Humpback diving

Have you ever wondered how whales manage to survive and live in these cold waters around Iceland (and even further north!), especially now as winter is approaching and temperatures continously dropping? 

All marine mammals, not just whales, but also dolphins, seals, walruses have a very special fat layer, also 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.

Blubber is different to other types of fat as it is much thicker and contains many more blood vessels than the fat found in land animals, including us humans.

The reason whales don't have it as easy as for example fish is the fact that they're warm-blooded and have a similar body temperature as us humans of about 37 degrees celcius - which of course, they have to maintain. In cold waters, maintaining a certain temperature requires more energy than in a warmer surrounding. In order to better insulate the body, 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. 

You might be wondering now why they wouldn't just have fur 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.

- Sarah

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