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1

Identification of Environmental Factors Determining the Diversity and Abundance of Phytoplankton in Menjer Lake, Wonosobo, Indonesia

Piranti Agatha Sih, Widyartini Dwi Sunu, Retna USR Diana, Noviana Fariza

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 2

272--280

EN

Phytoplankton are primary producers in aquatic ecosystems, their abundance is determined by environmental changes, so phytoplankton are often used as bioindicators of waters. The aim of this research was to determine the diversity and abundance of phytoplankton in Menjer Lake, to measure the environmental factors that determine the diversity and abundance of phytoplankton, and to determine the environmental factors that most influence the diversity and abundance of phytoplankton in Menjer Lake. This research uses a survey method in 5 areas (inlet, middle of the lake, aquaculture using floating net cage, tourism, and outlet). The parameters observed were the diversity and abundance of phytoplankton as well as the concentration of water quality parameters that determine the presence of phytoplankton (temperature, light penetration, pH, DO, TSS, TDS, PO4 and NO3). To determine the environmental factors that most influence the diversity and abundance of phytoplankton were analyzed using the principal component analyses method with Past 4.10 software. The community structure of phytoplankton in Menjer Lake was dominated by Bacillariophyta (83%). The factors determining the development of phytoplankton in Menjer Lake are influenced most by light penetration and PO4 concentration. The input of PO4 concentration from the water catchment area must be controlled to prevent phytoplankton blooming in Menjer Lake.

2

Effects of the tide on the temporal and spatial physicochemical structure of the Kienké river estuary (South Atlantic Coast of Cameroon, Kribi) and its phytoplankton

Mama Anselme Crépin, Ghepdeu Gisele Flodore Youbouni, Fossi Tankoua Olivia, Bonga Manfred Desire, Abouga-Bodo Willy Karol, Mandeng Thérésa Irma, Owona-Edoa François Désiré, Tangko Noel Chuye, Ngoupayou-Ndam Jules Rémi

Oceanological and Hydrobiological Studies

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2023

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Vol. 52, No. 1

20--40

EN

The present work aimed to understand the physicochemical and phytoplanktonic structure of the Kienke estuary water in the urban area of Kribi town in relation to human activities and fluvial or oceanic influences. Field investigations and laboratory work were devoted to the sampling and measurement of some physicochemical and biological parameters, specific treatments and classical statistics (descriptive, multidimensional) of variables. Estuary water is characterised by an instability and spatio-temporal variations in its physicochemical parameters. The most sensitive parameters are as follows: a temperature ranging between 22.6°C and 31°C under the influence of atmospheric variations, electrical conductivity and salinity that are relatively high (0.22 < C. E < 49.70 mS cm-1; avg =16.56 mS cm-1; 0 < Sal < 29.32 PSU; avg = 11.51 PSU), and a pH that is overall acidic to basic (6 < pH < 8.86; avg = 7.75 ± 0.82). The nutrients variation (ammonium, nitrite, nitrate and orthophosphate) is very low in space and time, with a longitudinal distribution controlled by tidal flows, river flows and the biological pump. For the 64 samples collected, 167 phytoplankton taxa were identified. The most abundant (36.36%) were Chrysophyta Division, followed by Chlorophyta. Species richness is marked by brackish water taxa. According to this structure and the combination of both gradients, mineratilisation and organic matter enrichment is of a physicochemical typology, and the biotypology is hydrotypologically dependent.

3

The influence of biochemical parameters on primary production in the Gulf of Gdańsk region : A model study

Janecki Maciej, Dybowski Dawid, Dzierzbicka-Głowacka Lidia

Oceanologia

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2023

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Vol. 65 (4)

517--533

EN

Understanding the changing levels of biochemical parameters and the factors that influence them throughout the seasons is crucial for comprehending the dynamics of marine ecosystems. It also helps us identify potential threats that could harm their condition, aiding decision-making processes related to their protection. This study focuses on examining the variations in nutrients (such as nitrates, phosphates, and silicates), dissolved oxygen, and phytoplankton within the Gulf of Gdańsk. Additionally, we analyze the primary production process at three representative locations. To achieve this, we used data from the EcoFish biochemical numerical model. To ensure the model's accuracy, we compared its results with in situ data from the ICES database. The comparison revealed high correlations and minimal errors. Furthermore, we investigated how limiting factors impact primary phytoplankton production and demonstrated how the intensity of spring diatom blooms influences the nature of cyanobacterial blooms in the summer.

