Southeast Coast Of Tamil Nadu Research Articles

Length-weight Relationship and Condition Factors of Seven Penaeus Shrimp Species along the Southeast Coast of Tamil Nadu (Southern India)

Background: The present study of the length-weight relationship and condition factors of seven shrimp species on the southeast coast of Tamil Nadu between July (2022) and February (2023) also estimated the coefficient of determination (r2). Methods: For shrimp species, the length-weight relationship shows some species have significant positive coefficients which have a determination by (r2 greater than 0.5) like Penaeus indicus, Penaeus mergiuensis, Penaeus canaliculatus, Penaeus latisulcatus, Penaeus monodon, some species have shown negative as (r2 greater than 0.5) value like Penaeus japonicas and Penaeus semisulcatus. Result: All shrimp species have heterogeneity evident in intercept (a). The growth exponent (b) varied between 0.278 and 2.289 and it significantly (p=0.05) deviated from the value of less than 3 which denoted negative allometric growth for all Penaeus shrimp species.

Effect of Seasonal Variations in Hematology, Biochemical, Immunity Constituents in Mugil cephalus, Chano chanos, and Arius arius on Southeast Coast of Tamil Nadu, India

The assessment of the effect of seasonal variations on health, hematology, and serum biochemical components of three marine teleost fishes, Mugil cephalus, Chanos chanos, and Arius arius from Kovalam, East Coast Road, Southeast coast of Tamil Nadu, India. The objectives of the study pointed out the effect of seasonal variation on fish health and immunity. During summer and pre-monsoon, a total of 20 samples were collected from each sample, and hematological, biochemical, immunity parameters, and fish health were considered. M. cephalus (L-23.86±1.03; W-171.22±35.42) C. chanos, (L-22.36±1.17; W-163.03±33.32) and A. arius (L-22.62±1.08; W-168.72±35.04) have different length and weight. The WBC, RBC, Hb, and HCT were higher during summer in M. cephalus, C. chanos, and A. arius likewise, these parameters were lower in the pre-monsoon period (P<0.05). The MCV, MCH, MCHC, and ESR of all three species were higher in the pre-monsoon whereas in the summer they decreased. Likewise, leukocytes such as neutrophils, monocytes, lymphocytes, eosinophils, and thrombocytes show minimum levels in the pre-monsoon and attain maximum levels in the summer. Most importantly, in the summer, serum components protein and glucose were higher, while cholesterol and urea were lower, and vice versa. Although IgM and IgG levels (P<0.05) were higher in the summer and declined in the pre-monsoon season. In the lysozyme assay, respiratory burst activity (NBT) (P<0.05) reveals a higher concentration in the pre-monsoon and was lower in the summer. A total of thirteen hematological parameters, six biochemical, and two immunological parameters, and lysozyme and NBT activities showed a significant relationship with fish health throughout the seasonal changes. Based on the findings, M. cephalus shows maximum variations in length, weight, hematology, biochemical, and immunity levels, whereas C. chanos showed minimum variations. Hence the report indicates the seasons mainly impact the physiological status of the fish species.

Nivar cyclonic impacts on mollusk habitat destruction in Parangipettai, southeast coast of Tamil Nadu, India: A case study

Tropical storms form in the Bay of Bengal every year during the pre-monsoon season, affecting the coastal communities and the marine ecosystem. On November 25, 2020, severe cyclone Nivar impacted the southeast coast of Tamil Nadu, causing massive damage to marine benthic species. The study found that the Nivar cyclone's high velocity wind impacted tidal currents and damaged sediment compartments. This phenomenonhas immensely affected the benthic communities of Mudasalodai, Parangipettai, Puthupettai, Samiyarpettai, and Kumarapettai. Post-Nivar cyclone observations revealed massive bivalve and gastropod mortality. The two molluscan species lost their habitats due to the tremendous cyclone effect. More than 1 lakh Mactra violacea were emigrated from Parangipettai and 5 lakh Turritella acutangula and T. attenuata were emigrated from Samiyarpettai. Thus, the Nivar cyclone severely damaged mollusk habitats along India's southeast coast. The severe cyclonic storm Nivar disrupted the southeast coast of India, with losses amounting to over $600 million.

