Zooplankton Diversity Research Articles

Diversity and seasonal variation of zooplankton community in a large deep-water reservoir of Eastern China using eDNA and morphological methods

Monitoring zooplankton diversity and community dynamics is essential for understanding ecological processes within freshwater ecosystems. Environmental DNA (eDNA) has been increasingly employed in this field due to its efficiency and accuracy. However, its potential applications in freshwater ecosystems require further validation. In this study, we evaluated the performance of 18S rRNA and COI primers for freshwater zooplankton diversity monitoring and systematically compared the selected primers with the microscopy method in Qiandao Lake, China. Our results indicated that the COI primer marker (mlCOIintF/jgHCO2198) was more suitable for freshwater zooplankton diversity monitoring than 18S rRNA. The eDNA method identified a total of 102 species, whereas the microscopy method detected 111 species. Non-metric multidimensional scaling (NMDS) analysis and nonparametric multivariate statistical tests revealed that both abundance and biomass species compositions determined by microscopy differed significantly from those based on eDNA reads. Both methods detected significant seasonal changes in zooplankton community species composition, while eDNA provided a comprehensive view of the complex interactions within the community. Both methods indicate that rotifers are the primary group driving seasonal changes in the zooplankton community. The eDNA identified more environmental factors associated with seasonal changes in zooplankton communities than microscopy, including dissolved oxygen (DO), nephelometric turbidity unit (NTU), ammonia nitrogen (NH3-N), and total phosphorus (TP). The eDNA reads of rotifer and crustacean plankton increased linearly with their morphological abundance but not with biomass. Furthermore, combining morphological abundance and biomass as predictor variables for eDNA reads moderately enhanced the explanatory power compared to using them individually. Although eDNA cannot yet replace morphological methods, its efficiency and sensitivity make it a valuable complementary tool for zooplankton monitoring, with considerable potential for future applications.

Plankton Community Structure in the Estuaries of Banten Bay, Banten Province, Indonesia

Estuaries in Banten Bay support fisheries activities by serving as critical habitats for plankton communities, which form the foundation of the aquatic food web. This study aims to determine the structure of plankton communities, both phytoplankton and zooplankton, as baseline data for fisheries management in Banten Bay estuaries. Fieldwork was conducted in April and October 2021 at four estuaries in Banten Province: Karangantu, Wadas, Cengkok Estuary, and Pamong. Water samples were collected for plankton identification and analysis of physical and chemical water quality parameters in situ and laboratory. Key structural attributes, including Shannon - Wiener diversity index (H'), evenness index (E), dominance index (C), trophic status and canonical correspondence analysis (CCA), were also assessed. The highest abundance of phytoplankton was found in the Karangantu estuary, while the highest abundance of zooplankton was observed in the Pamong estuary, with overall abundance higher in April. Phytoplankton diversity was highest in Karangantu in October, whereas zooplankton diversity peaked in April. Plankton diversity indicated slight to moderate pollution levels, and trophic status analysis revealed eutrophic to hypertrophic conditions across the estuaries, suggesting high nutrient levels that support fish productivity. CCA revealed significant correlations between environmental variables and plankton composition and abundance. Mitigation strategies are recommended to monitor the growth of Chaetoceros sp. and Bacteriastrum sp., especially during the dry season. Long-term monitoring of water quality and plankton dynamics is essential in other estuaries of Banten Bay to assess nutrient loading impacts and develop strategies to mitigate harmful algal blooms. These efforts are critical to ensuring sustainable fisheries management in the region.

DNA in Lake Sediment Reveals the Impact of Introduced Fish

Non-native trout have altered the diversity of zooplankton that live in high-elevation lakes.

