I think you will definately get in somewhere and be able to persue your dream in marine bio. I would recommend just taking a few additional classes somewhere so your GPA is >= 3.0, just so you make the cutoffs that some schools employ.
I would highly recommend looking at Moss Landing Marine Laboratories. Fantastic and well known school focusing on marine science research and fieldwork. You can apply through a number of CA state schools. I got my M.S there and found it to be an amazing program. I got in with a 3.2 GPA, + strong work experience and a undergrad pub. PM if you have any questions about the program or faculty.
I would also continue looking for RA jobs in marine bio. Lots of opportunities posted daily here.
http://wfsc.tamu.edu/jobboard/
I think if you can get a year or two of research experience, maybe be a coauthor on a publication you will be competative.
I know that if you are a NOAA fisheries observer for 6 months, they have a scholarship you can use for grad school. My friend just went this route and ended up at OSU. This can make your app much more competative. Plus the observer postiion pays very well, you could do that, save some money up and then apply.