Freshwater Benthic algae

This study is focused on benthic algae (epipelic and attached algae on concrete lining stream) in Bani-Hassan stream in Holly Karbala, Iraq. The qualitative and quantitative studies of benthic algae were done by collecting 240 samples from five sites in the study area for the period from December 2012 to November 2013. Also, the environmental variables of the stream were examined in term of temporary and spatial. The results showed that the stream was alkaline, hard, oligohaline and a well aerated. The total nitrogen to the total phosphorus (TN: TP) ratio indicates nitrogen limitation. 129 species of benthic algae belonging to 57 genera were identified. Bacillariophyceae (diatoms) was the predominant taxon (95 species) followed by Chlorophyceae (16 species), Cyanophyceae (14 species), Euglenophyceae (3 species) and Pyrophyceae(one species). Some genera were found throughout the study period: and Scenedesmus. The site 3 recorded the highest total number of algae in spring 2013, and the lowest total number was at site 5 in Autumn 2013. The chlorophyll-a concentration not matched with the total number of algae.

Science popularization paper briefly introducing the diatom identification volume: Freshwater Benthic Diatoms of Central Europe (FBDCE): Over 800 Common Species Used in Ecological Assessment. M. Cantonati, M.G. Kelly & H. Lange-Bertalot (Eds.): 942 pp. Koeltz Botanical Books (ISBN 978-3-946583-06-6). English edition with updated taxonomy and added species of: Hofmann G., Werum M. & Lange-Bertalot H. 2013. Diatomeen im Süßwasser-Benthos von Mitteleuropa. Bestimmungsflora Kieselalgen für die ökologische Praxis. Über 700 der häufigsten Arten und ihre Ökologie. Lange-Bertalot, H. (Ed.): 908 pp. 2. korrigierte Aufl. Koeltz Botanical Books.
The principal goal of this volume is to provide an effective tool for diatom identification in applied ecology (diatom-based assessments and monitoring, environmental sciences etc.).

Cyanophytes were sampled in two surveys, summer 1993 and 1995, in order to compare the algal flora of 19 small springs located in the upper part of the River Sarca catchment (Northern Italy). Measurements of the main physico-chemical variables of the spring water were also carried out. The springs differ largely in altitude (from 1073 to 2130 m a.s.l.), lithology of the aquifer (calcareous/dolomitic mountains in the Brenta and igneous intrusive rocks in the Adamello region), discharge (from less than 1 to 137 l s-1), substrate particle size and exposure. Cyanophytes were present in all the rheocrenes and lacking in the helocrenes. Up to 41 cyanophyte species were observed. The genera Chamaesiphon, Homoeothrix and Phormidium were most frequent and rich in species, with a majority of epilithic taxa occuring mainly in oligotrophic fast flowing mountain streams. Sample grouping as obtained by numerical analysis (TWINSPAN, CANOCO) was mainly explained by lithology and conductivity (separation of siliceous from calcareous substrate). Other variables pointed out by the Canonical Correspondence Analysis were the degree of shading and altitude. Differences among springs are marked, as can be argued from the relation between the high total number of species found (41) and the low diversity (on the average six species) of the single sites. Rare species were mainly found in springs warranting low flow variability at the site of emergence.

The aim of this study was a combined and multifaceted characterization (morphological, molecular, lipid, pigment, and ecological data) of a Lemanea (freshwater red alga) population from the south–eastern Alps, exploring its adaptive strategies to the montane habitat, (turbulent, very–cold glacial stream with extremely low–conductivity). Although the thalli were small (only up to 1 cm), the morphology was within the current circumscription of Lemanea fluviatilis. The molecular data placed this population within a clade of specimens identified as L. fluviatilis and L. fucina. This L. fluviatilis population was determined to possess lipid classes, especially phosphatidylcholine and monogalactosyldiacylglycerol with high unsaturation index (UI) and long acyl chains, which are typical adaptations for maintaining adequate membrane fluidity and consequently all the metabolic processes associated to the plasma membrane. The carotenoids profile revealed that, besides α /β– carotene, there are significant amounts of zeaxanthin and lutein. This study further demonstrated that red algae are a rich source of important food web w–3 fatty acids and may play an important role in the diets of grazers. L. fluviatilis is reported from one of the highest elevations (2,170 m a.s.l.) known for the genus Lemanea and this species. This study confirms the presence of L. fluviatilis in a cold, unpolluted, turbulent stream and this type of stream may be its preferred habitat.