Influence of Bottom Water Parameters on the Distribution of Benthic Foraminifera from the Gulf of Mannar, Off Tiruchendur, Southeast Coast of India

Foraminifera are found in all marine environments, but they are very particular about the congenial environment for their reproduction, diversity and abundance. To understand the influence of bottom water parameters on the distribution of foraminifera from the shallow shelf region of Bay of Bengal, off Tiruchendur, Southeast Coast of Tamil Nadu, sediment and bottom water samples were collected at 27 stations, along three traverses viz. from off Veerapandianpattinam, off Tiruchendur and from off Alandurai, ranging in depths from 1.6m to 18.5m. The samples were collected during three seasons representing, summer (May 2016), pre monsoon (October 2016) and winter (January 2017) and thus the total samples amounted to 81. A total of 105 species of foraminifera have been identified from 47 genera, 32 families, 16 superfamilies and 4suborders. Among these 105 foraminiferal species, five were found to be widespread and abundant viz. Ammonia beccarii, A. tepida, Asterorotalia inflata, Nonioniodes boueanum and Quinqueloculina seminulam. Various bottom water parameters such as temperature, salinity, dissolved oxygen and pH were determined and correlated with the foraminiferal population. Temporally, higher temperature, salinity, dissolved oxygen and pH of bottom water observed during summer (May 2016) were congenial for higher population in the study area. Optimum conditions for the higher population and abundance of foraminifera are: Temperature: > 32.0°C, Dissolved oxygen: >6.0 mg/l, Salinity: >32 ppt and pH>8.1.

Mass mortality of regular sea urchin Salmacis virgulata L. Agassiz and Desor, 1846 at Dhanushkodi, Southeast coast of Tamil Nadu, Gulf of Mannar, India

Mass mortality of sea urchin, Salmacis virgulata scattered over the periphery of Dhanushkodi beach, was observed on February 13, 2019. More than 100 numbers of recently dead and dying specimens were found within a 10 m2 area on the sandy beach. Beach profiles indicated several hundreds of exoskeletons of previously dead S. virgulata were washed ashore and buried in sand and withering seagrass. The causative agent responsible for mass mortality of S. virgulata is yet to be discovered. However, observations on wave approach toward shore indicated possible evidence that it could be due to a combination of strong nearshore waves and currents. This observation raises a critical research concern to investigate etiology of S. virgulata for species conservation.

Diversity and Molecular Characterization of Marine Halophilic Bacteria from Southeast Coast of India

The marine environment envelops an enormous natural assorted diversity and can be considered as an unexplored domain. Diversion of biodiversity is an important part of ensuring the safety and stability of the marine ecosystem. The present study aimed to isolate and characterized the marine halophilic bacteria from the Southeast coast of Tamil Nadu, India. Based on colony morphology the isolated bacteria was characterized by gram staining and biochemical test. The isolated marine halophilic bacteria were screened and identified with a phylogenetic analysis of 16S rRNA gene sequence determined. The result revealed the phylogenetic analysis using 16S rRNA sequence indicated that 6 bacterial isolates belong to Gram-positive phylum of Firmicutes (CARE-V2 Bacillus flexus, CARE-V12 Virgibacillus halodenitrificans, CARE-V17 Virgibacillus salaries, CARE-V29 Jeotgalicoccus huakuii, CARE-V33 Oceanobacillus iheyensis, and CARE-V34 Virgibacillus sp), and 6 bacterial strains accord to Gram-negative phylum of proteobacteria (CARE-V3 Halomonas sp, CARE-V5 Oceanimonas sp, CARE-V9 Bacterium, CARE-V10 Halomonas salifodinae, CARE-V14 Halomonas venusta, CARE-V31 Salinivibrio sp). This study summarized the marine halophilic bacteria and the diversity of marine microorganisms from the Southeast coast of Tamil Nadu.

