IT’S ALL ABOUT THE BLUBBER
Have you ever wondered how whales manage to survive in these cold waters around Iceland (and even further north!), especially now as temperatures started to drop again near to freezing, fresh snow has fallen and is covering our beautiful Cheek Mountains – and winter will surely be knocking at our doors soon enough?
BLUBBER!
All marine mammals, not just whales, but also dolphins, seals, walruses, have a very special fat layer, the so-called blubber.
This thick layer of fat provides insulation from the cold ocean temperatures at the same time as it stores energy and improves buoyancy. It therefore is, in many ways, a crucial part of these animals' anatomy.
Blubber, which is also called adipose tissue, lies directly under the skin of all marine mammals and covers their entire body except for their fins, flippers and flukes. It is different from other types of fat as it is much thicker and contains many more blood vessels than the fat found in land mammals, including us humans.
However, like all mammals, whales are warm-blooded. Their core body temperature is similar to ours, approx. 36,6°C-37,2°C. In water though, maintaining a certain temperature requires more energy than on land as heat loss occurs 27 times faster in water than on air at the same surrounding temperature. Therefore, in order to better insulate the body, especially in cold waters as around Iceland, the blood vessels in the blubber get smaller (they constrict), which reduces the flow of blood and hence the amount of energy required to heat the body.
So why don’t whales grow fur – just like land based mammals or even other marine mammals – as for example seals?
The main reason is that whales dive and often if they do so, they dive really deep (unlike seals). Fur traps heat in air pockets close to the body. As for the seal, this is a perfect solution as it stays close to the surface, but given the extreme pressure whales are facing as they dive to the depths of the oceans, these air pockets would be pushed out while the hair flattens to the body with increase of the water pressure. In other words, due to the loss of these air pockets and a consequent loss of trapped heat, the whales wouldn't be able to protect their body from the cold while diving.
Text & Photos: Sarah Arndt (captain / guide)