4

Phytoplankton Dynamics and Its Relation to Physicochemical Parameters in the Dry Season of Maninjau Lake, West Sumatra, Indonesia

Komala Puti Sri, Silvia Shinta, Windi Sherina

Journal of Ecological Engineering

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2023

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Vol. 24, nr 9

218--231

EN

Physicochemical parameters play a significant role in determining phytoplankton structure and dynamics in the lake. The present study investigated the phytoplankton dynamics and their correlation with physicochemical parameters in the dry season of Maninjau Lake. The parameters measured, including temperature, transparency, pH, DO, TN, and TP concentrations, were collected from seven lake locations, i.e., in the middle of the lake, near domestic, hydropower, endemic fisheries, and aquaculture cage areas, and inlet-outlet rivers. Phytoplankton samples were collected from the middle of the lake, near domestic and aquaculture cage areas. TSI analysis shows that Maninjau Lake was hypereutrophic, with an average TSI of 101.15. The phytoplankton community comprises six classes and 22 species dominated by Microcystis aeroginosa and Synedra acus. Bacillariophyceae had the highest phytoplankton concentration, while Cyanophyceae had the highest density. The diversity and equity index of the phytoplankton community structure were low and less evenly distributed, confirming that the lake was hypereutrophic. The highest diversity index was found in the middle of the lake or the most profound part, while the lowest was near the domestic area. Among the physicochemical parameters, transparency has a strong correlation with dominant phytoplankton.

5

Impact of Water Stress on the Planktonic Biodiversity of the Youssef Ben Tachafine Dam (Souss Massa, Morocco)

Boudarfa Fatima, Gallouli El Mahjoub, El Hafa Mohamed, Aamiri Ahmed, Oulad Ali Hassan

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 8

97--106

EN

Drought is a large-scale disturbance that affects freshwater ecosystems worldwide. This recurrent phenomenon in Morocco, has experienced severe episodes during the last decade and has caused water stress in several aquatic ecosystems including the Youssef Ben Tachafine dam. Indeed, the volume of this reservoir has experienced its lowest historical hydrological level (12%) during the study period. To study the effects of water stress on water quality and planktonic community structure, water samples were collected from January 2019 to December 2020 at nine depths. The physicochemical parameters of the water were measured in parallel with the qualitative and quantitative study of the phytoplankton and zooplankton communities. The results obtained show a low planktonic diversity with only 43 phytoplanktonic species and 27 zooplanktonic species. The phytoplankton showed an almost permanent predominance of Chlorophyceae (85%), dominated by Closterium pronum, followed by Diatomophyceae (9.5%), dominated by Cyclotella ocellata. Rotifers represent the most abundant zooplanktonic group during the study period with two dominant species (Keratella tecta and Polyarthra vulgaris). Statistical analysis of the data from this study, using R software, revealed a negative correlation between Cladoceran species, Copepods and the diatom Cyclotella ocellata on the one hand and the decrease in water level, temperature and enrichment of the environment in nutrients and phytoplanktonic biomass on the other. This study shows that the effect of the extreme drought, which the Youssef Ben Tachafine dam has experienced, has altered the diversity and structure of planktonic communities, which threatens the sustainability of ecological services of this ecosystem.