Occurrence of fine scale to massive green tides in coastal waters of Palk Bay and Gulf of Mannar regions, southeast coast of Tamil Nadu, India

Occurrence of fine scale to massive green tides in coastal waters of Palk Bay and Gulf of Mannar regions, southeast coast of Tamil Nadu, India

Current biodiversity of Mandapam group of Islands in Gulf of Mannar Marine Biosphere Reserve, Southeast coast of Tamil Nadu, India

The global climate change is known to involve in the decline of biodiversity from different ecosystems, including coral reefs worldwide. The spatial distribution of reef associated flora and fauna in the Gulf of Mannar (GoM) Marine Biosphere Reserve (GOMMBR) are declined due to damage of coral reefs by three major global problems observed in coral reefs, pertaining to frequent bleaching events, sedimentation and overwhelming algal communities. The occurrence of rich biodiversity in reef areas indicates the healthy condition of an iconic reef ecosystem. In this study, to assess the health status of coral reefs in Mandapam group of Islands under GoM, the diversity and distribution patterns of species composition assembled in reefs at seven Islands were analyzed. In 2019, summer temperature range was exceeded between 32 to 36 °C than usual range 28 to 30 °C, which resulted again massive coral bleaching in GoM. Statistical analysis revealed the high diversity of macroalgae in all the reef sites at Mandapam group Islands. Considerably, dead reefs in Mandapam group Islands represent 90% of algal communities and very less to scarce faunal diversity. While, faunal diversity was well diversified in the live coral cover areas and reefs with less macroalgal assemblage. This assessment provides current reef biodiversity data for gaining further insights into complex spatial distribution patterns of reef biota in GoM, and this will support the authorities to plan conservation efforts and to support livelihood of local fisher folk community.

BIOSYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES FROM MARINE MACROSCOPIC RED SEAWEED HALYMENIA PORPHYROIDES BOERGESEN (CRYPTON) AND ITS ANTIFUNGAL EFFICACY AGAINST DERMATOPHYTIC AND NON-DERMATOPHYTIC FUNGI

Objective: The current study illustrates the biosynthesis of economically scalable and energy efficient colloidal silver nanoparticles (AgNPs) from marine red seaweed Halymenia porphyroides Boergesen (Crypton) collected from Southeast coast of Tamil Nadu, India, and their antifungal efficacy against dermatophytic and non-dermatophytic fungi was evaluated.
 Methods: The biosynthesis of silver nanoparticles from marine macroscopic red seaweed H. porphyroides Boergesen were synthesized by green synthesis method and characterized by UV–Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction, thermogravimetric analysis (TGA), scanning electron microscope (SEM), and transmission electron microscopy (TEM). The efficacy of silver nanoparticles against dermatophytic and non-dermatophytic fungi was performed by disk diffusion method.
 Results: The presence of silver nanoparticles with an average size between 34.3 and 80 nm and exhibiting face-centered cubic structure was confirmed. SEM revealed the morphology of the nanoparticles as spherical and TEM exhibited the nanoparticle distribution. The FT-IR spectra confirmed the presence of potential biomolecules in the seaweed crude extract which is responsible for reducing and capping the bioreduced silver nanoparticles. The UV absorption spectra at 430.5 nm revealed the characteristic spectra of the silver nanoparticles. The purity and the thermal stability of silver nanoparticles were revealed by TGA. Silver nanoparticles showed significant efficacy against dermatophytes and Rhizopus microsporus among non-dermatophytes.
 Conclusion: Intermediate efficacy was observed against dermatophytes and among non-dermatophytic fungi R. microsporus exhibited better efficacy, whereas Aspergillus flavus were resistant to the biosynthesized silver nanoparticle.

