scholarly journals Spatial distribution of picoseston in the Saratov reservoir in summer

2021 ◽  
pp. 176-190
Author(s):  
E. S. Krasnova ◽  
M. V. Umanskaya
Keyword(s):  
Spatial Distribution ◽  
Food Webs ◽  
Significant Contribution ◽  
Heterotrophic Bacteria ◽  
Total Biomass ◽  
Total Abundance ◽  
Saratov Reservoir ◽  
Autotrophic Picoplankton ◽  
Upper Volga ◽  
Planktonic Food

The structure and spatial distribution of picoseston in the Saratov reservoir in July 2011 and August 2014 are described. On average, the total abundance of cells and particles forming picoseston was 1.87±0.73×106 cells (part.)/mL; and the total biomass of picoseston was 43.8±19.4 µg C/L. During the study period, solitary heterotrophic bacteria and phototrophic picocyanobacteria prevailed in the picoseston of the Saratov reservoir, amounting to 77–100% of its total abundance and biomass. The proportion of picodetrital particles was extremely small (on average, 4.1% of the total biomass of picoseston). The high heterogeneity of picoceston distribution (Cv is 130% and 110% for abundance and biomass, respectively) was found in the Saratov reservoir during the study period. On average, the abundance and biomass of heterotrophic bacterioplaknton and picodetritus at stations of the tributary estuaries were slightly higher than in the riverbed. At the same time, the abundance of picocyanobacteria was higher, and the biomass was lower at the estuarine stations compared to the riverbed ones. The total number of bacterioplankton and autotrophic picoplankton in the Saratov reservoir in 2011 and 2014 corresponded to the mesotrophic level of productivity. Picodetrital particles, in contrast to the Upper Volga and Kama reservoirs, make no significant contribution to the planktonic food webs of the Saratov reservoir, at least during the study period.

scholarly journals Population, biomass, and production of heterotrophic bacteria in reservoirs of the Upper Volga

2019 ◽  
Vol 46 (1) ◽  
pp. 35-42
Author(s):  
A. I. Kopylov ◽  
D. B. Kosolapov ◽  
I. V. Rybakova
Keyword(s):  
Organic Carbon ◽  
Bacterial Communities ◽  
Heterotrophic Bacteria ◽  
Total Biomass ◽  
Epiphytic Bacteria ◽  
Production Rates ◽  
Bacterial Populations ◽  
Upper Volga ◽  
Water Layers ◽  
Benthic Bacteria

Populations, biomasses, and production rates of planktonic, epiphytic, and benthic bacterial communities were defined in two reservoirs of the upper Volga, and their contributions to total numbers of bacteria and productivity were estimated. Populations and production rates of heterotrophic bacteria in 1-cm3 samples of bottom sediments exceed fouling of higher aquatic plants by a factor of 101–102, and in the water layers by a factor of 103–104. In mesotrophic Rybinsk and eutrophic Ivankovskoye reservoirs, benthic bacteria account for 90.4% and 98.8% of the total biomass, and 99.5% and 95.8% of total heterotrophic bacterial products, respectively. In these reservoirs, dissolved organic carbon accounts for 9.55% and 1.19% of the biomass and 4.12% and 0.45% of production, and epiphytic bacteria account for 0.05% and 0.03% of the biomass and 0.03% and 0.02% of production. These findings suggest important roles of benthic bacterial populations in reservoirs of the upper Volga.

scholarly journals More, smaller bacteria in response to ocean's warming?

2015 ◽  
Vol 282 (1810) ◽  
pp. 20150371 ◽  
Author(s):  
Xosé Anxelu G. Morán ◽  
Laura Alonso-Sáez ◽  
Enrique Nogueira ◽  
Hugh W. Ducklow ◽  
Natalia González ◽  
...  
Keyword(s):  
Heterotrophic Bacteria ◽  
Total Biomass ◽  
Marine Food Webs ◽  
Flow Cytometric ◽  
Short Period ◽  
Major Shift ◽  
Temperature Manipulation ◽  
Atlantic Coastal ◽  
Individual Size ◽  
Interannual Scale

