Department of Wildlife & Fisheries Science, Texas A&M University

Education:

Ph.D. University of Texas (1997) 
M.S. University of Puerto Rico (1991) 
B. A. Gustavus Adolphus College (1985) 

Specialty:

Ecology of estuarine, coastal, and pelagic fishes; recruitment processes, particularly factors affecting early life growth and survival; life history and migration studies; analytical approaches to fish demography.

Research Interests:

My research centers on the community and population ecology of aquatic organisms, with a special emphasis marine fishes. I am particularly interested in linkages between habitat selection, individual responses, and survival during early life stages. My work is both laboratory and field-based, and I typically use both quantitative and experimental approaches to elucidate the importance of biotic and abiotic factors that influence early life growth, condition, and survival. The scope of my research has expanded significantly in the last decade, and we are currently using a variety of natural markers to solve ecological problems. For example, otolith chemistry is being used to retrospectively determine the environmental histories of marine fishes. The premise of otolith chemistry is that certain elements or isotopes are incorporated into otoliths in proportion to their concentrations in the environment, and thus we use these elemental fingerprints to distinguish individuals from different environments or regions. Also, we are using dietary tracers (stable isotopes, fatty acids) to investigate marine food web structure since consumer tissues reflect the isotopic and fatty acid composition of prey in a predictable. These natural biomarkers provide time-integrated or long-term measures of diet, and both approaches afford information on source(s) of organic matter supporting local food webs as well as trophic relationships of associated consumers.

Courses Taught:

Undergraduate: Marine Ecology, Fisheries Techniques
Graduate: Current Concepts in Marine Biology and Ecology, Ecology of Coral Reef Fishes
 

Current and Recent Research Projects:

• Stock structure and mixing rates of Atlantic bluefin tuna: insights from otolith chemistry  read more

• Movement and stock structure of blue marlin in the Gulf of Mexico using pop up satellite tags  read more

• Early life history of billfishes in the Gulf of Mexico

• Assessement of bathymetric highs as habitat of newly settled red snapper

• Recruitment and patterns of habitat use by newly settled southern flounder

• Characterization of mid-shelf banks in the NW Gulf as essential habitat of reef fishes  read more

• Otolith chemistry of istiophorids in the western Atlantic

• Bioaccumulation of mercury in large pelagic fishes  read more

• Ecological significance of Sargassum to fisheries productivity  read more

• Origin and mixing rates of red drum in Texas determined by otolith chemical analysis

• Early life survival strategies and capabilities of hatchery and wild stocks

Rooker Lab

Richard Kraus, Ph.D. (Assistant Research Scientist)
Jessica Beck (Ph.D. candidate)
Joe Mikulas (M.S. student)
Ryan Schloesser (M.S. student)
Jeff Simms (M.S. student)
Josh Harper (M.S. student)

Former graduate students and post-docs

Bert Geary, M.S. (2000), Current position: Research Technician, Texas A&M University
 

Selected Publications