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Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for approximately 20% of global carbon fixation. We report the 34 million-base pair draft nuclear genome of the marine diatom Thalassiosira pseudonana and its 129 thousand-base pair plastid and 44 thousand-base pair mitochondrial genomes. Sequence and(More)
The substantial inventory of nitrate (NO 3) in San Francisco Bay (SFB) is unavailable to the resident phytoplankton most of the year due to the presence of ammonium (NH 4) at inhibitory concentrations that prevents NO 3 uptake. Low annual primary productivity in this turbid estuary is generally attributed to the poor irradiance conditions. However, this may(More)
San Francisco Bay has been considered an HNLC or HNLG (high nutrient low chlorophyll or low growth) region with nonlimiting concentrations of inorganic nutrients yet low standing stocks of phytoplankton. Most of the studies leading to this conclusion come from the South Bay and little is known about nutrient processes and phytoplankton productivity in the(More)
Primary production in the Northern San Francisco Estuary (SFE) has been declining despite heavy loading of anthropogenic nutrients. The inorganic nitrogen (N) loading comes primarily from municipal wastewater treatment plant (WTP) discharge as ammonium (NH(4)). This study investigated the consequences for river and estuarine phytoplankton of the daily(More)
The use of 15N to measure the flux of nitrogen compounds has become increasingly popular as the techniques and instrumentation for stable isotope analysis have become more widely available. Questions concerning equations for calculating uptake, effect of isotope dilution (in the case of ammonium), duration of incubation, and relationship between(More)
A theoretical basis for analyzing new production of upwelling centers under various conditions and for comparing the relative performance of different upwelling centers has been developed using the concept of shift-up or acceleration of N03-uptake. NO,-concentration at the beginning of an upwelling cycle determines the rate of acceleration, the maximal(More)
PCR primers were designed and used to amplify glnA, the gene that encodes glutamine synthetase, from pure cultures of cyanobacteria and four samples from different marine environments. The glnA phylogeny was similar to that of the 16S rRNA gene, indicating that glnA gene sequences can be used to identify cyanobacteria expressing the glnA gene. Diverse(More)
Size and frequency of division were determined for zooxanthellae from nine scleractinian coral species collected in February, 1983 at Discovery Bay, Jamaica, from four depths over a 51 m bathymetric range. Mean diameters of zooxanthellae ranged from 6.4 to 12.6 μm. Small zooxanthellae were found in Madracis mirabilis, Eusmilia fastigiata and Dendrogyra(More)
Gram-negative rod-shaped bacteria (1.5–2μm long and 0.5μm wide) have been found associated with green hydra. They are always present on the hydra surface delineating the ectodermal cells, on animals in culture, and also on those sampled from a natural habitat. The bacteria could be removed by a 30-min treatment with antibiotics (50μ/ml polymyxin B and(More)
During the OPUS (Organization of Persistent Upwelling Structures) study of the upwelling center at Point Conception, California, large (380 liter) plastic shipboard enclosures (barrels) were tested as experimental tools to study phytoplankton processes in isolation from variability in circulation and grazing. Barrels were filled with water from the(More)