— Algae are gaining broad consideration as a substitute renewable source of biomass for the manufacture of bioethanol, due to this reason categorized under the " third generation biofuels " .İn this work, GC-MS analysis and FTIR has been done of bio-oil obtained from fast pyrolysis of Freshwater Algae(Spirogyra) in this paper we have shown a simple process of converting biomass of fresh water algae to bio-oil through pyrolysis and explained it with the help of graphs and tables. Pyrolysis is a thermal process for converting various biomasses , residues and wastes to produce high-energy-density fuels (bio-oil, biochar). The bio-oil was obtained in two step pyrolysis in which temperature of the system kept 25ºC and then increased up to 650ºC time by time. After pyrolysis these fractions were analyzed by gas chromatography/mass spectrometry (GC-MS) and FTIR which show different peaks and data of different compounds and functional groups present in this bio-oil

this article is about all Ultimate Guide to Marimo Moss Balls. In this article talks all about keeping, cultivating, carrying and tips of marimo moss balls in the freshwater tank.  Please visit our site aquascaper.org for more information about aquarium moss plants

Saber A.A., El-Tablawy N.H., El-Refaey A.A., Saber H., Singh P., Janse van Vuuren S., Cantonati M. 2022. Cyanoprokaryotes and algae: Classification and habitats. Chapter 1 In: Handbook of Algal Biofuels, M. El-sheekh & A. Abomohra (Eds). Elsevier. 38 pp. DOI: 10.1016/B978-0-12-823764-9.00024-8

On the basis of LM and SEM observations as well as of environmental data, three species of the predominantly-acidophilous diatom genus Eunotia (E. cisalpina, E. fallacoides, E. insubrica) are described as new to science, and characterized from the ecological point of view. The three new species were not distinguished from other similar ones in the past but can be identified at the LM by careful observation of diacritical characters such as valve outline (in particular the shape of the endings), dimensions, and stria density. One of the three new species (E. insubrica) presents a very peculiar ultrastructural feature, i.e. well-developed pseudoseptum-like structures at the apices. The three new species were pointed out by detailed analyses of materials sampled in the south-eastern Alps. It is put forward that diatom investigations adopting high-resolution taxonomy are particularly opportune in habitats such as those colonized by the three new species. The three new species were found...

Last year (2007) in Berlin the 21. Deutschsprachiger Diatomologen  Treffen became at the same time the 1st Central European Diatom Meeting. This change was underlined by an evident increase
in the number of participants. This trend continued with the second edition of the congress: The 2nd Central European Diatom Meeting in Trento. This was somewhat unexpected since this year (2008)
also the International Diatom Symposium will take place in a few months (07-13/09/2008) in Dubrovnik, Croatia, and several delegates announced that they would not be able to attend both meetings. In spite of this, as can be seen in Fig. 1, about hundred delegates registered for the Congress. It is therefore with satisfaction that we have the possibility to observe that their nationalities are very diverse, with an important contribution from non-German speaking countries
(Italy – “location effect” -, Czech Republic, Russia). We feel very honoured in acknowledging that some participants made long journeys to join our Congress, coming e.g. from Scotland, the eastern part of Russia, Israel, and Canada! Not surprisingly most of the participants work in Universities, but a significant share carries out its diatom investigations in other research institutions (e.g. Research Councils), and in Museums and Botanical Gardens (Fig. 2). This last observation is of special interest for us, since this year the Congress is organized in a Museum. In such Institutions, fundamental research (in particular
biodiversity documentation), collections, and educational issues and popularization are topics of prominent importance.
The topics covered by the contributions of the participants are diverse, but could be grouped into the categories shown in Fig. 3. These give an idea of ongoing diatom research in Central Europe. Not surprisingly biodiversity remains an important topic. Less obvious and – in our opinion encouraging – is the attention still given to taxonomy, a discipline which has difficulties in being acknowledged as a fundamental tool of ecological and applied research by administrators and decision makers.
In thanking the participants for coming to Trento and contributing to the Congress, we are happy that the Trentino Nature & Science Museum of Trento, a town that is not German speaking but that has always been a gate for those coming from Italy and approaching the German-speaking
area, can contribute to the continuation of the Central European Diatom Meetings, formerly Deutschsprachige Diatomologen Treffen.

Para facilitar y homogeneizar el tratamiento y la interpretación de la información generada en las redes de control biológico se presenta una colección de fichas descriptivas de los organismos fitobentónicos que incluyen: nombre científico, común, sinónimo, propiedades, descripción, ecología, ruta taxonómica e índices y métricas, foto o ilustración incluyendo la propiedad y el autor. Esta guía ha sido elaborada por la Dirección General del Agua y forma parte de una colección de cinco tomos.

