Phytoplankton Classes Research Articles

Data collation for climate-cooling gas dimethylsulfide in Antarctic snow, sea ice and underlying seawater

Dimethylsulfide (DMS) is a climatically active volatile sulfur compound found in Earth’s oceans and atmosphere that plays an important role in cloud formation. DMS originates from its precursor dimethylsulfoniopropionate (DMSP), which is produced by several classes of phytoplankton. Concentrations of DMS and DMSP in Antarctic sea ice, snow and underlying seawater are not well documented and there is currently no dataset available to find the existing data. The purpose of this project was to compile historical measurements into a publicly available dataset. A total of 220 samples collected since 1992 were compiled using the Antarctic Sea ice Processes and Climate program template, in accordance with the existing datasets for chlorophyll-a, macronutrients, and dissolved iron. Analyses performed on the completed DMS dataset showed that the spatial and temporal coverages are limited; there are barely any measurements in autumn and winter, nor in the Amundsen or Ross seas. These findings provide a basis for future sampling efforts in the Antarctic region.

Pollution and the abundance of plankton in Rangkui River in Bangka Island

Land use and activity around the Rangkui Watershed affect water quality, and plankton have been studied to help manage the river's water quality. In the 2017 dry season, six station points representing land use functions from upstream to downstream were studied. Surface water sampling was carried out during the day with three replicates. Pollution around the Rangkui Watershed affected plankton abundance. Based on saprobity and physicochemical readings, the pollution level ranged from light upstream to heavy downstream. This study found 15 species from 15 families from six phytoplankton classes, that is, Bacillariophyceae, Chlorophyceae, Euglenophyceae, Cyanophyceae, Cryptophyceae, Dinophyceae, and 2 species of zooplankton Eurotatoria, and Branchiopoda. The highest total abundance of phytoplankton and zooplankton was observed upstream of Station 1 (721 ind/L) and gradually decreased downstream, with the exception of the absence of plankton at Station 3. Nitrate had a positive correlation with phytoplankton at different correlation levels, whereas other abiotic environments responded differently to phytoplankton and zooplankton. The water quality is highest upstream, where there are pepper plantations, and gradually decreases as it flows downstream. The station near tin mining activities was the most polluted.

Analisis Kelimpahan Fitoplankton dan Zooplankton di Sungai Batang Hari di Kabupaten Tebo

The aim of this research is to analyze the structure of plankton abundance and water quality in the Batang Hari River in Tebo Regency. The research method used was purposive sampling at 3 (three) points on the Batang Hari River during February - July 2024. The research results found 3 classes of Phytoplankton, namely: Bacillariophyceae, Chlorophyceae, and Cyanophyceae as well as 1 species of Zooplankton (Ciliata). This research also found the Shannon-Wiener diversity index (H') between 1.555 and 1.559; This shows the moderate stability of the plankton community and is supported by a water temperature of 28°C and adequate phosphate and nitrate content.

Comparison of Phytoplankton Composition and Abundance (River, Estuary dan Coast) as Potential Water Contamination Bio-Indicators in Tallo Watershed Area

This study aims to compare phytoplankton composition and abundance in the Tallo watershed area, evaluate its ecological factors and water quality, and their correlation to particular types of water contamination. The study was performed from June to August 2021 at three stations in the Tallo watershed, including the river (1), estuary (2), and coast (3). The results suggested that the ecological parameters were still within the tolerable limit for the organisms to live. 4 classes of phytoplankton found in the Tallo watershed included Bacillariophyceae, Cyanophyceae, Dinophyceae, and Chlorophyceae, with a total of 15 genera. No Dinophyceae was found in the river during the high and low tides and there were 9 genera found during the high tide and 10 genera found during the low tide. As many as 3 classes with 12 genera were found in the estuary during the high tide, and 4 classes with 12 genera were found during the low tide. No Chlorophyceae was found on the coast during both the low and high tides. A total of 10 genera were found during the high tide and 9 genera were found during the low tide. Analysis of variance indicated that Phytoplankton Composition there is a difference in phytoplankton abundance in 3 habitats. Phytoplankton abundance on the coast was the highest, followed by the estuary and the river (coast > estuary > river). From the abundance and the composition of phytoplankton in 3 habitats, there was a strong indication of inorganic nitrogen, heavy metal, and microplastic contamination that occurred in the Tallo watershed.