6

Correlation Between Surface Water Quality and Plankton Composition in Water Bodies in Hau Giang Province, Vietnam

Quang Truong Chi, Giao Nguyen Thanh

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 4

1--14

EN

The study was carried out to assess surface water quality in water bodies in Hau Giang province, Vietnam using individual surface water quality parameters and water quality index. In addition, the correlation of phytoplankton and zooplankton composition with surface water quality was also examined. The results showed that surface water quality in Hau Giang province was contaminated with organic matters, nutrients, iron and microorganisms. The water quality index (WQI= 37-84) showed that surface water ranged from moderate to good. A total of 164 species belonging to five phyla of phytoplankton were recorded with the density from 370–2260 individuals/L and 91 species belonging to five phyla of zooplankton with a density of 11,332–121,600 individuals/L. The predominance of the phytoplankton species Oscillaroria, Euglena, Phacus and the predominance of zooplankton species of the Nauplius, Rotifera and Protozoa signalize an aquatic environment rich in organic matters and nutrients. The correlation results showed that BOD, COD, NH4+-N, NO3--N and PO43--P were closely related to the density of phytoplankton while pH, DO, BOD, NH4+-N and coliform play an important role in determining the density of zooplankton species.

7

Temporal variations of phytoplankton community and their correlation with environmental factors in the coastal waters of the Çanakkale Strait in 2018

Demir Egemen ̇Inan, Turkoglu Muhammet

Oceanologia

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2022

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No. 64 (1)

176--197

EN

In order to investigate temporal variations in phytoplankton connected with hydrography, high-resolution (twice a week) samplings were carried out between January and December 2018 at a single, shallow water station in the Dardanelles. Diatoms dominated in early and mid-winter, late spring and early summer, and between August and October. Whereas dinoflagellates dominated in the period from mid-February to the end of the third week of May, mid-summer, and late autumn. Other groups were generally more abundant in the early summer and mid-autumn than any other period. Late spring and early summer, mid-autumn and middle winter were the important bloom periods. The average contribution of diatom abundance (5.00 × 105±7.80 × 105 cells L−1) to average total phytoplankton abundance (9.63 × 105±7.88 × 105 cells L−1) was above 50% (average: 51.88%) during the year except spring (34.32%). However, the average contribution of dinoflagellates (43.32±20.69%) and others (4.81±6.99%) to the total phytoplankton abundance were lower than the abundance of the diatoms (51.88±21.61%). The study revealed a decrease both in the total number of algal blooms which also included HABs and their densities in the region compared to the previous findings. These observations seem to evidence environmental status improvement of the investigated area, manifested in an average chlorophyll a concentration (0.71±0.52 µg L−1) and quantitative phytoplankton structure (103 to 105 cells L−1).

8

Size-fractionated primary production in the south-eastern Black Sea

Agirbas Ertugrul, Bakirci Mustafa

Oceanologia

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2022

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No. 64 (2)

244--266

EN

Size-fractionated primary production (PP) and chlorophyll-a (Chl-a) with phytoplankton abundance and nutrients were investigated in the south-eastern Black Sea from November 2014 to August 2015. A 14C radio-tracing technique was used to estimate phytoplankton primary production. C-14 experiments revealed that total PP ranged from 295 mgC m−2 d−1 to 5931 mgC m−2 d−1 along the study area. Size-fractionated PP varied from 84 to 1848 mgC m−2 d−1, from 96 to 3156 mgC m−2 d−1 and from 56 to 3363 mgC m−2 d−1 for pico-, nano- and microphytoplankton, respectively. Overall, winter (4163 mgC m−2 d−1) and spring (5931 mgC m−2 d−1) were the most productive seasons, which coincided with high phytoplankton abundance. Contributions of microphytoplankton and nanophytoplankton were prominent in spring with maximum PP values. Winter was the second productive season with high contributions of nano- and microphytoplankton PP. Summer and autumn were less productive seasons, which were characterised by a high contribution of pico- and nanophytoplankton PP. Dinoflagellates were represented with the highest species richness (68 species, 53.54%) and diatoms were the second group along the area. Diatoms and other phytoplankton species (mainly Emiliania huxleyi) were the most abundant groups in terms of quantitative contribution. The results show that microphytoplankton along the study area are responsible for the majority of PP. However, the measured high Chl-a against low size-fractionated PP clearly indicates that smaller groups (i.e., pico- and nanophytoplankton) were dominant during these periods. Hence, the quantification of size-fractionated PP rates together with ecological indicators will allow for a more comprehensive assessment of the Black Sea ecosystem.

