Vulnerability of nesting ground of Olive ridley turtle to severe cyclonic storm Fani: A case study from Rushikulya rookery, East coast of India

摘要

Rushikulya rookery on India's east coast is one of the largest mass nesting grounds for Olive ridley sea turtles. This annual mass nesting event (arribada) is driven by sensitively interwound geo-ecological cues, which often gets disrupted by various anthropogenic impacts and extreme atmospheric events such as tropical cyclones. For the very first time, we investigated the effect of a highly untimely, category five cyclone Fani (made landfall on 03 May 2019, summer as opposed to usual landfall time autumn) on Rushikulya rookery and attempted to correlate mass nesting behaviour of Olive ridley turtle using remote sensing and GIS technology. Approximately 94 of the shoreline along the Rushikulya rookery receded 100 m inward aftermath of the cyclone Fani (2019) that resulted in 'no mass nesting' in that year. The most prominent feature was the fragmentation of the spit that seems to be a critical habitat and protective structure for successful mass nesting. The next year (2020), saw a highly successful mass nesting due to the spit's natural re-construction and possibly cyclone-driven nutrient enrichment. Since very severe but untimely cyclones are predicted to increase due to climate change, this study will act as the first baseline information on the likely impact of such extreme weather events on migratory marine turtles in India.