Chilika Lake Research Articles

A Novel Approach for Ex Situ Water Quality Monitoring Using the Google Earth Engine and Spectral Indices in Chilika Lake, Odisha, India

Chilika Lake, a RAMSAR site, is an environmentally and ecologically pivotal coastal lagoon in India facing significant emerging environmental challenges due to anthropogenic activities and natural processes. Traditional in situ water quality monitoring methods are often labor intensive and time consuming. This study presents a novel approach for ex situ water quality monitoring in Chilika Lake, located on the east coast of India, utilizing Google Earth Engine (GEE) and spectral indices, such as the Normalized Difference Turbidity Index (NDTI), Normalized Difference Chlorophyll Index (NDCI), and total suspended solids (TSS). The methodology involves the integration of multi-temporal satellite imagery and advanced spectral indices to assess key water quality parameters, such as turbidity, chlorophyll-a concentration, and suspended sediments. The NDTI value in Chilika Lake increased from 2019 to 2021, and the Automatic Water Extraction Index (AWEI) method estimated the TSS concentration. The results demonstrate the effectiveness of this approach in providing accurate and comprehensive water quality assessments, which are crucial for the sustainable management of Chilika Lake. Maps and visualization are presented using GIS software. This study can effectively detect floating algal blooms, identify pollution sources, and determine environmental changes over time. Developing intuitive dashboards and visualization tools can help stakeholders engage with data-driven insights, increase community participation in conservation, and identify pollution sources.

A study on influence of sediment properties on zooplankton abundance in Chilika Lake, Odisha, India

A study on influence of sediment properties on zooplankton abundance in Chilika Lake, Odisha, India

Taxonomic studies on a collection of Chalcididae (Hymenoptera, Chalcidoidea) from Chilika Lake, Odisha, India

The species diversity of family Chalcididae (Hymenoptera) from the islands of Chilika Lake, Odisha, India was studied. Eighteen species under seven genera of Chalcididae were identified with the addition of new distributional records for eight species from Odisha. Distributional data from India and the host details of all the listed species from Chilika Islands were provided.

Heavy Metals in the Sediments of the Chilika Lake, India: Contamination, Source and Toxicity Analysis

Heavy Metals in the Sediments of the Chilika Lake, India: Contamination, Source and Toxicity Analysis

A Check List of Algae from Chilika Lake, Orissa

A total of one hundred and two species of algae belonging to five divisions e.g. Cyanophyta, Chlorophyta, Bacillariophyta, Dinophyta and Rhodophyta were recorded from the Chilika lake during 2000-2001 of which fifty eight species belonging to four divisions were reported for the first time. Enteromorpha usneoides recorded in the Southern sector of the lake for the first time shows new and extended distribution range of Entromorpha species in India. A checklist of algal species found in Chilika lake has been given.

On a small collection of amphipods (Crustacea, Amphipoda) from Chilika Lake with the description of three new species and a new genus

The current study was conducted on the basis of a small collection of amphipods made from Chilika Lake that contained 4 species. Three were described as new species, including one new genus: Parhyale kalinga sp. nov., Chilikorchesta chiltoni gen. nov. sp. nov. and Grandidierella rabindranathi sp. nov., while a fourth one was a previously reported species: Quadrivisio bengalensis Stebbing, 1907. Parhyale kalinga sp. nov. can be differentiated from its closely related congeners Parhyale basrensis Salman, 1986 and Parhyale darvishi Momtazi & Maghsoudlou, 2016 by having male gnathopod 2 propoduswith 2 robust setae at the base of the palm and 2 small setae slightly behind the palm and dactylus much smaller than palm. Chilikorchestia chiltoni gen. nov. sp. nov. can be differentiated from the closely related genus Morinoia Lowry & Myers, 2019 by its incrassate male antenna 2 and untapered telson. Grandidierella rabindranathi sp. nov. can be differentiated from its closely related congeners G. mahafalensis Coutière, 1904 and Grandidierella nioensis Myers, Sreepada & Sanaye, 2019 by having male gnathopod 2 carpus oval shaped with both margins convex.

