X-ray diffraction studies on Mycobacterium smegmatis DNA

This article does not have an abstract

Observations on the grazing phenomenon of the cultured seaweed, Gracilaria edulis by fish in Minicoy lagoon (Lakshadweep)

The seaweed Gracilaria edulis is a fast growing agarophyte and its distribution is confined to Tamil Nadu, Andaman-Nicobar islands, Lakshadweep group of islands and Chilka lake along the Indian Coast. In Lakshadweep, it has been reported growing abundantly in the islands of Agatti, Kavaratti, Kalpeni and Kadamath while in Minicoy it was totally absent till recently. In 1990 this seaweed was transported from Mandapam (Gulf of Mannar) and Kavaratti islands (Lakshadweep) to study the feasibility of its establishment and colonizing in the lagoon in Minicoy

Late Quaternary sea level and environmental changes from relic carbonate deposits of the Western margin of India

Relic carbonate deposits along the western margin of India occur as dolomite crusts, aragonite sands (pelletal/oolitic) and aragonite-cemented limestones, oyster shells, corals, encrusted coralline algal and foraminiferal-dominated nodules. The petrology and mineralogy of the deposits indicate that except for aragonite sands and foraminiferal nodules, the others were formed in shallow marine conditions and serve as sea level indicators. Radiocarbon dates were measured for 62 relic deposits covering the entire margin. The age of these deposits on the continental shelf off Cape Comorin and Mangalore, between 110 and 18 m depth, ranges between 12, 610 14C yr BP and 6,390 14C yr BP. On the northwestern margin of India, especially on the carbonate platform (between 64 and 100 m), the age ranges from 17,250 to 6,73014C yr BP. The relic deposits of the Gulf of Kachchh at depths between 35 and 25 m are dated at 12,550-9,63014C yr BP. The age vs. depth plot of the relic deposits further indicates that the Gulf of Kachchh was inundated much early, atleast by 15 ka, after the Last Glacial Maximum, and was subjected to uplift and subsidence during the Holocene. The carbonate platform subsided during the early Holocene. Some of the relic deposits between Cape Comorin and Mangalore plot on or, closely follow the glacio-eustatic sea level curve. Despite abundant siliciclastic flux discharged by the Narmada and Tapti during the early Holocene, the platform off these rivers is largely devoid of this flux and carbonate sedimentation continued until 6,700 14C yr BP. We suggest that the river-derived sediment flux diverted southwards under the influence of the SW monsoon current and, thereby, increased the turbidity on the shelf and slope southeast of the carbonate platform and facilitated the formation of deeper water foraminiferal nodules off Vengurla-Goa

Spurt in fish landings along north Tamil Nadu coast

In the sudden spurt of unusually heavy fish landings a movement of deep water fishes to the inshore areas were observed and of this unusual landings along the coast during this period are presented. The heavy fish landings were observed for 15 days in landing centres adjacent of Pondicherry whereas it for 2 days in Kovalam region and in Madras. A slight drop in surface water temperature with low oxygen concentration (1.10 to 1.37ml/L) and low temperature (26.2 to 27.2°C) during this period were examined. Analysis of plankton samples showed a a bloom of Chaetoceros sp.in this period

Chlorophyll a and pheo - pigment as indices of biological productivity in the inshore surface waters off Cochin

Estimations of surface chlorophyll a and pheo-pigment concentrations were made at two stations (10 and 20m) in the inshore waters off Cochin which are correlated with related environmental parameters. In 1987 the maximum chlorophyll a production in both the stations was during pre-monsoon (2.3 and 2.1 mg/m3) while in 1988 it was during post monsoon period (3.4 and 3.2 mg/m5). In general a considerable reduction in overall production was noticed in 1987 over 1988, particularly during both monsoon and post-monsoon periods. The total annual chlorophyll a production was found to be 38.4 mg/m3 in 1987 whereas in 1988 it was 62.2 mg/m5 adding stations I & II together. The total annual pheo-pigment production was estimated to be 37.2 mg/m3 for stations I and II put together in 1988, contributing about 62% of chlorophyll a. As regards the environmental parameters, nutrients, especially phosphate showed positive correlation and nitrite negative relation to chlorophyll production. Variations in the observed values during 1987and 1988 are attributed to the intensity of monsoon rain fall and the freshwater discharge from the river and lake system

