Ten whale watches were completed between October 2014 and January 2015 using a quasi-experimental design with and without balloon debris retrievals. A link to a post-trip electronic survey was sent two weeks after whale watch tours to adult participants who volunteered to take part in this study. This study showed how witnessing the retrieval of marine debris while listening to a conservation message did have an effect on the reported intended pro-environmental behaviors. Overall, those who were exposed to the balloon retrieval mentioned conservation themes within the open-ended questions more than the control group. This study suggests that pro-environmental changes intended behaviors, attitudes and knowledge did occur and may have produced thoughts and actions in individuals who are now more enlightened and aware about marine debris issues. Contrary to changes in attitudes and intended behaviors, there were no noticeable impacts on reported actual behavior changes from the participants after the whale watch tour.