The diatom Didymosphenia geminata (Lyngbye) M.Schmidt has been commonly considered a taxon restricted to pristine habitats in mountainous areas of circumboreal regions. Recent studies show that it has a broader distribution and ecological amplitude. This shift seems to have occurred recently, as it now forms large growths in rivers within its native geographical area (North America, Europe) but also mass developments have recently appeared in New Zealand, where it is considered an aggressive invasive species with dramatic ecological and economic impacts. This nuisance organism grows attached in streambeds and may impact freshwater fish and aquatic plants and insects, causing severe disturbance in food webs. This paper investigates the historic and current biogeographic range of this invasive species (and varieties) based on 1000 citations collected mainly from the scientific literature. The locations where this diatom has appeared, including both fossil and recent records, are presented in world distribution maps. Our results confirm that the native range of D. geminata is almost restricted to the Holarctic region, though its distribution area is broader than usually reported in the literature. The ecological profile of this alga, along with its nuisance effects, is also discussed. Excessive growths do not only appear in areas where this species is presumably exotic. Contrarily to general statement, reports of mass developments of D. geminata date back to the 19th century. World references to D. geminata have increased exponentially during the last decades; however; with respect to the whole diatom literature during the XIX and XX centuries, the relative frequency of citations has decreased progressively.

A new species, Pleurosigma lange-bertalotii sp. nov., is studied with light and scanning electron microscopy and described from Western Ghats, South India. The new species possesses transverse striae pattern on the external valve surface, but internal valve views show oblique striae patterns. At present the
species is assigned to the genus Pleurosigma due to the presence of oblique striation. The oblique striae pattern is continuous internally from the central nodule to the apices, and this helps to differentiate the new species from P. obscurum. The new taxon is observed only from a forested, low electrolytic stream from South Western Ghats, South India. Recent studies on diatoms suggest that the Indian sub continent is a major
geographic zone for many new diatoms, contributing to our understanding of the evolution of diatoms of this biogeographic region.

A factorial experiment was carried out in order to assess the effects of four treatment steps in diatom processing techniques (the quantity of hydrogen peroxide added to the sample, the time allowed to the digestion reaction, the use of centrifugation and the method used to settle the frustules onto the coverslip) on different aspects of the quality of the resulting microscopic slide: the concentration of organic and inorganic matter, the density, randomness and homogeneity of the frustule distribution in the slide, and the abundance of broken frustules and girdle views. The results show no significant effects of any of the experimental treatments on the proportion of broken frustules in the samples. No significant effects were related to the duration of the oxidation reaction in any of the aspects evaluated in the quality of the slides. A sample:hydrogen peroxide ratio of 1:1 for a 6-h oxidizing reaction can be used to optimize the protocol. Despite being more time consuming, the use of successive decantations instead of centrifuging is more appropriate to achieve better results. Slide quality can also be improved by leaving the coverslips to dry at room temperature in order to improve the distribution of frustules.

The biodiversity of algal communities and environmental conditions were investigated in the springs of Mt. Konjuh. The assemblages of 20 springs emerging from different lithologies (limestones and ophiolites, respectively) comprised 234 algal taxa. Diatoms and cyanobacteria were the most species-rich groups. The most common alkaliphilic, circumneutral, and eutraphentic diatoms were represented by the genera Gomphonema, Nitzschia, Navicula, Cymbella, and Achnanthidium, and by the cyanobacterial genus Phormidium. Hierarchical clustering and SIMPROF analysis based on relative algal abundance clustered springs into six groups, separating them mainly according to spring type and lithology. Indicator species for groups and springs on different litholog-ical substrata were singled out, revealing 33 taxa with preferences for ophiolites, and 20 taxa with preferences for carbonates. The values of the Shannon-Wiener diversity index were moderately high per spring location, and similar for the two groups of springs on different lithologies. A higher similarity in species composition was noted between springs on ophiolites and limestones than between springs on ophiolites and other types of siliceous sub-strata. The present study suggests that algal assemblages in springs emerging from ophiolites, even those made up by a preponderance of silicates, should be analyzed separately from those related to springs on other siliceous substrata. The results obtained showed that most of the springs studied are affected by anthropogenic impacts and morphological alterations leading to the dominance of highly competitive meso-and eutraphentic algal species, thus emphasizing the importance of further investigation and conservation of these habitats.

The former Synedra rumpens complex has long puzzled diatom taxonomists. In the nineteenth century, many infraspecific taxa were described as varieties or forms of S. rumpens. In the present study, type material of Synedra rumpens and several infraspecific taxa such as S. rumpens var. fragilarioides and S. familiaris f. parva and f. major was investigated using LM and SEM observations. For comparison, the original material of several other relevant diatom taxa (such as Fragilaria perdelicatissima, F. spinaspeciosa, Synedra campyla, S. vaucheriae var. distans) was also analysed. The results based on these comparisons show that all infraspecific taxa should be split from Fragilaria rumpens. Fragilaria campyla is a new combination within the genus Fragilaria with F. parva and S. (rumpens var.?) familiaris f. major as synonyms. Fragilaria scotica is likewise a new combination in Fragilaria. Fragilaria metcalfeana is proposed as new name for Synedra familiaris var. neogena. The analysis of F. distans and F. fragilarioides confirmed their conspecificity, with F. fragilarioides having priority as name. Finally, two new species, F. pseudofamiliaris Van de Vijver, T.M.Schuster, Kusber et D.M.Williams sp. nov. and F. bahlsiana Van de Vijver, C.E.Wetzel et Ector sp. nov. are described. Using an analysis of the associated diatom flora, the ecological preferences of each taxon are briefly discussed.

