23.05.2024 – Into the deep blue

The morning was extremely species-rich. We saw three different species of dolphins, such as the Atlantic spotted dolphins (Stenella frontalis), Short-beaked common dolphins (Delphinus delphis) and Striped dolphins (Stenella coeruleoalba), as well as Sperm whales (Physeter macrocephalus). Of course, both the big and the small ones are marvellous to watch in their own way. However, it is definitely extremely impressive when a gigantic Sperm whale slowly and elegantly lifts its tail and dives majestically into the blue.

Sperm whales are specialists of the deep. They can dive to depths of up to 2000-3000 metres. This ability allows them to reach the depths where their main food, squid, are in their element. Their dives usually last around 40 to 60 minutes, but they can stay underwater for up to 90 minutes before they have to surface again. This is due to their efficient oxygen storage and ability to slow down their heartbeat to reduce oxygen consumption. These large toothed whales have several physical adaptations that allow them to stay underwater for so long. Their muscles have a high concentration of myoglobin, a protein that stores oxygen. They can also dissolve large amounts of nitrogen in their tissue, which minimises the risk of decompression sickness. Sperm whales use their echolocation to navigate the dark depths of the ocean and find prey. They produce clicking sounds that travel through the water and bounce off objects, giving the whale an acoustic picture of its surroundings. These clicks are the loudest sounds produced by an animal and can cover distances of several kilometres.

By Fatima Kutzschbach

Sightings of the day

Ribeira Brava

09:30 Atlantic spotted dolphins, Common dolphins, Sperm whales, Portuguese man-o-war

13:30 Striped dolphins, Bottlenose dolphins

Stenella

09:30 Atlantic spotted dolphins, Common dolphins, Striped dolphins, Sperm whales, Portuguese man-o-war

13:30 Striped dolphins, Bottlenose dolphins, Portuguese man-o-war

16:00 Bottlenose dolphins, Atlantic spotted dolphins 

Click on each sighting to access the photo gallery of the correspondent trip