NOPR Collection:

Buoy data assimilation to improve wave height assessment in Bay of Bengal during monsoon seasons

2017-05-29T10:42:36Z

Title: Buoy data assimilation to improve wave height assessment in Bay of Bengal during monsoon seasons Authors: Kalyani, M; Latha, G; Sannasiraj, S A; Venkatesan, R Abstract: Significant wave height assessment in Bay of Bengal derived from third generation Wave Model (WAM cycle 4) has been improved by assimilating with continuous three hourly data from five moored buoys of National Institute of Ocean Technology using optimum interpolation technique. Covariance based weight function (gain) used in the study captures the model physics behind wind-wave process while distributing the errors at any buoy location. Gain composition at different buoy locations, due to assimilation of each buoy has been reported for both southwest (July) and northeast (November) monsoons, for year 2004. Qualitative and quantitative improvement in significant wave height due to buoy data assimilation during these two seasons are presented with reference to changing wind and wave characteristics. The order of improvement is found to be proportional to the magnitude of deviations found with respect to the measurements. Considerable model area has been influenced by assimilation. Page(s): 1083-1090

Seasonal changes of macroalgal composition, biomass and assemblage diversity in the rocky intertidals of Zhifu Tombolo, China

2017-05-29T10:39:43Z

Title: Seasonal changes of macroalgal composition, biomass and assemblage diversity in the rocky intertidals of Zhifu Tombolo, China Authors: Liu, Hongmei; Liu, Xuemei; Jiang, Aili Abstract: In all seasons, red algae formed the component with the highest species number and biomass, brown algae ranked the second and green algae the last. The seasonal changes in total algal biomass in the assemblage were sequenced as following: August (228.64 g/m²) > October (161.63 g/m²) > June (207.29 g/m²) > April (117.19 g/m²) > December (77.96 g/m²) > February (41.29 g/m²). An outstanding seasonal variation of both macroalgal composition and dominance in the intertidal assemblage was observed during the survey. Species richness and diversity in the intertidal assemblage showed a seasonal rhythm in which the highest levels in Margalef’s species richness index (R) and Shannon-Wiener’s species diversity index (H’) were found in April (R 6.23) and June (H’ 3.08) respectively. In terms of the function of dominant species based on biomass the surveyed assemblages could be grouped into three macroalgal assemblage aspects: “Geldium - dominating spring-association”, “Sargassum - dominating summer-association” and “Ulva - dominating autumn- winter - association”. Page(s): 1091-1097

Comparative taxonomic evaluation of Thais species (Order: Gastropoda; Family: Muricidae) of Mollusca from Maharashtra coast of India

2017-05-29T10:34:38Z

Title: Comparative taxonomic evaluation of Thais species (Order: Gastropoda; Family: Muricidae) of Mollusca from Maharashtra coast of India Authors: Kumar, Ravi; Jaiswar, A.K.; Jahageerdar, S.; Chakraborty, S.K.; Kumar, A. Pavan; Prasad, Laxmi Abstract: Based on shell morphology alone, it was difficult to differentiate the species belonging to genus Thais because of large amount of plasticity, observed in the shell characters. The colour of the shells was poorly defined as species identifying character in Thais species. The morphometric and meristic characters of the shell along with radular characters can solve the taxonomic ambiguities in Thais species (Thais lacera; T. blanfordi; T. tissoti; T. rudolphi; T. bufo and T. subnodulosa). The radular morphology was found to be different in each species except in T. rudolphi and T. blanfordi and hence these two species were differentiated based on radular morphology where the first denticle on outer base of the lateral cusp was smaller than other five denticles in T. rudolphi but in T. blanfordi, all were same in size. A deep ‘V’ shaped notch was present between inner denticle base of lateral cusp and central cusp in T. blanfordi, which was found to be a species specific character. Page(s): 1098-1104

New record of two free-living marine nematode species, Sphaerolaimus balticus and Sphaerolaimus islandicus (Nematoda: Sphaerolaimaidae) from Sipphighat mangrove region, South Andaman

2017-05-29T10:29:36Z

Title: New record of two free-living marine nematode species, Sphaerolaimus balticus and Sphaerolaimus islandicus (Nematoda: Sphaerolaimaidae) from Sipphighat mangrove region, South Andaman Authors: Prasath, D.; Balasubramaniam, J.; Marimuthu, P.; Jayaraj, K. A. Abstract: Occurrence of the marine nematode family Sphaerolaimidae is the first report in the mangrove vegetation of Andaman Islands. Samples have been collected from South Andaman Islands. Important taxonomic features of two newly reported species of genus Sphaerolaimus are described and illustrated. Page(s): 1105-1109