Bacterial and plankton communities in mariculture water sources: a case study in Nampu and Sembukan seawaters, Wonogiri, Indonesia

Seawaters in Indonesia, part of the tropical marine ecosystem, have great microbial and plankton diversity. Seawater is used as a water source for marine aquacultures, such as shrimp, milkfish, lobster, and mud crab. Sustainability of environmental resources for supporting aquaculture activities can be assessed by analyzing the actual conditions of the water source environment, including bacterial and plankton communities. However, the characteristics of bacteria and plankton communities in Indonesian seawaters have not been well documented. In this study, we investigated the bacterial and plankton communities in surface seawater from two coastal areas, i.e. Nampu and Sembukan, Wonogiri regency, Central Java, Indonesia. Bacterial diversity was analyzed using the Illumina-based high throughput sequencing with a primer set targeting the V3-V4 region of the bacterial 16S rRNA gene. Meanwhile, the plankton community (phytoplankton and zooplankton) was calculated and identified using a counting chamber method. Sequencing analysis revealed that the five dominant bacterial phyla in the two seawater samples were similar, consisting of Proteobacteria, Firmicutes, Actinobacteria, Bacteriodetes, and Cyanobacteria. Although the two sites are separated by several kilometres, the distribution of dominant bacterial phyla in both seawater samples is similar. Phytoplankton in Nampu and Sembukan were similarly dominated by Trichodesmium sp., Navicula sp., and Rhabdonema sp. Dominant zooplankton in the two sites were Euterpina, Nauplius, Oithona sp., Oncaea sp., Tigriopus sp., and Gastropoda larvae. The seawater in Nampu and Sembukan is suitable as a water source for aquaculture.

Metabarcoding Analysis of Harmful Algal Bloom Species in the Western Pacific Seamount Regions

The Western Pacific is the most oligotrophic sea on Earth, with numerous seamounts. However, the plankton diversity and biogeography of the Western Pacific in general and the seamount regions in particular remains largely unexplored. In this project, we quantitatively analyzed the composition and distribution patterns of plankton species in the Western Pacific seamount regions by applying metabarcoding analysis. We identified 4601 amplicon sequence variants (ASVs) representing 34 classes in seven protist phyla/divisions in the Western Pacific seamount regions, among which Dinoflagellata was by far the most dominant division. Among the 336 annotated phytoplankton species (including species in Dinoflagellata), we identified 36 harmful algal bloom (HAB) species, many of which displayed unique spatial distribution patterns in the Western Pacific seamount regions. This study was the first attempt in applying ASV-based metabarcoding analysis in studying phytoplankton and HAB species in the Western Pacific seamount regions, which may facilitate further research on the potential correlation between HABs in the Western Pacific seamount regions and coastal regions.

Limnochemistry and Plankton Diversity in Some High Altitude Lakes of Kashmir Himalaya

High altitude lakes (HALs) of Kashmir Himalaya are the important ecosystems in the mountain ecology of the broader Hindukush Himalayan region. This article provides a comprehensive information about the plankton (phytoplankton and periphyton) assemblages, water quality (WQ), bathymetry, morphometry, and land use land cover (LULC) of some select high altitude mountain lakes of Kashmir Himalaya. LULC analysis revealed that the catchment of the lakes spread over an area of about 16179 ha, is covered by different land cover types dominated by pastures (50.8%), followed by barren rocky (32.6%), snow and glaciers (11.9%), lakes (2.5%), forest (2%), and streams (0.2%). Bathymetric and morphometric analysis revealed that the Gangbal Lake is the deepest (84 m) and largest (162.4 ha) among the investigated lakes. The water quality index revealed that all the HALs have the excellent water quality category. Statistical analysis (Wilk’s λ) depicted that nitrate-nitrogen (NO3−-N), nitrite nitrogen (NO2−-N), ammoniacal nitrogen (NH3-N), total phosphorus (TP), and magnesium hardness (Mg-H) are responsible for major variability between all HALs sites. The cations followed the order of Ca2+ > Mg2+ > Na+ > K+ while as anions followed the order as HCO3− > Cl− > SO42−. Algal composition (phytoplankton and periphyton) assessment revealed the presence of 61 taxa belonging to Bacillariophyceae (45), Chlorophyceae (14), Cyanophyceae (1), and Xanthophyceae (1). The higher dominance of Bacillariophyceae indicates oligotrophic nature of the lakes. Canonical correspondence analysis (CCA) highlighted the role of various water quality parameters like pH, EC, and TDS on the composition of phytoplankton and periphyton species among the lakes. The present study therefore generated a baseline database for some of the HALs of Kashmir Himalaya that can act as a precursor for more research on future changes in the lake ecosystems of the region.

Study of Plankton diversity status of local habitat in eastern Uttar Pradesh

The studies included the local habitat of Lake River and ponds, which are most important, share the habitat in local flora and fauna in eastern Uttar Pradesh (U.P.) India. The study was conducted to assess the mainly phytoplankton and zooplankton status of the Ramgarh lake, Maheshra tal, and Rapti river in Gorakhpur district of Uttar Pradesh, India by examining the biological parameters. The most important planktonic group encountered in the present study was cyanophyceae and Zygnematophyceae Nostocale and Desimidiale encountered as other genera which existed in the Ramgarh lake, Maheshra tal, and Rapti river water of the habitat. The study found that the members of protozoans group animal contribute 50 percent of the total zooplankton population during the year of the study period.