9

Noctiluca blooms intensify when northwesterly winds complement northeasterlies in the northern Arabian Sea: Possible implications

Sarma Nittala Subrahmanya, Baliarsingh Sanjiba Kumar, Pandi Sudarsana Rao, Lotliker Aneesh Anandrao, Samanta Alakes

Oceanologia

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2022

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No. 64 (4)

717--734

EN

Wind systems are known as nutrient sources playing significant roles in the oceanic realm and global climate oscillations. This study explores, for the first time, the effect of winds on the winter blooms of the mixotrophic dinoflagellate, the green variant of Noctiluca scintillans (NSG) in the northern Arabian Sea. When the NSG abundance was lower (i.e., <∼10000 cells l−1), it was coupled to silicic acid (H4SiO4), on which diatoms (phytoplankton) in turn depended. At higher abundance (i.e., NSG>∼10000 cells l−1), H4SiO4 and H4SiO4:DIN (dissolved inorganic nitrogen) ratio fell. The NSG was then intensely green and chlorophyll-a richer, attributed to a change in the mode of NSG's nutrition from heterotrophy to autotrophy-dominance. The back-trajectory model revealed that the winds were mostly northeasterly (NE) initially (during February) and were north-westerly (NW) towards the end of winter (March). Separately for the NE and NW winds, the NSG abundance was 10655±18628 and 28896±46225 cells l−1, respectively. The H4SiO4:DIN ratio correspondingly reached <0.2 and ≥0.4. The NSG was modelled with high significance (p<0.001, N=33) versus the NE and NW wind speeds. Thus, while the NE winds deepened the mixed layer and caused nutrient enrichment and phytoplankton production, the NW winds facilitated the recovery of the H4SiO4:DIN ratio and economical use of H4SiO4 for phytoplankton production. It is hypothesized that this process is helped by iron input from NW desert winds during the latter part of winter when the NSG blooms intensify.

10

Multivariate approach to evaluate the factors controlling the phytoplankton abundance and diversity along the coastal waters of Diu, northeastern Arabian Sea

Kumar Ponnusamy Sathish, Venkatnarayanan Srinivas, Pandey Vikas, Ratnam Krupa, Jha Dilip Kumar, Rajaguru S., Dharani Gopal, James Rathinam Arthur, Atmanand Malayath Aravindakshan

Oceanologia

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2022

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No. 64 (2)

267--275

EN

The present study investigated the phytoplankton assemblage and diversity with physicochemical parameters of Diu coastal waters in different seasons during 2018–19. During the study period, 61 phytoplankton species comprising diatoms (50 sp.), dinoflagellates (8 sp.), and cyanophyceae (3 sp.) were recorded. Diatom was found to be a major community and contributed 79 to 99% of total phytoplankton abundance. Reduction in dinoflagellate and dominance of pennate-diatoms were observed during the monsoon. Chlorophyll-a concentration also showed a similar trend and decreased during the monsoon. However, the phytoplankton abundance was low particularly during the monsoon which might be due to the elevated total suspended solids (TSS) load. Canonical correspondence analysis revealed that diatoms were able to survive in high TSS with the support of high nutrients; while dinoflagellates were limited due to those conditions. Overall, the reduction in phytoplankton abundance, diversity, and biomass was recorded due to the elevated TSS input along the coastal waters of Diu.

11

Asterionellopsis glacialis (Family: Fragilariaceae, Class: Bacillariophyceae, Phylum: Ochrophyta) bloom and its impact on plankton dynamics at Kalpakkam (Bay of Bengal, Southeast coast of India)

Sahu Gouri, Mohanty Ajit Kumar, Sarangi Ranjit Kumar, Satpathy Kamala Kanta

Oceanologia

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2022

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No. 64 (1)

