Interannual variability in dissolved inorganic nutrients in Northern San Francisco Bay Estuary

Peterson, David H.; Smith, Richard E.; Hager, Stephen W.; Harmon, Dana D.; Herndon, Raynol E.; Schemel, Laurence E.

doi:10.1007/978-94-009-5528-8_3

Cited by 43 publications

(32 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…comm.). Diatom dominance in the experimental enclosures is consistent with previous field studies in the northern SFE that have shown diatom dominance during phytoplankton blooms (Dugdale et al, submitted;Cloern, 1979;Cloern and Dufford, 2005;Lidström, 2009;Dugdale et al, submitted) and as an important food source within the pelagic foodweb of the SFE (Peterson et al, 1985).…”

Section: Discussionsupporting

confidence: 90%

The effect of inorganic nitrogen speciation on primary production in the San Francisco Estuary

Parker

Hogue

Wilkerson

et al. 2012

Estuarine, Coastal and Shelf Science

View full text Add to dashboard Cite

Keywords:San Francisco Estuary primary production phytoplankton carbon ammonium nitrate a b s t r a c tWe 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 tracers, we followed the timing and sequence of primary (carbon, C) production and phytoplankton nitrogen (N) use during experimental phytoplankton blooms. Our results show that diatoms consistently drive the phytoplankton blooms in the enclosures. By tracing both C and N uptake we provide clear evidence that high rates of C uptake are linked to phytoplankton NO 3 , and not NH 4 , use. Results from kinetics experiments demonstrated higher specific uptake rates (V MAx ) for NO 3 compared to NH 4 in the SFE. Finally, dissolved inorganic carbon and nutrient drawdown ratios in the enclosures from the chronically high NH 4 regions of the SFE were substantially lower than predicted from the Redfield ratio, suggesting suppressed C uptake, in relation to other elemental uptake. Our conceptual model of the DIN interactions that lead to higher primary production and phytoplankton blooms in the SFE suggests that higher rates of primary production that accompany phytoplankton NO 3 uptake are sufficient to outpace phytoplankton losses, leading to blooms, compared to the lower rates associated with NH 4 uptake (only 20% of that based upon NO 3 ). Historical changes in wastewater practices have increased the proportion of NH 4 to the DIN pool in the SFE leading to reduced access to NO 3 by phytoplankton. This may help to explain some of the reduced primary production and phytoplankton biomass observed there since the 1970s.

show abstract

Section: Discussionsupporting

confidence: 90%

The effect of inorganic nitrogen speciation on primary production in the San Francisco Estuary

Parker

Hogue

Wilkerson

et al. 2012

Estuarine, Coastal and Shelf Science

View full text Add to dashboard Cite

show abstract

“…6). This observation is consistent with Peterson et al (1985) who observed that dissolved N, P, and Si are distributed along the estuary as conservative constituents during periods of low phytoplankton productivity and nutrient uptake. To explore further the hypothesis that phytoplankton were resource limited during years of low biomass, we calculated an index of in situ population growth rate, PI = P,l(Z,B) where ~1' is the mean photosynthetic C assimilation rate in the photic zone (p' is primary productivity divided by Chl a biomass, assuming that Chl a is uniformly distributed over the shallow photic zone).…”

supporting

confidence: 93%

Trophic interactions and direct physical effects control phytoplankton biomass and production in an estuary

1992

View full text Add to dashboard Cite

The recent invasion of San Francisco Bay by the suspension-feeding clam Putamocorbula amurensis has provided an opportunity to document the ecological consequences of a major biological disturbance. Previous work over the last two decades has shown that phytoplankton biomass in the upper estuary is low (2-3 mg Chl a m-3) during seasonal periods of high river flow and short residence time, and it is usually high (peak > 30 mg Chl a m-3) during the summer-autumn seasons of low river flow and long residence time. However since P. amurensis became widespread and abundant in 1987, the summer phytoplankton biomass maximum has disappeared, presumably because of increased grazing pressure by this newly introduced species. For the period 1977-l 990, mean estimated primary production was only 39 g C mm2 yr-' during years when bivalve suspension feeders were abundant (>2,000 mm2), compared to 106 g C m-2 yr-' when bivalves were absent or present in low numbers. These observations support the hypothesis that seasonal and interannual fluctuations in estuarine phytoplankton biomass and primary production can be regulated jointly by direct physical effects (e.g. river-driven transport) and trophic interactions (episodes of enhanced grazing pressure by immigrant populations of benthic suspension feeders).

