Phytoplankton composition and pigment concentrations as indicators of water quality in the Rybinsk reservoir

Long-term changes in phytoplankton (1954–1981) and chlorophyll (1969–1984) and their spatial distribution in summer 1989 were studied in the Rybinsk reservoir (second largest reservoir of the Volga River, North-West Russia). Estimation of trophic status and saprobity of the reservoir was based on phytoplankton biomass and species composition and chlorophyll content. The most eutrophic waters were found to occupy the peripheral areas in littoral zone and river inflows of the reservoir, while the waters in the central part of the basin were less eutrophic. Long-term changes of the phytoplankton biomass, chlorophyll, chlorophyll/biomass-ratio and saprobity index observed in the central part of the reservoir were analyzed by statistical methods. An increase in saprobity and an inverse relationship between chlorophyll/biomass-ratio and water transparency demonstrate progressive eutrophication in the central part of the reservoir. Two distinct periods (1954–1970 and 1971–1984) could be discerned on the basis of annual mean phytoplankton biomass values. For the earlier period a relationship between biomass and climatic factors (solar radiation and wind velocity) could be established, but no such correlation could be found for the latter period. There was no significant increase in the phytoplankton biomass during the monitoring period, but a definite increase in the proportion of small-sized species of centric diatoms, cryptomonads and blue-greens. These forms are considered as r-strategists in the community, and their increase is interpreted as a sign of eutrophication.     

Phytoplankton dynamics and structure: a comparative analysis in natural and man-made water bodies of different trophic state

Previous investigations on Sicilian man made lakes suggested that physical factors, along with the specific morphology and hydrology of the water body, are important in selecting phytoplankton species. In particular, the variations of the z _mix/z _eu ratio due to the operational procedure to which reservoirs are generally subject were recognised as a trigger allowing the assemblage shift. To investigate if these variations may be considered analogous to those occurring in natural lakes as trophic state and phytoplankton biomass increase, causing a transparency decrease and a contraction of the euphotic depth, phytoplankton were collected in two natural water bodies, one mesotrophic (Lake Biviere di Cesarò) the other eutrophic (Lake Soprano), and compared with those collected in two reservoirs with analogous trophic characteristics (Lake Rosamarina, mesotrophic and Lake Arancio, eutrophic). Particular attention was paid to the dynamics of two key groups: Cyanophytes and chlorophytes. In all four water bodies, transparency mainly depended on chlorophyll level. Annual average value of phytoplankton biomass in the mesotrophic environments was below 2.0 mg l^–1, whereas in the eutrophic systems it was well above 10 mg l^–1. All water bodies showed the presence of cyanophytes (e.g. Anabaena spp., Anabaenopsis spp., Microcystis spp., Planktothrix spp.) and chlorophytes (e.g. Chlamydomonas spp., Botryococcus spp., Oocystis spp., Scenedesmus spp., Pediastrum spp.), but their relative proportions and body size dimensions were different. In particular, small colonial chlorophytes and large-colony forming cyanophytes were most common in the most eutrophic water bodies, whereas larger colonies of green algae in those with a lower trophic state. The results showed that, under the same climatic conditions, autogenic (increase of biomass, decrease in light penetration and euphotic depth) and allogenic (use of the stored waters, anticipated breaking of the thermocline, increase of the mixing depth) processes may shift the structure of phytoplankton assemblage in the same direction even though the quantity of biomass remains linked to nutrient availability.     

Phytoplankton of the Karasuk River (West Siberia) as an indicator of water quality

The authors discuss the indicator value of taxonomic structure, abundance, and biomass of phytoplankton and use of the indicators to characterize water quality by example of the Karasuk River, West Siberian Plain.     

Phytoplankton composition of the New York Bight and adjacent waters

The New York Bight possesses a diverse assemblage of phytoplanktonwhere seasonal periods of high growth are dominated by several,chain-forming diatoms and a pico-nanoplankton component Thecomposition is similar to other regions of the northeasternshelf, producing late winter-early spring and fall maxima.     

