Pulicat Lake Research Articles

Carbon footprint and associated environmental impacts of fisheries on the Pulicat region, Southern India: A preliminary study

The current research analyzed carbon emissions resulting from fossil fuel consumption in the Pulicat region. This area is home to approximately 3500 motorized boats dedicated to fishing activities. Through this comprehensive study, we assessed the fuel consumption and subsequent carbon emissions within the motorized fishing sector. Our investigation revealed that traditional fishing methods in Pulicat Lake consumed 148,515 L of fuel whereas fishing methods along the Pulicat coast consumed a substantial 1650,429 L of fuel during the study period spanning from June 2022 to May 2023. In total, the Pulicat region accounted for the consumption of 1798,944 L (1547.1 metric tonnes (MT)) of fuel, contributing a mere 0.00004% to the global fuel consumption levels attributed to the small-scale fishing sector. Furthermore, the cumulative CO2 emissions resulting from fishing activities in the Pulicat region amounted to 4731.23 MT, representing a 0.001% of the overall CO2 emissions attributed to the Indian fishing sector. Remarkably, the Pulicat region emitted 1.05 MT of CO2 to capture 1 t of fish during the study period. The average CO2 emissions of fish stood at 1.08 MT of CO2/ ton of fish. Our analysis revealed that October 2022 recorded the highest carbon emissions per ton of fish at 1.45 MT of CO2 whereas May 2023 exhibited the lowest carbon emissions at 0.54 MT of CO2/ ton of fish. Within the Pulicat region, the use of crab lift net fishing methods in the lake (0.10 MT of CO2 per ton of fish) and purse seine techniques along the coast (0.65 MT of CO2/ ton of fish) emerged as the most energy-efficient fishing methods among the various alternatives. This study offers an in-depth exploration of carbon emissions originating from the Pulicat region’s fishing activities, providing valuable insights into the environmental impact of this crucial sector.

Diversity and distribution of foraminifera and tintinnids (bio‐indicators) from Pulicat Lake, India

AbstractThe foraminifera and tintinnids are essential indicators of the health status of marine and estuarine ecosystems, both past and present, and can be used for monitoring purposes in the future. Tintinnids are known to group among ciliates possessing hard loricate to be considered by hydrogeologists as one of the bio‐indicator species, exhibiting a strong positive correlation with phytoplankton. Pulicat Lake is a marginal marine environment present near the south coast of India. Intertidal sediment samples were collected from September 2013 to August 2014 and were subjected to isolate the foraminiferans and tintinnids by adopting standard methods. In all, twenty‐one genera and 24 species of foraminifera have been identified from the stream, where Quinquelina seminulum was found to be abundant. Contrary to this, a minimum number of species was present in the freshwater inflow zone, mainly Amomalinula glabrata, Haplophragmoides kirki, Natlandia secasensi and Valvulineria candeiana. Tintinnopsis are recorded in the sampling sites, belonging to 5 families and 6 genera, and 12 species have been identified, and among these Favella campanula species was found to be abundant in the study area. From our results, the recorded species in terms of numerical abundance of foraminiferans appeared predominant over the tintinnids. The dominant role of foraminiferans may be a significant contribution to the carbon cycle of marine/estuarine ecosystems proved elsewhere in turn responsible for the substantial uptake of phytodetritus deposition. Based on these findings, our preliminary study may be useful to explore the carbon sequestration process in the Pulicat Lake ecosystem.

Assessment of blue carbon in seagrass meadows in Pulicat Lake, Andhra Pradesh, India

Coastal ecosystems such as seagrass, mangroves and saltmarshes sequester and store large quantities of carbon in the soil. Carbon sequestration potential of four seagrass species Halophila ovalis, Halodule pinifolia, Syringodium isoetifolium and Halodule uninervis in Pulicat Lake, Andhra Pradesh, India was assessed. The mean seagrass biomass within the seagrass beds in the lake ranged from 1.43 ± 0.06 to 2.01 ± 0.12 Mg/ ha and the total blue carbon storage in the seagrass meadows ranged from 0.49 ± 0.15 to 9.52 ± 0.15 Mg C ha−1 while stored carbon in the sediment ranged from 1.29 ± 0.04 to 11.94 ± 0.15 Mg C ha−1. Regression analysis showed a considerable correlation between seagrass carbon and sediment carbon. Among the environmental parameters analyzed, pH showed significant correlation with seagrass biomass and sediment carbon (P < 0.05). The present study demonstrates the carbon sequestration potential of seagrass ecosystem in the Pulicat Lake.

