Phytoplankton biodiversity in the two perennial lakes of Coimbatore,Tamil Nadu,India

The present study was focused to evaluate the phytoplankton biodiversity in two freshwater perennial lakes of Sulur and Ukkadam of Coimbatore District, Tamil Nadu, India. The study period was two years from March 2012 to February 2014. Results revealed that totally 50 species of phytoplankton include 14 Cyanophyceae, 19 Chlorophyceae, 14 Bacillariophyceae, and 3 Euglenophyceae were recorded from the Sulur lake and 36 species of phytoplankton comprising 9 species of Cyanophyceae, 15 species of Chlorophyceae, 10 species of Bacillariophyceae and 2 species of Euglenophyceae were noticed in Ukkadam lake during the study period. The recorded phytoplankton density was ranged between 22,380 and 80,590 cells/l in Sulur lake and 29,350 and 1,16,255 cells/l in Ukkadam lake. Thus, the present study overall dominance of phytoplankton group was Chlorophyceae followed by Cyanophyceae, Bacillariophyceae, and Euglenophyceae. The phytoplankton population was recorded maximum in Ukkadam lake when compared to Sulur lake. Hence, the study revealed that both Ukkadam and Sulur lakes possess an appreciable quantum of phytoplankton and it can be used for fish culture.     

Soil algae from acid rain impacted forest areas of the Krušné hory Mts. 1. Algal communities

The soil algal communities of forested and reforested, limed and unlimed plots were compared in the acid rain impacted Kru sné hory Mountains. The floristic composition of unlimed plots is similar to that found in acid forest soils with a naturally low pH and no effect of the acid rain on these communities can be detected. Chlorophyceae are the only group present in these soils. In limed areas with a higher soil pH, algal diversity is significantly increased while algal densities remain similar. Chlorophyceae, while still the dominant group, are accompanied in these soils by Bacillariophyceae, Xanthophyceae, Eustigmatophyceae and Cyanophyceae. Total vegetation cover and thus light hitting the soil surface seems to be most important in determining the algal biomass.     

The phytoplankton of the internal Gulf of Olbia (North-East Sardinia) between July 1992 and July 1993

Abstract

The density variations and phytoplankton structure of the internal Gulf of Olbia (north-east Sardinia) from July 1992 to July 1993 are described.

The most important class was the Bacillariophyceae, because it accounted for the maximum values and because it dominated over about one-third of the study cycle. The picoplankton was present practically all the year round with the greatest development from September to March. Prymnesiophyceae, Dinophyceae, Cyanophyceae and Euglenophyceae were found more numerously in summer and autumn 1992 than in the rest of the year, while Bacillariophyceae, Chlorophyceae and Chrysophyceae were mostly found in spring and summer 1993.

Among the 16 species that expressed the highest mean yearly density values (greater than 1×10⁴ cell I^-1), 10 were Bacillariophyceae, 2 Dinophyceae, 3 Chrysophyceae and 1 Chlorophycea. The Bacillariophyceae have also been the dominant class in floristic terms (49 taxa on 95 total), followed by the Dinophyceae (26), the Chlorophyceae (5), the Chrysophyceae (5), the Prymnesiophyceae (4), the Prasinophyceae (2), the Euglenophyceae (2) and the Cyanophyceae (2).     

Water quality and plankton periodicity in two contrasting mine lakes in Jos,Nigeria

Water quality and plankton periodicity was studied in two mine lakes near Jos in the younger granite area of Plateau State, Nigeria. The investigation was carried out for 8 months. Transparency, pH and NO₃-N were significantly higher in Lake II while DOM, alkalinity, PO ₄ ^3– -P, BOD and chloride were significantly higher in Lake I. The order of dominance in Lake I was Bacillariophyceae, Cyanophyceae, Chlorophyceae and Dinophyceae while for Lake II; Chlorophyceae, Cyanophyceae, Bacillariophyceae and Dinophyceae. In Lake I the zooplankton in order of dominance were Cladocera, Rotifera, Copepoda, and nauplii and in Lake II Cladocera, Copepoda, Rotifera and nauplii. Although both lakes would seem unproductive based on the PO ₄ ^3– -P and NO ₃ ^– -N levels, Lake I appears more productive than Lake II.     