Cell wall chemical composition of Enterococcus faecalis in the viable but nonculturable state

The viable but nonculturable (VBNC) state is a survival mechanism adopted by many bacteria (including those of medical interest) when exposed to adverse environmental conditions. In this state bacteria lose the ability to grow in bacteriological media but maintain viability and pathogenicity and sometimes are able to revert to regular division upon restoration of normal growth conditions. The aim of this work was to analyze the biochemical composition of the cell wall of Enterococcus faecalis in the VBNC state in comparison with exponentially growing and stationary cells. VBNC enterococcal cells appeared as slightly elongated and were endowed with a wall more resistant to mechanical disruption than dividing cells. Analysis of the peptidoglycan chemical composition showed an increase in total cross-linking, which rose from 39% in growing cells to 48% in VBNC cells. This increase was detected in oligomers of a higher order than dimers, such as trimers (24% increase), tetramers (37% increase), pentamers (65% increase), and higher oligomers (95% increase). Changes were also observed in penicillin binding proteins (PBPs), the enzymes involved in the terminal stages of peptidoglycan assembly, with PBPs 5 and 1 being prevalent, and in autolytic enzymes, with a threefold increase in the activity of latent muramidase-1 in E. faecalis in the VBNC state. Accessory wall polymers such as teichoic acid and lipoteichoic acid proved unchanged and doubled in quantity, respectively, in VBNC cells in comparison to dividing cells. It is suggested that all these changes in the cell wall of VBNC enterococci are specific to this particular physiological state. This may provide indirect confirmation of the viability of these cells.     

Phytoplankton and Nutrients in the River Strymon,Greece

Phytoplankton species composition, biomass, diversity, nutrients and chlorophyll a were studied at monthly intervals from December 1991 to December 1992 in a selected area of the river Strymon. SRP ranged from 53 to 182 μg⁻¹ l⁻¹ and DIN from 265 to 850 μg⁻¹ I⁻¹. Nutrient values do not indicate strong anthropogenic effects. Chlorophyll α ranged from 1.0 to 35.3 μg⁻¹ I⁻¹ and followed the temporal distribution of total phytoplankton biomass. Phytoplankton biomass exhibited maxima in winter – spring and summer (6.8 g m⁻³ in December 1991, 4.8 g m⁻³ in April 1992 and 9.3 g m⁻³ in August 1992) composed mainly of diatoms, chlorphytes, cyanophytes and dinophytes. Nanoplankton was the most important component of phytoplankton biomass (69.5%) revealing increased values in winter and early spring. Phytoplankton diversity ranged from 0.8 to 3.2. The hydrological conditions in the river Strymon seem to be appropriate for the algae to reproduce themselves in the running water and so, to develop as a true potamoplankton. However, significant populations of phytoplankton must have been carried out from the Kerkini reservoir, situated at the north of the sampling station. The phytoplankton species composition and their periodicity in the river resemble those of typical, large, lowland and nutrient – rich rivers of Europe.     

Phytoplankton spring bloom in the Tagus coastal waters: hydrological and chemical conditions

Spatial variability of phytoplankton as well as hydrological and chemical conditions in the Tagus coastal waters were studied during the spring of 1994. The highly patchy distribution of phytoplankton and the community structure were related to the specific abiotic conditions prevailing in the area. Two main water masses were distinguished: a tidally mixed one alongshore Lisbon-cape Espichel and a stratified region strongly related to the Tagus plume river. The latter seems to control, to some extent, the spatial phytoplankton variability and the timing and size of the spring bloom. The highest surficial levels of nutrients, specifically PO₄ ^3–=1.00 M, NO₃ ^–=16.0 M and Si(OH)₄=14.6 M, were clearly associated with Tagus river discharges, while the lowest levels were attained offshore in the zone of maximum chlorophyll a concentrations (30 mg m^–3) reflecting the occurrence of high nutrient consumption. Furthermore, the near depletion of PO₄ ^3– indicates P limitation for phytoplankton growth. The diatom Detonula pumila (0.1×10⁶ cells l^–1) was the dominant species of phytoplankton communities in the mixed zone, alongshore Lisbon-cape Espichel, whereas, the small diatom Thalassiosira sp. (3×10⁶ cells l^–1) was blooming offshore, associated with the stratified region.     

