scholarly journals Epizoon microalgae of the cultivated mollusk Мytilus galloprovincialis Lam. 1819, phytoplankton, hydrological and hydrochemical characteristics in the mussel-and-oyster farm area (Sevastopol, Black Sea)

2017 ◽  
Vol 2 (4) ◽  
pp. 67-83 ◽  
Author(s):  
L. I. Ryabushko ◽  
N. V. Pospelova ◽  
D. S. Balycheva ◽  
N. P. Kovrigina ◽  
O. A. Troshchenko ◽  
...  

In mollusk cultivation areas large amount of biomass and metabolites is accumulated. For this reason, biological monitoring in the farming areas, which includes study of microalgae as environmental quality indicators, is of considerable importance. Samples of mussels harvested from collectors at 6 m depth over the period February 2015 – March 2016 have been utilized for studying epizoon microalgae residing on mollusk shells. At the same time, sea water at depths of 0 and 6 m was sampled for determining phytoplankton and hydrochemical parameters of environment in the mussel-and-oyster farm area. Dissolved oxygen, biological oxygen demand after five days of incubation in the dark (BOD5), alkaline permanganate oxidizability, silicates, organic and inorganic forms of nitrogen and phosphorus have been quantified in the water samples using conventional methods. In the epizoon of the mussel shells, 108 taxa of microalgae of four phyla have been identified: 3 species of Сyanoprokaryota, 6 of Dinophyta, 6 of Haptophyta and 93 of Bacillariophyta. The maximum values of the species richness (26) and abundance of microalgae were observed in February (74,78·103 cells·cm-2, t = 9,7 °C) and April 2015 (62,0·103 cells·cm-2, t = 10,3 °C), as well as in January 2016 (65,1·103 cells·cm-2, t = 9,5 °C). The highest biomass was registered in August (0,272 mg·cm-2, t = 25,5 °C). The main contribution to the total abundance was made by the diatoms Tabularia fasciculata while Navicula ramosissima, and cyanobacteria were prevalent in the total biomass. In phytoplankton at the depths of 0 and 6 m, 135 taxa belonging to eight phyla have been found: 2 species of Cyanoprokaryota, 47 of Acillariophyta, 57 of Inophyta, 17 of Haptophyta, 5 of Chlorophyta, 2 of Euglenophyta, 3 of Cryptophyta and 2 of Chrysophyta. The genus Chaetoceros dominated by the number of diatoms species (18). In terms of abundance and biomass, the dinoflagellate Prorocentrum micans and haptophyte Emiliania huxleyi were dominant. The maximum abundance (370·107 cells·m-3) and biomass (7560 mg·m-3) of the phytoplankton were observed in spring and autumn. In total, 213 of microalgae taxa have been identified in the phytoplankton and mussel shell epizoon, with 30 ones being common for both. Furthermore, 26 potentially toxic species and 24 indicator species have been determined, among which 26 ones are betamesosaprobionts, the indicators of moderate level of water pollution. Thermohaline characteristics of water in the mollusk farm area did not exceed those of the long-term observations. At all horizons, the oxygen content was at the level of 93–125 % of saturation. The sea water oxidizability did not exceed the maximum permissible level established by fishery standards. The concentration of nutrients was high with a large fluctuation range, which indicates anthropogenic impact on the water area. The values of the total inorganic nitrogen-to-phosphorus and silicon-to-phosphorus ratios suggested nitrogen and silicon limitations for the microalgae community development from July to December. The mussel epizoon microalgae abundance strongly correlated with water temperature and dissolved oxygen, and a strong correlation of the biomass with inorganic phosphorus was observed, too. Moderate correlations were also found with inorganic phosphorus and organic nitrogen. For the phytoplankton, moderate correlations of abundance with hydrological and hydrochemical characteristics were identified: with nitrates in the surface layer and with temperature, dissolved oxygen, and organic nitrogen in the subsurface water layer. The phytoplankton biomass moderately correlated with the silicate concentration. The hydrological and hydrochemical structure of sea water, especially in the mollusk farming areas, affected species composition and quantitative characteristics of planktonic and benthic microalgae communities.

2013 ◽  
Vol 316-317 ◽  
pp. 395-399
Author(s):  
Gen Hai Zhu ◽  
Jian Qian ◽  
Li Hong Chen ◽  
Mao Jin ◽  
Jing Jing Liu ◽  
...  

