When Riki Ott heard about the Deepwater Horizon oil spill in the Gulf of Mexico, it brought back a nightmare she’s lived with for the past 21 years. Riki was fishing for salmon in Cordova, Alaska in 1989 when the Exxon Valdez ran aground and dumped millions of gallons of crude oil into Prince William Sound. At the time, she hadn't told many people in Alaska that she had a PhD in marine toxicology, but that knowledge helped her as the community took stock of the damage and made sure the voices of the fishermen were heard. Now she’s in Louisiana to help citizens and fishermen there deal with the aftermath of the Gulf spill. One of Riki's biggest concerns is about the potential dangers of chemicals dispersants.