show abstract

“…The mean river freshwater flows in spring for wet, intermediate and dry years (Peterson et al, 1985) are shown as arrow heads drawn on the x-axis. The model in its present form suggests that dry and intermediate years should allow phytoplankton blooms (i.e.…”

Section: Comparison Of With-flow Model Results With Wet Versus Dry Yearsmentioning

confidence: 99%

“…The euphotic zone depth (1.05 m) was calculated from a mean Suisun Secchi depth of 0.3 m and the empirical relationship between Secchi depth and light attenuation coefficient as determined for Suisun Bay by Kimmerer et al (2012). The euphotic zone N uptake was scaled to the ratio of the euphotic zone depth to the mean depth of Suisun Bay (5.61 m) and provided in Peterson et al (1985). Horizontal dashed lines plotted are mean NH4 concentrations (for spring 1970-1974 and 1999-2003) or criterion extended to the 30 g L −1 contour and projected to the flow axis (x-axis).…”

Section: Model Runs With Variable Flow Fully Mixed Water Column Witmentioning

confidence: 99%

A biogeochemical model of phytoplankton productivity in an urban estuary: The importance of ammonium and freshwater flow

Dugdale

Wilkerson

Parker

2013

Ecological Modelling

View full text Add to dashboard Cite

a b s t r a c tIncreased discharge of ammonium (NH 4 ) to the San Francisco Estuary (SFE), largely in treated domestic sewage effluent, has been linked to chronically food-limited conditions and to reduced fish abundance. Elevated chlorophyll concentrations at phytoplankton bloom levels are rarely observed if the ambient NH 4 concentrations are above 4 mol L −1 -the NH 4 paradox. In both field samples and water held in enclosures for one week, an inverse relation was observed between NH 4 concentrations and nitrate (NO 3 ) uptake by phytoplankton, likely a result of inhibition of NO 3 uptake by NH 4 . A simple model was constructed to examine the interaction between NH 4 and NO 3 inputs to the estuary, with varying freshwater river flow (hereafter termed flow) conditions. Sensitivity analyses were made and initial model parameters taken from an existing oceanic biogeochemistry model. Experiments were made with the model, and showed that initial NH 4 concentrations largely controlled the length of time to peak NO 3 uptake and NO 3 exhaustion. The model parameters were then tuned using observations from a set of enclosure experiments, and validated with results from a series of independent enclosure experiments with a variety of initial conditions. The model was run in three flow modes: (1) with no (zero) flow, (2) with flow, a fully mixed water column and a uniform light field, and (3) with flow, a fully mixed water column but with light attenuation and depth integrated values of N uptake. In the zero flow mode the model simulated enclosure experiments and when compared with enclosure results indicated the basic NH 4 -NO 3 interactions to be correctly represented in the model. In the modes with flow, the model simulations reproduced a sharp transition from high phytoplankton productivity using both NO 3 and NH 4 to low productivity using only NH 4 , simulating the historical effects of increasing NH 4 inputs to the SFE. With vertical integration to incorporate effects of irradiance, sharp boundaries at specific combinations of varying flow and NH 4 inputs were observed. The model could be embedded into three dimensional models of the SFE/Delta currently being implemented for management purposes such as regulating estuarine nutrients as required by the State of California and evaluating the effects of water management decisions on salmon and protected species of fish.

show abstract

Interannual variability in dissolved inorganic nutrients in Northern San Francisco Bay Estuary

Cited by 43 publications

References 30 publications

The effect of inorganic nitrogen speciation on primary production in the San Francisco Estuary

The effect of inorganic nitrogen speciation on primary production in the San Francisco Estuary

Trophic interactions and direct physical effects control phytoplankton biomass and production in an estuary

A biogeochemical model of phytoplankton productivity in an urban estuary: The importance of ammonium and freshwater flow

Contact Info

Product

Resources

About