The 30 years’ annual variations of major nutrients dissolved inorganic nitrogen(DIN) and dissolved inorganic phosphorus(DIP) in Xiangshan Bay East China Sea between 1982 and 2011 were reported. The results showed that the concentrations of nitrogen and phosphorus nutrients increased year by year, consistent with the trend of nitrogen and phosphorus consumption in our country. Inorganic nitrogen was the main pollutant, then was inorganic phosphorus in Xiangshan harbor. The annual average change of DIN ranged from 0.21 to 0.76 mg∙dm-3 while DIP ranged from 0.018 to 0.054 mg∙dm-3. And the change trend of DIN and DIP was as following: winter > autumn > summer > spring. The DIN and DIP in Xiangshan horbor exceeded the standard limits greatly, the water quality in culture areas exceeded national criteria for sea water Level IV and most water qualities were inferior Level IV.


Author(s):  
P.D. Klochenko ◽  
Z.N. Gorbunova ◽  
T.F. Shevchenko ◽  
T.V. Vitovetska

The content of inorganic nitrogen and phosphorus compounds, chloride, organic matter, and dissolved oxygen was studied in 11 ponds of the “Oleksandriya” Dendrological Park. Samples were taken in summer 2016–2018 in the cascade of ponds located in the Western, Middle, and Eastern ravines of the park. The obtained data suggest that the studied ponds are significantly polluted by inorganic and organic substances, the amount of which remains still very high. The ponds of the Western ravine are characterized by the highest content of inorganic nitrogen compounds and chloride.Thus, in particular, the concentration of ammonium in the Poterchata pond accounted for 103.00–160.00 mg N/L, in the Rusalka pond – 64.00–89.50 mg N/L, in the Vodyanyk pond – 28.00–43.00 mg N/L, whereas in the Skelny pond – 12.00–38.50 mg N/L. The concentration of nitrite in the studied ponds accounted for respectively 1.130–2.213 mg N/L, 1.538–1.950 mg N/L, 0.988–1.388 mg N/L, and 0.730–1.288 mg N/L. The concentration of nitrate was also rather high. Thus, in the Poterchata pond it was 52.00–81.25 mg N/L, in the Rusalka pond – 48.00–73.75 mg N/L, in the Vodyayk pond – 21.50–38.75 mg N/L, whereas in the Skelny pond – 14.50–27.50 mg N/L. The concentration of chloride in the studied ponds accounted for respectively 690.9–795.7 mg/L, 553.8–580.5 mg/L, 283.5–308.4 mg/L, and 274.5–287.1 mg/L. The highest concentration of inorganic phosphorus (0.470 mg/L) was observed in one of the ponds of the Middle ravine. The highest values of dichromate oxidizablity (97.0 and 81.0 mg O/L) were registered in the first two ponds of the Western ravine, which is indicative of their essential contamination by organic matter. The lowest concentration of the dissolved oxygen (3.8 mg/L) was observed in the ponds of the Middle ravine. The complex of measurements aimed at the improvement of the state of the ponds of the “Oleksandriya” Dendrological Park should be elaborated and realized. In particular, it is essential to reveal the main source of the pollution of the ponds of the Western ravine by inorganic nitrogen compounds and chloride, and also to keep them clear of pollutants.


2009 ◽  
Vol 60 (11) ◽  
pp. 1123 ◽  
Author(s):  
Jim Wallace ◽  
Lachlan Stewart ◽  
Aaron Hawdon ◽  
Rex Keen ◽  
Fazlul Karim ◽  
...  

Current estimates of sediment and nutrient loads from the Tully–Murray floodplain to the Great Barrier Reef lagoon are updated by taking explicit account of flood events. New estimates of flood discharge that include over-bank flows are combined with direct measurements of sediment and nutrient concentrations in flood waters to calculate the loads of sediment and nutrient delivered to the ocean during 13 floods that occurred between 2006 and 2008. Although absolute concentrations of sediment and nutrient were quite low, the large volume of water discharged during floods means that they make a large contribution (30–50%) to the marine load. By not accounting for flood flows correctly, previous estimates of the annual average discharge are 15% too low and annual loads of nitrogen and phosphorus are 47% and 32% too low respectively. However, because sediments may be source-limited, accounting for flood flows simply dilutes their concentration and the resulting annual average load is similar to that previously estimated. Flood waters also carry more dissolved organic nitrogen than dissolved inorganic nitrogen and this is the opposite of their concentrations in river water. Consequently, dissolved organic nitrogen loads to the ocean may be around twice those previously estimated from riverine data.


