Average Phytoplankton Abundance Research Articles

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 <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.

Critical factors driving spatiotemporal variability in the phytoplankton community structure of the coral habitat in Dongshan Bay, China.

This study investigated the spatiotemporal distribution of the phytoplankton in the coral habitat of Dongshan Bay (China), along with critical factors affecting the distribution, during June, August, and December 2022. Phytoplankton abundance in Dongshan Bay exhibited considerably temporal variation, peaking in June 2022, gradually decreasing thereafter, and reaching its lowest point in December 2022. The abundance of bottom-layer phytoplankton consistently exceeded that of the surface layer throughout all seasons. The average phytoplankton abundance in the coral habitat of Dongshan Bay was lower than that in non-coral habitat areas. Fluctuations in the Zhangjiang River and coastal upwelling influenced the diversity and community structure of the phytoplankton. Critical factors causing spatiotemporal variability in phytoplankton community structure included nutrient concentrations and seawater temperature. Nutrients played key roles in influencing various phytoplankton groups. Dominant diatom species, such as Thalassionema nitzschioides and Thalassiosira diporocyclus, were positively correlated with ammonia nitrogen, seawater salinity, coral cover, and the number of coral species present. In winter, Calanus sinicus exhibited a negative correlation with harmful algal bloom species. Additionally, it was found that both in the coral habitat and surrounding open sea, currents, nutrients, and zooplankton may play crucial roles in determining the spatiotemporal variability in the phytoplankton community structure.

Damming exacerbates the discontinuities of phytoplankton in a subtropical river in China

Phytoplankton is sensitive to changes in river ecosystems. Increasing dams disrupt the continuity of river ecosystems. However, the spatial impacts of dams on phytoplankton have not been well documented. In this study, using multiple statistical analyses, the relationships between environmental drivers and phytoplankton community structures in natural background reaches, reservoirs, and corresponding post-dam reaches were explored in the Jiulong River with multiple cascaded dams, which encountered eutrophication and algal blooms in the past 15 years. Results illustrated that damming exacerbated longitudinal discontinuities of phytoplankton communities. The relative abundance of phytoplankton varied in three types of river sections. The average phytoplankton abundance in the reservoirs (1.62 × 105 cell·L−1) was higher than those in the natural background reaches (5.15 × 104 cell·L−1) and the corresponding downstream reaches (4.55 × 104 cell·L−1). The total β diversity ranged from 0.38 to 0.89 with an average of 0.64 and dominated by species replacement and least by species richness. The water environmental factors and hydraulic parameters rather than nutrients were more attributable to phytoplankton community variability in three river sections. These findings facilitate the management of rivers with multiple cascade dams by releasing environmental flows, jointly operating cascade hydropower stations, and developing nutrient reduction schemes to mitigate the negative impacts of damming in the river.

Estimation of indicators of phytoplankton development and water quality of the Peipus-Pskov Lake in modern conditions

Currently, there is an acute problem of pollution of the hydrosphere, which results in a drop in the stability of ecosystems, destruction of the signaling links of biocenoses, and food pyramid violation. This paper presents the results of our monitoring the current state of phytoplankton communities and water quality of the Peipus-Pskov Lake, a large transboundary reservoir located in the northwest of the Pskov region. During the growing season of 2022, 221 phytoplankton taxa with ranks below the genus from 8 divisions were identified. The average abundance of phytoplankton over the entire period of our study was 11.6 million cells/L, the average biomass was 1.6 g/m3. An ecological and geographical analysis was carried out, according to which widespread freshwater planktonic forms of microalgae predominated in the lake, preferring stagnant-flowing weakly alkaline waters. According to the Sjörensen–Chekanovsky index, the degree of commonality of the species composition of the planktonic algal floras in the Pskov and Peipsi Lakes was 73.2%. Saprobiological analysis showed that the waters of the study area in 2022 were slightly polluted (class II of water quality).