Variability of Zooplankton in Two Neighboring Tropical High-Mountain Lakes

Variability of Zooplankton in Two Neighboring Tropical High-Mountain Lakes

STRUKTUR KOMUNITAS PLANKTON DI DANAU BATUR, KECAMATAN KINTAMANI, PROVINSI BALI

Plankton is the most important component of aquatic life and plays an important role in the food chain. Plankton is divided into two, namely animal plankton called zooplankton and plant plankton called phytoplankton. This research aims to determine the plankton community structure and water quality parameters in Lake Batur, Kintamani District, Bali Province. The research was conducted in January-March 2024 at Lake Batur. The research method used was a quantitative descriptive method. The sampling technique used was the purposive sampling method. The identification results show that there are 4 classes of phytoplankton, namely Bacillariophyceae, Cyanophyceae, Euglenophyceae and Chlorophyceae. The phytoplankton abundance value is in the range of 1.943-6.568 ind/L, the average diversity index value is 1.030, the average uniformity index value is 0.391, the average dominance index value is 0.461 so it is included in oligotrific and mesotrific waters. The results of zooplankton observations found 4 classes containing 5 genera, namely Branchiopoda, Ostracoda, Maxillopoda and Lobosea. The average value of zooplankton abundance ranges from 35-145 ind/L, the average value of the zooplankton diversity index is 1.388, the average value of the zooplankton uniformity index is 0.863, the average value of the zooplankton dominance index is 0.289, so it is included in the mesotrophic waters category. The results of observations of chemical and physical parameters obtained an average value of temperature of 27-28oC, brightness of 4-5 m, pH of 8.5, DO of 6.53-6.73 mg/L, nitrate of 0.41- 0.938 mg/L, and phosphate, namely 0.705-0.111 mg/L. The water quality conditions in Lake Batur show that the waters are still suitable for plankton growth. Keywords: Lake Batur; Water quality; Plankton Community Structure

Ecology and diversity of zooplanktons in an aquaculture pond of Madhepura

Present study was conducted in an aquaculture pond of Madhepura town. Physicochemical parameters of water studied. Altogether, 11 genera of zooplanktons were identified belonging to 8 families. Rotifera was represented by 4 families and 4 genera, Cladocera with two families and 3 genera and Copepoda with two families and 4 genera. Rotifera dominated throughout the year. Maximum population of Rotifera were found in winter season and minimum in rainy season. Cladocera population was largest in summer season and lowest in winter. Copepoda population was maximum in rainy season and minimum in winter season. Seasonal variation in abundance of zooplanktons was maximum in summer (152 ind/l) and minimum in rainy season (116 ind/l). Percentage population of Rotifera was recorded as 54.63%, that of Cladocera 26.80% and that of Copepoda 18.55%.. KEYWORDS :Zooplanktons, Abundance, Diversity, Rotifera, Cladocera, Copepoda.

Community-level responses and environmental fate of metformin in freshwater mesocosms.

The type 2 diabetes drug metformin is among the most frequently prescribed, dispensed, and consumed pharmaceuticals worldwide; and its heavy use and poor breakdown means it is consequently detected in various wastewater treatment plant (WWTP) effluents and surface waters. The resulting environmental concentrations of metformin can have adverse impacts on aquatic ecosystems. An 8-week in-lake mesocosm experiment was conducted in a freshwater boreal lake at the IISD-Experimental Lakes Area (Ontario, Canada) to determine the environmental fate and effects of metformin. Mesocosms were assigned to nominal concentrations of 0, 5, or 50μgL-1 metformin, in replicates of four. Biotic communities (i.e. microbial, phytoplankton, zooplankton, benthic macroinvertebrate) were assessed and complementary Lemna gibba and Daphnia magna bioassays were conducted in the laboratory. Metformin was extremely stable during the 8-week experiment, with mean measured concentrations of 0.00, 5.42, and 42.79μgL-1 in mesocosm surface waters for the 0, 5, and 50μgL-1 treatments, respectively. While trace amounts of metformin were detected in mesocosm sediments, the compound was primarily found in the water column. After over 1year following metformin additions, the mean loss of metformin from surface water was 94.0% and 91.0% for the 5 and 50μgL-1 treatment groups, respectively. No adverse effects of metformin treatment on the diversity, abundance, or biomass of microbial, phytoplankton, zooplankton, or benthic macroinvertebrate communities were found. Additionally, no survival or reproductive effects were observed in the 21-d Daphnia magna bioassays and no significant effects were observed in the 7-d Lemna gibba growth assays. No substantial metformin transformation to guanylurea was observed in mesocosm surface waters or sediments, likely due to a lack of bacterial degradation occurring within mesocosms relative to WWTPs.

