Microphytobenthos in the Hypersaline Water Bodies, the Case of Bay Sivash (Crimea): Is Salinity the Main Determinant of Species Composition?

In hypersaline water bodies, the microphytobenthos plays a very important ecosystem role and demonstrates variability along with a salinity change. Due to anthropogenic activity, the sharp salinity increase in Bay Sivash occurred after 2014. To assess the changes in the microalgae community during the bay ecosystem transformation, the study was conducted four times in 2018 and 2019. At every sampling period, the samples were taken in a salinity gradient (from 7 to 10 sites). A total of 40 species of microalgae were identified during all research, including Cyanobacteria (Cyanophyceae, 2 species), Ochrophyta (Bacillariophyceae, 35 species), Haptophyta (Prymnesiophyceae, 2 species), and Miozoa (Dinophyceae, 1 species). According to the calculated similarity indices of Jaccard and Czekanowski–Sørensen–Dice, the species composition significantly differed during sampling periods. A total of 15 species were recorded at salinities of 80–90 psu, and 10 species at higher salinities, which contribute 64% of all species found in this study. The microalgae abundance was two times more in the floating green algae mat than on the bottom. There was no significant correlation between the number of species and salinity in all sampling periods. In November 2018, a significant positive correlation between the number of species in the sample and total suspended solids (TSS) and dissolved organic matter (DOM) was revealed. A significant correlation between the cell length in different species and salinity and DOM concentration was noted. Before the onset of the salinity increase, 61 species of microalgae were found in Eastern Sivash, of which only 12 have now been recorded, 31% of the currently found species. The characteristics of the total microphytobenthos abundance also significantly changed during all studies. Many characteristics have changed in the bay: the concentration of total suspended matter and dissolved organic matter, the temperature regime, composition of zoobenthos and plankton, and oxygen concentration. Due to this, it is unlikely that only the salinity increase caused the microphytobenthos changes in the lagoon.

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DOM degradation by light and microbes along the Yukon River-coastal ocean continuum

Scientific Reports ◽

10.1038/s41598-021-89327-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Brice K. Grunert ◽

Maria Tzortziou ◽

Patrick Neale ◽

Alana Menendez ◽

Peter Hernes

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Salinity Gradient ◽

Coastal Ocean ◽

Interactive Effects ◽

The Arctic ◽

Yukon River ◽

Spring Freshet ◽

Dom Composition

AbstractThe Arctic is experiencing rapid warming, resulting in fundamental shifts in hydrologic connectivity and carbon cycling. Dissolved organic matter (DOM) is a significant component of the Arctic and global carbon cycle, and significant perturbations to DOM cycling are expected with Arctic warming. The impact of photochemical and microbial degradation, and their interactive effects, on DOM composition and remineralization have been documented in Arctic soils and rivers. However, the role of microbes, sunlight and their interactions on Arctic DOM alteration and remineralization in the coastal ocean has not been considered, particularly during the spring freshet when DOM loads are high, photoexposure can be quite limited and residence time within river networks is low. Here, we collected DOM samples along a salinity gradient in the Yukon River delta, plume and coastal ocean during peak river discharge immediately after spring freshet and explored the role of UV exposure, microbial transformations and interactive effects on DOM quantity and composition. Our results show: (1) photochemical alteration of DOM significantly shifts processing pathways of terrestrial DOM, including increasing relative humification of DOM by microbes by > 10%; (2) microbes produce humic-like material that is not optically distinguishable from terrestrial humics; and (3) size-fractionation of the microbial community indicates a size-dependent role for DOM remineralization and humification of DOM observed through modeled PARAFAC components of fluorescent DOM, either through direct or community effects. Field observations indicate apparent conservative mixing along the salinity gradient; however, changing photochemical and microbial alteration of DOM with increasing salinity indicate changing DOM composition likely due to microbial activity. Finally, our findings show potential for rapid transformation of DOM in the coastal ocean from photochemical and microbial alteration, with microbes responsible for the majority of dissolved organic matter remineralization.

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Interaction of dissolved organic matter with Hg(II) along salinity gradient in Boston Lake

Geochemistry International ◽

10.1134/s001670291412009x ◽

2014 ◽

Vol 52 (12) ◽

pp. 1072-1077 ◽

Cited By ~ 4

Author(s):

Rehemanjiang Wufuer ◽

Ying Liu ◽

Shuyong Mu ◽

Wenjuan Song ◽

Xue Yang ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Salinity Gradient

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Metal binding by dissolved organic matter in hypersaline water: a size fractionation study using different isolation method

10.22541/au.159363477.78799649 ◽

2020 ◽

Author(s):