Exploring the interplay between phytoplankton taxonomy, pigments, and optical properties in Ratnagiri coastal waters using a multi-parameter approach

This study presents a comprehensive analysis of phytoplankton diversity and optical properties in the coastal waters of Ratnagiri, India. Ratnagiri, located on the southern coast of Maharashtra, is one of the major centre for fishing activities in India as well as a developing hub for industrial activities. Given its ecological significance and the pressures it faces, the coastal waters of Ratnagiri present a valuable case for studying phytoplankton dynamics and their light absorption properties. We integrated parameters like phytoplankton taxonomy, pigment composition, Coloured Dissolved Organic Matter (CDOM), and phytoplankton absorption characteristics to give a comprehensive view of the phytoplankton community and its optical environment. Phytoplankton samples from Ratnagiri were analyzed with microscopy and high-performance liquid chromatography (HPLC) for taxonomy and pigment profiling, while CDOM and absorption properties were measured using spectrophotometry. Our findings reveal more or less spatial uniformity in phytoplankton composition (Pielou's Evenness Index (J’) ranged between 0.84 and 0.9), with significant diversity (Shannon Diversity Index (H’) ranged from 3.7 to 4.19) within the phytoplankton community. Pigment analysis revealed key marker pigments associated with various phytoplankton classes including bacillariophytes (diatoms), chlorophytes, cyanophytes, haptophytes and cryptophytes, providing insights into community structure. Concurrently, CDOM absorption coefficient (aCDOM (440)) that ranged between 0.08 and 0.3 m−1 indicated varying levels of dissolved organic matter, influencing light absorption and availability within the water column. The phytoplankton absorption data highlighted the specific wavelengths most affected by phytoplankton presence, notably those contributed by diatoms and cyanophytes, providing insights into the optical properties of Ratnagiri's coastal waters. This integrative approach underscores the importance of considering multiple parameters to accurately assess phytoplankton dynamics and their impact on the aquatic environment. The results contribute to a better understanding of the ecological processes governing coastal waters in Ratnagiri and offer valuable information for future monitoring and management efforts.

Temporal changes of phytoplankton-derived sterols in suspended particulate matter and their implications as biomarkers for phytoplankton abundance in northern Patagonia, Reloncaví Estuarine System (RES), Chile

The Northern Patagonia coast, characterized by an intricate interaction among terrestrial and marine systems such as Reloncaví Estuarine System (RES), present highly productive marine and aquaculture activities, having a significant socio-economic importance in Chile. Understanding the composition of Organic Matter (OM) in aquatic ecosystems is crucial for elucidating biogeochemical processes, and the use of lipid biomarkers, has proven valuable in identifying OM sources. This study investigates the relationship between phytoplankton biomass indicators, including phytoplankton abundance, chlorophyll-a, and sterol molecules synthesized in high percentages by phytoplankton cells, also known as phytoplankton-derived sterols at the RES. The RES encompasses the Reloncaví Fjord (RF) and the Reloncaví Sound (RS) and exhibits a high influenced by oceanic waters and freshwater discharge from rivers Spatio-temporal sampling was conducted during the austral spring, summer and winter expeditions of 2018 and 2019, at two sites in RS and RF mouth (RFm). Our findings reveal higher sterol concentration at RFm than RS. Notably, high sterol concentrations during austral summer season coinciding with increased phytoplankton abundances. Furthermore, higher concentrations of terrestrial-derived sterols such as β-sitosterol (C29Δ5) and stigmasterol (C29Δ5,22), at RFm site suggested an input of OM from the inner RF. Phytoplankton-derived sterols such as 24-methylenecholesterol (C28Δ5,24(28)) provide a reliable estimate of total diatom abundance at both sites (RFm and RS), though they showed a lower relationship with taxonomic subgroups and phytoplankton classes in our study area. Hence, phytoplankton-derived sterols can be considered reliable diatom biomarkers, particularly in the RS, where the primary source of OM is predominantly marine, and even with high sterol degradation values at RES. Our study highlights the importance of interpreting changes in sterol abundances as phytoplankton community shifts. To avoid misinterpretation, it is essential to incorporate direct phytoplankton counts in elucidating the complex biosynthetic sources of sterols within the water column.

The role of predation and pesticides in shaping phytoplankton dynamics in a short microcosms experiment.

