scholarly journals A stochastic, Lagrangian model of sinking biogenic aggregates in the ocean (SLAMS 1.0): model formulation, validation and sensitivity

2016 ◽  
Vol 9 (4) ◽  
pp. 1455-1476 ◽  
Author(s):  
Tinna Jokulsdottir ◽  
David Archer
Keyword(s):  
Primary Production ◽  
Degradation Kinetics ◽  
Mechanistic Model ◽  
Euphotic Zone ◽  
Lagrangian Model ◽  
Zooplankton Grazing ◽  
Aggregate Model ◽  
Size Spectra ◽  
Sea Floor ◽  
Individual Particles

Abstract. We present a new mechanistic model, stochastic, Lagrangian aggregate model of sinking particles (SLAMS) for the biological pump in the ocean, which tracks the evolution of individual particles as they aggregate, disaggregate, sink, and are altered by chemical and biological processes. SLAMS considers the impacts of ballasting by mineral phases, binding of aggregates by transparent exopolymer particles (TEP), zooplankton grazing and the fractal geometry (porosity) of the aggregates. Parameterizations for age-dependent organic carbon (orgC) degradation kinetics, and disaggregation driven by zooplankton grazing and TEP degradation, are motivated by observed particle fluxes and size spectra throughout the water column. The model is able to explain observed variations in orgC export efficiency and rain ratio from the euphotic zone and to the sea floor as driven by sea surface temperature and the primary production rate and seasonality of primary production. The model provides a new mechanistic framework with which to predict future changes on the flux attenuation of orgC in response to climate change forcing.

scholarly journals A Stochastic, Lagrangian Model of Sinking biogenic aggregates in the ocean (SLAMS 1.0): model formulation, validation and sensitivity

2015 ◽  
Vol 8 (7) ◽  
pp. 5931-5982 ◽  
Author(s):  
T. Jokulsdottir ◽  
D. Archer
Keyword(s):  
Primary Production ◽  
Degradation Kinetics ◽  
Mechanistic Model ◽  
Euphotic Zone ◽  
Lagrangian Model ◽  
Zooplankton Grazing ◽  
Aggregate Model ◽  
Size Spectra ◽  
Sea Floor ◽  
Individual Particles

Abstract. We present a new mechanistic model, Stochastic Lagrangian Aggregate Model of Sinking particles (SLAMS) for the biological pump in the ocean, which tracks the evolution of individual particles as they aggregate, disaggregate, sink, and are altered by chemical and biological processes. SLAMS considers the impacts of ballasting by mineral phases, binding of aggregates by transparent exopolymer particles (TEP), zooplankton grazing, and the fractal geometry (porosity) of the aggregates. Parameterizations for age-dependent organic carbon (orgC) degradation kinetics, and disaggregation driven by zooplankton grazing and TEP degradation, are motivated by observed particle fluxes and size spectra throughout the water column. The model is able to explain observed variations in orgC export efficiency and rain ratio from the euphotic zone and to the sea floor as driven by sea surface temperature and the primary production rate and seasonality of primary production. The model provides a new mechanistic framework with which to predict future changes on the flux attenuation of orgC in response to climate change forcing.

Primary Production and Phytoplankton in the Experimental Lakes Area, Northwestern Ontario, and other Low-Carbonate Waters, and a Liquid Scintillation Method for Determining 14C Activity in Photosynthesis

1971 ◽  
Vol 28 (2) ◽  
pp. 189-201 ◽  
Author(s):  
D. W. Schindler ◽  
S. K. Holmgren
Keyword(s):  
Primary Production ◽  
Liquid Scintillation ◽  
Species Abundance ◽  
Euphotic Zone ◽  
Phytoplankton Production ◽  
Phytoplankton Species ◽  
Experimental Lakes Area ◽  
Phytoplankton Species Composition ◽  
Northwestern Ontario ◽  
Filtration Error