The Water Framework Directive (WFD) requires that the European Union countries determine the biological state of their waters with respect to sites of high quality. Despite bioindicators have been widely applied in running waters and deep lakes throughout all Europe, little is known about their applicability in shallow lakes. In this context, the objective of this work is to check the effectiveness of epiphytic diatoms as indicators of the trophic state in six shallow lakes of León Province (NW Spain). Epiphyton was sampled from helophyte stems in six shallow lakes covering different ecological conditions. A significant correlation was found between the total nitrogen concentration and the diatom indices SPI (Specific Polluosensitivity Index) and BDI (Biological Diatom Index), this correlation being lower with respect to the total phosphorus concentration. The classification of the lakes according to the trophic and saprobic levels based on diatoms corresponds to that obtained from the analysis of the limnological and chemical parameters of the studied systems. Despite the use of these indices has been traditionally limited to rivers and channels, our results show the effectiveness of epiphytic diatoms as biological indicators of the quality of water in Mediterranean shallow lakes and the applicability of common diatom indices for biomonitoring purposes in these aquatic ecosystems.

This opinion paper introduces a special series of articles dedicated to freshwater benthic algae and their use in assessment andmonitoring. This special series was inspired by talks presented at the 9th International Congress on the Use of Algae for Monitoring Rivers and Comparable Habitats (Trento, Italy, 2015), the latest of a series of
meetings started in 1991. In this paper, we will first provide a brief overview of phytobenthos methods in Europe. Then, we will turn towards
the ‘dark side’ of phytobenthos and describe four particular problems for phytobenthos assessment in the European Union: (1) over-reliance on a single group of algae (mostly diatoms) to the exclusion of other
groups; (2) relatively low adoption of benthic algae for ecological assessments in lakes; (3) absence ofmeasures of phytobenthos abundance; (4) approaches used to define boundaries between ecological classes. Following this, we evaluate the strengths and limitations of current phytobenthos assessment methods against
12 criteria for method evaluation addressing four areas: ecological rationale, performance, feasibility of implementation,
and use in communication and management. Using these criteria, we identify and discuss three general challenges for those developing new methods for phytobenthos-based assessment: a weak ecological
rationale and insufficient consideration of the role of phytobenthos as a diagnostic tool and for communicating ecosystem health beyond a narrow group of specialists. The papers in the special series allow a comparison with the situation and approaches in the USA, present new
methods for the assessment of ecological status and acidification, provide tools for an improved management of headwaters and petrifying springs, discuss the utility of phytobenthos for lake assessments, and test the utility of functional measures (such as biofilm phosphorus uptake capacity, PUC).

In this paper we reinvestigated seven Surirella species described or reported by Gandhi and two taxa which were not reported by Gandhi using his collections from Peninsular India. Among these, S. langebertalotii Karthick, Hamilton & Kociolek stat. & nom. nov. is a new name for Surirella robusta f. minor.
Surirella leyana Bramburger & Hamilton and S. pinnigera Bramburger & Hamilton were new records to India. Surirella lanceolata Gandhi is a synonym of the cosmopolitan species S. ovalis Brébisson 1838 and for the fi rst time the ultrastructural details of S. shyamae Gandhi, S. capronioides Gandhi, and Surirella capronii Brebisson & Kitton are presented. This study confi rms that members of Surirella show different levels of endemism, such as some being locally endemic, some regionally distributed and others cosmopolitan. It is also evident that Peninsular India and the Malay Archipelago share a similar regional diatom fl ora.

Sampling campaigns associated with the ongoing PhyBiO project revealed the new presence of the benthic pinnate heterovalvar araphid diatom Licmophora normaniana. This species is considered cosmopolitan and is common on marine coasts. Based on literature searches, the following identification represents the first known occurrence in an inland mineral spring in the Siwa Oasis, the Western Desert of Egypt, and of this diatom species in mineral desert springs generally, or from any inland waterbody. The presence of L. normaniana was confirmed using light and scanning electron microscopy. Environmental variables (including major ions and metals) of this Saharan biotope were measured to characterize the habitat of this population. We hypothesize that the introduction of this marine species in the Siwa Oasis was related to fish farming activities carried out in the springhead by local inhabitants. We further hypothesize that the primary negative consequence of this invasion is likely to be the alteration of diatom community composition, with possible replacement of characteristic native taxa. Biological invasions place further pressure on spring habitats in oases, where they are affected by numerous growing human impacts, including global climatic changes. Therefore, legislation to protect these springs and enable sustainable and adaptive management, coupled with raised public awareness, is urgently needed to safeguard and conserve these unique biodiversity hotspots.

