Winkler scale

The Winkler scale is like a ruler that tells us how much oxygen is in water. Oxygen is a gas that fish and other animals use to breathe, just like we use air. The scale was invented by a man named Albert Winkler, which is why it's called the Winkler scale.

To use the Winkler scale, scientists take a sample of water and add some special chemicals. These chemicals react with the oxygen in the water and create a blue color. The more blue the water turns, the more oxygen there is in the water.

Scientists use the Winkler scale to monitor how much oxygen is in different bodies of water, like lakes, rivers, and oceans. This is important because if there's not enough oxygen, fish and other animals can't breathe and they can get sick or die.

So scientists use the Winkler scale to keep an eye on the oxygen levels in the water and make sure that the fish and other animals living there have enough oxygen to stay healthy.