Artificial Neural Networks for Mapping Coastal Lagoon of Chilika Lake, India, Using Earth Observation Data

This study presents the environmental mapping of the Chilika Lake coastal lagoon, India, using satellite images Landsat 8-9 OLI/TIRS processed using machine learning (ML) methods. The largest brackish water coastal lagoon in Asia, Chilika Lake, is a wetland of international importance included in the Ramsar site due to its rich biodiversity, productivity, and precious habitat for migrating birds and rare species. The vulnerable ecosystems of the Chilika Lagoon are subject to climate effects (monsoon effects) and anthropogenic activities (overexploitation through fishing and pollution by microplastics). Such environmental pressure results in the eutrophication of the lake, coastal erosion, fluctuations in size, and changes in land cover types in the surrounding landscapes. The habitat monitoring of the coastal lagoons is complex and difficult to implement with conventional Geographic Information System (GIS) methods. In particular, landscape variability, patch fragmentation, and landscape dynamics play a crucial role in environmental dynamics along the eastern coasts of the Bay of Bengal, which is strongly affected by the Indian monsoon system, which controls the precipitation pattern and ecosystem structure. To improve methods of environmental monitoring of coastal areas, this study employs the methods of ML and Artificial Neural Networks (ANNs), which present a powerful tool for computer vision, image classification, and analysis of Earth Observation (EO) data. Multispectral satellite data were processed by several ML image classification methods, including Random Forest (RF), Support Vector Machine (SVM), and the ANN-based MultiLayer Perceptron (MLP) Classifier. The results are compared and discussed. The ANN-based approach outperformed the other methods in terms of accuracy and precision of mapping. Ten land cover classes around the Chilika coastal lagoon were identified via spatio-temporal variations in land cover types from 2019 until 2024. This study provides ML-based maps implemented using Geographic Resources Analysis Support System (GRASS) GIS image analysis software and aims to support ML-based mapping approach of environmental processes over the Chilika Lake coastal lagoon, India.

The taxonomy of Heteropanope indica De Man, 1887 from the Indian Ocean, with a note on Pilumnopeus pearsei (Rathbun, 1932) (Crustacea: Decapoda: Brachyura: Pilumnidae)

Benthopanope indica (De Man, 1887) was originally described from the Mergui Archipelago and has subsequently been reported from many Indo-West Pacific localities. The identity of this species is herein clarified. The re-examination of the type female, fresh specimens collected from Chilika Lake, Odisha State, India, as well as material from other locations, revealed that B. indica is not a Benthopanope species but should be assigned to Pilumnopeus instead. Pilumnopeus indicus comb. nov. is now restricted to the Indian Ocean and is reported from the western coast of Peninsular Malaysia for the first time. Heteropanope pearsei Rathbun, 1932, described from East Asia, previously synonymised under P. indicus by Sakai (1965), is here shown to be valid species of Pilumnopeus, and all previous records of “B. indica” from Japan, China, Taiwan, and Korea must be referred to this species. The two species can be differentiated by characters of the carapace, epistome, chelipeds and gonopods. Lectotypes are also designated for both species.

Cyanobacterial Genomes from a Brackish Coastal Lagoon Reveal Potential for Novel Biogeochemical Functions and Their Evolution.

Cyanobacteria are recognised for their pivotal roles in aquatic ecosystems, serving as primary producers and major agents in diazotrophic processes. Currently, the primary focus of cyanobacterial research lies in gaining a more detailed understanding of these well-established ecosystem functions. However, their involvement and impact on other crucial biogeochemical cycles remain understudied. This knowledge gap is partially attributed to the challenges associated with culturing cyanobacteria in controlled laboratory conditions and the limited understanding of their specific growth requirements. This can be circumvented partially by the culture-independent methods which can shed light on the genomic potential of cyanobacterial species and answer more profound questions about the evolution of other key biogeochemical functions. In this study, we assembled 83 cyanobacterial genomes from metagenomic data generated from environmental DNA extracted from a brackish water lagoon (Chilika Lake, India). We taxonomically classified these metagenome-assembled genomes (MAGs) and found that about 92.77% of them are novel genomes at the species level. We then annotated these cyanobacterial MAGs for all the encoded functions using KEGG Orthology. Interestingly, we found two previously unreported functions in Cyanobacteria, namely, DNRA (Dissimilatory Nitrate Reduction to Ammonium) and DMSP (Dimethylsulfoniopropionate) synthesis in multiple MAGs using nirBD and dsyB genes as markers. We validated their presence in several publicly available cyanobacterial isolate genomes. Further, we identified incongruities between the evolutionary patterns of species and the marker genes and elucidated the underlying reasons for these discrepancies. This study expands our overall comprehension of the contribution of cyanobacteria to the biogeochemical cycling in coastal brackish ecosystems.

