Phytoplankton Species Diversity Research Articles

Species diversity and community structure of phytoplankton in the Velikaya Salma Strait (Kandalaksha Bay, White Sea) in 2021

The species diversity and community structure of phytoplankton in the Velikaya Salma Strait (Kandalaksha Bay, the White Sea) were investigated from May to September 2021. A total of 128 algal taxa were identified, comprised of diatoms (80% of the total phytoplankton species number), dinophytes (15%), cyanobacteria (3%), ochrophytes (1%) and cercozoans (1%). The phytoplankton abundance varied from 1.84х106 cells/m3 (in August) to 23.27х106 cells/m3 (in July); phytoplankton biomass varied from 31.4 mg/m3 (in May) to 246.7 mg /m3 (in July). Diatoms was the dominant group in terms of quantity and biomass, one dinophyte species, Sсrippsiella acuminata, was dominant in terms of quantity too.

State of marine biota in the water area of the Muchke Bay’s Coal Terminal of the Tatar Strait

An analysis of the species composition of phytoplankton and ichthyoplankton was carried out for the first time in the port water area of the Muchke Bay (Tatar Strait) in autumn. The species composition, distribution features and structure of macrozoobenthos were considered. Phytoplankton density is evenly distributed in the study area. The density of diatoms reached 97 % of the total phytoplankton density, and the biomass was 99 %. The microalgae Sceletonema costatum (Greville) Cleve, 1873 and Cylindrotheca closterium (Ehrenberg) Reimann & J.C.Lewin, 1964, species that live in polluted waters, were discovered. The development of phytoplankton in the autumn period was active, but the peak of flowering was not observed. Ichthyoplankton in October 2017 is represented by live eggs of Limanda sakhalinensis (Schmidt, 1904) (8 ind./m3), in September 2018 - by the larvae of Hexagrammos stelleri Tilesius, 1810 (0.003-0.056 ind./m3) and H. octogrammus (Pallas, 1814) (0.01-0.077 ind./m3). Up to 85 representatives of macrozoobenthos were registered from the research area, including 40 species of Polychaeta, 19 ones of Crustacea, 16 species of Mollusca, 5 ones of Echinodermata and 5 species of other fauna groups. After dredging, a decrease in the species diversity of phytoplankton, ichthyoplankton and macrozoobenthos was found in the samples.

Seasonal Species Diversity and Dominance of Phytoplankton in Different types of tropical Domestic Sewage Oxidation Ponds

Planktons are small microscopic organisms, comprising diatoms and algae, which form the basis of primary production and the zooplankton, which are mainly crustaceans, rotifers and larval stages of larger animals. Both are the bio-indicators of a water body, constituting the main food for the carnivorous and omnivorous fishes in any aquatic ecosystem. In the present study, the species diversity, and their abundance with a total and average population of various species of phytoplankton have been studied in the primary and secondary domestic oxidation ponds along with a freshwater control pond situated at Shahpura. Bhopal, Madhya Pradesh, India. Physicochemical parameters like light penetration, water temperature, pH and DO were also analyzed along with the phytoplankton population in both types of ponds to assess their impacts. The samples were collected and identified using standard methods. The results revealed that the phytoplankton groups like Chlorophyceae, Bacillariophyceae, Cyanophyceae and Euglenophyceae were dominantly found in the sewage oxidation ponds along with about 20 species of phytoplankton in varying population densities in different seasons. A similar analysis was done in a freshwater control normal pond for comparison. Physicochemical parameters in these secondary sewage oxidation ponds with a high nutrient load were found to be highly favourable for the growth of the plankton species. A comparatively low number of phytoplankton was recorded in the freshwater control pond, which was highly deficient in nutrients.

AI facilitated fluoro-electrochemical phytoplankton classification.

