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The marine and freshwater biology option within the Bachelor of Science in Biology degree requires a broad range of biology, geology, chemistry and marine science courses and requires a summer of field study at the Marine Science Institute in Port Aransas, Texas. The student takes upper-division course work in the physiology, diversity, and ecology of aquatic organisms. Marine biology is a very broad area, so most researchers select a particular area of interest and specialize in it. Specializations can be based on a particular species, group, behavior, technique, or ecosystem.

The Marine Science Institute serves as an internationally recognized center for the study of marshes, bays, the Gulf of Mexico, and the world's oceans. The Institute is dedicated to innovative research, university education, and public outreach. Undergraduate courses at the Institute offer students practical experience in both the laboratory and field. The unique location of the Institute provides students and researchers immediate access to a variety of marine habitats. Students may explore research opportunities and learn more about potential careers related to marine and freshwater biology.

Declare This Major

Current students interested in changing to the marine and freshwater biology major should complete the following instructions:

  1. Complete the entry-level courses (Calculus 1, CH301/302, and BIO311C/D) with at least a C- or higher
  2. View the online information session.
  3. Complete the questionnaire at the end of the session and bring it your advising appointment.
  4. Schedule an appointment with the Biology Advising Center.

Current students who have not yet completed the entry-level requirements should schedule an appointment with an academic advisor in WCH 1.106. Contact the First-Year Advising Center to schedule an appointment and change majors to Biological Sciences entry-level.

Prospective University of Texas at Austin students should visit to learn about the application process and how to declare a major.

Required Courses

For information on required courses, students can view the marine and freshwater biology degree plan. For additional information, view course descriptions by major options, course syllabi, and Frequently Asked Questions.


Marine and freshwater biology is one option within the Bachelor of Science in Biology degree, view all options within biology.

A small sample of directly related careers

Marine Biologist
Environmental Scientist
Biological Technician
Cardiovascular Technologist
Conservation Scientist

Remember: Your major does not (necessarily) equal your career. View a list of career ideas for any major.