Diatoma Vulgare Research Articles

The Diatom Diversity and Ecological Status of a Tufa-Depositing River through eDNA Metabarcoding vs. a Morphological Approach-A Case Study of the Una River (Bosnia and Herzegovina).

Tufa deposits in karst rivers are unique habitats created by mutual interactions between specific environmental and biotope features and inhabited by diatoms as a highly abundant and diverse algal group. This pilot study aimed to investigate the diversity of diatom communities on tufa depositing habitats and assess the Una River's ecological status using a comparative molecular and morphological approach for diatom identification. The 312 base pairs of the rbcL gene were barcoded and analyzed using MiSeq reads and amplicon sequence variants (ASVs) obtained by the DADA2 pipeline. The reference database Diat.barcode v7 was used for taxonomic assignment. The morphological identification of the diatoms was carried out in parallel. In total, the combined dataset revealed 46 taxa identified at genus rank, 125 on the subgenus, and 145 on combined taxonomy rank. The metabarcoding approach mostly leads to a lower number of identified taxa at species rank (58 in molecular vs. 119 in optical inventory), resulting in higher values of beta diversity and heterogeneity in diatom assemblages in samples obtained by morphological approach. Despite the high percentage of taxonomically not assigned diatom ASVs to the species rank, high Shannon diversity index values and a similar number of taxa per locations compared to the morphological approach were obtained. Taxa Achnanthidium minutissimum (Kützing) Czarnecki, Achnanthidium pyrenaicum (Hustedt) H.Kobayasi, Amphora pediculus (Kützing) Grunow, Diatoma vulgaris Bory, Navicula cryptotenella Lange-Bertalot, and Navicula tripunctata (O.F.Müller) Bory were identified at all locations in both inventories. Although limited consistency in the diatom abundances between the two inventory datasets was found, a similar grouping of samples was observed connected to the river's longitudinal gradient. The data obtained using molecular approach in most sites indicated a mostly lower ecological status (good or moderate) compared to the data obtained from the morphological approach (high, good, and moderate). The potential of environmental DNA (eDNA) diatom metabarcoding for water monitoring and diversity studies is undeniable, but to fully realize the benefits of these methods in the future, it is essential to standardize protocols and expand the reference database for species found in specific habitats, such as tufa deposits.

Competition in the Periphytic Algal Community during the Colonization Process: Evidence from the World's Largest Water Diversion Project.

Periphytic algal colonization is common in aquatic systems, but its interspecific competition remains poorly understood. In order to fill the gap, the process of periphytic algal colonization in the Middle Route of the South to North Water Diversion Project was studied. The results showed that the process was divided into three stages: the initial colonization stage (T1, 3-6 days), community formation stage (T2, 12-18 days) and primary succession stage (T3, 24-27 days). In T1, the dominant species were Diatoma vulgaris (Bory), Navicula phyllepta (Kützing) and Fragilaria amphicephaloides (Lange-Bertalot) belonging to Heterokontophyta; these species boasted wide niche widths (NWs), low niche overlap (NO) and low ecological response rates (ERRs). In T2, the dominant species were Diatoma vulgaris, Cymbella affinis (Kützing), Navicula phyllepta, Fragilaria amphicephaloides, Gogorevia exilis (Kützing), Melosira varians (C.Agardh), Phormidium willei (N.L.Gardner) and Cladophora rivularis (Kuntze). These species displayed wider NWs, lower NO, and lower ERRs than those in T1. In T3, the dominant species were Diatoma vulgaris, Cymbella affinis, Navicula phyllepta, Fragilaria amphicephaloides, Achnanthes exigu (Grunow), etc. Among them, Heterokontophyta such as Diatoma vulgaris and Cymbella affinis had a competitive advantage based on NWs and ERRs. Cyanobacteria like Phormidium willei lost their dominant status due to the narrower NW and the increased NO. It could be concluded the interspecific competition became fiercer and shaped the colonization process; this study will be helpful in understanding the colonization of periphytic algal communities.