Marine phytoplankton is extremely diverse. Counting and characterising phytoplankton is essential for understanding climate change and ocean health not least since phytoplankton extensively biomineralize carbon dioxide whilst generating 50% of the planet's oxygen. We report the use of fluoro-electrochemical microscopy to distinguish different taxonomies of phytoplankton by the quenching of their chlorophyll-a fluorescence using chemical species oxidatively electrogenerated in situ in seawater. The rate of chlorophyll-a quenching of each cell is characteristic of the species-specific structural composition and cellular content. But with increasing diversity and extent of phytoplankton species under study, human interpretation and distinction of the resulting fluorescence transients becomes increasingly and prohibitively difficult. Thus, we further report a neural network to analyse these fluorescence transients, with an accuracy >95% classifying 29 phytoplankton strains to their taxonomic orders. This method transcends the state-of-the-art. The success of the fluoro-electrochemical microscopy combined with AI provides a novel, flexible and highly granular solution to phytoplankton classification and is adaptable for autonomous ocean monitoring.

Cypermethrin insecticide residue, water quality and phytoplankton diversity in the lychee plantation catchment area

<abstract> <p>Lychee plantation areas are typically located at varying elevations on mountains to ensure proper drainage. This placement has direct effects on stream and river water flows and consequently influences pesticide residue, water quality and aquatic biodiversity. This research aims to examine the relationships between cypermethrin residue, water quality and phytoplankton diversity in the lychee plantation catchment area in Phayao Province, Thailand, from January to May 2022. The study area was divided into six sampling sites. Water samples were collected for the investigation of cypermethrin residual, physicochemical and biological water quality parameters. The water quality index was used as an overall measurement of water quality. The study also examined the diversity of phytoplankton species and the relationship among cypermethrin residue, water quality and phytoplankton diversity were studied using canonical correspondence analysis. The findings revealed an increasing trend of cypermethrin residue, with the maximum concentration reaching 29.43 mg/L in March. The trend of decreasing water quality scores from Station S1 to Station S5 indicated the influence of land use changes and human activities, especially in the community area (S5), which was characterized by deterioration of water quality. A total of 174 phytoplankton species were categorized into 5 divisions, with Chlorophyta accounting for 61.49% of the total, followed by Bacillariophyta (28.16%) and Cyanophyta (6.32%). The highest Shannon's diversity index and evenness were observed at Stations S3 and S4, respectively. The canonical correspondence analysis revealed an interesting relationship among cypermethrin residue, ammonia nitrogen, chlorophyll a and three algal species: <italic>Pediastrum simplex</italic> var. <italic>echinulatum</italic>, <italic>Pediastrum duplex</italic> var. <italic>duplex</italic> and <italic>Scenedesmus acutus</italic> at Station S3. This research implies that pesticide residue and water quality have a direct impact on phytoplankton distribution, illustrating the environmental challenges that occur in various geographical areas. This information can be applied to assist in the development of future sustainable land use management initiatives.</p> </abstract>

The Species Structure of Plankton Communities as a Response to Changes in the Trophic Gradient of the Mouth Areas of Large Tributaries to a Lowland Reservoir

The mouth areas of large rivers can serve as a good model of heterogeneity sites with a pronounced trophic gradient to assess the impact of the degree of eutrophication on different plankton communities. The aim of this research was to identify the possible response of the diversity indicators of phyto- and zooplankton communities to trophic gradients in the mouth area of two large tributaries of the reservoir, formed in the Middle Volga River (Russia). Both linear regression models and canonical correlation analysis (CCA) were used to assess the role of abiotic and biotic predictors in the structural organization of plankton communities and to assess the changes in the parameters of the species plankton community structure in the trophic gradient. It was found that the species diversity (Adjusted R2 = 0.116) and evenness (Adjusted R2 = 0.114) of phytoplankton significantly decreased with an increase in the degree of eutrophication, while the species diversity (Adjusted R2 = 0.059) and evenness (Adjusted R2 = 0.073) of zooplankton increased. According to the CCA models, electrical conductivity (EC) explained the largest proportion of the observed dispersion. The Trophic State Index (TSI) explained 3.0% of the total variance in the phytoplankton community species structure and 7.8% in the zooplankton one. The variation in phyto- and zooplankton dominant complexes generally corresponded to the well-known patterns of plankton species succession in the gradient of trophic conditions and can be considered as a classic manifestation of the cascade effect in the food chains of freshwater plankton communities. Our results highlight the necessity of studying the mouth river areas, as well as applying an integrated approach to investigating the response of plankton communities to eutrophication processes of continental water bodies.

