The wonderful thing about a career in marine biology is how varied the work is. Because the specific subject areas one can focus on are almost limitless, there really isn't a typical day for a marine biologist. Some might research the migration of whales, while others might study the tiny plankton, microbes, and even the seawater itself.
A day for one marine biologist might involve scuba diving for mussels in the morning, bringing them back to the lab for observation in the afternoon, recording any relevant data, and doing some statistical analysis (using a computer) by comparing studies already done by other scientists. A day for another marine biologist may be teaching undergraduate students or guiding postgraduate students into the world of discovery research.
Many marine biologists focus on research papers. For example, a marine biologist may study the effects of oil or chemical spills released into the ocean on plant and animal life. They may then present their research papers at scientific conferences, and/or publish the results of their research in scientific journals.