Heavy Metals in Wetland Ecosystem: Investigating Metal Contamination in Waterbirds via Primary Feathers and Its Effect on Population and Diversity

Wetlands are dynamic ecosystems that provide feeding and nesting grounds for diverse species of waterbirds. The quality of wetland habitat may have an impact on the density, diversity, and species richness of waterbirds. Toxic metal contamination is one of the most significant threats to wetland habitats. Feathers are a key indicator of heavy metal contamination in avian communities as a non-invasive method. We examined the levels of Arsenic (As), Cadmium (Cd), Cobalt (Co), Chromium (Cr), Copper (Cu), Lead (Pb), Nickel (Ni), and Zinc (Zn) using ICP-AAS and standards of digestion procedure from the primary feathers of 10 distinct species of waterbirds. The study was conducted at four wetlands, viz., Point Calimere Wildlife Sanctuary (Ramsar site); Pallikaranai Marshland (Ramsar site); Perunthottam freshwater lake (unprotected wetland), Tamil Nadu and the Pulicat Lake, Andhra Pradesh, (Ramsar site), India. The Large crested tern had higher concentrations of As, Co, Cr, and Ni. Cu was greater in the Indian pond heron, and Zn was higher in the Grey heron. The accumulation of metals differed among the waterbirds (p &lt; 0.05), and the inter-correlation of metals found positive influences between the tested metals, i.e., Co was positively associated with As, Cr had a positive correlation with As and Co, and Ni was positively correlated with As, Co, Cr, and Cu. In contrast, Pb had a positive association with Cu and Ni. The Zn was associated with Co, Cr and Cu. The level of metals in waterbirds was Zn &gt; Cu &gt; Cr &gt; Ni &gt; Pb &gt; Co &gt; Cd &gt; As. The results showed that metal levels in the primary feathers of waterbirds were greater than the other species of waterbirds examined across the world. Thus, the study emphasizes that managing wetlands and controlling pollution is crucial to saving waterbirds; otherwise, the population and diversity of waterbirds will decline and become a significant threat to waterbird communities.

Faunal Diversity of Pulicat Lake, Southeast Coast of India

Pulicat Lagoon, located on the South-east Coast of India, indeed plays a crucial role in supporting a diverse range of aquatic and avian species. Pulicat Lagoon is known for its rich biodiversity. As mentioned, it supports a variety of species, including crustaceans, finfish, and migratory birds. These species are not only ecologically important but also contribute to the local economy through fisheries and tourism. The present study is an attempt to compile the faunal list based on the field survey conducted during 2005- 2007 &amp; May to Dec 2022 by Marine Biology Regional Centre, Zoological Survey of India, Chennai and from the published literature. Altogether 354 species belong to six phyla are reported so far. Among them 65 species of microfauna (phytoplankton, and zooplankton) and 289 species of macrofauna (Cnidaria, Arthropoda, Mollusca, Echinodermata, Pisces, and Birds) were reported so far. The lagoon is also important for the local fishing communities. It serves as a breeding ground for many fish species, which are essential for the livelihoods of the people living in the region. Sustainable fisheries management is vital to ensure the long-term well-being of these communities. Periodical research and monitoring of the lagoon's biodiversity and ecological health are crucial. This can help track changes, identify emerging threats, and guide conservation efforts. Pulicat Lagoon is a valuable ecosystem that supports a wide range of species and plays a vital role in the local economy. Conservation efforts should focus on maintaining the lagoon's ecological balance, preventing further degradation, and involving local communities in sustainable management practices to ensure its long-term survival. Pulicat Lagoon faces several environmental challenges, including silt deposition, habitat degradation, soil erosion, and changes in freshwater flow. These issues can disrupt the delicate balance of the ecosystem and threaten the survival of various species.