Heterotrophic bacteria play a major role in organic matter cycling in the ocean. Although the high abundances and relatively fast growth rates of coastal surface bacterioplankton make them suitable sentinels of global change, past analyses have largely overlooked this functional group. Here, time series analysis of a decade of monthly observations in temperate Atlantic coastal waters revealed strong seasonal patterns in the abundance, size and biomass of the ubiquitous flow-cytometric groups of low (LNA) and high nucleic acid (HNA) content bacteria. Over this relatively short period, we also found that bacterioplankton cells were significantly smaller, a trend that is consistent with the hypothesized temperature-driven decrease in body size. Although decadal cell shrinking was observed for both groups, it was only LNA cells that were strongly coherent, with ecological theories linking temperature, abundance and individual size on both the seasonal and interannual scale. We explain this finding because, relative to their HNA counterparts, marine LNA bacteria are less diverse, dominated by members of the SAR11 clade. Temperature manipulation experiments in 2012 confirmed a direct effect of warming on bacterial size. Concurrent with rising temperatures in spring, significant decadal trends of increasing standing stocks (3% per year) accompanied by decreasing mean cell size (−1% per year) suggest a major shift in community structure, with a larger contribution of LNA bacteria to total biomass. The increasing prevalence of these typically oligotrophic taxa may severely impact marine food webs and carbon fluxes by an overall decrease in the efficiency of the biological pump.

scholarly journals HUBUNGAN KEPADATAN IKAN DENGAN KONDISI LINGKUNGAN PERAIRAN ESTUARI DI KABUPATEN BANYUASIN

2017 ◽  
Vol 23 (2) ◽  
pp. 111
Author(s):  
Aroef Hukmanan Rais ◽  
Rupawan Rupawan ◽  
Herlan Herlan
Keyword(s):  
Water Temperature ◽  
Significant Contribution ◽  
Aurelia Aurita ◽  
Total Biomass ◽  
Biomass Distribution ◽  
Phytoplankton Abundance ◽  
Biomass Density ◽  
Fish Resources ◽  
Salinity Water ◽  
Distribution Of Fish

Estuari di wilayah Kabupaten Banyuasin dengan potensi biodiversitas sumber daya ikan yang tinggi, merupakan wilayah penangkapan yang potensial dan berkontribusi besar terhadap poduksi perikanan Provinsi Sumatera Selatan. Distribusi biomassa sumber daya ikan di wilayah estuari sangat dinamis dan dipengaruhi oleh parameter salinitas dan suhu perairan pada suatu lingkungan perairan. Penelitian ini bertujuan untuk mengetahui kondisi kepadatan biomassa ikan dalam hubungannya dengan kondisi lingkungan perairan di wilayah perairan estuari Kabupaten Banyuasin.Pengambilan sampel ikan dilakukan dengan percobaan penangkapan menggunakan alat tangkap trawl mini yang diopeasikan di tiga wilayah estuari yaitu Sungai Banyuasin, Sungai Musi dan Sungai Upang. Pada masing-masing wilayah estuari ditentukan sebanyak empat lokasi sampling. Frekuensi pengambilan sampel dilakukan sebanyak empat kali yaitu pada Maret, Juni, Agustus dan Oktober agar mewakili kondisi musiman.Parameter lingkungan yang dianalisa adalah salinitas, suhu perairan, kecerahan, nitrat, amoniak, total fosfat dan kelimpahan fitoplankton. Hasil penelitian menunjukkan sebanyak 87 spesies ikan telah teridentifikasi. Diperoleh nilai kepadatan biomassa 332,13 – 861,49 kg/km2 di estuari Upang, 590,51 – 2.235,04 kg/km2 di estuari Musi dan 1.296,4 - 33.714,88 kg/km2 di estuari Banyuasin. Spesies ubur-ubur (Aurelia aurita) mendominasi tangkapan pada Agustus hingga Oktober yang mencapai 77,22% dari biomassa total ikan dikarenakan lingkungan yang sesuai untuk keperluan pertumbuhannya. Kepadatan biomassa ikan berkorelasi positif dengan parameter salinitas dan kelimpahan fitoplankton, dan berkorelasi negatif terhadap parameter amoniak. Estuaries of Banyuasin district has a high biodiversity of fish resources and significant contribution to the fisheries production in the South Sumatera Province. The biomass distribution of fish in the estuary fluctuated and probably affected by by salinity and water temperature. This research aims to investigate the correlation between biomass density and environment condition in the estuary of Banyuasin Regency. Sampling was conducted through experimental fishing used a mini trawl that operated in three estuary areas, such as: Banyuasin Rivers, Musi Rivers, and Upang Rivers. Every estuary area was replicated for four sampling sites. Samples were collected during March, June, August and October. The waters parameters analyzed were salinity, water temperature, transparency, nitrate, ammonia, phosphate total, and phytoplankton. The results showed that about 87 species of fish have been identified. The biomass density was 332,13 – 861,49 kg/km2 in estuary Upang, 590,51 – 2.235,04 kg/km2 in estuary Musi and 1.296,4 - 33.714,88 kg/km2 in estuari Banyuasin. A jelly fish (Aurelia aurita) is dominated in August to October, up to 77.22% of total biomass. The biomass density of fish was positively correlated with salinity and phytoplankton abundance, whereas negatively correlated to ammoniac condition.