Studies on changes in blood glucose in Prometon (weedicide) induced fresh water fish, Mystus bleekeri (day)

Zooplankton, the microscopic and free-swimming animal component of an aquatic ecosystem plays an important role on its energy flow process. From the fishery point of view, zooplankton forms the vital links in the pelagic food chain. Many micro zooplanktons also constitute the major food items of the larvae of crustaceans, molluscs and fishes. Thus, abundance of zooplankton practically acts as an ideal index to assess the fertility of given water mass. The present study deals with the quantitative and quantitative diversity of zooplankton in Chilika lagoon. Four zooplankton group viz.,Copepoda, Protozoa, Cladocera and Rotifera were recorded. Theabundance of zooplankton during the sampling period varied between 1775-4840 u/l. Pre-monsoon registered highest abundance (4675-4217 u/l) with average value (2223 u/l) followed by post-monsoon (u/l) with average value 2047 u/l and monsoon (1775-3522nos/m-3) with an average value 1324nos m-3. Copepods had emerged as the most dominant group (57%) throughout the study period. The shared group followed by protozoa (19%), cladocera (14%) and rotifera (10%).. KEYWORDS :Chilika, Zooplankton, Diversity, Abundance.

Diversity and abundance of zooplankton in chilika lagoon, Odisha

Zooplankton, the microscopic and free-swimming animal component of an aquatic ecosystem plays an important role on its energy flow process. From the fishery point of view, zooplankton forms the vital links in the pelagic food chain. Many micro zooplanktons also constitute the major food items of the larvae of crustaceans, molluscs and fishes. Thus, abundance of zooplankton practically acts as an ideal index to assess the fertility of given water mass. The present study deals with the quantitative and quantitative diversity of zooplankton in Chilika lagoon. Four zooplankton group viz.,Copepoda, Protozoa, Cladocera and Rotifera were recorded. Theabundance of zooplankton during the sampling period varied between 1775-4840 u/l. Pre-monsoon registered highest abundance (4675-4217 u/l) with average value (2223 u/l) followed by post-monsoon (u/l) with average value 2047 u/l and monsoon (1775-3522nos/m-3) with an average value 1324nos m-3. Copepods had emerged as the most dominant group (57%) throughout the study period. The shared group followed by protozoa (19%), cladocera (14%) and rotifera (10%).. KEYWORDS :Chilika, Zooplankton, Diversity, Abundance.

Navigating the Zooplankton Realm: Oceans of Diversity Beneath the Sea Surface

This review provides a comprehensive summary of the current knowledge on marine zooplankton diversity and distribution, highlighting key advancements and future directions in the field. While the approach used in this review is necessarily broad, focusing on overarching trends and drivers of zooplankton diversity, it emphasizes recent methodological innovations. The review begins with an introduction to zooplankton, tracing the historical development of their research. It then explores the critical roles zooplankton play in ocean ecosystems, climate change, and the global economy. Next, the review examines the environmental and anthropogenic factors influencing marine zooplankton. Finally, it presents a comparison between marine and freshwater zooplankton and concludes with a discussion of the challenges facing current zooplankton diversity research and the presentation of possible directions and implementation strategies for advancing the understanding of zooplankton biodiversity and ecology.

Modular shadowgraph imaging for zooplankton ecological studies in diverse field and mesocosm settings

AbstractVarious iterations of shadowgraph imaging have been used to quantify zooplankton in situ with high spatial resolution. Because these systems can image relatively large volumes of water, they are especially useful for resolving less common meso‐ or macrozooplankton taxa (< 50 ind. m−3), such as larval fishes and gelatinous animals. However, larger volume imagers are typically integrated with heavy towed vehicles and deployed from research vessels, which introduces high costs and limits sampling approaches. Here we demonstrate that versatile configurations of shadowgraph imaging, including modular benchtop, handheld, and towed, compact vehicle systems (along with customizable software), allow for tailoring sampling to a variety of marine and freshwater settings (including mesocosms). These systems encompass a suite of possible architectures, designed for adapting the imaging depth of field, acquisition rates, sensor configuration, and deployment method to fit a wide range of sampling protocols, with high vertical resolution (~ 5 cm) and adequate taxonomic capabilities for > 0.5 mm organisms. The benchtop system facilitates an interactive approach to observe and quantify zooplankton behaviors and optical properties. Video footage from the benchtop system generates thousands of regions of interest min−1 for target organisms with variable orientations and swimming postures. When used in conjunction with in situ imaging, the benchtop system can build large machine learning training libraries targeted toward rare or morphologically diverse zooplankton, which often includes the larval stages of economically valuable taxa. These modular hardware and software components increase affordability and versatility while broadening the scope of scientific questions addressed by plankton imaging systems.

