scholarly journals Trophic Status of the Dniester Delta Lakes in 2006-2017

2018 ◽  
Keyword(s):  
Chlorophyll A ◽  
Trophic State ◽  
Trophic Status ◽  
Physicochemical Characteristics ◽  
Nitrogen And Phosphorus ◽  
Trophic Index ◽  
Summer Time ◽  
First Time

Purpose. Assessment of trophic status of the Dniester deltaic part lakes (Bile, Svine, Tudorovo and Putrino) in 2006-2017. Methods. Determination of hydrological, hydrochemical and hydrobiological characteristics of the lakes aquatic environment has been performed using standard methodologies. Three indicators of eutrophication have been used: chlorophyll a concentration, number of bacterioplankton, trophic indices TSI and TRIX. Results. Peculiarities of physicochemical characteristics of water in the Dniester deltaic lakes have been analysed. Increased nutrients concentration has been revealed in all the lakes during past 12 years. The lowest oxygen content and oxygen saturation was established in water of the Putrino Lake, where at the same time the highest concentrations of total nitrogen and phosphorus were observed. Analysis of long-term changes of chlorophyll a and bacterioplankton has been done. Based on the lakes integrated study in summer time of 2006-2017, assessment of water trophic state has been for the first time performed for each deltaic lake. Statistical interrelations between trophic state indicators and physicochemical characteristics of the lakes have been revealed. Conclusions. It was established that the assessment of four deltaic lakes trophic status based on chlorophyll a, bacterioplankton and TSI trophic index practically coincided and evidenced increased of the lakes’ trophic status and decrease of water quality in 2012-2017 compared with previous years. All the eutrophication indicators in water of the lakes Svine, Tudorovo and Putrino during six last years corresponded to hypertrophic status, while in the Bile Lake most of eutrophication indicators were lower and corresponded to eutrophic status. Trophic index TRIX, which was developed for seawater assessment, practically always showed somewhat higher trophic status of the lakes than other indicators.

scholarly journals Study of Changes of Trophic Status of the Kuchurganske Reservoir in 2006-2018

2018 ◽  
Keyword(s):  
Chlorophyll A ◽  
Negative Correlation ◽  
Water Body ◽  
Trophic State ◽  
Trophic Status ◽  
Functional Dependence ◽  
Physicochemical Characteristics ◽  
Water Volume ◽  
Content Increase ◽  
Trophic Index

Purpose. Assessment of the trophic status of water in the Kuchurganske Reservoir in 2006-2018. Methods. Determination of hydrological, hydrochemical and hydrobiological characteristics of the water body's environment has been done using standard methodologies. Four indicators of water eutrophication have been used: chlorophyll a concentration, bacterioplankton number, trophic indices TSI and TRIX. Results. Features of physicochemical characteristics of water in the water-body have been analysed. Higher water temperature has been registered in the middle and lower parts of the water-body compared with its upper reaches. Mineral content increase in water has been found in the direction from lower to upper part; the critical for hydrobionts life decrease of oxygen concentration has been registered in the upper reaches the most often. Analysis of long-term changes in chlorophyll a and bacterioplankton has been carried out. Statistical interconnections have been established between trophic state indicators and physicochemical characteristics of the reservoir. A close positive correlation has been registered between chlorophyll а content and bacterioplankton number, which is caused by the functional dependence of bacteria on the organic matter produced by phytoplankton. It has been shown that with an increase of water volume in the reservoir the value of these indicators of trophic status went down, which was proved by close negative correlation dependence between those values and the depth of water-body. It was demonstrated for the first time that water transparency revealed close significant negative correlation with all the indices and indicators of water trophic status, which evidenced the possibility to use the transparency as a simple indicator of water trophic state as established that the Kuchurganske Reservoir’s trophic status assessment on chlorophyll a, bacterioplankton and the TSI trophic index practically coincided and evidenced the increase in trophic status of the water-body from eutrophic to hypertrophic in last 2016-2018. The reservoir’s upper reaches were characterized by higher water trophicity compared with the central and lower parts. The values of TRIX trophic index developed for marine water assessment had practically always been showing higher trophic status compared to other indicators.