Seasonal studies on in situ coral transplantation in the Gulf of Mannar Marine Biosphere Reserve, Southeast coast of Tamil Nadu, India

Since past three decades, coral reefs of the world are degrading at large scales due to climate change and through combination of anthropogenic and natural disturbances. Coral reefs in the 21 islands of Gulf of Mannar Marine Biosphere Reserve, Southeast coast of Tamil Nadu, India are also greatly damaged by frequent bleaching events, destructive fishing, invasive algal assemblage, sedimentation, diseases, and destructive waves and currents. To facilitate the restoration of these habitats, an extensive artificial restoration of corals has been implemented as a counter measurement. This conservation practice will help to increases the live coral covers, rebuild the destroyed coral reefs, and protect the reef biodiversity. The present study underwater experiments were revealed that profuse growths of transplanted corals are dependent on coral species and the study sites. There was significant differences in seasonal growth rate at northern side of Hare Island (p = .03), where the maximum mean Acropora coral growth rate around 11.75 cm was observed during summer from initial mean growth 7.65 cm. Similarly, significant variation in growth rate was observed during monsoon between naturally recruited and transplanted corals (p = .02), where naturally recruited coral colonies, and transplanted coral colonies were displayed the maximum mean growth rates as 11.5 cm, and 7.5 cm respectively in two months,. Significance seasonal influence on growth rates of transplanted coral was observed (p = .01). Relatively, Acropora corals have showed faster growth rates and also resistance to environmental influences such as algal invasion, sedimentation, turbidity, and bleaching events.

Phytochemical, Amino Acid, Fatty Acid and Vitamin Investigation of Marine Seaweeds Colpomenia Sinuosa and Halymenia Porphyroides Collected Along Southeast Coast of Tamilnadu, India

Seaweeds are marine macroscopic algae which are considered as the important living marine organisms with high nutritive value and rich bio-active compounds present in the ocean. In the current study the phytochemical, amino acid, fatty acid and vitamin profile analysis of the seaweeds were conducted which were collected along the south east coast of India. The marine brown macro alga Colpomenia sinuosa (Mertens ex Roth) Derbes and Solier as well as the marine red alga Halymenia poryphyroides Boergesen were used in this study. The relationship between the nutritive components and the variation between phytochemical, amino acid, fatty acid and vitamin profile were mainly analyzed in the current study. The present analysis revealed that phytochemical contents like alkaloids, triterpenoids, steroids and glycosides were present in higher amounts in marine red alga Halymenia porphyroides compared to the marine brown alga Colpomenia sinuosa. Similarly the amino acid analysis showed higher percentage in marine red alga Halymenia porphyroides when compared to the marine brown alga Colpomenia sinuosa. The fatty acid profile also revealed higher content in Halymenia porphyroides when compared to Colpomenia sinuosa. On the contrary the vitamin profile analysis revealed higher amounts of vitamins content in Colpomenia sinuosa rather than Halymenia porphyroides. The presence of high phytochemical, amino acid, fatty acid constituents in Halymenia porphyroides makes this seaweed more important when compared Colpomenia sinuosa which were rich in vitamin content and can be used as an important vitamin source for human and animal diet.

Elevated sea surface temperature triggers massive bloom of Protoperidinium pallidum in Tuticorin coastal waters, southeast coast of Tamil Nadu, India

Elevated sea surface temperature triggers massive bloom of Protoperidinium pallidum in Tuticorin coastal waters, southeast coast of Tamil Nadu, India

Assessment of gamma radiation and associated radiation hazards in coastal sediments of south east coast of Tamilnadu, India with statistical approach

Gamma spectroscopy was performed to determine the concentrations of 226Ra, 232Th and 40K in sediment samples collected from Periyakalapet to Parangaipettai, East coast of Tamilnadu. The activity concentrations were determined by direct counting using a hyper pure germanium (HPGe) detector inter phased with a multi channel analyzer (MCA). The average activity concentrations of the corresponding nuclides were 30.81 Bq kg−1 for 226Ra, 85.67 Bq kg−1 for 232Th and 425.72 Bq kg−1 for 40K. The average activity concentration of 232Th and 40K are slightly higher and 226Ra is lower than world average values. The radiation hazard indices namely Radium Equivalent Activity (Raeq) Absorbed Gamma Dose Rate (DR), Annual Effective Dose Rate (HR), Representative Level Index (RLI), Annual Gonadal Dose Equivalent (AGDE), Internal Hazard Index (Hin) and External Hazard index (Hex) are calculated and compared with the previously reported data. The extracted values are comparable to the recommended values and they all fall within the safety limits. Hence harmful radiation effects are not posed to the public and tourists going to the beaches for recreation or to the fishermen involved in their activities in the area as a result of the natural radioactivity of sediments. Multivariate Statistical analyses were carried out between the parameters obtained from the radioactivity to know the existing relations and to study the spatial distribution of radionuclides.