Responses of Phytoplankton Communities to Flow Regulation in Northeastern Riverine Wetlands of China

Among the impacts of dam construction on river ecosystem, runoff regulation and habitat fragmentation are the two major concerns. Herein, the response characteristics of phytoplankton communities to reservoir impoundment and dam interception were explored by taking Manjiang and Songjiang rivers, where a man-made engineering project was constructed, and the natural stretches located in the up-streams as the research objects. The results obtained revealed that the compositions of phytoplankton communities, collected from the 21 sampling sites in the riverine wetlands of reservoir stretch, flow-reduced stretch, and natural stretch, were dissimilar. The communities of phytoplankton were clustered into three groups. The co-occurrence network analysis indicated that the interspecific relationship structures of phytoplankton communities of each group were different. The indicator species Chlamydomonas ovalis, Synedra acus, and Chlamydomonas globosa, belonged to the Reservoir Wetlands Group, Diatoma vulgare, Fragilaria ca pucina, and Meridion circulare belonged to the Flow-reduced Wetlands Group, and Ceratoneis arcus and Treubaria crassispina belonged to the Natural Wetlands Group. The functional group L0 was the absolute dominant group in all three groups of the riverine wetlands, but a discrepancy was that the proportions of functional group X2 and functional group C in the Reservoir Wetlands Group were remarkably higher, while the proportion of functional group MP in the Flow-reduced Wetlands Group was noticeably higher. By assessing the status of the phytoplankton community composition and the functional group structure, we concluded that current velocity and water depth were crucial influencing factors, and the functional group structure based on the classification of livable water could be applied as a good indication for demonstrating phytoplankton community succession.

Bone and Tooth: Substrates for Determining Drowning: A New Diagnostic Procedure in Forensic Medicine Practice?

IntroductionDiatom tests are rarely used during autopsy to confirm drowning as the cause of death (COD) because of limitations of the current literature involving these techniques. Instead, experts rely on physical examination by the pathologist. Due to interpretive concerns regarding Diatom tests, they are often insufficient in establishing a diagnosis, but offer the potential to be an extremely useful diagnostic tool with further understanding. The aim of study is to optimize “Diatom Tests” for use in forensic medicine in Bosnia and Herzegovina. MethodsA randomized prospective experimental study was conducted, using albino Wistar rat models (Rattus norvegicus), at the Veterinary Facility, University of Sarajevo. Thirty-two adult albino rats, were used and distributed into groups as follows: Group A (6 deceased rats with COD other than drowning, but due to mechanical asphyxia, which were then submerged for 1 hour after death); Group B (6 deceased rats with COD other than drowning, but due to mechanical asphyxia, which were then submerged for 72 hours after death); Group C (6 rats that were immediately autopsied after drowning, with COD determined as drowning); Group D (6 rats that underwent a 48-hour postmortem period after drowning); Group E (COD: drowning, post-mortem 72hrs after death, remained submerged in water until PM).Live algological material was collected for the research of the systematics of algae from the Bosna river, Sarajevo, and transported to the University of Sarajevo (Department of Biology, Faculty of Science). Periphyllon, epiphyllon and epipelon were used to collect phytobenthos. The material was fixed with 4% formalin solution. Laboratory processing of diatoms was performed using the methods described by Hustedt (16). In the process of obtaining pure diatom valves, part of the material is digested with potassium permanganate (KMnO4), sulfuric acid (H2SO4), and oxalic acid (C2H2O4). In the next step, the cleaned diatom valves were mounted in Canadian balsam. A light microscope under 1000x magnification (Best Scope 2020) was used to evaluate and analyze the species. The identification of diatoms was performed using the reference of Cantonati et al (17). The nomenclature of diatom species was performed according to Guiry & Guiry's worldwide electronic internet database. ResultsNo diatoms were found in Groups A and B. However, Navicula sp. and Sellaphora sp. cf., were discovered during bone analysis of Group C where rats were immediately autopsied after drowning. Hantzschia amphioxus taxon was present in Group D, which underwent a 48-hour postmortem period after drowning and before samples were taken.In Groups C and D, where drowning was the COD, Diatoma vulgaris i Pinnularia major, Achnanthidium minutissimum i Melosira varians were present in the tooth samples. ConclusionOptimization of the “Diatom Test” method could potentially lead to its future use as a routine method within experimental settings. This experimental study is a starting point that guides forenscic medicine pracitioners towards the optimization of tests and sampling in cases of unexplained etiology, where preserved soft tissue structures is not available. In these cases, teeth and bones serve as accessible materials for diagnosing COD, alongside standardized nonspecific findings in the absence of organs for micro- and macroanalysis.

