Biology

REU: Aquatic Chemical Ecology at Georgia Tech



Area 1. Biological and geochemical transformations of chemicals in aquatic ecosystems.

Nutrients, allelopathic or toxic chemicals, and metabolic by-products can affect organisms in a variety of ways, from inhibiting or stimulating growth , to inducing aggregations or mediating habitat choice. The production and fate of these chemicals is often influenced by geochemical and biological processes in water columns, in sediments or in the guts of animals. Many of these transformations are mediated by microbes. This area includes determining the mechanisms, rates, and impacts of these processes, as well as developing methods to study these transformations (e.g., in situ analysis of microbial populations, analytical chemical methods, etc). Typical research questions include:

  • 1) What is the role of microbial endosymbionts in allowing organisms to digest harmful secondary metabolites or turn organic matter into body mass?
  • 2) What is the role of syntrophic associations of microbes in material and energy cycling?
  • 3) How do competing phytoplankton and marine bacteria degrade red tide toxins and avoid allelopathic effects?
  • 4) How have bacteria evolved to metabolize anthropogenic chemicals that structurally resemble natural products?
  • 5) How do analytical or molecular techniques contribute to our understanding of material and energy cycling?
  • 6) What can the study of chemical tracers tell us about climate history and climate change?

Faculty mentors in this area: Cobb, (Fernandez), (Kubanek), Loeffler, Montoya, Taillefert
(bracketed individuals represent secondary roles in this area)


Area 2. Sensory biology and ecology of aquatic chemical communication.

Chemical signals are used by animals to find prey, escape predators, locate/choose mates, and determine suitable habitats. The ability of animals to successfully use chemical signals determines their fate and the rates of critical ecological interactions. This area includes determining how chemical cues are transmitted in aquatic habitats and analyzing behavioral and sensory mechanisms by which animals detect and respond to these signals. Typical questions include:

  • 1) How do chemical cues affect olfactory-mediated navigation to prey or mates?
  • 2) How do these signals allow individuals to locate, identify and choose mates, and promote or maintain reproductive isolation?
  • 3) How do physical forces and fluid dynamics regulate detection of chemical signals and animal behavior?
  • 4) What is the effect of combined attractant and deterrent odors on zooplankton aggregation in thin layer oceanic structures?
  • 5) How are neurotransmitters used by chemosensory organisms in the process of learning?
  • 6) Can a robotic mimic reproduce the phenomenal turbulent chemical plume tracking performance of blue crabs?

Faculty mentors in this area: (Hay), Lu, (Snell), Webster, Weissburg, Yen
(bracketed individuals represent secondary roles in this area)


Area 3. Ecological roles and consequences of chemicals in aquatic environments.

Chemical signals influence the behavior of individuals and their ecological interactions with predators, prey, competitors, hosts, and mates. Thus, chemical signals have significant impacts on population and community structure when their effects are extrapolated over a large number of individual interactions. This area includes examining the role of defensive compounds and signal molecules in population regulation and community structure. In order to understand these roles, we must know the identity of these compounds and how they are presented in natural settings. Typical questions include:

  • 1) What types of microbial, algal, or animal exudates regulate prey/host location, predator detection and deterrence, and competitive interactions?
  • 2) What are the molecular structures of chemical cues in aquatic environments and how are they localized within tissues, released onto biological surfaces or into seawater?
  • 3) Do environmentally-induced changes in the transport of chemical signals influence patterns of predation or mating observed in nature?
  • 4) What is the role of chemical cues in initiating, maintaining, or terminating phytoplankton blooms?
  • 5) How do chemically-mediated interactions affect the success or failure of biological invasions?
  • 6) How can knowledge of chemically-mediated interactions aid in managing/restoring threatened habitats (e.g., coral reefs)?

Faculty mentors in this area: Fernandez, Hay, Kubanek, (Montoya), Snell, (Weissburg)
(bracketed individuals represent secondary roles in this area)