Species Richness, Diversity and Distribution of Phytoplankton in Fertilised Ponds of the Western Highlands Agro-Ecological Zone of Cameroon

In developing countries, advanced aquaculture techniques are still at the embryonic stage. This study was carried out from January to December 2021 in the ponds of the West Cameroon Region and at the Ichthyology and Applied Hydrobiology Research Unit of the University of Dschang with the aim of contributing to a better understanding of species richness and distribution of phytoplankton populations in fertilised ponds. For this purpose, a total of fifteen (15) ponds including 03 in Bamendou (fertilised with cow dung), four in Batié (two fertilised with pig manure and two with wheat bran), one in Dschang (fertilised with chicken manure), four in Fokoué (two fertilised with pig manure and two unfertilised), and three in Foumbot (fertilised with cow dung), were assessed. These ponds were chosen based on the availability of fish farmers and the type of fertiliser administered. Together with water physicochemical properties measurement, phytoplankton sampling was done between 6 a.m. and 8 a.m. on a monthly basis. The results showed that phytoplankton species and genera richness was higher in unfertilised ponds in Fokoué ponds and in animal feed enriched ponds in Batié, respectively. However, the highest family richness was obtained in Dschang receiving chicken manure with a percentage of 88.8% of the total family richness. The species Microcystis aeroginosa exhibited the highest species frequency (57%) out of all the species recorded in the ponds of Batié fertilised with pig manure. The lowest Shannon-Weaver diversity indices and Piélou evenness indices were recorded in the Fokoué ponds independent of the type of fertiliser, and in the Dschang ponds receiving chicken manure. The outputs of this work are better proposals for the production of phytophagous or bulldozer fish, such as carp, in relation to the site and the type of fertilisers in the Western highlands agroecological zone of Cameroon in particular and the world in general.

Летние планктонные сообщества реки Северной Двины и ее притоков

The work is a part of a comprehensive study of the rivers of the south-east of the Arkhangelsk region, carried out with the aim of developing aquaculture in inland waters. Qualitative and quantitative characteristics for the plankton communities state of the Northern Dvina River such as species composition, abundance, and biomass were obtained in the summer period of 2021. For tributaries these characteristics were obtained for the first time. The species diversity of phytoplankton and the saprobiological state of waters were assessed using indices. An assessment of the watercourses trophicity was carried out. 133 taxa of microalgae from eight systematic divisions, and nine zooplankter species of three taxonomic groups have been identified. The basis of the algoflora has been established to be diatoms, green algae, and cyanobacteria. Zooplankton communities were characterized as cladocerne-rotifers, with a significant predominance of cladocerans. The data obtained can be used for ecological monitoring of the region aquatic ecosystems, for assessing the fish productivity of water bodies, and calculating the damage to aquatic biological resources from economic activity.

Seawater quality and diversity of phytoplankton species in the waters of the North Coast of Jakarta

The North Coast of Jakarta is a strategic area to support the economy of the DKI Jakarta Province and as a place to live for organisms, one of which is phytoplankton. Phytoplankton is a primary producer in aquatic ecosystems that have an essential role in maintaining aquatic ecosystems and as an indicator of water quality. This study aims to determine the quality of seawater (turbidity, TSS, BOD, Phosphate, and Nitrate) and the diversity of species (H') of phytoplankton in the waters of the North Coast of Jakarta around the reclamation islands C and D from 2006 to 2021. Types of data used in this study is secondary data from Environmental Impact Analysis (ANDAL) documents and reports on the implementation of the Environmental Management Plan and Environmental Monitoring Plan for Reclamation and Development on Islands C and D. Concentrations of turbidity, TSS, BOD, phosphate, and nitrate in coastal waters North of Jakarta around the reclamation islands C and D are fluctuation and several sampling times exceed the quality standard. The species diversity index (H') of phytoplankton in the coastal waters of North Jakarta around the reclamation islands C and D is dominantly included in the criteria for community stability in stable conditions (H 3). Based on the partial correlation test, phosphate with the diversity of phytoplankton species in the waters of the North Coast of Jakarta around reclamation island C and D had a significant relationship (P 0.05).

