they capture 150 whales eating together; record since the end of his hunt

Researchers and filmmakers presented videos and photos of large groups of up to 150 fin whales from the south in their historical feeding areas, a record documented with modern methods.

Given the key role of these whales in nutrient recycling, other species in the Antarctic ecosystem, such as krill, could also benefit from their rebound, as published in the journal Scientific Reports.

Fin whales are the largest whales in the world, after blue whales, and humans have hunted both species to near extinction. Following the ban on commercial whaling in 1976, populations of these long-lived but slow-growing creatures are recovering.

I have never seen so many whales in one place and I was absolutely fascinated watching these massive groups feed,” says Professor Bettina Meyer, a biologist at the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI) and the University of Oldenburg, as well as the Helmholtz Institute for Biodiversity. Functional Navy, in Germany.

From March to May 2018, he led an expedition with the research icebreaker Polarstern, in the Antarctic Peninsula regionduring which groups of up to 50 or even 70 fin whales (Balaenoptera physalus quoyi).

The expedition investigated, for example, the effects of climate change on Antarctic krill, which form the base of the Antarctic food web and can measure up to six centimeters. This tiny bioluminescent crustacean is one of the main food sources for fish, penguins, seals and whales.

During the expedition, a team led by the study’s first author, Dr Helena Herr, from the University of Hamburg, and a camera crew from the BBC jointly used the helicopter aboard the Polarstern to conduct reconnaissance flights, counting and filming whale populations.

In 22 flights, the team covered a total of 3,251 kilometers and counted 100 groups of whales, formed by one to four whales each. In addition, the cetacean research team kept watch on deck and spotted a pod of about 50 fin whales near Elephant Island in the Weddell Sea off the Antarctic Peninsula, and later more than 70 at the same location.

“I ran straight to our monitor, which uses acoustic measurement methods to show the presence and size of krill swarms in the water,” recalls Bettina Meyer. And based on the data, we were able to identify the swarms and even see how the whales hunted them,” she said.

But whales don’t just eat krill, they also benefit from it: whale droppings fertilize the ocean, since the nutrients they contain, such as iron, which is comparatively scarce in the Antarctic, are essential for the growth of phytoplankton (microalgae) in the water. In turn, phytoplankton is a food source for krill.

“When the whale population grows, the animals recycle more nutrients, increasing the productivity of the Southern Ocean. This drives the growth of algae, which in turn absorb carbon dioxide from the atmosphere through photosynthesis, reducing the atmospheric concentration of CO2″, explains Bettina Meyer.

The recovery of the humpback populations seems to be a trend: a year after the Polarstern expedition, the whale research team and the BBC returned to Elephant Island with a chartered boat and observed up to 150 animals.

“Although we still don’t know the total number of fin whales in the Antarctic, due to the lack of simultaneous observations, this could be a good sign that, almost 50 years after the commercial whaling ban, the fin whale population common in the Antarctic is picking up”, concludes Bettina Meyer.

*With information from Europa Press.