Decline in plankton diversity and carbon flux with reduced sea ice extent along the Western Antarctic Peninsula

Since the middle of the past century, the Western Antarctic Peninsula has warmed rapidly with a significant loss of sea ice but the impacts on plankton biodiversity and carbon cycling remain an open question. Here, using a 5-year dataset of eukaryotic plankton DNA metabarcoding, we assess changes in biodiversity and net community production in this region. Our results show that sea-ice extent is a dominant factor influencing eukaryotic plankton community composition, biodiversity, and net community production. Species richness and evenness decline with an increase in sea surface temperature (SST). In regions with low SST and shallow mixed layers, the community was dominated by a diverse assemblage of diatoms and dinoflagellates. Conversely, less diverse plankton assemblages were observed in waters with higher SST and/or deep mixed layers when sea ice extent was lower. A genetic programming machine-learning model explained up to 80% of the net community production variability at the Western Antarctic Peninsula. Among the biological explanatory variables, the sea-ice environment associated plankton assemblage is the best predictor of net community production. We conclude that eukaryotic plankton diversity and carbon cycling at the Western Antarctic Peninsula are strongly linked to sea-ice conditions.

The diversity of plankton as bioindicators in Kakap River Estuary, West Kalimantan

Kakap River Estuary plays an essential role in the life organisms, but it is vulnerable to environmental changes and pollution caused by human activities. This study aims to assess the presence of plankton species, their abundance and diversity as aquatic ecological bio-indicators in Kakap River Estuary. Plankton and water samples were taken for three months, with a frequency of one sample per month, viz. in March, April and June 2020 from four sampling stations in Kakap River Estuary, West Kalimantan. A total of 34 species of plankton were observed from all sampling sites, and identified to belong to 18 classes. Chlorophyceae had the highest relative abundance among the phytoplanktons (40.10%), followed by Bacillariophyceae (21.86%) and Cyanophyceae (19.28%). Oscillatoria sp. and Hydrodictyon sp. were the most dominant phytoplankton species. There were 8 classes of zooplankton identified from all sampling stations throughout the research period. Hexanauplia had the highest relative abundance among the zooplanktons (36.56%) followed by Euglenophyceae (24.37%). The plankton diversity index (H ′) values ranged between 2.33 -3.11. The plankton evenness index value ranged from 0.79 to 0.89 which indicates high plankton evenness at all samping stations, and this is supported by a low dominance index value at all stations ranging from 0.06-0.16. Station 1 had high Shannon-Wienner diversity index score, while for station 2, 3, 4, their scores were in the moderate level. Overall. the diversity index of the plankton from all sampling sites indicated that the quality of the water had no pollution to light pollution level.Keywords:PhytoplanktonZooplanktonWater quality

Association of Seawater Nanoparticle Size Distribution With Diversity of Marine Plankton

Upon tangential ultrafiltration and asymmetric flow field analyses, seawater nanoparticle size distribution and the associations with the total number of bacteria and plankton diversity were evaluated. Of the nanoparticles in the Jiulong River Estuary, 79% were from 1 to 6 nm (C1). C2 (6–20 nm) was correlated with dissolved organic carbon, while C2 and C3 (>20 nm) were associated with dissolved inorganic nitrogen, suggesting that C2 and C3 were impacted by biogenic elements. The total number of bacteria was correlated with C1 and C3. The correlations of Shannon's diversity index (H′) and C3, richness (d), and C1 suggested a link of particle size with phytoplankton biodiversity. Significant correlations of the H′ of zooplankton and C3, and of Pielou's evenness index (J) and C3, suggested C3 as a primary digestion product of zooplankton. The negative correlations of nano-organic carbon (NOC) with d and J suggested NOC as a carbon source for zooplankton. Biodiversity was associated with seawater nanoparticle size distribution. Biological activities regulated the nanoparticle size distribution, which impacted the estuarine nutrient cycling, in turn affecting the stability and balance of biodiversity. Correlation analysis of the size distribution of seawater nanoparticles and the plankton diversity index provided a potential tool for evaluating ecological effects.

Plankton Community in Ogan River, Kertapati District, Palembang, South Sumatra

Research on Plankton Community in The Waters of Ogan River Kertapati District, Palembang, South Sumatra Province, has been conducted from March to April 2018. This study aimed to identify the plankton community, i.e., abundance, diversity index, dominance index, similarity index between stations, and describe pollution level conditions based on saprobic coefficient. Sampling in this study using purposive random sampling method at five observation stations with three sampling locations, respectively. The physical and chemical parameters of the waters include temperature, brightness, current speed, pH, Dissolved Oxygen (DO), nitrates, and phosphates. The composition of plankton consists of 47 Genera derived from 8 Classes, with a total abundance value in March ranging from 13-27 ind./L, and the total value of abundance in April 2018 has a range of values of 12-21 ind./L. Plankton diversity index values in about 1.87-2.98 indicate the stability of the moderate biota community. Based on the index of plankton dominance with a range of 0.05-0.21, no species dominate other species or D = 0(<0.5). In contrast, the index of plankton similarity between stations shows the communities between stations are relatively different (<50%). The water quality of the Ogan River based on saprobic coefficients is light to very light.