Using Algal Indices to Assess the Ecological Condition of the Aras River, Northwestern Iran

This work is the first in a series, and its purpose is the comprehensive assessment of the ecological state of the Aras River using biological indicators of water quality by diatoms based on species’ ecological preferences, pollution indices, statistics, and ecological mapping. Samples of diatoms and soft algae and measurements of water quality were analyzed at sixteen sampling sites (between 2020 and 2022) along the Aras River. The impact of anthropological activity on the river was monitored concerning water quality, river health, and ecosystem function. The physical and chemical characteristics of the water were measured. The biological properties of the algal periphyton communities, including species composition, were also measured. Based on the studies conducted in this research, 280 species were identified. The most prosperous species were Diatoma vulgaris, Amphora ovalis, Cocconeis placentula, Rhoicosphenia abbre-viatae, Cymbella helvetica, Brevisira arentii, Navicula tripunctata, Nitzschia linearis, Microcystis botrys, Microcystis aeruginosa, Pseudanabaena limnetica, Scenedesmus obliquus, and Pleurosira laevis (a pollution-resistant and salinity-resistant species first found in aquatic habitats in the Aras River). As a result, the empirical data and algal indices showed the river’s lower reaches to be in poor condition. Exploration of the algal assemblage and water chemistry data using computationally unconstrained ordination techniques such as principal component analysis (PCA) and canonical correspondence analysis (CCA) indicated two strong gradients in the data sets. The results support that water body classification is a function of water chemistry and biological and hydrological characteristics, as it is necessary to include pollutant effects on biota since the nature of the receiving waters influences the river’s water quality.

Spatial and Temporal Heterogeneity and Ecological Health Evaluation of Diatom Community Based on eDNA

In recent years, environmental DNA (eDNA) has been widely used in aquatic biodiversity monitoring, and how to establish a river ecological health assessment method based on eDNA has become a hot topic. This study was intended to develop a molecular diatom index based on eDNA to indicate the ecological health status of rivers under the influence of human activities. Firstly, the diatom community composition and structural changes in the Shaying River basin in spring and autumn were monitored through eDNA, and the driving environmental factors of the diatom community were diagnosed. Further, four strategies (OTU-taxonomy, OTU-free, ASV-taxonomy, and ASV-free) based on eDNA metabarcoding data were compared, and a molecular diatom index suitable for ecological health assessment in the Shaying River basin was constructed. The results showed that: ① there were seasonal differences in diatom community structure, and Discostella pseudostelligera, Nitzschia amphibia, Diatoma vulgaris, and other groups were the main factors to distinguish the seasonal differences. ② Mn, Fe, and TN were the main environmental factors affecting diatom community structure in spring, whereas COD and Cu were the main environmental factors affecting diatom community structure in autumn. ③ Among the four strategies, the diatom index calculated based on OTU-free data better reflected the environmental gradient change; the diatom index showed that the ecological health status of the Shaying River Basin was better in autumn than that in spring in time and better in the upstream than that in the downstream in space. In conclusion, this study monitored diatom community in Shaying River in spring and autumn through eDNA and constructed the molecular diatom index in the Shaying River basin, which promoted the application of eDNA to evaluate river ecological health.

Phytoplankton diversity in relation to physicochemical attributes and water quality of Mandakini River, Garhwal Himalaya.

Phytoplankton are important biological indicators of water quality. This current study assessed the physicochemical parameters and phytoplankton diversity of Mandakini River, an important tributary of the River Ganga. Water and phytoplankton samples were collected from three sampling sites located at three different altitudes for a period of twelve months (July 2018-June 2019). Water samples were analyzed for fourteen important physicochemical parameters along with the identification of phytoplankton by following the standard methodology. A total of 21 species of phytoplankton under three major groups Bacillariophyceae (Cymbella aequalis, Diatoma vulgaris, Fragilaria arcus, Frustulia rhomboids, Gomphonema geminatum, Navicula confervacea, Nitzchia diversa, and Synedra ulna); Chlorophyceae (Volvox sp., Cladophora glomerata, Closterium longissima, Hydrodictyon sp., Microspora amoena, Spirogyra sp., Oedogonium sp., Ulothrix zonata, and Zygnema cylindrospermum); and Cyanophyceae (Anabaena ambigua, Chlorococcum humicola, Nodularia sp., and Oscillatoria sancta) were observed and recorded during the study period. Site S3 (Rudraprayag) had the highest species diversity. From this study, the effect of physicochemical parameters on the diversity and density of phytoplankton was observed. It also includes the overall significance of phytoplankton and physicochemical parameters to the water quality of the Mandakini River along with the key factors that were responsible for the degradation of water quality. The current study also provides baseline information to future researchers working in a similar discipline.

