Get a degree in whatever area of expertise you enjoy and excel.
If you really apply yourself, regardless of what your major may be, you will gain the skills necessary to succeed, whether it's in fishing (in which nothing is ever guaranteed) or some other field.
I know lots of people in fisheries that don't know much about catching fish.
I personally got my degree in engineering and think it benefits my fishing in more ways than a marketing degree (for instance) would -- using critical thinking to analyze conditions and process information; evaluating equipment and knowing its limits, strengths, and weaknesses; making tackle modifications and adjustments; improving on-the-water efficiency and time-management; keeping organized records and data; etc.
It's all about building skills and learning how to apply them.
A lot of the tour pros have very different backgrounds, but they're all using their own individual skill sets to work toward achieving the same goals.