God gave sharks a keen sense of smell. Some kinds of sharks can smell as little as one drop of blood if it was in 1,000,000 drops of seawater (that’s over 13.2 gallons about 50 liters).
A big kitchen trash can holds about 13 gallons or a little less than 50 liters. Imagine one drop in a whole kitchen trash can filled with seawater.
Sharks are also attracted to the chemicals found in the intestines of many species of fish. Some species, such as nurse sharks, have external barbels (a slender, whisker like feeling organ) near the mouth that greatly increase their ability to sense prey.
Sharks generally rely on their superior sense of smell to find prey, but at closer range they also sense movement in the water, and even use their senses to detect electrical fields created by prey.
God really made sharks cool. Here is a cool way to get just a small idea of just how sensitive a shark’s sense of smell is. Of course, our nose can not even get close to the sensitivity of a shark’s but this fun experiment will give you an idea.
What We Are Going to Do
Discover how sensitive a shark’s sense of smell is.
What You Need
- Six large jars or really big clear cups.
- Red food coloring.
- Some cologne, perfume
- (Optional tape and pen to label jars or cups)
Here Is What You Do
Gather all your supplies from the list above.
(Optional) Place tape on each jar or cup and write on one label of the three containers a number “1″ on a different container write the number “5″ on a third container write “10″. You will have three containers remaining. Repeat the process labeling one of them with a number “1″. Label the next with a number “5″ and label the last container with a number “10″.
Fill each jar (or cup) with clean water.
The remaining three containers should be well separated in the room.
he second container (optionally labeled 5) place 5 drops of cologne. Stir gently to mix.
Here Is What Is Happening
Remember that a shark can smell one drop of blood in as much seawater as it takes to fill a kitchen trash can.
Well, when scientist talk about the amount of one liquid in another liquid like this they do not talk about drops in a trash can or anything like that.
Instead they talk about how many parts per million something is. Then it does not matter if they are talking about one drop in a million drops or one gallon in a million gallons or one liter in a million liters; the ratio is the same.
Instead of writing “parts per million” each time they shorten it to ppm.
So a shark can smell one drop of blood in one million drops of seawater or you could just say:
A shark can smell blood in seawater at 1 ppm
So, when we put food coloring and cologne or perfume in the water we were putting in a certain amount so you can see and smell what it is like.
If your containers have about 1/2 liter of water (a little over 16 oz.) the one with 10 drops of food coloring and the one with 10 drops of cologne or perfume are 1000 ppm (that is 1000 times stronger than a shark needs to be able to smell blood)
Of course, the container with 5 drops is half that or 500 ppm. That is still 500 times stronger than sharks needs.
The last container with only 1 drop is 50 ppm (still 50 times stronger than a shark needs).
God has made everything wonderful. It is amazing to learn about the wonderful things He has made.
So God created the great creatures of the sea and every living and moving thing with which the water teems, according to their kinds, and every winged bird according to its kind. And God saw that it was good.