A REVIEW ON VARIATION OF NATURAL RADIOACTIVITY ALONG THE SOUTHEAST COAST OF TAMIL NADU FOR THE PAST 4 DECADES (1974-2016).

This review deals with natural radioactivity variation along the southeast coast of Tamil Nadu for the past four decades (1974-2016). About 40 research works have been conducted along the coast since 1974 in various environmental matrices using a variety of experimental methods. For these measurements researchers are adopted different experimental methods. The measured gamma dose rate ranged from 30 to 8700 nGy/h. The mean specific activity of 238U, 232Th and 40K was found to be 58.8 ± 28.7, 465.2 ± 147.3 and 311.2 ± 27.8 Bq/kg, respectively. The calculated annual exposure rate ranged from 0.29 to 12.8 mSv/y with the mean value of 3.7 mSv/y which is above the global average of 2.4 mSv/y as reported by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) (Report to General Assembly, Annex B Exposures of the public and workers from various sources of radiation. United Nations, New York (2008)). Plant food items recorded low 210Po activities as compared to seafood organisms. Grain size, season and place of sampling have a decisive bearing on coastal radioactivity. Therefore, it is concluded from the review data that there is an appreciable elevation in background radiation level in the coastal region. This review suggests that new radiological surveys using improved methodology that cover the entire coastal stretch are needed.

Seasonal Variation in Nearshore Wave Characteristics off Cuddalore, Southeast Coast of Tamil Nadu, India

Wave data collected using wave rider buoy between January 2010 and January 2011 off Cuddalore coast, Tamil Nadu, India, have been analysed season-wise in this study. Wave steepness method was used for the separation of sea and swell wave parameters. Also parameters such as significant wave height of total wave, sea and swell (H s , H sw and H ss ), zero crossing periods (T z , T sw and T ss ) and mean wave directions (θ, θ sw and θ ss ) have been studied. The study shows a distinct shift in sea wave direction of about 90° between June and October as well as November and February. Throughout the year, the predominant swell direction remained around 135°. The contribution in total H s by H sw was 76% and the remaining 24% by H ss in the yearly cycle. The sea wave height was dominant by more than 90% during November to May. Regression analysis showed good positive Pearson's correlation of 0.94 between Hs and H sw ; however, it was 0.65 between H s and H ss . The maximum and significant wave heights of 5.7 and 2.7 m were recorded during cyclone Jal on 7 November 2010.

Heavy metal and potential ecological risk assessment in sedimentscollected from Poombuhar to Karaikal Coast of Tamilnadu using Energy dispersive X-ray fluorescence (EDXRF) technique

Heavy metal concentrations in coastal sediments from Poombuhar to Karaikal of South East Coast of Tamilnadu were conducted to evaluate the level of contamination. The metal concentrations were analyzed in sediment samples using Energy dispersive X-ray fluorescence technique. The determined mean metal concentration is in the order of Ca>Ti>K>Al>Fe>Mg>Zn>Ni>Cr>V>Mn>Co The heavy metals contamination in sediments is assessed using pollution indices like Contamination factor (Cf), Contamination Degree (Cd), Modified Degree of Contamination (mCd) and potential contamination index (Cp). The environmental risks of the heavy metals in sediments assessed by the potential ecological risk factor. From the analysis, sediments are polluted by Ti, V, Cr, Mn, Ca and Pb due to anthropogenic activites (fishermen boat activites) in the study area. The results of this study would provide a useful aid for sustainable marine management in the region.