Effects of Cu,Cd and Zn on photosynthesis of freshwater benthic algae

One hundred and eighteen algal isolates comprising seven classes were obtained from a range of sites from polluted rivers running through Cu or Zn mining regions, and from unpolluted rivers. All the isolates were tested for photosynthetic activity when exposed to Cu, Cd or Zn. The tolerance levels of Bacillariophyceae, Charophyceae, Cyanophyceae and Chlorophyceae to Cu showed significant positive correlations with Cu concentrations in the field. However the distribution of metal sensitivities of the algae from the sites with the same metal concentration was broad. Both Bacillariophyceae and Charophyceae had a number of strains whose sensitivity to Cu differed more widely in relation to Cu levels in the environment than Cyanophyceae and Chlorophyceae. Cyanophyceae were sensitive to all three metals, whether or not isolates were obtained from polluted sites, whereas Chlorophyceae tended to have high tolerance even in isolates from unpolluted sites. For Cd and Zn the correlation between tolerance levels and concentrations in the field was not so clear as for Cu. The occurrence of Cu tolerance was shown in 4 diatom species and one Charophyceae, whereas metal resistance occurred in some Chlorophyceae. Cu-tolerant isolates tended also to be Zn-tolerant in Bacillariophyceae, and Cd-resistant isolates tended also to be Zn-resistant in Chlorophyceae.     

Phytoplankton communities of North African wetland lakes: the CASSARINA Project

Seasonal variations in phytoplankton species composition (frequencies) and densities (cell numbers) in nine North African coastal lakes selected in Morocco (Merja Sidi Bou Rhaba, Zerga and Bokka), Tunisia (Chitane, Ichkeul and Korba lakes) and Egypt (Edku, Burullus and Manzala lakes) were investigated during 1998. The main aim was to provide gase-line information about overall phytoplankton diversity and how phytoplanktoncharacteristics differ between these contrasting aquatic systems.Water samples were collected at approximately three monthly intervals and phytoplankton analysis revealed marked seasonal and spatial differences in the quantitative and qualitative composition of the communities at each site. The Egyptian lakes generally had larger crops (Manzala and Burullus had mean crop densities of more than 104 cells ml^–1) but in the western North African sites only Korba and Sidi Bou Rhaba had closely comparable densities. Algae belonging to Bacillariophyceae, Chlorophyceae, Chrysophyceae, Cyanophyceae, Dinophyceae and Euglenophyceae were recorded. Taxa representative of all these algal groups occurred in two lakes (Korba and Manzala) but at the other seven sites only some of the groups were present.The Chlorophyceae was the most dominant group in lakes Burullus, Manzala, Korba and Sidi Bou Rhaba whereas Bacillariophyceae were dominant in lakes Zerga, Bokka and Edku. In Ichkeul and acidic Chitane the Dinophyceae and the Cyanophyceae were the dominant groups, respectively. The maximum percentage of Euglenophyceae occurred in Edku Lake but this group was absent in Sidi Bou Rhaba and Ichkeul. Cyanophyceans were present in significant numbers in all investigated lakes except in Ichkeul. A total of fifty-three genera were recorded, 17 of Chlorophyceae, 18 of Bacillariophyceae, 11 of Cyanophyceae, 3 of Chrysophyceae, 2 of Euglenophyceae and 2 of Dinophyceae. The maximum number of species (34) occurred in Burullus Lake and the minimum (6) in Ichkeul Lake. Only one lake (acidic Chitane) possessed species indicative of oligotrophic conditions. The Nile Delta lakes were the most species diverse sites.The phytoplankton communities of the nine North African lakes were composed entirely of cosmopolitan species but with one new species (Cyclotella choctawatcheeana) was recorded for the region. The data presented provide a contemporary account of the levels of algal diversity present in these sites at the end of the 20th century. The relevance of phytoplankton communities to assessment of lake status and future monitoring studies in the region is emphasised.     