scholarly journals Fluctuations of the population of Daphnia laevis Birge 1878: a six-year study in a tropical lake

2012 ◽  
Vol 72 (3) ◽  
pp. 479-487 ◽  
Author(s):  
LPM. Brandão ◽  
T. Fajardo ◽  
E. Eskinazi-Sant'Anna ◽  
S. Brito ◽  
P. Maia-Barbosa
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic State ◽  
Trophic Status ◽  
Seasonal Pattern ◽  
Ecological Research ◽  
Total Phosphorous ◽  
Long Term Ecological Research ◽  
Physical And Chemical

The fluctuation of the population of Daphnia laevis in Lake Jacaré (Middle River Doce, Minas Gerais) was monitored monthly (at one point in the limnetic region) for six years (2002-2007) as part of the Program of Long-Term Ecological Research (LTER/UFMG). The following parameters were also monitored: water temperature, pH, electrical conductivity, dissolved oxygen, chlorophyll a, total phosphorus, phosphate, total nitrogen, nitrate, nitrite, ammonia, and densities of Chaoborus and ephippia of Daphnia laevis in the sediment. A seasonal pattern was observed in the fluctuation of D. laevis, with higher densities recorded during periods of circulation (May-August). A significant correlation was found between the density of D. laevis and temperature (r = -0.47, p = 0.0001), chlorophyll-a (r = -0.32, p = 0.016) and indicators of the lake's trophic status (total phosphorus, r = 0.32, p = 0.007 and trophic state, r = 0.36, p = 0.003), as well as Chaoborus density (r = 0.43 and p = 0.002). These results indicate that changes in the physical and chemical characteristics of the water related with stratification and circulation of the lake may have a direct (temperature, total phosphorous) or an indirect (food availability, presence of predators, ephippia eclosion) influence on the fluctuation of the D. laevis population.

scholarly journals Sebaran Klorofil a, Nitrat, Fosfat dan Plankton Sebagai Indikator Kesuburan Ekosistem Mangrove Tugurejo Semarang

2018 ◽  
Vol 16 (1) ◽  
pp. 68
Author(s):  
Anik Prihatin ◽  
Prabang Setyono ◽  
Sunarto Sunarto
Keyword(s):  
Environmental Factors ◽  
Chlorophyll A ◽  
Aquatic Ecosystems ◽  
Trophic Status ◽  
Nutrient Content ◽  
Mangrove Ecosystem ◽  
Nitrate Content ◽  
Aquatic Biota ◽  
Phosphate Content ◽  
Trophic Index

