surface sediments
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Separations ◽  
2022 ◽  
Vol 9 (1) ◽  
pp. 19
Author(s):  
José Gustavo Ronderos-Lara ◽  
Hugo Saldarriaga-Noreña ◽  
Mario Alfonso Murillo-Tovar ◽  
Laura Alvarez ◽  
Josefina Vergara-Sánchez ◽  
...  

This study evaluated the distribution and potential estrogenic risk of the presence of bisphenol A (BPA), 4-nonylphenol (4NP), naproxen (NPX), ibuprofen (IBU), 17-β-estradiol (E2) and 17-α-ethinylestradiol (EE2) in water and sediments of the Apatlaco river micro-basin (Morelos, Mexico). The concentration of the determined compounds ranged between <LOD to 86.40 ng·L−1 and <LOD to 3.97 ng g−1 in water and sediments, respectively. The Log Kd distribution obtained (from 1.05 to 1.91 L Kg−1) indicates that the compounds tend to be adsorbed in sediments, which is probably due to the hydrophobic interactions confirmed by the significant correlations determined mainly between the concentrations and parameters of total organic carbon (TOC), total suspended solids (TSS), biological oxygen demand (BOD5) and chemical oxygen demand (COD). Of five sites analyzed, four presented estrogenic risk due to the analyzed endocrine-disrupting compounds (EEQE2 > 1 ng·L−1).


2022 ◽  
Author(s):  
Yuewei MA ◽  
Wenmian DING ◽  
Yuepeng WANG ◽  
Ping CHEN ◽  
Hui ZHOU ◽  
...  

Hailed as "The Fourth Pole", the Mariana Trench is the deepest part of the ocean. The microbial diversity in it is extremely complicated, which might be caused by the unique environmental factors such as high salinity, low temperature, high hydrostatic pressure, and limited nutrition. Based on 4 seawater samples and 4 sediment samples obtained from the Mariana Trench, we isolated and fostered the microorganism clones with kinds of culture mediums and high-throughput culturing. By using the molecular identification methods based on PCR of 16S rDNA and ITS gene, 1266 bacterial strains in total were isolated and identified, which affiliated to 7 classes, 16 orders, 25 families and 36 genera in four phyla:Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. Strains in genera Halomonas, Pseudoaltermonas were the dominant bacteria isolated from the samples. With Mantel tests on the sample-environmental parameter matrix, the sample-environmental organic matter diversity matrix and the sample-microbial diversity matrix, we concluded that the environmental parameters and the organic matters in the condition can shape the culturable bacterial diversity in deep-sea water and surface sediments from the Mariana Trench.


2022 ◽  
pp. 1-21
Author(s):  
Dang Hoai Nhon ◽  
Nghi Duong Thanh ◽  
Ha Nguyen Manh ◽  
Luu Nguyen Thi Mai ◽  
Huong Do Thi Thu ◽  
...  

Author(s):  
K. Chaira ◽  
B. Ennaffah ◽  
F. Z. Bouthir ◽  
H. Abdelouahab ◽  
H. Rhinane

Abstract. The Sidi Moussa lagoon, (32°52′0″ N / 8° 51′05″ W) is located on the Moroccan Atlantic coast between the cities of El Jadida and Safi about 15 km South of the Jorf Lasfar industrial complex, The climate of the lagoon is classified as hot temperate. It is characterised by an oceanic influence. This study of dinoflagellate cyst mapping is the first of its kind from the Sidi Moussa lagoon. the objectives of the present survey were (i) to evaluate to the spatial variation of dinoflagellate cyst assemblages in the sediment along the Sidi Moussa lagoon (ii) to assess the densities of its cysts (iii) to compare the cyst assemblages in this study with that of other sites. The data were collected in a scientific campaign by zodiac carried out from in April 2018 by core following a sampling network of 21 stations distributed randomly in the study area. The surface layer of the sediment cores (3 cm) was sliced and kept at 4° C until analysis. The highest total cyst abundance was 194 cysts. g−1 dry sediment. The Pearson statistical test revealed a positive and significant correlation between cyst abundance and water content, organic matter and of fine sediment. Our study showed the presence of morphotypes of potentially toxic species. The cysts of these species present in the sediment of the Sidi Moussa lagoon could germinate, when environmental conditions become favorable, and in turn could inoculate the water column with the subsequent bloom formation. This study confirms the usefulness of cyst analysis in the assessment of harmful bloom risk in this area important for oyster’s culture.


2022 ◽  
Author(s):  
Raúl Tapia ◽  
Sze Ling Ho ◽  
Hui-Yu Wang ◽  
Jeroen Groeneveld ◽  
Mahyar Mohtadi

Abstract. Planktic foraminifera are widely used in palaeoceanographic and paleoclimatic studies. The accuracy of such reconstructions depends on our understanding of the organisms’ ecology. Here we report on field observations of planktic foraminiferal abundances (>150 µm) from 5 depth intervals between 0–500 m water depth at 37 sites in the eastern tropical Indian Ocean. The total planktic foraminiferal assemblage comprises 29 morphospecies; with 11 morphospecies accounting for ~90 % of the total assemblage. Both species composition and dominance in the net samples are broadly consistent with the published data from the corresponding surface sediments. The abundance and vertical distribution of planktic foraminifera are low offshore west Sumatra, and increase towards offshore south Java and the Lesser Sunda Islands (LSI). Average living depth of Trilobatus trilobus, Globigerinoides ruber, and Globigerina bulloides increases eastward, while that of Neogloboquadrina dutertrei, Pulleniatina obliquiloculata, and Globorotalia menardii remains constant. We interpret the overall zonal and vertical distribution patterns in planktic foraminiferal abundances as a response to the contrasting upper water column conditions during the southeast monsoon, i.e., oligotrophic and stratified offshore Sumatra (non-upwelling) vs. eutrophic and well-mixed offshore Java-LSI (upwelling). Overall, the inferred habitat depths of selected planktic foraminifera species show a good agreement with those from sediment trap samples and from surface sedimentss off Sumatra, but not with those from surface sediments off Java-LSI. The discrepancy might stem from the different temporal coverage of these sample types. Our findings highlight the need to consider how foraminiferal assemblages and ecology vary on shorter timescales, i.e., from “snapshots” of the water column captured by plankton net to seasonal and interannual variability as recorded in sediment traps and how these changes are transferred and preserved in deep-sea sediments.


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