Phytoplankton Community in Relation to Environmental Variables in the Tidal Mangrove Creeks of the Pasur River Estuary, Bangladesh

The Pasur River estuary (PRE) provides vital fishery resources and supports millions of livelihoods in the southwestern coastal region of Bangladesh. Our research focused on phytoplankton community assemblages, alpha diversity indices, and the seasonal succession of major phytoplankton species in relation to physicochemical parameters in the tidal mangrove creeks of the Pasur River estuary. Spatial and temporal variations were assessed by water sampling at 17 stations in the study area from January to December 2019. The mean salinity level in the tidal mangrove creeks of the PRE was significantly (p < 0.05) higher during the dry season than during the wet season. Spatially, no significant variation (p > 0.05) was observed in the dissolved inorganic nitrogen and dissolved inorganic phosphorus between PRE and mangrove creeks, but temporally, the variables varied significantly (p < 0.05). Spatially, no significant variation (p > 0.05) was observed in the alpha diversity of the phytoplankton community but significantly (p < 0.05) varied temporally. Blue-green algae became dominant in the oligohaline conditions during the wet season, while diatoms were dominant during the dry season which severely depleted dissolved silica. In terms of phytoplankton species diversity, our study classifies the study areas as highly diversified zones. Phytoplankton succession from diatoms (dry season) to blue-green algae (wet season) is attributed to the changes in the physicochemical and nutrient parameters depending on seasonal environmental parameter fluctuations. This study illustrated that phytoplankton diversity and density varied with the degrees of habitat and seasonal changes, implying the potential impacts of anthropogenic activities and natural causes on their community structure in tropical estuaries and mangrove creeks.

Keragaman Plankton di Sungai

This study aims to determine plankton diversity in the Aek Pala River, Labuhanbatu Regency. The method used is descriptive observative. Sampling was done by filtering 10 L of water using a plankton net. The results showed that there were 15 genera of plankton in Aek Pala waters, including 10 types of phytoplankton and 5 types of zooplankton. The most abundant diversity of phytoplankton species found was in the class Chlorophyceae, which was 75% (7 species). In contrast, the highest diversity of zooplankton species is from the class Crustacea (3 species). In addition, the physical and chemical parameters of the waters show that Aek Pala waters are very good for supporting plankton life. In conclusion, the diversity of plankton species obtained included phytoplankton (classes Chlorophyceae, Bacillariophyceae and Dinophyceae) and zooplankton (classes Crustacea and Rotifera). The abundance of plankton found categorizes that the river waters have moderate fertility. 
 Keywords: Diversity, Plankton, Zooplankton, Phytoplankton and Aek Pala River

Phytoplankton Groups in the Estuarine Mangrove Creeks of Edakochi (Kerala), Southwest Coast of India: A Preliminary Study

The present work focused on the ecological studies in the mangroves of the Edakochi region, Kerala (India)with special reference to phytoplankton groups. This wetland is situated on the banks of Vembanad Lake,the largest Ramsar site of Kerala. Sampling was carried out from February to June 2017. 5 true mangrovespecies and 2 semi- mangrove species were noted from the Edakochi region. A total of 25 phytoplanktonspecies were recorded from different stations comprising 15 species of Bacillariophyceae, 7 species ofDinophyceae, 1 species of Cyanophyceae, 1 species of Chlorophyceae and 1 species of Ciliateae. In eachstation the species composition was found in an order of Bacillariophyceae > Dinophyceae >Cyanophyceae> Chlorophyceae >Ciliatae. Bacillariophyceae contributed 60% of the species, whereas Dinophyceaecontributed 28%. Cyanophyceae, Chlorophyceae and Ciliateae contributed 4% each. The highest numberof species (19) was recorded during March and the highest cell density was recorded during April (1143/l). The lowest cell density was recorded in June (844/l). From the study results, it was noted that the highestnumber of species in March was due to the favorably increased salinity. The shift in the salinity regime maybe the reason for the lowest number of species in June. Alternation in species diversity influences variousecosystem phenomenon, such as nutrient retention, primary productivity and vegetation dynamics. Thestudy findings depict good species diversity of phytoplankton in the Edakochi mangrove ecosystem.