Influence of atypical pluviosity on phytoplankton assemblages in a stretch of a large sub-tropical river (Brazil)

This study aimed to evaluate the influence of alterations in pluviosity and ecological variables on microphytoplankton (> 20 μm) structure (composition, richness, diversity, and abundance) and its biomass (chlorophyll-a), comparing different regions in a stretch of the low Iguaçu River and in some tributaries. Phytoplankton was sampled in 10 stations (5 in Iguaçu River and 5 in tributaries) during a dry period (April/2004) and an atypical rainy period (June/2004). The conductivity showed significant difference among the sampling points. Temperature, dissolved oxygen, pH, silicate, and nitrate showed significant differences between the dry and wet periods. Phytoplankton was composed of 149 taxa, and the most representative class was Chlorophyceae (71 taxa), followed by Bacillariophyceae (35 taxa), and Cyanophyceae (25 taxa). During the rainy period, stations of Iguaçu River showed higher taxa number and total density compared to the tributaries, but the values were similar in the dry period. Tributaries presented higher diversity and equitability in both periods. Except by two stations in Iguaçu River, the higher taxa number, densities and biomass occurred in the dry period, associated to low levels of suspended matter. The canonical correspondence analysis indicated the dominance of Bacillariophyceae and Chrysophyceae in the rainy period related to nitrate and suspended matter. Two other groups were observed in the dry period: one formed by Cyanophyceae, Dinophyceae, and Rhodophyceae, related to temperature and nitrite and other by Euglenophyceae and Chlorophyceae related to total phosphorus and silicate. The groups suggest adequate conditions of the physical, chemical and climatic factors to the establishment of the algae classes. Phytoplanktonic assemblages responded quickly to the environmental regional variations under strong influence of pluviosity, while in the dry period, homogeneity among stations and environmental variables was observed. The importance of climatic events is relevant in ecological studies in a temporal scale.     

Studies on the gut contents of leptestheriella maduraiensis (Conchostraca: Branchiopoda) Nayar and Nair

Studies on the food and feeding habits of Leptestheriella maduraiensis Nayar & Nair have shown that the organisms are nonselective algal and detrital filter feeders. They utilise available food in almost similar proportions as in the overlying pond water and it is found from the present studies that the phytoplankton (Bacillariophyceae, Chlorophyceae and Cyanophyceae) form the major part of the gut (48.9%), followed by detritus (38.6%), zooplankton (11.1%) and miscellaneous items (1 .4%).Formed part of a thesis approved for the degree of Ph.D. of the Madurai University, 1973.Formed part of a thesis approved for the degree of Ph.D. of the Madurai University, 1973.     

Size‐selective feeding on phytoplankton by two morpho‐groups of the small freshwater fish Amblypharyngodon mola

Two morpho‐groups (i.e. small, MGS and big, MGL) of the small freshwater fish Amblypharyngodon mola were studied for their feeding behaviour in the natural environment. Both the morpho‐groups fed on a variety of phytoplankton including Cyanophyceae, Chlorophyceae, Bacillariophyceae and Euglenophyceae. The fish had more Chlorophyceae and Bacillariophyceae in their gut than other phytoplankton. Costello's selectivity plots revealed that the MGS fed on the smaller phytoplankters (2–6 µm in size), whereas the MGL fed on both the small and large (up to 12 µm in size) phytoplankters. The differences in mouth areas between the two morpho‐groups were explained as a possible reason of size‐selective feeding and contribute to overcome gape limitation in A. mola. This is further accompanied by the uniform pore size of the gills (2 µm) in all the morpho‐groups. This study concluded that A. mola exhibits a size‐dependent feeding strategy regulated by gape limitation at the ingestion level. With ontogenetic shifts, flexibility appears to overcome such a limitation in the MGL, having a wider mouth area supported by jaw opening ability.     

