150 whales observed feeding together in Antarctica
It’s a big meeting for ecologists and nature conservationists: the southern rock documented in large groups in Antarctica for the first time since the whaling ban.
A fin whale in the Weddell Sea, near Elephant Island, north of the West Antarctic Peninsula. © 2022 by BBC.
Whales are the Whales the largest in the world, after the blues, and humans have nearly wiped out both species. After commercial whaling was banned in 1976, populations of these long-lived, slow-growing animals are recovering: researchers and filmmakers now jointly publish in the journal Scientific reports videos and photos showing large groups of up to 150 southern fin whales in their historic feeding grounds, more documented than ever with modern methods. These animals play an important role in nutrient recycling, so other species in the Antarctic ecosystem, such as krill, could also benefit from population recovery.
I had never seen so many whales in one place and was totally mesmerized to see these huge groups feeding,
enthuses Prof. Dr. Bettina Meyer, biologist at the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI) and the Helmholtz Institute for Functional Marine Biodiversity, as well as a professor at the University of Oldenburg and co-author of the current study in the journal Scientific reports. The first author of the study is Dr Helena Herr, from the University of Hamburg, who is also a visiting researcher at the Alfred Wegener Institute. Bettina Meyer led an expedition with the research vessel Polarstern from March to May 2018, during which pods of 50 to 70 fin whales (Balaenoptera physalus quoyi), respectively.
Among other things, the expedition studied the effects of climate change on Antarctic krill. Krill is the base of the Antarctic food web; seals and whales feed on this luminescent shrimp, which can measure up to six centimeters, as well as fish and penguins. A crew led by Helena Herr and a BBC film crew together used Polarstern helicopters on the expedition to carry out scientific measurement flights to count whale sightings and film.
Fin whales feeding in the Weddell Sea near Elephant Island, north of the West Antarctic Peninsula. © 2022 by Helena Herr.
During 22 missions, the team traveled a total of 3,251 kilometers and counted 100 groups of whales consisting of one to four animals. The whale research team also avoided helicopter flights and found pods of around 50 fin whales around Elephant Island in the Weddell Sea off the Antarctic Peninsula, and on a second occasion up ‘at 70.
I went straight to our monitor, where we can see if and to what extent there are schools of krill in the water using acoustic measurement techniques. In fact, we were able to locate schools of krill using the data and even see how whales hunted krill. (Bettina Meyer)
Las ballenas no sólo se alimentan de krill, también lo utilizan: las excreciones de las ballenas fertilizan el oceano, porque los nutrients que contienen, como el hierro, que es limitado en la Antártida, son esenciales para el crecimiento del fitoplancton (algas diminutas) in water. Phytoplankton, in turn, is food for krill.
As the whale population grows, the animals recycle more nutrients and the Southern Ocean can therefore be more productive. This allows more algae to grow, which in turn absorbs carbon dioxide from the atmosphere through photosynthesis, thereby reducing the CO2 content of the atmosphere. (Bettina Mayer)
The recovery of fin whale populations appears to be on the horizon: the whale research team and the BBC returned to Elephant Island in a specially chartered vessel the year after the Polarstern expedition and documented up to 150 animals.
Although we don’t know the total number of fin whales in Antarctica due to a lack of synchronous observations, this could be a good sign that the population of fin whales in Antarctica is recovering almost 50 years after the ban on commercial hunting. . (Bettina Mayer)
The International Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) intends to establish a network of Marine Protected Areas (MPAs) in the Southern Ocean. The European Union (EU) first submitted a proposal for an MPA in the Weddell Sea, the Atlantic sector of the Southern Ocean, to CCAMLR in 2016. The scientific data for this proposal has been compiled and assessed by experts from the Alfred Wegener Institute. The proposal for a Weddell Sea MPA as a refuge for cold-loving species is supported by many states, but has not yet been adopted.
Helena Herr, Sacha Viquerat, Fredi Devas, Abigail Lees, Lucy Wells, Bertie Gregory, Ted Giffords, Dan Beecham, Bettina Meyer: Return of aggregations of large whales feeding in historic whaling grounds in the Southern Ocean. Scientific Reports (2022). DOI: 10.1038/s41598-022-13798-7