If I were wanting to get a fishy degree I would pursue aquaculture. It is a field that you can find work and also would give you skills to eventually pursue your own venture if you wanted to. Harbor Branch might be a good route to go since you could intern at some of there commercial operations (ORA would be fun) and maybe get hired when you graduate.

http://www.hboi.edu/aqua/acted_degree.html

As for opening your own LFS...it's not like your going to make alot of money doing that.