In our tours you can find four large groups of animals:
Cetaceans, which are represented by dolphins, whales and porpoises. Most of the sightings are of dolphins but whales and porpoises are also possible to see, check our latest sightings on our weekly update. Cetaceans are the only marine mammals that are frequently observed in Portugal, as seals are very rare. So far there were sighted 30 cetacean species in mainland Portuguese waters.
Birds, that spend the whole year at sea, such as northern gannets, shearwaters, skuas, Jaegers, and petrels.
Sea turtles, are the only representative of the marine reptiles and the most common specie is the Loggerhead sea turtle (Caretta caretta).
Fish, which are mainly the large pelagic species like the sunfish, sharks, the eventual tuna and the swordfish. A huge variety of smaller fish can be also observed.
Invertebrates, mainly the jellyfish which is sighted during the tours, specially the Catostylus tagi that can reach 1m long during early Autumn. A large variety of invertebrates can be observed like pelagic crabs, krill and salps.
The Common Dolphin (Delphinus delphis) the guests’ favourite because they are curious and spend plenty of time close to the boat.
Spotted in virtually in every tour
Group size is on average 20-30, up to 300
Usually swim very close to the boat
The Tagus River receives their visit during Summer
They are identified by the complex colour patterns, with a cross dividing 4 different colours and the distinctive yellowish colour in the front.
This species is the most abundant and therefore it is not a main target of our research. We undertake photo-ID on the conspicuous individuals and develop basic ecology studies about this species.
The Bottlenose Dolphin (Tursipos truncatus) is the “popular dolphin”
Spotted 34 times in 2024. Few times per week, then disappear for weeks.
Group size is on average 10-20, up to 50
Usually swim close to the boat once and then keep the distance
The Tagus River receives their visit few days per year
They are a more discrete species than the common dolphin. However, some individuals of this species can be the most acrobatic species (when they are in a good mood).
Individuals are more than twice the size of the common dolphins and weight 4 times more, these are massive dolphins!
This species feeds on both the water column and the ocean bottom.
In Portugal this species occur in 3 ‘formats’ (ecotypes): Offshore; Coastal and Resident. Our coastal population is nomad and roams along the coast while the resident is settled in a river’s estuary. Portugal has one of the smallest and most endangered resident bottlenose dolphin populations in Europe.
This species is listed on the European Union’s protected species list and therefore its scientific study and monitoring are crucial tasks for its conservation. These species have their own special areas for conservation all over Europe including in Portugal. They are our main study subject and we catalogue every individual that we meet, through photo-ID as well as behavioural ecology.
The Striped Dolphin (Stenella coeruleoalba) is the highest jumper in the area.
Spotted 5 time in 2024, mostly in late summer
Group size is on average 20-30, up to 100
Usually keep some distance from the boat
Never observed close to the Tagus River
This species can be distinguished by the characteristic “brushstroke” of lighter colour to the dorsal fin and the fine lines coming from the eye to the tail.
This species feeds on the water column and individuals are very similar to the common dolphins in size and habits. This usually results in striped dolphins being seen associated with common dolphins, and collaborating on a hunt or just socializing.
This species stays in deep waters, far from human impacts and therefore it is not a target of our focused research. However they require managing of the fish stocks as it’s their main food source. We undertake photo-ID on the conspicuous individuals and develop basic ecology studies about this species.
The Risso’s Dolphin (Grampus griseus) ghosts of the Sea
Spotted 1 time in 2024
Group size is on average 5-20
Usually swim close to the boat once and then keep the distance
Never observed in the Tagus River
Like the orca, they belong to the beakless dolphin family (Globicephalinae&Orcininae). Despite their whale appearance they are also true dolphins.
They are easily distinguishable by their tall dorsal fins and almost white colour, which separates them from the other members of the family like the Pilot Whales.
Pilot whales (Globicephala melas) is the second largest dolphin in the world.
Spotted 1 time in 2024
Group size is on average 10-20
Usually swim close to the boat.
Never observed close to in the Tagus River
There are other ‘false whales’ like the orca. They are deep water hunters and dive to great depths. They travel along the coast but further away from the coast. We also keep a catalogue of all individuals that we meet.
The Orca (Orcinus orca), is the largest dolphin in the world.
Spotted 1 time in 2024, during summer
Group size is on average 5-10
Usually lets us close for short periods at a time
Despite being dolphins, they make the experience more similar to a whale watching experience.
Individuals occur in the area as transients on their annual migration along the Portuguese coast. There are 3 known families that pass by Lisbon Bay and other 2 that might do the same route, but never sighted by us.
It is almost impossible to confuse them, as they have a very peculiar colour pattern, a massive size and males have a 1.8m tall dorsal fin, that cuts the horizon like a sword.
The orcas that can pass in Lisbon belong to the Iberian orca population with slightly more than 30 individuals and are bluefin tuna specialists. As most orcas in Europe, they only feed on fishes. We see them hunting alongside with the common dolphins.
They can be spotted between May and June, in August and in September-October. The fall period is the most when we sighted them more often as there are better sea conditions. They were recorded inside the Tagus and the Sado river a few decades ago. We keep a catalogue of all individuals that we meet.
+Read more about our orcas.
The Harbour Porpoise (Pocoena phocoena) a very shy ‘false dolphin’
Spotted 14 times in 2024, few times per month
Group size is on average 1-2
Swims away from the boat
Regular all year in the Tagus River
They may look like a dolphin but they belong to a different cetacean family, the porpoises. Its distribution is restricted to shallow waters but it is extremely discrete, and usually avoids vessels. It is one of the smallest known cetacean in the world.
The harbour porpoise is also listed on the European Union’s endangered species list, and therefore its scientific research and monitoring are crucial tasks for its conservation. These species have their own special areas for conservation all over Europe including in Portugal. This species is of great interest because a supposedly resident population disappeared from the neighbouring bay in ~2003. Assessing if the individuals sighted in Lisbon bay are from a resident population is a crucial priority.