NOPR Collection:

Heavy mineral contents and provenance of Late Quaternary sediments of southern Kerala, Southwest India

2013-12-22T16:45:03Z

Title: Heavy mineral contents and provenance of Late Quaternary sediments of southern Kerala, Southwest India Authors: Anooja, S; Padmalal, D; Maya, K; Mohan, S Vishnu; Baburaj, B Abstract: Present paper deals with provenance and depositional history of the Late Quaternary sediments including heavy mineral placers in the coastal lands of Kollam district, SW India. Kollam coast is endowed with estuaries, old coastal plains with ridge-runnel systems and barrier beaches. Mineralogical analysis reveals that sediments in the estuarine basins that are seen entrenched over the Neogene sedimentary deposits were derived from dual sources. Heavy mineral residues of the upper estuarine zones are generally garnet bearing and are of alluvial origin. At the same time, sediments in the lower estuary are garnet-free and are derived from the nearby littoral zones during the tidal processes. Heavy mineralogical data together with statistical analysis discloses that the garnet and pyribole-free heavy mineral suite in the beaches and nearby coastal plains of the Kollam coast are primarily derived from denudation of the Neogene sedimentary deposits in the coastal lands. They are evolved during the rising phases of the sea level in the Late Quaternary period. Page(s): 749-757

Purification and activity of amylases of Marine Halobacillus sp amylus HM454199

2013-12-16T16:47:38Z

Title: Purification and activity of amylases of Marine Halobacillus sp amylus HM454199 Authors: Ashwini, K; Karthik, L; Kumar, Gaurav; Rao, K V Bhaskara Abstract: Present study was focused on purification and activity of amylases of marine eubacteria. Among 23 bacterial isolates from Nicobar Islands, Halobacillus sp amylus was selected and further examined. Enzyme activity was evaluated at different temperatures (25, 30, 35, 40 and 45ºC), at varying pH (6.0, 6.5, 7.0, 7.5 and 8.0) and by using various carbon sources (starch, glucose, sucrose, fructose, xylose and lactose). Different organic nitrogen sources (yeast extract, meat extract, beef extract, nutrient broth, urea and casein) and various concentration of NaCl were also used to evaluate enzyme activity. Maximum enzyme activity was recorded at 40°C, pH 8.0 and 1.0% of substrate concentration. Halobacillus sp amylus gave 12000 U of amylase per litre of culture broth, 3 fold higher than before optimization in submerged fermentation. Thus, these observations conclude that the enzyme obtained was relatively heat sensitive and moderately alkalophilic amylase which can be developed for extensive industrial applications. Page(s): 781-785

Reproductive biology and population characteristics of Sardinella gibbosa and Sardinella fimbriata from north west Bay of Bengal

2013-12-18T16:49:40Z

Title: Reproductive biology and population characteristics of Sardinella gibbosa and Sardinella fimbriata from north west Bay of Bengal Authors: Ghosh, S; Rao, M V Hanumantha; Sumithrudu, S; Rohit, P; Maheswarudu, G Abstract: Reproductive biology and population characteristics of Sardinella gibbosa and Sardinella fimbriata landed by gill netters from north west Bay of Bengal was studied during 2005 – 2010. Average annual catch was 21080 t, in which the contribution of S. gibbosa was 12790 t and the contribution of S. fimbriata was 8290 t. SST, rainfall and chlorophyll a were found to affect the annual catch of lesser sardines. Length weight relation showed differential growth between adults and indeterminates for both the species. Overall sex ratio varied between 1:1.28 to 1:1.33 for S. gibbosa and between 1:1.02 to 1:1.025 for S. fimbriata with length at first maturity of 13.03 cm for S. gibbosa and 13.27 cm for S. fimbriata. Peak spawning season was February – April for S. gibbosa and May - July for S. fimbriata. Total fecundity ranged between 12786 ova to 68377 ova for S. gibbosa and between 11066 ova to 60981 ova for S. fimbriata. Mature ovaries in lesser sardines contained both immature and mature ova. Von Bertalanffy growth equation was L_t = 20.7 [1 – e ^- ^{0.96
(t + 0.018)}] for S. gibbosa and L_t = 20.7 [1 – e ^- ^{0.85 (t + 0.023)}] for S. fimbriata. Natural mortality, fishing mortality, total mortality and exploitation rate were 1.90, 3.56, 5.46 and 0.65 for S. gibbosa and 1.75, 2.57, 4.32 and 0.59 for S. fimbriata, respectively. A higher value of E than E_0.5for both Sardinella gibbosa and Sardinella fimbriata and a lower value of Maximum Sustainable Yield than annual average catch indicate intensive fishing of lesser sardines along north west Bay of Bengal. Page(s): 758-769

A comparative study of neural-network & fuzzy time series forecasting techniques - Case study: Marine fish production forecasting

2013-12-25T16:47:17Z

Title: A comparative study of neural-network & fuzzy time series forecasting techniques - Case study: Marine fish production forecasting Authors: Yadav, V K; Krishnan, M; Biradar, R S; Kumar, N R; Bharti, V S Abstract: Various forecasting methods have been developed on the basis of fuzzy time series data, but accuracy has been matter of concern in these forecasts. Historical data of marine fish production of India have been taken to implement the model; as such time series data obtained through sample survey are likely to be imprecise. Fuzzy sets theory of¹ and fuzzy time series models introduced by^2-5, were applied in this study. The forecast to marine fish production have also been obtained by developing an Artificial Neural Network (ANN) model using Back propagation algorithm. It is aimed to find the marine fish production forecast for a lead year by using different fuzzy time series models and back propagation algorithm for the forecast. Forecasted marine fish production, obtained through these techniques, has been compared and their performance has been examined. Present infers that ANN produces more accurate results in comparison of fuzzy time series methods. Page(s): 707-716