Silent Ships, Silent Seas: How New Tech Could Spell Trouble for Whales

Two sperm whales, found dead off the coast of Tenerife after having been struck by ships, are raising serious concerns about the viability of the local population and the increasing risks posed by expanding shipping activity. It has not been established which vessels caused the deaths of these whales—a young, breeding-age female and a juvenile—but local researchers have long warned about the growing high-speed ferry network connecting the islands.

International, but mainly inter-island ferry traffic in Canarian waters has surged in recent years, including traditional ferries, fast ferries, and high-speed vessels. A comprehensive review of Canary Islands Cetacean Stranding Network data from 1999 to 2022 revealed ship collisions affected 81 cetaceans across 12 species (8 mysticetes and 73 odontocetes), with 38 cases confirmed by forensic studies. The average number of ship strikes per year was 3.48 overall, and 2.02 specifically for sperm whales.

Research estimates the local sperm whale population at roughly 240 individuals, primarily adult females and juveniles. With an average of only 2.5 calves born annually, the ship strike mortality rate of about 2 whales per year nearly equals the birth rate, putting the population’s survival at serious risk.

These data, combined with the rise in high-speed ferry routes, underscore the urgent threat ship strikes pose to cetacean conservation in the Canary Islands.

Technological advances promise to replace noisy, diesel-powered ships with silent, lightning-fast electric vessels. While this is a positive step toward reducing carbon emissions and achieving net-zero targets, it ironically intensifies risks to whales. Slower, noisier ships allow whales to detect and avoid them, but the quiet approach of electric ships could lead to more frequent collisions, as whales may not sense an approaching vessel until it’s too late.

ORCA recognises ship strike as the foremost threat to whales globally. Through an expanding survey programme, we play a critical role in identifying high-risk areas and developing mitigation strategies. While measures like speed reductions and hotspot avoidance are effective, they cannot fully eliminate the risk. Continued innovation and strict regulation will be essential to safeguard whales amidst evolving maritime technologies.

Main photo credit: Richard Lovelock