Species Composition and Diversity of Zooplankton in Chackferi Stream, Tarai Region, Uttarakhand, India

Present study deals with the analysis of species composition and diversity of zooplankton in Chackferi stream. For this investigation samples were collected by monthly intervals for a period of September 2020 to August 2022. A total of 28 species of zooplankton, belonging to 25 genera across 5 groups were identified such as Protozoa (6 species of 6 genera), Rotifera (10 species of 9 genera), Copepoda (7 species of 5 genera), Cladocera (3 species of 3 genera) and Ostracoda (2 species of 2 genera). Rotifera was the dominant group, comprising (36%) of the zooplankton community in Chackferi stream, followed by Copepoda (25%), Protozoa (21%), Cladocera (11%) and Ostracoda (7%). It was noticed that seasonal composition of zooplankton was highest during summer, moderate in winter and autumn and least in monsoon season. Zooplankton are also considered as a good bio-indicator to assess the pollution status of a stream. Presence of indicator species like Brachionus calyciflorus, Brachionus falcatus and Mesocyclops leuckarti reveals that the stream gets organically polluted and rapidly moving toward a eutrophic condition. Therefore, frequent monitoring and proper treatment should be applied for conservation of the stream and its ecosystem.

Diversity and Seasonal Variations of Zooplankton in Dudhiya Talab of Sirohi, India

In this study, the seasonal fluctuations of zooplankton and specific physico-chemical parameters were examined in Dudhiya Talab, a significant artificial reservoir located in Sirohi, Rajasthan. During the research period, a total of 41 zooplankton species were identified, comprising 12 species of Rotifera, 14 species of Cladocera, 5 species of Ostracoda, and 4 species of Copepoda. Among these, Rotifera emerged as the predominant group, with a peak abundance of 689 individuals per liter recorded in the summer, while the lowest numbers were noted during the winter season. Additionally, the zooplankton community exhibited correlations with various physico-chemical parameters. The findings of this research suggest that the distribution and density of zooplankton species are significantly affected by the prevailing physical and chemical conditions of the aquatic environment. Key words: Zooplankton, Physico-chemical factors,P Cladocera, Rotifera.

Latitudinal variation in zooplankton over the Emperor Seamounts (34°–44° N, 170°–171° E) during the summer of 2019

The horizontal and vertical distributions of zooplankton over the Emperor Seamounts (Koko, Jingu, Nintoku, and Suiko guyots) were analyzed. The zooplankton was represented by four genera of amphipods, seven genera of pteropods, 39 genera of copepods, and larvae of benthic invertebrates and fish. The abundance and biomass of zooplankton increased towards higher latitudes along the series Koko < Jingu < Nintoku < Suiko guyots. The highest index of diversity was recorded over the Koko and Jingu guyots; the highest species richness occurred over the Jingu and Nintoku guyots. Small-sized copepods, appendicularians, chaetognaths, euphausiids, and fish eggs and larvae concentrated in the epipelagic; large copepods and ostracods were concentrated in the mesopelagic. We identified three types of zooplankton assemblages: a Subtropical assemblage between 34°–35°N characterized by tropical/subtropical forms; a Transition assemblage characterized by subtropical, subarctic, and widespread species between 38°–41°N; and a Subarctic assemblage characterized by subarctic and widespread species between 43°–44°N. The spatial distribution of zooplankton was a function of environmental variables such as surface salinity, temperature at 200 m, and, to a certain extent, by surface Chl-a concentrations.