Aquatic organisms are subject to various forcing factors that affect their structure, some of which are natural, while others result from human activities, both having variable effects. This study aimed to determine the importance of a natural stressor (zooplankton) and an herbicide (atrazine) on phytoplankton density and morphological composition in a microcosm experiment. A natural phytoplankton assemblage was exposed to two zooplankton predators: a copepod (Argyrodiaptomus falcifer) and a cladoceran (Ceriodaphnia dubia), and to atrazine (27 µg L-1), in three combinations of factors (zooplankton treatments (Z), atrazine treatment (A), the combination of both (ZA)) plus a Control. The experiment lasted 48 h. Samples were taken at the beginning and the end of the experiment, and relevant limnological variables, including inorganic nutrient concentrations, were considered. Results indicated differences in phytoplankton densities when treatments were compared with Control. In this respect, Chlorophyceae, Euglenophyceae, and Bacillariophyceae exhibited more changes than other phytoplankton classes. Chlorophyceae densities tended to be higher in the Control than in the treatments; the combination of zooplankton and atrazine favored Euglenophyceae, while atrazine favored Bacillariophyceae densities. Regarding morphological groups, unicellular and small colonies (<35 µm), showed differences between the Control and particularly with Z treatment, colonial-cenobia forms were negatively affected by atrazine and silica forms were favored by both stressors combined. It is concluded that interactions among natural and anthropogenic stressors could be complex, influencing factors such as phytoplankton taxonomical affinities, morphological groups, and the nature of the stressor applied.

A Study of the Analysis of Chlorophyll-a Phytoplankton in the Tigris Rivers for Some Regions of Iraq by Using GIS Techniques

In this study, the distribution of chlorophyll-a for phytoplankton was monitored using Geographic Information System (GIS) techniques in selected regions of Iraq represented by the three governorates namely: Salah al-Din (Samarra (1), Baghdad (Al-Muthanna Bridge (2), Al-Utaifi (3), Al-Jadiriya(4), Kut (Al-Aziziyah (5), Al-Zubaydah (6), Al-Numaniyah (7), and Al-Muftah (8)) as human agricultural, and industrial activity rose in these locations. These stations, which are located along the Tigris River, were used as sites for collecting samples. The selection procedure was conducted on a monthly basis between February 2022 and January 2023. Chlorophyll-a measurements for phytoplankton throughout the sampling period varied from 3.7 to 2.59 g/L at stations. The two stations (Al-Utaifi and Al-Zubaydah) had similar values for both seasons, and the five stations in the dry season had values of less than 0.23 g/L. While phytoplankton numbers varied from 40.32 104 to 21.16 104cell/L for stations 3 and 5, respectively, they varied from 72.39 104 to 37.7 104cell/L for stations 6 and 8, respectively, throughout the wet season. In all of the stations and classes of phytoplankton, the amount of chlorophyll dye was approximately equal to the overall density of phytoplankton. The area under study’s predictive maps of chlorophyll-a analysis also revealed changes in the concentration of dye in all stations.

Long-term monitoring of water quality and phytoplankton community structure of Lake Manzala, Mediterranean Coast of Egypt

Coastal wetlands play a crucial role in supporting biodiversity, providing valuable ecosystem services, and contributing to the resilience of coastal ecosystems, making the preservation and restoration of these wetlands essential for sustainable development in coastal regions. This study focuses on Lake Manzala, a coastal wetland located on the Mediterranean Coast of Egypt, highlighting the significance of conserving and managing this unique environment. The objective of this research was to evaluate the water quality and phytoplankton structure of Lake Manzala and establish an updated long-term ecological database for the region, specifically evaluating the effectiveness of development plans that were carried out in 2017. Surface water samples were collected seasonally at eleven sites between 2010 to 2022. The findings revealed that prior to the development plans, the phytoplankton abundance in Lake Manzala exhibited high levels of eutrophication, characterized by increased abundance and species richness. The dominant phytoplankton classes in Lake Manzala were Bacillariophyceae, Chlorophyceae, and Cyanophyceae. Prior to development plans, they accounted for 46.5% and 45.0% respectively. Post-development, Bacillariophyceae increased to 62.8%, while Chlorophyceae decreased to 25.1%. Dinophyceae increased from 1.3% to 9.04%, while Cyanophyceae decreased from 6.1% to 1.6%. Based on the Trophic State Index for chlorophyll a, Lake Manzala underwent a shift from predominantly hypertrophic to eutrophic conditions. The study explored the relationship between biological factors and environmental conditions using principal component analysis, cluster analysis, and the modified water quality index (WQI). The results indicated positive signs of improvement in Lake Manzala during the post-development phase, as it transitioned from a poor to a moderate state. This research emphasizes the need for integrated land and water management approaches. By informing policy direction and development, this research underscores the importance of preserving and restoring ecosystems for the long-term well-being of both local communities and the global environment.