First assessment of phytoplankton diversity in a Marrocan shallow reservoir (Sidi Abderrahmane)

In order to find effective measures to control a Moroccan shallow reservoir (Sidi Abderrahmane), a better understanding of phytoplankton composition, abundance, spatial and temporal distribution it is necessary. Trophic level and the stability status were assessed upon the basis of Shannon diversity index (H′), species richness (S), and evenness (J) index. Statistical tests were used to evaluate the different relationships between phytoplankton and the concentrations of several physico-chemical parameters, and the main soluble nutrients. In surveys, the samples were taken fortnightly from May 2011 to December 2012. 64 taxa belonging to seven groups of phytoplankton were identified, including Bacillariophyceae (25 taxa), Chlorophyceae (22 taxa), and Cyanophyceae (9 taxa). Aulacoseira granulata, Nitzschia palea, Scenedesmus acuminatus, and Oscillatoria sp, were the main contributors to the dissimilarity in temporal distribution. Phytoplankton population never reached a monospecificity situation. Shannon and evenness indices were between (0.0001?<?H′?<?0.15; 0.003?<?J?<?0.085) and manifested a young phytoplankton community with high multiplying power. There were significant correlations between total phytoplankton (r?=?0.015, p?<?.01) and water temperature. Significant negative correlations were observed between transparency and Cyanophyceae (r?=??0.208, p?<?.05) and between the number of species and transparency (r?=??0.206, p?<?.05), orthophosphorus (r?=??0.377, p?<?.01), and nitrates (r?=??0.301, p?<?.01). A negative correlation was found between Orthophosphorus and Chlorophyceae (r?=??0.377, p?<?.01). Similar correlations were also observed with nitrates and Chlorophyceae (r?=??0.297, p?<?.01), Silica and Bacillariophyceae (r?=?0, p?<?.01) and total phytoplankton (r?=??0.372, p?<?.07). The underwater light condition, as indicated by Secchi depth fluctuations, hydraulic process conditions (short residence time, short outflow/inflow ratio) were shown to be the limiting factors in regulating the density of phytoplankton. With reference to Palmer pollution index, test results indicated an oligotrophic or mesotrophic reservoir. The data presented provide the first contemporary account of the level of algal diversity present, the prominent environmental conditions and trophic status of Sidi Abderrahmane reservoir waters.     

Limnological investigations on the Rosetta branch of the Nile. III. Phytoplankton

SUMMARY.

• 1 Seasonal qualitative and quantitative studies of the phytoplankton of the Rosetta branch of the River Nile are reported. Most of the genera were Bacillariophyceae, with Chlorophyceae and Cyanophyceae second and third. Only two genera of Dinophyceae were present. The phytoplankton can be broadly described as eurythermal and euryhaline.
• 2 Phytoplankton tended to be more concentrated in surface waters and showed large variations from station to station, with noticeably lower values in the estuarine region except in January.
• 3 Most of the genera were recorded at all times but seasonally the highest numbers of diatoms and green algae were found in July during a period of high temperature and low discharge whereas blue-greens achieved maximum density in October.

     

Phytoplankton dynamics in a shallow,hypertrophic reservoir (Lake Arancio,Sicily)

Phytoplankton abundance and composition in the hypertrophic man-made Lake Arancio was analyzed, based on a programme of weekly sampling from May 1990 to November 1991 and supported by measurements of limnological parameters. The highest value of phytoplankton biomass (78 mg l^–1) was observed in October 1990, during a bloom of the desmid Closterium limneticum var. fallax, while the lowest (0.15 mg l^–1) was measured in April 1991. During spring, autumn and winter 1990, species of the genus Closterium dominated the community, in the sequence: C. aciculare, C. limneticum var. fallax, C. limneticum. The summer community was more diverse with the predominance of organisms belonging to Chlorophyceae (Chlamydomonas, Eudorina, Coelastrum) and Cyanophyceae (Microcystis, Anabaena). In spring 1991, there was a long clear-water phase during which small green algae (Ankyra, Oocystis) and cryptomonads dominated. Subsequently, the summer season was characterized by a clear sequence of dominants, drawn, in turns, from species belonging to: Bacillariophyceae, Dinophyceae, Cyanophyceae, Euglenophyceae. The physics of the reservoir and its depth, owing to filling/draining constraints in a summer-arid climate, appeared to play a key role in the dynamics of phytoplankton community.     

