Phytoplankton Diversity Research Articles

Composition, Density and Diversity of Phytoplankton in Rathi Cheruvu, Bhadradri Kothagudem, Telangana, India

The current study deals with composition, density and diversity of phytoplankton during January 2023 to December 2023 monthly in the Rathi cheruvu, Bhadradri Kothagudem, Telangana, India. Samplings were collected from different locations of the study site during a one year research period. Several physico-chemical parameters were studied from two sampling stations such as water temperature, pH, DO, BOD, SO4, NO3, PO4 and Cl-, of which pH, DO and BOD were shown to be the most significant in growth and development of phytoplanton. In the current study revealed a total number of 43 species of phytoplankton belonging to four major classes i.e. Chlorophyceae with 16 species, Bacillariophyceae with 14 species, Euglenophyceae with three species and Cyanophyceae with 10 species. The maximum population of phytoplankton diversity was observed during summer followed by monsoon with a total 1058 phytoplankton species during one year of study period. Finally the study showed that the study site has a well balanced phytoplankton community.

Sedimentary DNA reveals phytoplankton diversity loss in a deep maar lake during the Anthropocene

AbstractAnthropogenic‐driven environmental change, including current climate warming, has influenced lake ecosystems globally during the Anthropocene. Phytoplankton are important indicators of environmental changes in lakes and play a fundamental role in maintaining the functioning and stability of these ecosystems. However, the extent to which lake phytoplankton were affected by anthropogenic or climatic forces during the Anthropocene remains unclear. Here, we investigated the 160‐yr‐long dynamics of the phytoplankton community (cyanobacteria and eukaryotic microalgae) in response to anthropogenic forcing in Sihailongwan Maar Lake—a candidate for a Global boundary Stratotype Section and Point for demarcation of the Anthropocene—using DNA metabarcoding and traditional paleolimnological approaches. Our results show a significant decline in phytoplankton diversity and an abrupt shift in community composition around the 1950s, corresponding to the beginning of the “Great Acceleration” period. Specifically, phytoplankton taxa coexistence patterns, niche differentiation, and assembly mechanisms changed significantly after the 1950s. Overall, increases in air temperature and anthropogenic forcing appear to be the dominant controls for community reorganization and diversity decline of the phytoplankton from this deep maar lake. A neutral community model suggests that phytoplankton community composition was mainly controlled by stochastic processes before the 1950s; however, as time progressed, deterministic effects driven by anthropogenic global warming increased. The results of this study imply that anthropogenic perturbations have led to a loss of phytoplankton diversity and a further decline in ecological resilience in deep lakes, with likely knock‐on effects on the productivity and function of lake ecosystems.

Optical characteristics of dissolved organic matter in relation to phytoplankton in Lake Erhai, China

Dissolved organic matter (DOM), as the primary form of organic carbon in lakes, is crucial for the lake carbon cycling. As an important component of lake ecosystems, phytoplankton plays a crucial role in carbon fixation. However, we are not yet clear about the contribution of phytoplankton composition to DOM. To clarify this issue, we conducted we conducted continuous monitoring for 6 months in Lake Erhai, a plateau lake in China. Through quantitative detection of phytoplankton and spectral characteristic analysis, four fluorescence components were identified: tryptophan-like (C1), tyrosine-like (C2), fulvic-like (C3), and humic-like (C4). The Fluorescence Index (FI) ranged from 1.70 to 2.54, and the Biogenic Index (BIX) was above 0.8, indicating the DOM in Lake Erhai’s overlying water was predominantly autochthonous. Cyanophyta prevailed in September and November, while Chlorophyta dominated in other months. Phytoplankton diversity was significantly related to DOM concentration that may be related to the difference in the DOM contribution of different phytoplankton. The effect of phytoplankton biomass on C3 and C4 was prominent. Whereas, phytoplankton did not stimulate C1 and C2 significantly, indicating that protein-like may originate from terrestrial input and microbial activity. The composition of phytoplankton significantly affects the DOM composition in Lake Erhai. Therefore, the autochthonous DOM production by phytoplankton warrants further consideration in plateau lake systems.