Molecular signatures and diagnostic nucleotides for the fishes of the tropical brackish water lake in South Asia for conservation and management

The Pulicat Lake habitat is one of the most productive and precious ecosystems in India. This study aimed to develop the species-specific molecular signatures and determine the phylogenetic relationship of fish species distributed in the Pulicat Lake. In the present study, a data set of 1008 mtCOI sequences was obtained from the published resources and used to screen character-based molecular diagnostic keys for species in silico. DNA barcodes were generated from 29 fish species fish representing 7 orders, 28 genera, and 21 families. Species-specific probes with a length range of 18–32 bp were designed on the basis of identified diagnostic nucleotide sites. The probes, developed in this study, could be used to develop DNA chips to identify fish species more quickly and accurately. The developed molecular signatures in this study will be helpful in the effective fishery management of these fish genetic resources.

Assessment of benthic habitats of highly threatened oyster reefs of Pulicat Lake, India

The present study was aimed at demarcating the distribution of oyster habitats along the Pulicat Lake, the second largest brackish water lagoon in India, and investigating their benthic faunal assemblages and functional feeding groups. This study delineated three major reefs (6.70 ha, 5.50 ha, and 2.39 ha areas), and two minor beds (1.10 ha and 0.68 ha areas). Four species of oysters, namely, Magallana bilineata, Saccostrea cuccullata, Isognomon ephippium and Pinctada imbricata fucata were found in the oyster habitats, with M. bilineata being a major reef-forming/ecosystem forming species. Macrofaunal assemblages in the oyster habitats comprised 71 species representing five major phyla belonging to 66 genera under 48 families. Macrofauna were grouped into five Functional Feeding Groups (FFG) considering oyster habitats as a primary food provider. The FFG analysis revealed that the oyster reef/bed in Pulicat Lake is in moderate Ecological Quality Status (EQS). This study is considered very important to know the current extent of oyster reefs and gain a better understanding of the community interactions within oyster habitats and their ecological value to the dwelling species.

Fishery and population characteristics of the Indian white shrimp, Penaeus indicus H. Milne Edwards, 1837 (Decapoda, Dendrobranchiata) in Pulicat Lake, southeast coast of India

Abstract Fishery and population characteristics of the Indian white shrimp, Penaeus indicus, were studied in Pulicat Lake, on the southeast coast of India, using the FiSAT software package. The asymptotic length (), growth coefficient (K) and arbitrary origin of growth (t0) were estimated by the ELEFAN method to be 16.18 cm, 0.60 year−1 and −0.18 year, respectively. The asymptotic length () was calculated as 16.09 cm using the Wetherall method. The growth performance index (Ø′) was found to be 2.19. The mortality parameters Z, F and M were computed to be 3.85, 2.30 and 1.55 year−1, respectively. The pattern of recruitment was observed to be year-round, with a peak from June to September. The total stock, annual catch and exploitation rate for P. indicus were estimated to be 1518.43 tonnes, 809.3 tonnes, and 0.59 year−1, respectively. The estimated Maximum Sustainable Yield (MSY) was found to be 131.95 tonnes less than the annual catch. The stock of P. indicus was found to be over-exploited, so it is suggested that the effort level be reduced by 16.3% in order to sustain this resource in Pulicat Lake.

