Biggest animal on Earth: Blue whales discovered in Seychelles' waters

Blue whales are the largest animals ever known on the earth. (Phillip Colla)

The presence of blue whales in the Seychelles' waters has been discovered in dedicated scientific surveys and scientists are hopeful that further research is possible on these elusive animals, said the Save Our Seas Foundation in a recent statement.

While the waters of Seychelles became part of the Indian Ocean Whale Sanctuary in 1979, almost nothing is known about the occurrence of blue whales in the island nation in the western Indian Ocean.

Scientists from the University of Seychelles, Florida International University and Oregon State University are uncovering how remarkable Seychelles is for these mammals.

In two field seasons, they have recorded 23 species but one important discovery is the confirmation that blue whales frequent the same ocean where they were historically hunted. 

Blue whales are the largest animals ever known on the Earth and can reach up to 100 feet long and upwards of 200 tonnes.

Dr Jeremy Kiszka, a biology professor at Florida International University and a research associate at the Island Biodiversity and Conservation Centre at the University of Seychelles, said Seychelles' ocean is only beginning to reveal its magic.

"'Of course, recording blue whales was a big moment. [...] It is remarkable to know that the largest animal on earth swims here," Dr Kiszka.

He added that of the "four subspecies we know exist, it's the pygmy blue whale that visits Seychelles. Scientists confirmed that the songs of the Sri Lankan acoustic group were recorded on their hydrophones."

Seychelles was a hunting ground for Soviet whalers in the 20th century and when it became a new member of the International Whaling Commission in 1978, the island nation lobbied successfully to protect the Indian Ocean from whaling.

A blue whale sighted at the SOSF D'Arros Research Centre. (Justin Blake, SOSF) Photo License: All Rights Reserved

Today, there have been five confirmed sightings over the course of five years primarily between December and April.

"Never in my life would I have imagined that the biggest animal on planet earth cruises our oceans here in Seychelles," said Dillys Pouponeau, a research assistant at the SOSF D'Arros Research Centre (SOSF-DRC).

For Pouponeau, the research is a personal fulfilment and she said "The coolest thing is that our work here involves studying not only the smallest animals alive, zooplankton, but also the biggest, blue whales." 

Pouponeau joined the expedition as a digital imaging technician with Oceanic Films, which was filming 'Blue Whales – Return of the Giants' (https://bluewhalesfilm.com/) with funding from the National Science Foundation and HHMI Tangled Bank Studios.

"The Amirantes Islands, of which D'Arros Island is a part, is known to have hosted blue whales and suffered atrocious whaling events. We can't wait to understand the whales' population status around D'Arros. Have they returned? How many are there? Their presence will add value to our marine protected area," said Pouponeau.

Dr Kiszka said, "Since I am also a scientist, I was involved in everything happening on the boat. Here on D'Arros, the research involves surveying in the boat and deploying hydrophones. This gives me hope as an emerging scientist. It also gives me a new sense of stewardship.' And that responsibility extends across the oceans."

He added that "these blue whales have no borders; we need to conduct research on an appropriate scale. And we need to collaborate internationally. It's a phenomenal opportunity to understand these blue whales." 

According to Dr Kiszka, "blue whales are protected because they are no longer legally hunted, but they still face a range of threats. Shipping traffic causes noise pollution and can lead to collisions. Climate change is changing the distribution and abundance of their key food, krill."

Going forward, he said, "We now need to increase our research efforts to assess the abundance of these blue whales and discover why they are using Seychelles' waters. We also need to raise awareness and help the government to protect them better."

Dr Kiszka said that funding needs to be raised to start dedicated research on blue whales and that with his colleagues, they will be asking some critical questions, such as what do these whales do in Seychelles from December to April? What do they eat and how could climate change impact their persistence in Seychelles?