Nutrient Concentration, Water Brightness, Chlorophyll-a, and Phytoplankton Abundance as Indicators for Determining the Trophic Status of Lake Toba, North Sumatera - Indonesia

The purpose of this study was to investigate the water quality and phytoplankton abundance in Lake Toba to determine its trophic status. This research was conducted from January to March 2024 at four stations in Lake Toba. Water samples were taken using a UWITEC water sampler and a plankton net and brought to the laboratory for analysis. The study measured physical and chemical water quality and phytoplankton abundance. The results showed a brightness ranging between 5.8 and 6.3 meters, chlorophyll-a content &lt;10 µg/L, total nitrogen &lt;750 µg/L, and phosphorus ranging from 20 µg/L to 30 µg/L. Based on these parameters, the nutrient quality of Lake Toba was classified as mesotrophic. Phytoplankton abundance ranged from 22,514 to 33,475 individuals/L, with 33 genera identified across nine classes: Bacillariophyceae, Chlorophyceae, Cyanophyceae, Coscinodiscophyceae, Dinophyceae, Euglenida, Fragilariophyceae, Mediophyceae, and Zygnemophyceae. The diversity index (H') was 2.631 - 2.723, the uniformity index (E) was 0.828 - 0.872, and the percentage of blue-green algae was 14.75 - 20.85. Zygnemophyceae was the most dominant phytoplankton class, with Staurastrum sp. being the most prevalent species. In conclusion, Lake Toba's waters are categorized as mesotrophic based on the chemical parameters and as eutrophic based on phytoplankton abundance, indicating potential nutrient enrichment issues that warrant further investigation.

Abundant mRNA m1A modification in dinoflagellates: a new layer of gene regulation

Dinoflagellates, a class of unicellular eukaryotic phytoplankton, exhibit minimal transcriptional regulation, representing a unique model for exploring gene expression. The biosynthesis, distribution, regulation, and function of mRNA N1-methyladenosine (m1A) remain controversial due to its limited presence in typical eukaryotic mRNA. This study provides a comprehensive map of m1A in dinoflagellate mRNA and shows that m1A, rather than N6-methyladenosine (m6A), is the most prevalent internal mRNA modification in various dinoflagellate species, with an asymmetric distribution along mature transcripts. In Amphidinium carterae, we identify 6549 m1A sites characterized by a non-tRNA T-loop-like sequence motif within the transcripts of 3196 genes, many of which are involved in regulating carbon and nitrogen metabolism. Enriched within 3′UTRs, dinoflagellate mRNA m1A levels negatively correlate with translation efficiency. Nitrogen depletion further decreases mRNA m1A levels. Our data suggest that distinctive patterns of m1A modification might influence the expression of metabolism-related genes through translational control.

Research on the Relationship between Eukaryotic Phytoplankton Community Structure and Key Physiochemical Properties of Water in the Western Half of the Chaohu Lake Using High-Throughput Sequencing

