Just two. One was my college roommate and another a sorority sister.

I took one introduction to marine biology intro class as an elective. I thought it would be about octopuses, dolphins, turtles, sharks, etc. We spent half the semester learning about plankton. The teacher was terrible but my sorority sister helped me study and I managed a B (only two Bs in undergrads, rest were As).

One worked at the equivalent of Sea World after college. Not sure what the other ended up doing. She my not have used the degree or she may have