Properties of main phytoplankton species of the Black Sea, determining the change in their dominance in annual dynamics

2020 ◽  
pp. 82-93
Author(s):  
Sergey G. Chekhutskiy ◽  
Anna V. Lifanchuk
Keyword(s):  
Black Sea ◽  
Phosphorus Uptake ◽  
Large Cell ◽  
Early Spring ◽  
Early Summer ◽  
The Black Sea ◽  
Phytoplankton Species ◽  
Nitrogen And Phosphorus ◽  
Seasonal Thermocline ◽  
Specific Growth Rates

Using mathematical model, we tested three hypotheses of bloom regulation mechanisms for dominant phytoplankton species in the northeastern Black Sea. The model is based on the concept of intracellular regulation using the Droop equation, and values of the model constants that satisfy the conditions of domination are found. The bloom of the small-cell diatom Pseudo-nitzschia pseudodelicatissima is due to higher specific growth rates than other species in early spring. The half-saturation constants and minimum quotas for mineral nutrition elements (nitrogen and phosphorus) are also relatively high. In late spring and early summer, the bloom of coccolithophore Emiliania huxleyi is usually recorded. Prerequisites are a low half-saturation constant for nitrogen uptake and minimum quota for this nutrient. The third mechanism gains strength in the summer with the deepening of seasonal thermocline and the dominance of large-cell diatoms. It was shown that for the supremacy of large diatom Proboscia alata, it is necessary to have low half-saturation constants for the phosphorus uptake and minimum quotas for this nutrient.

scholarly journals Outdoor Cultivation of the Microalga Chlorella vulgaris in a New Photobioreactor Configuration: The Effect of Ultraviolet and Visible Radiation

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1962
Author(s):  
Alcinda P. Lopes ◽  
Francisca M. Santos ◽  
Tânia F. C. V. Silva ◽  
Vítor J. P. Vilar ◽  
José C. M. Pires
Keyword(s):  
Chlorella Vulgaris ◽  
Phosphorus Uptake ◽  
Biomass Productivity ◽  
Nitrogen And Phosphorus ◽  
Visible Radiation ◽  
Microalgal Culture ◽  
Wide Range ◽  
Ultraviolet Irradiance ◽  
Nitrogen And Phosphorus Uptake ◽  
Specific Growth Rates

Microalgae can be a future source of biomass with a wide range of applications, including its use to solve current environmental issues. One of the main variables for microalgal cultivation is the light supply: (i) its intensity that often does not present a uniform spatial distribution inside the culture; (ii) photoperiod; and (iii) spectrum. Therefore, this study aims to evaluate the growth of the microalgae Chlorella vulgaris in a tubular photobioreactor with compound parabolic collectors (CPCs) under outdoor conditions. The effect of ultraviolet and visible radiation on biomass productivity and nutrients (nitrogen and phosphorus) uptake was assessed. The maximum biomass productivity was (5 ± 1) × 10−3 g·L−1·h−1, and the specific growth rates ranged from (1.1 ± 0.3) × 10−2 to (2.0 ± 0.6) × 10−2 h−1. Regarding nutrient uptake, initial removal rates of (0.9 ± 0.4) mg N·L−1·h−1 for nitrogen and (0.17 ± 0.04) mg P·L−1·h−1 for phosphorus were reached. These values increased with visible and ultraviolet irradiance until certain values (143 WVIS·m−2 and 9 WUV·m−2 for biomass productivity; 101 WVIS·m−2 and 6 WUV·m−2 for nutrient removal) and then decreased for higher ones due to the photoinhibition phenomenon. Therefore, the application of CPCs to photobioreactors (PBRs) may be beneficial for microalgal culture in countries with higher latitude (with lower solar irradiance levels).