In 2000 the European Parliament and The European Union Council recommended that member countries assess water quality using diatoms, as part of the phytobenthos. In Italy this recommendation has given new impetus to the study of diatom communities and the application of biotic indices. During the summer of 2004, a total of 11 rivers of the Trentino province (Northern Italy) were sampled, revealing the presence in low abundances of the diatom Didymosphenia geminata (Lyngbye) M. Schmidt. The sites where this diatom occurred were characterised by a low pollution impact; they were also lake fed or had a regulated flow regime, although with different geologies. Morphological features of D. geminata frustules were analysed using LM and SEM and specimens could be referred to the morphotype "geminata". In many countries this species is expanding its distribution and in New Zealand it is considered an invasive alga. This work provides an initial report on the presence of D. geminata in the Trento province, and contributes to increasing the knowledge on its distribution in Italy and its ecology in the Alps.

The epiphytic algae on some aquatic macrophytes and related physical and chemical
properties of Al-Abbasyia-Euphrates river middle of Iraq were studied during the
study period from March 2012 to February 2013. Four sites between the Al-Kifil
districts extending to the Al-Abbasyia district selected.
The quantitative and qualitative of epiphytic algae on Phragmites australis and
Ceratophyllum demersum have studied. In addition to many physical and chemical
parameters such as air and water temperature, water flow, transparency, pH, electric
conductivity (EC), Salinity (‰), TDS, TSS, dissolved oxygen, BOD5, alkalinity, total
hardness, calcium and magnesium. A total of 209 epiphytic algal taxa belonging to
Bacillariophyceae (144), Chlorophyceae (39), Cyanophyceae (19) and
Euglenophyceae (2) recorded within the present study. Some algal taxa noticed
mostly dominant among both the study sites and periods. These were Cymatopleura
elliptica, Eunotia arcus, Nitizschia sp., Cymbella sp. and Gomphonema sp. This study
revealed the existence of some algal taxa on specific parts of the host macrophytes.
Where Sphaerocystis attached on the stem of C. demersum; Actinoptychus sp.
attached on the root of P. australis; Chaetoceros capense on the root of P.australus and Thalassiosira fluviatilis on the leaves of P. australis.
Keywords: Epiphytic algae, water quality, aquatic macrophytes, lotic
ecosystem, Al-Abbasyia river, euphrates river, Iraq

En esta obra se recogen los 200 taxones de diatomeas (pertenecientes a 60 géneros distintos) más importantes de las identificadas en más de 600 muestras de epiliton fluvial recogidas durante campañas de muestreo efectuadas entre 2003 y 2007 en la parte española de la cuenca, dentro de los programas de seguimiento del estado de las masas de agua superficiales de la Confederación Hidrográfica del Duero. Esta selección atiende a un doble criterio, que valora la importancia de cada taxón dentro del inventario general de la cuenca, de forma que se han considerado las especies más abundantes y/o más ampliamente distribuidas en la zona de estudio; así como, por su interés florístico o biogeográfico, se incluyen algunos taxones adicionales (especies exóticas, poco conocidas o que representan novedades para la Península). Para cada especie se ofrece la siguiente información: una descripción morfológica y autoecológica (parte II), un mapa de distribución en la cuenca del Duero (parte III) y una serie de fotografías en microscopía óptica de campo claro donde se ilustra la variabilidad morfológica de cada taxón, reunidas en 36 láminas (parte II).

The Castilla-La Mancha Region (south-central Spain) is scarcely studied in terms of freshwater algae. However, both the implementation of the Water Framework Directive (2000/60/CE) and the evaluation of the ecological state of European aquatic ecosystems have increased the intensity and frequency of water body monitoring, including the rivers, lakes and wetlands of this region. Thus, our knowledge on algal biodiversity and the geographical distribution of many species is rapidly increasing. In this study we describe the occurrence, ecological conditions and morphological characteristics of five algal species which are rare at the European level: Nostochopsis lobataWood ex Bornet & Flahault, Batrachospermum atrum(Hudson) Harvey, Chroothece richteriana Hansg., Oocardium stratum Nägeli and Tetrasporidium javanicum Möbius. In addition, we include Hydrurus foetidus (Vill.) Trev., a more common alga in Spain, since this is the first record for the region. Finally, we compare morphological and ecological characteristics of the studied populations with other European records.

