You may have thought this through a ton and know that it will be perfect for you. But think about being in the fishing industry for a second:
Will working in the industry make you less likely to enjoy fishing like you currently do?
-I'm currently a college sophomore, and I also enjoy playing golf, but not nearly as much as I did when I was in my first couple years of high school. I started working at a golf course while in high school, and grew to nearly hate the sport for about a year and a half time period. Why? Because, by working at a golf course I was forced to be around it instead of choosing when I wanted to. This completely burned me out on it to the point where I no longer wanted to play competitively and lost a lot of my game. This is just an example that I have to give you. Will being around fishing everyday make you not want to fish as much?
How hard is it to get into the industry?
-I have quite a few friends who are Sports Management majors, which is great, IF they can find a job in the field after graduation. However, there are only so many jobs in the field compared to the amount of people that desire these jobs. I'm not sure, but I would bet that the fishing industry isn't much different. There are probably many people who have the same hopes of getting into the industry that you do.
All of that being said, if it is truly what you want to do, then by all means, work hard and go for it. Just like previously mentioned, marketing might be your best bet if you don't want to get into the science/biology side of things (I don't blame you one bit). However, you will at some point in your college career have to take the math, science, and english courses that you say that you dislike. Nearly all schools will require at least one (probably two) of each of these to fulfill many of your general education requirements during your freshman and sophomore years.