The problem of invaders in the Caspian Sea in the context of the findings of new zoo- and phytoplankton species from the Black Sea

2005 ◽  
Vol 32 (1) ◽  
pp. 65-74 ◽  
Author(s):  
T. A. Shiganova ◽  
E. I. Musaeva ◽  
L. A. Pautova ◽  
Yu. V. Bulgakova
Keyword(s):  
Black Sea ◽  
Caspian Sea ◽  
The Black Sea ◽  
Phytoplankton Species ◽  
The Caspian Sea

The role of mineral nutrients in regulation of phytoplankton community structure of the North-Eastern part of the Black Sea at the end of May 2019

2020 ◽  
pp. 56-65
Author(s):  
Anna V. Lifanchuk ◽  
Alexey V. Fedorov ◽  
Elvina I. Alieva
Keyword(s):  
Large Cell ◽  
The Black Sea ◽  
Species Structure ◽  
Nitrogen And Phosphorus ◽  
The North ◽  
Relative Contribution ◽  
North Eastern ◽  
Low Phosphorus ◽  
Nitrogen Concentrations

The effect of nitrogen and phosphorus additives on the species structure of the natural phytoplankton population at the end of May 2019 was studied. An increase in the concentration of nitrogen and phosphorus in seawater led to a rise in the number of coccolithophores, while the relative contribution of phosphorus was higher. The predominance of small-cell diatoms in the community was facilitated by the simultaneous addition of nitrogen and phosphorus. In contrast, the relative contribution of nitrogen was higher than that of phosphorus. An increase in nitrogen concentrations at relatively low phosphorus concentrations intensified the growth of large-cell diatoms.

Phytoplankton distribution and variation along a freshwater-marine transition zone (Kızılırmak River) in the Black Sea

2016 ◽  
Vol 45 (4) ◽  
Author(s):  
Özgür Baytut ◽  
Arif Gönülol
Keyword(s):  
Transition Zone ◽  
Black Sea ◽  
Harmful Algal Bloom ◽  
Salinity Gradient ◽  
Early Spring ◽  
The Black Sea ◽  
Algal Flora ◽  
Secchi Disc ◽  
Flora Of Turkey ◽  
Agglomerative Hierarchical Cluster Analysis

AbstractBoth phytoplankton of the Kizilirmak River/Black Sea transition zone and their interactions with nutrients were investigated between July 2007 and December 2008. A total of 447 taxa belonging to the divisions: Cyanobacteria (24), Bacillariophyta (209), Bigyra (1), Cercozoa (1), Charophyta (11), Chlorophyta (32), Cryptophyta (11), Miozoa (119), Euglenozoa (14), Haptophyta (13), Ochrophyta (10) and Protozoa Incertae Sedis (2) were identified at 5 different sites in the study area. Seventy four taxa were recognized as new records for the Algal Flora of Turkey and 41 taxa were determined as HAB (Harmful Algal Bloom) organisms.According to the hierarchical clustering and MDS analyses, surface phytoplankton were distributed along the salinity gradient from freshwater to saline waters, and the early spring samples were separated from the other samples. However, in addition to the agglomerative hierarchical cluster analysis, the samples were divided into four groups – “Fresh”, “Brackish”, “Marine” and “Early spring-Marine” – as a result of MDS analysis.The results of this study revealed that the surface phytoplankton were influenced by the salinity and the Secchi Disc depth together with the seasonal water temperature dynamics and NO

scholarly journals On Bulgarian sawflies, including a new species of Empria (Hymenoptera, Symphyta)

2019 ◽  
Vol 66 (1) ◽  
pp. 85-105 ◽  
Author(s):  
Andrew Liston ◽  
Marko Prous ◽  
Jan Macek
Keyword(s):  
New Species ◽  
Host Plant ◽  
Coastal Zone ◽  
Black Sea ◽  
Early Spring ◽  
The Black Sea ◽  
Plant Associations ◽  
North Eastern ◽  
First Time ◽  
A New Species

Thirty-nine species of sawfly (Symphyta) are recorded for the first time in Bulgaria. Most of these were collected during early spring of 2018, in the south-east of the country (Burgas and Varna Provinces). Empriaaridicola Macek & Prous, sp. nov. is described as new to science from specimens collected in several central, east and south European countries. Lectotypes are designated for Poecilosomaparvula Konow, 1892, Empriapravei Dovnar-Zapolskij, 1925 and E.pseudoklugi Dovnar-Zapolskij, 1929. Empriapravei and Sciapteryxbyzantina Benson, 1968 are at present only known in Europe from the coastal zone of the Black Sea. The new Bulgarian records of Hoplocampacantoti Chevin, 1986 and Neomessasteusloffi (Konow, 1892) represent large extensions in their recorded ranges, previously comprising respectively only northern France, and north-eastern Germany. Possible host plant associations are noted for several species, based on observations of adults.