Relationship between the structure of phytoplankton community and environmental factors in the Zhangye section of Heihe River

为探究黑河张掖段浮游植物群落季节动态及其与环境因子的相互关系，于2017年对黑河张掖段10个断面进行4个季度的采样调查，共计检出浮游植物8门80属316种，其中蓝藻门、绿藻门和硅藻门种类分别占总种类数的10.75%、15.22%和68.35%.水环境因子中，温度、电导率、盐度、溶解氧和叶绿素a浓度时空变化显著，总氮、总磷浓度则随着海拔降低而呈现显著升高的趋势.调查期间，黑河张掖段浮游植物密度在0.92×10⁴~116.67×10⁴ cells/L之间，从上游到下游呈现明显的递增趋势.优势种主要集中在硅藻门，包括扇形藻（Meridion sp.）、弧形峨眉藻（Ceratoneis arcus）、极小曲壳藻（Achnanthes minutissimum）、延长等片藻细弱变种（Diatoma elongatum var.tenuis）、尖针杆藻（Synedra acus）、简单舟形藻（Navicula simplex）、谷皮菱形藻（Nitzschia palea）、变异直链藻（Melosira varians）、普通等片藻（Diatoma vulgaris）、肘状针杆藻（Synedra ulna）等，此外，在河段优势种中，中下游出现蓝藻门的微囊藻（Microcystis sp.）（优势度为0.025）、绿藻门的四尾栅藻（Scenedesmus quadricauda）（优势度为0.020）、隐藻门的尖尾蓝隐藻（Chroomonas acuta）和卵形隐藻（Cryptomonas ovata）（优势度为分别为0.045和0.032）种类.4个季度Shannon-Wiener多样性指数（H'）均值分别为2.65、2.76、2.89和2.44，Pielou均匀度指数（E）均值为0.93、0.90、0.91和0.87，Margalef丰富度指数（d）均值为1.73、1.77、2.00和1.31.随着海拔的降低，浮游植物H'和d显著升高，而E变化范围相对平稳.结合水体营养盐指标、浮游植物及多样性指数等指标对水质评价，黑河张掖段水质总体呈无污染或轻度污染到轻中度污染状态，且中游污染程度加剧.RDA与Pearson相关性分析结果表明，水体氮磷营养盐、温度、海拔是影响黑河张掖段浮游植物群落结构及动态的关键因素，而在河段下游，电导率、盐度也是影响浮游植物群落结构的主要环境因子.;In order to investigate the various seasonal dynamics of the phytoplankton community and the correlation with environmental factors in the Zhangye section of Heihe River, the samples of the phytoplankton and the aquatic environment from 10 different river segments were assessed in 2017. A total of 316 species belonging to 8 divisions and 91 genera including the variants were identified to be mainly composed of the Chlorophyta, Cyanophyta and Bacillariophyta in the proportions of 10.75%, 15.22% and 68.35%, respectively. The environmental factors such as the temperature, conductivity, salinity, dissolved oxygen and chlorophyll-a displayed significant temporal and spatial changes, while the total nitrogen and total phosphorus showed a significant increase with the decrease in altitude. During the survey period, the density of the phytoplankton in the Zhangye section of Heihe River was 0.92×10⁴-116.67×10⁴ cells/L, with the existence of a significant increasing trend from upstream to downstream. The dominant species mainly belonged to Bacillariophyta and included Meridion sp., Ceratoneis arcus, Achnanthes minutissimum, Diatoma elongatum var. tenuis, Synedra acus, Navicula simplex, Nitzschia palea, Melosira varians, Diatoma vulgaris, Synedra ulna etc. In addition, it was found that Chlorophyta species Microcystis smithii (McNaughton index Y was 0.025), Cyanophyta species Scenedesmus quadricauda (Y value was 0.020) and Cryptophyta species Chroomonas acuta and Cryptomonas ovata (Y values were 0.045 and 0.032, respectively) were prominent in the middle and lower reaches of the river. With reference to the algal diversity in four quarters, the averages of Shannon-Wiener index (H') were 2.65, 2.76, 2.89 and 2.44, while Pielou evenness index (E) were 0.93, 0.90, 0.91 and 0.87 and Margalef diversity index (d) were 1.73, 1.77, 2.00 and 1.31, respectively. With the decrease in altitude, the H' and d were seen to increase significantly while the range of E remained relatively stable. Through the comprehensive evaluations of the water physicochemical index together with the density of algae and their diversity, the water quality in the Zhangye section of Heihe River was found to range from being unpolluted to light or moderately polluted. However, the levels of pollution in the middle reaches appeared to be aggravating. Meanwhile, the results of redundancy analysis and Pearson analysis for the relationship between the phytoplankton and the environmental factors showed that the factors such as total nitrogen, total phosphorus, temperature and elevation played a key role in affecting the structure and dynamics of the phytoplankton community in the Zhangye section of Heihe River. In the downstream regions of the river, factors such as conductivity and salinity were found induce a similar effect on the phytoplankton community structure.

