Luke MillerPostdoctoral ResearcherPh.D., Stanford University
l.miller at neu.edu |
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BackgroundMy research has focused on the interplay between organisms and the abiotic stresses imposed by their environment. I have used the rocky intertidal zone as a testbed for hypotheses about the roles of organismal morphology, behavior, and physiology in ameliorating the extreme physical and physiological stresses created by breaking waves and extreme temperature regimes found on rocky shores. In a habitat where water velocities can often exceed 70 mph (>30m/s) and temperatures can reach well above 37°C (~100°F), what characteristics of organisms allow them to survive and flourish, making rocky shores some of the most diverse and productive habitats on earth? How might these organismal traits then affect the ecological interactions that occur within and among species on the shoreline?
Snail talesThe central theme of my thesis research was exploring how intertidal snails and limpets deal with extreme high temperatures during low tide periods. The gastropods living in the intertidal zone are all marine organisms that need to be wetted by seawater on occassion in order to survive, yet they will often be exposed to the air for more than half the day (or even multiple days or weeks). During these aerial exposure periods, the environment may drive their body temperatures well beyond the typical ocean temperatures they experience, and these snails must be capable of withstanding these huge swings in body temperature. I have constructed computer heat-budget models for littorine snails that allow me to manipulate various morphological and behavioral characteristics to gauge the effect on body temperature. These computer models are combined with experiments on live animals in the field and in the laboratory to hopefully give us a better understanding of the role various animal characteristics play in avoiding heat-induced stress or mortality. In addition to work on the littorine snails of the west coast of North America, I have carried out physiological studies on the limpet Lottia gigantea, a major competitor for primary space in the intertidal zone of California. Again, with an eye towards combining model data and empirical data from live animals, I collected physiological performance data for limpets stressed in a controlled laboratory setting designed to mimic realistic stressful field conditions. When we attempt to accurately recreate field stress events, it becomes apparent that the upper limits of the tolerances of these organisms are often quite close to the conditions created during hot periods on the shore. As a result, abiotic factors can potentially influence the distributions of a species, which has cascading effects on the remainder of the intertidal community, both on a small scale and over larger geographical scales.
Publications - (reprints happily provided upon request)
Miller, L. P., Harley, C. D. G. & M. W. Denny. 2009. The role of temperature and desiccation stress in limiting the local-scale distribution of the owl limpet, Lottia gigantea. Functional Ecology, 23(4): 756-767.
Denny, M. W., Hunt, L. J. H., Miller, L. P. & C. D. G. Harley. 2009 On the prediction of extreme ecological events. Ecological Monographs 79(3): 397-421
Harley, C. D. G., Denny, M. W., Mach, K. J. & L. P. Miller. 2009. Thermal stress and morphological adaptations in limpets. Functional Ecology, 23, no. 2, pgs 292-301
Dong, Y., Miller, L. P., Sanders, J. G. & G. N. Somero. 2008. Heat-shock protein 70 (Hsp70) expression in four limpets of the genus Lottia: interspecific variation in constitutive and inducible synthesis correlates with in situ exposure to heat stress. Biological Bulletin, 215, pgs. 173-181
Miller, L. P. 2007. Feeding in extreme flows: behavior compensates for mechanical constraints in barnacle cirri. Marine Ecology Progress Series, 349, pgs. 227-234
Miller, L. P. & B. Gaylord. 2007. Barriers to flow: the effects of experimental cage structures on water velocities in high-energy subtidal and intertidal environments. Journal of Experimental Marine Biology and Ecology, 344, pgs. 215-228
Miller, L. P., O'Donnell, M. J. & K. J. Mach. 2007. Dislodged but not dead: survivorship of a high intertidal snail following wave dislodgement. Journal of the Marine Biological Association of the United Kingdom, 87, pgs. 735-739
Denny, M. & Miller, L. 2006. Jet propulsion in the cold: mechanics of swimming in the Antarctic scallop Adamussium colbecki. Journal of Experimental Biology, 209, pgs. 4503-4514.
Denny, M. W., Miller, L. P. & C. D. G. Harley 2006. Thermal stress on intertidal limpets: long-term hindcasts and lethal limits. Journal of Experimental Biology, 209, pgs. 2420-2431.
Denny, M. W., Miller, L. P., Stokes, M. D., Hunt, L. J. H. & B. S. T. Helmuth. 2003. Extreme water velocities: Topographical amplification of wave-induced flow in the surf zone of rocky shores. Limnology and Oceanography, 48, pgs. 1-8.
PhD Thesis :
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