Conservation groups in the Great Lakes region are "celebrating" a very big anniversary: zebra mussels were discovered 20 years ago in Lake St. Claire. Zebra mussels have become the poster invasive species, drowning out native mussels and clinging to pretty much anything that stays underwater for more than 20 minutes.

While zebra mussels get the press, there are more invasive species choking out our native wildlife and destroying ecosystems. What do you think the most dangerous invasive species is?

If there has been a theme to Heroes of Conservation nominations, its that a lot of people are working hard to save the salmon on the Pacific coast, but it seems that no matter how many hours sportsmen are dedicating to the effort, the salmon stock continues to decrease. Already, the early salmon season on the Oregon and northern California coast has been canceled, and officials are saying not to expect good fishing (or any fishing) this year.