Insights into the plankton community seasonal variations in a finer scale of the Bohai Sea: biodiversity, trophic linkage, and biotic-abiotic interplay

Plankton play an indispensable role in the biogeochemical processes of marine ecosystem. However, unraveling the intricate interactions among biodiversity, trophic linkages, and biotic-abiotic interplay between phytoplankton-zooplankton remains a significant challenge. Here, we conducted field studies in the neritic area of the Bohai Sea during autumn 2023 and spring 2024 to explore seasonal variations of both phytoplankton and zooplankton through microscope. Our analysis revealed a sharp decline in trophic interactions across phytoplankton and zooplankton, with an abundance ratio in autumn 2023 being 5.5 times higher than in spring 2024. Additionally, dominant plankton species (Y ≥ 0.02) exhibited obvious differences between the two seasons, with higher species diversity observed in autumn. Moreover, each dominant zooplankton species had distinct preferred food items in both seasons, with Rhizosolenia setigera being favored by Noctiluca scintillans and Acartia pacifica. Furthermore, a multivariate biota-environment analysis indicated that each dominant plankton species had unique correlation with specific environmental parameters, highlighting how plankton can fully exploit external environmental conditions to survive in seasonal variations. Ultimately, our findings emphasize significant seasonal dynamics and provide a solid foundation for assessing the potential impacts of environmental changes on plankton in coastal marine realm.

Ambivalent effects of mass cultivation of biodiesel producible green alga Tetraselmis striata on a microbial ecosystem: Evidence from mesocosm experiments

A 280-ton plant for the mass cultivation of Tetraselmis striata was operated from 2012 to 2019 to produce biodiesel fuel in western Korean coastal waters (Incheon) as a pilot project. This was the first instance globally where a microalgal mass cultivation plant for biodiesel production was implemented in coastal waters, and no prior studies had investigated the impact of microalgal mass cultivation plant on surrounding microecosystems. In this study, bioreactors (1× and 10×) mimicking a large-scale T. striata cultivation plant were installed in semi-permeable a mesocosms (5 tons) to assess their impact on the microbial ecosystem. The results showed that the release of large amounts of dissolve organic carbon (DOC) from the T. striata bioreactors. The 10× pond had a DOC concentration of 21.3 mg/L compared to the control pond of 2.1 mg/L. For the Water Quality Index (WQI), the 1× and 10× bioreactor installed mesocosms improved from Class II (Good) at the beginning of the experiment to Class I (Excellent) via decreasing nutrient levels and increasing of DO levels. However, from a biodiversity perspective, the microbial ecosystem deteriorated, with reductions in the diversity of zooplankton, ciliates, and phytoplankton. The correlation analysis and random forest variable importance measures indicated that the primary factor driving these changes was the alteration of the bacterial community due to elevated DOC levels. These findings indicate that while the mass cultivation of T. striata may improve physicochemical water quality, it has adverse effects on biological environments. Therefore, it is crucial to monitor physical, chemical, and biological factors comprehensively when cultivating microalgae on a large scale in marine environments.

Evaluating the quantitative performance of environmental DNA metabarcoding for freshwater zooplankton community: a case study in Lake Biwa, Japan.

Zooplankton monitoring is important for understanding their population dynamics and life history, ecosystem health, and environmental changes. Compared with traditional morphological identification, environmental DNA (eDNA) analysis allows for more sensitive and efficient monitoring of zooplankton diversity. Previous eDNA studies have primarily used metabarcoding approaches to reveal their richness and composition, whereas its performance in predicting zooplankton abundance remains understudied. We conducted water and bulk sampling in Lake Biwa, Japan, showing that the number of sequence reads by metabarcoding moderately correlated with eDNA concentrations estimated by quantitative real-time PCR (qPCR). In addition, the eDNA read number was significantly related to cladoceran and copepod abundance estimated by microscopy sorting, although there remained too much uncertainty in the read-abundance relationship. Moreover, there was a significant difference in species composition between eDNA metabarcoding and sorting. Although our results indicated the potential applicability of eDNA metabarcoding for quantifying multiple zooplankton abundance, several methodological validations in eDNA metabarcoding would also be required to optimize its performance in the future.

