![\"Codamozza](\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2026\/09\/08134319\/Codamozza-whale.jpg\")
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- Collisions with ships are a leading anthropogenic killer of the Mediterranean\u2019s two endangered large-bodied cetacean species, sperm and fin whales.<\/em><\/li>\n
- In 2025, thousands of vessels traveled through the Mediterranean\u2019s key whale habitats at speeds above 15 knots (28 km\/h), the threshold at which vessel strikes are almost always fatal, according to an analysis by Magma Magazine and Mongabay.<\/em><\/li>\n
- Using vessel and whale telemetry data, Mongabay created a visualization that illustrates how dense maritime traffic poses a continuous threat to whales in the Mediterranean.<\/em><\/li>\n
- Nascent solutions include vessel speed restrictions, rerouting ship traffic to avoid whale habitats, and systems that alert ships to the presence of whales.<\/em><\/li>\n<\/ul>\n
OSTIA, Italy \u2014 Standing before the carcass of a sperm whale on a beach in Ostia, near Rome, in 2023, Lisa Stanzani had no doubts about the animal\u2019s cause of death. The marine biologist could see clear signs that this one had been killed by a vessel\u2019s propeller.<\/p>\n
She recognized it from the wound on its head: a colleague had sent her a video of the injured animal near the island of Ponza, some 100 kilometers (60 miles) away, a couple of weeks earlier. \u201cThis means it died slowly, in agony. As with many collision cases, death isn\u2019t instantaneous,\u201d Stanzani, the founder of Sotto al Mare, an Italian cetacean research and conservation association, told Mongabay during an interview in Ostia.<\/p>\n
It was a young whale with a wound about a meter (3 feet) long. \u201cFor such a deep and clean cut to penetrate the skin of a sperm whale, it must have been a propeller,\u201d she said.<\/p>\n
Sperm whales sleep vertically, just below the surface of the water, and the wound near its eye matched the height of a vessel\u2019s propeller. \u201cWhen a cetacean sleeps, half its brain is inactive,\u201d Stanzani said. \u201cAnd sound dispersal is different underwater. It\u2019s not easy to detect an approaching boat.\u201d<\/p>\n
![\"Marine](\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2026\/09\/08140524\/Lisa-Stanzani-in-Ostia-2.jpg\")
Marine biologist Lisa Stanzani, founder of Sotto al Mare, an Italian cetacean research and conservation association, in Ostia, Italy. Image by Federica Rossi for Mongabay.<\/figcaption><\/figure>\n The vessel strike problem<\/h2>\n
Though sperm whales (Physeter macrocephalus<\/em>) and fin whales (Balaenoptera physalus<\/em>) are typically associated with vast oceans, the Mediterranean is also home to populations of these large cetacean species. Both populations are classified as endangered by the <\/a>IUCN, the global wildlife conservation authority. Globally, more than 90% of shipping routes<\/a> overlap with whales\u2019 migratory paths, and the Mediterranean is a phenomenally busy sea, hosting 15% of global shipping activity<\/a> despite accounting for less than 1% of the world\u2019s ocean surface. Against the backdrop of rising maritime congestion in the Mediterranean, conservationists fear collisions could drive the disappearance of this sea\u2019s giants.<\/p>\n
Fin and sperm whales are slow to reach reproductive maturity, and their losses have outsized impacts on the ecosystem. Describing whales as \u201cthe biggest warriors against climate change,\u201d Aylin Akkaya, scientific director at the Turkish NGO Marine Mammals Research Organization (DMAD), told Mongabay in a phone interview that large cetaceans are the \u201cspoon in the soup,\u201d feeding in the depths before excreting nutrient-rich waste at the sea\u2019s surface. This fertilizes microscopic organisms like phytoplankton, which absorb the greenhouse gas carbon dioxide and produce about half of the world\u2019s oxygen. In addition, during their typically long lives, whales sequester<\/a> many tons of carbon in their large bodies as they feed and grow. When they die, their carcasses can sink to the seafloor, carrying that carbon with them, where it may remain locked away for centuries.<\/p>\n
![\"The](\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2026\/09\/08140537\/Sperm-whale-sent-by-Barbara-Mussi.jpg\")
The sperm whale whose carcass was seen by Lisa Stanzani in September 2023. This photo of the injured animal was taken off the Italian island of Ponza a few weeks before it died. Stanzani said the deep cut visible on the whale\u2019s head was almost certainly made by a vessel\u2019s propeller. Image courtesy of Oceanomare Delphis Archive.<\/figcaption><\/figure>\n - In 2025, thousands of vessels traveled through the Mediterranean\u2019s key whale habitats at speeds above 15 knots (28 km\/h), the threshold at which vessel strikes are almost always fatal, according to an analysis by Magma Magazine and Mongabay.<\/em><\/li>\n