Eksplorasi Limnologis Telaga Dringo, Banjarnegara, Jawa Tengah

Plankton are organisms that live floating in water bodies and move with the current. Plankton is a clue organism that can be used as a bioindicator because it is sensitive to environmental changes. The purpose of this study was to explore the limnological aspects of plankton distribution and diversity as bioindicators of water quality. In this study, 29 species of phytoplankton and 20 species of zooplankton were obtained, dominated by Nitzschia sp. and Asplanchna sp. The abundance index showed that the abundance of phytoplankton was 19386.67 ind/L and zooplankton was 5.33 ind/L. Water status based on phytoplankton diversity index with a value of 0.28-1.00 is categorized as low diversity and zooplankton diversity with a value of 0.78-1.97 is categorized as moderate diversity.

Phytoplankton Diversity as a Bioindicator for Water Quality of Pertamina Harbour Ampenan, Lombok

Ampenan district is an area that has a fairly high population density. There are community activities such as selling on the beach, littering, tourism activities and crossing activities at the Pertamina Harbour Ampenan which can cause a decrease in water quality. This research was conducted to determine water quality of Pertamina Harbour Ampenan based on phytoplankton community. Sea waters samplings were carried out using a 20µm plankton net. Observation and identification of phytoplankton was carried out in advances biology laboratory, FMIPA, Mataram University using a binocular microscope. Phytoplankton data were analyzed based on the abundance, diversity, dominance and saprobity index. The results of this research showed that the phytoplankton community of the Pertamina Harbour Ampenan waters consisted of 106 species from 6 classes with an abundance value of 4324,455 ind/L. Spesies diversity and dominant indexs of phytoplankton, and saprobic indexes of the Pertamina Harbour Ampenan waters were 1,767, 0,451 and 2,56 respectively. Based on the phytoplankton species diversity index, the waters of Pertamina Harbour Ampenan was categorized as moderately polluted, whereas saprobity index the waters of Pertamina Harbour was categorized as oligosaprobic.

Integrated evaluation of the impact of water diversion on water quality index and phytoplankton assemblages of eutrophic lake: A case study of Yilong Lake

Water diversion has been widely utilized to enhance lake water quality and mitigate cyanobacterial blooms. However, previous studies have mainly focused on investigating the effects of water diversion on water quality or aquatic ecological health. Consequently, there is limited research investigating the combined impact of water diversion on the water quality and the ecological health of eutrophic lakes, and whether the WQI and phytoplankton assemblages demonstrate similar patterns following water diversion. In this study, the effects of water diversion on the ecosystem health of eutrophic lakes were comprehensively evaluated based on the WQI indices and phytoplankton assemblages during the NWDP-21 and WDP-22. The results showed that the annual mean of WQI increased from 52.02 to 54.36 after water diversion, which improved the water quality of the lake, especially NH3–N and TN decreased by 58.6% and 15.2%, respectively. The phytoplankton assemblages changed significantly before and after water diversion, and we observed that the total biomass of phytoplankton decreased by 12.3% and phytoplankton diversity indices (Shannon-Wiener diversity, Pielou evenness, and Simpson index) increased by 8.6%–8.9% after water diversion, with an improvement in the connectivity and stability of the phytoplankton. Notably, enhanced adaptations of rare sub-communities for resource use in water diversion environments, and water diversion inhibited the dispersal ability of dominant functional groups, and the effects of hydrological disturbances on the structure of phytoplankton assemblage favored the ecological health of eutrophic lakes. VPA analysis further reveals that water diversion alters the drivers of phytoplankton functional group biomass and phytoplankton diversity. The results of the PLS-PM analysis clarify that water diversion indirectly impacts the total phytoplankton biomass and phytoplankton diversity primarily by modifying light availability. Significant correlations are observed between the dominant functional groups biomass and diversity indices of WQI. The trends in changes observed in water quality indices and phytoplankton following water diversion align with the evaluation of water ecological health. This study provides valuable guidance for the ecological management of the diversion project in Yilong Lake and serves as a reference for similar projects in other lakes.

