The Sperm Whale of the Mediterranean Sea: Giants of the Deep
- Virginie Wyss
- Aug 30
- 4 min read
Updated: Sep 1
The sperm whale (Physeter macrocephalus), the largest of the toothed whales, inhabits nearly all the world’s oceans, including the Mediterranean Sea. Within this semi-enclosed basin, their presence carries both mystery and importance, as these whales reveal the resilience and fragility of marine life.
Population and Distribution
The Mediterranean sperm whale population is relatively small and isolated from the global population. Current estimates suggest fewer than 2,500 mature individuals inhabit the region, with particularly important subpopulations concentrated in the western and eastern Mediterranean basins. Unlike their counterparts in the open Atlantic, Mediterranean sperm whales are often encountered along continental slopes, submarine canyons, and deep-sea trenches—places that provide rich hunting grounds.
Notable hotspots include:
The Hellenic Trench (Greece), one of the most important breeding and feeding areas.
The Ligurian Sea (between Italy, France, and Monaco), part of the Pelagos Sanctuary.
The Alboran Sea (between Spain and Morocco).
These regions represent critical habitats where whales feed, breed, and raise their young.
Characteristics of the Mediterranean Sperm Whale
Sperm whales are renowned for their massive, squared heads, which can comprise up to one-third of their body length. Males can reach lengths of 16–18 meters in the Mediterranean, though they are generally smaller than those found in the open ocean. Females are smaller, usually around 11 meters.
They are deep divers, capable of plunging to depths exceeding 1,000 meters for more than an hour in search of squid, their primary prey. Each dive is a feat of endurance, supported by remarkable physiological adaptations such as collapsible lungs and oxygen-rich muscles.
When and Where to See Them
Sperm whales can be seen year-round in the Mediterranean, though the best chances for encounters occur in summer months when calm seas make sightings easier. Whale-watching operators in Greece, Italy, and Spain offer opportunities to observe these majestic creatures, though encounters require patience and respect for their space.
Their Unique Codas
One of the most fascinating aspects of sperm whale life is their use of “codas,” rhythmic patterns of clicks used for communication. Mediterranean sperm whales appear to have distinctive coda repertoires, which may differ from those in other oceans. These acoustic dialects suggest the presence of cultural identity and strong social bonds within family groups, known as “matrilineal units.”
Codas are not only vital for communication but also for navigation and hunting, as sperm whales rely on echolocation in the dark depths of the sea.
Interesting Facts
Longevity: Sperm whales can live over 70 years.
Social Structure: Females and young form tight-knit pods, while adult males often roam alone, returning seasonally to breed.
Largest Brain on Earth: Their brains can weigh up to 9 kilograms, the heaviest of any animal.
Cultural Transmission: Like humans, sperm whales seem to pass down knowledge and traditions across generations.
Threats to Mediterranean Sperm Whales
Despite their resilience, sperm whales face numerous threats in the Mediterranean:
Ship Strikes: Collisions with vessels are a leading cause of mortality.
Bycatch: Accidental entanglement in fishing gear can lead to injury or death.
Noise Pollution: Increasing underwater noise disrupts their communication and navigation.
Plastic Pollution: Ingestion of marine debris poses a growing danger.
Habitat Degradation: Overfishing and climate change threaten their prey and ecosystems.
The Mediterranean population is considered Endangered by the IUCN, highlighting the urgency of conservation efforts.
Photo Identification: Becoming a Whale Guardian
If you are fortunate enough to encounter a sperm whale in the Mediterranean, consider it a rare gift—and an opportunity to help protect these giants. One of the most valuable things you can do is photograph the whale’s tail fluke (its tail). Each fluke is unique, like a fingerprint, and offers scientists crucial clues about the life and movements of individual whales.
After your encounter, you can share your photos on Happywhale, adding as much detail as possible—such as the date, the number of whales you saw, and the GPS coordinates. With this simple act, your observation becomes part of an international research effort to better understand and protect sperm whales. (Learn more in our dedicated article on photo-identification).
A Sperm Whale Fluke from the GREC Catalogue
In the Mediterranean, several photo-identification catalogues exist, most of them focused on tail fluke markings. The GREC (the French Research Group on Cetaceans, from which these fluke photo comes) and the Tethys Institute are leading references in this work. Recent studies have also expanded coverage to the southern Tyrrhenian Sea, adding to a collective effort to map, follow, and protect these deep-sea giants.
Conclusion
The sperm whale of the Mediterranean is both a symbol of strength and a reminder of fragility. Their deep-diving lives and mysterious codas speak to a world beyond human perception—an underwater realm that thrives on connection, memory, and survival. Protecting these whales means safeguarding not only a species but also the health of the Mediterranean Sea itself.
References
Notarbartolo di Sciara, G., & Gordon, J. (1997). Bioacoustics: Sperm whale codas in the Mediterranean Sea. Aquatic Mammals, 23(3), 307–321.
Frantzis, A. (1999). Sperm whale presence and distribution in the Mediterranean Sea. Marine Ecology Progress Series, 183, 241–250.
IUCN Red List of Threatened Species. (2022). Physeter macrocephalus. Retrieved from: https://www.iucnredlist.org/species/41755/160983555#population
ACCOBAMS. (2021). Conservation of cetaceans in the Mediterranean and Black Seas. Retrieved from: https://accobams.org
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