Geochemometrics of primordial radionuclides and their potential radiological risk in coastal sediments of Southeast Coast of India

In recent years, the contamination of the earth's materials with radioactive elements as naturally occurring radioactive material has been a source of concern. This study is aimed at the environmental radioactivity of beach sediments and the gamma dose levels along the south-eastern coastal region of the Indian subcontinent, from the Palar River mouth (Kadalur Kuppam) to the Pulicat Lake or Pazhaverkadu coast. Furthermore, to analyze the gamma dosage level, as well as the spatial variation of the activity concentrations of 238U, 232Th, and 4 K, as well as the acid-leachable trace elements Ni, Pb, Mn, Zn, Cu, Co, Fe, and Cr in coastal sediments. In addition, radiological risk and hazard indices are assessed in the study domain. The MiniTRACE CSDF survey meter was used to determine the ambient gamma dose level and the activity concentration of primordial radionuclides (238U, 232Th, and 4 K) was quantified using gamma-ray spectroscopy with a NaI (Tl) detector, as well as trace elements studied in atomic absorption spectroscopy. The primordial radionuclides activity concentration (238U, 232Th, and 4 K) in collected coastal sediments of the proposed region were found in the range of ≤3–1953, ≤3–1180, and 41–753 Bq/kg, respectively. The annual effective dose rate was found in the order of 4 K > 232Th > 238U. Based on the geochemometric approach, the data collected for various radiological parameters were combined with radiological risk indices, and trace element concentrations were compared on a regional and global scale. The current study could provide a new research pathway in the areas of coastal monitoring, environmental health, and radiation safety measures.

SEASONAL VARIATION INFLUENCES GLUTATHIONE MEDIATED ANTIOXIDANTS IN Donax incarnatus COLLECTED FROM THE TWO SOUTH INDIAN COASTAL REGIONS

Bivalves comprise the major marine fishery resource; as they are rich in biochemical composition and high nutritional values. The present work deals with studying seasonal variations in the glutathione mediated antioxidant in the edible clam Donax incarnatus collected from coastal region of muttukadu-kovalam estuary and Pulicat lake during period of one year, from May’ 2021 to April 2022. The changes were assessed in relation to the antioxidant components and the level of heavy metal accumulation. Obtained data indicated seasonal variations in the levels of antioxidant markers (reduced glutathione (GSH) content, glutathione peroxidise and glutathione s transferase (GST) activities and the concentrations of heavy metals (Fe, Pb, Cu, Cd and Co) in the bivalves were high during post monsoon season and the lowest values during monsoon. A seasonal variation in the levels of antioxidant components was observed. Among the antioxidant components GST activity was significantly modulated and has significant correlation with the heavy metal accumulation. It therefore appears that bioaccumulation of heavy metals could play a crucial role in regulating the antioxidant components of tissues of Donax species.

Feeding Congregation of the Near-threatened Spot-billed Pelican Pelecanus philippensis in Pulicat lake, Andhra Pradesh, India

Feeding Congregation of the Near-threatened Spot-billed Pelican Pelecanus philippensis in Pulicat lake, Andhra Pradesh, India

Heavy metal accumulation in selected fish species from Pulicat Lake, India, and health risk assessment

Heavy metal pollution in aquatic systems has become a major problem worldwide. The present study was designed to assess bioaccumulation of metals, Cu, Zn, Pb, and Cr, in fish species such as Lutjanus fulviflamma, Chanos chanos, Arius sp., and Terapon jarbua, commonly present in the Pulicat Lake, a brackish water ecosystem located in north Chennai coastal region, southeast India. Mean concentration of Cu and Cr in the sediment samples were 123.1μg/g and 90.1μg/g, respectively. The order of metal prevalence in water and sediment samples were Pb>Cr>Zn>Cu and Cu>Cr>Pb>Zn, respectively. However, in fish samples, the order of metal accumulation was Cu>Cr>Zn>Pb. Mean concentration of Cu in L. fulviflamma, C. chanos, Arius sp., and T. jarbua was 10.5μg/g, 25.5μg/g, 19.0μg/g, and 23.6μg/g, respectively. Mean Cr concentration in the animals varied from 1.19μg/g to 23.1μg/g with highest accumulation in the liver of Arius sp. In general, maximum accumulation of metals is mostly observed in the gills of the organisms. Although the concentration of Cu and Cr in the muscles was above World Health Organization’s permissible limit, the Estimated Daily Intake values were below the standard reference dose which means that the muscle tissues of the fishes are safe for human consumption.

