Within the first hour of observations this day, we spotted a blow 800m away and headed towards it. We noticed some whale footprints* and the Sei whale appeared 80m away from the Atlas, exhaling once before submerging and surfacing again after 5 minutes.
*A footprint is a glassy, smooth circle area which is a consequence of the whale’s forward motion. The extremely powerful motion of their flukes creates a vortex, which is clearly visible on the surface as it is clear and smooth compared the rest of the ocean’s restless surface.
Sei whales are the third-largest known whales in existence reaching lengths of up to 20 meters and look very similar to the other rorqual whale. However, she had a dorsal fin different from the one of a Bryde whale that is more like a hook and at one point we saw her right jaw below the water that wasn’t white, telling us that it couldn’t be a fin whale. Its size was a little bit smaller than a fin whale as well.
Some interesting facts about Sei Whale:
- They are one of the fastest whales and can reach a speed of 50 kilometers per hour for short periods of time
- Sei Whales are present in all the major ocean of the world
- During the colder winter months, these whales will travel towards the warmer tropical/subtropical environments where they and mate and give birth to their offspring.
- These whales are known for creating very loud low-pitched sounds. Downsweep (around 34 to 82 Hertz) and upsweep (around 200 to 600 Hertz) pulsed calls have been recorded in North Atlantic. You can listen to it on DOSIT
- The Sei Whale can retain its blow for at least 20 minutes (more we don’t know…)
- The killer whale is their only natural predator (pollution, traffic, noise, and overfishing are the other threats)
- They tend to be solitary animals, but during the mating season or feeding, they can aggregate.
- The words in the scientific name Balaenoptera borealis mean “northern winged whale”.
- You won’t see the fluke when it dives.
Previously before the whaling era, these marine mammals were a much more abundant species throughout the world, however extensive hunting has caused significant decreases in certain sei whale populations (about 2/3 of them were decimated).
Here you can see their area of repartition:
If you want to learn more about Sei whales we recommand the NOOA website .
Here is also a very nice video about Sei whales from the Falkland Conservation:
Thanks for reading!