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Aquatic Resources and Integrative Biology

Student working at the park

Texas State’s location, near many aquatic ecosystems, including San Marcos Springs, the headwaters of the San Marcos River, as well as The Meadows Center for Water and the Environment, Aquarena Center, and the Freeman Aquatic Biology Building, provides students with a unique opportunity for study and research.

Students will learn to integrate scientific, technical, and socioeconomic elements to provide sustainable aquatic resources from local to international levels.

 Contact The Graduate College for general questions about getting started with your application, funding your degree, and more.
If you have program-specific questions after reviewing the program details, we encourage you to contact the following:

Doctoral Program Director
Dr. Michael (Clay) Green
Supple Science (SUPP), Room 232

“The program is inherently interdisciplinary, emphasizing both theoretical and applied approaches to think critically about modern ecological challenges. The broad-based expertise within the department offers students the opportunity to discover and disseminate knowledge on a diverse array of topics across the region and internationally.”

— Adam Duarte, Ph.D. ’15, Postdoctoral Research Scholar, Oregon State University

Course Work

Students entering the doctoral program with an earned master’s degree in an appropriate field must complete 61 hours of graduate course work, which includes 21 hours of core courses and 40 combined hours between elective courses and dissertation research (with a minimum of 15 dissertation hours).

Each doctoral student has a research and study program designed to meet the student’s academic goals, including core skills the student wants to develop. The program also includes a mix of elective courses to provide the scientific expertise and knowledge required to work on complex problems focused on the sustainable use of aquatic ecosystems and their resources.

Degree Course Work Dissertation Total Hours
Ph.D. 46 hours 15 hours minimum 61 hours
Ph.D. 76 hours (for applicants with bachelor's degree only) 15 hours minimum 91 hours
Supple Science building

Texas State’s local resources give students the ability to study habitats for threatened or endangered species and to develop and promote programs for the sustainable use of aquatic resources and ecosystems.

Program Mission

The doctoral program emphasizes original research (including basic and applied) to provide depth and breadth of knowledge in aquatic resources and related disciplines, from the watershed and ecosystem scale down to the population, organismal and microbial scale. Students are engaged in a collaborative research environment among students, faculty, natural resource agencies, nonprofit organizations, and public and private interests. The curriculum stresses active roles for students in intellectual exchange with faculty and peers and in the critique of published research. The program prepares students to identify and solve complex problems relevant to the sustainable use of aquatic resources and ecosystems.

Visit program website ›

Program Faculty

The program’s full-time faculty members have established outstanding research programs in molecular/cellular biology, wildlife ecology, population biology, ecology, aquatic resources, and science education. Faculty have published in top-tier journals and been supported by the National Science Foundation, National Institutes of Health, National Aeronautics and Space Administration, and various federal and state natural resource management agencies. Through education, scholarship, and outreach activities, the department enhances the Texas State image by using the life sciences to help meet the current and future needs of society.

Meet our faculty ›

Career Options

The program facilitates the entry of its students into the professional community of scholars and natural resource practitioners in a manner emphasizing the completion, presentation, and publication of original, creative research. Among graduating doctoral students, approximately 60% go to academia, 15% to federal/state agencies, 15% to the public sector, and 10% to the private sector.

Application Process

Step 1

Review Requirements

Application Deadlines

Deadlines U.S. Citizen International
Fall January 15 January 15
Spring August 15 August 15
Summer I No Admission No Admission
Summer II No Admission No Admission

Application Deadline
This program has a firm deadline.

Funding Information
For scholarship, fellowship or assistantship consideration, applications must be completed by the deadline above.

Decision Timeline
This program reviews applications on a firm basis.

Application Requirements

The items required for admission consideration are listed below. Additional information for applicants with international credentials can be found on our international web pages.


  Review important information about the online application.

Application Fee

  • $55 nonrefundable application fee
  • $90 nonrefundable application fee for applications with international credentials

  Review important information about application fees.

Transcripts & GPA

Applicants with a bachelor's and a master's degree:

  • baccalaureate degree from a regionally accredited university
  • master's degree in biology, chemistry, engineering, geology, or a related natural science field from a regionally accredited university
  • a copy of an official transcript from each institution where course credit was granted
  • minimum 3.25 GPA in all completed graduate course work

Applicants with a bachelor's degree only:

  • baccalaureate degree in biology, chemistry, engineering, geology, or a related natural science field from a regionally accredited university. Applicants with backgrounds in other disciplines will be considered on a case-by-case basis.
  • official transcripts required from each institution where course credit was granted
  • minimum 3.5 GPA in your last 60 hours of undergraduate course work (plus any completed graduate courses)

  Review important information about transcripts. Official transcripts, sent directly from your institution, will be required if admission is granted.

GRE Scores

  • GRE not required


  • mentor recommendation letter from a current Texas State doctoral faculty member in the Aquatic Resources and Integrative Biology program. Visit the faculty list for current faculty and their research interests and contact information. Your mentor must email their letter of support directly to The Graduate College at This letter must be on file before the program's deadline.
  • resume/CV summarizing your educational and professional accomplishments
  • statement of purpose describing your professional aspirations and rationale for pursuing a doctoral degree in aquatic resources
  • three letters of recommendation addressing the substance and quality of your preparation for doctoral study

  Review important information about documents.


Applicants are required to submit TOEFL, PTE, or IELTS scores that meet the minimum program requirements below unless they have earned a bachelor’s degree or higher from a regionally accredited U.S. institution or the equivalent from a country on our exempt countries list.

  • official TOEFL iBT scores required with a 78 overall
  • official PTE scores required with a 52 overall
  • official IELTS (academic) scores required with a 6.5 overall and
    • minimum individual module scores of 6.0

  This program does not offer admission if the scores above are not met.

  Review important information about official test scores.