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.
All Media © Archipelagos Institute of Marine Conservation
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.
All Media © Archipelagos Institute of Marine Conservation
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.
All Media © Archipelagos Institute of Marine Conservation
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.