Salinity gradient and nutrients as major structuring factors of the phytoplankton communities in salt marshes

This study investigated the major environmental factors structuring, for a year, phytoplankton assemblages in the Sfax saltern (Tunisia): salinity and nutrients. A STATICO analysis based on 11 environmental variables and the abundances of 64 phytoplanktonic species was conducted. STATICO is used to analyze the stable part of the relationships between the environment and species, and then to determine how these relationships change over time. The analysis confirmed that the salinity gradient had a considerable influence on the composition of the phytoplanktonic communities. Bacillariophyceae and Dinophyceae dominated in the least salty ponds, whereas Chlorophyceae and Cyanophyceae dominated in the saltiest ponds, in accordance with the halotolerance level estimated for each species by calculating the optimum salinity and salt tolerance. Nitrogen (N) and phosphorus (P) ions could have a secondary influence on the phytoplankton distribution and its dynamics. Dinophyceae seem to be favored by high ammonium (NH₄ ⁺) concentrations, whereas diatoms seem to be favored by high orthophosphates (PO₄ ^3?) and nitrates (NO₃ ^?) values. The Chlorophyceae Dunalliela salina thrived in the saltiest ponds when the NO₃ ^? concentrations increased.     

The influence of photon flux density (PFD) on short term 14C incorporation into proteins,carbohydrates and lipids in freshwater algae

The effect of photon flux density (PFD) on the partitioning of photosynthetically fixed ¹⁴CO₂-C into major intracellular end products was investigated for three species of freshwater planktonic algae (Nitzschia palea, Monoraphidium minutum and Synechococcus elongatus belonging to three different classes. This study was designed to investigate the phenomenon of polysaccharide synthesis associated with the saturation of protein synthesis and to test if this process is common to all three phytoplankton species. Protein synthesis was saturated at low PFD in all three species of algae studied. However, fixed carbon was differentially stored, namely in lipids in Nitzschia palea (Bacillariophyceae), in polysaccharides in Monoraphidium minutum (Chlorophyceae), and in low molecular weight metabolites (LMW) in Synechococcus elongatus (Cyanophyceae). The results of this transient state study indicate that the metabolic pathways of algae can easily be controlled by different irradiance. Furthermore, it appears that the difference in the patterns of synthesis is taxonomy dependent.     

Effect of fluctuations in water level on phytoplankton development in three lakes of the Paraná river floodplain (Argentina)

The effect of fluctuations in water level on phytoplankton development (abundance, biomass, size structure, taxonomic composition, species diversity and rate of community compositional change) in three vegetated lakes of the Paraná River floodplain (27° 27′?S; 58° 55′?W) were studied. Between September 1995 and June 1996 there were two inputs of lotic water. Ordering of physical and chemical parameters (Principal Component Analysis) allowed the differentiation of two phases: I) without lotic influence (limnophase) and II) with lotic influence (potamophase). Two-hundred fifty-eight algal taxa were identified, of which Euglenophyceae showed the highest number of taxa (65% of total). Small Chlorophyceae and Cryptophyceae (C-strategists) predominated in density in both periods. During potamophase, the input of nutrients from a flood event produced an increase in algal biomass and a shift in phytoplankton composition from a Chlorophyceae (C-strategists), to a Cyanophyceae and Euglenophyceae (S-strategists), dominated comunity. Bacillariophyceae, Chrysophyceae, Dinophyceae and Xanthophyceae were best represented during limnophase. All phytoplankton attributes showed significant differences between phases (limnophase vs potamophase) but not among lakes. These results support the hypothesis that hydrology (floods) clearly exerts an overall impact on the phytoplankton community composition in lakes of the Paraná River floodplain. Hydrology effects the lake water chemistry, conditioned by the isolation time prior to a flood, the horizontal dragging and exchange of algae during floods, and the water residence time and aquatic vegetation coverage.     

