Special | 28m 46s | Video has closed captioning.
Fish are amazing creatures, some species dating back to the time of dinosaurs. Scientists study them to learn about the past, about how humans are changing the environment, even to discover how salmon can swim all the way to the ocean and then travel hundreds of miles all the way back to the stream in which they were born. Learn more from our fish experts.
Problems Playing Video? | Closed Captioning