It is thought that long-term monitoring is an essential tool through which conservationists and managers (i) are alerted when the system departs from the natural state, (ii) can check their environmental policy, and (iii) can detect disturbance effects. However, while long-term studies are growing in number, the lack of information on the background rates of natural changes could lead to a biased interpretation of results. In this study we analyzed the diatom composition of yearly samples (14 –16 yrs) in four springs with the following goals: (1) to estimate the consequences of sampling-related processes on the species composition and relative abundance; (2) to determine the form of the assemblages' variation, evaluating whether the assemblages can be predicted by cyclic, directional, or stochastic changes; (3) to test if, and to what extent, the diatom variability (variation in species composition, relative abundance and diversity) on a temporal scale is driven by the environment; (4) to evaluate the degree of temporal concordance among the diatom assemblages inhabiting four springs. Results showed that because the effect of sampling was inversely proportional to the species abundances, the presence of the least abundant species over the years were mainly a result of chance. The analyses allowed us to discriminate between stochastic and directional patterns, revealing the ongoing changes in two out of four springs. Because the environmental variables did not explain a significant portion of this variability, other hypotheses are put forward. The assemblages' dynamics of species composition over time were significantly synchronous in two out of six couples of springs, and regardless of the environment. This result can suggest that internal, within springs, drivers may be more important than extrinsic forces operating over regional spatial scales. Overall, these results provide a benchmark of diatom variability over time and in natural conditions delimiting the " limits of acceptable changes " .

The epipelic algae composition was srudied in two starions at Al-Adhaim river (st.l and St.2), and trvo srations at Tigris, before (St.3) and after 1st.+y ris m"eting *ittr Al-Adhaim river for the period beiveen June 1995 to February 1996. out of 6l identified taxa, 54 taxa berong to diatonis. A total or35 taxa was common benveen the two rivers.-The argar densiry rvas ranged between 300-32200 Jv.#'r', ,t r'r*oi.a area,. rvith higher densiry in rgris riier (St.3) at monthry average of i 3370 ceil/cml

The Lea Navigation in the north-east of London, a canalised reach of the River Lea, is affected by episodes of very low levels of dissolved oxygen. The problem was detected by the Environment Agency in the stretch from the confluence with Pymmes Brook (which receives the final effluent of Deephams sewage treatment works) to the Olympic area (Marshgate Lane, Stratford). In this project, possible causes and sources of the poor water quality in the Lea Navigation have been investigated using a multi-parameter approach. A study of physico-chemical parameters, obtained from Environment Agency automated monitoring stations, gave a clear picture of the poor river water quality at three sites in this reach. River water ecotoxicity to the freshwater alga Pseudokirchneriella subcapitata was determined by algal growth inhibition tests, following the OECD guidelines. Moreover, a novel protocol was developed which involved the use of E. coli biosensors (CellSense) operating at a lower potential than the standard protocol and using pre-concentrated river water samples. This protocol is promising and it has the potential to be a useful tool to determine the toxicity of contaminants at environmental concentrations.  Furthermore, the developed protocol is a rapid, easy to perform bioassay, with potential application in achieving the aims of the Water Framework Directive (WFD). In addition to the data from the environment Agency automatic monitoring stations and the laboratory-based tests, two in situ monitoring approaches were performed: 1) a detailed spatial seasonal monitoring of physico-chemical parameters of river water at twenty-three sites, and 2) algal growth inhibition tests, with algae entrapped in alginate beads, at seven monitoring stations. Results showed chronic pollution, and identified polar compounds in the river water and high bacterial concentrations as possible causes of low dissolved oxygen levels. This study confirmed the negative impact of Deephams STW (throughout Pymmes Brook) on the water quality of the Lea Navigation. However, there was evidence of other sources of pollution, in particular Stonebridge Brook was identified as uncontrolled source of pollution and untreated wastewater. Other possible sources include Old Moselle Brook, diffuse pollution from surface runoff, boat discharges and other undetected misconnections. Finally, in the light of the WFD, this project provides a case study on the investigation of river water quality, providing evidence that the multiparameter approach is reliable, and low cost approach for the monitoring of freshwater bodies.

Biotic indices based on macro-invertebrates and diatoms are frequently used to diagnose ecological quality in watercourses, but few published works have assessed their effectiveness as biomonitors of the concentration of micropollutants. A biological survey performed at 188 sites in the basin of the River Duero in north-western Spain. Nineteen diatom and six macro-invertebrate indices were calculated and compared with the concentrations of 37 different toxicants by means of a correlation analysis. Several chemical variables analysed correlated significantly with at least one biotic index. Sladecˇek’s diatom index and the number of macro-invertebrate families exhibited particularly high correlation coefficients. Methods based on macro-invertebrates performed better in detecting biocides, while diatom indices showed stronger correlations with potentially toxic elements such as heavy metals. All biotic indices, and particularly diatom indices, were especially sensitive to the concentration of fats and oils and trichloroethene.

