Several species of cetaceans inhabit the waters off the Catalan coast, and they can often be seen from the shore or a boat. However, even if you are lucky enough to spot one, it can be challenging to identify the species from a distance, especially if you are not experienced in marine observation. To help you out, here are some tips for recognising the cetaceans commonly found in this region.
Key aspects to identify cetaceans
- Size, colour and behaviour: The combination of these factors can help identify these animals. Some of the main aspects to consider are size, shape, body colouring, distinctive markings, and whether they travel in small or large groups.
- Habitat: The proximity of each species to the coast is another factor to consider. Some cetaceans are more likely to be found in waters closer to shore, where the depth is shallower, while others can only be found in deeper waters.
- Fins: Fins are another distinguishing feature. For example, the dorsal fin, which is usually located on the midline of the back, is a key feature. The shape, size and position of the dorsal fin can vary significantly between species. Some have smaller, rounded dorsal fins, while others have larger or distinctively shaped dorsal fins. In addition, in some species, it is located more towards the front, while in others, it is located more towards the back. The tail, or caudal fin, with its flat horizontal shape, is also characteristic of all cetaceans.
- Cetaceans blow: Cetaceans are mammals, so they have to come to the surface to breathe. They breathe through the blowhole, which consists of one hole on the top of the head connected to the lungs. When they reach the surface, they quickly exhale air through the blowhole and inhale again. The exhalation looks like a fountain of whitish vapour formed by a combination of pressurised air and the layer of water over the animal’s head that rises as the air is expelled. This “blow” is often the first indication of the presence of a cetacean in the area. The number of blowholes is another feature that can help identify the species of cetacean being observed. Dolphins, beaked whales and sperm whales (from the Odontocete family) have only one blowhole, while baleen whales (from the Mysticete family) have two.
Cetacean species along the Catalan coast
Here are brief descriptions of some of the most common cetacean species along the Catalan coastline, highlighting their key characteristics. The species are listed in order from those typically found closer to shore to those that usually inhabit more distant waters.
- Bottlenose dolphin (Tursiops truncatus): This sturdy dolphin, reaching up to 4 metres in length, is easily identified by its grey body, lighter sides, and white belly. A common species in the Mediterranean, it is one of the most iconic, often seen very close to the coast. Its dorsal fin is tall and curved, and group sizes typically range from 2 to 25 individuals, though much larger groups have been observed.
Bottlenose dolphin (Tursiops truncatus) – Natàlia Amigó.
- Striped dolphin (Stenella coeruleoalba): Smaller than the bottlenose dolphin, reaching up to 2.5 metres in length, this species has a colouration that ranges from dark grey on top to white or pink on the underside. It is distinguished by three dark lines extending from the back of the eye: one runs to the dorsal fin, another to the ventral part of the body, and the third to the pectoral fin. This species prefers pelagic waters, further from the coast, where it can be found in groups of dozens of individuals, sometimes in mixed groups with other cetacean species.
Striped dolphin (Stenella coeruleoalba) – Natàlia Amigó.
- Common dolphin (Delphinus delphis): Despite its name, this species of dolphin is not so frequently sighted in Catalan waters. Similar in size to the striped dolphin, it is easily recognisable by its distinctive hourglass-shaped colouring, with yellow sides forming a V-shape. The dorsal fin is triangular, and its body is more slender compared to other dolphins.
Common dolphin (Delphinus delphis) – SUBMON.
- Long-finned pilot whale (Globicephala melas): This species is known for its glossy black colouring and rounded head, with no beak, and can grow up to 6 metres in length. Its dorsal fin has a broad base with a pronounced curve. It is also distinguished by a distinctive ‘W’-shaped spot on its chest.
Long-finned pilot whale (Globicephala melas) – Natàlia Amigó.
- Risso’s dolphin (Grampus griseus): This species has a compact body that can reach up to 4 metres in length and a bulbous head without a distinct beak. Its dorsal fin is high and pointed. One of its most notable features is the numerous white scars on its grey body, which are acquired over the years from interactions with other individuals, prey, or the seabed.
Risso’s dolphin (Grampus griseus) – Natàlia Amigó.
- Sperm whale (Physeter macrocephalus): The largest toothed cetacean in the world, males can reach up to 18 metres in length. It is characterised by its huge head, which makes up about a third of its body, and its dark grey or brown colour. Another distinguishable feature is that the sperm whale usually displays its tail fin at the start of its dives. Additionally, the blowhole is slightly offset to the left side of the head, causing its blow to angle about 45º to that side. This can help differentiate it from the blow of the fin whale.
Sperm whale (Physeter macrocephalus) – Carla A. Chicote.
- Cuvier’s beaked whale (Ziphius cavirostris): This species is hard to spot because of its long dives, which can last over 120 minutes and reach depths of 3,000 metres. It has a robust, compact brown body and a small dorsal fin positioned towards the back of its body. Its brief surface appearances and reluctance to approach boats make it particularly challenging to identify.
Cuvier’s beaked whale (Ziphius cavirostris) – Daniel San Roman.
- Fin whale (Balaenoptera physalus): This is the only mysticete, or baleen whale, commonly found in these waters and it is usually found during the spring months. Unlike odontocetes, which include the other species mentioned above, mysticetes have no teeth but instead use baleen plates to filter their food. The fin whale is the second-largest whale in the world, reaching lengths of up to about 20 metres in the Mediterranean. Its blow is very powerful and its exhalation is quite loud, often audible from a considerable distance. It is characterised by its dark colouration, white belly, and asymmetrical pigmentation on the lower jaw: the right side is white, while the left side is black, making it easily recognisable.
Fin whale (Balaenoptera physalus) – Dani San Roman.
The observation of cetaceans in the wild in Spanish waters is regulated by Royal Decree 1727/2007, on December 21st, which establishes measures for the protection of cetaceans and determines the code of conduct to be followed in waters under Spanish jurisdiction. It is important to bear in mind that, according to article 3.4 of Law 41/2010 of December the 29th, the observation of cetaceans is subject to prior authorisation, which must be granted by the Ministry for Ecological Transition and the Demographic Challenge. Specific guidelines and recommendations are as follows:
Infographics about general rules of conduct for dolphins and whales watching. CC Natàlia Amigó / SUBMON.
In the same way, the flight of drones over these animals is regulated by the same legislation, and only a drone with the appropriate permits can fly over them.
Following these guidelines and respecting the regulations, cetacean watching can be a fascinating and enriching experience. Although identifying these magnificent animals may require some practice, knowledge of their distinctive characteristics will undoubtedly help us to recognise and enjoy the rich biodiversity of the Catalan coast in a more conscious way.
All images have been taken with the permission of MITECO in the framework of the AHAB project, the SCARS project and the CETAMED NORTE project.
