http://nopr.niscair.res.in/handle/123456789/1497 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/4171 Title: Full-depths zooplankton composition at two deep sites in the western and central Arabian Sea <br/> <br/>Authors: Fabian, Heiner; Koppelmann, Rolf; Weikert, Horst <br/> <br/>Abstract: <smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> The temporal distribution and faunistic composition of zooplankton was studied by means of fine stratified oblique tows with a 1 m² MOCNESS at one station in the western and central Arabian Sea, each. The 333 µm net samples covered the whole water column down to ca. 4000 m, commencing 50 m above bottom, during three monsoon periods: the fall intermonsoon in October 1995, the spring intermonsoon in April 1997 and the NE monsoon in February 1998. Copepods were most abundant at both stations, ostracods ranked next, followed by malacostraceans, and chaetognaths. Total numerical standing stocks varied at the western site between 35 500 and 93 100 no./m² and at the central site between 27 300 and 65 800 no./m². In the epipelagic zone (0-150 m), only calanoid copepods, chaetognaths and gelatinous zooplankton showed an in-phase coupling with the seasonal pattern of primary production, with lowest concentrations during the spring intermonsoon; for all other groups the coupling is not clear. In the mesopelagic zone (150-1050 m), characterized by a pronounced oxygen minimum zone (OMZ), distinct changes in the faunistic composition were found: In the core of the OMZ (O₂ below 0.15 mg/l), the relative abundance of calanoid copepods rose up to 95%, whereas non-calanoid copepods and chaetognaths nearly disappeared. The vertical distributions of selected copepod taxa are discussed in relation to the oxygen profiles. Below the core of the OMZ several groups showed a subsurface peak in abundance. In the bathypelagic zone, below 1050 m, 4-11% of the water column zooplankton standing stock was found. </smarttagtype> <br/> <br/>Page(s): 174-187 http://nopr.niscair.res.in/handle/123456789/1559 Title: Distribution of marine macro-algae at different salinity gradients in Chilika lake, east coast of India <br/> <br/>Authors: Rath, J.; Adhikary, S. P. <br/> <br/>Abstract: Biomass of macro-algal forms with their seasonal and sectoral distribution in the salinity gradient of Chilika lake was evaluated. Three macro-algae, Gracilaria verrucosa, Enteromorpha intestinalis and Chaetomorpha linum occured abundantly in the lake throughout the year. These organisms preferred moderate salinity of Southern and Central sectors and their biomass changed in response to the salinity levels during different seasons. Gracilaria verrucosa and E. intestinalis did not grow in the Northern sector where the salinity level was least in the lake. Maximum biomass was obtained in the winter followed by summer and rainy seasons. The total biomass of 26,963 tonnes dry weight in 7.63% of the total area surveyed showed richness of macro-algal resources in the lake. Of this, occurrence of 14,467 tonnes of the economically important alga Gracilaria verrucosa suggests its possible exploitation for agar production. <br/> <br/>Page(s): 237-241 http://nopr.niscair.res.in/handle/123456789/1558 Title: ENSO signature in the sea level along the coastline of the Indian subcontinent <br/> <br/>Authors: Srinivas, K.; Kumar, P.K. Dinesh; Revichandran, C. <br/> <br/>Abstract: Evidence for the signature of El Nino-Southern Oscillation (ENSO) phenomenon in the monthly mean sea level at 8 tide gauge stations on the west coast and 7 stations on the east coast of the Indian subcontinent is presented. The Southern Oscillation Index (SOI, indicator of the ENSO phenomenon) available continuously from 1933 onwards, was utilized to examine the relationship between sea level and ENSO. The relationship between sea level and SOI is direct, with the sea level decreasing during El Nino years and increasing during La Nina years. The signature of ENSO is particularly conspicuous in the sea level records on the east coast as compared to those on the west coast. Reduced rainfall over the Indian subcontinent and resultant river discharges, remote forcing by interannual zonal winds along the equator and reduced Indonesian Throughflow could be the probable factors explaining the low sea level along the coastline of the Indian subcontinent during ENSO events. The interannual sea level along the coastline of the Indian subcontinent shows more or less synchronous movement-the rise and fall is nearly simultaneous. At low frequency, spatial coherence of sea level is very large. <br/> <br/>Page(s): 225-236 http://nopr.niscair.res.in/handle/123456789/1557 Title: Statistical modelling of monthly mean sea level at coastal tide gauge stations along the Indian subcontinent <br/> <br/>Authors: Srinivas, K.; Das, V. Kesava; Kumar, P.K. Dinesh <br/> <br/>Abstract: This study investigates the suitability of statistical models for their predictive potential for the monthly mean sea level at different stations along the west and east coasts of the Indian subcontinent. Statistical modelling of the monthly mean sea level at 15 selected tide gauge stations (8 stations on the west and 7 stations on the east coast) along the coastline of the Indian subcontinent was attempted using autoregressive, sinusoidal and exponentially weighted moving average (EWMA) techniques. Statistics pertaining to the mean seasonal cycle as well as interannual variability are also presented. A strong domination of the annual cycle over the semi-annual cycle was seen at ten stations. The maximum seasonal sea level ranges were observed along the west coast at Bhavnagar (63 cm) and along the east coast at Sagar Island (48 cm). While the autoregressive and sinusoidal models were satisfactory, EWMA technique was found to be the best of all. Tuticorin on the east coast, and Mormugao on the west coast have shown minimum RMSEs for the corresponding coasts for all the three models, while Bhavnagar on west coast has shown very high RMSE values. The EWMA technique (which yields forecast with a lead time of only one month) gave the lowest root mean square errors relative to the verifying observations. <br/> <br/>Page(s): 212-224