scholarly journals Dissolved inorganic nitrogen, chlorophyll-a, and primary production from bioassay experiments during the R/V Hugh R. Sharp cruise HRS1414 in the Mid and South-Atlantic Bight in August of 2014 (DANCE project)

2018 ◽  
Author(s):  
Peter Sedwick ◽  
Margaret Mulholland ◽  
Raymond Najjar
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Inorganic Nitrogen ◽  
South Atlantic ◽  
South Atlantic Bight ◽  
Dissolved Inorganic Nitrogen

scholarly journals Instantaneous transport of salt, nutrients, suspended matter and chlorophyll-a in the tropical estuarine system of Santos

2005 ◽  
Vol 53 (3-4) ◽  
pp. 115-127 ◽  
Author(s):  
Gleyci A. O. Moser ◽  
Sônia Maria Flores Gianesella ◽  
José Juan Barrera Alba ◽  
Alessandro Luvizon Bérgamo ◽  
Flávia M. P. Saldanha-Corrêa ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Rainy Season ◽  
Inorganic Nitrogen ◽  
Austral Summer ◽  
Estuarine System ◽  
Austral Winter ◽  
Dissolved Inorganic Nitrogen ◽  
Chl A ◽  
Inorganic Matter ◽  
Tropical Estuarine

The contribution of the polluted São Vicente and Santos estuarine channels to the eutrophication of Santos bay was assessed through the quantification of instantaneous transport of salt, dissolved inorganic nitrogen (DIN) and phosphate, organic and inorganic matter (OSM and ISM) and chlorophyll-a (Chl-a), during dry (austral winter- August/ 1999) and rainy (austral summer- January/2000) seasons. Samplings were carried out during spring and neap tides, in flood and ebb phases, in two transversal sections at the mouths of the São Vicente and Santos channels. Instantaneous transport values generally indicated importation of salt to the estuarine channels, exportation of DIN to the bay, mainly as N-NH4, at a maximum rate of 1155.1 g s-1 during the rainy season; importation of phosphate during the dry season (maximum of 385 g s-1) and exportation of ISM, OSM and Chl-a during periods of greater freshwater discharge. These results demonstrate the great contribution made by the Santos and São Vicente estuaries to the eutrophication of Santos bay, especially in the rainy season.

scholarly journals Atmospheric Deposition of Macronutrients (Dissolved Inorganic Nitrogen and Phosphorous) onto the Black Sea and Implications on Marine Productivity*

2016 ◽  
Vol 73 (4) ◽  
pp. 1727-1739 ◽  
Author(s):  
M. Koçak ◽  
N. Mihalopoulos ◽  
E. Tutsak ◽  
K. Violaki ◽  
C. Theodosi ◽  
...  
Keyword(s):  
Primary Production ◽  
Atmospheric Deposition ◽  
Black Sea ◽  
Inorganic Nitrogen ◽  
Phosphate Concentration ◽  
Rural Site ◽  
The Black Sea ◽  
Dissolved Inorganic Nitrogen ◽  
N:P Ratios ◽  
The Mean

Abstract Two-sized aerosol samples were obtained from a rural site located close to Sinop on the south coastline of the Black Sea. In addition, bulk deposition samples were collected at Varna, located on the west coastline of the Black Sea. Both aerosol and deposition samples were analyzed for the main macronutrients, NO3−, NH4+, and PO43−. The mean aerosol nitrate and ammonium concentrations were 7.1 ± 5.5 and 22.8 ± 17.8 nmol m−3, respectively. The mean aerosol phosphate concentration was 0.69 ± 0.31 nmol m−3, ranging from 0.21 to 2.36 nmol m−3. Interestingly, phosphate concentration over Sinop was substantially higher than those of most Mediterranean sites. Comparison of the atmospheric and riverine inputs for the Black Sea revealed that atmospheric dissolved inorganic nitrogen (DIN) only ranged between 4% and 13%, while the atmospheric dissolved inorganic phosphorus (DIP) fluxes had significantly higher contributions with values ranging from 12% to 37%. The molar N:P ratios in atmospheric deposition for Sinop and Varna were 13 and 14, respectively, both of which were lower than the Redfield ratio (16). The atmospheric molar N:P ratios over the Black Sea were considerably lower than those reported for riverine fluxes (41) and the Mediterranean region (more than 200). The atmospheric P flux can sustain 0.5%–5.2% of the primary production, whereas the N flux can sustain 0.4%–4.8% of the primary production. The contribution of the atmospheric flux may enhance by 2.6 when the new production is considered.