2021 ◽  
pp. 72-86
Author(s):  
Yu. Krot ◽  
◽  
D. Medovnyk ◽  
Yu. Krasiuk ◽  
D. Kudriavtseva ◽  
...  

Purpose. To study the peculiarities of relationships between the aquatic environment and the extruded feed residues in the circulating aquaculture systems intended for growing Clarias gariepinus, and changes in the concentrations of inorganic nitrogen compounds and phosphorus phosphates. Methodology. The object of study is the quality of the aquatic environment when modeling the food load in accordance with feeding standards of different age groups of Cl. gariepinus. Water quality in experimental tanks was determined by analytical methods. Findings. It was found that the intake of extruded feed residues into the aquatic environment leads to a deterioration in its quality due to an increase in the concentration of compounds of inorganic nitrogen and phosphorus of phosphates, which negatively affects the vital activity of Cl. gariepinus. Nitrification processes are activated under conditions of sufficient dissolved oxygen content in the environment. The overload of the aquatic environment with organic matter promotes the bacterial transformation processes of nitrogen and phosphorus compounds, which are characterized by the predominance of the ammonification process and the suppression of oxidative processes. Upon completion of the mineralization of the excess organic matter, the appearance of a sufficient amount of dissolved oxygen activates ammonium oxidation and intensifies nitrification process. The leading factors in the ammonification and nitrification processes in an environment saturated with organic matter include the dissolved oxygen content, which regulates the activity ratio of anaerobic amonifying and aerobic nitrifying microflora. Optimum aeration in Cl. gariepinus cultivation systems is determined not only by the direct physiological needs of fish, but also by the need to maintain a sufficient content of dissolved oxygen to ensure nitrification processes. Originality. The study investigated the effect of the food load on the quality of aquatic environment in the circulating aquaculture systems for Cl. gariepinus rearing. Practical value. The study results can be used to optimize Cl. gariepinus growing methods in circulating aquaculture systems with adjustable parameters at high stocking densities. Key words: African catfish, quality of the aquatic environment, food load, inorganic nitrogen compounds, phosphorus phosphate content, circulating adjustable systems.


2012 ◽  
Vol 60 (2) ◽  
pp. 109-115 ◽  
Author(s):  
Byanka Damian Mizerkowski ◽  
Eunice da Costa Machado ◽  
Nilva Brandini ◽  
Mariana Gallucci Nazario ◽  
Kleber Vieira Bonfim

An environmental assessment of the estuarine waters of Guaratuba bay, Paraná State, Brazil, is provided through the analysis of physical-chemical, biological and hydrographic dynamics. Twelve stations with a bi-monthly frequency (from October/2002 until August/2003) were sampled during spring and neap tides for the determination of pH, Secchi depth, CO2 saturation, dissolved oxygen, chlorophyll, suspended particulate matter and dissolved inorganic nutrients (nitrate, nitrite, ammonium, phosphate and silicate). Based on the evaluation of six parameters (chlorophyll, Secchi depth, CO2 saturation, dissolved inorganic nitrogen and phosphorus and dissolved oxygen), Guaratuba Bay shows a low to medium trophic status, i.e. from meso- to oligotrophic, and a predominant heterotrophic metabolism, meaning that respiration overcomes primary production. Horizontal stratification was observed during the rainy season, while during the dry season the system showed more homogeneous conditions. Inorganic and/or organic matter in Guaratuba Bay seem to be controlled mainly by the seasonality of precipitation and/ also by ebb and flood tidal phase variations.


Author(s):  
H. W. Harvey

A bio-assay of the nitrogen which was available to two phytoplankton species with their associated bacteria in an off-shore water is described.The concentrations found by assay (11·5 and 13μg N/1.) were similar to the concentration of total inorganic nitrogen compounds found by analysis (10μg N/1.).Of the organic nitrogen normally present in solution in sea water, an insignificant quantity appears to be available to the plant-bacteria community.


