Larry G Harris, Ph.D.

Larry G Harris, Ph.D.

Professor and Chair of the Department of Biological Sciences

I was trained as an invertebrate zoologist with strong interests in life histories, behavior, and defensive strategies utilized between members of predator-prey associations. My teaching and research focus primarily on marine species and communities and while most of my studies are done in the Gulf of Maine, I have experience in a wide diversity of habitats (Panama, Chile and Indonesia in 2005). My research is most accurately described as quantitative and manipulative natural history. The focus is on organisms and how they are adapted to their environments. This would be in contrast to a more theoretical approach that places primary emphasis on testing general models. Both are important - I just happen to like living organisms first.


My primary teaching responsibilities include Zoology 503 - Marine Biology; Zoology 628 - Ecology and Evolution of Marine Invertebrates; Tech 797 - Ocean Projects (a year-long projects course for seniors in biology and ocean engineering); Zoology 796 - Invasive Species Ecology and Management (this course is being developed at present). My courses all have laboratories that are hands-on and emphasize living material and field trips. I also sponsor graduate seminars and supervise undergraduate and graduate students in research.


My research and that of the undergraduate and graduate students that I supervise focuses on three major areas of interest.

The role of predation in benthic communities

The interest in predation has included the study of specific predator-prey associations, particularly with nudibranchs and their cnidarian prey and also the role of predation in benthic community succession.

Sea urchin ecology and aquaculture

A population explosion of the green sea urchin Strongylocentrotus droebachiensis in the Gulf of Maine and its subsequent decline due to overfishing has resulted in a number of studies of sea urchin ecology, life history and recruitment patterns and efforts to promote an urchin aquaculture industry. Included in the effort to promote the fishery has been the development of a sea urchin hatchery that is currently operating in collaboration with a former urchin harvester.

The ecology of invasive species

Major changes have occurred in the benthic communities of the Gulf of Maine, including the successful establishment of a series of introduced species that have significantly altered community structure and composition. Studies of the impact of several of these new species are under way.

I actively involve undergraduate students in all phases of my research program and encourage personal initiative to undertake independent studies when there is the desire to do so.

I have been actively involved in supervising graduate students in both Masters and PhD programs (45 graduated and 3 currently working in my lab). My philosophy of graduate education is one of encouraging independent investigation - my graduate students must select their own thesis problem as long as it is within my area of expertise and interest and my interests are rather broad. Students who work with me must do a Masters on the way to a doctorate or they may stop with the Masters.

Selected Publications

  • Harris, L.G. and A.C. Mathieson. 2000. Patterns of range expansion, niche shift and predator acquisition in Codium fragile ssp. tomentosoides and Membranipora membranacea in the Gulf of Maine. In Pederson, J. (ed.), Proc. Natl. Conf. on Mar. Bioinvasions. M.I.T. Press, Cambridge, pp. 46-56.
  • Lambert, D. and L.G. Harris. 2000. Larval settlement of the green sea urchin, Strongylocentrotus droebachiensis, in the southern Gulf of Maine. Invert. Biol. 119:403-409.
  • Tyrrell, M. and L.G. Harris. 2000. Potential impact of the introduced Asian shore crab, Hemigrapsus sanguineus, in northern New England: Diet, feeding preferences, and overlap with the green crab, Carcinus maenus. In Pederson, J. (ed.), Proc. Natl. Conf. on Bioinvasions. M.I.T. Press, Cambridge, pp. 208-220.
  • Harris, L.G. and M. Tyrrell. 2001. Changing community states in the Gulf of Maine: Synergism between invaders, overfishing and climate change. Biol. Invasions 3:9-21.
  • Harris, L.G., M.C. Tyrrell, C.T. Williams, C.G. Sisson, S. Chavanich, and C.M. Chester. 2001. Declining sea urchin recruitment in the Gulf of Maine: Is overharvesting to blame? In Barker, M. (ed.), Proc. 10th International Echinoderm Conf. A.A. Balkema, Rotterdam, pp. 439-444.
  • Harris, L.G., P. Madigan, and K. Waters. 2003. A hatchery system for green sea urchin aquaculture in the Gulf of Maine. World Aquaculture 34:32-38 & 71.
  • Harris, L.G., P.A. Madigan, and R.L. Toppin. 2004. Test of a suspended recruitment and juvenile grow out system for the sea urchin Strongylocentrotus droebachiensis in the Gulf of Maine. In Heinzeller, T. and J.H. Nebelsick (eds.), Proceedings of the 11th International Echinoderm Conference, Munich, Germany. A.A. Balkema, New York, pp. 277-282.
  • Harris, L.G. and A.C. Jones. 2005. Temperature, herbivory and epibiont acquisition as factors controlling the distribution and ecological role of an invasive seaweed. Biological Invasions (in press).
Larry Harris
Rudman Hall
Durham, NH 03824