Eukaryotic phytoplankton play a major role in the circulation of material and energy in a lake’s ecosystem. The acquisition of information on the eukaryotic phytoplankton community is extremely significant for handling and regulating the ecosystems of lakes. In this study, samples were collected from the western half of Chaohu Lake in the summer and winter periods. Analyses revealed that the eukaryotic phytoplankton in this region comprised 70 genera, 34 orders, and 7 phyla. There were 61 genera, 29 orders, and 7 phyla in summer, and 25 genera, 14 orders, and 5 phyla in winter. The dominant genus was Chlamydomonas of Chlorophyta in summer. In contrast, the dominant genus was Mychonastes of Chlorophyta in winter. The diversity index analysis revealed that the eukaryotic phytoplankton community exhibited greater fluctuation in the summer than in the winter. Moreover, analysis of the physiochemical properties of the water samples showed considerable spatial and temporal differences in the water quality. This paper focusses primarily on analysing the influence of the physiochemical properties of water on the eukaryotic phytoplankton community. In particular, the effects of the major physicochemical properties of water on the community evolution of eukaryotic phytoplankton classes were evaluated using the redundancy analysis method. The findings demonstrated that total phosphorus (TP), PO4−-P, NH4+-N, and total nitrogen (TN) were the primary influencing factors in summer, whereas NO3−-N, DO, and water temperature (WT) were the major influencing factors in winter. Subsequently, the Mantel test revealed that the phylum level of the eukaryotic phytoplankton community was significantly correlated with WT, DO, NH4+-N, TN, TP, and Chlorophyll a. Variance partitioning analysis indicated that seasonal factors accounted for a large proportion of the variation in the eukaryotic phytoplankton community, reaching 48.4%. Subsequently, co-occurrence network analysis demonstrated that most families of eukaryotic phytoplankton were facilitated mutually, with the proportion of promotion being 94.1%. This study provides insight into the crucial factors that influence the phytoplankton communities and a reasonable control direction for the positive evolution of the eukaryotic phytoplankton community in the western half of Chaohu Lake.

Eating Habits and Dietary Strategies of the Glass Perchlet Fish (Ambassis macracanthus) In Benoa Bay Waters, Bali in Two Different Seasons

The Benoa Bay area and its surroundings are a center of biodiversity at the ecosystem level in the southern coastal region of Bali. This area exhibits diverse ecosystems, including mangrove ecosystems, coral reefs, seagrass beds, and tidal flats. This research aims to analyze and describe the feeding ecology of Ambassis macracanthus in the waters of Benoa Bay. The study was conducted in May, at the end of the transitional season, and in July and August, during the eastern monsoon season in Benoa Bay Waters. Modified gill nets with mesh sizes of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 cm were used for capturing the fish. The fish were caught at three stations, which represented the characteristic conditions of the Benoa Bay Waters. Out of the 396 individuals caught during the study, only 100 were selected for examination. The average relative fullness gut index (RGI) of Ambassis macracanthus ranged from 0.39 to 0.67. The total Important Relative Index (IRI) value for the food of Ambassis macracanthus in Benoa Bay Waters was 951.27. Ambassis macracanthus in Benoa Bay Waters is an omnivorous species with a tendency towards herbivory, and 21 different organisms were found in its diet, including three classes of phytoplankton and three classes of zooplankton. The feeding strategy developed by Ambassis macracanthus in Benoa Bay Waters is generalist. This information about the fish can be used as a fundamental basis for managing fish in the waters of Benoa Bay.

Killing the predator: impacts of highest-predator mortality on the global-ocean ecosystem structure

Abstract. Recent meta-analyses suggest that microzooplankton biomass density scales linearly with phytoplankton biomass density, suggesting a simple, general rule may underpin trophic structure in the global ocean. Here, we use a set of highly simplified food web models, solved within a global general circulation model, to examine the core drivers of linear predator–prey scaling. We examine a parallel food chain model which assumes microzooplankton grazers feed on distinct size classes of phytoplankton and contrast this with a diamond food web model allowing shared microzooplankton predation on a range of phytoplankton size classes. Within these two contrasting model structures, we also evaluate the impact of fixed vs. density-dependent microzooplankton mortality. We find that the observed relationship between microzooplankton predators and prey can be reproduced with density-dependent mortality on the highest predator, regardless of choices made about plankton food web structure. Our findings point to the importance of parameterizing mortality of the highest predator for simple food web models to recapitulate trophic structure in the global ocean.

Evaluation of Mangrove Ecosystem Quality in Bawean Island, East Java Using Phytoplankton as Bioindicators