Enhancing water quality and ecosystems of reclaimed water-replenished river: A case study of Dongsha River, Beijing, China

The use of reclaimed water for urban river replenishment has raised concerns regarding its impact on water quality and aquatic ecosystems. This study aims to reveal the improvements seen in an urban river undergoing a practical water eco-remediation after being replenished with reclaimed water. A one-year monitoring of water quality, phytoplankton, and zooplankton was carried out in Dongsha River undergoing eco-remediation in Beijing, China. The results showed that compared to the unrestored river, the concentrations of COD, NH4+-N, TP, and TN decreased by 28.22 ± 7.88 %, 40.24 ± 11.77 %, 44.17 ± 17.29 %, and 28.66 ± 10.39 % in the restoration project area, respectively. The concentration of Chlorophyll-a in the restoration area was maintained below 40 μg/L. During summer, when algal growth is vigorous, the density of Cyanophyta in the unrestored river decreased from 46.84 × 104cells/L to 16.32 × 104cells/L in the restored area, while that of Chlorophyta decreased from 41.61 × 104cells/L to 11.87 × 104cells/L, a reduction of 65.16 % and 71.47 %, respectively. The dominant phytoplankton species were replaced with Bacillariophyta, such as Synedra sp. and Nitzschia sp., indicating that the restoration of aquatic plants reduces the risk of Cyanophyta blooms. Zooplankton species also changed in the restoration area, especially during summer. The density of pollution-tolerant Rotifer and Protozoa decreased by 31.06 % and 27.22 %, while the density of clean water indicating Cladocera increased by 101.19 %. We further calculated the diversity and evenness index of phytoplankton and zooplankton within and outside the restoration area. The results showed that the Shannon-Weaver index for phytoplankton and zooplankton in the restoration area was 2.1 and 1.91, which was higher than those in the river (1.84 and 1.82). This further confirmed that aquatic plant restoration has positive effects. This study can provide a practical reference and theoretical basis for the implementation of water ecological restoration projects in other reclaimed water rivers in China.

Modeling time-varying phytoplankton subsidy reveals at-risk species in a Chilean intertidal ecosystem

The allometric trophic network (ATN) framework for modeling population dynamics has provided numerous insights into ecosystem functioning in recent years. Herein we extend ATN modeling of the intertidal ecosystem off central Chile to include empirical data on pelagic chlorophyll-a concentration. This intertidal community requires subsidy of primary productivity to support its rich ecosystem. Previous work models this subsidy using a constant rate of phytoplankton input to the system. However, data shows pelagic subsidies exhibit highly variable, pulse-like behavior. The primary contribution of our work is incorporating this variable input into ATN modeling to simulate how this ecosystem may respond to pulses of pelagic phytoplankton. Our model results show that: (1) closely related sea snails respond differently to phytoplankton variability, which is explained by the underlying network structure of the food web; (2) increasing the rate of pelagic-intertidal mixing increases fluctuations in species’ biomasses that may increase the risk of local extirpation; (3) predators are the most sensitive species to phytoplankton biomass fluctuations, putting these species at greater risk of extirpation than others. Finally, our work provides a straightforward way to incorporate empirical, time-series data into the ATN framework that will expand this powerful methodology to new applications.

Littoral phytoplankton and zooplankton communities in a tropical reservoir: Pantabangan Reservoir, the Philippines

