<p>Not sure if you are already in college or not, but if not, enroll in a university with a strong marine biology program. In a relatively narrow field like marine biology, the school that you train in matters. Then, as soon as you can, get some experience in marine biology through internships (either paid or volunteer - if you can swing it). You will find opportunities within labs at the university or through NOAA science centers, USGS science centers, and some coastal state agencies. The experience will do a few things for you. First, you will get a sense of what marine biologists actually do. You will find they spend less time in the field (e.g., exploring reefs) than you might expect and more time in the lab processing samples and in the office analyzing and writing. Second, you will begin to make contacts, which will help with future opportunities, and you can find out how people who are employed as marine biologists got to those positions - what did they study and where did they study/work. Third, after you find out what marine biologists actually do and what it will take to be employed as a marine biologist, you may find that it’s not for you, and it’s better to discover that early than late. (You may find that it is exactly what you want and you are willing to do what it takes - I hope you do.) But if you find it is not for you and you are in a university then there will be other options for you to explore as you discover your path in life.</p>