In 2018, a multidisciplinary expedition to Antarctica to study the impacts of climate change on krill populations, among others, discovered a joyful surprise concerning one of the crustacean’s top predators: fin whales. Helicopters sent aboard the vessel sighted 100 groups of cetaceans, while observers on deck spotted groups of 50 and 70 near Elephant Island, about 550 miles southeast of Cape Horn. A round trip in 2019 revealed even larger gatherings of up to 150 people at the same location.
The results, published this week in the journal Scientific reports, signal the whales’ return to their historic feeding grounds and hint that the species – Earth’s second-largest behind blue whales – is rebounding after whalers chased it to the edge from the abyss. The International Union for Conservation of Nature (IUCN) Red List also notes that fin whale populations have been increasing since its last assessment in 2018, when the body upgraded the species’ status from endangered. from extinct to vulnerable.
Seeing such a volume of whales in the Southern Ocean is unheard of in decades. Before commercial whaling was banned in 1982, some 725,000 of the animals were killed for commercial purposes, reducing their numbers to less than 2% of their pre-whaling abundance. Today, the IUCN estimates their total population at around 100,000.
While this most recent survey offers a small window into current counts, the researchers’ estimates of species abundance in the region are a hopeful sign. Their observations and calculations indicate that there could be as many as 3,618 fin whales in the bare area around Elephant Island alone. “Even though we still don’t know the total number of fin whales in Antarctica, due to a lack of simultaneous observations, it could be a good sign that, nearly 50 years after commercial whaling was banned, the fin whale population common in Antarctica is bouncing back,” said Bettina Meyer, a biologist at the Alfred Wegener Institute in German and co-author of the survey. Daily Science.
This latest survey confirms a trend lead author Helena Herr has observed in the region for nearly a decade. A 2013 trip to study minke whales led the Australian Marine Mammal Center ecologist to an unexpected gathering of fin whales too, she reminded The New York Times, and other research groups have published similar results over the past 12 years. But it is a 2016 sampling near Elephant Island which, according to the latter Scientific reports article, convinced Herr and his colleagues to do further study.
Having fin whales feed again in their historic haunts could have benefits for the entire ecosystem. When cetaceans nibble on krill, they release iron as a waste product. Higher iron levels in the water can stimulate the growth of phytoplankton, which attract carbon dioxide from the air. Marine scientists call this process the “whale pump”.
While the fin-bounce story is a strong sign that conservation efforts can work, whaling is far from the only stressor for whale populations. Animals regularly encounter commercial and recreational watercraft and can sometimes become entangled in fishing gear. During this time, systemic issues such as ocean noise and temperature changes can disrupt their movements and eating habits.