Demographic characteristics and stock assessment of the giant tiger prawn, Penaeus monodon Fabricius, 1798 (Decapoda, Dendrobranchiata) in Pulicat Lake, southeast coast of India

Abstract Demographic characteristics and stock status of the giant tiger prawn, Penaeus monodon were investigated in Pulicat Lake, southeast coast of India, using the FiSAT II software package. The asymptotic length () and growth coefficient (K) were estimated as 20.44 cm and 0.90 year−1, respectively, by the ELEFAN method. The growth performance index (Ø′) was calculated as 2.575. The mortality parameters Z, F and M were computed to be 3.70, 2.15 and 1.55 year−1, respectively. The recruitment pattern was found to be continuous throughout the year with a peak in June and July. The estimated MSY and annual catch were 81.90 tonnes and 95.18 tonnes, respectively. The current exploitation rate (E) was found to be relatively higher than the optimum level. Hence it is recommended that the current effort level be decreased by 13.9% in order to sustain the fishery of this particular species in Pulicat Lake.

Resting and roosting requirements of the near - threatened spot-billed pelican Pelecanus philippensis Gmelin 1789, in Pulicat Lake, Andhra Pradesh, India

Resting and roosting requirements of the near - threatened spot-billed pelican Pelecanus philippensis Gmelin 1789, in Pulicat Lake, Andhra Pradesh, India

Character-based Diagnostic Keys, Molecular Identification and Phylogenetic Relationships of Fishes based on Mitochondrial Gene from Pulicat Lake, India: A Tool for Conservation and Fishery Management Purposes

Background: Pulicat Lake is one of India’s most valuable ecosystems. Correct species identification is essential for the conservation and management of finite resources. Molecular signatures and character-based keys could be used for faster identification. This will be a powerful tool to obtain a significant amount of accurate information quickly and conveniently and could be used for forensic applications and the conservation of fish in Indian waters. Methods: In addition to morphological identification, the species were identified using various approaches, such as Neighbour-joining (NJ), Maximum Likelihood (ML) trees and the Character-based method. For each species, the LOGic (BLOG 2.0) DNA Barcode analysis method was used to identify different positions of key diagnostic nucleotides in a given set. Result: DNA barcodes were generated from twenty-nine species of fish representing seven orders, 26 genera and 21 families in this study. The current study’s findings show that the 16S rRNA barcodes facilitated successful fish species identification and also provided phylogenetic information to differentiate the fishes. The character-based molecular diagnostic keys for fishes were also developed in-silico from the data set comprising 393 mitochondrial 16S rRNA sequences including the sequences generated in the present study and other published resources.

Pollution Indicator Potential of amphipods from Pulicat Lake, Tamil Nadu, South East Coast of India

Heavy metals are naturally occurring elements that have a high atomic weight and a density at least 5 times greater than that of water. In recent years their concentrations were found to be raised in coastal ecosystems, as a result aquatic organisms were exposed to elevated levels of heavy metals. This study deals with the assessment of heavy metals (arsenic, lead, chromium, cadmium and mercury) in water, sediment and amphipods from four different ecosystems of Pulicat lake. The accumulation of heavy metals in water is high during monsoon and low in summer. Whereas, in sediments and amphipods the level is high in post monsoon and low in summer. In water, lead is high followed by arsenic, chromium, mercury and cadmium. In sediment and amphipods, cadmium were found to be high and mercury at lower rates. The metals enters into the Pulicat lake during monsoon in the waters and deposited during post monsoon seasons into the sediments and finally get accumulated in the body of amphipods.

