At a Glance
- Researchers from Wageningen Marine Research observed the rare Arnoux’s beaked whale in the Southern Ocean during an Antarctic expedition in 2022. This was the first sighting in over a decade of expeditions.
- The team tracked and counted birds and marine mammals using two methods: from observation posts on the ship and helicopter flights when the ship was stationary, leading to three sightings of Arnoux’s beaked whales.
- Researchers reviewed historical data and international research findings, revealing 108 sightings of 1,125 Arnoux’s beaked whales. This challenged the previous belief that these whales prefer deep ocean waters.
- The study suggests a potential connection between Arnoux’s beaked whales and sea ice for feeding or protection. It indicates that the species may not migrate far north during winter, as previously thought.
- These findings contribute to the EWOS pilot program, which aims to improve monitoring of the Antarctic ecosystem and support the establishment of a Marine Protected Area in the Weddell Sea.
Researchers from Wageningen Marine Research and their partners have made a significant discovery in the Southern Ocean. They are focusing on how sea ice affects the food web, particularly the “top predators” like seabirds and marine mammals. During a recent Antarctic expedition aboard the German icebreaker Polarstern in the southern autumn of 2022, the team observed a rare species of whale known as the Arnoux’s beaked whale. This was the first sighting of this species during the numerous Southern Ocean expeditions conducted over the past few decades.
The researchers used two methods to track and count the number of birds and marine mammals. While the ship was moving, observations were made from wooden observation posts on the bridge of Polarstern. When the ship was stationary, additional counts were conducted using a helicopter. Notably, groups of Arnoux’s beaked whales were spotted three times during helicopter flights, a first in eleven previous expeditions dating back to 1988. These sightings were detailed in a study published in Marine Mammal Science.
Arnoux’s beaked whale is rarely seen, making it challenging to understand its behavior and distribution. To provide context for their findings, the researchers reviewed historical sightings, including slides and videos from the 1980s and 1990s and data from international research programs. This review uncovered 108 sightings of 1,125 whales, shedding light on their distribution and habits. Contrary to previous beliefs that these whales prefer deep ocean waters, the data show they are often seen in relatively shallow waters near the coast and ice edges.
The study highlights that Arnoux’s beaked whales may be connected to sea ice, possibly for feeding or protection reasons. This new information suggests that the species does not migrate far north during winter, as previously thought. The findings are part of the Eastern Weddell Sea Observation System (EWOS) pilot program, which aims to improve monitoring of the Antarctic ecosystem and support the establishment of a Marine Protected Area (MPA) in the Weddell Sea.
References
- Feij, B., Kühn, S., Meijboom, A., Van Franeker, J. A., Bornemann, H., Kelly, N., & Schaafsma, F. L. (2024). Distribution of Arnoux’s beaked whales (Berardius arnuxii). Marine Mammal Science, e13158. https://doi.org/10.1111/mms.13158
- Wageningen University. (2024, August 27). Rare whale species observed during recent Antarctic expedition. Phys.Org; Wageningen University. https://phys.org/news/2024-08-rare-whale-species-antarctic.html
