Short contributions to Alaskan trace element studies 1946 : Part II: Trace elements reconnaissance of the South Fork of Quartz Creek, northeastern Seward Peninsula, Alaska

1950 ◽  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
South Fork ◽  
The South ◽  
Seward Peninsula

scholarly journals Radium-228-derived ocean mixing and trace element inputs in the South Atlantic

2020 ◽  
Author(s):  
Yu-Te Hsieh ◽  
Walter Geibert ◽  
E. Malcolm S. Woodward ◽  
Neil J. Wyatt ◽  
Maeve C. Lohan ◽  
...  
Keyword(s):  
Trace Elements ◽  
Continental Shelf ◽  
Trace Element ◽  
Vertical Mixing ◽  
South Atlantic ◽  
Open Ocean ◽  
The South ◽  
Horizontal Mixing ◽  
Cape Basin ◽  
Argentine Basin

Abstract. Trace elements play important roles as micronutrients in modulating marine productivity in the global ocean. The South Atlantic around 40° S is a prominent region of high productivity and a transition zone between the nitrate-depleted Subtropical Gyre and the iron-limited Southern Ocean. However, the sources and fluxes of trace elements to this region remain unclear. In this study, the distribution of the naturally occurring radioisotope 228Ra in the water column of the South Atlantic (Cape Basin and Argentine Basin) has been investigated along a 40° S zonal transect to estimate ocean mixing and trace element supply to the surface ocean. Ra-228 profiles have been used to determine the horizontal and vertical mixing rates in the near-surface open ocean. In the Argentine Basin, horizontal mixing from the continental shelf to the open ocean shows an eddy diffusion of Kx = 1.7 ± 1.4 (106 cm2 s−1) and an integrated advection velocity w = 0.6 ± 0.3 cm s−1. In the Cape Basin, horizontal mixing is Kx = 2.7 ± 0.8 (107 cm2 s−1) and vertical mixing Kz = 1.0–1.5 cm2 s−1 in the upper 600 m layer. Three different approaches (228Ra-diffusion, 228Ra-advection and 228Ra/TE-ratio) have been applied to estimate the dissolved trace-element fluxes from shelf to open ocean. These approaches bracket the possible range of off-shelf fluxes from the Argentine margin to be: 3.8–22 (× 103) nmol Co m−2 d−1, 7.9–20 (× 104) nmol Fe m−2 d−1 and 2.7–6.5 (× 104) nmol Zn m−2 d−1. Off-shelf fluxes from the Cape margin are: 4.3–6.2 (× 103) nmol Co m−2 d−1, 1.2–3.1 (× 104) nmol Fe m−2 d−1 and 0.9–1.2 (× 104) nmol Zn m−2 d−1. On average, at 40° S in the Atlantic, vertical mixing supplies 0.4–1.2 nmol Co m−2 d−1, 3.6–11 nmol Fe m−2 d−1, and 13–16 nmol Zn m−2 d−1 to the euphotic zone. Compared with atmospheric dust and continental shelf inputs, vertical mixing is a more important source for supplying dissolved trace elements to the surface 40° S Atlantic. It is insufficient, however, to provide the trace elements removed by biological uptake. Other inputs (e.g. particulate, or from winter deep-mixing) are required to balance the trace element budgets in this region.

scholarly journals Radium-228-derived ocean mixing and trace element inputs in the South Atlantic

2021 ◽  
Vol 18 (5) ◽  
pp. 1645-1671
Author(s):  
Yu-Te Hsieh ◽  
Walter Geibert ◽  
E. Malcolm S. Woodward ◽  
Neil J. Wyatt ◽  
Maeve C. Lohan ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Vertical Mixing ◽  
South Atlantic ◽  
Open Ocean ◽  
The South ◽  
Horizontal Mixing ◽  
Cape Basin ◽  
Argentine Basin ◽  
Basin Margin

