The Marine Science Institute (UTMSI), located in Port Aransas, Texas, is home to the Department of Marine Science in the College of Natural Sciences. The Institute is dedicated to advancing and sharing knowledge of estuaries, coastal, and blue-water oceans through research, education, and outreach programs. Marine science faculty, students, and professional staff conduct basic and applied research with global reach, from the Gulf of Mexico waters to the polar oceans. The department is well known for its master's and doctoral degree programs in marine science. A Bachelor of Science in Biology: Option III: Marine Science undergraduate degree is available through the College of Natural Sciences at The University of Texas at Austin.

Founded in 1941, the 62-acre UTMSI main campus and 10-acre Port Street campus are strategically located on Mustang Island's north shore, offering unparalleled access to open Gulf waters and the pristine bays and estuaries of Texas. These natural habitats include fresh to hypersaline waters; sea grass and mud flats; oyster reefs; sand beaches; dune areas; the open Gulf; and estuarine nurseries. Core research areas include marine ecosystem structure and function, fisheries biology, organismal biology, fish physiology, and marine biogeochemistry.

The Marine Science Institute facilities include approximately 216,000 square feet of research and teaching laboratories, digital classrooms, study areas, a library, visitor centers, an auditorium, meeting rooms, offices, and seawater for laboratory experiments. A dormitory, apartment housing, cafeteria, and fitness facilities support resident student and visiting scholar needs. The institute's boat basin harbors watercraft ranging from shallow water skiffs to the R/V Katy, a 57-foot trawler.

The Marine Science Institute is home to several unique programs. It manages two federally sponsored programs; the Mission-Aransas National Estuarine Research Reserve and the Beaufort Lagoon Ecosystems Long Term Ecological Research Program (LTER). The Mission-Aransas Reserve, at 186,189 acres, is the third-largest estuarine reserve in the nation and focuses on research, education, and stewardship. The Mission-Aransas Reserve maintains outreach facilities and programs of the Patton Center for Marine Science Education in Port Aransas, and the Bay Education Center in Rockport, Texas. The Reserve also operates the Amos Rehabilitation Keep (ARK), which rescues and rehabilitates hundreds of sea turtles and marine birds annually. The Beaufort Sea (LTER) is a research program along the northern Alaskan Arctic coastline in the Beaufort Sea, and the program is focused on studying the relationship of seasons and Arctic ecosystems. The Institute also operates the Fisheries and Maricultural Laboratory on its Port Street Campus, which conducts research in captive spawning, larval development, nutrition, and physiology of recreationally and commercially important fishes.

Faculty, graduate, undergraduate students, and professional research staff at UTMSI have achieved landmark discoveries in marine science spanning decades of local and global interests. The record of excellence in research, teaching, and mentorship provides an outstanding opportunity for new students interested in marine science career paths.