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Dhaneesh K.V.,Annamalai University | Noushad K.M.,Center for Marine Living Resources and Ecology | Ajith Kumar T.T.,Annamalai University
PLoS ONE | Year: 2012

Estimation of nutrition profile of edible fishes is essential and thus a bio-monitoring study was carried out to find out the nutritional composition of commonly available fishes in Agatti Island water of Lakshadweep Sea. Protein, carbohydrate, lipid, ash, vitamin, amino acid and fatty acid composition in the muscle of ten edible fish species were studied. Proximate analysis revealed that the protein, carbohydrate, lipid and ash contents were high in Thunnus albacares (13.69%), Parupeneus bifasciatus (6.12%), Hyporhamphus dussumieri (6.97%) and T. albacares (1.65%), respectively. Major amino acids were lysine, leucine and methionine, registering 2.84-4.56%, 2.67-4.18% and 2.64-3.91%, respectively. Fatty acid compositions ranged from 31.63% to 38.97% saturated (SFA), 21.99-26.30% monounsaturated (MUFAs), 30.32-35.11% polyunsaturated acids (PUFAs) and 2.86-7.79% branched fatty acids of the total fatty acids. The ω-3 and ω-6 PUFAs were ranged 13.05-21.14% and 6.88-9.82% of the total fatty acids, respectively. Hence, the fishes of Lakshadweep Sea are highly recommended for consumption, since these fishes are highly enriched with nutrition. The results can be used as a baseline data for comparing the various nutritional profiles of fishes in future. © 2012 Dhaneesh et al. Source

Vijayan A.K.,Center for Marine Living Resources and Ecology | Somayajula S.A.,Indian National Center for Ocean Information Services | Somayajula S.A.,Laval University
Oceanologia | Year: 2014

The light absorption properties of a dinoflagellate (Noctiluca scintillans Macartney) bloom in Manila Bay were analysed during the onset of a whole-bay-scale bloom in March 2004. The chlorophyll a concentrations varied over a very wide range from 1.4 μg l-1 to extremely high values of 521 μg l-1. The chlorophyll specific absorption coefficients of phytoplankton (a*ph(λ)) varied significantly in shape and magnitude. The spectrally averaged values of a*ph(λ) varied by two orders of magnitude within and outside the bloom patch. The total suspended solid concentration was high in the middle of the bay (≥ 4 mg l-1). The non-photosynthetic pigment (NPP) index was ~ 0.6 at most of the stations, mainly due to the presence of photoprotective pigments like zeaxanthin, lutein and neoxanthin, which led to variations in the blue absorption maxima of the chlorophyll-specific absorption coefficients. The absorption properties of the accessory pigments were masked owing to the presence of overlapping pigment absorption bands. The fourth derivative of the absorption spectra was able to resolve these overlapping features and enhance the absorption characteristics of prominent accessory pigments. © Polish Academy of Sciences, Institute of Oceanology, 2014. Source

Sabu P.,Center for Marine Living Resources and Ecology | Revichandran C.,National Institute of Oceanography of India
International Journal of Remote Sensing | Year: 2011

The relative importance and contribution of various processes in the total heat budget in the mixed layer of the Arabian Sea Warm Pool (ASWP) during spring intermonsoon (March-April 2004) were studied using in situ observations and satellite data. The evolution of the surface heat budget has been resolved into individual components of advection, vertical mixing, eddy induced diffusion and surface heat fluxes. In the northern part of the warm pool, the surface heat flux is the dominant component in the mixed layer warming while the advection plays a role in spreading the warm water from the coastal region to the far west. In the southern part of the warm pool, the eddy induced horizontal mixing provides a substantial amount of heat spreading that influences the mixed layer temperature evolution. © 2011 Taylor & Francis. Source

Naik R.K.,National Institute of Oceanography of India | George J.V.,National Institute of Oceanography of India | Soares M.A.,National Institute of Oceanography of India | Devi A.,Center for Marine Living Resources and Ecology | And 5 more authors.
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2015

The juncture of the Agulhas Return Front (ARF) and Subtropical Front (STF) in the Indian Ocean sector of Southern Ocean (SO) is characterized by high mesoscale turbulence, which results in sporadic, short lived phytoplankton proliferation. The biota, mainly the phytoplankton community from such a complex hydrodynamic region and its response to the mesoscale turbulence, are areas of interest for investigation. Hence, during the sixth Indian expedition to SO, a two-day time series was occupied at the ARF and STF merged region (40°S 58°30'E) from 13 to 15 January, 2012. The vertical profiles of phytoplankton (based on pigment indices) indicated variation in the percentage contribution of phytoplankton functional groups (Micro, Nano and Pico). Though the overall community structure was dominated by nanoplankton, as exhibited by pigment indices and CHEMTAX analysis, drastic shifts in the community were observed at 120. m depth at six hourly intervals. The oscillation between Flagellates (nanoplankton) to prokaryotes (picoplankton) and then to diatoms (microplankton) at this depth in three consecutive observations coincided with the significant variations in phosphate and nitrate concentrations, along with increase in abundance of the grazer community (ciliates and heterotrophic dinoflagellates). From the present study, it is evident that the flagellate group is the ideal one to survive in such a complex regime. However, the observed small interval oscillation in the phytoplankton community could be a coupled effect of bottom-up (vertical advection that alters the nutrient flux), and top-down (increased abundance of microzooplankton) factors. © 2015. Source

Velloth S.,Center for Marine Living Resources and Ecology | Mupparthy R.S.,National Center for Medium Range Weather Forecasting | Raghavan B.R.,Mangalore University | Nayak S.,Earth System Science Organisation
International Journal of Remote Sensing | Year: 2014

Among the various remote-sensing options available today to map ecomorphological classes of corals, hyperspectral remote sensing is one of the best options by virtue of its spectral capabilities, while high spatial resolution is a necessary condition to resolve finer morphological features spatially. Given high-spatial resolution data of equal to or better than 30 m, the discrimination capability of end-members of multi-/hyperspectral satellite data is dependent on the efficacy of the correction for atmospheric effects and the intervening water column. In this study, a coupled approach to account for oceanic and atmospheric radiative contributions, called the Coupled Ocean Atmosphere Radiative Transfer (COART), was applied to Earth Observing 1 (EO-1) mission Hyperion image data acquired over the coral reefs of Agatti Island in the Lakshadweep Islands, Arabian Sea and Flat Island in the Andaman Islands, Bay of Bengal, India. The paper presents an open-source approach to correct and perform unsupervised classification of Hyperion imagery using a custom-built software toolkit called HyperCorals. The study finds that Hyperion has sufficient capabilities for discrimination of a few ecomorphological classes and can be improved further by using coupled radiative transfer models. Correcting for the intervening water column helps in classifying submerged features. The k-means classification offers a simpler classification method to classify an image of a subset with 42 selected spectral channels of Hyperion in the visible and near infrared (VNIR) region than the traditional Iterative Self-Organizing Data Analysis Technique (ISODATA). The classification results using the cosine distance metric over 42 selected spectral channels of Hyperion in the VNIR region offer the potential to differentiate between various ecomorphological zones. The study also presents results from sensitivity analysis experiments and discusses the relative importance of three parameters: water column depth, bottom albedo, and chlorophyll concentration on the overall correction and classification of the imagery. © 2014 Taylor & Francis. Source

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