Planktonic algoflora of small rivers in urban conditions (on the example of the Mirozhka and Pskova rivers, Pskov, the Pskov Region)

The paper studies the planktonic algoflora of the Mirozhka and the Pskova Rivers. The research was carried out in the early autumn period of 2019. The taxonomic composition of the Mirozhka River included 107 species and intraspecific taxa of microalgae, the Pskova river 76 species taxa of algae from 7 phylums: Bacillariophyta, Cyanobacteria, Chlorophyta, Ochrophyta, Cryptophyta, Euglenozoa, Miozoa. The basis of the floral complex in both rivers were diatoms and green algae. The representatives of the Ochrophyta department also made a visible contribution to the species richness of the algoflora of the Mirozhka River. The degree of floral similarity of phytoplankton communities of the Mirozhka and Pskova rivers, calculated using the Sorensen-Chekanovsky index, was 55,7% (51 species of microalgae were common to the rivers). The average phytoplankton abundance in the Mirozhka River was 891,9 thousand cells/l, and in the Pskova river 199,6 thousand cells/l, biomass 366,9 micrograms/l and 79,6 micrograms/l, respectively. According to ecological and geographical analysis, freshwater widespread planktonic forms of microalgae predominated in both rivers, preferring slightly alkaline waters. Beta-mesosaprobionts prevailed in relation to organic matter pollution in rivers (38,5% the Mirozhka River; 41,8% the Pskova River), which indicates moderate pollution of the studied watercourses. The average saprobity index of the Mirozhka River and the Pskova River was 2,1 and 1,9, respectively, which makes it possible to attribute the waters of the studied watercourses to the 3rd class of quality moderately polluted.

Spatial Distribution of the Taxonomic Diversity of Phytoplankton and Bioindication of the Shallow Protected Lake Borovoe in the Burabay National Natural Park, Northern Kazakhstan

The Burabay National Natural Park unites six lakes located among the steppe landscape, with Lake Borovoe being the most visited among them. The phytoplankton of the protected Lake Borovoe was examined in the summer season of 2019, at eight stations, which were defined for the first time as the monitoring sites on the lake surface. Altogether, 72 algae and cyanobacteria species from seven taxonomic phyla were found in the Lake Borovoe phytoplankton during the study period. The most species-rich were three phyla: diatoms, green algae, and cyanobacteria. The average phytoplankton abundance was 3012.6 cells L−1, and biomass was 2383.41 mg L−1. The ecological status of the lake in 2019 was assessed based on the species richness, abundance, biomass, and calculated indices of organic pollution and toxic impact. The statistical mapping, calculated community similarity, correlation, and Redundancy Analysis (RDA) revealed zones affected by human impact. These were located in the lake shores and low-alkaline water with the saprobity index of 1.63–2.00. This is typical for naturally clean lakes, indicating the oligotrophic-to-mesotrophic status of the lake during the study period. The increase in cyanobacteria species in coastal communities can be associated with an increase in the biogenic load on the lake ecosystem in recent times. Therefore, our multivariate analysis allowed us to assess the ecological state of Lake Borovoe, which can be the result of the interaction of many external environmental factors, such as climatic conditions, long-term accumulation of organic substances, the intensity and duration of anthropogenic press, and internal lake processes such as the development of algae communities. The results suggest a tendency for the eutrophication of Lake Borovoe to increase because of pollution coming from the human impact zones on the lake shores.

