RTP reports that more whales than ever are being seen in the area, including species normally associated with tropical waters.

Among the most notable sightings are sperm whales, or cachalotes in Portuguese. RTP says these have now been sighted in Algarve waters for the first time, adding another species to the increasingly diverse marine life being observed off the region's coastline.

The reason behind the unusually high number and variety of sightings is now being studied.

Portugal's waters are home to a wide range of cetaceans, which include whales, dolphins and porpoises. Official data on Portuguese continental waters lists several species regularly found along the coast, including common dolphins, striped dolphins, bottlenose dolphins, harbour porpoises, pilot whales, minke whales and fin whales.

Sperm whales usually live in deep offshore waters and can be found in oceans around the world. They are deep divers, travelling far below the surface in search of food, particularly squid.

The latest sightings are not only attracting scientific interest but are also having an impact on tourism.

RTP reports that the number of tourist trips heading out to sea is increasing as visitors look for opportunities to observe whales and other cetaceans in their natural environment.

Dolphin-watching is already a well-established activity in the Algarve, with boat trips operating from several coastal towns. Common and bottlenose dolphins are among the species most frequently encountered during trips off the region, although other marine animals can also occasionally be seen.

From Faro, wildlife-watching boats leave the sheltered waters around the Ria Formosa and head into the Atlantic in search of dolphins and other marine species. Operators in the area report that sightings can also include turtles, ocean sunfish and, occasionally, less commonly encountered cetaceans.

The Algarve's location on the Atlantic and its variety of coastal and deeper marine habitats make its waters important for a wide range of marine life. However, the latest increase in whale sightings appears unusual enough to have caught the attention of researchers.

For now, scientists are continuing to study the phenomenon, particularly the presence of tropical species and the growing number of whales being recorded off Faro.

The sightings offer a reminder of the diversity that exists beyond the Algarve's beaches, with some of the region's most remarkable wildlife found several kilometres offshore.