145--149

EN

An intense bloom of Asterionellopsis glacialis (Family: Flagilariaceae; Class: Bacillariophyceae; Phylum: Ochrophyta) was observed in the near-shore waters at Kalpakkam, Tamil Nadu. Proliferation was supported by the favorable temperature, salinity, and nutrient levels in the coastal waters prevailing in the post-northeast monsoon period. BIOENV analysis and PCA confirmed salinity and nitrate as the key environmental factors responsible for the A. glacialis abundance. Cluster analysis further supported the distinct state of coastal water during the bloom with respect to physicochemical properties. The bloom period was floristically and faunistically richer than the pre- and post-bloom periods. The cluster and nMDS analysis confirmed the effects of bloom on plankton dynamics in the near-shore waters at Kalpakkam. The dominance of meroplankters especially, Cirripedia nauplii and Bivalvia larvae over Copepoda during the peak bloom period, was a significant result of the study. PCA ordination plot for the quantitative aspects of phytoplankton and zooplankton groups further supported the above observation. Among Copepoda, Cyclopoida and Poecilostomatoida (mostly carnivorous) exceeded the Calanoida (mostly herbivorous) during the peak bloom period unlike the reverse trend observed during other periods. Fish eggs and larvae were available in substantial numbers during the bloom which indicated their proliferation in the presence of the blooming diatom standing stock as the food material.

12

Use of Harmful Algae Presence to Assess Water Quality in Lake Ranu Grati, Indonesia

Sunadji, Mahmudi Mohammad, Lusiana Evellin Dewi, Tobuku Ridwan

Ecological Engineering & Environmental Technology

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2022

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Vol. 23, iss. 6

118--127

EN

The evaluation of water quality is commonly conducted by measuring physicochemical parameters. However, to enable identification of water quality changes of aquatic ecosystems, such as lakes, requires long time series data sampling. In this study, we performed water quality assessments by utilising the presence of potential harmful algae presence in Lake Ranu Grati, Indonesia. We conducted water sampling to evaluate 13 water quality parameters (in-situ and ex-situ) and identified the phytoplankton community structure of the lake at seven sampling sites from December 2018 to February 2019. To assess the water quality of the lake, we used two approaches. First, calculated the classical water quality index using the STORET method. Second, identified the potential harmful algae from the phytoplankton community structure of Lake Ranu Grati, and then determined the water quality factors related to its occurrence using canonical correspondence analysis. The results showed that water quality conditio of Lake Ranu Grati was optimum except for COD, BOD and ammonia. The STORET index also classified the seven sites in Lake Ranu Grati as lightly polluted and moderately polluted. Considering the presence of potentially harmful algae from the Cyanophyta and Euglenophyta divisions, it was suggested that Sites 6 and 7 were the most polluted areas of Lake Ranu Grati, which corresponded to the high concentration of COD and BOD. This finding indicates that agricultural and aquaculture activities around the lake need to be controlled to maintain the sustainability of the water quality condition of Lake Ranu Grati.

13

The Features of Eutrophication Processes in the Water of the Uzh River

Kotsiuba Iryna, Lukianova Vitalina, Anpilova Yevheniia, Yelnikova Tetiana, Herasymchuk Olena, Spasichenko Oksana

Ecological Engineering & Environmental Technology

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2022

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Vol. 23, iss. 2

9--15

EN

The chemical and hydrobiological analyses of water quality of the Uzh river of Korosten district and the city of Korosten of the Zhytomyr region were conducted. The influence of anthropogenic loads on the river eutrophication processes was estimated. The peculiarities of the course of eutrophic processes in the reservoirs of the Uzh river basin within the Korosten district and the city of Korosten were established. As a result of research, it was found that the phytoplankton in the surface waters of the Uzh river of Korosten district was represented by diatoms, as well as green, blue-green, euglenophytic, golden and dinophytic algae. Periods of their intensive reproduction were revealed for all departments of algae. Seasonal fluctuations in the content of biogenic elements of phosphorus and nitrogen dissolved in oxygen water, as well as their influence on the development of certain departments of algae were revealed. Statistical modelling of the processes of development of blue-green, and green algae as well as diatoms in the river Uzh of Korosten district on the average values of their content for less than three years was conducted. Changes in the qualitative and quantitative composition of algae during the year were used to build the models. The obtained experimental data and their revealed features were generalized in the form of linear and nonlinear statistical mathematical models of eutrophication processes. The general appearances of the functions that describe these processes; numerical values of the coefficients of the function and graphs were constructed as well as modeling errors were defined.

14

Spatio-temporal variation of microphytoplankton communities in Obhur Creek, the central Red Sea

El-Sherbiny Mohsen M., Al-Harbi Mamdouh A., Kumar Anand J.