A modified 14C method is described for measuring phytoplankton production in low-carbonate waters. The procedure includes the use of the Arthur and Rigler (Limnol. Oceanogr. 12: 121–124, 1967) technique for determining filtration error, liquid scintillation counting for determining the radioactivity of membrane filters and stock 14C solutions, and gas chromatography for measuring total CO2.Primary production, chlorophyll a, and total CO2 were measured for two dates in midsummer from each of several lakes in the Experimental Lakes Area (ELA), ranging from 1 to 1000 ha in area and from 2 to 117 m in maximum depth. Phytoplankton species abundance and biomass were determined for the same dates. Production ranged from 0.02 to 2.12 gC/m3∙day and from 0.179 to 1.103 g C/m2∙day. Chlorophyll ranged from 0.4 to 44 mg/m3 and from 5 to 98 mg/m2 in the euphotic zone. The corresponding ranges for live phytoplankton biomass were 120–5400 mg/m3 and 2100–13,400 mg/m2. Chrysophyceae dominated the phytoplankton of most of the lakes.A system for classifying the lakes in terms of phytoplankton species composition and production–depth curves is developed.

Quantum yield of the marine benthic microflora of near-shore coastal Penang, Malaysia

2005 ◽  
Vol 56 (7) ◽  
pp. 1047 ◽  
Author(s):  
A. McMinn ◽  
S. Sellah ◽  
W. A. Wan Ab. Llah ◽  
M. Mohammad ◽  
F. Md. Sidik Merican ◽  
...  
Keyword(s):  
Primary Production ◽  
Suspended Solids ◽  
Euphotic Zone ◽  
Water Clarity ◽  
Quantum Yields ◽  
Chl A ◽  
Near Shore ◽  
High Concentrations ◽  
A Minor ◽  
Reduced Water

Benthic microalgal communities often contribute more than 30% of the primary production of shallow coastal and estuarine areas. At Muka Head Penang (Pulau Pinang) and the Songsong Islands (Pulau Songsong), Kedah, Malaysia, high concentrations of suspended solids and phytoplankton biomass (10.6 mg Chl a m−3) has reduced water clarity such that the euphotic zone of these areas is less than 2 m and 3 m deep respectively. The benthic microalgal communities, which were composed of the diatom genera Cocconeis, Fragilaria, Paralia and Pleurosigma, had a low biomass, had low maximum quantum yields (0.325 ± 0.129), were poorly adapted to their light environment and were constantly light limited. These characteristics suggest that the benthic microalgal communities were likely to have made only a minor contribution to the total primary production of the area.

New and regenerated primary production in a productive reservoir ecosystem

2010 ◽  
Vol 67 (2) ◽  
pp. 278-287 ◽  
Author(s):  
Leah M. Domine ◽  
Michael J. Vanni ◽  
William H. Renwick
Keyword(s):  
Primary Production ◽  
Euphotic Zone ◽  
Gizzard Shad ◽  
Phytoplankton Production ◽  
Total Production ◽  
Relative Importance ◽  
Dorosoma Cepedianum ◽  
New Production ◽  
Total Primary Production ◽  
The Difference

The concept of new and regenerated production has been used extensively in marine ecosystems but rarely in freshwaters. We assessed the relative importance of new and regenerated phosphorus (P) in sustaining phytoplankton production in Acton Lake, a eutrophic reservoir located in southwestern Ohio, USA. Sources of nutrients to the euphotic zone, including watershed loading, fluxes from sediments, and excretion by sediment-feeding fish (gizzard shad, Dorosoma cepedianum ), were considered sources of new P input that support new primary production and were quantified over the course of a growing season. Regenerated production was estimated by the difference between new and total primary production. New production represented 32%–53% of total primary production, whereas regenerated production represented 47%–68% of total primary production. P excretion by gizzard shad supplied 45%–74% of new P and 24% of P required for total production. In summary, fluxes of P from the watershed and those from sediment-feeding fish need to be considered in strategies to reduce eutrophication in reservoir ecosystems.

