John Sumpter is a person that we talk about. He is a scientist who studies animals that live in the water. He wants to understand how different things in the water, like pollution or medicine, affect these animals.
John Sumpter is a curious person who asks a lot of questions about these water creatures. He wants to know what they need to grow and be healthy, just like we need to eat our vegetables and exercise to be healthy.
Sometimes, John Sumpter sees that the animals are not okay. Something might be wrong with their bodies or they might not be able to make babies. So, he tries to figure out what is making them sick or how they can make more babies.
By doing this, John Sumpter is helping us understand how the things we do can affect the animals that live in the water. If we stop doing things that harm these animals, they can be healthy and we can enjoy swimming, fishing, and other water activities.