I can tell you this:
"WHAT'S THE JOB OUTLOOK? The employment outlook in this field is not encouraging. The supply of marine scientists far exceeds the demand, and the number of government jobs (the federal and state governments are important employers) is decreasing. Other employers are local governments, aquaria/museums, colleges and universities, and private research laboratories or consulting firms. In fishery science, where the study of fish and marine mammal population dynamics is in the most demand, a strong background in advanced mathematics and computer skills in addition to course work in the animal and aquatic sciences is recommended to get a competitive edge in the job market. Also, more universities are offering courses and programs in fisheries or wildlife management, another increasingly important aspect of the study of fishes, marine mammals, and sea turtles. "
Taken from
NOAA (Feb 28, 2006)
In other words, make SURE you want to do this, because the pay won't be great, and it's getting worse.