Species, taxonomic and ecological diversity of phytoplankton of the Kiliya Danube delta

An integral component of the biota of aquatic ecosystems is phytoplankton, which plays a fundamental role in the formation of the autotrophic link. The Danube delta is characterized by unique biotopes, which are characterized by a high diversity of species. Phytoplankton is an indicator of the quality of the aquatic environment and is a convenient object for research, as it can quickly respond to changes in the ecosystem. Phytoplankton species diversity of the Kiliya Danube Delta in the summer of 2019 includes 158 species and intraspecific taxa belonging to 8 divisions. The most numerous are the division Bacillariophyta (52 intraspecific taxons) and Chlorophyta (45 intraspecific taxons); orders Sphaeropleales (24), Naviculales (16), Euglenida (15), Chlorellales (13); families: Euglenidae (9), Scenedesmaceae (9), Naviculaceae (8), Selenastraceae (7), and genera Nitzschia (6), Navicula (5), Monoraphidium (5), Trachelomonas (5), Lepocinclis (5). The phototrophic link is formed mainly by diatoms and green phytoplankton planktonic and planktonic-benthic forms and indicates a dynamic hydrological regime of the object. According to saprobic species indicators, the diversity is dominated by β-saprobic (46%) and oligosaprobic (28%) forms. The water of the Kiliya Danube delta corresponds to class III in terms of organic pollution. water quality, which is characterized as "moderately polluted" and refers to β-saprobic waters. To determine the similarity of the floristic spectrum presented in different sampling locations, Sorensen coefficients in the range from 0.10 to 0.46 were calculated. types of diversity, in terms of amplitude, the stations on the Danube River (Reni, port) and the Kiliya delta (below the sea station) are most similar to each other, other areas are less similar to each other. It was found that, based on the similarity of the floristic spectrum presented in the samples, the Sorensen coefficients are quite low, and it is justified by the geographical location of the studied object, the dynamics of its hydrological regime, and different environmental conditions. The phytoplankton of the Kiliya Danube delta has a wide spectrum of species diversity relative to its spatial distribution.

Phytoplankton, with emphasis on potentially toxic cyanobacteria, from Amor Island, Alter do Chão (Santarém, Pará, Brazil)

Amor Island (Alter do Chão, Santarém, Pará, Brazil) is considered a region of great natural beauty and a national and international tourist attraction. The aim of this study was to determine the composition and density of the phytoplankton of the Amor Island, with emphasis on heterocytous cyanobacteria. Water samples for phytoplankton were collected and analyzed at seven points in October 2021. Filaments of heterocytous cyanobacteria were cultured and analyzed, measuring the cells of the first 30 trichomes. The abundance, diversity and evenness of phytoplankton species were calculated and balneability of beach in relation to algal blooms was evaluated. 106 generic and infrageneric taxa were identified, highlighting the Chlorophyta. Phytoplankton density was higher at Verde Lake (145.6 ± 22.0 org.L-1), diversity and evenness were higher at point 03 (Lake Verde) with 3.0 bits.cell-1 and 0.47, respectively. The most abundant species were: Aphanothece minutissima, Ankistrodesmus sp., Aphanothece sp., Aphanizomenon sp., Mougeotia sp., Merismopedia sp. and Quadrigula sp. The average density of cyanobacteria was higher in the Tapajós River (517.0 cell.mL-1). No algal and cyanobacterial blooms were identified, indicating water appropriate for bathing. Through morphological and morphometric description, the cultivated species were identified as Aphanizomenon gracile and Cylindrospermopsis/Raphidiopsis raciborskii, cited among the cyanobacteria with the highest occurrence of toxic blooms in the world. The region deserves phytoplankton monitoring studies, due to reports of cyanobacterial blooms, and greater knowledge of its planktonic biodiversity, since it is a threatened region.