Several methods for water quality assessment have been proposed for European rivers. The EU Water Framework Directive requires the use of ecological indicators for stream monitoring networks and has encouraged research on biological indices. However, there is a lack of integrative studies comparing the efficiency of such methods in the determination of the ecological status in rivers. The present work, carried out in the Spanish side of the Duero Basin, the largest in the Iberian Peninsula, aimed at comparing different water quality indices. The survey was conducted during autumn 2003 and summer 2004 in 95 sites covering the entire basin. Epilithic diatoms and benthic macroinvertebrates were sampled and analysed following standard methods for the calculation of the macroinvertebrate index IBMWP and 18 different diatom indices. Additionally, water physical and chemical variables were measured and Habitat (IHF) and Riparian (RQI) indices were determined in situ. In general, both diatom and macroinvertebrate indices were strongly correlated with each other and with abiotic factors. The highest correlation coefficients between water physical and chemical data (especially with the concentrations of phosphates and N-derived compounds) were obtained for the diatom index SPI and the IBMWP, though no biotic method detected changes in the concentrations of toxicants (Zn2+, Cr III). The use of diversity metrics as monitoring indices is not recommended. The results indicated that several different biotic indices, based on a wide range of biotic communities, must be integrated in water quality surveillance protocols, in order to reflect complementary aspects of the ecological status in river ecosystems.

En verano de 2005 se realizó un muestreo en 140 estaciones de la red ICA de la cuenca del Duero, a fin de determinar la calidad ecológica del agua en estos puntos utilizando diatomeas como bioindicadores. Los resultados muestran que el índice de diatomeas más apropiado para esta cuenca es el Índice de Poluosensibilidad Específica(IPS). Según este índice, el 61, 4% de los puntos alcanzan un estado ecológico de sus aguas "Bueno" o "Muy Bueno", cumpliendo con los objetivos determinados por la Directiva Marco del Agua. Sin embargo, el 38, 6% de los puntos no llegan a un nivel aceptable según dicho criterio.

Se propone un método para la toma de muestras de diatomeas epífitas en lagos y lagunas con el fin de aplicar dichas comunidades algales en la determinación del estado ecológico de estos sistemas acuáticos de acuerdo con los requisitos de la Directiva Marco del Agua. La metodología se basa en el empleo de muestradores tipo Kornijów para la recolección del epifiton desarrollado sobre helófitos. Los resultados preliminares muestran la eficacia de este método en la evaluación de la calidad del agua. La aplicación de esta sencilla metodología permite el empleo de las diatomeas epífitas como indicadores biológicos de los medio lacustres, generando resultados reproducibles en el tiempo y basados en un protocolo común fácilmente aplicable.

The present project deals with epipelic algae on lotic ecosystems in iraq. Benthic diatoms in Al-Shamiyah river was the concern of the present study. The river is adistanse from industrial activities within southern reagion of raq. Four sites along the river were chosen for sampling during the period March 2013 to January 2014. A total of 173 species of epipelic diatoms were identified. Within which was pennate diatoms predominated and represented about 92.49% of the total diatoms. The total number of diatoms ranged between 185.1-422.34 Cell x10 4 /cm 2. Twelve most common identified diatom species were Achnanthes affinis Grunow, Achnanthes mintussima Küetzing, Cocconeis placentula var. euglypta (Ehr) Cleve,Cymbella affinis Küetzing, Diatoma vulgare Bory, Fragilaria capucina Desmazieres, Gomphonema angustatum var. productu Grun., Navicula. lanceolata (Ag.) Kuetzing, Navicula. radiosa Küetzing, Navicula viridula Küetzing, Nitzschia. palea [Kutz]. W. Smith, Nitzschia romana Grunow. The status of physicochemical conditions and epipelic algal community indicated that the water of the river was clean to moderate quality wise.

Comparative morphological (including plastids) and ultrastructural (frustule) analyses of numerous taxa within the established diatom genus Neidium Pfitzer led to the conclusion that N. binodiforme
Krammer and N. binodis (Ehrenberg) Hustedt can be identified as striking exceptions. They would be more coherently allocated in a new freshwater benthic diatom genus, Neidiomorpha gen. nov. This proposed genus differs from Neidium mainly by the longitudinal structures (shallow “caves” in the mantle instead of distinct
canals at the junction between valve face and mantle), by areolation pattern (including the absence of renilimbi on the internal valve surface), and raphe endings (no silica flaps causing a bifurcate appearance of the polar endings and no central endings deflected towards opposing directions). Chloroplast number and arrangement (two valve- and girdle-appressed chloroplasts placed fore and aft in the two halves of the cell), overall valve outline, and ecology (preference for medium to high conductivity freshwaters) are likely to be further relevant distinctive elements. Observations on the distribution, and habitat and choriotope preference of the two species combined with the new genus are also provided.

A new benthic diatom species, Gomphonema vidalii sp. nov., is described with light (LM) and scanning electron microscopy (SEM) observations. It was found in three Mediterranean watercourses: Farfa stream (Central Italy), Bévéra and Paillon streams (South-Eastern France). Valves have a clavate shape and striae are slightly radial, the central ones being shorter than the others. One stigma and two to four stigmoid areolae are present in the central area. Only the central stigma is easily resolvable with LM. SEM analyses revealed that striae have double rows of bean-shaped areolae. The central stigma opens in the internal side of the valve as a slit in the central nodule, while the stigmoid areolae located around the central area are only externally visible. In connective view, an uninterrupted line of puncta is present on the valve mantle. G. vidalii belongs to the group of Gomphonema  species with doubly-punctate striae, feature which was considered by some authors typical of the genus Gomphoneis. Peculiar of Gomphonema vidalii is also the presence of an isolated punctum in the central area, different in structure from stigmata and stigmoids which can be found in some Gomphonema and Gomphoneis species.

