I am in college doing general studies and getting in as much biology classes as I can as well as wildlife management classess. My passsion is Marine Biology, I decided to drop that and stick to Biology. I want to become a Biologist at one of the Texas lakes (Calaveras, Braunig, Medina, etc.). Is there a certian degree I would need to become a Aquatic Biologist??

Not really. A degree in biology generally is a good grounding for most careers in biologicaly sciences. If your heart is set on aquatic systems then studying relevant taxonomic groups is useful (i.e. algae, fish, invertebrates generally) but broad fields like ecology, are just as important and apply equally to aquatic and terrestrial systems. This is also true for genetics (e.g., I am an evolutionary geneticist but work mostly on fish so I need to know about aquatic habitats).

My advice is to keep your options broad by studying for a general biology degree, but then take the optional courses that interest you the most. We all get better grades when we study things we like and that helps a lot!