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With the contribution of the Life financial instrument of the European Union


Of the 14 species of marine mammals that have been recorded in the Greek seas, 9 of them reside here permanently. These are the mediterranean monk seal Monachus monachus, the bottlenose dolphin Tursiops truncatus, the striped dolphin Stenella coeruleoalba, the  Risso's dolphin Grampus griseus, the common dolphin Delphinus delphis, the fin whale Balaenoptera physalus, the sperm whale Physeter macrocephalus, the Cuvier's beaked whale Ziphius cavirostris and the harbour porpoise Phocoena phocoena. 

The remaining 5, that have an intermittent presence in the Greek waters are the the humpback whale Megaptera novaeangliae, the common minke whale Balaenoptera acutorostrata, the false killer whale Pseudorca crassidens, the beaked whale Mesoplodon densirostris and the rough-toothed dolphin Steno bredanensis.


Scientific name: Monachus monachus

A member of the pinniped family, the Mediterranean monk seal is the rarest seal on earth and is among the 10 most endangered species on the planet. Today, approximately 600 monk seals still remain worldwide and more than half of them, live in the Greek Seas.
They avoid human presence and hide.

When the seals come ashore, they select inaccessible sea caves, rocky shores and empty beaches.
Monk seals dive to find food, often making deep dives. While diving, their nostrils close so that water does not come in and their whiskers spread out, working as a sensory organ.

Dives can last from 5-15 minutes and can reach 190 meters deep.

Their favorite food includes octopus, but also eat different species of fish, many of which are also consumed by humans. This of course doesn’t make them the best friend to fishermen, who, many times, see the seals as competitors.

In Greek Seas, monk seals can be found almost everywhere. However, they are mostly concentrated in the Northern Sporades, Cyclades, Dodecanese, and Ionian islands.


Scientific name: Physeter macrocephalus

The sperm whale is one of the largest marine mammals in Greece. Its most unique characteristic is the large head that is almost rectangular in shape and has a very narrow and small lower jaw. It has the largest brain of all other animals on the planet and lives in very deep seas.

The sperm whale’s deep dives can last more than 1 hour! Its favorite food is giant squid that live at great depths.

Sperm whales have highly developed social behaviors that are unique in comparison with other marine mammals. The females live in groups of 10-12 individuals, forming very strong and lasting relationships. Females give birth and raise their young in groups. In these communities, the female whales help each other, protecting each other during birth and raising their young together.

In Greece sperm whales can be found along the Hellenic Trench (that runs from the Western Ionian Islands and Peloponnese to Southern Crete and Southeast Rhodes), in the Myrtoon Sea and in the Aegean Sea areas, especially where the water is very deep.
Based on our current knowledge, the Greek Trench is not only the most important area for sperm whales in Greece, but also for the entire Mediterranean.

In Greece sperm whales can be found along the Hellenic Trench (that runs from the Western Ionian Islands and Peloponnese to Southern Crete and Southeast Rhodes), in the Myrtoon Sea and in the Aegean Sea areas, especially where the water is very deep.
Based on our current knowledge, the Greek Trench is not only the most important area for sperm whales in Greece, but also for the entire Mediterranean.


Scientific name: Delphinus delphis

In Greece sperm whales can be found along the Hellenic Trench (that runs from the Western Ionian Islands and Peloponnese to Southern Crete and Southeast Rhodes), in the Myrtoon Sea and in the Aegean Sea areas, especially where the water is very deep.

Based on our current knowledge, the Greek Trench is not only the most important area for sperm whales in Greece, but also for the entire Mediterranean.

The common dolphin is colorful and has the most complex body color patterns of all cetaceans. The body is colored black, grey, yellow, and white.

To search for food, they form small groups. The dolphins hunt during the night, rest in the morning and interact with other common dolphins. They feed mainly on small fish that live close to the sea surface (sardines, anchovies).

They can be encountered near the coast and in the open sea.
In Greece we find them scattered around the Aegean, the Corinthian Gulf, and especially in the Thracian Sea. A very small population exists in the Ionian Sea.