scholarly journals Phytoplankton biomass dynamics and environmental variables around the Rocas Atoll Biological Reserve, South Atlantic

2015 ◽  
Vol 63 (4) ◽  
pp. 443-454 ◽  
Author(s):  
Marina Cavalcanti Jales ◽  
Fernando Antônio do Nascimento Feitosa ◽  
Maria Luise Koening ◽  
Manuel de Jesus Flores Montes ◽  
Moacyr Cunha de Araújo Filho ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Mixed Layer ◽  
Environmental Variables ◽  
Phytoplankton Biomass ◽  
Inorganic Nitrogen ◽  
Principal Component ◽  
Inorganic Phosphorus ◽  
Mean Value ◽  
South Atlantic ◽  
Biological Reserve

Abstract The Rocas Atoll Biological Reserve is located in the Atlantic Ocean, at 3º 51' S and 33º 49' W. It lies 143 nautical miles from the City of Natal, Rio Grande do Norte (Brazil). The purpose of this study was to analyze the hydrology, water masses, currents and chlorophyll a content to determine the dynamics of phytoplankton biomass around the Rocas Atoll. Samples were collected in July 2010 in the area around the Atoll, using the Research Vessel Cruzeiro do Sul of the Brazilian Navy. Two transects were established according to the surface currents, one of which at the southeast of the Atoll (SE) and the other at norwest (NW). Three collection points were determined on each of these transects. Samples were collected at different depths (surface and DCM - Deep Chlorophyll Maximum) and different times (day and night). According to PCA (Principal Component Analysis), the nutrients analyzed, DIN (dissolved inorganic nitrogen), DIP (dissolved inorganic phosphorus) and silicate, were inversely correlated with temperature and dissolved oxygen. Most environmental variables showed a significant increase due to the turbulence on the Northwest transect. There was an increase in the concentration of chlorophyll a and nutrients when the temperature and oxygen in the mixed layer was reduced due to the influence of the SACW (South Atlantic Central Water). Despite the increase observed in some variables such as nutrient salts and chlorophyll a, the temperature in the mixed layer attained a mean value of 23.23 ºC due to the predominance of Tropical Water. The increase of the phytoplankton biomass on the NW transect was, therefore, caused by the "island effect" and not by upwelling.

scholarly journals Response of Lower Sacramento River phytoplankton to high-ammonium wastewater effluent

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Aaron L. Strong ◽  
Matthew M. Mills ◽  
Ivy B. Huang ◽  
Gert L. van Dijken ◽  
Sara E. Driscoll ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Primary Production ◽  
San Francisco ◽  
Growth Rates ◽  
Wastewater Treatment Plant ◽  
Inorganic Nitrogen ◽  
Treatment Plant ◽  
Wastewater Effluent ◽  
Dissolved Inorganic Nitrogen ◽  
Wastewater Treatment Plant Effluent

Since the 1980s, the San Francisco Bay Delta ecosystem has experienced large declines in primary production. Hypothesized reasons for this decline include (1) suppression of nitrate (NO3−) uptake, and thus phytoplankton growth, due to high concentrations of ammonium (NH4+), and (2) wastewater NH4+-induced changes in phytoplankton community composition away from large-celled diatoms. These twin hypotheses implicate NH4+ loading from the Sacramento Regional Wastewater Treatment Plant effluent outfall in explaining declines in primary production in the region. They have been controversial within the water resources management community and have stimulated a lengthy public scientific and regulatory debate. Here, in an effort to resolve this debate, we present results from a 48-h incubation experiment with surface water from both upstream and downstream of the Sacramento Regional Wastewater Treatment Plant effluent outfall, a major source of NH4+ loading to the ecosystem. We amended this water with either NH4+, NO3−, or full wastewater effluent. All assays were incubated under high light (52% of incident irradiance) or low light (6% of incident irradiance). NO3− uptake rates were suppressed to near zero in all treatments with either added NH4+, added wastewater effluent, or high in situ NH4+ concentrations. Yet, phytoplankton uniformly grew well on all dissolved inorganic nitrogen sources, including effluent and NH4+. Diatom species were the most abundant taxa at all stations, and diatom cell abundances increased at greater rates than all other taxa over the course of the experiment. Among all treatments, the light treatment had the greatest effects on chlorophyll a accumulation and phytoplankton growth rates. Our results suggest that high NH4+ loading is not a driver of the lower productivity in the San Francisco Bay Delta. Although phytoplankton preferred NH4+ to NO3− when both were available in our experiment, the form of dissolved inorganic nitrogen had no effect on growth rates or species composition.

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