Seen from a distance, it looked like a thick fog across the horizon. However, as the ship approached, the sea bubbling as 150 fin whales, the second largest creature on the planet, dived and rushed towards the surface of the water.
Six weeks after a nine-week expedition near the coast of Elephant Island, northeast of the Antarctic Peninsula, researchers came across the largest fin whale gathering ever recorded.
“This was one of the most spectacular observations I have ever had,” said Helena Hair, a marine mammal ecologist at the University of Hamburg. “The fin whale seems to be crazy because of the large amount of food it faces. It was really thrilling.”
Dr. Herr and her colleagues recorded the return of numerous fin whales to the waters that once made up their historic feeding grounds. A paper published in the journal Scientific Reports on Thursday.. This study gives a glimpse of the good news that it is an otherwise awkward landscape for global biodiversity, especially for marine species.
Humans are accelerating extinction at an unprecedented pace, according to UN assessments. In the ocean, recent modeling estimates that global warming caused by continued greenhouse gas emissions could lead to mass mortality of marine species by 2300.
However, the recovery of fin whale populations “shows signs that species may recover with management and conservation,” Dr. Har said.
For most of the 20th century, the sea scene around Antarctica was significantly different. Between 1904 and 1976, commercial whalers landed on abundant feeding grounds, killing an estimated 725,000 fin whales in the Southern Ocean and reducing their populations to just 1 percent of their pre-whaling size.
Many species, including fins, sperm, and sei whales, after a decade-long campaign by environmental groups to save whales when the International Whaling Commission’s Parties finally resolved to ban whaling in 1982. Was already on the verge of extinction. ..
However, 40 years after the ban on commercial whaling, researchers studying other species in the Southern Ocean began to notice an increase in fin whale numbers.
This was the case for Dr. Herr and his colleagues in 2013. At that time, they were investigating minke whales when they “accidentally” encountered a large herd of fin whales. They decided to apply for funding to study the resurrection of fin whales.
In 2018 and 2019, researchers returned to the Antarctic Peninsula for the first dedicated study of fin whale populations. Through aerial surveys, researchers recorded 100 groups of fin whales sized from 1 to 4 individuals. They also recorded eight large groups of up to 150 whales gathered to feed.
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The study “confirms that this pattern is still ongoing and even stronger,” said one of the first researchers to record an increase in fin whale populations during the krill study. Jarrod Santora, a fish biologist at the US National Oceanic and Atmospheric Administration, said. (He was not involved in this new study.)
Whale researchers have warned that not all types of whales have successfully rebounded since the ban on whaling. Fishery biologist Sally Mizurock, who has been studying whales since 1979 and has not been involved in the study, described the fin whale as “very successful.” Unlike other species, such as the blue whale, fin whales can forage over long distances and feed on a variety of food sources.
Scientists don’t understand why some of the meetings were so big. Dr. Har said the scenes they witnessed had at least some similarities to historical reports written before the spread of commercial whaling. For example, naturalist William Spare’s Bruce explained during an Antarctic expedition in 1892 that he saw a whale’s back and blast extending “from horizon to horizon.”
Recent studies have suggested that the recovery of whale populations is good not only for whales but for the entire ecosystem through a concept called “whale pumps”. Scientists believe that when whales eat krill, they return the iron trapped in the crustaceans to water. It can then use carbon dioxide for photosynthesis to boost phytoplankton, a microorganism that functions as the basis of the marine food chain.
Since fin whales carry krill to the surface, they can also promote the success of other predators such as seabirds and seals, Dr. Soundtrack said. “There is much more cooperation and symbiosis than we normally admit to the ecosystem.”