Abstract Littoral phytoplankton and zooplankton diversity are influenced by the water quality parameters and their trophic interactions. In the largest reservoir of the Philippines, this study examined the water quality and plankton community composition in the littoral zone across three sampling sites and four depths. Of the three sites, one is located near active fish cages, one near the mouth of a tributary and one near an outlet of an upstream dam. A total of 36 phytoplankton and 34 zooplankton taxa were identified, with most taxa belonging to Chlorophyta and Cyclopoida. The most abundant phytoplankton and zooplankton taxa were Aulacoseira and Microcyclops, respectively. The three most abundant phytoplankton (Aulacoseira, Oscillatoria, Volvox) were most positively correlated with the nutrient levels [total nitrogen (TN), total phosphorus (TP) and TN:TP ratio]. A significant interaction of sampling site and depth was recorded for the phytoplankton’s Shannon diversity index and community composition. The decreased zooplankton diversity amidst decreased phytoplankton diversity in the aquaculture site aligns with the effect of lowered resource heterogeneity on zooplankton. The increased phytoplankton diversity and decreased zooplankton density and taxon richness at shallower depths were probably linked with the light availability.

Phytoplankton abundance and biodiversity in adjacent estuaries: the importance of submarine groundwater discharge

A near-unique pair of adjacent bays in the karst region of western Ireland provided the opportunity to compare phytoplankton diversity and abundance in an area of submarine groundwater discharge (SGD) side by side with a ‘control’ region of similar size and with the same marine influences. Freshwater input to Kinvara Bay comes from the surrounding karst hinterland via a subterranean groundwater network, emerging at several sites within the inner bay as submarine groundwater discharge (SGD). Aughinish Bay in contrast has no connection to a SGD network and negligible overground fresh water input. Sampling was carried out in both bays during spring and neap tides over Winter, Spring/Summer and Summer/Autumn of 2016 and 2017. Comparison of the phytoplankton communities in the two bays showed higher diversity in Aughinish, while a bloom of Prorocentrum micans (Ehrenber, 1834), a brackish-water-tolerant marine dinoflagellate, was observed only in Kinvara. This work demonstrates how SGD can control phytoplankton community structure even in well-flushed macro-tidal bays and thus controls the biogeography at local scales.

Water Quality Assessment of Bibinagar Lakeby Physico-Chemical Parameters

This study investigated the seasonal variations in physico-chemical parameters and their impact on phytoplankton diversity, community structure, and abundance in Bibinagar Lake from May 2021 to April 2022. Key parameters analyzed included temperature, turbidity, pH, electrical conductance, total dissolved solids (TDS), total hardness, dissolved oxygen (DO), biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Significant seasonal fluctuations were observed, with temperature ranging from 16.2°C to 18.8°C, turbidity peaking during monsoon runoff, and variations in pH, conductance, and hardness. Elevated BOD and COD levels in late months indicated increased organic pollution. Despite these fluctuations, most parameters stayed within normal ranges, suggesting generally good water quality. The study underscores the dynamic nature of water quality and highlights the importance of continuous monitoring to manage pollution and protect aquatic ecosystems.

Phytoplankton Composition in Waters Around Hot Water Waste of Steam Electricity Power Plant Nii Tanasa

Understanding the complex dynamics of aquatic ecosystems is very important for sustainable resource management in the field of aquatic resource management studies. This study aims to determine the distribution, abundance and diversity of phytoplankton and its correlation with water temperature around the PLTU Nii Tanasa area. The sampling method used is purposive sampling by taking water samples using a plankton net at predetermined stations. Data analysis of abundance, diversity, dominance, and correlation using Microsoft excel software. The number of samples found was 12 types of phytoplankton and came from several different classes. Abundance index (N) = low-moderate fertility (low enough), diversity index (H) = moderate category, dominance (C) = low, indicating stable community structure conditions. Water quality is classified as waters with moderate levels of pollution. Correlation of abundance, diversity and dominance of phytoplankton with water temperature has a positive and negative linear relationship.