Sediment-associated microplastics in Chilika lake, India: Highlighting their prevalence, polymer types, possible sources, and ecological risks

The primary objective of this research was to assess microplastics (MPs) in the sediments of Chilika lake. MPs were extracted from 22 sediment samples using the density separation method combined with vacuum pump filtration. A stereo-zoom microscope and Raman spectroscopy were employed to identify the sediment-associated MPs. The total MPs collected from all 22 sites was 440 ± 3.53 particles kg−1 wet sediments, with sizes ranging between 50 and 500 μm. In terms of morphology, fibers and fragments emerged as the dominant MP types, with counts of 210 ± 1.66 and 175 ± 1.76 particles kg−1 wet sediments, respectively. Raman spectroscopy verified the presence of various MP polymers in the sediments, predominantly HDPE (37 %), followed by PS (20 %), PET (18 %), PA (11 %), PP (7 %), and PC (7 %). A notable color variation was observed in MPs; black being the most prevalent (38.8 %), succeeded by blue (19.5 %), green (11.8 %), white (11.5 %), red (10.6 %), and transparent (7.5 %). ANOVA results indicated significant (p > 0.05) variations in MP abundance across the 22 sampling locations. However, principal component analysis (PCA) and multiple regression analysis indicated that water quality parameters did not significantly influence MP abundance, yet it was found that MP retention was higher in fine-grained sediments like clay and silt. The leading sources of MPs in Chilika lake were found to be aquafarming, trailed by river and sewage discharges, fishing activities, antifouling coatings and tourism. Additionally, the pollution load index (PLI) was employed to gauge the ecological risks, categorizing the lake under risk category 1, which implies a minimal level of MPs pollution. This research aims to serve as an early warning system for MPs pollution in productive brackish water habitats globally, including Chilika lake, guiding policymakers towards appropriate management strategies and preventive measures.

Assessment of Antimicrobial and Antioxidant Potential of Oscillatoria sancta and Oscillatoria proteus Isolated from Chilika Lake.

Filamentous cyanobacteria are a promising source of biologically active secondary metabolites with antioxidant, antimicrobial, antiviral and anticancer properties. Previously, cyanobacteria isolated from fresh and marine water were studied extensively, but those isolated from brackish water were less investigated. The purpose of this study was to examine the antimicrobial activities as well as the potential antioxidant capacity of two cyanobacterial strains (Oscillatoria proteus and Oscillatoria sancta) obtained from Chilika Lake. The pigment and antioxidant was assayed using a spectrophotometer; antimicrobial activity was studied by minimum inhibitory concentration (MIC); and the presence of phytoconstituents was detected using gas chromatography mass spectrometry (GC-MS). The solvents used for extraction were methanol, acetone and benzene. The experimental data indicates that the total phenolic and flavonoid content was highest in O. sancta (58.26 ± 0.72µg/g, 38.45 ± 0.79µg/g, respectively). Similarly, the methanol extract of O. sancta presented the maximum antioxidant potential in both DPPH (83.18 ± 0.57%) and ABTS (68.42 ± 1.40%) radicals. Besides, more reducing power was also recorded in methanol extract of O. sancta as compared to O. proteus. Further, higher enzymatic activity (superoxide dismutase and catalase) was observed in O. sancta. The antimicrobial potential against bacterial and fungal pathogens demonstrated better activity in O. sancta. In GC-MS analysis seven major chemical classes have been detected. Differential results was found in the two species of Oscillatoria; however, both have potential antimicrobial and antioxidant properties. The findings have pharmaceutical and nutraceutical importance.

