Living benthic foraminifera of Santos continental shelf, southeastern Brazilian continental margin (SW Atlantic): chlorophyll-a and particulate organic matter approach

2020 ◽  
Vol 5 (1) ◽  
pp. 17-34 ◽  
Author(s):  
Cintia Yamashita ◽  
Cláudia Omachi ◽  
Ana Cláudia Aoki Santarosa ◽  
Fabiane Sayuri Iwai ◽  
Beatriz Dias Araujo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Continental Shelf ◽  
Chlorophyll A ◽  
Particulate Organic Matter ◽  
Continental Margin ◽  
Benthic Foraminifera ◽  
Sw Atlantic

Element partitioning in ferruginous and pyritic phosphorite from the continental margin off Morocco

1978 ◽  
Vol 42 (322) ◽  
pp. 221-228 ◽  
Author(s):  
J. M. McArthur
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Continental Shelf ◽  
Continental Margin ◽  
Major Elements ◽  
Element Partitioning ◽  
Carbonate Fluorapatite

SummaryPhosphorites from the continental shelf off Morocco have been analysed for major elements and Fe, Mn, V, Cu, Ni, Zn, As, Na, Sr, S, and for carbonate. In pyritic phosphorites Cu, Ni, Zn, and As are present mainly in minor pyrite and organic carbon. In ferruginous phosphorites As, Mn, and V are associated with goethite. In the ferruginous phosphorites Cu, Ni, and Zn may have been introduced in association with organic matter and pyrite during phosphorite formation and been retained during subsequent destruction of these phases by weathering. In all phosphorites Na and Sr are present mainly in carbonate-fluorapatite. Sulphur in the ferru-ginous phosphorites occurs only in carbonate-fluorapatite. In the pyritic samples it is partitioned between pyrite and francolite (carbonate-fluorapatite).

Energy Flow Between the Pelagic and Benthic Zones: Factors Controlling Particulate Organic Matter Available to an Intertidal Mussel Bed

1985 ◽  
Vol 42 (6) ◽  
pp. 1158-1165 ◽  
Author(s):  
Marcel Fréchette ◽  
Edwin Bourget
Keyword(s):  
Organic Matter ◽  
Chlorophyll A ◽  
Particulate Organic Matter ◽  
Wave Energy ◽  
Wave Amplitude ◽  
Water Movement ◽  
Tidal Energy ◽  
Mussel Bed ◽  
Tidal Cycles ◽  
Intertidal Mussel

Fluctuations and vertical gradients of particulate organic matter (POM, as indicated by chlorophyll a and phaeopigments) concentration over an intertidal mussel bed were studied over fortnightly tidal cycles. Chlorophyll a variations were not associated with wave amplitude, tidal energy, and sigma-t, and phaeopigment concentration was correlated positively with wave amplitude only. Comparison of total pigment concentration in water pumped simultaneously from within 5 cm and from 50 cm above the mussel bed showed significant depletion of POM nearest to the mussel bed throughout the first of the two fortnightly tidal cycles studied. During this period, POM depletion was negatively correlated with current speed, but not with mussel filtration rate, nor with wave energy. During the other period, POM depletion was significant in three of the six semidiurnal tidal cycles studied, and depletion was negatively correlated with wave energy only. Our data indicate that food is often depleted immediately above mussel populations, and that water movement is critical in determining food availability for suspension feeders.

Distribution of living benthic foraminifera in relation with environmental variables within the Aiguillon cove (Atlantic coast, France): improving knowledge for paleoecological interpretation

2009 ◽  
Vol 180 (2) ◽  
pp. 131-144 ◽  
Author(s):  
Eric Armynot du Chatelet ◽  
Delphine Degre ◽  
Pierre-Guy Sauriau ◽  
Jean-Pierre Debenay
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Chlorophyll A ◽  
Benthic Foraminifera ◽  
Environmental Variables ◽  
Organic Matter Content ◽  
Distribution Patterns ◽  
Tidal Elevation ◽  
Sediment Grain Size ◽  
Organic Matter Quality

Abstract Search for bioindicators in marine environments has provided new tools for monitoring global and local natural changes. Among these tools, benthic foraminifera play a central role. More accurate paleogeographical and paleoecological reconstructions become possible on the basis of the ecology of recent foraminifera. Nevertheless, factors acting on foraminiferal assemblages are still partially understood. The aim of this study is to correlate the distribution patterns of living (stained) benthic foraminifera with environmental variables such as tidal elevation, interstitial pore water salinity, organic matter content of the sediment, pheopigments, chlorophyll a, carbonate contents and grain size distribution of the sediment from 86 samples collected in the Aiguillon cove (France). In this paralic environment, sediment grain size, salinity and tidal elevation are fundamental factors that drive the distribution of the most abundant species i.e. Brizalina variabilis, Cribroelphidium excavatum and Haynesina germanica. Organic matter also influences the distribution patterns of benthic foraminifera: the relative abundance of Ammonia tepida is typically favored by an increase of total organic matter food resources. Chlorophyll a and pheopigments, as indicators of organic matter quality however may not be limiting in the proportion present in the Aiguillon cove. Carbonate proportions do not limit benthic foraminifera of the Aiguillon cove essentially with carbonaceous shells.

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