Common name

Common dolphin

Latin name

Delphinus delphis

Order

Cetacea

Family

Delphinidae

Life span

>30 years

Social behaviour

Large pods of 10-50 individuals, frequently seen with other species.

Weight

up to 140kg

Length

up to 2.7m

Population trends

Despite their name, the population of common dolphins in the Mediterranean Sea is declining rapidly. In the last 30-50 years, this population has reduced in size by roughly 50%.

Distinctive Features

The common dolphin is characterised by a light yellow hourglass shaped colouration on its sides. They also have a distinctive, curved and pointed dorsal fin with white patches.

Habitat

Typically found in offshore areas, in waters over 200 m deep.

Interesting fact

Similar to many other cetaceans, when the mother is giving birth, other members of the pod keep guard and after the calf is born, it is helped to the surface to take its first breath.

Main threats

Prey depletion (due to overfishing), by-catch, habitat degradation and pollution (noise, chemical and plastic).

Diet

Fish and cephalopods.

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Common name

Striped dolphin

Latin name

Stenella coeruleoalba

Order

Cetacea

Family

Delphinidae

Life span

Up to 45 years

Social behaviour

Large groups of 20 to 100 individuals

Weight

 130-170kg

Length

Up to 2.6m

Population trends

The striped dolphin is the most abundant dolphin species in the entire Mediterranean, with an estimated 500,000 individuals. In 2020, the IUCN Red List listed them as ‘Least Concern’, although a reduction in population size has been suspected over the past three generations.

Distinctive Features

They are easily recognisable by their grey and white stripes that begin at the eye and spread along the dorsal and lateral sides of the body.

Habitat

Typically found offshore in waters more than 200 m deep, in pelagic and benthopelagic zones.

Interesting fact

They are the only species in the Mediterranean Sea that exhibits roto-tailing. This is an agile behaviour involving leaping high out of the water and rapidly rotating the tail while in the air.

Main threats

Prey depletion (due to overfishing), by-catch, habitat degradation and pollution (noise, chemical and plastic).

Diet

Fish, crustaceans and cephalopods.

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Common name

Bottlenose dolphin

Latin name

Tursiops truncatus

Order

Cetacea

Family

Delphinidae

Life span

>50 years

Social behaviour

Pods of 2-25 individuals

Weight

250-400 kg

Length

up to 4m

Population trends

This species is found throughout the Mediterranean, with an estimated population of 52,000 individuals. While the species has shown a 30% decline in population since the 1940s, the Mediterranean population is listed as ‘Least Concern’ on  the IUCN Red List of Threatened Species in 2021. However, the increased interactions of the species with fisheries and aquaculture pose a real concern on the survival of their populations.

Distinctive Features

Recognised by its grey colouration, curved dorsal fin and short, broad, round snout. This species is larger than other dolphins.

Habitat

Found in both in-shore coastal waters and offshore areas.

Interesting fact

Bottlenose dolphins can produce up to 1000 clicks per second when echolocating.

Main threats

Prey depletion (due to overfishing), accidental (by-catch) and deliberate killings, habitat degradation and pollution (noise, chemical and plastic).

Diet

Opportunistic diets; fish, cephalopods, crustaceans.

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Common name

Risso’s dolphin

Latin name

Grampus griseus

Order

Cetacea

Family

Delphinidae

Life span

Over 35 years

Social behaviour

Groups of 3 to 20 individuals

Weight

300-500kg

Length

Up to 4m

Population trends

There are no estimates of Risso’s dolphin population size in the Mediterranean Sea.

Distinctive Features

They have a robust, relatively large anterior body and dorsal fin. Their melon is blunt and they lack a prominent beak. Risso’s dolphins are best characterised by their pronounced white scars.

Habitat

They migrate through open sea, but are typically found in deep pelagic waters, particularly in areas with submarine canyons.

Interesting fact

Their white skin markings are scars, gained during hunting, fights and other social interactions between individuals. A lack of repigmentation causes the scarring to stand out against their otherwise grey colouration.

Main threats

By-catch, noise and chemical pollution.

Diet

Mainly cephalopods, but also fish.

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Common name

Harbour porpoises

Latin name

Phocoena phocoena

Order

Cetacea

Family

Phocoenidae

Life span

25 years

Social behaviour

Generally solitary but can be in groups of no more than 5 individuals

Weight

Up to 80kg

Length

Up to 2m

Population trends

Globally, estimates of harbour porpoise abundance total over a million individuals. They are found in the Baltic Sea, the Black Sea and their surrounding waters, with sporadic strandings recorded in the Aegean Sea.

Distinctive Features

They are identifiable by their plump bodies, rounded head, low triangular dorsal fin and lack of beak.

Habitat

They inhabit coastal and shallow offshore waters. 

Interesting fact

Harbour porpoises are one of the smallest marine mammals.

Main threats

By-catch, habitat degradation and depletion of fish stocks.

Diet

A wide variety of fish, cephalopods and crustaceans.