Водоросли и беспозвоночные реки Чикой и ее притоков

The Chikoy is a taiga river of the Lake Baikal basin, the biggest tributary of the Selenga River. It is slightly developed and is characterized by the intact state of the natural complexes. The article presents the data on the features of the plankton qualitative and quantitative development in the river middle range and its tributaries such as the Kunaley, the Ashgaley, the Cheryomushka, the Goryachaya, the Solontsovaya and the Bolshaya Burecha (Transbaikal Kray). However, data on the river plankton, available today, are insufficient and fragmented. Studies conducted in May and July 2017 made it possible to establish that the taxonomic composition of the plankton in some tributaries of the Chikoy River (middle course) is extremely poor and is represented by 57 taxa below the genus (34 algae and 23 invertebrates). Diatom algae (up to 80%) and rotifers (up to 60%) dominated in species richness. Species Fragilaria capucina, Gomphonema lanceolatum, Diatoma vulgaris, D. vulgaris var. producta, Hannaea arcus, Ulnaria ulna were dominants in phytoplankton. The algological composition and its dominant forms in the studied rivers were similarity. In the zooplankton, a single complex of dominant species, characteristic of all watercourses, has not been identified. The taxonomic composition and abundance of invertebrates were very poor. In the course of the work carried out, it was established that, despite the geographical position and mountain character of the river, the share of cold-loving species in plankton does not exceed 10.5% – for algae and 7% – for zooplankton. The poor species composition and density of plankton algae and invertebrates correspond to the oligotrophic type of watercourses. The obtained data are primary and can be used for further biological monitoring of the watercourse related to the Baikal basin.

Uncertainty of using habitat fidelity in biomonitoring based on benthic diatoms - the Raška River case study

Epilithic diatoms are frequently recommended for river biomonitoring, while much less emphasis is placed on epiphytic communities. This study considers use of epiphytic and epilithic diatom communities from the Raska River in biomonitoring. A total of 212 diatom taxa were recorded in both communities. Dominant diatoms were Achnanthidium minutissimum (Kutzing) Czarnecki, A. affine (Grunow) Czarnecki, A. subatomus (Hustedt) Lange-Bertalot, Amphora pediculus (Kutzing) Grunow, Diatoma vulgaris Bory, Gomphonema tergestinum (Grunow) Fricke, Cocconeis placentula var. lineata (Ehrenberg) Van Heurck, Melosira varians Agardh and Navicula tripunctata (Muller) Bory. Redundancy analysis (RDA) was used to detect the relationships between diatoms, some environmental factors and sampling sites. Diatoms of the epiphytic community showed a clearly grouping in relation to the sampling sites as compared with diatoms of the epilithic community. Species common to both communities showed a similar correlation with some environmental variables (BOD, pH, NH4+, TP, NO3− and conductivity), with three exceptions (Diatoma vulgaris, Cymbella compacta, and Encyonema silesiacum). Pearson’s correlation coefficient showed correlation between selected environmental variables and diatom indices calculated using OMNIDIA 6.2 software (TDI, IPS, CEE, GENRE, TID, SID, SHE and IDSE/5). Diatoms of the epiphytic community are more clearly clustered in relation to the sampling sites as compared with diatoms of the epilithic community. According to our results there is still “place” in biomonitoring for epiphytic community. The present study highlights the necessity of sampling both epiphytic and epilithic communities because substrate specificity could play important role in biomonitoring.

