What is spout?

A blue whale can breath in just 1 to 2 seconds. With each breath, whales replace up to 90% of the air contained in their lungs (compared to 10-15% for humans). Air is expelled from their lungs at high speed (up to 720 km/h recorded by scientists in a young gray whale) through their nose, which is found on the top of their head and is called a “blowhole”. The hot (37°C) air condenses upon contact with the colder outside air and forms a cloud. In addition to the difference in temperature, since the air exhaled is compressed, the difference in pressure between the lungs and the ambient air also causes condensation or vapour. In this mass of expelled air are also water and oil droplets from the upper respiratory tracts or the top of the blowhole.

To each his cloud

Spout characteristics vary by species as a function of their size and the structure of the blowhole: a double blowhole forming a bump on the head for baleen whales (mysticetes), and a single blowhole or orifice at the crown of the head for toothed whales (odontocetes).

  • Minke whale: inconspicuous, 2 metres high.
  • Humpback whale: balloon-shaped (nearly as wide as high), may reach 3 metres high.
  • Fin whale: column-shaped, 4 to 6 metres high.
  • Blue whale: column visible from very far (several kilometres), 6 metres high or more.
  • North Atlantic right whale: V-shaped (two very distinct jets, the orifices of the double blowhole being widely spaced apart), 5 metres high.
  • Harbour porpoise: barely visible but quite loud.
  • Beluga: inconspicuous, 1 metre high.
  • Sperm whale: very slanted (the blowhole is offset well to the left side of the head), 3 metres high.

But beware of hasty interpretations!

A number of factors can influence the height and shape of the cloud: wind that blows the spouts or alters their shape, light conditions and the humidity of the ambient air. The height of the spout also depends on the activity of the animal. It will be more discrete when the whale is resting or minimally active, or when its dives are short and close to the surface.

Magazine

Round-up of 2025 North Atlantic Right Whale News

After being hunted for hundreds of years, the North Atlantic right whale currently faces a number of threats, including entanglements…

| 22/5/2025

After a week of strong winds, we’re eagerly waiting for fairer weather!

Marine mammals were quiet this past week. Did the stiff winds drive them away, or were they simply less visible?…

| 22/5/2025

A Breath of Spring: Humpbacks are Back

Humpback whales are making their return to the estuary this week, much to the delight of the locals. Additionally, the…

| 15/5/2025