Environmental Characterization of Two Ecologically Distinct Gangetic Oxbow Lakes Using Zooplankton Taxonomic Indices In Ecological Monitoring: A Comparative Approach (original) (raw)
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2022
The present investigation attempted environmental characterization of two ecologically distinct oxbow lakes through zooplankton taxonomic indices using a comparative approach. These closed and seasonally open oxbow lakes are subjected to eutrophication due to different nutrient concentration and eco-hydrological characteristics. The zooplanktons are closely link with surrounding environment throughout their life cycles and change rapidly, hence act as potential indicator of eutrophication. The study examined the assemblage pattern of zooplankton community and trophic state of two ecologically distinct oxbow lakes based on eco-hydrological factors and community structure of rotifers and planktonic crustaceans seasonally over a period of 2 years. Comprehensive trophic state index (mTSI), rotifer trophic state index (mTSIROT) and Crustacean based indices (TSICR) were used to assess the degree of eutrophication. The Kruskal-Wallis test confirmed the heterogeneity of the eco-hydrological...
Caspian Journal of Environmental Sciences, 2021
Long-term (1998-2018) studies have been carried out on the small lake, Karasikha, located in the territory of the Volga-Kama State Nature Biosphere Reserve. Physicochemical characteristics of the lake water classify it as eutrophic, polluted, with a low oxygen content, but a high content of organic matter and phosphates. In parallel, some studies were carried out on its zooplankton community. Karasikha Lake is the habitat of 70 species of planktonic rotifers and crustaceans identified. Based on the number of species, rotifers predominated and their largest number belonged to Brachionidae family. On average 3-4 species were dominant, as indicators of eutrophic and polluted waters. However, with a relatively high species richness of zooplankton, the community has low quantitative indicators. The low oxygen content in the water column makes zooplankton concentrate mainly in the epilimnion layer (up to 2-3 m in depth). The lowest quantitative indicators of zooplankton are characteristic of the under-ice period, which is also associated with a lack of oxygen in the water. The community is dominated by indicators of dirty waters. The structure of zooplankton communities is typical of highly polluted lakes. Indices based on the taxonomic structure of zooplankton classify the reservoir as highly eutrophic and even hypertrophic.
Hydrobiologia
With the implementation of the EU Water Framework Directive (WFD), the member states have to classify the ecological status of surface waters following standardised procedures. It was a matter of some surprise to lake ecologists that zooplankton were not included as a biological quality element (BQE) despite their being considered to be an important and integrated component of the pelagic food web. To the best of our knowledge, the decision of omitting zooplankton is not wise, and it has resulted in the withdrawal of zooplankton from many so-far-solid monitoring programmes. Using examples from particularly Danish, Estonian, and the UK lakes, we show that zooplankton (sampled from the water and the sediment) have a strong indicator value, which cannot be covered by sampling fish and phytoplankton without a very comprehensive and costly effort. When selecting the right metrics, zooplankton are cost-efficient indicators of the trophic state and ecological quality of lakes. Moreover, they are important indicators of the success/failure of measures taken to bring the lakes to at least good ecological status. Therefore, we strongly recommend the EU to include zooplankton as a central BQE in the WFD assessments, and undertake similar regional calibration exercises to obtain relevant and robust metrics also for zooplankton as is being done at present in the cases of fish, phytoplankton, macrophytes and benthic invertebrates.
Biodiversitas Journal of Biological Diversity
Zooplankton is a potentially powerful tool for assessing the trophic state of aquatic ecosystems. The current paper studied taxonomic composition and biomass of zooplankton communities in ten lakes within Ilmen State Reserve, Chelyabinsk region, Russia and identified the influence of trophic status on its formation. Integrated samples were taken from epilimnion in the summer of 2016-2019. Several criteria were used to determine trophic status: the taxonomic structure and biomass of zooplankton; some hydroecological indicators some hydroecological indicators and the Carlson index. The trophic status of the studied lakes, determined based on the zooplankton biomass, revealed that most of the lakes were in the status of mesotrophic. The number of zooplankton species in the lakes was 44 with Pleuroxus laevis, Bosmina longirostris, Simocephalus vetulus were the most numerous species in mesotrophic lakes; while Chaetonotus ploenensis, Keratella quadrata frenzeli, Leptodora kindti are rare. Zooplankton communities of Bolshoye Miassovo and Maloye Miassovo Lakes were characterized by high species diversity and considered as one of the most significant among the foothill lakes of the eastern slope of South Ural. The study reveals that hydroecological assessment of the ecological status is not exactly precise, as values are not stable and can change not only under the anthropogenic influence but also due to many natural abiotic environmental factors. The research shows that species composition and biomass of zooplankton communities could provide a more accurate assessment of the trophic status of water-bodies.