Partial purification and characterization of an extracellular Chitin Deacetylase from Streptomyces griseoinacarnatus RB7AG isolated from Chilika lake

An extracellular thermo-alkali tolerant chitin deacetylase (CDA) was obtained from Streptomyces griseoincarnatus RB7AG, isolated from Chilika lake sediments. The purification of the enzyme was carried out by ammonium sulfate precipitation, followed by chromatographic separation by diethylaminoethanol sepharose (DEAE sepharose) ion exchange resin. This purification resulted in a 29.42-fold increase in purity, achieving a specific activity of 3.09 U/mg with a yield of 40%. The molecular weight of the enzyme was 50 kDa. The enzyme exhibited optimal activity at a temperature of 40 °C and a pH of 8.0, displaying remarkable stability over a wide range of temperatures (4–25 °C) and pH levels (6.0–9.0). It demonstrated enhanced enzymatic activity when exposed to certain metal ions, particularly Cu2+, Mg2+, and Fe3+. The enzyme exhibited Km and Vmax values of 1.55 mg/mL and 20.9 µmol/min. This CDA exhibited activity towards glycol chitin and chitin oligomers with a degree of deacetylation greater than 75%. MALDI-TOF/MS (Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry) data revealed that the isolated protein was found to be close relatives of the polysaccharide deacetylase family and have four conserved CE4 (Carbohydrate esterase 4) family. Based on the SDS PAGE (Sodium dodecyl-sulfate polyacrylamide gel electrophoresis), activity assays, generation of a higher degree of deacetylated product, and MALDI-TOF/MS data, it is proposed that the purified enzyme from Streptomyces griseoincarnatus RB7AG is an extracellular chitin deacetylase.

Sustainable Harvests under Different Bio-economic Scenarios of Chilika Wetland’s Fisheries

The primary goal of fisheries management is to control overfishing and unregulated fisheries to protect stocks and boost the value of fish resources. In this study, we compare harvesting and fishing efforts in the maximum economic yield (MEY), maximum sustainable yield (MSY), and open access (OA) scenarios using Gordon-Schafer’s bioeconomic model to examine the economic status of Chilika’s fisheries. This paper also measures the effectiveness of Chilika Lake’s restoration measures. An independent sample t-test with bootstrap confidence intervals indicates the results’ robustness and concludes that the fisheries’ output has increased in the post-restoration period (2003–04 to 2020–21) in a statistically significant way. The estimated measures serve as the focal points for designing sustainable and optimal fisheries management strategies. They add to the ongoing research on stock evaluation, which helps determine harvesting effectiveness and strengthens the fishing stock to avoid exhaustion. Therefore, the expectation is that the outputs in the forms of optimal extraction and an enhanced management tool will improve livelihood opportunities and enhance other socioeconomic components of the fisheries sector. As a result, the findings will aid policymakers and other interested parties in creating a suitable harvesting strategy to attain economic optimality.

Comparative therapeutic efficacy of oral administration of gluconeogenic precursors with nicotinamide and intravenous hypertonic dextrose solution for management of subclinical ketosis in Chilika buffaloes.

Ketosis in dairy animals originates from negative energy status, associated increased absorption, and production of ketone bodies exceeding their use by the ruminants as an energy source. The present therapeutic experiment was carried out in 29 herds of Chilika buffaloes in 16 villages of three adjoining districts of Chilika Lake, Puri, Khurda, and Ganjam. Twenty Chilika buffaloes, detected positive for subclinical ketosis, were randomly selected for the study and divided into 2 groups, groups II and III, and were treated with hypertonic dextrose solution intravenously or gluconeogenic precursors along with nicotinamide orally, along with other supportive drugs in both the groups. Ten lactating Chilika buffaloes with no signs of ketosis and detected negative on Rothera test were included in the study as healthy controls (group I). Blood and milk samples were collected from all the 30 recruited buffaloes on days 0 (pre-treatment), 7, 14, and 28 for haematological and biochemical analysis. The subclinical ketosis in Chilika buffaloes did not have overt clinical signs. However, close examination revealed gradual drop in milk yield (100%), inappetence (59%), debility (46%), and uncoordinated gait (10%) without excitatory nervous signs. On day 7 following treatment, blood glucose concentration increased significantly. The mean serum triglyceride concentration of group III, treated with gluconeogenic precursors with nicotinamide, continued to decline significantly on subsequent observations. The serum enzyme activity, indicating status of liver function, declined following treatment in both the therapeutic groups. The intravenous administration of hypertonic dextrose solution compared to use of oral gluconeogenic precursors along with nicotinamide efficiently restored recovery from the subclinical ketosis in Chilika buffaloes.