Quality assessment of Physico-chemical parametersin Drinking Water at Pulicat Lake Fishermen Villages

In recent trends water pollution plays a major role in human health and life threatening issues both directly and indirectly related with water utility. Present study based on the analysis of physiochemical parameters in drinking water supplies in various fishermen villages Sathankuppam, Edamani, Thoniravu, Pulicat, Goonankuppam, Arangamkuppam, Vairavankuppam and Koraikuppam around fishermen villages of Pulicat lake. Physiochemical parameters like pH, total dissolved solids, total suspended solids, conductivity and turbidity were recorded from the drinking water samples. Presence of minerals and heavy metals and total bacterial count were also investigated in the water sample. Results show highest value noticed in pH (8.17) at Vairavankuppam, TDS (1589 ppm), TSS (203.1ppm) and conductivity (2788 µs) in Goonankuppam and turbidity (2NTU) from Thoniravu and Goonankuppam. The concentration of minerals, heavy metals and bacterial contamination also monitored. Based on the water quality results it proves to be not good for the domestic usage. More knowledge and awareness are needed for the public to avoid water borne diseases.

Influence of salinity on the meiofaunal distribution in a hypersaline lake along the southeast coast of India.

The present study highlights that seasonal salinity variability plays a significant role in meiobenthic distribution with special reference to nematode assemblages. Sediment and water samples were collected from Pulicat Lake, a hypersaline lake along the southeast coast of India during two seasons (Southwest Monsoon (SWM) and Northeast Monsoon (NEM)). Based on the salinity distribution, the lake is categorized into four regions, viz., southern inlet, central region, middle inlet, and northern inlet. Meiobenthic abundance was higher during SWM (226-12,206 Ind/10 cm2) than in NEM (640-10,424 Ind/10 cm2). The meiofaunal abundance was high in the central region during both the seasons, followed by the southern, northern, and middle inlet. The nematode was the dominant meiobenthic group, followed by copepod, polychaete, and foraminifera. Due to high organic matter, the central region was dominated by deposit feeding nematode species like Halalaimus longicaudatus and Terschellingia longicaudata. The southern and northern regions were dominated by free-living nematodes Rhabditis olitoria, Mesorhabditis capitata, Mononochus bastian, Paramononchus sp., Piranchulus sp., and Diploscapter cylindricus. Oncholaimus sp., a hypersaline indicator species, was reported from the middle inlet location. Statistical analysis suggests salinity as a critical parameter for the distribution and diversity of nematodes.

Identification and Characterization of Micro and Mesoplastics Isolated from Commercially Important Marine Fishes of Pulicat Lake, Tamil Nadu, India

The investigation of microplastics have been carried out among the commercially important marine fishes at Pulicat lake waters. The gastrointestinal tract of fishes were isolated and experimented for further analysis to detect the presence of microplastics. The fishes viz., Nemipterus japonicus, Mugil cephalus, Scomberomorus guttatus, Terapon puta, Sardinella longiceps, Caranx ignobilis, Stolephorus indicus, Rastrelliger kanagurta, Eleuthronema tetradactylum, Alectis indica, Leiognathus sp., Trichiurus lepturus, Trachurus lathamni, Selaroides leptolepis and Terapon jarbua were examined in this study. The microplastics samples were confirmed with BrukerAlpha FTIR ATR spectrophotometer in order to confirm plastics functional groups. Out of the 16 plastic particles isolated, 8 particles were mesoplastics and the rest of them were microplastics. The FTIR-ATR peaks were confirmed C-H stretching and N- H stretching (polyamide), C-H stretching, O-H stretching or N-H stretching (poly lactic acid), CH group (polythene) and C-H stretching, C=O stretching and C-O stretching (polyester). The presence of microplastics in the fish from the sampling locations may be due to unmonitored dumping of wastes in the water. The presence of microplastics may affect the growth of fish which leads to poor commercial value. The future research should be aimed to evaluate the impact and the risk of microplastics to the fishes, environment as well as human beings and to create awareness among the people, as well as the fishermen.

Effect of seasonal variation on the diversity of zooplankton in Pulicat Lake, Thiruvallur District, Tamil Nadu, India, and the possible future consequences of climate change

Effect of seasonal variation on the diversity of zooplankton in Pulicat Lake, Thiruvallur District, Tamil Nadu, India, and the possible future consequences of climate change