Bechtel Corporation (Bechtel Group) is the largest construction and engineering company in the United States, ranking as the 5th-largest privately owned company in the U.S. Its headquarters are in the Financial District of San Francisco.
This is immensely valuable in all types of business and every organization needs to hire people who have the aptitude to do these tasks in complex environments. Some biology major graduates do end up working in a field that is directly related to their studies. Health technologists, physician assistants, food science technicians, and environmental science researches, for example.
Because the jobs of a marine biologist are so wide-ranging, their salary is also. A person that has focused on marine biology in college may first get an entry-level technician job helping a researcher in a lab or in the field (or rather, out in the ocean).