Variability in Nitrate Uptake Kinetics of Phytoplankton Communities in a Mediterranean Coastal Lagoon

Collos, Yves; Vaquer, André; Bibent, Bertrand; Slawyk, Gerd; Garcia, Nicole; Souchu, Philippe

doi:10.1006/ecss.1996.0121

Cited by 61 publications

(50 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this study we observed classical MichaeliseMenten kinetics for NH 4 but were unable to determine N uptake kinetics for NO 3 , although comparing rates obtained with saturating level of the two DIN species, there was higher V MAx for NO 3 compared to NH 4 . Deviation (to linear or biphasic) from the hyperbolic relationship for NO 3 uptake at saturating to supersaturating concentrations have been described in many algal species including diatoms (Serra et al, 1978;Watt et al, 1992;Collos et al, 1992Collos et al, , 1997Collos et al, , 2005Lomas and Glibert, 1999b) and upwelled phytoplankton . Two studies (Huntsman and Barber, 1977;Lancelot and Billen, 1985) showed that C and N uptake were coupled during linear NO 3 uptake at high concentrations.…”

Section: Maximal No 3 Uptake Exceeds Maximal Nh 4 Uptakementioning

confidence: 99%

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: Maximal No 3 Uptake Exceeds Maximal Nh 4 Uptakementioning

confidence: 99%

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

“…However, our data and a previous report (GIACOBBE et al, 1996) demonstrated the dominance of ammonia in the Bay of Tunis. The assimilation of ammonium by phytoplankton requires a lower metabolic energy than nitrate (COLLOS et al, 1997). EPPLEY et al (1969) asserted that ammonium levels higher than 2 ÌM induced almost maximal inhibition of nitrate uptake by phytoplankton.…”

Section: Species Response To Nutrient Variabilitymentioning

confidence: 99%

Spatio-temporal distribution of the dominant Diatom and Dinoflagellate species in the Bay of Tunis (SW Mediterranean Sea)

et al. 2005

View full text Add to dashboard Cite

Microphytoplankton composition and its relationships with hydrology and nutrient distributions were investigated over 24 months (December 1993 -November 1995 in the Bay of Tunis (SW Mediterranean Sea). A new index, the 'Specific Preference Index' (SPI) obtained by computing the median value of each parameter weighed by the numerical value of each species density was developed. Using this index, the relationships between each species and temperature, salinity and major nutrients were analysed.The distribution of chlorophyll a did not show a clear correlation with microplankton abundance suggesting that other factors contribute to chlorophyll concentration, such as smaller phytoplankton size fractions or detritus. The winter-spring diatom blooms did not show a regular pattern during both years. High nutrient inputs in late summer, associated with mild meteorological conditions, contributed to the development of a large diatom bloom in autumn 1995 where significant silicate depletion was witnessed. Generally, diatoms were more stenotherm than dinoflagellates in the Bay, whereas dinoflagellates were more stenohaline than diatoms. The statistical analyses showed that the two species, Bellerochea horologicalis and Lithodesmioides polymorpha var. tunisiense, appeared in a wide range of environmental conditions. An excess of phosphate versus nitrate appeared to be associated with red tides of Gymnodinium spp, whereas Peridinium quinquecorne showed the opposite. Phosphate concentrations appear to be crucial in this coastal environment, where diatom blooms are often limited by low silicate availability.

show abstract

“…Field studies have demonstrated that microalgal taxa prefer particular forms of a given nutrient element (Berg et al 1997, 2003a, Lomas et al 1996). For example, Aureococcus anophagefferens has been shown to proliferate faster in NH 4 + or urea-amended water than in water with NO 3 -amendments, while diatoms tend to grow fastest in waters with high NO 3 -fluxes (Berg et al 1997, Collos et al 1997). The present study examines the hypothesis that nitrogen speciation in Long Island embayments controls phytoplankton community composition through resource competition.…”

Section: Introductionmentioning

confidence: 99%

Speciation and concentrations of dissolved nitrogen as determinants of brown tide Aureococcus anophagefferens bloom initiation

Taylor

Gobler²,

Sañudo‐Wilhelmy³

2006

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Growth responses of the brown tide organism Aureococcus anophagefferens and 4 cooccurring microalgal species to varying concentrations of nitrate, ammonium, urea, and glutamate were assayed in laboratory experiments. Analogous to seasonal shifts in nutrient regimes in local bays, growth functional responses were used to predict relative species abundances in simulated communities supported by a reduced nitrogen source after cultivation on NO 3 -. Simulations were based on Monod kinetic parameters, lagged growth responses and threshold nutrient concentrations. Presented with NO 3 -only, rank order of biomass production was Thalassiosira pseudonana > Nannochloris atomus > Synechococcus bacillaris > Prorocentrum minimum > A. anophagefferens at all concentrations. In contrast, model communities offered NH 4 + or glutamate at most environmental concentrations (1 to 50 µM N) tended to be dominated by A. anophagefferens and P. minimum. Over environmental ranges of urea concentrations (1 to 50 µM N), T. pseudonana grew fastest, followed by A. anophagefferens. In field validation experiments, bay water with bloom concentrations of A. anophagefferens (10 5 cells ml -1) amended with equimolar (total N) nitrate-rich groundwater or reduced N-rich sediment porewater supported equal increases in total chlorophyll a through time. However, porewater selectively stimulated A. anophagefferens growth more than groundwater, and the converse was observed for cyanobacteria. Extrapolation of all experimental results to conditions in Long Island embayments suggests that phytoplankton communities supplied primarily with NO 3 -will be dominated by diatoms, such as T. pseudonana, and perhaps by chlorophytes and cyanobacteria like N. atomus and S. bacillaris. Conversely, phytoplankton communities primarily supplied with low-to-moderate concentrations of reduced N-species, NH 4 + , and dissolved organic nitrogen (DON) will be dominated by A. anophagefferens and, to a lesser extent, dinoflagellates like P. minimum. Our results are consistent with published field observations of A. anophagefferens bloom dynamics in Long Island estuaries.KEY WORDS: Aureococcus anophagefferens · Bottom-up control · Brown tide · Nitrogen uptake · Pelagophyceae · Submarine groundwater discharge Resale or republication not permitted without written consent of the publisher

show abstract

Variability in Nitrate Uptake Kinetics of Phytoplankton Communities in a Mediterranean Coastal Lagoon

Cited by 61 publications

References 33 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

Spatio-temporal distribution of the dominant Diatom and Dinoflagellate species in the Bay of Tunis (SW Mediterranean Sea)

Speciation and concentrations of dissolved nitrogen as determinants of brown tide Aureococcus anophagefferens bloom initiation

Contact Info

Product

Resources

About