Learn More
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)
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 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)
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)
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)
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)
a r t i c l e i n f o Diatom blooms Suisun Bay Food webs Bacterial production Sewage effluent Rare spring blooms, N20 μg l −1 chlorophyll a, were observed in the San Francisco Bay Delta during the drought year of 2014 in both the upper Sacramento River and in Suisun Bay. The upper Sacramento River bloom was dominated by chlorophytes, but biomass and(More)
Keywords: San Francisco Estuary primary production phytoplankton carbon ammonium nitrate a b s t r a c t We describe the results of a series of 96-h enclosure experiments conducted using water from stations in the northern San Francisco Estuary (SFE) along a gradient in ammonium (NH 4) and nitrate (NO 3) concentrations. Using dual-labeled 13 C/ 15 N(More)
Anthropogenic activities are altering total nutrient loads to many estuaries and freshwaters, resulting in high loads not only of total nitrogen (N), but in some cases, of chemically reduced forms, notably NH 1 4. Long thought to be the preferred form of N for phytoplankton uptake, NH 1 4 may actually suppress overall growth when concentrations are(More)