Invasive species are nothing new to hunters. The public has often turned to sportsmen when certain animals move in where they are not supposed to be. Missouri's response to the increasing wild boar populations has been a policy of "Shoot on Sight," where no matter the season or type of equipment, hunters who see wild pigs are encouraged to harvest as many as possible. When rivers and ponds begin to clog with carp, bowfishing tournaments are a relatively common answer.
Anglers in Colorado are now faced with the arrival of predator fish that are choking populations of trout, as well as other non-game fish in local streams and rivers, as detailed by Scott Willoughby in his recent article in the Denver Post.
http://www.denverpost.com/willoughby/ci_26529296/water-wolves-pose-threat-trout-colorado?source=pkg#disqus_thread
A number of endangered fish are at risk of extinction, and while I disagree with Mr. Willoughby about the enthusiasm of outdoorsmen to act to save an endangered species (in friendly discord of course) it is without a doubt the sportsmen who will answer the call to action.
With new regulations concerning certain species of fish that you are likely to encounter on an expedition, it is even more important to double check the fishing regulations in your area. Game wardens and wildlife officials will take these new rules concerning invasive species very seriously and something as simple as "catch and release" could land you in trouble if you release an invasive species though legally caught.