scholarly journals Fauna asociada a la pesquería de Arca Zebra (Mollusca Bivalvia: Arcidae) en Venezuela

2018 ◽  
Vol 47 (1) ◽  
Author(s):  
Roberto Díaz-Fermín ◽  
Vanessa Acosta-Balbás
Keyword(s):  
Community Structure ◽  
New Record ◽  
Diversity Index ◽  
Economic Viability ◽  
Total Biomass ◽  
Total Abundance ◽  
Physical Damage ◽  
Negative Effect ◽  
Fishing Resources ◽  
Pinctada Imbricata

Arca zebra, constitutes one of the fishing resources with the greatest economic impact in northeastern Venezuela, since it forms banks of commercial importance. During a period of nine months (May 2010-August2011) the community structure of the organisms from the trawling fishery carried out by the fishermen of the area was identified, quantified and described. The biomass and abundance of the different groups were estimated to perform Abundance-Biomass Comparison Curves (ABC) with the objective of determining the degree of affectation by the trawling activity. A total of3 249 organisms belonging to 130 species were grouped in five Phyla: Mollusca, Annelida, Arthropoda, Echinodermata and Chordata. The Sanders' diversity index was 122.9 with mollusks (70.87) and polychaetes (29.91) as the most diverse taxa. Mollusks had the highest abundance followed by polychaetes, crustaceans, echinoderms and ascidians. Mollusks and echinoderms made the largest contribution to total biomass. The most frequent species were: Mithraculus forceps, Phallucia nigra, Echinometra lucunter, Eunice rubra and Pinctada imbricata. The microgastropods Triphora melanura is recognized as a new record for the area and the polychaete Oenone fulgida, for Venezuela. The ABC curve showed that total abundance of organisms was above total biomass, suggesting that the fishery of Arca zebra has a negative effect on most groups of organisms, mainly on echinoderms, since many of them suffer strong physical damage at the time of extraction, therefore, there is a need to modify the trawl nets, increasing the mesh opening, butwithout endangering the economic viability of the fishery.

scholarly journals Growth, feeding and ecological roles of the mixotrophic and heterotrophic dinoflagellates in marine planktonic food webs

2010 ◽  
Vol 45 (2) ◽  
pp. 65-91 ◽  
Author(s):  
Hae Jin Jeong ◽  
Yeong Du Yoo ◽  
Jae Seong Kim ◽  
Kyeong Ah Seong ◽  
Nam Seon Kang ◽  
...  
Keyword(s):  
Food Webs ◽  
Planktonic Food ◽  
Ecological Roles

Decrease in diatom dominance at lower Si:N ratios alters plankton food webs

2020 ◽  
Vol 42 (4) ◽  
pp. 411-424
Author(s):  
Kriste Makareviciute-Fichtner ◽  
Birte Matthiessen ◽  
Heike K Lotze ◽  
Ulrich Sommer
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Phytoplankton Community ◽  
Plankton Community ◽  
Trophic Levels ◽  
Food Web Structure ◽  
Planktonic Food ◽  
Web Structure ◽  
Copepod Grazing ◽  
Important Food Source