Trophic state assessment based on zooplankton communities in Mediterranean lakes
Hydrobiologia
Eutrophication assessment is made widely using Carlson Trophic State indices (TSI) [e.g. secchi disc depth (TSI SD)] or phytoplankton biomass. Recently, two Carlson type indices using rotifers (TSI ROT) and crustaceans (TSI CR) were developed from Polish lakes. In the present study, both indices were applied to zooplankton communities from 16 Greek lakes, covering the entire trophic state spectrum, in order to test their application in a different climatic zone, the Mediterranean. The evaluation of the indices (TSI ROT and TSI CR) was made comparing the trophic state of each sampling/lake based on TSI SD and mean summer phytoplankton biomass. Both indices increased across the eutrophication gradient but misclassify the trophic state. We propose a new index, TSI ZOO , the average of the formulae TSI ROT and TSI CR which are significantly correlated with the eutrophication proxies. All three zooplanktonic indices can efficiently detect low (oligotrophic-mesotrophic) and high (eutrophic-hypertrophic) trophic state using the boundaries \ 45 for TSI ROT and TSI ZOO and\ 50 for TSI CR. All zooplanktonic indices are promising and effective tools for monitoring and assessment of eutrophication of Mediterranean lakes when mean values are used. Still, TSI ZOO should be preferred as the best index that correlated with eutrophication which had the best estimations. Keywords Carlson Trophic State indices Á TSI CR Á TSI ZOO Á TSI ROT Á Greek lakes Á Eutrophication
Aquatic Ecology, 2021
The European Water Framework Directive implements the policies to achieve a good ecological status of all European waterbodies. To determine the ecological potential in freshwater environments, abiotic (morphology, physical and chemical variables) and biotics (algae, fishes, etc.) metrics are used. Despite their importance in trophic web, zooplankton was not included as one of the Biological Quality Elements (BQE) to determine the water quality. In the present research, we studied the zooplankton species that can be considered as indicators of trophic status and ecological potential for more than 60 water reservoirs. The data were obtained from more of 300 samples collected during 10 years from reservoirs at Ebro River watershed, which is the largest basin in Spain. According to their physicochemical and biological elements, the trophic status and ecological potential of these reservoirs were established. More than 150 zooplankton species were identified during the study. The result...
Water
With the intensification of aquaculture technologies, the amount of feed input and waste material is increasing, creating potentially negative impacts on freshwater habitats receiving effluent from such systems. Changes in biodiversity of zooplankton communities is often used to assess the effects of such impacts. Rotifers are suitable for bioindication of water quality due to their fast reaction to environmental changes. We examined seasonal changes in the diversity of rotifer communities along a 3.5 km section of the biggest oxbow lake in the Tisza River basin, Hungary, that received inflow from an intensive tank-based aquaculture farm. We detected a species-rich rotifer community with 26 species. Using the Rényi one-parameter diversity index families, we found that biodiversity increased away from the point of inflow in spring, but after a summer transition period the situation became partially reversed during autumn. At the beginning of the study period, the nutrient-rich efflue...
Due to the intensive mixing polymictic lakes should be homogenous. However, morphometric diversity and high water dynamics contribute to the differentiation of many parameters in various areas of the lakes. This study analyzes both phytoplankton and zooplankton to assess differences in water quality along the north-south axis of the longest lake in Poland. New phytoplankton indicators were applied for determining the lake's ecological status: the Q index based on functional groups and the PMPL (Phytoplankton Metric for Polish Lakes) index based on phytoplankton biomass. TSI ROT index (Rotifer Trophic State Index), which comprises the percentage of species indicating a high trophic state in the indicatory group and the percentage of bacteriovorus in the Rotifera population, was used for zooplankton analysis.
A comparative study of four indexes based on zooplankton as trophic state indicators in reservoirs
Limnetica, 2019
A comparative study of four indices based on zooplankton as trophic state indicators in reservoirs This study aims to examine four recently conducted trophic state indices that are based on the density of zooplankton and designed for estimating the trophic state of inland waters. These indices include two with formulations based on quotients or ratios, the Rcla and the Rzoo-chla, which were proposed and validated in the European project ECOFRAME (Moss et al., 2003), and two with formulations based on the incorporation of a statistical tool comprising canonical correspondences analysis (CCA), the Wetland Zooplankton Index proposed in 2002 by researchers from McMaster University of Ontario (Lougheed & Chow-Fraser, 2002) and the Zooplankton Reservoir Trophic Index, an index recently designed by the Ebro Basin Authority and on which this manuscript is the first article. These indices were studied and applied in 53 heterogeneous reservoirs of the Ebro Basin. In addition, all were subsequently validated by Carlson's Trophic State Index based on the amount of chlorophyll a (Carlson, 1977), with significant differences found between them.