Have you ever jumped into a pool of water so cold it took your breath away, instantly covering your body in goose bumps? Such derring-do might make for a refreshing, short plunge, but it can quickly become life-threatening. Heat rapidly leaves your body in near-freezing water, lowering your core temperature to a dangerous condition called hypothermia. In the polar regions, where salt can drop water temperatures to 28.8°F (-1.8°C) your heart can cease in minutes.
So how do so many creatures feel right at home in such cold conditions? Most fish are cold-blooded (ectothermic), which means God designed their internal temperature to depend on the temperature of their surrounding environment, slowing their activity and metabolism as water temperature drops. But warm-blooded (endothermic) mammals are designed differently. They can generate body heat internally; but if they can’t maintain a constant internal temperature (homeothermy), they are in danger of dying from the icy cold. This is where God’s care for creatures in extreme cold is clearly seen.
Warm-blooded mammals that enjoy life in cold waters include whales, seals, sea lions, and walruses. Despite the cold surroundings, they maintain a body temperature similar to that of people, about 99°F. A key to maintaining their internal heat is a thick layer of insulating blubber. This fatty tissue, which may gross us out if we see it on our dinner plate, is a marvel of design.
We sometimes humorously call the fat around our waist blubber, but this is not its technical meaning.
We sometimes humorously call the fat around our waist blubber, but this is not its technical meaning. The word refers to a special type of thick fat and connective tissue located between the skin and body muscles of marine mammals. Heat moves very slowly through this fat. In technical terms, blubber has a “low thermal conductivity,” similar to Styrofoam insulation.
A whale’s fat layer may be more than a foot thick, but thickness is not the main factor in blubber’s effectiveness. The insulating ability depends strongly on its internal water content, concentration of lipids, and blood flow. Blubber is so effective that walruses can lie directly on Arctic ice in complete comfort, even with temperatures reaching -40°F (-40°C). Penguins experience even colder temperatures in the Antarctic, yet they are likewise protected, even in the dead of winter.
Retaining too much body heat can cause its own problems, especially for sea creatures like whales that swim from the Arctic to warm seas. However, God designed their bodies so they can adjust the quantities of water, lipids, and blood flow, thus regulating how effectively the blubber insulates heat.
Blubber serves several purposes beyond protection from the cold. For one thing, fat has a high energy content. So animals can readily draw on this internal energy supply for survival. Whales may eat little or nothing at all for days or sometimes months when they are breeding or traveling long distances.
Furthermore, the distribution of blubber helps streamline the animals’ bodies into rounded shapes. Blubber typically covers all of a sea mammal’s body except for its fins, flippers, and tail flukes—converting it into a torpedo. As a result, the creature glides through water with little effort or wasted energy.
A third important property of blubber is its buoyancy. Without blubber, sea mammals would need to work constantly to avoid sinking. The density of blubber is similar to that of ice, allowing marine mammals to rest effortlessly at the ocean surface.
Many animals, including sea otters, are equipped with fur for insulation instead of blubber, but this is not nearly as effective. Fur retains heat in air pockets, but during deep dives this air gets expelled. Evolution proposes that whales and other sea mammals gradually developed blubber over millions of years, sometime after land animals returned to the sea. In contrast, Genesis 1:21 clearly states that God supernaturally created every kind of sea animal on Day Five of Creation Week.
Each marine mammal is a majestic part of creation. Blue whales, for instance, can grow one hundred feet long and weigh up to 200 tons (181 m. tons), more than twice the size of the largest known dinosaurs. Whales “sing” to each other with complex tones that pass through miles of water. Some whales can plunge more than a mile deep in the ocean and stay submerged for over 90 minutes. If the Creator had not equipped them with a layer of blubber, this would be impossible.
“Let heaven and earth praise Him, the seas and everything that moves in them” (Psalm 69:34).
See for Yourself…
Let’s explore how a whale feels in cold water. With adult help you can make a “blubber glove.”
- Bowl of water
- Several ice cubes
- Four sandwich bags
- Wide duct tape or package tape
- Shortening, such as Crisco, from the kitchen
- Paper towels for cleanup
Make Two Gloves. Shortening is used in cooking to produce soft cookies and moist cakes. This solid form of vegetable oil behaves similar to animal fat and provides a substitute for whale blubber. Scoop 3–4 tablespoons of shortening into a sandwich bag. Now insert a second sandwich bag into the first, kneading or pushing the shortening between the walls of the bags. To prevent leaks, seal the two sandwich bags together around the upper edges with wide tape, leaving the center bag open.
This will make a pocket or glove that you can put your hand into without touching the shortening itself. Try out the glove, spreading out the shortening so that it surrounds your fingers. With two other sandwich bags, make another glove, one inside the other, but this time without any shortening. Tape is optional for this second glove.
Test Each Glove. Place several ice cubes in the bowl of water. When the water is cold, put on your “blubber glove” and dip it into the water. Does the shortening protect you from the chilly temperature?
Now try the non-shortening glove as a comparison. Squeeze out extra air from between the bags, put on this glove, and reach into the water. Does the water feel cold with no insulation?
To experiment further, return to the blubber glove and measure how many seconds or minutes pass before you feel the cold. After you finish, you can keep the glove indefinitely to show friends, or return the shortening to the kitchen container, or dispose of it. To explore other benefits of blubber, moisten your fingers and make a marble-sized ball of shortening. If you place this ball into the water, will it sink or swim? Try it! This shows how whales can rest at the surface of the ocean.