Peer Reviewed Journal Articles (National) (FT)

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Browsing Peer Reviewed Journal Articles (National) (FT) by Author "Ashraf, P.M."

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    Fishing hooks: a review
    (Society of Fisheries Technologists(India),Cochin, 2007) Thomas, S.N.; Edappazham, G.; Meenakumari, B.; Ashraf, P.M.
    Fishing hooks stand out among the simplest and the oldest of such devices. They are not well studied, and the available studies are out dated dur to emergence of new models materials and technologies. Methods of numbering of hooks are not standardized. This review dwells into their history and evolution, terminology, properties, classification, numbering, testing procedure and hooking efficiency. The study points to the need for a comparative study of hooks in terms of their relative properties and also as a conservation tool for sustainable development of recreational fishing.
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    In situ time series estimation of downwelling diffuse attenuation coefficient at southern Bay of Bengal
    (2013) Ashraf, P.M.; Shaju, S.S.; Gayathri, D.; Minu, P.; Meenakumari, B.
    The present study is aimed to determine the bio-optical characteristics of oceanic waters during South west monsoon in Bay of Bengal using hyperspectral radiometer. The variability of diffuse attenuation coefficient, Kd(1), with chlorophyll a showed a good relation at shorter wavelengths, indicating the effect of phytoplankton on Kd(1). The determination coefficient, R2 at 412, 443, 490 and 555 nm were greater than 0.931. A good linear relation between Kd(490) and Kd(1) was observed at shorter wavelengths. These relationships of Kd(1) provides a platform to study the underwater light field during Southwest monsoon in Bay of Bengal
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    Measurements of bio-optical parameters of southern ocean
    (National Centre for Antarctic & Ocean Research(Ministry of Earth Sciences), Goa, 2011) Shaju, S.S.; Minu, P.; Ashraf, P.M.; Meenakumari, B.
    Chlorophyll a concentrations (chl a) and the absorption coefficients of total particulate matter [ap(k)], phytoplankton [aph(A.)], detritus [ad(A.)], and colored dissolved organic matter: CDOM [aCDOM(X)] were measured in seawater samples collected in the Southern Ocean during the end of the summer of 2011. The concentration of the surface chlorophyll a varied from 0.025 to 0.400 mg m-' in the Southern Ocean during the sampling period. Indeed no correlation exists between absorption coefficient of phytoplankton and the main components of the water: total suspended matter, non-algal particles, salinity and CDOM absorption. This suggests that none of these variables alone can explain the scattering of the data. The relative contribution of CDOM, phytoplankton and non algal particles lie between 0.4 and 0.8, 0.2 and 0.6, and 0.1 and 0.4, respectively. So these inputs can be used to develop a comprehensive algorithm for the remote sensing reflectance and retrieval of optically active substances of the Southern Ocean.
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    Variation in polycyclic aromatic hydrocarbons in sediments of shrimp farms
    (CMFRI, 2003) Ashraf, P.M.; Radhakrishnan, A.G.; Gopalakrishna, A.G.G.
    Studies were conducted to find the variations of polycyclic aromatic hydrocarbons (PAH) in sediments of shrimp farms. Evaluation of their concentrations in different cropping seasons were studied in scientifically cultured ponds in comparison with that in a natural pond. The total PAH concentration was found to be higher in the scientific system in all cropping seasons. The levels of individual low molecular weight PAHs, i.e. from naphthalene to phenanthrene showed greater values during the juvenile stages that gradually got reduced at the harvest stage. Benzo[a]anthracene was the prominent component among the high molecular weight PAHs which also showed a maximum value during the juvenile stages of cropping. A slight increase in its value was observed in the harvest stage than late juvenile stages in scientific pond, which may probably be due to the addition of excess nutrients. Benzo[b]fluranthene was nondetectable in natural system, while it showed its presence in scientific system. Correlation data revealed that there is a strong positive correlation between organic matter and the levels of total PAHs, whereas negative correlation with clay which implies the minimum capacity of adsorption of PAH by clays.