01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-06-0226 |
| Title of Abstract | Satellite Seascapes, Signatures and Habitat Clues of Marine Mammal Distribution and Phytoplankton Assemblages in Indian waters |
| Authors | Monolisha S*, Ratheesh Kumar R*, Trevor Platt, Shubha Sathyendranath, Eldho Varghese, Prathibha Rohit, Grinson George |
| Organisation | ICAR-Central Marine Fisheries Research Institute, Ernakulam |
| Address | 563, ANNA STREET, Near karanai Puducherry Road, Urappakkam URAPPAKKAM, Tamil Nadu, India Pincode: 603210 E-mail: monasundar1426@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Cetacean distribution and habitat preferences in Indian waters remain poorly understood, particularly in relation to dynamic oceanographic and optical conditions. Recent increases in sightings and strandings along the southwest coast of India, especially during the southwest monsoon, raise concerns about how monsoon-driven upwelling, phytoplankton blooms, and fisheries dynamics influence cetacean movement. These seasonal processes alter ocean optical properties, creating dynamic and spatially distinct seascapes. This study uses normalized satellite Remote Sensing Reflectance (Rrs) across six wavelengths (412⿿670 nm) from 2021 to 2023 to derive optical seascapes. A Fuzzy C-Means classification identified five distinct optical classes, mapped seasonally. We propose a synoptic framework integrating these optical seascapes with cetacean sighting records to evaluate whether specific water types, shaped by processes such as upwelling, chlorophyll blooms, or sediment plumes, correlate with cetacean distribution, foraging, or migration. Preliminary results indicate recurrent cetacean activity along the southwest coast aligns with turbid-green Case-2 waters (Classes 3⿿5), characteristic of high productivity. These waters are linked with monsoon-driven upwelling, Noctiluca blooms, small pelagic fish aggregations, and whale migratory pathways in the Arabian Sea. Spatio-temporal analyses of reflectance spectra and chlorophyll-a support this, with localized blooms in October 2023 showing concentrations up to 15 mg/m³ and a distinct 560 nm signature. Additionally, Ekman transport-induced upwelling (June⿿September) followed by fall intermonsoon conditions (October⿿November) appears to influence coastal whale migrations. Our findings highlight the potential of optical classification to identify ecologically significant regions for marine mammals in Indian waters. Linking satellite-derived water colour data with marine megafauna ecology offers a novel, large-scale approach to inform conservation planning and support ecosystem-based management under a changing climate. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Seascapes, Optical properties, Clustering, Marine Mammals, Migration, Indian waters |
| For Awards | yes |
| Date Of Birth | 17-04-1989 |
| ECSN Registration Number | IIOE2-ECSN-0146 |