Phytoplankton of Lake Peipsi-Pihkva: species composition, biomass and seasonal dynamics

With 33 years of phytoplankton quantitative studies carried out, a series of qualitative data with a length of over 80 years is at our disposal. About 500 algal species have been found in plankton by different researchers. In different seasons and years 35 main species (dominants and subdominants) form 68–96 % of biomass in L. Pihkva (southern, more eutrophic part) and 60–97 % in L. Peipsi (northern, less eutrophic part). L. Lämmijärv, connecting the two parts is similar to L. Pihkva in respect to phytoplankton and the trophic state. Diatoms and blue-green algae prevail in biomass, diatoms and green algae, in the species number. The oligo-mesotrophic Aulacoseira islandica (O. Müller) Sim. is characteristic of the cool period; A. granulata (Ehr.) Sim. and Stephanodiscus binderanus (Kütz.) Krieger prevail in summer and autumn, the latter being most abundant in the southern part. Gloeotrichia echinulata (J.S. Smith) P Richter and Aphanizomenon flos-aquae (L.) Ralfs dominate in summer causing water-bloom. Phytoplankton has mostly three maxima in seasonal dynamics in L. Peipsi and two in L. Pihkva. Its average biomass in spring in different years has fluctuated in the range 5.6–16 and 6–12.7 g m^–3, in summer 3.1–14.8 and 5.6–125 (10–20 in most cases); and in autumn 7–16.3 and 5.2–26 in the northern and southern parts, respectively.The dominant complex has not changed considerably since 1909; however, the distribution of dominant species in lake parts has become more even in the last decades. Periods of high biomass occurred in the first half of the 1960s and 1970s and in 1988–1994, of low biomass in 1981–1987. The first coincided, in general, with periods of low water level and high water temperature.     

Interrelations between chemical composition of water and characteristics of zooplankton in the Novosibirsk reservoir

On the basis of an analysis of the long-term data of hydrochemical and hydrobiological monitoring of the Novosibirsk reservoir, the mutual influence of the chemical composition of water and qualitative and quantitative characteristics of a zooplankton has been revealed. The influence of the hydrochemical factors on the zooplankton is related to the peculiarities of the hydrological regime of the water basin. High correlations between the quantity of zooplankton and pH values, the concentration of nitrites and nitrates, and the values of 5-day biological oxygen demand (BOD₅) are revealed. Three basic parts of the water basin, different in the level of influence of hydrological factors and intrareservoir processes on the hydrochemical and hydrobiological characteristics of the ecosystem of the reservoir, are revealed. It is shown that, as a whole, the intrareservoir processes that occurred in the reservoir improve the quality of water in many hydrochemical indicators.     

Phytoplankton of small bodies of water

Recent records of Basichlamys sacculifera (Scherff.) Skuja, Pascheriella tetras Korshik., Chrysolykos planktonicus Mack and a species of Quadricoccus Fott are given for Cheshire.     

Phytoplankton in Water Objects of the Vychegda River Basin

In 2014, for the first time in the last 55 years, phytoplankton of the water bodies of the Vychegda River Basin has been studied. The basis of plankton communities is made up of algae from Bacillariophyta, Chlorophyta, and Cyanoprokaryota divisions. In terms of quantitative indicators, leading groups with the prevalence of diatoms are identified. The range of abundance and biomass of algae is 3.92–27.82 million cells/L and 0.3–2.9 mg/L, respectively. The biomass of phytoplankton and hydrochemical indices make it possible to classify the studied water objects as second–fourth water-quality classes, with an increase in trophic status under conditions of an anthropogenic load increase.     

Phytoplankton composition and periodicity in a northeastern Quebec lake

Phytoplankton of a humic and acidic lake in north eastern Quebec was studied during three years. Composition and succession are described. The biomass is very low and no distinct seasonal maximum was observed, the periodicity of various algal groups occurring in such a way that maximal populations succeed one another and do not co-exist.Contribution number 00 from Matamek Research Station     

The influence of the chemical composition of drinking water on cuprosolvency by biofilm bacteria

