25

Furry river otters often sound like squeaky toys. They like to fight each other or frolic in the water. Seeing these cute, playful animals is good fun. It is also good news for the environment.

PLAY

26

The population of otters can indicate how ………………… the environment is. The otters experienced a steep drop in numbers in the 1900s.

HEALTH

27

This was because of extensive fur hunting and toxins in the water. They are not considered endangered today, though. Otters look for habitats with clean water and a lot of healthy fish.

HUNT

28

Researchers look for contaminants and parasites in otter excrement. This helps scientists learn about the health of the surrounding environment and its food sources.

SCIENCE

29

For example, the Elizabeth River was long considered a "dead river" because of pollution. It is now flourishing. As a result, in the past five years, a great many more otters have been seen there.

POLLUTE