Humpback whales – Madagascar – CetaMada – Reportage 01

March 14th, 2015

Laryngeal bag.

“How a thirty tons UFO pops out of the water? ”

Olivier Adam, Professor at the University of Paris Sud Orsay, has a colourful language. Translation: how can the humpback whale that weighs up to 36 tones propel its body completely out of the water in such a spectacular leap? This marine mammal is undeniably known for its acrobatic performances. Tourists travel thousands of miles to watch the live action. Scientists try to understand. The reason of these jumps has already attracted attention. Olivier Adam lists the assumptions. To remove parasites? “Personally I do not believe it.” Attract females? “May be”. To communicate? As an acoustic specialist, Professor does not scan this option: sounds could spread on the surface when the animal falls into a foam splash. Get its bearing, perhaps? He smiles: “In Guadeloupe, to St Francois, there is a large white cross and therefore the whales jump in front of the cross to get their bearing…”. The public laugh. Here is a researcher who knows how to talk to his audience. Too many scientists speak and publish reports only comprehensible to their colleagues.

 

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One question is rarely asked: the how of these jumps? Muscle power of the beast is obviously part of the answer. But would few caudal fins kicks be enough to lift such weight? Especially because it is not rare to observe the “breach” (jump in the jargon of the enlightened) coming one after another. The energy consumption required would be such that the animal is hiding  a “trick” to propel its mass a few meters above the surface several times in a raw.

Olivier Adam has a theory. To understand it, we must find the film “Ocean” by Jacques Perrin in our video library and press forward to an amazing scene (19’52 ”). This part was shot in Sainte Marie island with the help of CETAMADA. The image was recorded probably close to a depth of 30 meters. It shows the great blue and a sand bar at the bottom. The whale comes from the right, it “glides” closer and closer from the sand. It comes so close that if it remains unresponsive it could be called “the first humpback whale wallowing in front of the camera” (laughter from audience). Yet, against all odds, the mammal freezes … and flies up. The moment is so graceful that nobody questioned how. “This is an incredible combination of factors. The whale comes so close to the ground that it has to contract its stomach and breath in one seconds in the laryngeal sac. We can see it. And the cameraman is here, filming! “raves Olivier Adam.

 

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Laryngeal bag! This envelope is part of the respiratory system of the humpback whale. It can both receive air from the lungs and excel air. This back and forth system enables the whale to extend its breath. But what’s more, according to Olivier Adam,  the laryngeal bag helps it to go up when it swims too close from the sandy bottom … How? The phenomenon is well known to scuba divers. Add air in your Buoyancy Control Device and you go up, your buoyancy becomes positive. Take a deep breath, which is adding air into the lungs, and you will find the body move up. Olivier Adam recalls the film by Jacques Perrin, where this is exactly what the whale is shown to do. She sent air from the lungs into the laryngeal bag and lifted her head to anticipate the rise. No need for the use of  its long pectoral fins nor its tail, the mammal finds its positive buoyancy. This system could be of great help when it gives its first caudal kicks from 20 meters deep with the intention of a spectacular jump. Laryngeal sac would be, in some way, a launching ramp to Exit.

 

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That’s where we are. Olivier Adam’s theory needs more research. Scientists will try to clarify the matter. They will spend time and energy. Just to understand how a whale jumps out of the water. It takes a healthy enthusiasm to dedicate his life to such simple things.

 

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* Olivier Adam’s conference was held in St. Marie, Madagascar, in August 2014. It was organized by CETAMADA, organization for the conservation of marine mammals, with who Professor  Adam has developed the Baobab Project.

 

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