The archipelago of the Azores plays an important role in the marine ecosystem of the North Atlantic Ocean. The area has a very complex oceanographic circulation, influenced by the Gulf Stream and (branches of) the North Atlantic Current and the Azores Current. Oceanographic features of the area show steep submarine walls, ridges and escarpments and a very short continental shelf. It concerns a coastal marine habitat where coastal, pelagic and deep-water ecosystems can be found in close vicinity of each other, resulting in a species-rich and highly diverse marine ecosystem. The Azores form a cetacean hotspot of world wide importance. Yearly over 25 species of resident and migrating whales and dolphins are observed in inshore waters, some of which are severely endangered species.

This indicates that the area could form a critical habitat for cetaceans in the North Atlantic Ocean. Research and monitoring in this particular key-area is therefore of great importance for the conservation of a large number of cetacean species and their habitat.

Due to the absence of a continental shelf and the steep marine walls, whales and dolphins species occur very close to the coast, allowing researchers to use land based observations as an highly efficient and cost-effective tool to study species presence, numbers, general behaviour and temporal and spatial patterns of occurrence.