AIMS: This study investigated the influence of water chemistry on copper solvation (cuprosolvency) by pure culture biofilms of heterotrophic bacteria isolated from copper plumbing. METHODS AND RESULTS: Heterotrophic bacteria isolated from copper plumbing biofilms including Acidovorax delafieldii, Flavobacterium sp., Corynebacterium sp., Pseudomonas sp. and Stenotrophomonas maltophilia were used in laboratory coupon experiments to assess their potential for cuprosolvency. Sterile copper coupons were exposed to pure cultures of bacteria to allow biofilm formation and suspended in drinking waters with different chemical compositions. Sterile coupons not exposed to bacteria were used as controls. After 5 days of incubation, copper release and biofilm accumulation was quantified. The results demonstrated that cuprosolvency in the control experiments was influenced by water pH, total organic carbon (TOC) and conductivity. Cuprosolvency in the presence of biofilms correlated with the chemical composition of the water supplies particularly pH, Langeliers Index, chloride, alkalinity, TOC and soluble phosphate concentrations. CONCLUSIONS: The results suggest water quality may influence cuprosolvency by biofilms present within copper plumbing pipes. SIGNIFICANCE AND IMPACT OF THE STUDY: The potential for water chemistry to influence cuprosolvency by biofilms may contribute to the sporadic nature of copper corrosion problems in distribution systems.     

Plankton composition and water chemistry in the mixing zone of the Selenga River with Lake Baikal

Chemical and biological components of the Selenga River waters, the largest tributary of Lake Baikal, differ significantly from the lake waters. Active transformation processes of river waters into the lake ones occur in the vast barrier-like zone in the river-sea boundary areas. This study presents results on the spatial distribution and dynamics of water chemistry as well as the quantity and diversity of phyto- and bacterioplankton at a distance of 14 km off the Selenga River mouth. The most representative tracers of river and lake waters are total amount of ions and sulphates. Principal changes of chemical and biological parameters were fixed at 1–3 km off the Selenga River mouth that was determined as a mixing zone. Intense development of phytoplankton and eukaryotic picoplankton causing the decrease of nitrate and phosphate concentrations and organic matter rise were registered in this area. Gradual replacement of river phytoplankton by the lake one, abundance reduction of microorganisms and organotrophic bacteria and percentage increase of oligotrophic and psychrotolerant bacteria occurred in the mixing zone. Replacement of PC-rich picocyanobacteria by PE-rich ones was also recorded here. At a distance of 5–7 km off the shore, nutrient concentration and plankton composition were similar to those of Lake Baikal.     

Phytoplankton Assemblages and Their Dominant Pigments in the Nervion River Estuary

In the Nervion River estuary surface samples were taken from March to September 2003 at six sites covering most of the salinity range with the aim to know the biomass and taxonomic composition of phytoplankton assemblages in the different segments. Nine groups of algae including cyanobacteria, diatoms, dinoflagellates, chlorophytes, prasinophytes, euglenophytes, chrysophytes, haptophytes, raphidophytes and cryptophytes were identified by means of a combination of pigment analysis by high-performance liquid chromatography (HPLC) and microscopic observations of live and preserved cells. Diatoms, chlorophytes and cryptophytes were the most abundant algae in terms of cells number, whereas fucoxanthin, peridinin, chlorophyll b (Chl b) and alloxanthin were the most abundant auxiliary pigments. Based on multiple regression analysis, in the outer estuary (stations 0, 1, 2 and 3) about 93% of the chlorophyll a (Chl a) could be explained by algae containing fucoxanthin and by algae containing Chl b, whereas in the rest of the estuary most of the Chl a (about 98%) was accounted for by fucoxanthin, Chl b and alloxanthin containing algae. The study period coincided with that of most active phytoplankton growth in the estuary and fucoxanthin was by far the dominant among those signature pigments. Several diatoms, chrysophytes, haptophytes and raphydophytes were responsible for fucoxanthin among identified species. Besides, dinoflagellates with a pigment pattern corresponding to chrysophytes and type 4 haptophytes were identified among fucoxanthin-bearing algae. Cryptophytes were the most abundant species among those containing alloxanthin. The maximum of Chl b registered at the seaward end in April coincided with a bloom of the prasinophytes Cymbomonas tetramitiformis, whereas the Chl b maxima in late spring and summer were accounted for by prasinophytes in the middle and outer estuary and by several species of chlorophytes in the middle and inner estuary. Other Chl b containing algae were euglenophytes and the dinoflagellate Peridinium chlorophorum. Dinoflagellates constituted generally a minor component of the phytoplankton.     