Oceanological and Hydrobiological Studies

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2021

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Vol. 50, No. 1

98--114

EN

The abundance and distribution of microphyto-plankton and related physicochemical factors were assessed monthly in Obhur Creek, the central Red Sea. Sampling was carried out near the entrance, the middle and end parts of the creek. During the course of the present study, the Red Sea was characterized by predominantly oligotrophic conditions. Nutrient concentrations were relatively higher in the end part of the creek compared to the two other study sites. Chlorophyll a was also low throughout the year (average: 0.35 ± 0.32 mg m−3), except in May when it showed clear peaks at open-water and middle sites of the creek (1.85 and 1.04 mg m−3, respectively). Phytoplankton abundance followed a similar pattern to that of chlorophyll a with considerably higher abundance at these sites in May (3063.27 × 103 and 1082.34 × 103 individuals m−3, respectively). This unusually higher abundance was mostly due to the proliferation of the diatom Pseudo-nitzschia cf. delicatissima (Cleve) Heiden. Silicate concentrations were statistically significantly correlated with total phytoplankton. A total of 220 phytoplankton species were recorded during the study period (117 diatoms, 99 dinoflagellates and four cyanophytes). Diatoms dominated in the phytoplankton abundance (75%) and were followed by dinoflagellates (20%), while cyanophytes accounted for a minimal proportion. Of all phytoplankton species observed during the study, 21 diatom and four dinoflagellate species were considered as new records for the Red Sea, and two diatom and 14 dinoflagellate species were listed as harmful algal species worldwide.

15

Response of coastal phytoplankton to upwelling induced hydrological changes in the Alappuzha mud bank region, southwest coast of India

Madhu Nikathithara Velappan, Anil Peariya, Meenu Paul, Gireeshkumar Thundiyil Raju, Muraleedharan Kallungal Ravunnikutty, Rehitha Thekkendavida Velloth, Dayana Mathew, Vishal Chazhikulam Rajan

Oceanologia

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2021

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No. 63 (2)

261--275

EN

The response of phytoplankton community to the co-existing events of coastal upwelling and mud banks in the nearshore waters of Alappuzha (15 m depth), located in the southwest coast of India from April to November 2016, is described based on size-fractionated phytoplankton biomass (chlorophyll a), primary production and community composition. The study region exhibited well-distinct spatio-temporal hydrological changes because of the influence of wind-driven coastal upwelling, prevalent during the southwest monsoon (SWM) period. However, the formation of mud banks, in addition to coastal upwelling, was observed at station M2, which facilitated the substantial increase of water column turbidity and inorganic nutrients (ammonium, phosphate, and silicate) during and after the peak SWM period compared to the non-mud bank reference stations (M1 and M3). The prevailing hydrological changes were complemented the corresponding phytoplankton productivity patterns, in which profound domination of nanophytoplankton (2-20 µm) chlorophyll a and primary production was observed throughout the study region, irrespective of seasons. The SIMPER analysis, based on phytoplankton (mostly >20 µm) species composition data (microscopy), revealed the formation of certain characterizing species, mainly comprised of diatoms and dinoflagellates. The consistent predominance of the nanophytoplankton, established under variable hydrological scenarios, showed that the inorganic nutrient (specifically ammonium) availability was instrumental in defining the widespread growth of nanophytoplankton community compared to the prevailing light levels. The present study thus revealed that even the small-sized phytoplankton community could survive in the nutrient-enriched coastal waters, characterised by the co-existing upwelling and mud banks.

16

Performance evaluation of non-water absorption coefficient partitioning algorithms in optically complex coastal waters of Kochi and Goa, India

Kolluru Srinivas, Gedam Shirishkumar S., Inamdar Arun B.