The N:P:Si stoichiometry as a predictor of ecosystem health: a watershed scale study with Ganga River, India

ABSTRACTThe present study was conducted from March 2016 to February 2017 to investigate human-driven shifts in N:P:Si stoichiometry along a 2320 km stretch of the Ganga River. Concentrations of nutrients ( , and ), dissolved organic carbon (DOC) and dissolved silica (DSi) were measured in river water and in surface runoff to explore possible role of lateral flow and evaluate if there was a shift in the elemental stoichiometry of N, P and Si. Our study revealed that catchment runoff is an important factor, in addition to urban-industrial flushing, enhancing nutrient enrichment causing a shift in N:P:Si ratios leading to N limitation over P (N:P < 16:1) and Si limitation over N (N:Si > 1). Among the seven dominant diatom genera considered here, diatom abundance changed with concurrent changes in water chemistry. Sites with overall low N:P ratios favoured P-loving species such as Diatoma vulgaris, Fragilaria intermedia and Gomphonema parvulum. The study shows that the N:P:Si stoichiometry if coupled with changes in diatom abundance may be a useful predictor of anthropogenic environmental effects in the Ganga River. This watershed scale study invite attention towards significance of N:P:Si stoichiometry for properly addressing the eutrophy and efforts to rejuvenate the river.

The Application of Benthic Diatoms in Water Quality Assessment (Mlava River, Serbia)

AbstractThe main objective of this study was to assess the ecological status of the Mlava River based on epilithic diatoms and to test the use of diatom indices as a tool for estimating the quality of flowing waters in Serbia. Quantitative analysis showed that in AprilAchnanthidium minutissimumwas dominant at each site, except at the fifth site, whereAmphora pediculuswas dominant. In July and September,Achnanthidium minutissimum, Achnanthidium pyrenaicum,Amphora pediculus,Denticula tenuis,Diatoma vulgaris,Gomphonema elegantissimum,Cocconeis pseudolineataandCocconeis placentulavar.lineatadominated. Detrended correspondence analysis (DCA) was used to detect the major patterns of variation in species composition. The first DCA axis summarizes the distribution of the diatom community, mainly through temperature, conductivity, oxygen and water hardness gradient. The second DCA axis was weakly correlated with few variables. Based on the average values of the pollution sensitivity index (IPS), commission for economical community metric (CEE) and biological diatom index (IBD), the water of the Mlava River belonged to water class I during all three seasons. Values of the diatom-based eutrophication/pollution index (EPI-D) indicated class II water quality. According to calculated trophic diatom index (TDI) values, water of the Mlava River was characterized by intermediate nutrient concentrations during three seasons. Principal components analysis was used to represent the correlation between diatom indices, and the highest correlation among the selected diatom indices is seen between EPI-D, IPS and IBD.

Epiphytic and epipsammic diatom communities of Gölbaşı Lake (Adıyaman-Turkey)

The present study examined certain physical and chemical parameters in epiphytic and epipsammic diatoms identified on Potamogeton perfoliatus and Chara sp. collected from an area of one square kilometers in Golbasi Lake located within the borders of Adiyaman city from March to October 2014.Over the course of the study, 14 taxa belonging to epiphytic diatoms and 24 taxa of epipsammic diatoms were identified. Among the epiphytic diatoms, Amphora ovalis, Diatoma vulgaris and Ulnaria ulna were the most significant ones in terms of abundance and individual occurrences, while among the epipsammic diatoms the most remarkable ones were Navicula salinarum, Navicula radiosa, Nitzschia linearis and Cyclotella comta with regard to abundance and individual occurrences. According to Sorensen Index the highest similarity (78%) was found between diatoms on Potamageton perfoliatus and Chara sp. The similarity between epiphytic and epipsammic diatoms was only as high as 26% and 30%. Accordingly, the macrophyte preference of diatoms as a substratum was to a large extent similar. Diatoms displayed the highest level of development in late spring and summer, when there is more light and temperatures are higher. Keywords: Epiphitic diatoms, Epipsammic diatoms, Sorensen Similarity Index, Golbasi Lake, East Anatolia, Turkey

A Contribution to the Epipelic Algal Ecology in Lotic Ecosystem of Iraq

The study was conducted on epipleic diatoms in a lotic ecosystem. The Al-Shamiyah River was selected which is a distance from industrial activities. Four sites along the river were selected for sampling during the period from March 2013 to February 2014. A total of 173 species of epipelic diatoms were identified. The pennate diatoms predominated and represented about 92.49% of the total diatoms, while centric diatoms formed only 7.51%. The total number of diatoms ranged between 185.1 - 422.34 cell × 104/cm2. Some of the pennate 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 physicochemical and epipelic algae species indicated that the water quality of the river was clean to moderate water quality.

