Impact of bottom trawling on water and sediment characteristics of Cuddalore and Parangipettai coastal waters

639-646The present study was carried out to understand the impact of bottom trawling on the hydrographic, nutrient and sediment characteristics of Cuddalore and Parangipettai coastal waters during April 2014–March 2015. The present study addressed the impact of trawling on the sediment re-suspension, biochemical composition and bioavailability of organic matter in two coastal waters off Bay of Bengal. Sampling was carried out in four depth stations at 10, 20, 30, 40 m. Water and sediment samples were collected before and after trawling. The variations in total organic carbon and sediment nutrients were prominent in relation to stations and seasons. Pronounced changes were observed in water nutrients before and after trawling, while there was a minor effect on dissolved oxygen, total organic carbon and sediment nutrients. Conforming to the results, the PCA plot drawn for both the regions also revealed similar trend by the fact that the water nutrients had positive correlation with samples collected after trawling in all the stations, while dissolved oxygen, soil nutrients and total organic carbon showed negative correlation with the samples collected before trawling in all the stations

Occurrence of epibionts in coastal waters of Tamilnadu

920-925Present study provides the distributional records of genera of protozoan ciliates namely Epistylis, Vorticella, Veginicola, Acineta and Tokophyra as epibionts got attached on the body surface of zooplankton such as Labidocera pectinata, Euterpina acutifrons, Pontella danae, Pontella securifer, Corycaus danae, Metis jousseaumei, Disticoulus minor, Lucifer hansei, Tortanus forcipes, Oithona rigida, O.brevicornis and Gastropod veliger collected from Tuticorin and Ennore coastal waters. Five genera of ciliates viz., three peritrichids and two suctorians, were identified and classified within the subclass Peritrichia: Epistylis Ehrenberg, 1830 (Epistylidae), Vaginicola Lamarck, 1816 (Vaginicolidae) and Vorticella Linnaeus, 1767 (Vorticellidae); and Suctoria: Acineta Ehrenberg, 1834 (Acinetidae) and Tokophrya Bütschli, 1889 (Tokophrydae). Data collected suggest that the epibiont attachment on copepods may have a significant impact on the health of the fish population due to the substantial reduction in the population density of the copepods leading to food scarcity for the fish populations which directly depend on them

Utility of benthic diversity in assessing the health of an ecosystem

783-793<span style="font-size:11.0pt;mso-bidi-font-size: 9.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" letter-spacing:-.1pt;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-GB">Impact of thermal plant discharges on benthic community of Tuticorin Bay and Vaan Island was studied during the period of August 2007 to July 2008. Water quality parameters and <span style="font-size:11.0pt;mso-bidi-font-size: 9.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:ta"="" lang="EN-GB">heavy metals such as <span style="font-size:11.0pt;mso-bidi-font-size: 9.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-GB">Cd, Cu, Pb, Ni, Zn and Cr <span style="font-size:11.0pt; mso-bidi-font-size:9.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:ta"="" lang="EN-GB">in sediment<span style="font-size:11.0pt; mso-bidi-font-size:9.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:="" "times="" roman";mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-GB"> were estimated. As regards biological entity, there were four benthic faunal groups, of this; polychaetes topped the list in terms of abundance in both the regions followed by gastropods, crustaceans and bivalves. Faunal density varied from 552 to 10, 311nos. /m2 in Tuticorin Bay and 355 to 15, 447nos./m2 in Vaan Island. Maximum density was found during summer season and minimum during monsoon season. Diversity and richness values were also more in Vaan Island than Tuticorin Bay. Cluster and MDS plots drawn showed that stations of Tuticorin Bay and Vaan Island formed group themselves indicating dissimilarity in their faunal composition and its abundance. BIO-ENV method revealed that temperature, pH, copper and zinc in Tuticorin Bay and zinc and salinity in Vaan Island, as best variable combinations influencing the benthic faunal distribution. </span

Influence of environmental parameters on abundance and diversity of phytoplankton in Pichavaram mangroves, southeast coast of India

591-602During the study period, 62 species belonging to three taxa namely diatoms, dinoflagellates, and blue green algae were recorded. Of these three, diatoms were found to be the dominant group with 47 species; dinoflagellates formed next dominant group with 9 species and blue greens came last in the order with 6 species in all the stations. Population density of phytoplankton ranged between 2,350 and 32, 405 Cells/l were identified in Pichavaram mangrove region. Phytoplankton community was analyzed by Univariate and Multivariate statistical techniques. Results of CCA analysis suggested that the environmental parameters such as temperature, salinity, and a few nutrients are the key variables in determining the abundance and diversity of phytoplankton community

Effect of bottom trawling on the health of macro benthic community: a graphical technique approach

