Dr. Kelly Dorgan

Dr. Kelly Dorgan

Senior Marine Scientist I

Assistant Professor of Marine Sciences, University of South Alabama

Bio

University of Maine, 2007

I am interested in how worms and other benthic organisms interact with their environments. Burrowing animals are numerically abundant and ecologically important, both in trophic dynamics and as ecosystem engineers, dramatically altering their physical and chemical environments. Because the opacity of sediments (muds and sands) limits direct observation, I use tools from engineering and physics to develop new methods in order to integrate theory and experiments. Muds behave elastically due to the gel-like organic material that fills spaces between the grains, and I have shown that worms extend burrows by fracturing this organic matrix. Sands are granular materials with very different mechanical responses to burrowers than muds. Even within muds, burrowers exhibit different behaviors based on body size and sediment properties. My research therefore focuses on the mechanical properties of sediments as well as the diverse morphologies and behaviors of burrowing animals.

I joined the faculty at Dauphin Island Sea Lab in the fall of 2013 and am enjoying exploring burrowing fauna and their environments in Mobile Bay and the Gulf of Mexico. I am particularly interested in how benthic microalgae and bacteria alter sediment habitats for larger organisms and in developing new methods to measure sediment properties on the small scales of burrowing animals. Potential projects in my lab could include sub-lethal effects of hypoxia and pollutants (such as oil) on worm behaviors and sediment structure, interactions between bottom boundary layer flow and sediment structure or seagrass beds, and how burrowing behaviors mix sediments, resulting in bioturbation.

Research Interest

I study how worms and other benthic organisms interact with their environments. Burrowing animals are ecologically important, both in trophic dynamics and as ecosystem engineers, dramatically altering their physical and chemical environments. My research focuses on the diverse morphologies and behaviors of burrowing animals, the biomechanics of burrowing in muds and sands, and the mechanical properties of sediments.

Because the opacity of sediments (mud and sand) limits direct observation, I use tools from engineering and physics to develop new methods and integrate theory, modeling and experiments. Marine muds behave elastically due to the gel-like organic material that fills spaces between the grains, and I have shown that worms extend burrows by fracturing this organic matrix. Sands are non-cohesive granular materials that differ mechanically from cohesive muds. Burrowers exhibit different behaviors based on body size and sediment properties. These differences have implications for species distributions and interactions.

I will be joining the DISL faculty this fall, and am looking forward to exploring burrowing fauna and their environments in Mobile Bay and the Gulf of Mexico. I am particularly interested in developing new methods to measure sediment properties and characterize habitats to address questions such as how benthic microalgae and bacteria alter sediments as habitats for larger organisms. Potential projects in my lab could include sub-lethal effects of hypoxia and pollutants (such as oil) on worm behaviors and sediment structure, interactions between bottom boundary layer flow and sediment structure or seagrass beds, and how burrowing behaviors mix sediments, resulting in bioturbation.

Projects

Publications

  • 2014 - In Press

    Jumars, P.A., *K.M. Dorgan*, S.M. Lindsay.. Diet of worms emended: An update of Polychaete feeding guilds.

  • 2014

    Francoeur, A.A.*, *K.M. Dorgan*.. Burrowing behavior in mud and sand of morphologically divergent polychaete species (Annelida: Orbiniidae).

  • Law, C.J., K.M. Dorgan, and G.W. Rouse.. Relating divergence in polychaete musculature to different burrowing behaviors: a study using Opheliidae (Annelida).

  • 2013

    Dorgan, K.M., C.J. Law, and G.W. Rouse.. Meandering worms: Mechanics of undulatory burrowing in muds.

  • Law, C.J., K.M. Dorgan, and G.W. Rouse.. Validation of three sympatric Thoracophelia species (Annelida: Opheliidae) from Dillon Beach, CA using mitochondrial and nuclear DNA sequence data.

  • 2011

    Dorgan, K.M., S. Lefebvre, J.H. Stillman, M.A.R. Koehl.. Energetics of burrowing by the cirratulid polychaete, Cirriformia moorei.

  • 2010

    Dorgan, K.M.. Environmental constraints on the mechanics of crawling and burrowing using hydrostatic skeletons.

  • 2008

    Dorgan, K.M., S.R. Arwade, and P.A. Jumars.. Worms as wedges: Effects of the mechanical properties of the medium on burrowing behavior.

  • 2007

    Dorgan, K.M., S.R. Arwade, and P.A. Jumars.. Burrowing in muddy sediments by crack propagation: forces and kinematics.

  • 2006

    Dorgan, K.M., P.A. Jumars, B.P. Boudreau and B.D. Johnson.. Macrofaunal burrowing: The medium is the message.

  • 2005

    Boudreau, B.P., Algar, C., Johnson, B., Croudace, I., Reed, A., Dorgan, K.M., Jumars, P.A., Grader, A.S., Gardiner, B.S., and Y. Furukawa.. Bubble growth and rise in soft sediments.

  • Dorgan, K.M., P.A. Jumars, B. Johnson, B.P. Boudreau, and E. Landis.. Burrow extension by crack propagation.

  • 2002

    Dorgan, K.M., A. Valdes, and T.M. Gosliner.. Phylogenetic systematics of the genus Platydoris (Mollusca, Nudibranchia, Doridoidea) with descriptions of six new species.

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