Response of planktonic cyanobacteria and periphyton assemblages to physicochemical properties of stormwater in a shallow urban lake

The aim of this study was to determine the response of planktonic cyanobacteria and periphyton assemblages (periphytic algae in the separator pipes, epilithon and epiphyton) to lamella separator-treated stormwaters in urban Lake Jeziorak Maly in 1997-2003 and 2005. Relationships between periphyton and phytoplankton assemblage and water chemistry variables were analyzed by calculating the Spearman’s rank correlation coefficient, and then with canonical correspondence analysis (CCA). The basic factors favouring the cyanobacterial growth were water temperature and iron, while high chloride concentration limited their development. Cyanobacterial abundance recorded at the separators was half that of the pelagic zone because of a lower water temperature and higher Cl concentration, indicating high algal sensitivity to the considerable velocity and disturbances caused by stormwater effluents. Higher silicon and calcium concentrations at the separators and orthophosphates at sites with stones and gravel showed connection with the growth of diatoms, especially Fragilaria leptostauron var. martyi, Diatoma vulgaris and Navicula gregaria. The richness of the dominant cyanobacteria, Aphanizomenon gracile and Limnothrix redekei, was related with the water temperature, conductivity, pH, and TN. Similarities in the periphyton dynamics in separator pipes and epilithon between the years covered by the study suggest significant influence of separator-treated stormwater on these assemblages, in contrast to epiphyton and phytoplankton in the pelagial zone, where these waters had limited influence.

The relationship between epilithic diatom communities and changes in water quality along the lower Han River, South Korea

Epilithic diatom communities were sampled every two weeks from February 2001 to February 2002 at three sites in the lower Han River (LHR), South Korea, to investigate how epilithic diatom communities reflected longitudinal gradients in environmental quality measures. The water quality in the LHR differed between the rainy and dry seasons and also varied at different sites according to levels of pollution. The epilithic diatom communities responded to changes in the aquatic environment and hydrological characteristics. There were few predominant diatom species during the rainy season, and they were found at lower concentrations than in the dry season because of the high current velocities caused by heavy rainfall. The predominant species at the three study sites in the LHR were different because of the effects of eutrophication gradients. Cocconeis placentula, Diatoma vulgaris, and Nitzschia dissipata were dominant at site 1 (clean to nutrient-rich conditions). Fragilaria capucina var. gracilis and Gomphonema parvulum were dominant at site 2 and their growth was accelerated by the moderately-nutrient-rich conditions. Luticola goepperitnana, N. palea, small Nitzschia spp., and small Navicula spp. were dominant in the most polluted pools at site 3. We conclude that the LHR has a water quality gradient along its course, and that this causes marked changes in the epilithic diatom species compositions found along the river. The results confirm that epilithic diatoms are important bioindicators for assessing ecological quality in the LHR.

KELIMPAHAN CHRYSOPHYTA PADA MEDIA BUDIDAYA IKAN NILA YANG DIBERI PAKAN FERMENTASI DENGAN PENAMBAHAN TEPUNG KULIT UBI KAYU DAN PROBIOTIK

Chrysophyta is also known as golden-yellow algae because of the yellow dominant pigment of carotene and xanthophyll. This study aimed to determine species richness and abundance of Chrysophyta in the Tilapia culture media which was fed with the addition of cassava peel flour and probiotic. The method applied in this study was the experimental method with 4 treatments, i.e.: the use of fermented feed with the addition of cassava peel flour (0%, 25%, 50%, and 75%) and probiotic in Tilapia culture media. Each treatment was replicated 4 times. Sampling was carried out 6 times at intervals of 2 weeks. The observed parameters were the main parameters, i.e.: the number of Chrysophyta species and individuals; and supporting parameters, i.e.: water temperature, pH, TDS, TSS, NO3, NO2, BOD5, DO, and total of phosphate. Species richness and abundance of Chrysophyta data were analyzed using cluster analysis based on Bray-Curtis similarity coefficient. The analysis continued with Similarity Percentages (SIMPER) analysis to determine the contribution of species to the similarity index in each group or to dissimilarity index amongst groups. The results showed that the species richness found in the Tilapia media culture which was fed with the addition of cassava peel flour and probiotic consist of 20 species belonging to a class namely Bacillariophyceae. Abundance of Chrysophyta obtained was ranged from 5.160-13.292 individuals/liter. The cluster analysis showed that Chrysophyta amongst treatments have a quite high similarity level (&gt; 50%) was ranged between 65.56% -83.99%. Contributions of species which contribute the highest similarity index were Diatoma vulgare (49.80%), Navicula brachysira (70.50%) and Navicula platystoma (82%).

