Benthic ecology; biomechanics of burrowing; biological-physical interactions; functional morphology and physiology of invertebrates...
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.
Having just joined the DISL faculty this fall, I 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.
Recent Publications (*undergraduate student I mentored)
Law, C.J.*, K.M. Dorgan, and G.W. Rouse. In review. Relating divergence in musculature within Opheliidae (Annelida) with different burrowing behaviors. Journal of Morphology.
Dorgan, K.M., C.J. Law*, and G.W. Rouse. 2013. Meandering worms: Mechanics of undulatory burrowing in muds. Proceedings of the Royal Society B 280(1757): 20122948; 1471-2954.
Law, C.J.*, K.M. Dorgan, and G.W. Rouse. 2013. Validation of three sympatric Thoracophelia species (Annelida: Opheliidae) from Dillon Beach, CA using mitochondrial and nuclear DNA sequence data. Zootaxa 3608 (1): 067–074.
Dorgan, K.M., S. Lefebvre, J.H. Stillman, M.A.R. Koehl. 2011. Energetics of burrowing by the cirratulid polychaete, Cirriformia moorei. Journal of Experimental Biology 214: 2202-2214.
Denny, M., K.M. Dorgan, D. Evangelista, A. Hettinger, J. Leichter, W. Ruder, I. Tuval. 2011. Anchor ice and benthic disturbance in shallow Antarctic waters: Interspecific variation in initiation and propagation of ice crystals. Biological Bulletin 221(2). **Editor’s pick and cover image
Johnson, B.D., M. Barry, B.P. Boudreau, P.A. Jumars, K.M. Dorgan. 2011. In Situ Tensile Fracture Toughness of Surficial Cohesive Marine Sediments. Geo-Marine Letters. DOI: 10.1007/s00367-011-0243-1.
Murphy, E.A.K.*, K.M. Dorgan. 2011. Burrow extension with a proboscis: Mechanics of burrowing by the glycerid, Hemipodus simplex. Journal of Experimental Biology 214: 1017-1027.
Che, J.*, K.M. Dorgan. 2010. Mechanics and kinematics of backward burrowing by the polychaete, Cirriformia moorei. Journal of Experimental Biology 213: 4272-4277.
Dorgan, K.M. 2010. Environmental constraints on the mechanics of crawling and burrowing using hydrostatic skeletons. Journal of Experimental Mechanics 50(9): 1373-1381. DOI: 10.1007/s11340-010-9399-2
Che, J.* and K.M. Dorgan. 2010. It’s tough to be small: Dependence of burrowing kinematics on body size. Journal of Experimental Biology 213: 1241-1250.
**featured article in “Inside JEB”
Dorgan, K.M., S.R. Arwade, and P.A. Jumars. 2008. Worms as wedges: Effects of the mechanical properties of the medium on burrowing behavior. Journal of Marine Research 66(2): 219-254.
Dorgan, K.M., S.R. Arwade, and P.A. Jumars. 2007. Burrowing in muddy sediments by crack propagation: forces and kinematics. Journal of Experimental Biology 210: 4198-4212. **F-1000recommended (Summers A: 2008. F1000.com/1116373)
Jumars, P.A., K.M. Dorgan, L.M. Mayer, B.P. Boudreau and B.D. Johnson. 2007. Physical constraints on infaunal lifestyles: May the persistent and strong forces be with you. In: W. Miller, III, Ed. Trace Fossils: Concepts, Problems, Prospects. Elsevier, pp. 442-457.
Dorgan, K.M., P.A. Jumars, B.P. Boudreau and B.D. Johnson. 2006. Macrofaunal burrowing: The medium is the message. Oceanography and Marine Biology: An Annual Review 44: 85-121.
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. 2005. Bubble growth and rise in soft sediments. Geology 33 (6): 517-520.
Dorgan, K.M., P.A. Jumars, B. Johnson, B.P. Boudreau, and E. Landis. 2005. Burrow extension by crack propagation. Nature 433: 475. **ASLO Lindeman award recipient
Dorgan, K.M., A. Valdes, and T.M. Gosliner. 2002. Phylogenetic systematics of the genus Platydoris (Mollusca, Nudibranchia, Doridoidea) with descriptions of six new species. Zoologica Scripta 31: 271-319.