Many ecosystems are in danger. When animals start dying in a certain ecosystem, the food chain is altered and more animals die. Things like pollution can also cause problems. To understand why a certain part of an ecosystem's population is dying, you have to collect data. When you collect data, you can make predictions and turn your predictions into solutions.

Includes index.

Help needed -- Claymount Stream -- Where are the fish? -- Call in the expert -- Collecting data -- Stream life -- Predictions can become solutions -- The future -- Problems in the woodland -- Bird study -- Expert help -- Plant data -- Animal data -- Insect data -- Predictions for problems -- Deer on the move! -- Problem-solving activity.