Chlorine Concentration and Phytoplankton Diversity in the Streams around Tondano Watershed, North Sulawesi, Indonesia

The use of chlorine in agriculture and settlements increases and impacts surrounding waters, such as watersheds: The land area is a unit with rivers and tributaries that function to accommodate, store and distribute water from rainfall to the sea naturally. The environmental condition of the Tondano watershed is important to study in terms of chlorine distribution, considering that residential and agricultural activities in the watershed can cause residues in the aquatic environment, which harm the environment, especially phytoplankton. This study aims to examine the concentration of chlorine and its impact on the phytoplankton diversity in the Tondano watershed, North Sulawesi, Indonesia. Using the composite method, water quality sampling to calculate chlorine concentration was carried out at 17 river locations using the composite method, while six river stations represented phytoplankton sampling. Chlorine concentration was measured using UV-VIS spectrophotometry, while plankton sampling used a plankton net with a mesh size of 40 µm and a net mouth diameter of 20 cm. The results show that the highest chlorine concentration was found in Tondano Hilir River (0.05 mg/L), followed by the Kakas River downstream (0.04 mg/L). Chlorine concentration distribution in other rivers has the same concentration (0.03 mg/L). Quality standard Chlorine according to Government Regulation number 22/2021 Appendix VI Class II is 0,03 mg/L. The highest number of species and index of phytoplankton species diversity was found in the Hulu Panasen River, while the highest species abundance was found in the Tondano River downstream. The correlation analysis of species diversity index with chlorine concentration did not show a significant relationship with the diversity of phytoplankton, but aquatic ecosystems have experienced moderate ecological pressure.

Phytoplankton Species Diversity Patterns and Associated Driving Factors in China’s Jiulong River Estuary: Roles That Nutrients and Nutrient Ratios Play

Understanding diversity patterns and associated driving factors are the critical topics in macroecology and conservation biology. Phytoplankton are highly susceptible to environmental changes in estuaries, particularly eutrophication. This study examined phytoplankton alpha and beta diversity using investigation data in May (springtime), August (summer) and November (autumn) 2009 in China’s Jiulong River estuary, where it was easily polluted because of considerable discharge from a highly dense human population and low self-purification capacity with its limited river basin area, potentially resulting in eutrophication and then influencing phytoplankton diversity. Potential influencing factors were also explored, including dissolved oxygen, salinity, nutrients, nutrient ratios, geographic and hydrologic distance, and so on. The results indicated that Shannon’s index (H’) and Pielou’s index (J) decreased from the estuary’s upper to middle and then increased from middle to lower reaches, Simpson’s (D) observed the opposite trend and species number (S) gradually increased from the estuary’s upper to lower reaches. For beta diversity, all the indices showed a gradual decrease trend from the estuary’s upper to lower reaches, where also, turnover dominated beta diversity for all seasons. It is noteworthy that the significant roles that nutrients and nutrient ratios played in shaping phytoplankton diversity patterns and the nutrient balance were characterized by excess nitrogen (N) and silicon (Si) and limited phosphorus (P), which could potentially cause diatom blooms. Findings also showed that decreasing Si concentrations can help to reduce overall pollution levels as well as the restoration of the estuary’s ecosystem better than just reducing N alone. Accordingly, this study advocates for the protection of the entire estuary system with particular emphasis on its upper reaches. Moreover, greater attention should also be paid to impacts associated with N input and nutrient ratio trade-offs to the prospective watershed management of this estuary. This study provides a practical approach to explore estuarine diversity in a comprehensive way, which can inform effective biodiversity conservation and also be applied to other marine ecosystems to better guide sustainable management and conservation practices.

Responses of Hippopotamus amphibius to environmental changes at Bui National Park, Ghana

Many researchers have adopted the use of indicator species to detect changes in the environment and predict future ecological modifications. Irrespective of the popularity of indicator species concept among scientists in recent times, there is less studies on the use of mega semi-aquatic mammals as indicator species, especially in Africa. This study determined the ecological role of Hippopotamus amphibius and how the mammal respond to environmental changes in an aquatic ecosystem, focusing on changes in biological diversity (fish and phytoplankton) and environmental factors (temperature, pH, dissolved oxygen, conductivity, total dissolved solids, hydrogen isotope, and oxygen isotope) by comparing pools harboring H. amphibius and pools without H. amphibius at the Bui National Park, Ghana. The results show that H. amphibius play an important ecological role by indicating high productivity in aquatic ecosystem and serving as influencers of the aquatic food web at Bui National Park. The results found significantly higher concentrations of dissolved oxygen in H. amphibius pools than pools without H. amphibius. Significantly higher diversity of fish and phytoplankton species were recorded in pools with H. amphibius. Common fish species identified during this study include, Oreohromis niloticus, Labeo coubie, Alestes dentex and Labeo senegalensis. Phytoplankton communities were dominated by Chlorophyceae (37.26%), Cyanophyceae (25.21%), and Bacillariophyceae (21.53%). The study results also showed that H. amphibius are sensitive to changes in depth of water, preferring areas with shallow pools. Managerial options for H. amphibius populations require strong support because of their socio-ecological benefits including potential ecosystem effects, increasing fishing and tourism value at the Bui National Park.

