Dolphin Deaths in Cornwall | Fishing Net Impact Explained

Investigation into Cornish Dolphin Strandings

Fishing nets stand as the primary cause of death for short-beaked common dolphins washing up on the Cornish coast. New research from the University of Exeter and the Cornwall Wildlife Trust highlights a grim reality for marine life in the region. Between 2018 and 2024, more than 860 common dolphins stranded along the coastline. Most of these animals were already dead when they reached the shore.

Experts examined 175 carcasses to determine how these animals died. Their findings point to bycatch—the accidental entanglement of marine life in fishing gear—as the culprit in 39% of those cases. This makes it the single largest category of mortality identified by the team. The study operated under the Cetacean Strandings Investigation Programme, which receives funding from the Department for Environment, Food and Rural Affairs.

Understanding the Factors Driving Mortality

The data reveals that Cornwall functions as a hotspot for dolphin deaths. High concentrations of common dolphins visit these waters, often crossing paths with the local fishing fleet. While bycatch is the dominant issue, the study identified several other significant threats. Infectious disease claimed 25% of the dolphins examined. Another 10% died from live stranding events, while non-bycatch trauma and starvation accounted for 8% and 7% of cases respectively.

James Barnett, a key researcher on the project, performed most of the post-mortem examinations. He observed specific markings on the skin of the deceased animals. These marks suggest that smaller vessels using gill nets or drift nets are responsible for the majority of these incidents. He notes that while reported bycatch deaths have decreased over the last three decades, these numbers remain a serious welfare concern. The industry must prioritize better monitoring of the entire fleet, including the smallest vessels.

Potential Solutions and Industry Challenges

Reducing bycatch requires a blend of technological changes and management shifts. Experts suggest that modifying gear or limiting the time nets remain underwater could help. Acoustic deterrents, commonly known as pingers, offer another path to warn dolphins away from danger. Some fishers in the south-west of England have campaigned for wider access to these devices, as current regulations only mandate their use on vessels longer than 12 meters.

But the application of these tools is not simple. The Marine Management Organisation warns that while pingers keep dolphins at a distance, they may carry their own environmental costs. The government currently supports the Clean Catch programme to test different mitigation methods in specific areas. A spokesperson for the Department for Environment, Food and Rural Affairs stated they are actively working to reduce dolphin entanglement through these trials.

Moving toward a solution involves cooperation between regulators and the fishing industry. Rebecca Allen from the Cornwall Wildlife Trust emphasizes that this is a practical necessity for both fishers and conservationists. Preventing dolphin deaths protects gear and prevents the loss of target catch. The goal is to provide local operators with the right tools to monitor their impact and protect the marine environment. The path forward depends on high-level management of static net fisheries.