Biological indicators as tools for monitoring water quality of a hot spot area on the Egyptian Mediterranean Coast

El-Mex Bay is a semi-sheltered coastal embayment located west of Alexandria, the Egyptian Mediterranean Sea. It is considered as a hot spot area receiving industrial, agricultural, and domestic wastes from the adjacent Lake Mariut through El-Umum Drain. To evaluate the water quality of the bay, phytoplankton and macroalgae as biological tools were investigated seasonally concerning physicochemical parameters from 2018 to 2019. The results indicated that the Bay harbored a diversified phytoplankton community (162 species), comprising 99 freshwater forms, 38 marine, 22 euryhaline, and only 3 brackish forms. The total average phytoplankton abundance was 419,414 unit/L. Few species were responsible for the main bulk of phytoplankton namely Merismopedia tenuissima, Cylindrotheca closterium, Cyclotella sp., Skeletonema costatum, Scenedesmus quadricauda, Scenedesmus bijugus, and Tetradesmus dimorphus. During the study period, El-Mex Bay was affected by the presence of 13 harmful and /or toxic algal species, among which the mediophyte species Skeletonema costatum was responsible for the peak occurring during autumn (2018). The results of the recorded nutrients indicated that the Bay is highly loaded, where NH4, NO2, NO3, PO4, and SiO4 attained 141.68 µM, 25.61 µM, 151.16 µM, 10.73 µM, and 232.86 µM, respectively. The macroalgal flora was represented only by the two opportunistic species (Ulva fasciata and Ulva intestinalis). Both species could survive in freshwater conditions exhibiting very broad salinity tolerance (6.51–38.41‰) and a high level of nitrogenous compounds. Those results revealed that El-Mex Bay suffers from pollution and deterioration of water quality.

Phytoplankton Community Structure in Carocok Tarusan Beach Pesisir Selatan Regency West Sumatra Province

The existence of phytoplankton in the aquatic environment greatly affects aquatic life itself. Through photosynthesis, phytoplankton is responsible for producing oxygen and nutrients, especially for other marine organisms. Furthermore, phytoplankton can be indicators of fertility and the quality of an aquatic ecosystem. The waters of Carocok Tarusan beach have congested anthropogenic activities, like shipyard and shipping, tourism, and domestic activities. This of course greatly affects the existence of phytoplankton which is very dependent on environmental conditions. This study aims to determine the structure of the phytoplankton community and its relation to the characteristics along with the quality of the waters in Carocok Tarusan beach. Phytoplankton samples were collected by using plankton net number 25 at three stations that have been determined by the purposive sampling method. The results showed that the temperature values ranged from 29.3-29.7ºC, salinity 27.7-31.3‰, brightness 1.8-3 m, pH 7, 0.3-0.6 m/s. There are 12 species from 3 classes found. The most common species found were Navicula sp, Synedra ulna sp., and Isthmia sp. The average abundance of phytoplankton at each station is 57.86-92.58 Ind/L. The results of the ANOVA test on the abundance of phytoplankton showed a significant value of 0.108, which means the P value> 0.05, this indicates that there is no significant difference in the abundance of phytoplankton between stations. The value of the species diversity index (H') of phytoplankton has an average value of 1.7436 - 2.0028. The Uniformity Index (E) has an average value ranging from 0.1393 to 0.1464. Meanwhile, the phytoplankton dominance index shows an average value of 0.2661 – 0.3191

Relationship of Nitrate and Phosphate Content with Phytoplankton Abundance at the West Kambang River Estuary, Lengayang District, Pesisir Selatan, West Sumatra

This research was conducted in February 2021 in the Estuary of the West Kambang River, Lengayang District, Pesisir Selatan, West Sumatra. This study aims to analyze the relationship between nitrate and phosphate concentrations with the abundance of phytoplankton in the West Kambang River Estuary. The method used in this study is a survey method. Determination of sampling stations was carried out by purposive sampling based on anthropogenic activities around the Estuary of the West Kambang River. Based on the results of the study, nitrate concentrations ranged from 0,76 ? 0,86 mg/l, phosphate concentrations ranged from 0,85 ? 0,94 mg/l, the average abundance of phytoplankton ranged from 201,50 ? 284,27 ind/l. Based on the one way Anova test, the concentration of nitrate, phosphate and abundance of phytoplankton did not differ significantly between stations. The results of simple linear regression test showed that the concentration of nitrate had a weak relationship with the abundance of phytoplankton and phosphate had a moderate relationship with the abundance of phytoplankton.