Spatial and seasonal variation in zooplankton dynamics in Parangipettai coastal waters Southeast coast of India

The distribution and composition of zooplankton are influenced by a combination of physico-chemical and biological processes, which in turn have effects on the entire ecosystem. In this study, the influence of environmental factors on zooplankton diversity in mangrove-estuarine coastal waters of Parangipettai, southeast coast of India, was investigated. Water samples were collected for a period of four years from January 2014 to December 2017. Totally, 145 species of zooplankton were recorded with highest belonging to the Arthropoda (63.21%) followed by Protozoa (10.53%), Cnidaria (7.95%), Urochordata (6.03%), Chordata (2.92%), Chaetognatha (2.62%), Mollusca (2.42%), Echinodermata (1.14%), Annelida (1.05%), Brachiopoda (1.01%), Ctenophora (0.57%) and Phoronida (0.55%). The findings of cluster, MDS, Factor analysis and CCA showed that variations in nutrient concentration may significantly alter the biotic community of zooplankton species. Furthermore, site score confirmed the effect of environmental conditions on zooplankton distribution. The result of TRIX showed the dry seasons are classified as scarcely eutrophied whereas wet seasons as moderately eutrophied. The findings of this study offer enhanced insight into how physico-chemical factors interact and vary over space and time, which is crucial for evaluating the effects of climate change on ecosystem services mediated by zooplankton.

Zooplankton vertical stratification in the East-pacific and Indian sectors of the Southern Ocean

IntroductionIn the Southern Ocean, the large-scale distribution of zooplankton, including their abundance and community composition from the epipelagic to the upper bathypelagic layers, remains poorly understood. This gap in knowledge limits our comprehension of their ecological and biogeochemical roles.MethodsTo better understand their community structure, depth-stratified zooplankton samples were collected from 0 to 1500 m during four summers in the East-Pacific and Indian sectors of the Southern Ocean. In addition, analysis of environmental drivers including temperature, salinity, dissolved oxygen, and chlorophyll a concentration, as well as water masses was conducted.ResultsOur study indicates that zooplankton diversity may be similar between the two sectors, while zooplankton abundance was higher in the East-Pacific sector during different sampling months and years. Moreover, zooplankton abundance decreased with depth in both sectors. Based on cluster analysis, zooplankton communities were generally divided by either the epipelagic or the deeper layers’ communities. In both sectors, the epipelagic layer was dominated by cyclopoid copepods, such as Oithona similis and Oncaea curvata, as well as calanoid copepods including Calanoides acutus, Rhincalanus gigas, and Ctenocalanus citer, while copepods and other taxa including Chaetognatha, Amphipoda, and Ostracoda, were important contributors to the deep layer communities.DiscussionOur analysis revealed that water masses, combined with their physical characteristics such as specific temperature and salinity ranges and depth, along with biological factors such as chlorophyll a concentration, might be the most important drivers for structuring zooplankton communities from epipelagic to upper bathypelagic layer.

Do red tide events promote an increase in zooplankton biodiversity?

Red tides occurring off the southern coast of Korea impact the marine ecosystem and aquaculture industries. Zooplankton are crucial in the food web, connecting primary producers to higher predators and interact diversely with red tide organisms. This study explores dynamics of the zooplankton community over seven years including three red tide and four non-red tide years in Tongyeong using metabarcoding. In non-red tide years, zooplankton diversity showed typical seasonal patterns, increasing from June to early October. However, during red tide years, diversity remained high, with a shift in species composition-decreased Copepoda and increased Branchiopoda, Echinodermata, Malacostraca, and Annelida. Diversity indices were significantly higher in red tide years across all periods except for the richness in “after” that showed an insignificant higher value. The differences in zooplankton assemblages across periods were influenced by surface temperatures and the density of the red tide-causing alga Margalefidinium polykrikoides. Eight species emerged as indicator species and showed direct correlations with M. polykrikoides and among them, seven species were indicator species for red tide occurrence years. The ecological characteristics of M. polykrikoides blooms and their recurrent occurrences over several decades suggest that zooplankton may adapt to the toxins and use these blooms as spawning cues. Overall, this study provides comprehensive understanding on changes in zooplankton communities during red tide events, offering novel insights into their ecology.