ABSTRAKEkosistem mangrove merupakan suatu interaksi yang terjadi antara tanaman – tanaman mangrove dengan faktor lingkungan perairan mangrove sehingga dapat menyebabkan terjadinya kesuburan perairan dan sebagai tempat mencari makan alami bagi biota – biota perairan. Tujuan penelitian ini adalah untuk mengetahui sebaran klorofil-a, nitrat dan fosfat serta plankton pada ekosistem mangrove yang berguna untuk kelestarian hidup biota – biota perairan Mangrove. Penelitian ini dilaksanakan bulan Oktober – November 2017 di Mangrove Tapak Tugurejo Semarang. Hasil penelitian ini didapatkan kandungan klorofil a rata – rata 0,165 mg/l, kandungan nitrat rata – rata 2,188 mg/l dan kandungan fosfat rata – rata 0,045 mg/l. Kelimpahan fitoplankton ditemukan sebanyak 23 spesies dan zooplankton ditemukan sebanyak 5 spesies. Berdasarkan status indeks trofik perairan Mangrove Tapak Tugurejo Semarang termasuk dalam kategori perairan mesotrofik, yakni unsur hara dan nutrien dalam perairan mangrove kurang tersedia banyak atau sedang dan belum tercemar. Kondisi kesuburan ekosistem mangrove terpantau cukup baik bila dibandingkan dengan kandungan – kandungan unsur hara, klorofil a dan plankton yang melimpah di perairan penelitian, sehingga memungkinkan banyak terdapat kehidupan biota – bioata perairan. Kesimpulan dari penelitian ini adalah kandungan unsur hara (nitrat dan fosfat) dan klorofil a serta plankton diperairan mangrove sangat mempengaruhi kesuburan ekosistem perairan, serta plankton yang mendominasi tempat penelitian ialah dari kelas Baccilariophyceae sebanyak 21 spesies.Kata kunci: Status trofik, Plankton, Ekosistem Mangrove,  Mangrove Tapak Tugurejo Semarang.ABSTRACTMangrove ecosystem is an interaction that occurs between mangrove plants with environmental factors of mangrove waters that can cause the occurrence of water fertility and as a place of natural foraging for aquatic biota. The purpose of this research is to know the distribution of chlorophyll a, nitrate and phosphate and plankton in mangrove ecosystem which is useful for the preservation of biota life of Mangrove waters. This research was conducted in October - November 2017 at Tapak Mangrove Tugurejo Semarang. The results of this study obtained an average chlorophyll-1 content of 0.165 mg / l, an average nitrate content of 2.188 mg / l and an average phosphate content of 0.045 mg / l. Abundance of phytoplankton found as many as 23 species and zooplankton found as many as 5 species. Based on the trophic index status of Mangrove waters Tapak Tugurejo Semarang included in the category of mesotrophic waters, the nutrients and nutrients in the mangrove waters are less available or moderate and not contaminated. The condition of mangrove ecosystem fertility is observed quite well when compared with nutrient content, chlorophyll-a and plankton abundant in research waters, thus allowing many life biota - bioata waters. The conclusion of this research is the content of nutrients (nitrate and phosphate) and chlorophyll a and plankton in mangrove waters greatly affect the fertility of aquatic ecosystems, and the plankton that dominate the research site is from the Baccilariophyceae class of 21 species.Keywords : Trophic Status, Plankton, Mangrove Ecosystem, Mangrove Tapak Tugurejo SemarangCitation: Prihatin, A, Setyono, P dan Sunarto (2018). Sebaran Klorofil-a, Nitrat, Fosfat dan Plankton Sebagai Indikator Kesuburan Ekosistem di Mangrove Tapak Tugurejo Semarang. Jurnal Ilmu Lingkungan, 16(1), 68-77, doi:10.14710/jil.16.1.68-77

scholarly journals Present state of knowledge on the family Begoniaceae CA Agardh (Magnoliopsida) of Bangladesh

2018 ◽  
Vol 4 (1) ◽  
pp. 35-46
Author(s):  
PK Deb ◽  
MA Rahman
Keyword(s):  
Species Diversity ◽  
New Records ◽  
Herbarium Specimens ◽  
Field Investigations ◽  
The Family ◽  
First Time ◽  
Generic Family ◽  
Term Field

The inventory and assessment of species diversity in the mono-generic family Begoniaceae C. A. Agardh of Bangladesh were made through long term field investigations, collections, identification, survey and examination of preserved herbarium specimens and review of relevant taxonomic and floristic literature. The family is recognized to be represented in the flora of Bangladesh by 19 species under the genus Begonia L. Of these, 11 species were known to be previously recorded from the area of Bangladesh, hence additional 8 species of the present account are being reported here for the first time as new records from Bangladesh, these are: Begonia grandis Dryand. ssp. holostylla Irmsch. , B. heracleifolia Cham. and Schltdl. Cult., B. maculata Raddi Cult. B. modestiflora Kurz, B. muliensis T. T. Yu. Cult., B. scintillans Dunn, B. surculigera Kurz and B. thomsonii A. DC. An enumeration of these 19 species is prepared, and each species is cited with detailed taxonomic data. All species of the Begonia L. are herbaceous in nature and possess potential economic values, viz. 11 (52%) medicinal, 5 (24%) ornamental, 3 (14%) beverage, 1 (5%) food and 1 (5%) poisonous. Determination of status of occurrence showed that 2 (10.53%) species are common, 5 (26.32%) cultivated, 9 (47.36%) threatened and 3 (15.79%) possibly extinct in Bangladesh. Field photographs and hand drawings of recorded taxa are provided.J. Biodivers. Conserv. Bioresour. Manag. 2018, 4(1): 35-46

scholarly journals Trophic Status and Phytoplankton Limitation Conditions in a Few Bulgarian and Hungarian Danube River Wetlands