Abundance of Plankton in the Waters of Geger Beach, Badung Regency, Bali

Geger Beach is located in Peminge traditional village area, Sawangan, Nusa Dua, Bali which is a tourism area and there is seaweed cultivation managed by local people. Such human activity will affect the quality of the waters which will result in an increase in nutrients and organic matter which can further lead to changes in the structure of plankton. The purpose of this study is to find out the types of plankton and the abundance of plankton found in the waters of Geger Beach using the pour method. This research was conducted in March 2021. Sampling is conducted once a week at three observation points. The total phytoplankton species obtained as many as 32 species consisting of 6 classes, namely Bacillariophyceae (23 genera), Xanthophyceae (1 genus), Cyanophyceae (3 genera), Ulvophyceae (1 genus), Conjugatophyceae or Zygnematophyceae (2 genera), Coscinodiscophyceae (2 genera). The dominant type of phytoplankton found during the study was the Gyrosigma fasciola species in the Bacillariophyceae class. Meanwhile, the total zooplankton obtained by 11 species consisting of 5 classes, namely Maxillopoda (3 genera), Hexanauplia (3 genera), Magnoliopsida, Branchiopoda, and Copepoda (1 genus). The dominant type of zooplankton found during the study was the Cyclops sp. species in the Maxillopoda class. The average abundance of phytoplankton is 120 cells/l, while the average abundance of zooplankton is 20 cells/l. The average diversity value of phytoplankton is 2,7, while the diversity of zooplankton is 1,4. The average dominance index value of phytoplankton is 0,06, while the average zooplankton dominance index is 0,25.

Struktur Komunitas Fitoplankton di Kolam Bekas Pertambangan Batubara Desa Kampung Baru Kecamatan Cempaka

This study aims to determine the structure of phytoplankton communities in the pool are former coal mining Desa Kampung Baru Kecamatan Cempaka which include abundance, diversity, uniformity and dominance. Phytoplankton samples taken in two pools with a purposive sampling method with a three-point shooting at each pond. Sampling was performed three times. Phylum of phytoplankton were identified in both pools as much as 2 phylum (Chloropyta and Chrysopita) with 17 genera. Average abundance of phytoplankton in the first pool of 7174 ind / liter and 6873 ind / liter in the second pool. The average diversity index of phytoplankton in the first pool of 1.540 and 1.621 in the second pool. Average uniformity index of phytoplankton in the first pool of 0622 and 0.623 in the second pool. The average index of phytoplankton dominance in the first pool of 0271 and 0250 in the second pool. Analysis of community structure (abundance, diversity, uniformity and dominance) shows the condition of the two ponds in the state is quite stable and capable of supporting life inside the phytoplankton. Where the pool in the fertility rate is the level of contamination is, the conditions included in the category of individuals spread more evenly and there are no species that dominate other species in the extreme.

PLANKTON ANALYSIS IN THE PONDS OF CATFISH (Clarias sp) AND NILE TILAPIA (Oreochromis niloticus)

Clarias and Nile tilapia ponds contain high organic matter levels which will be decomposed by bacteria. It also produces carbon dioxide, which can be utilized by phytoplankton for photosynthesis process. This research aimed to compare the types of phytoplankton and zooplankton in Clarias and Nila tilapia ponds for eutrophication and water quality control. The research was conducted in August-September 2020. The water samples were taken using plankton net to become 35 ml from Clarias and Nile tilapia ponds. Analysis of plankton abudance, diversity, Evenness and Dominance Index was carried out in the Laboratorium Hidrobiologi. The analysis result of the average abundance of phytoplankton in the Clarias ponds was 71.026 cell/mL (11 genera), and zooplankton was 93 ind/mL (4 genera). Meanwhile in Nile tilapia ponds was 1.503 cell/mL (9 genera), and zooplankton was 91 ind/mL (1 genus). The average of zooplankton in Nile tilapia pond was higher than in catfish ponds; since Clarias are carnivores while Tilapia are omnivores. The plankton diversity index of catfish pond was average 0.817, while in Nile Tilapia was average 0.553. The evenness ndex of catfish pond was average 0.5, while in Nile Tilapia was average 0,4. The dominance index of catfish pond was average 0.59, while in Nile Tilapia was average 0.77. The conclusion obtained is the type of phytoplankton in Catfish pond consisted of 11 genera (99.62%) and zooplankton of 4 genera (0.38%), while in Nile Tilapia pond the type of phytoplankton consisted of 9 genera (97.85%) and zooplankton of 1 genera (2.15%).

