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ScholarsArchive at Oregon State University
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Small, aloricate ciliates with equivalent spherical cell diameters ~20 km (biovolume <4,000 pm3) compose, on average, 4-57%
of the total biomass of heterotrophic (apochlorotic) nanoplankton in diverse marine systems. Biomass production of...
1986 (iso8601)
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We compared estimates of bacterial abundance and of average bacterial cell size based on direct counts of bacterioplankton cells stained with acridine orange (AO) or 4’-6-diamidino-2-phenylidole (DAPI). Estimates of numbers mll–1 of bacteria...
1993 (iso8601)
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Horizontal transects of fluorescence measurements have been used extensively to investigate phytoplankton patchiness. Variance spectra have been calculated from these data, thus quantifying spatial heterogeneity as a function of length scale....
1980 (iso8601)
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Chlorophyll-temperature profiles were measured across Lake Tahoe about every 10 days from April through July 1980. Analysis of the 123 profiles and associated productivity and nutrient data identified three important processes in the formation and...
1984 (iso8601)
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There is considerable interest in the biogeochemical cycling of cadmium (Cd) and phosphate (PO4) in surface waters, driven in part by the ongoing development of a paleonutrient proxy that utilizes Cd preserved in fossil planktonic foraminifera to...
2003 (iso8601)
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Iron is recognized as a key element regulating primary production in large regions of the ocean, but nothing is known of its direct effect on higher trophic levels. Two species of heterotrophic protozoa were thus fed iron-rich and iron-poor...
1997 (iso8601)
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A Russian–American fieldwork effort on Lake Baikal, its tributaries, and surrounding hot springs was undertaken in June–July 1991. Here we report on aspects of major ion (Ca2+, Mg2+, Na+, K+, Alk, Cl–, SO42–) and several minor and trace element...
1997 (iso8601)
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A comprehensive, joint Soviet-American study of the chemistry of Lake Baikal, the world’s deepest (1,632 m) lake, was carried out in July 1988. In this paper, we report the major, minor, and preliminary trace element concentrations for three...
1991-05 (iso8601)
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Algal chlorophyll and carotenoid distributions were measured periodically in the euphotic zone of Sta. ALOHA (22º45′N, 158º00′W) between February 1989 and October 1991 to document the variability in phytoplankton abundance and composition. The...
1993 (iso8601)
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Based on a long-term set of observations and measurements at a station in the subtropical North Pacific Ocean, it now appears that contemporaneous rates of primary production in low-nutrient open ocean regions and perhaps in the ocean as a whole...
1998 (iso8601)
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The euphotic zone below the deep chlorophyll maximum layer (DCML) at Station ALOHA (a long-term oligotrophic habitat assessment; 22º45′N, 158º00′W) transects the nearly permanently stratified upper thermocline. Hence, seasonal changes in solar...
2004 (iso8601)
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We examined variability in the natural fluorescence yield of a neritic diatom, Thalassiosira weissflogii, in continuous cultures. In this species, kinetics in natural fluorescence yield over time scales less than a photoperiod were characterized...
2005 (iso8601)
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Storage lipids of fifth copepodites (C5) of Culanus finmarchicus from Georges Bank and the Gulf of Maine were quantified from video images and by Iatroscan (thin-layer chromatography with flame-ionization detection, FID). Oil withdrawn from the...
1998 (iso8601)
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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...
1991 (iso8601)
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Rates of molting of a specific copepodite stage can be determined by sorting the stage from a new collection, waiting, then counting the number that have molted to the next stage in the interval. In principle, stage duration can be determined as...
1984 (iso8601)
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Several species of the copepod genus Acartia are shown from existing data to complete each molt-to-molt phase of the life cycle in a constant time period. This molting pattern is termed isochronal development. Increase in mass at each stage is a...
1977-03 (iso8601)
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Stratified bongo net samples taken at depths between 0 and 500 m at Ocean Station “P” in the subarctic Pacific in early July 1971 have been analyzed to determine the vertical structure of the zooplankton community. Distributions for 99 categories...
1975-09 (iso8601)
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An attempt has been made to interbreed populations of Acartia clausi from Woods Hole, Massachusetts, and Yaquina Bay, Oregon. Individuals from these populations are morphologically similar, but differ somewhat in size. Cultures from both sources...
1974-05 (iso8601)
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The spatial distribution of plankton is highly aggregated, so one might expect that a vertically migrating animal enters a biotic environment that is markedly different each evening and that the changes in environment between daylight periods...
1970 (iso8601)
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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...
1990 (iso8601)
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The relative contribution of various inorganic and organic forms of nitrogen to the nitrogen requirements of picoplankton was examined with 15N tracers. Size fractionation was used to measure uptake by <1-μM size microorganisms, and inhibitors of...
1986 (iso8601)
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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...
1989 (iso8601)
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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+...
1982 (iso8601)
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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...
1982 (iso8601)
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Uptake of [14C]glycine by various size fractions of natural plankton communities was measured to determine if phytoplankton can compete effectively with other members of the plankton community for the free amino acids in seawater. The simultaneous...
1977-09 (iso8601)
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