Oceanologia

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2021

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No. 63 (4)

420--437

EN

Absorption coefficient partitioning algorithms (APAs) were developed to partition the total absorption coefficient (a(λ)) or total non-water absorption coefficient (anw(λ)) into the absorption subcomponents, i.e., absorption due to phytoplankton aph(λ), colored dissolved organic matter (CDOM) aƍ(λ) and non-algal particulate matter ad(λ), λ is the wavelength. Absorption coefficients of CDOM and non-algal particulate matter are generally combined due to a similarity in exhibited spectral shape and represented as colored detrital matter (CDM) absorption coefficient, adƍ(λ). This study focuses on the applicability of five APAs Schofield's, Lin's, Zhang's, Stacked Constraints Model (SCM) and Generalized Stacked Constraints Model (GSCM), in deriving the absorption subcomponents from anw(λ) in optically complex coastal waters of Kochi and Goa, India. The average spectral Mean Absolute Percentage Errors (MAPE) obtained for all models in the retrieval of aph(λ), ad(λ), aƍ(λ) and adƍ(λ) lie in the ranges of 26-44%, 37-45%, 34-65% and 42-56%. Slopes of adƍ(λ), aƍ(λ) and ad(λ) as indicated by Sdƍ, Sƍ and Sd are derivable from GSCM, Schofield and Lin's models only. GSCM model exhibited good retrieval capability of Sd with MAPE values of 22% and a correlation coefficient of 0.74. In retrieval of Sƍ parameter, none of the models demonstrated satisfactory performance. Overall, the GSCM and Schofield's models demonstrated good performance in the retrieval of absorption subcomponents, aph(λ), adƍ(λ), ad(λ) and Sd. Effect of applying baseline correction to ad(λ) on model performance is studied. Tuning with in situ data can further improve the absorption subcomponent and slope parameter retrieval capability of the models.

17

Characterization of phytoplankton size-structure based productivity, pigment complexes (HPLC/CHEMTAX) and species composition in the Cochin estuary (southwest coast of India) : special emphasis on diatoms

Paul Meenu, Velappan Madhu Nikathithara, Nanappan Ullas, Gopinath Vineetha, Velloth Rehitha Thekkendavida, Rajendran Ashwini, Nair Maheswari, Peariya Anil

Oceanologia

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2021

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No. 63 (4)

463--481

EN

Seasonal studies on size-fractionated phytoplankton productivity (biomass and primary production), marker pigments, and species composition and abundance were carried out in the Cochin estuary (CE), located on the southwest coast of India, to identify the critical environmental factors that control the consistent preponderance of diatoms. The overall results of the study showed a significant contribution of small-sized phytoplankton, specifically nanophytoplankton (2-20 µm), to the total chlorophyll a and primary production in the estuary, regardless of seasons. Diatoms constituted the major phytoplankton taxa, showed an exceptional seasonal scale increase in numerical abundance during the post-southwest monsoon. The relative increase in fucoxanthin (biomarker of diatoms) over other marker pigments substantiated the numerical dominance of diatoms throughout the sampling periods. This is the first study in the CE in which phytoplankton marker pigments have been detected and elucidated the seasonality of functional groups based on HPLC/chemotaxonomy analytical approaches. The prevalence of high DiatDP and diatom chlorophyll a equivalent (estimated by CHEMTAX), further confirmed the preponderance of diatoms in the CE, despite the intermittent dominance of cyanophytes and cryptophytes (monsoon period). The consistent increase in SPM levels (> 25 mg L–1), established at all sampling stations, indicated that the water column turbidity might be one of the significant environmental factors hindering the growth of large-sized phytoplankton (ca. >20 µm) in the CE even if the system invariably holds high inorganic nutrients, irrespective of seasons.

18

Physico-chemical and biological water quality of Warna and Pengilon Lakes, Dieng, Central Java

Soeprobowati Tri Retnaningsih, Addadiyah Nurul Layalil, Hariyati Riche, Jumari Jumari