Marine pollution - its effects on living resources with special reference to aquaculture

Due to large scale industrialisation and indiscriminate discharge of effluents with high BOD, toxic chemicals and particulate matter reach the aquatic environment, either directly or indirectly. Enrichment of the coastal waters through nutrients and minerals lead to immediate and long term effects on the biota and fishery resources causing severe eutrophication or mass mortality. Among a large variety of pollutants which reach the aquatic environment, the domestic sewage, agricultural pesticides, industrial wastes, oil and oil dispersants, radioactive wastes and the polluted water from the coconut retting zones causes deleterious effects in the inshore and fish fanning areas

A note on cetacean distribution in the Indian EEZ and contiguous seas during 2003-07

Relatively little is known about the distribution of cetaceans in Indian seas due to lack of systematic surveys. For collecting data on species distribution, 35 opportunistic surveys were conducted onboard FORV Sagar Sampada between October 2003 and February 2007 in the Indian EEZ and contiguous seas. In 5,254 hours of sighting effort, a total of 473 cetacean records were made with 5,865 individuals. The occurrence of 10 species from three cetacean families was confirmed. The Indo-Pacific bottlenose dolphin was the most frequently sighted species, whereas the spinner dolphin was dominant in terms of abundance. Long-beaked common dolphins, Indo-Pacific hump-backed dolphin and sperm whales were also recorded at frequent intervals. Cetaceans were found to have a wide geographical distribution in the Indian EEZ and contiguous seas. High abundance and species richness were recorded in the Southeastern Arabian Sea and southern Sri Lankan waters. From the information collected during the present study, the platform of opportunity has proved to be a useful means for cetacean surve

Hydrographic features off northeast coast and Andaman - Nicobar Islands in relation to demersal finfish resources

Temperature varied from 17.6 to 28.5°C, salinity values from 32.12 to 35.21 x 10"" and dissolved oxygen from 0.8 to 4.41 ml/1. No identifiable relationship could be established between these three parameters and the total fish abundance, probably because the catch was made up of many species having different requirements. Higher abundance of trawl catches was from January to May when bottom water temperature was relatively low. The highest level of abundance of 2764 kg/hr in February 1989 was recorded when the parameters were 26°C, 33.6 x 10" and 2.71 ml/1; and the lowest level of 43.2 kg/hr in July 1988 was when the parameters were 25.3°C, 34.48 x 10'^ and 1.6 ml/1

Indian Efforts on the Inventorization of Marine Mammal Species for their Conservation and Management

The present study is the first attempt to use molecular tools for identification of marine mammals in India. The objective was to develop a database of genetic sequences for future marine mammal research in addition to confirming the species identity of cetaceans and dugongs using a molecular approach. Partial sequencing of mitochondrial DNA loci was carried out in accidentally caught/stranded specimens of Spinner dolphin (Stenella longirostris), Pantropical spotted dolphin/bridled dolphin (Stenella attenuata), Bottlenose dolphin (Tursiops aduncus), Long-beaked common dolphin (Delphinus capensis), Indopacific humpbacked dolphin (Sousa chinensis), Risso’s dolphin (Grampus griseus), Finless porpoise (Neophocaena phocaenoides), Sperm whale (Physeter macrocephalus), Blue whale (Balaenoptera musculus), Bryde’s whale (Balaenoptera edeni) and Dugong (Dugong dugon). Molecular identification of species was done by phylogenetic reconstruction of the sequences using portals GenBank and DNA Surveillance. Apart from ratifying their morphological identification, the analysis was able to distinguish specimens that otherwise, could not have been identified using conventional approaches. Phylogenetic analysis of the Sousa-Stenella-Tursiops-Delphinus group indicated more or less robust monophyly for all species in this complex, except Delphinus capensis. A sister-group relationship for Sperm whales and Baleen whales was evident, that would place the former closer to the latter than to any other group of toothed whales