Even if you have been doing this work for a long time, there is always something surprising. We started off with a huge school of Atlantic spotted dolphins (Stenella frontalis), which sought the boat’s proximity in Spotted style. Shortly afterwards, we went a little further out to see the Sperm whales (Physeter macrocephalus). And something incredible happened. A Sperm whale came straight towards us with a large squid in its mouth, only the head was missing. It slowly approached, turned and swam round the boat as if it wanted to show us its catch. Or was it a sashimi service?
The favourite food of large toothed whales consists mainly of squid, especially large species such as giant squid (Architeuthis spp.) and colossal squid (Mesonychoteuthis hamiltoni). Sperm whales are masters of the deep sea. They reach hunting depths of up to 2000 metres. Their impressive ability to hunt under extreme pressure and in complete darkness is supported by their excellent echolocation system. They use clicking sounds to precisely localise their prey. In addition to squid, Sperm whales also eat fish, including deep-sea fish such as grenadiers and blackheads. However, the majority of their diet consists of squid. In regions where giant squid are rare, they switch to smaller squid. Their high calorie requirements explain the large amount of food they need each day, estimated at around one tonne. Interestingly, beak remains of squid that cannot be digested are often found in the stomachs of sperm whales. These remains provide researchers with valuable information about the animals’ diet and hunting behaviour. Despite their impressive hunting skills, Sperm whales are opportunistic predators and adapt to the available food supply. The role of Sperm whales in the ecosystem is crucial as they contribute to the balance in the food chain. By consuming large quantities of squid, they influence the population of these species, which in turn stabilises the marine ecosystem. Their diet therefore reflects not only their adaptability but also their ecological importance.
Wow, in the afternoon the bush drums of the sea were beating. Two Sperm whales interacted with each other by slapping their flukes again and again on the sea surface.
Unfortunately, there was also a goodbye today. Our colleague Sarah is setting off on new adventures today. Thank you for being there. Good luck and good luck!
A special day, because today is also a birthday to celebrate. It’s the birthday of our senior boss Claudia. Happy Birthday!
By Fatima Kutzschbach
Sightings of the day
Stenella
09:30 Atlantic spotted dolphins, Sperm whales
13:30 Sperm whales