Behaviour of catalase in some members of Chlorophyceae and Cyanophyceae

Summary The activation energy of catalase revealed statistically significant variations in Chlorophyceae and Cyanophyceae. The differences in two classes of algae may suggest a close catalase-chlorophyll relationship.     

Selective control of Microcystis using an amino acid – a laboratory assay

An amino acid (L-lysine) was screened against eighteen strains ofCyanophyceae, Bacillariophyceae and Chlorophyceae. OnlyMicrocystis strains (Cyanophyceae) were sensitive tolysine; other strains were not affected. Cells of sevenMicrocystis strains (10⁶ cellsmL^–1) were completely killed within 48h by lysine at concentrations between 0.6 and 5.0 mgL^–1. Two Microcystis strains wereinhibited by 92 and 98 %. Similar results were obtained when lysine malonateandlysine copper were used as algicides. Microcystis specieswere killed by lysine malonate at concentrations between 0.6 and 5 mgL^–1, and by lysine copper at concentrations between 0.5and 20 mg L^–1.     

Plankton composition and water quality in a pond of spring origin in Turkey

Phyto/zooplankton composition, chlorophyll a, and some water quality parameters were investigated in a spring-originated pond in Central Anatolia between February 2001 and January 2002. Water temperature, pH, dissolved oxygen, Secchi depth, total and calcium hardness, nitrate-nitrogen, nitrite-nitrogen, ammonia-nitrogen, total phosphorus, and soluble reactive phosphorus levels were analyzed. A total of 49 species belonging to Bacillariophyceae, Chlorophyceae, Cyanophyceae, Cryptophyceae, and Dinophyceae were identified. The highest phytoplankton abundance was found in August, whereas the lowest was determined in January. Phytoplankton abundance increased from February to August and declined in the following months. The Bacillariophyceae were dominant in the phytoplankton community. A total of 21 species of Rotifera, 2 species of Cladocera, and 1 genus of Copepoda were found. The zooplankton community was dominated by Rotifera. The highest abundance of zooplankton was recorded in July and the lowest value in November. The annual mean concentration of chlorophyll a was measured as 1.90 μg l⁻¹. In spite of these eutrophic levels (mean values of total phosphorus and nitrate-nitrogen: 0.069 mg P l⁻¹ and 0.68 mg N l⁻¹), phytoplankton cannot grow satisfactorily because of the short water retention time (0.6 day⁻¹). The shallowness of the pond together with the low phytoplankton biomass and the high concentrations of nutrients are discussed.     

Some notes about the Intermediate Disturbance Hypothesis and its effects on the phytoplankton of the middle Orinoco river

Phytoplankton behaviour in the middle reaches of the Orinoco river (middle basin) is discussed in relation to the Intermediate Disturbance Hypothesis. Seven sets of samples were taken from two channels formed below the confluence of Meta and Orinoco rivers between September 1990 and August 1991. The Orinoco river channel (ORISMA-1) had many more species than the Meta river channel (ORISMA-2). Chlorophyceae dominated both, except during the rising water period when Bacillariophyceae were dominant. The quantitative dominancy alternates among Chlorophyceae, Bacillariophyceae and Cryptophyceae in both river channels, with minima averaging 14 329 and maxima of 1038 392 cells per liter. The phytoplankton concentration of both river channels is negatively correlated with variability in suspended sediments load. The Shannon-Weaver diversity for ORISMA-1 gives higher values than those from ORISMA-2 and oscillates between 1.37 to 3.52. Disturbances due to increases of water level and high concentration of suspended sediment can be the driving force governing phytoplankton behaviour in large rivers.