Abstract. Trace elements (TEs) play important roles as micronutrients in modulating marine productivity in the global ocean. The South Atlantic around 40∘ S is a prominent region of high productivity and a transition zone between the nitrate-depleted subtropical gyre and the iron-limited Southern Ocean. However, the sources and fluxes of trace elements to this region remain unclear. In this study, the distribution of the naturally occurring radioisotope 228Ra in the water column of the South Atlantic (Cape Basin and Argentine Basin) has been investigated along a 40∘ S zonal transect to estimate ocean mixing and trace element supply to the surface ocean. Ra-228 profiles have been used to determine the horizontal and vertical mixing rates in the near-surface open ocean. In the Argentine Basin, horizontal mixing from the continental shelf to the open ocean shows an eddy diffusion of Kx=1.8±1.4 (106 cm2 s−1) and an integrated advection velocity w=0.6±0.3 cm s−1. In the Cape Basin, horizontal mixing is Kx=2.7±0.8 (107 cm2 s−1) and vertical mixing Kz = 1.0–1.7 cm2 s−1 in the upper 600 m layer. Three different approaches (228Ra diffusion, 228Ra advection, and 228Ra/TE ratio) have been applied to estimate the dissolved trace element fluxes from the shelf to the open ocean. These approaches bracket the possible range of off-shelf fluxes from the Argentine Basin margin to be 4–21 (×103) nmol Co m−2 d−1, 8–19 (×104) nmol Fe m−2 d−1 and 2.7–6.3 (×104) nmol Zn m−2 d−1. Off-shelf fluxes from the Cape Basin margin are 4.3–6.2 (×103) nmol Co m−2 d−1, 1.2–3.1 (×104) nmol Fe m−2 d−1, and 0.9–1.2 (×104) nmol Zn m−2 d−1. On average, at 40∘ S in the Atlantic, vertical mixing supplies 0.1–1.2 nmol Co m−2 d−1, 6–9 nmol Fe m−2 d−1, and 5–7 nmol Zn m−2 d−1 to the euphotic zone. Compared with atmospheric dust and continental shelf inputs, vertical mixing is a more important source for supplying dissolved trace elements to the surface 40∘ S Atlantic transect. It is insufficient, however, to provide the trace elements removed by biological uptake, particularly for Fe. Other inputs (e.g. particulate or from winter deep mixing) are required to balance the trace element budgets in this region.

Methylmercury and Trace Element Distribution in the Organs of Stenella coeruleoalba Dolphins Stranded on the French Mediterranean Coast

2014 ◽  
Vol 8 (1) ◽  
pp. 35-48 ◽  
Author(s):  
Emmanuel Wafo ◽  
Véronique Risoul ◽  
Thérèse Schembri ◽  
Véronique Lagadec ◽  
Frank Dhermain ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Marine Pollution ◽  
Element Distribution ◽  
Mediterranean Coast ◽  
Trace Element Distribution ◽  
Slight Reduction ◽  
Stenella Coeruleoalba ◽  
Contamination Levels

The main objective of this study was to evaluate the contamination by mercury (Hg), methylmercury (Me-Hg), cadmium (Cd), selenium (Se), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) in dolphins stranded on the French Mediterranean coast. The distributions of these contaminants in the organs of dolphins have also been studied. Overall, contamination levels varied according to the following sequence: liver > kidney > lung > muscle, except for cadmium (kidney > liver > lung > muscle). Size and sex of animals were also considered. Young dolphins were less impacted with trace elements than adults, except for copper. Among the studied parameters, the most important appeared to be the size of mammals. In addition, in the case of mercury and selenium, the sex of mammals seemed to be also relevant. The correlations between the concentrations of trace elements suggest the existence of detoxification processes. Since 1990s, using dolphins for tracing marine pollution, a slight reduction in the burden of the considered trace elements could be noted.

scholarly journals Spatial distribution and potential ecological risk assessment of some trace elements in sediments and grey mangrove (Avicennia marina) along the Arabian Gulf coast, Saudi Arabia

2020 ◽  
Vol 18 (1) ◽  
pp. 77-96
Author(s):  
Hameed Alsamadany ◽  
Hassan S. Al-Zahrani ◽  
El-Metwally M. Selim ◽  
Mohsen M. El-Sherbiny
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Ecological Risk ◽  
Oil Pollution ◽  
Gulf Coast ◽  
Arabian Gulf ◽  
Avicennia Marina ◽  
Potential Ecological Risk ◽  
Average Concentration ◽  
Grey Mangrove

