Select Page

Whales and other sea mammals have evolved to keep themselves warm in cold oceans. I wanted to know if this is why whales and other mammals have blubber. I was pretty surprised by what else fat is good for.

Warm-blooded mammals use fat to regulate their temperature in icy waters. Layers of fat also help them stay buoyant, give them a protection level against predators, and give them an extra energy source.

Blubber is very important to warm-blooded mammals to survive in such extreme environments. Here I provide some details of why fat is essential for mammals and humans.

Cougars can be found in North America.  Find out where in this article I wrote.

What is Blubber? 

Blubber is a thick and insulating layer of fat that lies beneath the skin of marine mammals. This fat layer dramatically helps keep these warm-blooded mammals inside the water. 

Mammals that have evolved to live in cold ocean waters have a fat layer to help them survive in icy waters. 

Most marine mammals, such as whales, have fat regardless of where they live, whether in the cold waters around Antarctica or frigid waters near the North Pole. 

During the coldest seasons, the water can reach temperatures below 60 degrees c (76 degrees f). In the winter, most whales dive to depths of more than 500 meters into the ocean, where the water is even colder. Blubber prevents the ’whale’s bodies from freezing in these temperatures.

Cold-blooded marine animals such as sharks, crabs, and fish have different survival mechanisms. Cold-blooded animals do not need an extra layer of fat to stay warm. These animals blend their body temperatures along with the temperature of the water.

Warm-blooded marine mammals, these animals have blubber. This extra layer of fat stores extra digested foods in the form of fatty tissue.  

The adipose tissue contains lipids that have a relatively low thermal conductivity. This extra layer does not conduct heat from the whale’s body, therefore not losing it to the surrounding waters. This is the reason why fat helps to keep whales warm. 

Want to know why whales migrate? Find out in this article I have written.

Why do Animals Need Blubber? 

Plenty of warm-blooded mammals live in icy environments, which is the primary reason they need fat to survive. 

This is the case with seals, whales, and sea lions. All of these animals have to endure freezing environments. These animals find their food in the areas where they have historically lived.

These marine mammals have a layer of blubber, a layer of fat tissues. These tissues insulate the body from losing essential heat. 

Marine animals usually develop these tissues over their life to keep them warm. These tissues are not made just through the food that they eat. It is a physical characteristic that mammals have to develop. 

There are several reasons why sea mammals need blubber. 

Gray whales can be seen in many places in North America.  You can read here to find out where I have written an article.

Blubber Regulates Blood Flow

Unlike other fat tissue, blubber is vascularized. The fat has more blood vessels than distinct layers in the body. 

The layers of fat have more blood vessels for the sole purpose of temperature regulation. It is much easier to lose heat while in water than on land. 

Without fat, sea mammals would have difficulty regulating their body temperatures. Water temperatures are constantly fluctuating, and never one temperature for long. Marine mammals use fat to keep their body temperatures in check compared to the sea around them.

The water temperature drops considerably when the whale gets deeper into the water or migrates to colder regions.  

The blubber constricts the blood vessels. This restriction of the blood vessels reduces the flow of blood to the skin. This mechanism enables sea mammals like whales to spend less energy producing body heat. The restriction of the blood vessels keeps the body warm while, at the same time, reducing the use of energy. 

Do you know why whales slap their tails?  Find out in this article I wrote

Thick Insulation Against the Cold

Among many characteristics that sea mammals have developed over time, fat effectively keeps them warm. 

The fat is thick and dense and accounts for a substantial portion of a whale’s body. Thus, sea mammals have a body mass of about 50% fat. 

This substantial amount of fat is especially the case with marine mammals that live in the coldest regions. In areas such as the Arctic, whales have fat that can develop up to 20 inches thick. 

Minke whale showing size of blubber.
Minke whale showing the size of fat.

If you want to know why whales migrate, I have written an article, which you can find here.

Do all Whales Have the Same Thickness of Blubber? 

The thickness of the fat depends on the species and their environments. 

Some whale species have fat just 1 inch thick, whereas others have a layer of fat that is as thick as 20 inches. 

The thickness of the fat plays a more significant role in determining the climate in which a marine animal or mammal can live. The species of whales found in the colder regions will generally have thicker blubber than species found in warmer temperatures.

Does Blubber Contain Lipids?

The fat contains lipids, which store energy and act as components of cells.

Lipid concentrations in the fat are essential. Lipid concentration plays a crucial role in regulating the temperatures of marine animals.  

The higher the lipid concentration in the fat, the more efficient it is at regulating body heat. 

The sea mammal will not efficiently regulate body heat if the fat has a higher water concentration. 

Humpback whales are enormous, but they do have predators.  Find out what attacks them here.

How Does Blubber Help Whales?

Besides the benefit of regulating marine mammals’ body temperatures, fat has several other benefits. 

All the benefits help these mammals survive and thrive in such cold environments. 

Here are some of the primary benefits that blubber offers to whales:


A layer of fat helps the whales be more buoyant. This is very important given the weight of a whale.

Some species of whale can grow up to 150 tonnes. Blubber, combined with saltwater in the oceans, makes it easier for these mammals.  

This combination helps them rise to the surface of the waters without difficulty. It also helps them to stay buoyant when resting and inactive. 


Blubber also protects whales and other marine mammals against injuries and attacks. The extra layer of fat puts marine mammals in a better position to defend themselves because predators cannot easily penetrate that thick layer.

Shark attacking blue whale
Shark attacking blue whale


Blubber also helps to keep the body organs of whales and other marine mammals warm. Some organs, including the heart, brain, and lungs, must function correctly and courteously. Have you ever wondered how land mammals stay warm? Find out in an article I have written here.


For some whale species, fat can be important as an additional energy source. The layer of fat acts like an emergency food store. 

Marine mammals can use nourishment from the fats and proteins stored in the blubber when there is little food. These extra nutrients can help them to survive when food is scarce.

Fat is the primary energy source in some whale species, such as the blue whale. This helps them, especially when they get to colder environments. Due to the fat, the blue whale is what makes its long migration trips successful.

There are 20 species of mammals in North America that are currently endangered.  Find out what they are here.

What Animals Need Blubber?

It is not just whales that have fat. Several other animals in the oceans use the exact mechanism to keep warm. 

These animals use fat to keep the body warm, protecting vital organs, buoyancy, and energy production. Blubber is found in most marine mammals, including whales, seals, polar bears, sea lions, and walruses.

Ever wanted to go whale-watching? Find out where you can see whales in North America in this guide I have put together.

Why is Blubber Important to Humans?

Humans have been using Whale blubber for many years now, and it is used in almost all aspects of life. 

For Native Americans, whale blubber is a popular food source for many people who live in the Arctic. Blubber is rich in a lot of vital nutrients and minerals.

Blubber is rich in Omega 3 fatty acids and vitamin D. These are the two primary nutrients and vitamins that make it so popular.

Blubber should not be consumed in large amounts due to its toxins. The toxins can be a health hazard and cause tissue damage in humans. Blubber should only be consumed in limited quantities.

Whale oil has been used in soap, leather, and cosmetics. Oil from whales was also used as wax for candles and as fuel in oil lamps.

Is Whale Blubber Still Used? 

Whale blubber is still being used, but most countries are trying to discourage whale hunting. 

The government sometimes allows managed whale hunting to preserve particular cultural heritage groups.

This is only done when the whale population is large enough. Some whale species were hunted for blubber and to obtain whale oil, which almost led to their extinction. 

For this reason, many states are highly cautious about whaling. Endangered species are protected, and their populations are closely monitored.

If you want to know what the ten most giant whales are in North America, I have written an article here.