6 to 17 μM while NH4+ concentrations ranged from 0 to 0.4 μM. Total N assimilation ranged from 84 to 732 nM d–1...
Using 15N-labeled NH4+, we assessed the time-course of NH4+ uptake, the parameters of saturation kinetics, and the rates of incorporation of NH4+ into trichloroacetic acid-insoluble material by Chesapeake Bay phytoplankton. The amount of NH4+ taken up by the phytoplankton increased linearly with time for 2 h for all samples growing...
Ammonium uptake and regeneration rates were measured in time course experiments with 15N as a tracer. Both ammonium uptake and regeneration rates measured over 12 to 18 h remained essentially constant. However, as the length of the incubations increased the amount of usable data decreased dramatically due to substrate depletion...
The stable isotopic signature of dissolved inorganic carbon (δ¹³CDIC) in the northeast Pacific Ocean is lower in near-surface waters by 1.1‰ relative to values predicted from global oceanic trends of δ¹³CDIC versus nutrients. A combination of anthropogenic carbon uptake from the atmosphere and thermodynamic, air-sea gas exchange processes in different...
The relationship between nitrogen (N) availability and the growth of macroalgae in a seasonal upwelling region (Yaquina Head, Oregon, USA) was investigated. Water column nutrient concentrations were relatively high and stable during the winter, decreased in early spring, and were highly variable in the summer and early fall. Periods of...
Insight into the dependence of benthic communities on biological and physical processes in nearshore pelagic environments, long considered a ``black box,'' has eluded ecologists. In rocky intertidal communities at Oregon coastal sites 80 km apart, differences in abundance of sessile invertebrates, herbivores, carnivores, and macrophytes in the low zone were...
The purpose of this study was to test the hypothesis that NH4+ uptake by heterotrophic bacteria in the subarctic Pacific is C limited. Addition of glucose (0.5–1.0 μM) stimulated NH4+ uptake in unfractionated water but had no effect on bacterial abundance. Glucose stimulation of NH4+ uptake was even greater in...
Chlorophyll a concentrations were measured as a function of depth from 28 to 48°N along 152°W in March 1991 with Whatman GF/F and 0.2‐µm Nuclepore filters. Surface Chl a concentrations measured with 0.2‐µm Nuclepore filters were up to fourfold higher than those measured with Whatman GF/F filters. The largest difference...
Observed changes in the nutrient levels in the halocline of the California Current during 2002 indicated a natural eutrophication that was accompanied by increased chlorophyll and oxygen in surface water. Decreased oxygen in the lower water column over the shelf indicated that much of the phytoplankton production was respired rather...
Analyzes subscription costs and impact factors for journals in which COAS faculty most frequently published from 1994-2003. Includes a spreadsheet with journal title, subscription cost, impact factor, publisher, information about whether the journal is published by a non-profit or commercial publisher, and cost per page.
Diel periodicity in NH4+ uptake and regeneration in the nutrient-rich environment of the oceanic subarctic Pacific was examined. Surface water was incubated in large shipboard microcosms that allowed repeated sampling of the planktonic community for NH4+ cycling rates, bacterial production rates, and population densities of the dominant autotrophs and heterotrophs....
It has been suggested that production in offshore waters of the subarctic Pacific is limited by availability of dissolved Fe. Although that is not yet adequately established, the functional consequences of the limitation (if it exists) can be characterized from the results of the Subarctic Pacific Ecosystem Research (SUPER) program....
The Coastal Ocean Advances in Shelf Transport (COAST) program conducted an
interdisciplinary study of coastal upwelling off central Oregon during summer 2001.
Two intensive field efforts during May–June and August 2001 were coordinated with
ocean circulation, ecosystem, and atmospheric modeling of the region. A primary
goal was to contrast the...
The relationship between iron and nitrate concentrations was examined off the coast of
Oregon during the upwelling season. Surface Fe and N (nitrate + nitrite) concentrations
measured underway by flow injection analysis ranged from <0.3 to 20 nmol L¯¹ and <0.1 to
30 mmol L¯¹, respectively. Total dissolvable Fe concentrations,...
Despite the importance of the spring phytoplankton bloom off Oregon as a food source for zooplankton, little is known about the sources of phytoplankton seed stock for the bloom or its timing. Experiments were conducted in the late winter to determine if the benthic boundary layer (BBL) could be a...
The uptake of methylammonium (MA) by Chesapeake Bay phytoplankton was measured in short term experiments by using the 14C radioisotope. This uptake was inversely related to ambient NH4+ concentrations, and the specificity for uptake of both substrates was demonstrated by competitive inhibition. At stations with low ambient NH4+, MA uptake...
PN-specific, absolute, and Chl a-specific nitrate uptake rates were measured during two upwelling seasons and one winter off Oregon. Although PN-specific and absolute uptake rates showed no dependence on nitrate concentration, Michaelis-Menten kinetics applied when the uptake rates were normalized to Chl a. Chl a-specific nitrate uptake rates were saturated...
The uptake rates of nitrate, ammonium, and urea were measured with a ¹⁵N technique during seven cruises in the marginal ice zone (MIZ) in the Barents Sea in 1984–1988. The results from all the cruises were pooled to obtain means for the prebloom, bloom, transition, and postbloom periods. New production—nitrate...
