One of the great parts of my job, is that I get to work with many specialists in various fields connected to the Polar regions. After yet another great Blue Whale encounter, where one whale even swam underneath the bow, I decided to make use of these specialities and ask my whale specialist colleague Ursula Tscherter if she could tell some things about these magnificent animals. Here the first part:
The blue whale is an air-breathing animal, which has to hold its breath when underwater. The optimal timing of is diving and breathing pattern is crucial. Breaking the surface in a continuous forward movement, it has a short period of time available to breathe. Blue whales, like other cetaceans, usually initiate they exhale before breaking the surface. This catapults the water near the blowholes and in the respiratory passages into the air in visible droplets. As the exhale is of exploding nature, the air is forced upwards at a speed of several hundred kilometres per hour, creating a visible and audible vertical blow. Most of the remaining time, when the blowholes are above the surface, is then used for inhaling. A whale usually surfaces in a sequence each time taking up oxygen before staying underwater for extended time periods.
The blowholes are situated behind a splashguard and are closed when the surrounding and controlling muscles are relaxed. To open the airway the whale contracts these muscles in a conscious act. This differs strongly from terrestrial mammals, which have a breathing reflex no matter what they do. Imagine yourself when sleeping, eating or socialising having to interrupt this activity to get outside to breathe. Once we understand this, we also know that a boat nearby a whale has the potential to disturb and affect the whale’s need to optimise its breathing pattern.