There are approximately 80 species of dolphins and whales which inhabit our seas, oceans and rivers. Officially, 24 of these species we can find in the Azores sea. Some mammals can only be seen in some periods of the year; the Atlantic Spotted Dolphins do not arrive in the archipelago before June, in other words when water temperature is around 20°C.

It is possible to classify the frequency of observations into 4 categories:
-Frequent: Physeter macrocephalus, Sperm Whale - Delphinus Delphis, Common Dolphin - Tursiops truncatus, Bottlenose Dolphin - Stenella frontalis, Atlantic Spotted Dolphin - Grampus Griseus, Risso’s Dolphin - Globicephala macrorhynchus, Tropical Pilot Whale.
- Random: Stenella Coeruleoalba, Striped Dolphin- Pseudorca crassidens, False Killer Whale - Hyperoodon ampullatus, Northern Bottlenose Whale - Zyphius cavirostris, Cuvier´s Beaked Whale - Mesoplodon bidens, Sowerby’s Beaked Whale - Mesoplodon europaeus, Gervais’ Beaked Whale - Balaenoptera musculus, Blue Whale- Balaenoptera physalus, Fin Whale - Balaenoptera borealis, Sei Whale.
-Rare: Orcinus orca, Killer Whale - Kogia breviceps, Pygmy Sperm Whale - Megaptera novaeangliae, Humpback Whale - Balaenoptera acutorostrata, Minke Whale.
-Never: Steno bredanensis, Rough-toothed Dolphin - Mesoplodon mirus, True’s Beaked Whale - Kogia simus, Dwarf Sperm Whale - Eubalaena glacialis, Northern Right Whale.