Intra-annual upwelling patterns and its linkage with primary production in the euphotic zone (24.5°N) of Southern Baja California coast

2015 ◽  
Vol 157 ◽  
pp. 51-58 ◽  
Author(s):  
Rafael Cervantes-Duarte ◽  
Ricardo Prego ◽  
Gilberto Gaxiola-Castro ◽  
Silverio López-López ◽  
Fernando Aguirre-Bahena ◽  
...  
Keyword(s):  
Primary Production ◽  
Baja California ◽  
Euphotic Zone ◽  
California Coast

Chemosynthetic Primary Production at East Pacific Sea Floor Spreading Centers

BioScience ◽  
1979 ◽  
Vol 29 (10) ◽  
pp. 592-598 ◽  
Author(s):  
Holger W. Jannasch ◽  
Carl O. Wirsen
Keyword(s):  
Primary Production ◽  
Sea Floor ◽  
East Pacific ◽  
Spreading Centers ◽  
Sea Floor Spreading

scholarly journals Changes in the Adriatic oceanographic properties induced by the Eastern Mediterranean Transient

2012 ◽  
Vol 9 (1) ◽  
pp. 927-956 ◽  
Author(s):  
I. Vilibić ◽  
S. Matijević ◽  
J. Šepić
Keyword(s):  
Primary Production ◽  
Eastern Mediterranean ◽  
Euphotic Zone ◽  
N:P Ratio ◽  
Western Mediterranean ◽  
Fish Stock ◽  
Trophic Chain ◽  
Average Water ◽  
Physical And Chemical

Abstract. Long-term time series of physical and chemical parameters collected between 1960 and 2010 along the Palagruža Sill transect, middle Adriatic Sea, have been investigated in terms of average water properties and their variability. Nutrients, especially orthophosphates, reached rather higher levels of concentration below the euphotic zone between 1991 and 1998, the highest in the investigated period. Simultaneously, the N:P ratio, which is normally larger than 25:1, decreased to values less than 16:1 in the euphotic zone, indicating a switch from typical phosphorus-limited to nitrogen-limited preconditioning of the primary production. Higher-than-usual nutrient levels, coupled with lower-than-usual temperature, salinity and dissolved oxygen, have been attributed to the intermediate inflow of the nutrient richer Western Mediterranean waters to the Adriatic, entering the Adriatic during the anticyclonic phase of the Bimodal Adriatic-Ionian Oscillation (BiOS). The BiOS and the Northern Ionian anticyclone have been uniquely strengthened by the Eastern Mediterranean Transient occurring in the early 1990s. The observed changes have a potential to impact the primary production and presumably the whole trophic chain in the Adriatic and were likely responsible for the observed fluctuation in abundances of various species and fish stock, indicating a high relevance of the observed physical processes.

scholarly journals Rates of primary production in groundwater rival those in oligotrophic marine systems

2021 ◽  
Author(s):  
Will A Overholt ◽  
Susan Trumbore ◽  
Xiaomei Xu ◽  
Till L V Bornemann ◽  
Alexander J Probst ◽  
...  
Keyword(s):  
Primary Production ◽  
Surface Waters ◽  
Carbon Fixation ◽  
Euphotic Zone ◽  
Rate Data ◽  
Carbonate Aquifer ◽  
Marine Systems ◽  
Marine Surface ◽  
Terrestrial Subsurface

The terrestrial subsurface contains nearly all of Earth's freshwater reserves and harbors upwards of 60% of our planet's total prokaryotic biomass. While genetic surveys suggest these organisms rely on in situ carbon fixation, rather than the translocation of photosynthetically derived organic carbon, corroborating measurements of carbon fixation in the subsurface are absent. Using a novel ultra-low level 14C-labeling technique, we show that in situ carbon fixation rates in a carbonate aquifer reached 10% of the median rates measured in oligotrophic marine surface waters, and were up to six-fold greater than those observed in lower euphotic zone waters where deep chlorophyll levels peak. Empirical carbon fixation rates were substantiated by both nitrification and anammox rate data. Metagenomic analyses revealed a remarkable abundance of putative chemolithoautotrophic members of an uncharacterized order of Nitrospiria - the first representatives of this class expected to fix carbon via the Wood-Ljungdahl pathway. Based on these fixation rates, we extrapolate global primary production in carbonate groundwaters to be 0.11 Pg of carbon per year.

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