Phytoplankton composition and abundance of a central Amazonian floodplain lake

The phytoplankton community of Lake Camaleão, a smallfloodplainlake influenced by a large whitewater river, the Solimões, was monthlyinvestigated for the composition and abundance of itsphytoplankton. The seasonal influence of the floodregime on biomass, species richness and diversity, andits relation with physical and chemical factors(temperature, pH, dissolved oxygen, electricalconductivity, total seston and inorganic nutrients)was analyzed and subjected to principal componentanalysis. Diversity was variable along the seasonalcycle: relatively high values were observed at the endof the dry season supported by high nutrientconcentrations. The phytoplankton was comprised of 262 taxa,with strong dominanceof euglenoids (81%). The three sample stations did not differamong each other, except in the dry season, due todata cluster in relation to theprincipal axis (1 and 2), explaining 63% of thevariation. Biomass accumulation as a function of lakearea reduction contributed to theseresults, indicating that the phytoplankton dynamicswere hydrology-driven.     

Variation in chemical composition of the River Frome, England, from 1965 to 1972

This study covers a 7-year period from 1965 to 1972, and shows the variation in flow, water chemistry and throughput of nutrients. The annual discharge of the River Frome varied considerably from year to year, ranging from a mean value of 4.48 m³ sec⁻¹ in 1971 to one of 8.38 m³ sec⁻¹ in 1966. The mean annual nutrient losses calculated over all 7 years of study from the River Frome catchment were: Nitrate 11.4 kg ha⁻¹, phosphorus 0.49 kg ha⁻¹ and potassium 8.4 kg ha⁻¹. There has been an increase in annual throughput (in years of similar flow) of 21% in phosphate and 41% in nitrate from 1965 to 1972.     

Phytoplankton species composition and abundance in the Indian sector of the Antarctic Ocean

Summary Water samples collected in the southwestern Indian Ocean between Africa and Antarctica in March 1980 were analyzed quantitatively for phytoplankton. Diatoms dominate the phytoplankton in this region and their numbers generally increase southward with peaks of abundance in both the northern Antarctic Zone and south of the Antarctic Divergence. Average cell numbers (i.e., 6.1×10⁵ diatoms l^-1 in the Antarctic Zone) are comparable to maximum numbers previously reported for the Southern Ocean. Dinoflagellates, flagellates and monads occur in highest concentrations north of the Polar Front. Their numbers are somewhat reduced south of the Antarctic Divergence, and are lowest in the Antarctic Zone. Various diatom assemblages are characteristic of different latitudinal zones. Waters north of and in the vicinity of the Polar Front are rich in the Nitzschia, Pseudonitzschia group of species. In the Antarctic Zone, Nitzschia nana and Dactyliosolen tenuijunctus dominate. Nitzschia species of the Fragilariopsis group are most numerous at stations south of the Antarctic Divergence. Striking differences are noted between the species compositions of quantitative and net-haul samples. A few nanoplanktonic diatoms (e.g. Nitzschia nana and single cells of Chaetoceros spp.) and the weakly silicified Dactyliosolen tenuijunctus, which are dominant in the quantitative samples, are either entirely absent or present only as solitary cells in the net collections.     

Phytoplankton succession affects the composition of Polynucleobacter subtypes in humic lakes

Phytoplankton influence the composition of bacterial communities, but the taxonomic specificity of algal–bacterial interactions is unclear due to the aggregation of ecologically distinct bacterial populations by community characterization methods. Here we examine whether phytoplankton seasonal succession affects the composition of subtypes within the cosmopolitan freshwater bacterial genus Polynucleobacter. Changes in the composition of Polynucleobacter subtypes were characterized in samples collected weekly from May to August in 2003 and 2008 from three humic lakes using terminal restriction fragment length polymorphism fingerprinting of the protein‐encoding cytochrome c oxidase ccoN gene. Changes in phytoplankton population abundances explained, on average, 30% of temporal variation in the composition of Polynucleobacter subtypes and the interaction between phytoplankton and the environment explained an additional 18% of temporal variation. The effect of phytoplankton on specific Polynucleobacter subtypes was experimentally confirmed by changes in Polynucleobacter subtype composition following incubation with different phytoplankton assemblages or a no‐phytoplankton control. Phytoplankton‐associated subtypes and differentiation in substrate use among subtypes likely contribute to the effects of phytoplankton on Polynucleobacter subtype composition. Interactions between unique Polynucleobacter populations and phytoplankton highlight the ecological significance and specificity of species interactions in freshwater communities.