© Frederic Bassemayousse / WWF

Somewhere in the open seas of the Ionian, mother sperm whales are babysitting the young of other females in the pod, while they descend to the deep dark underwater canyons in search of deep-water squid. During their dive, they use a complicated echolocation system that transmits sound and receives images, similar to sonar, to locate their prey. 

Sperm whales (Physeter macrocephalus), the third largest animal on the planet, with the largest brain that has ever been recorded, have found an ideal home in the Greek seas. Females and their young live in social groups that may reach pods of up to 13 individuals, while males lead a solitary life. Within these social groups, the young animals learn to dive, locate food, and protect themselves or work together. 

However, these higher predators of the marine food chain and regulators of the marine environment’s health are in danger of extinction. Sounds produced by humans, such as through seismic surveys for hydrocarbon developments, military exercises, and ship propellers, cause lethal injuries. Climate change, driftnet fishing, and oil and plastic pollution have a devastating impact on their survival.

The Hellenic Trench: a marvellous abyss

The home of Mediterranean sperm whales is located in the Greek sea. The Hellenic Trench, with its underwater canyons and cliffs, includes the deepest point in the Mediterranean (Calypso Deep, 5,121 m.) and is a refuge for approximately 200 sperm whales. Its great depths are ideal for the animals to dive in search of food, with each dive lasting up to 90 minutes. The Trench is also the only place found in the eastern Mediterranean where females birth and raise their young, and where social groups and lone males coexist throughout the year. This magical and unique marine world in the offshore Ionian Sea is what we want to save, and we are sure that together we can succeed.


At WWF Greece we fight against oil and hydrocarbon extraction, possibly the most important threat faced by the marine environment and the species that live there. Sperm whales are in danger of hearing loss, behavioural changes and/or dying from the seismic surveys done to locate deposits, while a spill could result in swallowing, contact with or infection due to oil, with serious or even deadly consequences.

Lethal injury can also be caused by collisions with vessels. The constant sound transmitted by large ships can lead to the animals to go deaf. Animals only realise the ship is coming at the very last moment and collision is unavoidable. According to scientific data, shifting itineraries outside the Hellenic Trench areas could reduce sperm whale deaths due to collisions by 70%. That is why, together with research bodies , specifically, the Pelagos Cetacean Research Institute, Ocean Care, and the International Fund for Animal Welfare, we are advocating to the national authorities and the shipping sector to make small adjustments to the itineraries of large ships – changes which do not involve any major cost for the ships, but which can significantly protect this unique species.  

As a result of the coordinated and persistent effort by WWF Greece in cooperation with its partners, starting from early 2021, NAVTEX warnings are being transmitted by the Hellenic Navy Hydrographic Service to ships transiting the area, following the request of the Ministry of Maritime Affairs and Insular Policy and the Hellenic Chamber of Shipping. These warnings  inform mariners of the existence of the sea mammals, drawing their attention to identify and avoid collisions with them.

© Iswanto Arif / Unsplash

Sperm whales are in danger of becoming extinct, despite being protected by international, European, and Greek law. Unfortunately, in Greece the legislation is not implemented, while there is no cohesive network of marine protected areas securing the viability of their population as a whole. The recent issuance of NAVTEX warnings is a key first step by the state in addressing this threat, which also contributes to Greece's meeting its obligation to protect marine biodiversity.

It is also an example of good cooperation between the main stakeholders involved, which must continue and intensify through the monitoring of the implementation of the recent recommendations and further actions to ensure the sustainability of the population of this unique species in the Hellenic Trench and the Mediterranean.

Project leader: Amalia Alberini


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