Assessment of Seasonal Waters Quality Based on Abundance, Diversity, and Domination of Phytoplankton in Bajulmati Reservoir

Water quality assessment can be carried out through physical, chemical, and biological analyses. Phytoplankton is a biological microorganism that is usually used as indicators to assess surface water quality, specifically primary productivity. Bajulmati Reservoir is located in Banyuwangi, East Java, which functions as irrigation for agricultural and fisheries land. The purpose of this study was to analyze the productivity of reservoir waters based on phytoplankton abundance. The method used is purposive sampling with four sampling point stations from the entire reservoir area. The phytoplankton found were nine genera, consisting of 5 genera from the Cyanophyceae class, and one genus from each class, namely the Chlorophyceae, Bacillariophyceae, Euglenophyceae, and Dinophyceae classes. The productivity of the Bajulmati reservoir is included in the eutrophic category, with an average abundance of phytoplankton of 15.215 ind.L−1. Meanwhile, the diversity index shows that the distribution of stable individuals and communities is low, namely 0.87. Despite this, the Cyanophyceae class is dominating with the dominance index was 0.52.

基于功能类群分析呼兰河口湿地浮游植物群落结构特征

PDF HTML阅读 XML下载 导出引用 引用提醒 基于功能类群分析呼兰河口湿地浮游植物群落结构特征 DOI: 10.5846/stxb201911152444 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目（31870187）；哈尔滨师范大学科研启动金项目（XKB201912）；哈尔滨师范大学高等教育教学改革研究项目，哈尔滨师范大学研究生教育教学改革项目 Analysis of phytoplankton structure based on different functional groups in Hulanhe Wetland Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:浮游植物对水环境条件变化敏感，其群落演替特征被广泛应用于指示水环境变化。基于3种浮游植物功能类群方法，对呼兰河口湿地浮游植物群落结构进行研究。于2018年春季（4、5月）、夏季（6、7、8月）和秋季（9、10月）三季，在呼兰河口湿地共设置11个采样点，通过ASNOSIM和SIMPER分析探索FG、MFG和MBFG功能类群的演替特征，基于RDA分析阐述功能类群对环境因子的响应模式。研究期间共鉴定浮游植物243个分类单位，隶属于7门9纲18目32科75属；其种类组成主要以绿藻门（46.09%）、裸藻门（19.34%）和硅藻门（18.52%）为主。共划分FG功能类群25个，MFG功能类群20个，MBFG功能类群6个；ANOSIM分析表明不同季节之间FG和MFG功能类群结构差异显著；SIMPER分析表明S1/Lo/W1/P/J/Y、9b/5a/11b/6a/2c/2d/1c和Ⅲ/Ⅰ类群是影响不同季节之间功能类群变化的主要类群；RDA分析表明，FG、MFG和MBFG功能类群的演替受多种环境因素共同影响，其中pH、BOD5、Tur.和CODMn与功能类群演替关系密切。相较于MBFG功能类群，FG和MFG功能类群能更好的响应呼兰河口湿地水环境的空间异质性。 Abstract:The Hulanhe Wetland is located in northeastern of China, and plays an important role in maintaining the biodiversity and regulating the microclimate in Harbin city. Although phytoplankton functional group studies on wetlands in northern China have increased recently, studies of the phytoplankton functional group in the Hulanhe Wetland are limited. To better understand processes of phytoplankton community succession in relation to environmental parameters, the functional mechanisms of biological communities may be better understood if species are pooled into groups with similar characteristics. Therefore, a detailed survey of three phytoplankton functional groups in spring, summer, and autumn are necessary. In this study, three different phytoplankton functional group methods were used to study phytoplankton community structure. Phytoplankton was qualitatively and quantitatively collected from 11 sampling sites in four typical habitats. The samples were collected in spring (April, May), summer (June, July, August), and autumn (September, October). A total of eleven sample sites were selected. We explored the succession characteristics of FG (Functional Group), MFG (Morpho-Functional Group) and MBFG (Morphology-Based Functional