Uptake of nitrogenous nutrients by microplankton off the Washington and Oregon coasts was measured during the 1985 upwelling period. Nitrogen uptake rates in low-NO3- waters (<5 μM) were 0.020–0.258 μmol N liter-1 h-1 and were primarily supported by regenerated nitrogen (71% of total uptake). Nitrogen uptake rates in high-NO3- waters...
We examined high-resolution cross-shelf distributions of particulate organic carbon
(POC) and dissolved O₂ during the upwelling season off the Oregon coast. Oxygen
concentrations were supersaturated in surface waters, and hypoxic in near-bottom
waters, with greatly expanded hypoxic conditions late in the season. Simplified time-dependent
mass balances on cross-shelf integrated concentrations...
The particulate and dissolved organic carbon and nitrogen data included in this report are
a complete version of all data for GLOBEC cruises 1997-2004. The nutrient and
chlorophyll data that correspond to this data set can be found in “Nutrient and Extracted
Chlorophyll Data from the GLOBEC Long-Term Observation Program,...
The particulate and dissolved organic carbon and nitrogen data included in this report are a complete version of all data for GLOBEC cruises 1997-2004. The nutrient and chlorophyll data that correspond to this data set can be found in "Nutrient and Extracted Chlorophyll Data from the GLOBEC Long-Term Observation Program,...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 5 lines (off Newport, Heceta Head, Coos Bay, the Rogue River, OR. and Crescent
City, CA.), to make continuous...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 4 lines (off Newport, Heceta Head, Coos Bay, OR. and Crescent City, CA.), to
deploy drifters at selected locations...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along one line off Newport, OR, and to make continuous observations of currents using
ADCP and of surface-layer temperature, salinity...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net tow stations along 5 lines (off Newport, Heceta Head, Coos Bay, the Rogue River and Crescent City, OR, to deploy drifters at...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 5 lines (off Newport, Heceta Head, Coos Bay, the Rogue River, OR. and Crescent
City, CA., to make continuous...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 5 lines (off Newport, Heceta Head, Coos Bay, the Rogue River, OR. and Crescent
City, CA.), to make continuous...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net tow stations along the Newport Hydro line, to make continuous bio-acoustic observations between the 50-500m. isobath, and to make continuous observations of...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 5 lines (off Newport, Heceta Head, Coos Bay, the Rogue River, OR. and Crescent
City, CA.), to make continuous...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net tow stations along the Newport Hydro line, to make continuous bio-acoustic observations between the 50-500m. isobath, and to make continuous observations of...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 5 lines (off Newport, Heceta Head, Coos Bay, the Rogue River, OR. and Crescent
City, CA.), to make continuous...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in the NE Pacific. In particular, to make CTD/rosette and
net tow stations along the Newport Hydro line, to make continuous bio-acoustic observations
between the 50-500m. isobath, and to make continuous observations of currents...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along the Newport Hydro line, to make continuous bio-acoustic observations between
the 50-500m. isobath, and to make continuous observations of...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 5 lines (off Newport, Heceta Head, Coos Bay, the Rogue River, OR. and Crescent
City, CA.), to make continuous...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 5 lines (off Newport, Heceta Head, Coos Bay, the Rogue River, OR. and Crescent
City, CA.), to make continuous...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along the Newport Hydro line, and to make continuous observations of currents using
ADCP and of surface-layer temperature, salinity and...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along the Newport Hydro line, and to make continuous observations of currents using
ADCP and of surface-layer temperature, salinity and...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 5 lines (off Newport, Heceta Head, Coos Bay, the Rogue River, OR. and Crescent
City, CA.), to deploy drifters...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 5 lines (off Newport, Heceta Head, Coos Bay, OR. and Crescent City, CA.), to
deploy drifters at selected locations...
PURPOSE (W0408D): To determine physical, plankton and nutrient/chemical conditions over the
continental margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/
rosette and net tow stations along 3 lines (off Newport, Strawberry Hill and Heceta Head, OR.), and
to make continuous observations of currents...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along 4 lines (off Newport, Coos Bay, Crescent City and Eureka), to make additional
stations along a fifth line (off...
PURPOSE: To determine physical, plankton and nutrient/chemical conditions over the continental
margin for climate change studies in NE Pacific. In particular, to make CTD and CTD/rosette and net
tow stations along one lines off Newport, OR, and to make continuous observations of currents using ADCP and of surface-layer temperature, salinity...
Few studies have examined the partitioning of organic matter in upwelling systems, despite the fact that these systems play a key role in carbon and nitrogen budgets in the ocean. We examined the production and partitioning of phytoplankton-derived organic matter in deck incubations off Oregon during the upwelling season. During...
The data set presented here includes the discrete depth profile data and time series data
from the vertical profiling cruises carried out as a portion of the “Coastal Ocean Advances in Shelf Transport” (COAST) project. The primary purpose for collection of this data set was to calibrate the optical parameters...
Dissolved organic matter (DOM) production was examined in axenic batch cultures of five coastal diatom species. For Chaetoceros decipiens, dissolved organic carbon (DOC) accumulated beginning in late exponential growth as a result of increased cell density. For Cylindrotheca closterium, DOC actually decreased in late exponential growth and reached zero by...