Phytoplankton Dynamics in an Oligo-mesotrophic Environment along the Montenegrin Coast (South-East Adriatic Sea)

The dynamics of the phytoplankton community were studied along the Montenegrin coast, in the mesotrophic area of Boka Kotorska Bay and the oligotrophic coastal open sea area. This two year study investigates differences in dynamics of phytoplankton assemblages and abundances in the Bay area, which is highly impacted from the land, and the open coastal part of the Montenegrin coast, which is highly influenced by Levantine water masses but less affected by anthropogenic influence.` Regarding phytoplankton diversity, the microplankton species detected are those that prefer areas rich in inorganic nutrients, such as Chaetoceros affinis, Dactyliosolen fragilissimus, Leptocylindrus danicus, Pseudo-nitzschia spp., and Thalassionema nitzschioides. These species used both new and regenerated nutrients which regenerated at each grazing level of the microbial loop and are thus made available to the primary producers. The potentially toxic Pseudo-nitzschia spp. reached an abundance of 105 cells/L. Among the potentially toxic dinoflagellates, Dinophysis acuminata, D. acuta, D. caudata, D. fortii, D. tripos, Gonyaulax spinifera, Lingulodinium polyedra, Phalacroma rotundatum were recorded (the abundance reached values up to 102 cells/L). The detected presence of several potentially toxic and toxic phytoplankton species warrants the need to raise awareness for the necessity of continuous monitoring activities and preventive measures.

Spatial and Temporal Variability in Water Quality and Phytoplankton Community Composition in Charleston Harbor

The Charleston Harbor estuary is a dynamic ecosystem draining three rivers that surround the rapidly urbanizing greater Charleston area. Projected climate change impacts include elevated sea surface temperature and local changes in water quality that will likely alter biogeochemical cycling as well as phytoplankton abundance and community composition. Partnering with the local non-profit organization Charleston Waterkeeper, surface water samples were collected from late April through October 2021 at 20 sites in the Charleston Harbor estuary system. Water quality parameters measured included sea surface temperature (SST), salinity, pH, dissolved inorganic carbon, chromophoric dissolved organic matter (CDOM), phytoplankton pigments and nitrate and phosphate concentrations. Relatively high (6—16 μM) nitrate values were observed throughout the year and the nitrate to phosphate (N:P) ratios were consistently elevated (50—200) relative to the Redfield ratio of 16. Analysis of variance indicated that the delivery of nitrate, phosphate, and CDOM into the estuary came from upriver of the Charleston Harbor. For instance, CDOM was significantly impacted by tidal stage (p < 0.05) and was negatively correlated with salinity at low salinity sites, but no correlation was observed at high salinity sites. Seasonal patterns in phytoplankton community abundance and composition were driven by changes in SST, as overall phytoplankton biomass increased with a community shift from diatoms during colder months to flagellated cells such as prasinophytes during the warmer summer months. Phytoplankton diversity was greatest during the early summer and lowest in October. This study provides a reference baseline for water quality parameters and phytoplankton community composition in an estuarine ecosystem that is changing rapidly due to dredging and climate change processes.

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.

Water quality and habitat drive phytoplankton taxonomic and functional group patterns in the Yangtze River

BackgroundAlthough phytoplankton are important primary producers in food webs, they are relatively less studied in large rivers compared to other types of systems. To fill this research gap, we studied phytoplankton taxonomic and functional composition and their relationships with water quality, habitat, climate, and land use across 30 river sections in the middle and lower reaches of the Yangtze River during 2017–2018.ResultsMajor observed phytoplankton groups were cyanobacteria, bacillariophyta, and chlorophyta. Phytoplankton total abundance, total biomass, and species richness significantly decreased in the dry season compared to the wet season, with the species and functional composition differing significantly between seasons. Phytoplankton species differences between seasons were mainly contributed by Oscillatoria sp., Pseudanabaena sp., and Melosira granulata. The dfferences in phytoplankton functional groups between seasons were mainly contributed by P (including Closterium sp., Melosira sp.), Lo (including Merismopedia sp., Peridinium sp., Ceratium sp., and Gymnodinium sp.), and J (including Pediastrum sp., Tetraedron sp., Crucigenia sp., Scenedesmus sp., and Coelastrum sp.). The variance partitioning showed that water quality (NO3-N, total suspended solids, turbidity) and habitat (water flow, river bank and river channel conditions) were critical factors in shaping phytoplankton patterns, followed by climate and land use.ConclusionsResults indicated that there was significant seasonal variation of phytoplankton in the Yangtze River, with water quality and habitat primarily driving phytoplankton patterns. Our study contributes to the understanding of natural and anthropogenic factors that drive seasonal successional processes of phytoplankton in the Yangtze River. These findings have important implications for environmental management as well as towards the ecological restoration of large rivers.