Scientific name: Phocoena phocoena

The Harbour porpoise is the smallest toothed whale in the sea and also one of the “shyest” animals. In contrast with dolphins, it is very rare for them to approach a boat. Although shy, they are among the most studied and hunted cetaceans as they live in shallow water and close to shore.


It is an endangered species.

The harbour porpoise is the smallest marine mammal in Greek Seas. Its mouth is small and forms a smile.

It feeds on small fish that live close to the surface, but complements its diet with fish that live in deeper waters. Its dives are short and usually reach a depth of 40 meters.

Until the end of the 90s, when the species was sighted in the Aegean, the harbour porpoise was believed to be extinct in the Mediterranean Sea. Today, the existence of a small population at the Northern Aegean and most especially the Thracian Sea is considered to be certain. These are the only areas, in the whole Mediterranean, that we find harbour porpoises.


Scientific name: Grampus griseus

Risso’s Dolphin is the largest dolphin species permanently encountered in Greek Seas, but it is also the rarest.

It is born with a uniform grey color and a white chest.


A feature unique to the species is that many light-colored scratches cover their entire bodies, which are the result of bites from other Risso’s dolphins during fights. Scars may be found on other dolphin species, but Risso’s dolphin get more wounds which are so deep that they become permanent. In fact, as a result of many bites, older Risso’s dolphins may appear white in color.
They can dive up to 500 meters to catch their favorite food, squid.

Risso’s dolphin lives in open seas.

In Greece, they are found in the Myrtos Sea, northwest of Crete, the Sporades, and in Chalkidiki.


Scientific name: Tursiops truncatus

The bottlenose dolphin is the most familiar dolphin to people, as it can come into direct contact with humans because it lives near the coast and is influenced by human activity. Because of its friendly behavior, humans unfortunately capture them for exhibitions in zoos, aquariums, and even television shows, depriving them from their freedom and social behavior.

Bottlenose dolphins are lively and playful animals that breach out of the water and many times meet to surf on bow waves from traveling boats. A main characteristic is the shape of their mouth that gives the impression that they are smiling.

Because they live close to shore, they don’t need to dive in deep water to find food. They are fast swimmers and can easily surpass a speed of 30 kilometers per hour. They have extremely flexible and adaptable diets, and they hunt many different species of fish as well as octopus and squid.

In Greece, bottlenose dolphins can be found in all coastal areas, narrow bays, and around and between islands. It is also the only dolphin species that lives in the closed gulf of Amvrakikos. It is rare to see these dolphins in the open sea.


Scientific name: Stenella coeruleoalba

Today, the striped dolphin is the most commonly found species of dolphin in Greek waters. They often form groups and play in front of the bows of the ships. Their main characteristic is a thin black stripe that starts at the eye and ends at the abdomen.

It is a keen diver that can reach deep depths (200 meters or more) and hunts squid, although it also eats fish.

In the Corinthian Gulf, striped dolphins form groups with common and Risso’s dolphins. The coexistence of these species has not been observed anywhere else in the world as a permanent phenomenon.

Striped dolphins can be found in all Greek Seas with depths of 200 meters.


Scientific name: Balaenoptera physalus

Fin whales are mysticeti, in other words, baleen whales. They are the largest marine mammals living in the Greek Seas and the second largest mammal, in terms of size and weight, in the world (second to the blue whale). It is one of the fastest whales and is a migratory animal (although in the Mediterranean Sea they seem to have a single permanent location).

The length of an adult fin whale is approximately 22 meters and its weight can reach up to 70 tons. It is streamlined in shape and has a pointy head. Its back is dark grey, while its abdomen is colored white. On its neck there are many horizontal folds (like an accordion), thanks to which the fin whale can open its mouth very wide to feed on krill (zooplankton) and small fish.

Fin whales are found in the oceans, mostly where depths exceed 2.000 meters.
In Greece, fin whales have been observed in the Ionian Sea, but in recent years they have been also observed very close to the shore, such as in the Saronic Gulf.


Scientific name: Ziphius cavirostris

In shape, Cuvier’s beaked whale resembles a large, perhaps “prehistoric” dolphin. It is a very elusive animal. It can dive for more than one hour, spends little time at the surface, and does not breach out of the water. Most of the knowledge we have of Cuvier’s beaked whales comes from animals that have stranded dead ashore.