Gastropods and periphytic algae relationships in the vicinity of a small hydroelectric plant on the Pas³êka River in northeast Poland

Abstract This study of periphytic algae and gastropods differentiation on macrophytes, stones, and dam substrates and the relationships between these communities in the vegetative season of 2001-2003 was conducted in the vicinity of a hydroelectric plant on the Pasłeka River. Damming the river caused decreased water discharge upstream from the plant, and increased it downstream. Thus, oxygen conditions downstream from the plant improved, but high nutrient concentrations were also recorded. Generally, increased orthophosphate concentrations do not allow river waters to be classified as having good or maximum ecological potential. Damming contributed to changes in the growth conditions of the periphytic algae and gastropods and their differentiation. The highest biomass of periphytic algae was noted on the dam, while the highest gastropods biomass was noted on macrophytes. The periphytic algae was dominated by the diatoms Diatoma vulgaris and Melosira varians (epiphyton, dam) and the chlorophytes Ulothrix tenuissima and Spirogyra sp. (epilithon), while the gastropods were dominated by Lymnea stagnalis (macrophytes), Theodoxus fluviatilis (stones), and Radix balthica (dam). The relationship between the gastropods and the periphytic algae on macrophytes and the dam in spring and summer revealed an increase in gastropods biomass and a decrease in periphytic algae biomass. This was indicated by the negative correlation between the biomass of these communities.

DIATOMS (BACILLARIOPHYCEAE) IN RIVERS AND STREAMS AND ON CULTIVATED SOILS OF THE PODKARPACIE REGION IN THE YEARS 2007–2011

Diatoms Bacillariophyceae are a specialized, systematic group of algae, living in different types of ecosystems, and they are very good indicators of water quality. Recently, detailed studies have been carried out in the territory of the Podkarpacie Province on the diversity of diatoms in running waters. The area of study covers mostly the catchment of the biggest rivers of the province (mainly the Wislok River) and cultivated soils. Running waters in the Podkarpacie Province are characterized by a huge species richness of diatoms, 738 different taxa have been found so far. The highest number of taxa was noted in the Wislok River (400), while the Żolynianka and Rozanka streams and the Mleczka were also characterized by huge diversity (from 200 to over 350 taxa). In the majority of studied sites diatoms of alkaline (pH>7) and nutrient rich (eutrophic) waters dominated: Navicula lanceolata, N. gregaria, N. capitatoradiata, Nitzschia palea, N. dissipata ssp. dissipata, Achnanthidium minutissimum var. minutissimum, A. pyrenaicum, Amphora pediculus, Diatoma vulgaris, Rhoicosphenia abbreviata, Planothidium lanceolatum, Cocconeis pediculus and C. placentula var. lineata. About 150 taxa were indentified on cultivated soils, among which the largest populations were formed by Hantzschia amphioxys, Mayamaea atomus, Nitzschia palea, N. pusilla, Pinnularia obscura and Stauroneis thermicola.

Influence of environmental variables on phytoplankton floristic pattern along the shallow coasts of southwest Bay of Bengal

Multivariate statistical methods are used to study the spatial and temporal variations of physico-chemical parameters and phytoplankton floristics of the southwest coast of Bay of Bengal. Over 94 species of phytoplankton represented by 77 species of diatoms, 11 species of dinoflagellates and 6 species of blue-green algae were recorded. Higher phytoplankon species diversity was found in premonsoon when salinity and nitrate concentrations were low and reactive silicate and inorganic phosphates were moderate, while species diversity was low during summer with when increased sea surface temperature, salinity and low nutrients availability. During summer season Coscinodiscus centralis, Diatoma vulgare and Rhizosolenia alata were dominant, especially Coscinodiscus sp. distributed in all stations whereas Skeletonema costatum, Biddulphia sinensis and Ditylum brightwelli were abundant in the premonsoon season. From principal component analysis and multiple regression analysis, it is evident that variables like sea surface temperature and light extinction coefficient are the most important factors influencing the seasonal pattern of phytoplankton population, although nutrients like nitrate, inorganic phosphate and silicate have also important contributors in deriving phytoplankton population density of this part of the Bay of Bengal.