Dr. William B. Stickle, Jr.

Professor

Marine fauna are exposed to intensity gradients of environmental factors which limit their distribution and alter their capacity to adapt. Gradients of environmental factors vary on both a diurnal and seasonal basis. Environmental factors may be either natural (dissolved oxygen, salinity, temperature, UV-light), or anthropogenic (heavy metals, petroleum hydrocarbons, pesticides). Research in our laboratory is focused on gaining an understanding of how marine fauna adapt to intensity gradients of these factors.

We have recently utilized several sublethal stress indices or biomarkers to investigate the response of populations of species to intensity gradients of environmental factors. Techniques utilized include the determination of energy budgets through the Scope for Growth technique, Oxygen:Nitrogen ratios to determine the metabolic substrate catabolized, RNA:DNA ratios and heat shock protein induction (Hsp) to determine the physiological status of animals. Specific biomarkers utilized in our study of anthropogenic factors include the determination of the degree of imposex of gastropods exposed to tributyltin and induction of cytochrome P-450 enzymes in killifish upon exposure to petroleum hydrocarbons. We have also discovered cryptic species of gastropods and sea stars through population genetic studies in collaboration with Dr. David Foltz.

Relevant to the biota of the Gulf of Mexico, Dr. Strickle has published the following:

Liu, L. L., D. W. Foltz, and W. B. Stickle. 1991. Genetic population structure of the southern oyster drill Stramonita (=Thais) haemostoma [sic]. Marine Biology 111(1): 71–79.