Phytoplankton Community as A Bioindicator for Water Quality of Sumi Dam, Bima Regency

The waters of the Sumi dam have an important role in accordance with the purpose of its construction. Therefore, monitoring of water quality becomes necessary because good water quality is an important requirement for every organism. This study aims to examine the water quality of the Sumi dam based on the community and species diversity of phytoplankton. The sampling location was determined based on the purposive sampling method. Water samples were taken in April 2021 using a 20 micron plankton net and preserved with formalin at a concentration of 4% preservation. The results showed that the identified phytoplankton community in the Sumi Dam consisted of 80 species and 13 classes. The index value of the diversity of phytoplankton species in the Sumi dam is high. Based on the index value of the diversity of phytoplankton species as a bioindicator, the waters of the Sumi dam are included in the unpolluted category.

Таксономический состав и численность планктонных водорослей в водах Западной Антарктики (февраль–март 2020 г.)

Diversity, quantitative development and distribution of phytoplankton species were investigated. The study area included southeastern part of the Ross Sea (near Roosevelt Island) (station 3), transect 1 along the 156°W (Ross Sea at Cape Colbeck), near Russkaya station (transect 2) along the 138°W and the Bransfield Strait (transect 3) in February-March 2020, based on the data of 65th Russian Antarctic Expedition. 49 algae taxa from 7 divisions with a predominance of diatoms were identified in the phytoplankton. The spatial distribution of phytoplankton was characterized by heterogeneity which is associated with currents in the study areas, ice conditions, climatic and thermohaline factors. Development of diatoms is typical to the entire studied area. The dominant species (more than 10% of the algae population) were representatives of the genera Fragilariopsis, Chaetoceros, Actinocyclus, Corethron and Phaeocystis. The highest phytoplankton abundance (up to 264×103 cells/l) were obtained for transect 2 stations.

Abundance and diversity of phytoplankton at sekotong bay waters Western Lombok

Phytoplankton is one of the important components in aquatic ecosystems. This organism plays an important role as a primary producer to support the life of the tropics above it. The purposes of this study were to reveal the abundance and diversity of phytoplankton species in the waters of Sekotong Bay, West Lombok. Sampling were conducted in July 2018 at 8 stations using plankton net and then observed at the Laboratory. The results of the abundance calculations show a varied pattern at each observation station. The highest abundance was found at station 8 (9,060 ind/L) followed by station 6 (8,300 ind/L), station 7 (6,490 ind/L), station 4 (4,440 ind/L), station 3 (3,980 ind/L) , station 5 (2,820 ind/L), station 2 (2,460 ind/L) and station 1 (2,440 ind/L). The Shannon - Wiener Species diversity Index also shows diverse patterns at each station. Station 7 has the highest diversity index value (H′ = 3.55), followed by station 6 (H′ = 3.46), station 8 (H′ = 3.18), station 1 (H′ = 2.72) , station 2 (H′ = 2.69), station 5 (H′ = 2.67), station 4 (H′ = 2.33) and station 3 (H′ = 2.26). Species dominance index at all stations at low category with the highest dominance found at station 3 (D = 0.19), followed by station 4 (D = 0.18), station 2 (D = 0.09), station 5 (D = 0, 09), station 1 (D = 0.08), station 8 (D = 0.06), station 6 (D = 0.05) and station 7 (D = 0.04). Species Evennes index (E) values ranged from 0.71 to 0.88, indicating that the number of individual species was relatively the same and the ecosystem was in relatively good condition. The analysis showed that the spatial pattern of abundance and diversity of phytoplankton species in Sekotong Bay was related to the distance from the estuary.