Graphical Abstract Highlight Research Highlights from this results research: Restoration is a method to restore degraded mangrove ecosystems The success of restoration is measured by improvements in ecosystem services such as water quality, mangrove diversity, phytoplankton community structure and diversity Phytoplankton as bioindicator of water quality Anthropogenic activities are the main factor causing degradation of mangrove ecosystems Abstract The mangrove ecosystems in Bawean Island are degraded due to anthropogenic activities and land conversion. Plantation has carried out periodic which was continued in several mangrove ecosystems. This study was conducted to evaluate the physicochemical water quality of several mangrove ecosystems in Bawean Island, and phytoplankton as bioindicators. The evaluation of mangroves in Bawean Island was carried out at 11 locations based on different naturalness and human activities surrounding. The physical and chemical parameters of water observed were air temperature, water temperature, pH, TSS, dissolved oxygen (DO), biochemical oxygen demand (BOD), salinity, conductivity, nitrate, and orthophosphate. Community structure and plankton diversity measured include the Importance Value Index (IVI), Shannon-Wiener diversity index (H'), Simpson dominance index (Id), evenness index (E), trophic diatom index (TDI), and pollution tolerant value (% PTV). The physical parameters of water chemistry show that it meets the quality standards based on Indonesian Government Regulation No. 22 of 2021 except for nitrate and orthophosphate, but it is still under plankton tolerant. A total of 63 species from 7 phytoplankton classes were found based on the importance value index. Based on the TDI index, mangrove ecosystems Sawahmulya, Sidogedungbatu, Hijau Daun, Pamona, Pasir Putih, Sungai Rujing, Bangsal, Jherat Lanjheng, and Lebak were classified as eutrophic while Pulau Cina and Dekatagung were hyper-eutrophic. Based on %PTV, the Hijau Daun mangrove is the best mangrove ecosystem while other mangroves were classified as moderate and heavily level polluted.

Local intraspecific aggregation in phytoplankton model communities: spatial scales of occurrence and implications for coexistence.

The coexistence of multiple phytoplankton species despite their reliance on similar resources is often explained with mean-field models assuming mixed populations. In reality, observations of phytoplankton indicate spatial aggregation at all scales, including at the scale of a few individuals. Local spatial aggregation can hinder competitive exclusion since individuals then interact mostly with other individuals of their own species, rather than competitors from different species. To evaluate how microscale spatial aggregation might explain phytoplankton diversity maintenance, an individual-based, multispecies representation of cells in a hydrodynamic environment is required. We formulate a three-dimensional and multispecies individual-based model of phytoplankton population dynamics at the Kolmogorov scale. The model is studied through both simulations and the derivation of spatial moment equations, in connection with point process theory. The spatial moment equations show a good match between theory and simulations. We parameterized the model based on phytoplankters' ecological and physical characteristics, for both large and small phytoplankton. Defining a zone of potential interactions as the overlap between nutrient depletion volumes, we show that local species composition-within the range of possible interactions-depends on the size class of phytoplankton. In small phytoplankton, individuals remain in mostly monospecific clusters. Spatial structure therefore favours intra- over inter-specific interactions for small phytoplankton, contributing to coexistence. Large phytoplankton cell neighbourhoods appear more mixed. Although some small-scale self-organizing spatial structure remains and could influence coexistence mechanisms, other factors may need to be explored to explain diversity maintenance in large phytoplankton.

Multiple biotic interactions establish phytoplankton community structure across environmental gradients

AbstractThe combination of taxa and size classes of phytoplankton that coexist at any location affects the structure of the marine food web and the magnitude of carbon fluxes to the deep ocean. But what controls the patterns of this community structure across environmental gradients remains unclear. Here, we focus on the North East Pacific Transition Zone, a ~ 10° region of latitude straddling warm, nutrient‐poor subtropical and cold, nutrient‐rich subpolar gyres. Data from three cruises to the region revealed intricate patterns of phytoplankton community structure: poleward increases in the number of cell size classes; increasing biomass of picoeukaryotes and diatoms; decreases in diazotrophs and Prochlorococcus; and both increases and decreases in Synechococcus. These patterns can only be partially explained by existing theories. Using data, theory, and numerical simulations, we show that the patterns of plankton distributions across the transition zone are the result of gradients in nutrient supply rates, which control a range of complex biotic interactions. We examine how interactions such as size‐specific grazing, multiple trophic strategies, shared grazing between several phytoplankton size classes and heterotrophic bacteria, and competition for multiple resources can individually explain aspects of the observed community structure. However, it is the combination of all these interactions together that is needed to explain the bulk compositional patterns in phytoplankton across the North East Pacific Transition Zone. The synthesis of multiple mechanisms is essential for us to begin to understand the shaping of community structure over large environmental gradients.

