Unofficially, the team nicknamed it the “fin whale party” as the enormous creatures feasted on swirling masses of krill.
In two expeditions in 2018 and 2019, researchers recorded a hundred groups of fin whales, ranging from small gatherings of a few individuals, to eight huge congregations of up to 150 animals.
Previously, recorded feeding groups had a maximum of around a dozen whales.
Using data from their surveys, the authors estimate that there could be almost 8,000 fin whales in the Antarctic area.
“ECOSYSTEM ENGINEERS”
Fin whales can live to around 70 or 80 years old when left alone and have just one calf at a time, so Herr said the recovery of populations is a slow process.
She said increasing numbers 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 as 100,000, with most of these in the northern hemisphere.
More whales could also be a good sign for the health of the ocean more generally – and even efforts to tackle climate change.
Whales feed on iron-rich krill but they also defecate in the surface waters – returning nutrients to the ocean that help spark the growth of tiny phytoplankton, the foundation of the marine food web.
Like plants on land, phytoplankton photosynthesise using the sun’s rays to turn carbon dioxide into energy and oxygen.
They are “ecosystem engineers”, said Herr, who first spotted a large group of the whales by chance in 2013 during a research mission into Antarctic minke whales.
She now plans more missions to investigate the enduring mystery of these ocean giants – where they breed.
For all the latest world News Click Here