scholarly journals Nutrients Dynamics in the Surface Waters of the Black Sea

2020 ◽  
Vol 37 (6) ◽  
Author(s):  
N. A. Orekhova
Keyword(s):  
Black Sea ◽  
Phytoplankton Bloom ◽  
Inorganic Nitrogen ◽  
Water Layer ◽  
The Black Sea ◽  
Deep Part ◽  
Nitrogen And Phosphorus ◽  
Current State ◽  
Nutrients Concentration ◽  
Dissolved Silicon

Purpose. One of the key characteristics of water quality and marine ecosystems’ sustainability is nutrients supply, which are the main factors of phytoplankton bloom. Since the mid 20th century, in the northwestern Black Sea and on its western shelf, significant changes in nutrients concentrations took place, which were manifested in increase of the inorganic nitrogen and phosphorus concentrations, and decrease of the dissolved silicon content, that in its turn, led to a strong anthropogenic eutrophication of the above-mentioned regions. The aim of the work is to assess the current state of the Black Sea based on the data on the nutrients distribution and dynamics in the surface water layer. Methods and Results. The data obtained in the cruises of R/V “Professor Vodyanitsky” in 2016–2019 were analyzed. The main regions under study included the deep part of the Black Sea, as well as the Crimean and Caucasian sectors of the economic zone of Russia. The data obtained showed significant variability in the nutrients concentration both in the coastal and open areas. Conclusions. A decrease of nutrients concentration in 2016–2019 as compared to that in 2009–2014 was noted, that can indicate a decrease in the eutrophication degree and an improvement of the Black Sea waters quality. Intra-annual variability of the nutrients concentration in the sea surface layer is observed. No pronounced features in spatial variability of the nutrients concentration in this layer were revealed. It is assumed that in the central deep part of the sea, their concentrations are conditioned mainly by the physical processes of water transfer. In addition to physical transport, the increased nutrients concentrations in the coastal areas are, probably, also related to influence of the anthropogenic factor, namely inflow of nutrients from the coastal sources or their formation resulting from the biogeochemical processes which include organic matter.

scholarly journals Estimation of seasonal and inter-annual variations of phytoplankton in the Black Sea on the base of remote sensed data procession and chlorophyll a in situ measurements

2019 ◽  
Vol 485 (1) ◽  
pp. 99-103
Author(s):  
S. V. Vostokov ◽  
L. I. Lobkovskiy ◽  
A. S. Vostokova ◽  
D. M. Solov'ev
Keyword(s):  
Black Sea ◽  
Early Spring ◽  
In Situ Measurements ◽  
The Black Sea ◽  
Annual Variations ◽  
Winter Convection ◽  
Color Scanner ◽  
Preceding Winter

The patterns of the seasonal and inter annual variability in the development of phytoplankton, including coc- colithophores, were studied in the northeastern part of the Black Sea in various seasons. The research was carried out on the base of remote sensed data provided by the Modis Aqua ocean color scanner and long-term ship observations. The results indicate that, in the coastal and open waters of the Black Sea, the development of phytoplankton reaches the highest level in the fall-winter and winter-spring seasons, i.e., in the periods of active winter convection. It was noted that there is a relationship between the level of coccolithophore development in the summer period and the minimal temperature of the sea surface layer in the preceding winter. The most active coccolithophore blooms, were observed after the coldest winters. Unusual winter and early spring coccolithophore blooms taking place in mild hydro meteorological conditions were registered in the Black Sea, on the base of satellite data and were confirmed by in situ measurements.

Assessment of riverine loads of nitrogen and phosphorus to the Dniester Estuary and the Black Sea over 2010–2019

2020 ◽  
Author(s):  
S. Medinets ◽  
N. Kovalova ◽  
V. Medinets ◽  
A. Mileva ◽  
I. Gruzova ◽  
...  
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Nitrogen And Phosphorus
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