Blue whales: first discovery near Seychelles in decades – what our study found

By Jeremy Kiszka, Florida International University

Blue whales are fascinating animals. At 24-30 metres in length (longer than a basketball court) they are the largest creatures on Earth. They are also among the rarest. Estimates suggest that there are only around 5,000 to 15,000 blue whales left in the world.

Their populations experienced a 89-97% decline due to commercial whaling activities worldwide that started in the North Atlantic in 1868. Blue whales were primarily valued for their blubber, transformed into oil and used in cosmetics and soap, for the lubrication of industrial equipment, and as lamp oil. In 1978, the last deliberate capture of a blue whale was recorded off Spain.

Today, blue whales are found in all oceans except the Arctic. They usually migrate from their summer feeding grounds where they almost exclusively feed on krill to their winter breeding grounds. However, their migration patterns are still poorly understood, particularly in the Indian Ocean, where limited research has been conducted.

Historically, the Seychelles archipelago – off the coast of east Africa – was an opportunistic whaling ground for Soviet whaling fleets en route to and from the Antarctic. In the waters of the northern Indian Ocean, whalers illegally killed more than 1,200 blue whales, including 500 near the Seychelles, between 1963 and 1966.

Since then, no dedicated research had occurred to assess the abundance of blue whales in this region until 2020, when I partnered with the University of Seychelles, Oceanic Films (UK) and my colleague, Kate Stafford, to investigate.

We carried out two expeditions in November 2020 and 2021. After surveying about 5,500km across the northern Seychelles, we had a total of five sightings of up to 10 blue whales.

This was a phenomenal finding. We were prepared to not see any blue whales due to the high level of hunting that occurred fairly recently and absolutely no information was available since the last blue whale was killed in the region in 1964.

Read Full Story https://theconversation.com/blue-whales-first-discovery-near-seychelles-in-decades-what-our-study-found-224558