Ikan Nyalian (Barbodes binotatus Valenciennes, 1842) di Danau Tamblingan, Buleleng, Bali Dilihat dari Aspek Makanannya

Tamblingan Lake is one of four lakes in Bali which is located in Munduk Village, Banjar District, Buleleng Regency, Bali. Spotted barb (Barbodes binotatus) is a freshwater fish belonging to the Cyprinidae family found in Tamblingan Lake. Information regarding the food composition of spotted barb in Tamblingan Lake has not been carried out. This research aims to determine the food of nyalian fish by observing the composition of the type of food in the Tamblingan Lake Waters. Fish sampling was carried out in January-June 2019 using gill nets with a mesh size of 0.5; 1.0; 1.5; 2.0; 2.5; 3.0 cm with length of 300 m and height of 2 m. Fishing was carried out at five stations with different characteristics. Fish samples obtained during the research were 180 fish. The composition food of spotted barb consists of 37 types of organisms consisting of 6 classes of phytoplankton, 6 classes of zooplankton, 1 class of fungi and 1 class of aquatic plants. Most types of food organisms come from the Bacillariophyceae class, which is 16 genera. Species of Surirella sp., Navicula sp., Cymbella sp., and Pinnularia sp. is a genus of the Bacillariophyceae class which is often found every month of observation with the frequency of occurrence respectively 174, 105, 126 and 112. There was not much difference in food composition between nyalian fish in each month of observation. Spotted barb include omnivorous fish (tend to be herbivores) and classified as euryfagus.

Plankton Diversity and Hydro-biological Parameters at Wazirabad Barrage in Yamuna River

This study conducted a comprehensive investigation into the qualitative and quantitative analysis of plankton diversity and Physico-chemical water quality parameters in the Yamuna River. Samples were collected from the Wazirabad barrage from June 2022 to November 2022, revealing a diverse phytoplankton community consisting of 50 genera distributed across five major classes. The abundant classes were Bacillariophyceae, with 18 genera, followed by Chlorophyceae with 20 genera, Cyanophyceae with 9 genera, Euglenophyceae with 2 genera, and Dianophyceae represented by a single genus. The qualitative analysis uncovered a zooplankton community with 20 genera from Protozoa and Rotifera, Copepoda, and Cladocera. Protozoa were represented by two genera, Copepods exhibited eight genera, Cladocera included five genera, and Rotifera featured four genera. The most abundant class of phytoplankton is Chlorophyceae and Zooplankton is Copepods. Physico chemical water quality parameters more fluctuation during the study period. These findings offer valuable insights into the biodiversity and composition of phytoplankton and zooplankton communities in the Wazirabad Barrage ecosystem.

Diversity and abundance of phytoplankton in Bone Bay, South Sulawesi, Indonesia and its relationship with environmental variables

Abstract. Tambaru R, Burhanuddin AI, Haris A, Amran MA, Massinai A, Muhiddin AH, Yaqin K, Firman, Yuliana. 2024. Diversity and abundance of phytoplankton in Bone Bay, South Sulawesi, Indonesia and its relationship with environmental variables. Biodiversitas 25: 624-631. Ecological studies of phytoplankton have been widely conducted in various bays around the world. However, such research is still limited in Bone Bay, South Sulawesi, Indonesia. Therefore, this study aimed to investigate the diversity and abundance of phytoplankton in Bone Bay and the relationships with environmental factors. Data collection was conducted in the dry season (May to June 2023) at four stations, namely Bajoe Harbor (PB), Cappa Ujung (CU), Libureng (LB), and Tongke-Tongke (TT). At each station, seawater samples were collected and environmental variables were measured including temperature, salinity, pH, currents, and nutrients (i.e. Nitrate, Nitrite, Ammonium, Orthophosphate, and Silicate). In general, the environmental variables in the studied area were within the range of optimal condition for phytoplankton to grow and develop. There were three classes of phytoplankton recorded, namely Bacillariophyceae, Cyanophyceae, and Dinophyceae, with a total of 31 genera were identified. Chaetoceros, Thallasionema, and Rhizosolenia were the dominant genera. The average abundance of phytoplankton was significantly different among stations with the highest was found in CU and PB compared to that in LB and TT (p-value &lt;0.01). PCA analysis showed that phytoplankton abundance was related to high orthophosphate concentrations, silicate, and turbidity at the PB and CU stations, while the opposite condition occured at the LB and TT stations. Based on the diversity and abundance of phytoplankton, Bone Bay, South Sulawesi is now still in good condition, yet monitoring studies are recommended to see the changes in the future.