566-573An attempt was made to study the health assessment of marine environment through graphical technique. Experimental trawling was carried out with the help of a commercial trawler during the study period of one year from January to December 2009. Maximum density of benthic organisms was recorded at 25m & 35m depth. Samples of ‘before and after’ trawling to ascertain whether, they are subjected to any form of disturbances or not, and the results are shown graphically. In these plots, it clearly revealed that the trend observed in ABC plots were on positive side, indicating undisturbed nature of benthic macro fauna. The values on the negative side indicating moderately disturbed. Cluster and MDS also group forming before and after trawling in both the regions

A study to evaluate association of nuclear grooving in benign thyroid lesions with RET/PTC1 and RET/PTC3 gene translocation

Abstract Introduction Papillary thyroid carcinoma (PTC) is the most common malignant lesion of the thyroid characterized by unique histological features like nuclear grooving, nuclear clearing, and intra-nuclear inclusions. However, nuclear grooves are observed even in benign thyroid lesions (BTL) like nodular goiter (NG), Hashimoto's thyroiditis (HT), and follicular adenoma (FA) resulting in diagnostic dilemma of the presence of PTC in such BTL. RET/PTC gene translocation is one of the most common oncogenic rearrangements seen in PTC, known to be associated with nuclear grooving. Among different types of RET/PTC translocations, RET/PTC1 and RET/PTC3 gene translocations are the most common types. These translocations have also been identified in many BTL like hyperplastic nodules and HT. Our study aimed to determine the frequency of nuclear grooving in BTL and evaluate their association with RET/PTC1 and RET/PTC3 gene translocation. Methods Formalin-fixed, paraffin-embedded (FFPE) tissue blocks of NG, HT, and FA were included in the study. The hematoxylin and eosin (H&E) stained sections were evaluated for the presence of nuclear grooving/high power field (hpf) and a scoring of 0 to 3 was used for the number of grooves. Sections of 10 μ thickness were cut and the cells containing the nuclear grooves were picked using Laser-Capture microdissection. About 20 to 50 such cells were microdissected in each of the cases followed by RNA extraction, cDNA conversion, realtime-polymerase chain reaction (RQ-PCR) for RET/PTC1 and RET/PTC3 gene translocation, and the findings were analyzed for statistical significance. Results Out of 87 BTL included in the study, 67 (77.0%) were NG, 12 (13.7%) were HT, and 8 (9.2%) were FA. Thirty-two cases (36.8%) had nuclear grooving with 18 out of 67 NG, 6 out of 12 HT, and all 8 cases of FA showing a varying number of nuclear grooves. A significant association between the number of nuclear grooves with RET/PTC gene translocation (p-value of 0.001) was obtained. A significant association of HT with RET/PTC gene translocation (p-value of 0.038) was observed. RET/PTC1 and RET/PTC3 translocation were seen in 5 out of 87 cases, with HT showing positivity in 2 and FA in 1 case for RET/PTC1 and HT in 1 and FA in 2 cases for RET/PTC3 gene translocation with 1 case of FA being positive for both RET/PTC1 and RET/PTC3 gene translocation. Conclusions The frequency of nuclear grooving among BTLs in our study was 36.8%. Our study shows, that when BTLs, show nuclear grooves, with an increase in the nuclear size, oval and elongated shape, favors the possibility of an underlying genetic aberration like RET/PTC gene translocation, which in turn supports the reporting pathologist to suggest a close follow up of the patients on seeing such nuclear features on cytology or histopathology sample, particularly in HT

Benthic biodiversity in natural <i>vis-a-vis</i> artificially developed mangroves of south east coast of India

1049-1058Benthic biodiversity was compared between natural (Pichavaram) and artificially developed mangrove (Vellar estuary) systems in southeast coast of India. As many as 23 species of benthic macrofauna were recorded in Pichavaram (14 species of polychaetes, 7 species of crustaceans 2 species of molluscs), while 19 species of macrofauna were recorded in Vellar (11 species of polychaetes, 5 species of crustaceans and 3 species of molluscs). Population density varied between the habitats (39 and 3346 nos/m2 in Pichavaram and 39 and 2908 nos/m2 in Vellar). In short, among the faunal groups, crustaceans topped the list in terms of abundance in Pichavaram and polychaetes in Vellar. Calculated diversity indices also varied between these two areas. Species diversity was in the range of 2.47 - 3.17 in Pichavaram and 2.37 - 2.86 in Vellar; species richness ranged from 1.70 to 1.86 in Pichavaram, and from 1.54 to 1.76 in Vellar; species evenness varied from 0.60 to 0.76 in Pichavaram and from 0.59 to 0.71 in Vellar. As observed in the species diversity, taxonomic diversity and phylogenetic diversity values were also more in natural system than those in artificially developed habitat