Integrative Taxonomy of Tetraodontiform Fishes (Tetraodontiformes: Percomorpha) from Southwest Coast of India

Dominance of coastal upwelling over Mud Bank in shaping the mesozooplankton along the southwest coast of India during the Southwest Monsoon

While in recent years much attention has been focused on tsunamis in the Indian Ocean, generated near Indonesia, equally destructive tsunamis also could occur in the western part of the North Indian Ocean. Specifically, the last major tsunami in the Arabian Sea occurred in November 1945 due to an earthquake that originated in the Makran region. The Tunami N2 model was used to simulate numerically the tsunami propagation, run-up, and inundation on the southwest coast of India and selected locations in the Lakshadweep islands in the Arabian Sea. The simulations show that the run-up due to the 1945 Makran tsunami along the southwest coast of India and Lakshadweep islands was considerably less than that of the 2004 Sumatra tsunami.

Discriminating the biophysical impacts of coastal upwelling and mud banks along the southwest coast of India

ABSTRACTThis study investigates the timescale variability of key atmospheric and oceanic variables in the Arabian Sea (AS) using 45 years (1979–2023) of data. Analyzing sea surface temperature (SST), wind components, precipitation, significant wave height, and peak wave period, notable regional and seasonal variations are identified. The northern AS experiences the highest surface warming at a rate of 0.15°C per decade. The westerlies have strengthened in the southwestern AS, while the northern AS displays a weakening trend. Along the northwest coast of India, the northerlies have intensified, but along the southwest coast of India, they have weakened. Precipitation trends have significant increases only along the southwest and northwest coasts of India. The significant wave height has increased across much of the AS, with a pronounced rise observed near the Somali coast (about 0.2 cm per year), and the peak period in the eastern AS has decreased, indicating a decline in long‐period swells from the south. Even though this basin is strongly influenced by seasonal signals, the interannual variations in wave height anomalies are particularly significant in the central AS. Seasonal analysis reveals that the wave height in the central AS has a decreasing trend in June and August, despite being the peak monsoon months. This decrease corresponds with a similar decreasing trend in SST and westerlies, as well as an increase in the peak wave period. The study further explores the influence of dominant climate modes, such as the Indian Ocean Dipole (IOD) and El Niño‐Southern Oscillation (ENSO), on the AS climate. Even though the phase agreement between IOD and ENSO is relatively good (r = 0.67) during the study period, the years 1997 and 2023 have notable differences in the meridional wind patterns, which in turn influence the significant wave height. These findings emphasise the need for adaptive strategies to address the impacts of climate variability and long‐term trends on the marine environment of the AS.

Radiological dose and associated risk due to 210Po in commercial inter-tidal bivalves of southwest (Arabian Sea) coast of India

The nature of distribution, mode of attachment, incidence and intensity of infestation and the nature of damage by two host specific anthosomatid copepod parasites,Lemanthropus gibbosus Pillai andL. koenigii Stp. and Lutk. infesting fishesSaurida tumbil (Bloch) andParastromateus niger (Bloch) respectively, along the South-west coast of India are described. The results show that both these parasites are of serious concern to their hosts causing irreparable damage to the gills both by way of their mode of attachment and feeding activity. The blood circulation of the gills is severely curtailed and the infested gill filaments are completely put out of function.

The distribution of the parasites on the host, their mode of attachment to the host tissue, and the incidence and intensity of infestation of 17 species of copepods belonging to eight families and of four species of isopods belonging to the family Cymothoidae infesting 12 species of marine fishes along the South-west (Trivandrum) coast of India are described. The parasites show host specificity and they are highly selective as to the of attachment on the host. Incidence and intensity of infestation of the majority of the parasites examined are higher in the female fish than in the male.