Group) functional groups by applying ASNOSIM and SIMPER analysis. A total of 243 phytoplankton species were identified, belonging to 7 phyla, 9 classes, 18 orders, 32 families and 75 genera. The phytoplankton species composition was dominated by and Chlorophyta (46.09%), followed by Euglenophyta (19.34%), Bacillariophyta (18.52%) and Cyanophyta (11.11%). During the study, the results showed that the average abundance of phytoplankton in the Hulanhe Wetland was significantly different (P<0.05). According to the abundance of phytoplankton, B (Cyclotella Kützing), J (Scenedesmus Meyen, Tetrastrum Chodat), D (Nitzschia Hassall), S1 (Pseudanabaena limnetica (Lemmermann) Komárek), Y (Cryptomonas erosa Hering, Cryptomonas ovata Hering) and W1 (Euglena Ehrenberg, Phacus Dujardin) were dominant in the functional groups. 25 functional groups, 20 Morpho-Functional Groups and 6 Morphology-based Functional Groups were identified during the study. The ANOSIM analysis showed significant differences in FG and MFG functional group structures between seasons. The SIMPER analysis indicated that the primary contributing phytoplankton functional groups were S1/Lo (Merismopedia Meyen)/W1/P (Melosira granulata (Ehrenberg) Ralfs)/J/Y, 9b (small unicells-Chlorococcales)/5a (thin fifilaments Oscillatoriales)/11b (Chlorococcales-Gelatinous colonies)/6a (large Centrics)/2c (small Euglenophytes)/2d (Cryptophytes)/1c (large Euglenophytes) and Ⅲ (large fifilaments)/Ⅰ (small organisms with high S/V). Redundancy Analysis (RDA) based on FG, MFG and MBFG and eleven environmental variables revealed that CODMn was the key factor driving the phytoplankton functional group succession, and Turbidity (Tur.), BOD5 and pH were closely related to phytoplankton functional group patterns. We found that MBFG approach was not as sensitive as FG and MFG approach in describing the variability of phytoplankton groups in the environment. We suggested that MBFG approach was not suitable for indicating the temperate wetland water environment condition. 参考文献 相似文献 引证文献

Spatial and temporal distribution of phytoplankton with emphasis on the harmful and toxic algae in the Limboto Lake

This study aims to describe Limboto Lake's condition based on the spatial-temporal abundance of phytoplankton and the presence of harmful algae species. Sampling was conducted in February, March, and April 2018 at six stations. The phytoplankton found in Limboto Lake consisted of 7 divisions from 80 species, namely Chlorophyta (35 species), Euglenophyta (17 species), Bacillarophyta (13 species), Cyanophyta (7 species), Cryptophyta (4 species), Dinophyta (3 species) and Chyrosphyta (1 species). The results of the phytoplankton distribution analysis in Limboto Lake varied on average among stations as well as observation times. The results show that the average of phytoplankton abundance at stations 1, stations 2, stations 3, and stations 4 categorized as medium polluted waters with 4,903 ind/L, 5,000 ind/ L, 9,418 ind/L, and 10,049 ind/L, respectively. The abundance at station five is included in the lightly polluted category with an average phytoplankton abundance of 1,541 ind/L, while station 6 is in the heavily polluted category with the average value of 20,894 ind/L. Species that can be used as indicator species for pollution are those with the highest abundance value, namely Microcystis sp., which indicates that Limboto Lake contains high nitrate and phosphate.