Abstract Many coastal oceans experience not only increased loads of nutrients but also changes in the stoichiometry of nutrient supply. Excess supply of nitrogen and stable or decreased supply of silicon lower silicon to nitrogen (Si:N) ratios, which may decrease diatom proportion in phytoplankton. To examine how Si:N ratios affect plankton community composition and food web structure, we performed a mesocosm experiment where we manipulated Si:N ratios and copepod abundance in a Baltic Sea plankton community. In high Si:N treatments, diatoms dominated. Some of them were likely spared from grazing unexpectedly resulting in higher diatom biomass under high copepod grazing. With declining Si:N ratios, dinoflagellates became more abundant under low and picoplankton under high copepod grazing. This altered plankton food web structure: under high Si:N ratios, edible diatoms were directly accessible food for copepods, while under low Si:N ratios, microzooplankton and phago-mixotrophs (mixoplankton) were a more important food source for mesograzers. The response of copepods to changes in the phytoplankton community was complex and copepod density-dependent. We suggest that declining Si:N ratios favor microzoo- and mixoplankton leading to increased complexity of planktonic food webs. Consequences on higher trophic levels will, however, likely be moderated by edibility, nutritional value or toxicity of dominant phytoplankton species.

scholarly journals Picoplankton Community Composition by CARD-FISH and Flow Cytometric Techniques: A Preliminary Study in Central Adriatic Sea Water

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Anita Manti ◽  
Paola Boi ◽  
Federica Semprucci ◽  
Rosaria Cataudella ◽  
Stefano Papa
Keyword(s):  
Community Composition ◽  
Adriatic Sea ◽  
Heterotrophic Bacteria ◽  
Sea Water ◽  
Light Availability ◽  
Bacterial Biomass ◽  
Total Carbon ◽  
Autotrophic Picoplankton ◽  
Carbon Biomass ◽  
Card Fish

Data concerning picoplanktonic community composition and abundance in the Central Adriatic Sea are presented in an effort to improve the knowledge of bacterioplankton and autotrophic picoplankton and their seasonal changes. Flow cytometry analyses revealed the presence of two distinct bacteria populations: HNA and LNA cells. HNA cells showed an explicit correlation with viable and actively respiring cells. The study of viability and activity may increase our knowledge of the part that contributes really to the remineralization and bacterial biomass production. Authotrophic picoplankton abundance, especially picocyanobacteria, was strongly influenced by seasonality, indicating that light availability and water temperature are very important regulating factors. In terms of total carbon biomass, the main contribution came from heterotrophic bacteria with a lower contribution from autotrophic picoplankton. CARD-FISH evidenced, within the Eubacteria domain, the dominance of members of the phyla Alphaproteobacteria, with a strong contribution from SAR11clade, followed by Cytophaga-Flavobacterium and Gammaproteobacteria. The bacterial groups detected contributed differently depending when the sample was taken, suggesting possible seasonal patterns. This study documents for the first time picoplankton community composition in the Central Adriatic Sea using two different approaches, FCM and CARD-FISH, and could provide preliminary data for future studies.

Structure of microbial communities in phosphorus-limited estuaries along the eastern Adriatic coast

2015 ◽  
Vol 95 (8) ◽  
pp. 1565-1578 ◽  
Author(s):  
Mladen Šolić ◽  
Nada Krstulović ◽  
Danijela Šantić ◽  
Stefanija Šestanović ◽  
Marin Ordulj ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Community Structure ◽  
Bacterial Abundance ◽  
Heterotrophic Bacteria ◽  
Potential Importance ◽  
High Contribution ◽  
Total Bacterial Abundance ◽  
Autotrophic Biomass ◽  
Adriatic Coast ◽  
Heterotrophic Biomass

The structure of the microbial food web was studied in six estuary areas along the eastern Adriatic coast during March, July and October 2012. Limitation by phosphorus, not nitrogen, was a common feature for all studied estuaries. Heterotrophic bacteria and autotrophic picoplankton (APP) (particularly picoeukaryotes andSynechococcus) can reach notable abundances and biomasses, suggesting potential importance of the picoplankton community in P-limited estuarine environments. The main features of the microbial community structure in these environments included: (1) higher heterotrophic biomass in comparison to autotrophic biomass within the picoplankton community; (2) general domination of picoeukaryotes within the APP community, and increase of absolute and relative biomass of prokaryotic autotrophs (ProchlorococcusandSynechococcus) in the total APP in P-limited conditions; (3) domination ofSynechococcusoverProchlorococcusbiomass in all studied conditions, and common spatial distribution of these two groups of cyanobacteria, which was mostly determined by concentration of phosphorus; (4) relatively high contribution (about 50%) of LNA bacteria in the total bacterial abundance; and (5) relatively high contribution (about 33%) of heterotrophic pico-flagellates in the total flagellate abundance.

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