Microplastics in Indian Brackish Water Lagoon: Occurrence and Distribution in the Chilika Lake

Microplastics in Indian Brackish Water Lagoon: Occurrence and Distribution in the Chilika Lake

Perceptions towards ecotourism practice and the willingness to pay: Evidence from Chilika coastal wetland ecosystem, Odisha

Empirical studies show that biodiversity conservation, ecotourism development, livelihoods of local people and ethnicity in protected areas significantly impact society's well-being. However, achieving the aforementioned goals is extremely difficult without strong support, commitment from host communities, and effective coordination among ecotourism stakeholders. This study sought to explore the perceptions of various stakeholders regarding the impacts and importance of ecotourism and their willingness to pay for ecotourism development and biodiversity conservation at Chilika Lake, Odisha. We conducted semi-structured interview of 250 respondents in different areas adjacent to Chilika Lake such as Balugaon, Barakul, Pathara and Khalikot. To grasp the above objectives, we used the contingent valuation method (CVM) and the Double Hurdle Model to identify the determinants of willingness to accept (WTA) and willingness to pay (WTP). Simple descriptive statistics were used to analyse the perception of ecotourism impacts. The study found that local people in the study region perceived both positive and negative impacts of ecotourism. There was sufficient evidence of conflicts of interest in resource use, limited community involvement in ecotourism planning and decision-making, and low economic benefits. However, the study also found that instead of a range of negative impacts, a variety of stakeholders expressed a willingness to develop ecotourism with the prospect of improving their various needs. The results of the empirical double hurdle model showed that the variables of education, total income, importance of the lake, level of awareness, and occupation significantly impacted the willingness to accept the offered payment. On the other hand, age, marital status, education, total income, importance of the lake, and level of awareness have a significant influence on the willingness of different stakeholders to pay the offered amount. A detailed understanding of ecotourism, consideration of socioeconomic and demographic characteristics, and the development of ecotourism products and services enables various stakeholders to adjust their behaviour towards sustainability, and can contribute to an effective information and planning process which may lead to greater promotion of ecotourism.

Genome analysis of biosurfactant producing bacterium, Bacillus tequilensis.

Bioremediation is crucial for recuperating polluted water and soil. By expanding the surface area of substrates, biosurfactants play a vital role in bioremediation. Biosurfactant-producing microbes release certain biosurfactant compounds, which are promoted for oil spill remediation. In the present investigation, a biosurfactant-producing bacterium Bacillus tequilensis was isolated from Chilika Lake, Odisha, India (latitude and longitude: 19.8450 N 85.4788 E). Whole-Genome Sequencing (WGS) of Bacillus tequilensis was carried out using Illumina NextSeq 500. The size of the whole genome of Bacillus tequilensis was 4.47 MB consisting of 4,478,749 base pairs forming a circular chromosome with 528 scaffolds, 4492 protein-encoding genes (ORFs), 81 tRNA genes, and 114 ribosomal RNA transcription units. The total raw reads were 4209415, and the processed reads were 4058238 with 4492 genes. The whole genome obtained from the present investigation was used for genome annotation, variant calling, variant annotation, and comparative genome analysis with other existing Bacillus species. In this study, a pathway was constructed which describes the biosurfactant metabolism of Bacillus tequilensis. The study identified that genes such as SrfAD, SrfAC, SrfAA and SrfAB are involved in biosurfactant synthesis. The sequence of the genes SrfAD, SrfAC, SrfAA, SrfAB was deposited in GenBank database with accession MUG02427.1, MUG02428.1, MUG02429.1, MUG03515.1 respectively. The whole genome sequence was submitted to GenBank with an accession RMVO00000000 and the raw fastq reads were submitted to SRA, NCBI repository with an accession: SRX5023292.