Spatial Distribution of Plankton in Citanduy River, Cisayong Region, Tasikmalaya, West Java

The Cisayong area of ​​Tasikmalaya Regency is an area that is passed by the Citanduy River. The condition of the waters in the Citanduy River in Cisayong area, has received various waste inputs which will affect the quality of the river waters and cause a decrease in water fertility. Plankton can be used as an indicator of water fertility. This study aims to determine the spatial distribution of plankton in the Citanduy River, Cisayong Tasikmalaya Region, West Java. This research was conducted from January 2020 to February 2020. The research stations are located in four locations which are determined based on environmental and land use factors with a sampling period span of once every seven days. This research was conducted using a survey method and the data were analyzed descriptively and comparatively. The results showed that there were 67 genera of plankton from 5 phytoplankton phyla and 4 zooplankton phyla with most of the phytoplankton groups found from the Bacillariophyceae class and the zooplankton group from the Tubulinea class. The total average abundance of phytoplankton was 11,534 ind / L and the total average abundance of zooplankton was 295 ind / L. The biological index values ​​of the average diversity and dominance of phytoplankton were 2.72 and 0.11, while the average values ​​of diversity and dominance of zooplankton were 0.92 and 0.47. The results of the plankton spatial distribution show that the fertility of the waters in Citanduy River is classified as oligotrophic for station 1 and mesotrophic waters for stations 2,3, and 4.

The profound influence of Kuroshio intrusion on microphytoplankton community in the northeastern South China Sea

To further understand the effect of Kuroshio intrusion on phytoplankton community structure in the northeastern South China Sea (NSCS, 14°-23°N, 114°-124°E), one targeted cruise was carried out from July to August, 2017. A total of 79 genera and 287 species were identified, mainly including Bacillariophyta (129 species), Pyrrophyta (150 species), Cyanophyta (4 species), Chrysophyta (3 species) and Haptophyta (1 species). The average abundance of phytoplankton was 2.14×103 cells/L, and Cyanobacterium was dominant species accounting for 86.84% of total phytoplankton abundance. The abundance and distribution of dominant Cyanobacterium were obviously various along the flow of the Kuroshio, indicating the Cyanobacterium was profoundly influenced by the physical process of the Kuroshio. Therefore, Cyanobacterium could be used to indicate the influence of Kuroshio intrusion. In addition, the key controlling factors of the phytoplankton community were nitrogen, silicate, phosphate and temperature, according to Canonical Correspondence Analysis. However, the variability of these chemical parameters in the study water was similarly induced by the physical process of circulations. Based on the cluster analysis, the similarity of phytoplankton community is surprisingly divided by the regional influence of the Kuroshio intrusion, which indicated Kuroshio intrusion regulates phytoplankton community in the NSCS.

Phytoplankton community structure and ecological evaluation in summer, Lake Changhai of Jiuzhaigou National Nature Reserve