Keli Yang ◽

Yaoling Zhang ◽

Yaping Dong ◽

Dongdong Li ◽

Wu Li

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Metal Binding ◽

Size Fractionation ◽

Isolation Method ◽

Hypersaline Water

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Effect of Dissolved Organic Matter on Agglomeration and Removal of CuO Nanoparticles by Coagulation

Processes ◽

10.3390/pr7070455 ◽

2019 ◽

Vol 7 (7) ◽

pp. 455 ◽

Cited By ~ 2

Author(s):

Rizwan Khan ◽

Muhammad Ali Inam ◽

Muhammad Akram ◽

Ahmed Uddin ◽

Sarfaraz Khan ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Industrial Applications ◽

Water Bodies ◽

Hydrodynamic Diameter ◽

Excess Charge ◽

High Concentration ◽

Potential Threat ◽

Cuo Nps ◽

Coagulation Process

Engineered nanomaterials (ENMs), such as copper oxide nanoparticles (CuO NPs), are emerging as pollutants extensively used in many commercial and industrial applications, thus raising environmental concerns due to their release into water bodies. It is, therefore, essential to remove these pollutants from water bodies in order to minimize the potential threat to the aquatic environment and human health. The objective of this study was to investigate the removal of CuO NPs from waters by the coagulation process. This study also explored the efficiency of coagulation to remove hydrophobic/hydrophilic dissolved organic matter (DOM) and turbidity with varying polyaluminum chloride (PACl) doses. According to the results, a high concentration of DOM affects both the CuO NPs zeta potential and hydrodynamic diameter, thereby decreasing the agglomeration behavior. At effective coagulation zone (ECR), high removal of CuO NPs (>95%) was observed for all studied waters (hydrophobic and hydrophilic waters), above ECR excess charge induced by coagulant restabilized particles in solution. Furthermore, waters containing hydrophobic DOM and those with high UV254nm values needed more coagulant dose than hydrophilic waters to obtain similar CuO NP removals. The primary mechanism involved in CuO NPs removal might be charge neutralization. These findings suggest that PACl is an effective coagulant in the removal of CuO NPs; however, water characteristics are an influencing factor on the removal performance of ENMs during the coagulation process.

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Dissolved organic matter concentration changes in river waters of Latvia

Proceedings of the Latvian Academy of Sciences Section B Natural Exact and Applied Sciences ◽

10.2478/v10046-011-0017-1 ◽

2011 ◽

Vol 65 (1-2) ◽

pp. 40-47

Author(s):

Māris Kļaviņš ◽

Ilga Kokorīte ◽

Valērijs Rodinovs

Keyword(s):

Land Use ◽

Organic Matter ◽

Dissolved Organic Matter ◽

Water Bodies ◽

Biological Processes ◽

River Waters ◽

Organic Matter Concentration ◽

Concentration Changes ◽

The Impact ◽

Matter Concentration

Dissolved organic matter concentration changes in river waters of Latvia Amounts of natural organic matter in surface waters reflect the character and intensity of biological processes in water bodies, human impact and depend on the physico-geographical environment and land-use in the catchments. Thus, analysis of the concentrations and loadings of organic substances to adjacent water bodies can be used to indicate environmental change and human impacts. This study revealed significant increasing trends of total organic carbon (TOC) and water colour in most of the studied Latvian rivers during the last decade. However, over longer time periods, there have been pronounced oscillations of TOC concentrations, stressing the importance of long-term changes of river discharge. On a yearly basis, there was a positive correlation between parameters of organic matter concentration and discharge in all selected rivers. The impact of discharge on concentrations of organic matter can be masked by other factors, such as changes in precipitation, biological processes, soil types and land-use.

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Diversity and Distribution of Naked Amoebae in Water Bodies of Sumy Region (Ukraine)

Vestnik Zoologii ◽

10.2478/vzoo-2019-0018 ◽

2019 ◽

Vol 53 (3) ◽

pp. 177-186 ◽

Cited By ~ 4

Author(s):

M. K. Patsyuk ◽

I. P. Onyshchuk

Keyword(s):

Organic Matter ◽

Species Composition ◽

Organic Matter Content ◽

Matter Content ◽

Water Bodies ◽

Ecological Groups ◽

Riparian Species ◽

Species Complexes ◽

Wide Range ◽

Naked Amoebae

Abstract Taxonomy of naked amoebae and specifics of their distribution in water bodies of Sumy Region are presented. Our research identified 12 species of naked amoebae of 11 morphotypes. We established their ecological groups relative to abiotic aquatic factors: euryoxidic, stenooxidic, stenobiotic and those that survive in a wide range of organic matter content. According to the species composition, swamp and riparian species complexes of naked amoebae were identified. It was found that species complexes of amoeba are influenced by such factors as temperature, concentration of dissolved oxygen and organic compounds.

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