MN Options for Marine/Freshwater Biology

I am 21, and I am known by everyone around me for really liking fish. I keep freshwater tanks, breed shrimp, planning fish themed tattoo sleeves on both my arms, getting my PADI certification this summer, draw fish all the time, literally everything. I am passionate. I also love learning. I am smart, I went to college full time when I was 16. Due to unforseen circumstances I had to drop out and never graduated, havent been back since, and I am very shameful about it. very.

I've always thought about going to college for Marine Biology since I was a kid, but relocating (I am in Minnesota) is not possible right now. I recently realized I can just do Freshwater Biology, Minnesota has so much freshwater and I live within a few hours of the Great Lakes. Are there actually job opportunities for Freshwater Biology around here? College would be very hard to pay for so im hesitant to make the change.

I like being in the water, observing fish, propagating aquatic plants, writing papers, etc. Im very open when it comes to what kind of work I would do.