The weather is starting to turn cold and we’re bringing out our winter gear to keep ourselves warm! But have you ever wondered how animals in the arctic keep warm – particularly when they’re in the freezing ocean waters?
The answer is blubber! Blubber is the thick layer of fat that lies underneath the skin of marine mammals such as seals and whales.
Blubber an important part of a marine mammal’s anatomy. It stores energy, insulates heat, and increases buoyancy.
Storing Energy
Energy is stored in the thick, oily layer of blubber. The energy stored in blubber includes both proteins (mostly collagen) and fats (mostly lipids). The ability of blubber to use these stored nutrients means marine mammals are not forced to search for food for long periods of time. Nursing mothers, for instance, build up thick stores of blubber before giving birth. In addition to feeding offspring, mothers cannot regularly search for food. They rely on the energy stored in their blubber
Insulation
Blubber also insulates marine mammals or helps keep them warm in icy waters. This insulation is necessary. Mammals are warm-blooded, meaning that their body temperature stays about the same no matter what the temperature outside is. Keeping a warm body temperature in cold water requires more energy than keeping a warm body temperature in warm water. Some marine mammals, such as sea otters, have a thick fur coat, as well as blubber, to insulate them.
To insulate the marine mammal, blood vessels in blubber constrict, or get smaller, in cold water. Constricted blood vessels reduce the flow of blood, thus reducing the energy required to heat the body. This conserves heat.
Buoyancy
Finally, blubber helps marine mammals stay buoyant, or float. Blubber is generally less dense than the ocean water surrounding it, so animals naturally float.
Take the Polar Plunge!
Our Polar Plunge activity is a great way to show kids how effective blubber is at keeping an animal warm! This activity is great for kids of all ages. Parent supervision is required!
Supplies You’ll Need
- Ice
- Water
- Zip-Lock Bags
- Tape
- Crisco Shortening
- A Bowl
- Timer
- Paper Towels
Activity Steps
Print off the Polar Plunge worksheet and follow the steps below.
1) Fill a bowl with ice-cold water and add ice.
2) Make a prediction of how long you can keep your hand submerged in the ice-cold water.
3) Have one person hold the timer and start it when you put your hand in the water. Keep your hand submerged until you wish to pull it back up. Dry your hand.
4) Record how many seconds you were able to keep your hand in the water.
5) Make a prediction of how long you can keep a hand covered in “blubber” submerged in the ice-cold water.
6) Place your hand in a zip-lock bag and tape around it so that way no water can enter the bag.
7) Dip your covered hand into the Crisco shortening. Have someone help spread a thick layer of shortening over the hand.
8) Once a layer of shortening – a.k.a. blubber – is covering the hand, place it in another zip-lock bag and tape around it so that way no water can enter the bag.
9) Repeat steps 3 – 4.
10) Record your observations.
We would love to see your Polar Plunge! Email your photos to info@discoverystation.org and we might just feature them on our social media channels! Be sure to include your child’s first name, age, and any observations they had about the challenge!