Petroleum hydrocarbon concentrations in marine sediments along Nagapattinam – Pondicherry coastal waters, Southeast coast of India

In this present study, petroleum hydrocarbons were statistically analyzed in three different coastal sediment cores viz., (N1, P1 and P2) from the Southeast coast of Tamil Nadu, India to examine the viability of PHCs. The significant positive relationship between mud (silt+clay+sand) and PHC unveiled that high specific surface of area of mud content raise the level of PHCs. Cluster analysis was used to discriminate the sediment samples based on their degree of contamination. The present study shows that instead of expensive and destructive PHC chemical methods, magnetic susceptibility is found to be a suitable, cheap and rapid method for detailed study of PHC in marine sediments. This baseline PHCs data can be used for regular ecological monitoring and effective management for the mining and tourism related activities in the coastal ecosystem.

HEAVY METALS IN BRACKISH WATER ZOOPLANKTON AT NAGORE COASTAL REGION, SOUTHEAST COAST OF TAMILNADU.

20Dec 2016 HEAVY METALS IN BRACKISH WATER ZOOPLANKTON AT NAGORE COASTAL REGION, SOUTHEAST COAST OF TAMILNADU. R. Bhuvaneswari and Serfoji. P. Post Graduate and Research Department of Zoology, Government Arts College (Autonomous), Kumbakonam, India.

Geochemical variations of core sediments of Pichavaram Lagoon, southeast coast of Tamil Nadu, India: a provenance and paleoenvironmental study

The present study aims to identify the natural and anthropogenic imprints left by the accumulation of elements and to determine/identify the current level of enrichment of major oxides in the Pichavaram mangrove sediments. Pichavaram mangrove is a dynamic intertidal environment lying in between the Vellar and Coleroon estuaries in the Cauvery delta along the east coast of India. In the present study, results of texture studies reveal highly variable depositional environment in upper and lower portion of Core 1 and middle portion of Core 2. In both the cores, decrease in grain size is observed in the upper portion which may suggest that the sediments in the upper portion were deposited at low energy condition. Mn/Al, Mg/Al, Ca/Al, Ti/Al, P/Al and K/Al ratios are found to be low in the both the core samples. Ti elemental ratio is lower in both core samples indicating that Ti concentrations in marine sediments are the best indicators of lithogenous material flux to the marine environment. The concentration of various elements in the core can be summarized as Si > Al > Fe > Mn > Mg > Ca > Ti > P > K. The PIA values of Core 1 indicate that the sediments were derived from predominant weathering up to 40 cm and the remaining sediments derived from unweathered matrices. Plagioclase Index of Alteration (PIA) values of most of the downcore samples of Core 2 are found to be more than 40 suggesting the predominance of weathering activity. Low PIA values are observed at the depth of 54–70 cm indicating the moderately weathered nature of the sediments in the study area. Positive correlation between Fe and Mg and their negative relationship with silica indicates the presence of ferromagnesian debris in top of the sediments. Major oxide geochemistry indicates a heterogeneous and moderately weathered to unweathered source for the sediments of the present study area.

Trace element concentration in surface sediments of Palk Strait, southeast coast of Tamil Nadu, India

The present work was carried to decipher the trace element accumulation in surface sediments of Palk Strait, southeast coast of Tamil Nadu, India. The elemental concentration and correlation results suggest that fine fractions with CaCO3 content followed by organic matter (OM) of the surface sediments control the trace element accumulation in the study area. In addition, Fe and Mn concentration is chiefly contributed from riverine process and controlled by the mangrove ecosystem. The other elements are derived into marine environment through confluence of untreated industrial pollutants into the river system. The EF result shows that the studied marine sediments are enriched by Ni, Mn, Cu, Pb, Cd, Cr, followed by Zn. The order of the pollution intensity with respect to geo-accumulation index suggests the following ascending order: Ni>Mn>Fe>Cu>Pb>Cd>Cr>Zn. Pollution Load Index (PLI) values reveal that all the samples are falling under moderately to unpolluted category.