Contextualizing the lake ecosystem syndromes and research development activities in Chilika Lake (Odisha coast, India): a bibliometric overview (1970–2021)

Contextualizing the lake ecosystem syndromes and research development activities in Chilika Lake (Odisha coast, India): a bibliometric overview (1970–2021)

Estimation of Soil Erosion Using RUSLE Model and GIS Tools: A Study of Chilika Lake, Odisha

Abstract Chilika Lake is the largest coastal lagoon on the eastern coast of India. The aerial extension of the lake fluctuates between 1165 km2 to 906 km2. The opening of new inlet into the lake has enriched its biodiversity but also has increased the rate of siltation, which inturn affected the lake’s water holding capacity, causing ecological repercussions and impacting its flora and fauna. The RUSLE model integrated with remote sensing and GIS techniques was used to assess the soil loss in watershed of Chilika Lake. The model takes into account various factor viz. Crop /cover management factor (C), Soil erodibility factor (K), slope length (L), Conservation support practice factor (P), Rainfall erosivity factor (R), and steepness factor (S) to estimate potential soil loss. The results of the study reveal that 486.92 km2 i.e., 73.16% area of the Chilika watershed falls under least risk category of soil erosion, 44.17 km2 (6.6%) under moderate category, while, about 11% is at high, 8.8% at very high, and 0.043 at severe risk of soil erosion. The analysis estimates the annual average soil loss rate in the catchment of Chilika Lake to be 32.41 ton/ha/yr. The raster layers developed to study spatial soil loss indicate that the catchment of the lake is under the grip of soil erosion and siltation problems. Therefore, the study recommends immediate action of conservation and management planning processes to save the lake from further degradation.

Development of chlorophyll-a concentration estimation algorithm for turbid productive inland waters in India

Estimation of Chlorophyll-a (Chl-a) concentration from remote-sensing reflectance derived from satellite imagery is highly effective in monitoring the spatial and temporal optical variations in water bodies. In turbid, productive and inland waters, implementation of traditional Chl-a estimation algorithms using the blue and green wavelength bands results in higher error in estimated Chl-a. To minimize the absorption and scattering effects of other water constituents like colored dissolved organic matter and particulate matter, the wavelengths bands in red and Near Infrared (NIR) are generally used for estimating Chl-a concentration in productive waters. Owing to a widely observed optical variability in natural waters, a single universal algorithm is not applicable to all waterbodies, hence, regional tuning of algorithms is necessary for estimating Chl-a in turbid and inland productive waters. Here, a 2-band based algorithm of the form and a 3-band algorithm of form were tuned for Chl-a estimation based on field measurements carried out in three water bodies, Chilika Lake of Orissa, Ujjani Reservoir of Maharashtra, Vallabh Sagar Reservoir of Gujarat, India, wherein the observed Chl-a concentration range is 5–33 mg/m3. Together with measured in situ reflectance spectra and concurrent Chl-a concentrations, tuning of red-NIR algorithms is performed. The optimal wavelengths to estimate Chl-a found by the proximal sensing method are = 691 nm and = 667 nm in case of 2-band red-NIR type algorithm. For 3-band red-NIR algorithm, the optimal wavelengths are = 670 nm, = 696 nm and = 740 nm. The mean absolute percentage error (MAPE) and root-mean-square error (RMSE) values obtained for the estimated Chl-a using the tuned 2-band red-NIR algorithm are 29.9% and 5.35 respectively. Similarly, RMSE and MAPE values for Chl-a concentration estimated using the 3-band tuned red-NIR algorithm are 4.24 and 22.5%, respectively. The tuned 2-band and 3-band algorithms resulted in better Chl-a estimates than the fourteen blue-green and red-NIR algorithms from previous studies. The 2-band and 3-band algorithms were re-calibrated to wavelengths present in the ocean land color imager (OLCI) sensor on Sentinel-3 satellite to monitor these water bodies. Spatio-temporal analysis of OLCI imagery derived Chl-a concentrations over Chilika lake (2019 and 2020) indicated seasonal variations. The tuned 3-band red-NIR algorithm exhibited robust performance in all seasons despite wide variations in colored dissolved organic matter and suspended sediments. The tuned red-NIR algorithms are useful in monitoring inland turbid productive waters with upcoming missions such as Plankton, Aerosol, Cloud Ecosystem (PACE) and Oceansat-3.