AbstractTo assess trace element concentrations (Zn, Cu, Pb, Cr, Cd and Ni) in the mangrove swamps along the Saudi coast of the Arabian Gulf, thirteen samples of surface sediment and leaves of grey mangrove, Avicennia marina were collected and analyzed. The detected trace element contents (μg g-1) in surface sediments were in the following descending order according to their mean values; Cr (49.18) > Zn (48.48) > Cu (43.06) > Pb (26.61) > Ni (22.88) > Cd (3.21). The results showed that the average concentrations of Cd and Pb exceeded their world average concentration of shale. The geo-accumulation, potential ecological risk and toxicity response indices demonstrated that trace elements have posed a considerable ecological risk, especially Cd. The inter-relationships between physico-chemical characters and trace elements suggests that grained particles of mud represent a noteworthy character in the distribution of trace elements compared to organic materials. Moreover, the results revealed that Zn was clearly bioaccumulated in leaf tissues A. marina. Dredging, landfilling, sewage effluents and oil pollution can be the paramount sources of pollution in the area under investigation.

scholarly journals Vitamin Analysis, Trace Elements Content, and Their Extractabilities in Tetrapleura tetraptera

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Prince Oteng ◽  
John K. Otchere ◽  
Stephen Adusei ◽  
Richard Q. Mensah ◽  
Emmanuel Tei-Mensah
Keyword(s):  
Trace Elements ◽  
Vitamin A ◽  
Vitamin C ◽  
Trace Element ◽  
Trace Element Content ◽  
Beta Carotene ◽  
Flame Atomic Absorption ◽  
Significant Difference ◽  
Tetrapleura Tetraptera ◽  
Vitamin Analysis

Tetrapleura tetraptera is widely cherished in African traditional homes because of its alleged therapeutic and nutritional properties. This present study aimed at determining the levels of vitamin A, C, E, and beta-carotene and trace element (Fe, Cu, Mn, Co, Se, and Zn) concentrations and their extractabilities in the pulp, seeds, and whole fruit (mixture of pulp and seeds) of T. tetraptera. The total trace element concentration of Fe, Cu, Co, Mn, and Zn and their extractabilities (%) were determined using flame atomic absorption spectrometer (FAAS), whereas UV-VIS spectrophotometer was used to determine selenium concentration. The trace element content (mg/kg) based on dry weight in the pulp, seeds, and whole fruit was Fe (162.00 ± 7.14, 115.00 ± 12.00, and 154.00 ± 25.20, respectively), Zn (31.60 ± 4.77, 43.40 ± 5.29, and 41.50 ± 8.97, respectively), Cu (16.10 ± 4.98, 11.90 ± 8.40, and 17.20 ± 14.50, respectively), Mn (55.30 ± 2.41, 156.00 ± 10.20, and 122.00 ± 5.29, respectively), Co (38.10 ± 6.40, 21.10 ± 7.15, and 44.00 ± 14.90, respectively), and Se (1.49 ± 0.17, 2.43 ± 0.28, and 2.97 ± 0.27 μg/g, respectively). The mineral extractabilities (%) in the pulp, seeds, and whole fruit of T. tetraptera were established to be in the order Co > Zn > Fe > Cu > Se > Mn. Also, the chromatographic method (HPLC) was used to evaluate vitamin E concentration, and vitamin C and concentration of beta-carotene were calculated from the obtained concentration of vitamin A using a conversion factor by the titrimetric method. From the results of vitamin analysis, a significant difference (p<0.05) was observed among the pulp, seeds, and whole fruit for vitamin C and E. However, no significant difference (p>0.05) was perceived among these plant parts for vitamin A and beta-carotene. This study has therefore revealed that the pulp, seeds, and whole fruit of T. tetraptera contain varying concentrations of vitamins and trace elements and has given many vital insights on which part of T. tetraptera to consume, as concentrations of these nutrients differ in the discrete parts of the fruit.

Sign in / Sign up

Export Citation Format

Share Document