They hunt mainly squid at profound depths. A recent study showed that the animals can dive to 2.000 meters in search of food. The latter is the deepest reached by any mammal. It can hold its breath for up to 85 minutes!

Cuvier’s beaked whales live in very deep seas, such as the Hellenic Trench.
They are also often observed south of Crete and west of Lefkada island.


Scientific name: Megaptera novaeangliae

The humpback whale is known for its acrobatic breechings out of the water and for its “melancholic” song-like communication with other members of its species. Every year it makes the longest migratory journey of any mammal on earth! Its broad fins are the largest extremities of the whole animal kingdom and have given it its scientific name.

Unfortunately Humpback whales were widely hunted by whalers, and today it are threatened with extinction.

It feeds on krill and small fish that it hunts with a very unique method. A group of whales work co-operatively producing a bubble net that encircles the fish, disorientating them.

Though humpback whales have only been observed 14 times in the Mediterranean Sea, two of those, have been sighted in Greece (in the Myrtos and Ionian Seas).


Scientific name: Balaenoptera acutorostrata

Minke whales are rare visitors to Greek Seas. They are among the smallest and thinnest whales. This is the reason why the first whalers did not hunt them. Once the great whales began to disappear, whalers began to hunt these small whales.

Even though over the last 100 years, more than 100.000 Minke whales have been killed by whalers, hunting unfortunately continues even today by Norway and Japan.

Minke whales are mostly found in the Atlantic and Pacific Oceans.
They have rarely been seen in the Mediterranean Sea. In 2000, a young Minke whale carcass was found floating off Skiathos island.


Επιστημονική ονομασία: Pseudorca crassidens

False killer whales are rare in Greek Seas.
It is an Odontocete species, resembling dolphins (like Killer whale) and is much larger than the other dolphins that live in Greek waters. As its name suggests, it looks like a Killer whale.

The common feature of Killer whales and false killer whales is that some populations (outside of the Mediterranean), attack other, smaller marine mammals.
However, the false killer whale makes less use of its sharp teeth to eat marine mammals, as its favorite food is tuna.

False killer whales are mostly found in the marine area of Cyprus and Israel.
In Greece, sightings of these whales are very rare. Until now, one group of false killer whales was observed off the coast of Chios and one whale was found dead in the Argolic Bay.


Scientific name: Steno bredanensis

The rough-toothed dolphin lives in the oceans. It can dive to great depths and stay underwater for more than 15 minutes. Many rough-toothed dolphins have been captured in the past for display in aquariums and/or to feature in shows.
It has recently been shown that there is a permanent population (although small) in the Mediterranean.

Τελευταία αποδείχθηκε ότι υπάρχει μόνιμος (και μάλλον μικρός) πληθυσμός τους και στη Μεσόγειο.

Rough-toothed dolphins live in warm and tropical waters around the world, far from the shore.
They have been encountered in the Mediterranean Sea.

In Greece, only one report exists of a group of rough-toothed dolphins west of Kefalonia island.


Scientific name: Mesoplodon densirostris

Beaked whales are very similar in form and habits with Cuvier’s beaked whales. they are one of the least known mammals on earth because it is very difficult to observe them in their natural environment.

There are 14 species of beaked whales in the world. Three species of these have been observed in the Mediterranean (M. densirostris, M. europaeus and possibly M. bidens).

In Greece we have a mixed reference to a mixed pod of Cuvier’s beaked whales and Beaked whales (M. densirostris) off the shore of Kefalonia.

monk seal
sperm whale
common dolphin
harbour porpoise
risso's dolphin
bottlenose dolphin
striped dolphin
fin whale
cuvier's beaked whale
humpback whale
common minke whale
false killer whale
rough toothed dolphin
beaked whale

The Thalassapedia site was designed by the environmental organizations, MOm/Hellenic Society for the Study and Protection of the Monk Seal and WWF Greece, in cooperation with the cetacean research institutes, Pelagos and Tethys.


18 Solomou Str., Athens 10682

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