Scientists from ICAR-Central Marine Fisheries Research Institute (CMFRI) have reported a dramatic tenfold rise in whale strandings along India’s southwest coast over the past decade, highlighting the urgent need for region-specific conservation strategies in the face of climate change.
The study, covering data from 2004 to 2023, revealed that annual whale strandings surged from just 0.3% between 2003 and 2013 to 3% between 2014 and 2023. Researchers attributed this sharp increase to changes in ocean ecosystems, anthropogenic pressures, and environmental disturbances.
Kerala, Karnataka, and Goa emerged as key hotspots, together accounting for most of the recorded strandings. High vessel traffic, intensive fishing, environmental shifts, and shallow coastal shelves were identified as major contributing factors. The rise in public awareness, social media activity, and citizen reporting has also led to higher detection and reporting rates. The study flagged noise pollution, ship strikes, and habitat degradation as significant threats to these endangered marine mammals.
Among the species documented, Bryde’s whale was the most frequently stranded, with occasional reports of blue whales. Genetic analysis revealed two distinct forms of Bryde’s whales inhabiting Indian waters.
In 2023 alone, nine strandings were recorded, primarily between August and November, marking the highest number in recent years. The study found a positive correlation between whale strandings and chlorophyll-a concentration, an indicator of ocean productivity during the southwest monsoon. Nutrient upwelling during this period boosts plankton and fish populations, attracting whales closer to shore. However, rising sea surface temperatures (SST) and strong converging currents have been disrupting marine ecosystems and increasing stranding incidents.
The researchers stressed the importance of developing predictive models using satellite data such as chlorophyll levels, wind patterns, and SST to anticipate strandings and enable pre-emptive conservation action.
“Region-specific conservation strategies are required to address this marine biodiversity threat in one of the country’s richest oceanic zones,” said Dr. R. Ratheesh Kumar, lead author of the study published in Regional Studies in Marine Science and principal investigator of the national project on Marine Mammal Stock Assessments in India.
The study calls for establishing real-time alert systems, marine megafauna conservation networks, training programmes for fishers and officials, and strengthening citizen science platforms for better monitoring and response.