Environmental driving forces and phytoplankton diversity across the Ross Sea region during a summer–autumn transition

AbstractThe Ross Sea is a highly productive system characterized by a seasonal succession of phytoplankton groups. However, most of the current understanding is based on observations on the continental shelf in spring and summer at relatively coarse taxonomic resolution. Here, we characterize community composition (class to species) using V4‐18S rRNA gene metabarcoding on transects to and across the Ross Sea (shelf‐slope and oceanic subregions) during two voyages covering the Austral summer–autumn progression in successive years. Phytoplankton composition shifted from low‐diversity diatom‐dominated (50%) communities during the summer to more diverse dinoflagellate‐dominated (48%) systems during the lower‐productivity autumn season. Prymnesiophyceae abundance was low on both voyages (10%), except on the southeast shelf‐slope, where Phaeocystis antarctica dominated a shallow mixed layer, contrary to its reported preference for deep‐mixing conditions. Amplicon sequence variant analysis identified distinct spatial patterns for two P. antarctica genotypes yet clustered certain species of Bacillariophyta and Prymnesiophyceae, indicating similar environmental preference for genotypes in these groups. Multivariate analysis of environmental drivers found a higher correlation of community composition variation with salinity and macronutrients, but less so with mixed layer depth, considered a primary determinant of taxonomic composition in the Ross Sea. Comparison between years established that community composition was temporally more stable in oceanic relative to shelf‐slope waters. This study of seasonal variation of phytoplankton community composition at finer taxonomic resolution provided insights into species‐ and strain‐specific distribution, ecological preferences, and relationships to environmental conditions in the wider Ross Sea to inform modeling and projection of future regional changes.

Spatio-temporal dynamics of phytoplankton diversity and community structure in relation to environmental variables in the Northwest Coasts of India

Spatio-temporal dynamics of phytoplankton diversity and community structure in relation to environmental variables in the Northwest Coasts of India

Rapid variations of phytoplankton blooms and their dynamics off the Changjiang River Estuary

Phytoplankton frequently blooms in estuaries and coastal seas. Numerous dynamic processes affect these regions, generating complex hydrodynamics that induce intense phytoplankton variability over multiple time scales. Especially, the variability over time scales of 100-101 days (event-scale) is a strong signal that is fundamental to coastal aquatic environments and ecosystems. Based on the historical monitoring of harmful algal bloom events and a fully coupled hydrodynamics-sediment-ecosystem numerical model, this study explored horizontal distribution patterns of the phytoplankton maximum off the Changjiang River Estuary over multiple time scales. Our results showed that the bloom events typically lasted less than a week and horizontal distribution of the horizontal chlorophyll maximum varied over the time scale of days. Tidal forcing was shown to dominate the periodic phytoplankton variability. The variations of river runoff and wind forcing also modulated this variability and added more disturbances. Increased runoff and enhanced summer monsoon wind caused the horizontal chlorophyll maximum to physically extend further offshore, while they also biologically stimulated phytoplankton blooms. The analysis of the time scale showed that the regulation of horizontal chlorophyll maximum responds faster to physical effects than in biological ones. At the same time, during neap tides, the adjustment of phytoplankton to the disturbances associated with the hydrodynamic processes was stably salient. Such adjustment was based on the adaptation to light availability and nutrient supply. This study contributes to the understanding of phytoplankton variability in estuaries affected by multiple physical-biological processes over the time scale of days and benefits to the management of environmental conservation.

Phytoplankton Diversity as Bioindicator of Water Quality in Mangrove Area of Surabaya East Coast

Phytoplankton Diversity as Bioindicator of Water Quality in Mangrove Area of Surabaya East Coast