Author(s):  
M. W. Banoub ◽  
P. J. leB. Williams

A seasonal survey of particulate and dissolved organic material was made at E1 in the English Channel during 1968. The average integral mean values were: dissolved organic carbon 65 μg-at C/l (780 μg C/l); dissolved organic nitrogen 4·6 μg-at N/l (64 μg N/l); dissolved organic phosphorus 0·12 μg-at P/l (3·8 μg P/l); particulate organic carbon 190 μg C/l and particulate organic nitrogen 21 μg N/l. Dissolved organic carbon and the particulate organic carbon and nitrogen showed increases subsequent to the spring bloom; such increases were less evident in the dissolved organic nitrogen results and not apparent in those of dissolved organic phosphorus.Analyses were also made in March and June in 1969 at two other stations in the English Channel, in addition to E1. The results from the three stations were basically similar.


2011 ◽  
Vol 23 (3) ◽  
pp. 243-254 ◽  
Author(s):  
Ian Hawes ◽  
Karl Safi ◽  
Jenny Webster-Brown ◽  
Brian Sorrell ◽  
David Arscott

AbstractWe observed ice formation and water column attributes in four shallow Antarctic ponds between January and 7 April 2008. During that time ponds went from ice-free to > 80 cm thick ice, near-freshwater to hypersaline, well-lit to near darkness and temperatures fell to below zero. Here we examine shifts in biological activity that accompanied these changes. During February, freeze-concentration and ongoing photosynthesis increased dissolved oxygen concentration to up to 100 mg l-1, with a near-equivalent decrease in dissolved inorganic carbon and a pH rise. Benthic photosynthesis was responsible for 99% of estimated biological oxygen production. Net oxygen accumulation ceased in late February, pH began to fall and inorganic carbon to increase, but the pool of dissolved oxygen was depleted only slowly. Anoxia had been attained in only one pond by April and there was little accumulation of indicators of anaerobic activity. The nitrogen and phosphorus balances of the ponds were dominated by organic forms, which, like DOC and CDOM, behaved conservatively. Conversely, inorganic nitrogen and phosphorus uptake was evident throughout the study period, at a molar ratio of 16N:1P in two of three ponds, consistent with uptake into biological material. We found no coupling between N and P uptake and photosynthesis.


2018 ◽  
Author(s):  
Valentina Valdés ◽  
François Carlotti ◽  
Ruben Escribano ◽  
Katty Donoso ◽  
Marc Pagano ◽  
...  

Abstract. Zooplankton play a key role in the regeneration of nitrogen and phosphorus in the ocean through grazing and metabolism. This study investigates the role of the organic and inorganic nitrogen and phosphorus compounds released by copepods on biogeochemical processes and on the microbial community composition during the OUTPACE cruise (18 February–3 April 2015) at three long duration stations (LD). Two LD stations were located in the Melanesian Archipelago region (MA; LD A and LD B) and one in the South Pacific Gyre (SG; LD C), which represent oligotrophic and ultraoligotrophic regions respectively. At each station, microcosm onboard experiments were performed with locally sampled organisms, comprising a mix of epipelagic copepods fed with their natural food and then incubated along with wild microbial assemblages. In presence of copepods, ammonium and dissolved organic nitrogen showed a significant increase, compared to a control in two situations: in ammonium concentration (increasing rate: 0.29 μmol L−1 h−1 after 4 h of incubation) in LD C and in dissolved organic nitrogen concentration (rate: 2.13 μmol L−1 h−1 after 0.5 h of incubation) in LD A. In addition, during the three experiments, an enhanced remineralization (ammonification and nitrification) was observed when adding copepods compared to the controls. A shift in the composition of active bacterial community was observed for the experiments in LD A and LD B mainly characterized by an increase in Alteromonadales and SAR11, respectively and linked with changes in nutrient concentrations. In the experiment performed in LD C, both groups increased but at different periods of incubation, Alteromonadales between 1 and 2 h after the beginning of the experiment, and SAR 11 at the end of incubation. Finally, our experimental results in near in situ conditions, show that copepods can be a source of organic and inorganic compounds for bacterial communities, which respond to excretion pulses at different scales, depending on the initial environmental conditions and on their community composition. These processes can contribute significantly to nutrient recycling in the epipelagic ecosystem of ultra and oligotrophic oceanic regions.


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