29.08.2024 – Discovering the deep sea

My career was not exactly straight forward. As a child, I did not dream of spending my life on the ocean. Instead, I spent much of my childhood in mountains and forests and eventually decided to study Geography, Biology and Botany. I can still remember sitting in a botany lecture, the professor had just told us about some extremely isolated mountains in the middle of the Venezuelan rainforest. I already pictured myself climbing these mountains and finding a plant which no one had ever seen before. I guess I was always thrilled by discoveries and the unexpected. Indeed, I lived for a while in rainforests before I made a 180° turn and dedicated my life to whales and dolphins for the past decade of my life. It must be impossible to discover a new species of whales, being such large, conspicuous mammals, you might think? Well actually, there are still new species being discovered in recent years. Most of them belong to the family of Beaked whales (Ziphiidae). Never heard of them before? That makes perfect sense. Even though the family of Beaked whales already counts a minimum of 22 species, many people have never heard of these enigmatic creatures before. Even many of my experienced colleagues, marine biologists and researchers, have never seen one. Some Beaked whale species are only known from strandings and have never been observed alive at sea. And still, we were surrounded by Beaked whales in two of our three tours today. How can we be so lucky?

Most Beaked whales are not larger than 5 meters and extremely elusive animals. Once they hear the engine noise of an approaching vessel, they escape into the depths where they can stay for hours! Yes, you have read correctly. The longest ever recorded dive of a beaked whale took as long as almost 4 hours without taking a breath! And this is why much of our knowledge of beaked whales is left to presumption. What are they doing in the depths? Beaked whales feed on squid. Therefore, they occur in deep ocean habitats. Luckily, we find exactly these habitats just off the coast of Madeira. Our most commonly seen species is the Blainville’s beaked whale (Mesoplodon densirostris), which is also the species that we could observe today. It is also the only species which I have seen to behave so extraordinarily untypical: Calmly swimming closeby boats. On some occasions, even being curious. When they decide to approach us, we can observe the little details and scratches on their skin. Over the last months, I have even been able to recognize some individuals even with the naked eye. There is still so much to study and understand about beaked whales. Hopefully, the observations and photos from our tour can shed a little light onto these marvellous creatures.

by Sarah Kather

Sightings of the day

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

Ribeira Brava

09:30 Atlantic spotted dolphins, Bottlenose dolphins, Blainville’s beaked whales

13:30 Bottlenose dolphins, Blainville’s beaked whales

Stenella

09:30 Atlantic spotted dolphins, Bottlenose dolphins, Blainville’s beaked whales, Risso’s dolphins

14:00 Bottlenose dolphins, Blainville’s beaked whales, Sperm whale

17:00 Atlantic spotted dolphins, Bottlenose dolphins