高山湖泊对于全球气候变化及人类影响是一个极为敏感的参照系统.九寨沟国家级自然保护区长海作为一个独特的高山湖泊，研究其浮游植物群落结构及其与环境的关系，评估其水质现状及影响因素，有着重要的意义.本文于2014年7月对长海浮游植物群落结构进行了研究.全湖共布设12个采样点，并在中心采样点进行了垂直分层采样.本次调查共发现浮游植物6门38属63种，平均丰度为6.98×10⁵ cells/L，平均生物量为0.31 mg/L.浮游植物的水平分布差异不大；在垂直分布上，浮游植物的丰度从表层0.5 m至水下50 m呈现先增加后减少的趋势，在20 m水深处达到最大.长海浮游植物的优势种是长海小环藻（Cyclotella changhai）和飞燕角甲藻（Ceratium hirundinella），长海小环藻数量较多，飞燕角甲藻生物量较大.长海浮游植物多样性指数较低，综合各类水质评价方法，可以得出九寨沟长海处于贫-中营养状态.;Alpine lakes are sensitive reference systems of global climatic change and other human impacts. As a unique alpine lake, Lake Changhai of Jiuzhaigou National Nature Reserve has important significance in studying its phytoplankton community structure and it's relationship with the environment. It is also important to assess the status of water quality and its influencing factors. In order to understand the phytoplankton community structure, 12 sites were selected to collect phytoplankton samples in July 2014. Vertical stratified sampling was performed at the central sampling point. The 63 taxa of phytoplankton belonging to 38 genera in 6 phyla were identified, the average phytoplankton abundance was 6.98×10⁵ cells/L, the average phytoplankton biomass was 0.31 mg/L. There is no significant difference in the horizontal distribution of the phytoplankton. In the vertical distribution, the abundance of phytoplankton increased first and then decreased from 0.5 m to 50 m, and reached the maximum at the depth of 20 m. Cyclotella changhai and Ceratium hirundinella were the dominant species. Cyclotella changhai were higher amounts, Ceratium hirundinella were higher biomass. The phytoplankton diversity index was low. Synthesizing all kinds of methods to evaluate water quality, Lake Changhai was in a poor-medium pollution state.

Spatiotemporal Changes in the Phytoplankton in Lake Baikal during Late Summer: I. Water Temperature and Phytoplankton Abundance

Results of a study of the water temperature and phytoplankton abundance in different regions of Lake Baikal according to 15 expeditions from 1994 to 2013 during late summer are present. The spatial distribution and interannual dynamics of phytoplankton are analyzed. The total abundance of phytoplankton in late summer is shown to be high. Its average long-term value for all of the open area of Lake Baikal is 532 ± 17 thousand cells/L. In Southern Baikal, the west coast is characterized by higher average phytoplankton abundance; in Middle and Northern Baikal, the east coast is rich. No significant differences were found between the hollows of the lake in terms of the development of late summer phytoplankton. The long-term average abundance of phytoplankton in the southern, middle, and northern hollows differs only by ≤1.2 times, but in the middle hollow it is significantly higher than in the northern. In the long-term dynamics, no significant increase in the abundance of late summer phytoplankton was recorded in any of the regions of the lake. The dependence of the total phytoplankton abundance on water temperature is weak; the correlation coefficients between the average annual values ​​of these indicators are ≤0.50.

INDEKS KEANEKARAGAMAN KOMUNITAS FITOPLANKTON SEBAGAI BIOINDIKATOR SAPROBITAS PERAIRAN DI SEKITAR PEMBANGKIT LISTRIK TENAGA UAP (PLTU) KABUPATEN NAGAN RAYA

This research aims to know the structure of the phytoplankton community in waters of PLTU Nagan Raya and to know the index of saprobitas based on the quality of waters in physics and chemistry of water. Research methods are laboratories where data research results obtained from the measurement results directly (in situ). The analysis conducted in the laboratory include identification and measurement of physical and chemical parameters of the water. The parameters in the observed in this research is phytoplankton abundance, diversity index, uniformity coefficient, saprobik, domination, phytoplankton, and water quality index. The results of the research there were 21 types of Phytoplankton Composition, from the 5th Division Cyanophyta, Euglenophyta, namely Chryshophyta, Bacillariophyta and Chlorophyta. The average phytoplankton abundance ranged from 20-72 cells/l, with an abundance of phytoplankton dominated Chryshophyta i.e. 42,66-2,66%. Judging from the average index of diversity IE 0-2.23; the uniformity that is 0-0.73; the dominance of 0 – 0.72; with saprobitas coefficients of phytoplankton ranges from 0.25 – 1.18 and average water quality index range 6.2466 – 63.6272; The result indicates the quality of the waters to provide moderate to very bad.