Journal of Water and Land Development

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2021

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no. 51

38--49

EN

Warna and Pengilon Lakes are very close to each other and connected with the sill, a famous tourist destination in the Dieng Plateau Java. Land-use changes are the main problem that affected the lakes. The conversion of forest into an agricultural area had induced erosion and increased the volume of nutrients discharged to the lake due to high use of fertilisers in potatoes farms. In the dry seasons, water from those lakes was pumped to irrigate agricultural land. This study aimed to determine the water quality of Warna and Pengilon Lakes based on physical, chemical parameters, and phytoplankton communities. Water samples were collected from 4 sites at each lake to analyse biological oxygen demand (BOD), chemical oxygen demand (COD), ammonia, nitrate, nitrite, and total nitrogen (TN). Temperature, pH, dissolved oxygen (DO), turbidity, and conductivity (EC) were measured in-situ. During this research, turbidity and BOD in Warna and Pengilon Lakes exceeded the Indonesian water quality standard. Based on the STORET method, the water quality of Lake Warna was assessed as highly polluted for all classes. However, based on the pollution index (PI), Lake Warna was slightly to moderately polluted, as well as the saprobic index was in the β-mesosaprobic phase. Based on the species diversity index of phytoplankton, both Warna and Pengilon Lakes were moderately polluted. The long-term monitoring studies are necessary as an early warning sign of water quality degradation. Therefore, they provide insight into the overall ecological condition of the lake and can be used as a basis for developing suitable lake management.

19

Key Species of Phytoplankton in Eastern Part of Segara Anakan Indonesia Based on Season

Piranti Agatha Sih, Setyaningrum Nuning, Widyartini Dwi Sunu., Ardli Erwin Riyanto

Journal of Ecological Engineering

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2021

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Vol. 22, nr 3

135--142

EN

Phytoplankton blooms are a problem that often occurs in estuarine and coastal ecosystems. The changes in phytoplankton community species composition, diversity, biomass, and distribution were caused by the conditions of seasonal and temporal variation. The immediate location of the estuary ecosystem is near cities, where rapid economic growth and human activity tends to increase the pressure on the environment. The purposes of this research were to evaluate the seasonal and temporal variation and to determine the key species of phytoplankton in the eastern part of Segara Anakan which can cause a bloom based on season. The samples of phytoplankton were taken from 6 sites during April – September 2019 when the highest tide occurred during the dry and rainy seasons. The community structure were performed using primer software Ver 5 to find the similarity and / or differences of the phytoplankton community structure based on season. Simper analysis was used to determine key species (phytoplankton species) based on season and location. The community structure of phytoplankton in Segara chicks were composed by 5 divisions. During the dry season, Bacillariophyta was dominant (82%), whereas during the rainy season, Bacillariophyta (43%) and Chlorophyta (31%) and Cyanophyta (25%) were the dominant species. This study shows that the phytoplankton community structure in this estuary presents the environment conditions during the rainy season that increase the abundance of phytoplankton, especially of the species which may thrive into blooms. The most important species was Oscillatoria limosa that had the highest percentage of contribution.

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Long-term changes in phytoplankton and macrophyte communities in an eutrophic shallow reservoir and prospects for its restoration

Rusanov Alexander, Trifonova Irina, Ignatyeva Natalia, Pavlova Oksana

Oceanological and Hydrobiological Studies

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2020

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Vol. 49, No. 2

168--183

EN

Long-term changes in hydrochemistry and community structure of phytoplankton and macrophytes were analyzed in the Sestroretskiy Razliv reservoir (northwestern Russia). The average content of total phosphorus (TP) in May–October increased from 73 μg P l-1 in 1980 to 163 μg P l-1 in 2000. A significant increase in average chlorophyll a content from 16.6 μg l-1 in 1980 to 84.7 μg l-1 in 2000 and a shift in phytoplankton composition to the dominance of cyanobacteria over diatoms indicated a change in the trophic status of the reservoir from meso-eutrophic to hypertrophic. In 2016 and 2018, average TP was 96 and 101 μg P l-1, respectively. The average content of chlorophyll a was 43.6 μg l-1 in 2016 and 66.6 μg l-1 in warmer 2018, indicating persistent eutrophic conditions. Diatoms dominated both in 2016 and 2018, especially in 2016 characterized by unfavorable weather conditions. Cyanobacteria were more abundant in 2018 with higher summer temperatures. The decline of the total area covered by aquatic vegetation from 157 ha in 1980 to 76 ha in 2016 likely resulted from an increase in phytoplankton biomass and water turbidity. Based on the results of our observations, in addition to further reduction in nutrient loading, biomanipulation by introducing predatory fish as a restoration measure was proposed to improve the ecological status of the reservoir.