2016 ◽  
Vol 18 (2) ◽  
pp. 19-28
Author(s):  
Roumen Kalchev ◽  
Árpád Berczik ◽  
Michaela Beshkova ◽  
Mária Dinka ◽  
Hristina Kalcheva ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Trophic State ◽  
Trophic Status ◽  
Danube River ◽  
Trophic State Index ◽  
Secchi Disk ◽  
State Index

Abstract The phytoplankton limitation conditions in a few Bulgarian and Hungarian wetlands and in two more sampling sites, one for each Danube stretch, were investigated by means of trophic state index of Carlson (1977) for phytoplankton chlorophyll-a (CHL), Secchi disk depths (SD), total phosphorus (TP), and total nitrogen (TN) concentrations. Phytoplankton of both river sites was not limited by non-algal turbidity, nor was they phosphorus and nitrogen limited. In summer months the studied wetlands were predominantly nitrogen limited, while in spring and autumn limitation by non-algal turbidity prevailed.

Use of Lake Fossil Diatom Assemblages to Determine Historical Changes in Trophic Status

1989 ◽  
Vol 46 (6) ◽  
pp. 1013-1021 ◽  
Author(s):  
M. Agbeti ◽  
M. Dickman
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic Status ◽  
Eutrophic Lake ◽  
Regression Analyses ◽  
Diatom Assemblages ◽  
Trophic Index ◽  
Trophic Changes ◽  
Classification Index ◽  
Oligotrophic Condition

Based on the composition of surface sediment diatom assemblages of 30 lakes a classification index for lake trophic status was developed. The lakes were selected to represent a continuum ranging from oligotrophic to eutrophic lake types. A trophic index quotient was derived. The log diatom inferred trophic index (D.I.T.I.) was regressed against the trophic status of the lakes as determined by the log total phosphorus (r = 0.84) and log chlorophyll-a (r = 0.91). Multiple regression analyses showed significant correlations between log D.I.T.I. and the log percentage abundances of oligotrophic, mesotrophic, and eutrophic species (r = 0.89). The abundance of the trophic indicator diatom species depends not only on total phosphorus and chlorophyll-a, but possibly on the interaction of these with other factors. Using this approach, past trophic changes were inferred for oligotrophic Barbara Lake and eutrophic Chemung Lake. The study suggested that Barbara Lake had retained its present day oligotrophic condition over the last 200 yr, whereas major trophic changes have occurred in Chemung Lake.

scholarly journals Possible substellar companions in low-mass eclipsing binaries: GU Bootis and YY Geminorum

2018 ◽  
Vol 620 ◽  
pp. A72
Author(s):  
M. Wolf ◽  
H. Kučáková ◽  
P. Zasche ◽  
J. Vraštil ◽  
K. Hoňková ◽  
...  
Keyword(s):  
Precise Determination ◽  
Time Effect ◽  
Eclipsing Binaries ◽  
Physical Parameters ◽  
The Third ◽  
Low Mass ◽  
Orbital Periods ◽  
First Time

We present the next results of our long-term observational project to analyze the variations in the orbital periods of low-mass eclipsing binaries. About 70 new precise mid-eclipse times recorded with a CCD were obtained for two eclipsing binaries with short orbital periods: GU Boo (P = 0.​d49) and YY Gem (0.​d81). Observed-minus-calculated diagrams of the stars were analyzed using all reliable timings, and new parameters of the light-time effect were obtained. We derived for the first time or improved the short orbital periods of possible third bodies of 11 and 54 years for these low-mass binaries, respectively. We calculated that the minimum masses of the third components are close to 50 MJup, which corresponds to the mass of brown dwarfs. The multiplicity of these systems also plays an important role in the precise determination of their physical parameters.

scholarly journals Assessing the Effect of Tandem Phase Sentinel-3 OLCI Sensor Uncertainty on the Estimation of Potential Ocean Chlorophyll-a Trends

