For the first time since the ban on whaling, dozens of southern fin whales were filmed feasting together in a ‘thrilling’ Antarctic spectacle, hailed by scientists on Thursday as a sign of hope for the world. second largest animal in the world.
Ocean giants are second in length to blue whales, with slender bodies that help them glide through the water at high speed.
However, they could not escape industrial whaling and were slaughtered to near extinction during the 20th century as hunters systematically destroyed whale populations across the planet.
“They’ve been reduced to one or two percent of their original population size,” said Helena Herr of the University of Hamburg, lead author of the research published in the journal Scientific Reports.
“We are talking about a few thousand animals left for the entire southern hemisphere area.”
While scientists say southern fin whale numbers have slowly rebounded since whaling was banned in 1976, there have been few sightings of these mysterious animals in large groups on their historic feeding grounds. .
But in scenes Herr described as “one of nature’s greatest happenings,” researchers and filmmakers were able to capture footage of up to 150 fin whales in Antarctica.
Drone footage, shot by BBC wildlife filmmakers, shows the fin whales diving and scurrying through the water, blowing great gusts of air at their surface, as the birds fly through the sky above ‘them.
“The water around us was boiling, as the animals were coming up all the time and causing splashing,” Herr told AFP.
“It was exciting to stand there and watch it.”
Unofficially, the team dubbed it the “fin whale party” as the huge creatures feasted on swirling masses of krill.
During two expeditions in 2018 and 2019, researchers recorded about 100 groups of fin whales, ranging from small gatherings of a few individuals to eight huge congregations of up to 150 animals.
Previously, registered feeding groups had a maximum of a dozen whales.
Using data from their surveys, the authors estimate that there could be nearly 8,000 fin whales in the Antarctic zone.
– ‘Ecosystem engineers’ –
Fin whales can live to be around 70 or 80 years old when left alone and only have one calf at a time. Herr therefore said that restoring populations is a slow process.
She said the increase in the number of southern fin whales is an encouraging sign that conservation measures can work, although she noted that other threats include being struck by boats.
The International Union for Conservation of Nature now lists fin whales as “vulnerable” and estimates the global population at 100,000, most of which are in the northern hemisphere.
More whales could also be a good sign for the health of the ocean in general – and even efforts to fight climate change.
Whales feed on iron-rich krill, but they also defecate in surface waters, returning nutrients to the ocean that help spark the growth of tiny phytoplankton, the foundation of the marine food web.
Like land plants, phytoplankton carry out photosynthesis using the sun’s rays to convert carbon dioxide into energy and oxygen.
They’re “ecosystem engineers,” said Herr, who first spotted a large group of whales by chance in 2013 while on an Antarctic minke whale research mission.
Now she’s planning more missions to investigate the lingering mystery of these giants of the oceans – where they breed.
“We don’t know where they go,” Herr said, adding that much more is known about northern hemisphere fin whales.
Herr’s team was able to put satellite tags on four animals last year, but a mission to return to Antarctica with more tracking equipment was postponed until next year by the pandemic.
– Operations –
This elusiveness is all the more surprising given the size of fin whales.
The animals can grow to around 27 meters (88 feet), although Herr said they now tend to average 22 meters, especially after whaling targeted the larger creatures.
In total, some 700,000 fin whales were killed during the 20th century for the oil in their body fat.
All whale populations in the region were ravaged, from the largest blue whales to the smallest minke whales until commercial whaling was halted in a series of deals in the 1970s and 1980s.
“It’s an example of how humanity deals with resources,” Herr said.
“They exploit them for as long as they can and only stop when they have no more commercial value. As long as you can make a profit, they will be exploited.”