Shoreline management plan for a protected but eroding coast along the southwest coast of India

A study of temporal variations of 7Be and 210Pb concentrations and their correlations with rainfall and other parameters in the South West Coast of India

An attempt has been made to develop a holistic understanding of upwelling and downwelling along the south-west coast of India. The main objective was to elucidate the roles of different forcings involved in the vertical motion along this coast. The south-west coast of India was characterized by upwelling during the south-west monsoon (May to September) and by downwelling during the north-east monsoon and winter (November to February). The average vertical velocity calculated along the south-west coast from the vertical shift of the 26 °C isotherm is 0.57 m/day during upwelling and 0.698 m/day during downwelling. It was concluded that upwelling along the south-west coast of India is driven by offshore Ekman transport due to the alongshore wind, Ekman pumping, horizontal divergence of currents and by the propagation of coastally trapped waves. Whereas downwelling along the coast is driven only by convergence of currents and the propagation of coastally trapped Kelvin waves. Along the west coast of India, the downwelling-favorable Kelvin waves come from the equator and upwelling-favorable waves come from the Gulf of Mannar region.

The present study identified the various zones vulnerable to urban flood in Cochin City, one of the biggest metro cities on the southwest coast of peninsular India. The analysis and assessment of vulnerability was done through the application of multi-criteria evaluation approach in a geographical information system environment with inputs from remotely sensed images. Other input data sources include SRTM DEM, census details, city maps and field study. Flood vulnerability mapping in the study area is fundamental in flood risk management. Among the three vulnerability zones, the very high and high vulnerable zones together constituted 8.6 % of the total area of the city. The major factors contributed are the blockage of drainage channels and the proximity to coastal waters where there is influence of tides.

Changes in the dynamical, thermodynamical and hydrometeor characteristics prior to extreme rainfall events along the southwest coast of India in recent decades

Meteorological aspects of mud bank formation along south west coast of India

Groundwater Situation at Southwest Coast of India –A Field Study, Overview, Opportunities and Challenges

Vinod, K.; Asokan, P.K.; Zacharia, P.U.; Ansar, C.P.; Vijayan, G.; Anasukoya, A.; Kunhi Koya, V.A., and Nikhiljith, M.K., 2019. Assessment of biomass and carbon stocks in mangroves of Thalassery estuarine wetland of Kerala, south-west coast of India. In: Jithendran, K.P.; Saraswathy, R.; Balasubramanian, C.P.; Kumaraguru Vasagam, K.P.; Jayasankar, V.; Raghavan, R.; Alavandi, S.V., and Vijayan, K.K. (eds.), BRAQCON 2019: World Brackishwater Aquaculture Conference. Journal of Coastal Research, Special Issue No. 86, pp. 209-217. Coconut Creek (Florida), ISSN 0749-0208.The mangrove ecosystems render many goods and services ranging from coastal protection to climate regulation. These ecosystems are also reservoirs of carbon stocks, due to their ability to sequester and store carbon in their biomass and the underlying sediment, and therefore significant in view of the climate change mitigation. The present study attempted to assess the biomass and carbon stock of mangroves of Thalassery estuarine wetland of Kerala, south-west coast of India. We assessed the carbon stocks of three carbon pools viz., above-ground, below-ground (root) and sediment. A total of eight species of mangroves were recorded from the Thalassery estuarine wetland, and of these, Avicennia officinalis was the dominant species with an average tree density of 729.37 individuals ha-1 and contributed most (45.05±23.79 t ha-1) to the total carbon. The overall mean above-ground biomass was 189.26±97.80 t ha-1, while the overall mean root biomass was 83.06±40.48 t ha-1. The estimated mean above-ground carbon was 94.63±48.90 t C ha-1, while the mean carbon stock in root and sediment were 41.53±20.24 t C ha-1 and 17.48±7.30 t C ha-1, respectively. In the present study, the estimates of mean combined C-stocks in mangrove and sediment showed that the mangroves of Thalassery estuarine wetland stored 153.64 t C ha-1 which was equivalent to 563.86 t CO2 ha-1. The mangroves of Thalassery wetland cover an area of approximately 5.8 ha and thus it can be assumed that this wetland has the potential to sequester and store 891.11 t C, equivalent to an estimated amount of 3270.37 t CO2. The study reinforces the importance of mangrove forests as useful carbon sinks and the need for protection of these critical habitats in the light of climate change mitigation.