Catch and Release

 

TU encourages trout and salmon anglers to voluntarily practice catch and release because of its proven benefits to trout and salmon populations.

TU, and its local chapters and state councils, often advocate catch and release regulations where they are appropriate. Typically, catch and release regulations are most useful on streams and rivers where there are highly valuable populations that are facing heavy fishing pressure. Curtailing harvest in these situations can help increase and sustain trout and salmon populations. Typically, catch and release regulations are most useful on streams and rivers where there are highly valuable populations that are facing heavy fishing pressure. Curtailing harvest in these situations can help increase and sustain trout and salmon populations.

Question: 

What does catch and release mean? Why is it important?