The more people know, the better decisions they make. Motivate your class, workplace or family to volunteer for stream restoration or storm drain stenciling projects. Make a donation - Even a small donation to an organization concerned about anadromous fishes and their habitat can go a long way. But do your research. Make sure that the group to which you choose to donate shares your priorities and will spend your donation responsibly.
People make their best decisions when they are armed with knowledge.
Share what you have learned - It doesn't do anybody any good to go out and learn a whole bunch of new stuff and then keep it to themselves.