Diatom indices developed in certain geographic regions are frequently used elsewhere, despite the strong evidence that such metrics are less useful when applied in regions other than that where species–environment relationships were originally assessed, showing that species have particular autoecological requirements in different geographic areas. The goal of this study was to develop a new metric, the Duero Diatom Index (DDI), aimed at monitoring water quality in Duero basin watercourses (NW Spain). In summer 2008 and 2009, a total of 355 epilithic diatom samples were collected following standard protocols. The 2008 samples were used to develop the DDI, whereas the samples collected during 2009 were used in the index testing. Weighted averages method was used to derive the autoecological profiles of diatoms with respect to pH, conductivity, biological oxygen demand, ammonia, nitrates, and phosphates. The optimum and tolerance values for the measured environmental variables were determined for 137 taxa with abundances and frequencies of occurrence above 1 %, and subsequent trophic indicator and sensitivity values were defined for the DDI. The correlation between the observed and the diatom-inferred nutrient concentrations was highest for phosphates (ρ S = 0.72). Significant statistical relationship were observed between DDI values and the chemistry-based General Quality Index values (p = 0.006) and the specific pollution index (SPI) diatom metric (p = 0.04). DDI has demonstrated a better correlation with water chemistry than SPI diatom metric.

Information available on the utilization of algae and cyanobacteria, with manifold potential applications in agriculture and biotechnology, for commercial biopesticide production is still scarce. We used the algal/cyanobacterial extract-larval contact method to assay in vitro against different developmental life cycle stages (the 2nd and 4th instars) of the cotton leafworm Spodoptera littoralis crude ethanolic extracts of five different algal and cyanobacterial species: Chara vulgaris (stonewort), Parachlorella kessleri, Ulva intestinalis, Cladophora glomerata (green algae), and the heterocytous cyanobacterium Nostoc carneum. All the algal and cyanobacterial treatments showed insecticidal activities against larvae of S. littoralis, with 2nd larval instars being more susceptible. In general, P. kessleri and N. carneum exhibited the highest insecticidal toxic effects while the stonewort C. vulgaris showed the lowest insecticidal activity. Effects of these algal and cyanobacterial treatments on larval duration, % pupal formation, pupal duration and weight, % moth emergence, adults’ fecundity and longevity, eggs’ hatching, sex ratios, and larval-pupal-moth malformations were discussed. Gas chromatography-mass spectrometry (GC-MS) analyses of the crude algal and cyanobacterial extracts revealed 29 compounds, mainly containing an array of saturated and unsaturated fatty acids, some essential oils, and terpene compounds like phytol. Insecticidal activities of the algal and cyanobacterial specimens can be attributed to the synergistic effects of the abovementioned phytochemical constituents, particularly fatty acids such as the polyunsaturated ω-6 linoleic, palmitic, oleic, myristic, α-linolenic, and 7, 10-hexadecadienoic acids. The coccoid green alga P. kessleri and the cyanobacterium N. carneum can thus be recommended as ecofriendly biopesticides for the integrated pest management of the cotton leafworm and other agricultural pests.

Although neglected for a long time by freshwater-ecology research, springs are very important habitats for biodiversity conservation. They are multiple ecotones, and are characterized by a remarkable variety of environmental conditions (e.g., from highlyshaded to UV exposed, from permanent discharge to intermittent flow, from still water to strong currents, from extremely-soft to carbonate-precipitating water, etc.). Moreover, springs are often amongst the last high-integrity, oligotrophic freshwater habitats in densely populated areas. Because of the high quality of their waters, the main impact affecting springs is capturing and water diversion. Climate-change driven reduction in precipitations in many areas is likely to determine an aggravation of this impact. It is thus important to document the rich and peculiar biodiversity of springs, also to establish reference conditions for bioassessment methods. Especially in non-acidic springs with running water, and coarse lithic substrata, cyanobacteria are often one of the most taxa-rich and abundant groups of photoautotrophs. The relatively-scarce information available in the literature is mostly referred to similar habitats, and not to spring habitats in the narrower sense. Papers dealing with the cyanobacteria of ambient springheads (=eucrenal) worldwide are still very rare. These were reviewed separating ambient springs in temperate and warm climate, and with special attention to key species, to cyanobacterial strategies allowing survival in oligotrophic headwaters (e.g., nitrogen fixation, phosphatases, anti-UV compounds, etc.), and to distribution patterns. The review also hopes to bolster new interest and research on this topic, and suggests some promising research directions.