Diversity of intertidal macrobenthic fauna around Ratnagiri and Sindhudurg districts of Maharashtra, west coast of India

Diversity of intertidal macrobenthic community and environmental parameters namely temperature, salinity, pH and DO were assessed near the proposed nuclear power plant site Jaitapur from 2012 to 2014. Analysis of macrobenthic samples revealed the presence of 54 species belonging to 19 different groups. Highest diversity (14 groups) was observed during the post-monsoon (2014) season. At sandy and rocky shores, polychaetes were dominant followed by crustaceans like amphipod, isopod, penaeid shrimps and decapod larvae. Among all inshore stations, diversity was found to be maximum at Ganeshgule (N SW30 kms). Shannon-Weiner diversity index (2.259) and Margalef’s species richness index (2.502) indicated rich diversity at rocky habitats (N SW30 kms). The present study suggests the stable environmental parameters around the Jaitapur Nuclear Power Plant (NPP) sites and is responsible for the rich benthic community. The outcome of the present study may be useful as baseline information on macrobenthos around the proposed Jaitapur NPP site

Study on biology of Thryssa dussumieri (Valenciennes, 1848) from the coast of Ratnagiri, Maharashtra, India

The Dussumier’s thryssa, Thryssa dussumieri is one of the important component of by-catch of trawl and mini purse seine landings at Ratnagiri. The length-weight relationship indicated the isometric growth in T. dussumieri with generalized equation W = 0.0066 L 3.1077. The month-wise relative condition factor showed two peaks coinciding with peak spawning season. All morphometric lengths showed varying degree of correlation with total length. The qualitative and quantitative analysis of food revealed Thryssa dussumieri to be a carnivore, feeding mainly on mysids, copepods, diatoms and juvenile shrimps.The highest GSI value, for females, was observed during March, October, December and January. The male:female ratio was found to be 1:1.4. T. dussumieri has got a prolonged spawning season extending from September to April. The absolute fecundity ranged from 3367 to 14130 eggs with an average of 7420 eggs. Length at sexual maturity has been estimated to be 12.8 cm

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Not AvailableThe average phytoplankton density was observed to be highest during post-monsoon at inshore as well as offshore stations. Overall phytoplankton was comprised of Bacillariophyceae (81.4%), Dinophyceae (12%), Chrysophyceae (3%), Cyanophyceae (1.8%), Desmophyceae (2.9%) and Chlorophyceae (3.9%). A total of 86 species of phytoplankton belonging to 56 genera and 6 classes were recorded from offshore and inshore stations. A massive bloom of cyanobacteria Trichodesmium erythraeum was also sighted during the winter season. Dinoflagellates showed a peak during monsoon at inshore stations. Maximum values of diversity indices were recorded during winter at offshore and during pre-monsoon at inshore stations.Not Availabl

Diversity of intertidal macrobenthic fauna around Ratnagiri and Sindhudurg districts of Maharashtra, west coast of India

56-66Diversity of intertidal macrobenthic community and environmental parameters namely temperature, salinity, pH and DO were assessed near the proposed nuclear power plant site Jaitapur from 2012 to 2014. Analysis of macrobenthic samples revealed the presence of 54 species belonging to 19 different groups. Highest diversity (14 groups) was observed during the post-monsoon (2014) season. At sandy and rocky shores, polychaetes were dominant followed by crustaceans like amphipod, isopod, penaeid shrimps and decapod larvae. Among all inshore stations, diversity was found to be maximum at Ganeshgule (N SW30 kms). Shannon-Weiner diversity index (2.259) and Margalef’s species richness index (2.502) indicated rich diversity at rocky habitats (N SW30 kms). The present study suggests the stable environmental parameters around the Jaitapur Nuclear Power Plant (NPP) sites and is responsible for the rich benthic community. The outcome of the present study may be useful as baseline information on macrobenthos around the proposed Jaitapur NPP site

Reproductive biology and fishery of the white sardine, <em>Escualosa thoracata</em> (Valenciennes, 1847) from the Ratnagiri coast, Maharashtra

2485-2491In the present study of this fish, it has indicated prolonged spawning season from October to April with peak spawning from November to February along the coast of Ratnagiri, Maharashtra. Highest GSI value for both sexes were observed during November (9.1487 for males and 5.4335 for females) and lowest during June (1.2772 for males and 0.8855 for females). The highest value of K was found in February for both sexes, male (2.06) and (1.86) in females. Overall male: female ratio was 1: 1.19 indicating slight dominance of females. The ova diameter for this species ranged from 0.02 to 0.64 mm, absolute fecundity ranged from 6156 to 9924 ova with an average of 7674 ova. Size at first maturity for females has been estimated to be 79 mm

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Not AvailableThe present work deals with assessment of baseline radionuclide concentration in marine organisms around selected coasts of Maharashtra, India. This baseline study highlights concentrations of natural and fallout radionuclides in finfish and shellfish species found in the surrounding seawater. Water and fish samples were collected, processed, and analyzed for 238U, 226Ra, 228Ra, 232Th, 40K, and 137Cs by high-resolution gamma spectrometry. 238U, 226Ra, 228Ra, 232Th, 40K, and 137Cs concentrations were found to be in the range of ≤1.5, ≤2.0, ≤0.4, ≤1.5, ≤8.0 to 258, and ≤0.2 Bq/kg, respectively. The seasonal study revealed the maximum concentration in premonsoon season. Activity concentrations were higher in pelagic fish than those in demersal fish. A higher concentration factor was reported in shellfish than in finfish.Not Availabl