Report on Death of Dwarf Sperm Whale, Kogia sima (Order: Cetacea: Family: Kogiidae) in Vedalai Shore of Mandapam, Gulf of Mannar

Aims: Present study aims to highlight an accidental death of a male Dwarf Sperm Whale scientifically known as Kogia sima which found to be as Least Concern (LC) as per IUCN Red List data. Kogia sima represents important higher trophics of marine ecosystem which faced the several threats and conservation need in Gulf of Mannar, India. Study Design: The study undertaken during extensive coral reef monitoring survey was carried out in Gulf of Mannar under the CRAM Project of National Centre for Coastal Research (NCCR). The present report emphasize the Morphometric observation of the dead Kogia sima and try to find out possible cause of death by examining in situ investigation. Place and Duration of Study: The field study was taken in Vedalai Sea shore (N09�.626�, E79�.977�) under the Mandapam Union of Ramnathapuram District of Tamil Nadu. The male whale specimen was found on 5th May, 2019 lying dead on the sandy seashore. Methodology: Animal was photographed and morphological attributes were measured to identify the specimen. Several injuries have been highlighted in the paper which helps in investigating the cause of death. Results: The Dwarf Sperm Whale was infant and has mild damage on the mouth parts including scuff off skin from the body and severe blood clotting at major part of the right side near to pectoral fin. Death of this infant is not clear but it is assumed that the male infant has lost from his parents and came to the inshore area of Mandapam where it gets stuck with running boat or boulder rocks as this immature whale limits its diving capabilities. The necessary morphological characters and measures have been listed in Table 1. Conclusion: This unfortunate death clearly indicated that acute information on ecological behavior of Dwarf Sperm Whale is still under data collection stage in India and that previous conservation efforts in country must be reviewed in terms of role of local authorities, live stranded cetaceans and hunting or incidental killing which in future can build a road map for effective action plans to save this marine mammal.

Rhizobacterial population density and nitrogen fixation in seagrass community of Gulf of Mannar, India.

Seagrass rhizosphere generally supports high bacterial population density which plays a major role in determining the nutrient cycles of the sea. Higher densities of total heterotrophic bacteria (26.3 ?06 CFU g-1), nitrogen fixing (27.3 ?03 CFUg-1), ammonifying (44.66 X 106 MPN g-1) and nitrifying bacteria (42.33 X 106 MPN g-1 ) have been registered in the seagrass areas than the non seagrass area. In particular, all these rhizosphere microbial population was higher in Thalassia hemprichii. The rates of nitrogen fixation was recorded in the different species of seagrasses such as Enhalus acoroides (1.166 n mol g-1d-1), Halophila ovalis (0.166 n mol g-1d-1), Thalassia hemprichii (18.5 n mol g-1d-1), Cymodocea serrulata (10.5 n mol g-1d-1), Halodule uninervis (5.375 n mol g-1d-1) and Syringodium isoetifolium (0.666 n mol g-1d-1) using gas chromatography. The average nitrogen fixation by the seagrasses of Gulf of Mannar alone was estimated to be 7640.58 n mol m-2 d-1 and the contributions from the rhizosphere microbes will increase the quantity to many fold.

Fouling communities on ship wreck site in the Gulf of Mannar, India.

The Gulf of Mannar is one of the world’s richest marine biospheres and occupies an area of 10,500 sq.km. Twenty one coral reef islands and small patchy reefs are present between Lat. 800 47’N and Long. 780 12’ E to Lat. 900 15’ N and Long. 790 14’ E. from Pamban to Thoothukudi as an arc. These islands possess a very interesting heterogeneous group of fauna and flora. The study was conducted on a twenty year old ship wreck in the Gulf of Mannar, India. During low tides, remnants of the ship are exposed to about 1.5 meters above the water surface. The entire ship wreck is regarded as an artificial reef that harbors corals, fishes and other fauna. Artificial reefs are beneficial in reef conservation and rehabilitation efforts. Successions of artificial reef communities were preliminarily studied using the Line and Belt transect method to assess the composition of benthic organisms like soft corals (25.6 %) and live corals (23.1 %). The abundance of several common reef fishes is also reported.

Seasonal variations of trace metal accumulation on coral reef in Gulf of Mannar, India.

Investication of trace metal occumulation on coral and reef environment (sediment and water) of the Gulf of Mannar biosphere reserve was studied during July 2007 to June 2008. The samples were collected for analyzing from Thoothukudi and Vembar group of Islands, Gulf of Mannar. The concentration of trace metal in the water are in the order of Fe > Pb > Zn > As > Mn > Cd > Cu and in sediment in the order of Fe > Mn > Pb > Zn > Cu >Cd and in coral rubbles in the order of Fe > Mn > Pb > Zn > Cu > Cd. In the waters the iron ranks first and copper ranks last; in the sediment iron ranks first in concentration and cadmium ranks the last. In corals the iron ranks first and cadmium ranks the last in concentration and during the entire study periods. SPSS two tailed Correlation coefficients between the months and the temporal variablilities of heavy metals were assessed using the monthly data for each component in all stations and analysis of variances (f values) for the water, sediment and coral rubbles between the stations and month during the study period. Conclude that the values recorded at Thoothukdi group of islands were little higher than the Vembar group of islands, and it might be due to discharges pumped from the industrial belt of Thoothukudi, domestic sewages from Thoothukudi town, harbour activities and thermal power plant operation along the southern side of the Gulf of Mannar.