2020 ◽  
Vol 12 (16) ◽  
pp. 2522 ◽  
Author(s):  
Matthew L. Hammond ◽  
Stephanie A. Henson ◽  
Nicolas Lamquin ◽  
Sébastien Clerc ◽  
Craig Donlon
Keyword(s):  
Chlorophyll A ◽  
Probability Distributions ◽  
Temporal Separation ◽  
Future Studies ◽  
Northern Latitudes ◽  
Long Term Trends ◽  
Cross Calibration ◽  
First Time ◽  
Reducing Potential

The Sentinel-3 tandem project represents the first time that two ocean colour satellites have been flown in the same orbit with minimal temporal separation (~30 s), thus allowing them to have virtually identical views of the ocean. This offers an opportunity for understanding how differences in individual sensor uncertainty can affect conclusions drawn from the data. Here, we specifically focus on trend estimation. Observational chlorophyll-a uncertainty is assessed from the Sentinel-3A Ocean and Land Colour Imager (OLCI-A) and Sentinel-3B OLCI (OLCI-B) sensors using a bootstrapping approach. Realistic trends are then imposed on a synthetic chlorophyll-a time series to understand how sensor uncertainty could affect potential long-term trends in Sentinel-3 OLCI data. We find that OLCI-A and OLCI-B both show very similar trends, with the OLCI-B trend estimates tending to have a slightly wider distribution, although not statistically different from the OLCI-A distribution. The spatial pattern of trend estimates is also assessed, showing that the probability distributions of trend estimates in OLCI-A and OLCI-B are most similar in open ocean regions, and least similar in coastal regions and at high northern latitudes. This analysis shows that the two sensors should provide consistent trends between the two satellites, provided future ageing is well quantified and mitigated. The Sentinel-3 programme offers a strong baseline for estimating long-term chlorophyll-a trends by offering a series of satellites (starting with Sentinel-3A and Sentinel-3B) that use the same sensor design, reducing potential issues with cross-calibration between sensors. This analysis contributes an important understanding of the reliability of the two current Sentinel-3 OLCI sensors for future studies of climate change driven chlorophyll-a trends.

scholarly journals Microgram-Level Radiocarbon Determination of Carbonaceous Particles in Firn and Ice Samples: Pretreatment and OC/EC Separation

Radiocarbon ◽  
2013 ◽  
Vol 55 (2) ◽  
pp. 383-390 ◽  
Author(s):  
Fang Cao ◽  
Yan-Lin Zhang ◽  
Sönke Szidat ◽  
Alexander Zapf ◽  
Lukas Wacker ◽  
...  
Keyword(s):  
Ice Cores ◽  
Anthropogenic Emissions ◽  
Thermal Method ◽  
Radiation Balance ◽  
Carbonaceous Particles ◽  
Alpine Glaciers ◽  
Glacier Ice ◽  
First Time

Carbonaceous particles that comprise organic carbon (OC) and elemental carbon (EC) are of increasing interest in climate research because of their influence on the radiation balance of the Earth. The radiocarbon determination of particulate OC and EC extracted from ice cores provides a powerful tool to reconstruct the long-term natural and anthropogenic emissions of carbonaceous particles. However, this 14C-based source apportionment method has not been applied for the firn section, which is the uppermost part of Alpine glaciers with a typical thickness of up to 50 m. In contrast to glacier ice, firn samples are more easily contaminated through drilling and handling operations. In this study, an alternative decontamination method for firn samples consisting of chiselling off the outer parts instead of rinsing them was developed and verified. The obtained procedural blank of 2.8 ± 0.8 μg C for OC is a factor of 2 higher compared to the rinsing method used for ice, but still relatively low compared to the typical OC concentration in firn samples from Alpine glaciers. The EC blank of 0.3 ± 0.1 μg C is similar for both methods. For separation of OC and EC for subsequent 14C analysis, a thermal-optical method instead of the purely thermal method was applied for the first time to firn and ice samples, resulting in a reduced uncertainty of both the mass and 14C determination. OC and EC concentrations as well as their corresponding fraction of modern for firn and ice samples from Fiescherhorn and Jungfraujoch agree well with published results, validating the new method.

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