What advise do you have for balancing a Marine biology major with a Spanish minor that allows me the immersion I want in that culture without compromising my learning?

Plan plan plan!! This is super important when trying to complete a demanding major and minor and any other opportunities you want to take advantage of in college. I held a double major and completed one semester abroad with a semester-long capstone internship. I did this by taking the summer before my freshman year to sit down and go through all the courses I needed to complete both my prospective majors at the time so that I could see which courses and core requirements I needed to take and when. This helped immensely with course registration. I would highly suggest going abroad with a program that makes sense with your Spanish minor as cultural immersion (in Japan in my case) was really valuable. If you can't afford a semester, many universities and colleges offer 1 month or shorter programs in different countries that could provide a similar cultural immersion experience.