The Environmental Issues in Oceanography (EIO) are web-based, critical-thinking projects that guide students in applying the concepts of oceanography and scientific reasoning in analyzing a range of immediate, relevant environmental issues. The goal of these projects is not only to draw students' attention to some pressing ecological issues, but to help the instructor in training the students to gather, evaluate, and analyze information as a scientist would in order to draw their own conclusions—a skill that will benefit students for the rest of their lives.