Marine Mammal Deaths in Kerala Highlight Growing Threat of Plastic Pollution along India’s Coast

On July 4, 2026, local residents discovered an Indian Ocean humpback dolphin and an Indo-Pacific finless porpoise dead at separate locations on Kozhikode beach in Kerala. Alerted by the public, officials recovered the carcasses for post-mortem examination.

The necropsy of the roughly 200-kg dolphin, classified as endangered on the IUCN Red List, revealed a nearly 2 kg plastic fishing net tightly lodged in its oesophagus, disrupting normal feeding and leading to its death. Dr. K.M. Manojlal, chief veterinary officer at the District Veterinary Centre, Kozhikode, who conducted the necropsy, said: “It might have accidentally ingested the net while feeding on marine prey, but was unable to regurgitate it. We believe the net was originally in the stomach. As fermentation produced gas, the plastic twisted into a ball under pressure and was forced into the oesophagus.”

The post-mortem of the approximately 80-kg Indo-Pacific finless porpoise suggested it most likely died of suffocation, probably following an entanglement in a fishing net.

According to experts, these deaths underscore the growing impact of human-induced pressures on marine ecosystems along India’s coastline. Plastic pollution, 'ghost nets' (abandoned or lost fishing gear), and entanglement in fishing gear are emerging as major threats.

Marine mammal strandings have remained relatively high in recent years. Data from the Central Marine Fisheries Research Institute (CMFRI), Kochi, show 171 strandings in 2024 and 161 involving 14 species in 2025. Among states, Goa recorded the highest number in both years—87 in 2024 and 113 in 2025—followed by Kerala (29 and 15). Tamil Nadu reported 14 strandings in 2024, while Maharashtra reported 11 in 2025.

Scientists say the threat is especially high for coastal species such as the Indian Ocean humpback dolphin, which inhabits shallow waters less than 20 metres deep, bringing it into direct contact with human activities. Although strandings have multiple causes, anthropogenic activities are considered the primary driver.

Indian Ocean humpback dolphins accounted for 129 strandings during the two-year period, rising from 47 in 2024 to 82 in 2025. Goa accounted for the majority—33 in 2024 and 68 in 2025—followed by Kerala (5 and 8) and Maharashtra (3 and 4). The Indo-Pacific finless porpoise was the second most commonly stranded species, with 54 strandings in 2024 and 44 in 2025.

CMFRI has recorded marine mammal strandings through its extensive network, but officials acknowledge actual figures could be higher as many go unnoticed. Dr. Ratheesh Kumar Raveendran, senior scientist at CMFRI, said: “Plastic pollution is among the biggest threats to marine biodiversity. Millions of tonnes of plastic enter the oceans each year, persisting for decades. Marine mammals often mistake plastic for food or ingest it accidentally while feeding. Plastic ingestion can cause digestive blockages, internal injuries, starvation, and chemical toxicity.”

He added: “Ghost nets are another growing concern. Made of durable synthetic materials, they persist in the ocean for years, indiscriminately trapping dolphins, whales, sea turtles, dugongs, sharks, rays, and fish. Entanglement can cause severe injuries, restrict movement and breathing, lead to drowning, or result in prolonged starvation.”