Bob Scheibling

PhD (McGill)
  • Teaching & Research
  • Students' Research Topics
  • Graduates' occupations
  • Publications
  • Links
  • Teaching & Research
    Benthic marine ecology, marine biology, invertebrate fisheries, aquaculture, subtidal ecosystems.

    esearch in my laboratory is directed towards understanding the biological interactions and physical processes that determine the structure and dynamics of benthic marine populations and communities. The work addresses fundamental issues in theoretical ecology as well as applied aspects of invertebrate fisheries and aquaculture. A major area of research has been the study of the rocky subtidal ecosystem off Nova Scotia, which alternates between two community states, kelp beds and coralline barrens, depending upon the abundance of grazing sea urchins. Using observational and experimental approaches, my students and I examine processes that regulate the dynamics of urchin populations, such as reproduction and spawning, larval dispersal and settlement, predation and disease. Many of these studies have direct application for the sea urchin fisheries and aquaculture. In recent years, we have witnessed a massive disruption of this ecosystem by two "alien" species. The first, an encrusting bryozoan (Membranipora membranacea), has defoliated kelp beds and thus facilitated the spread of the second alien, an invasive green alga (Codium fragile).

    Classes in which Bob normally teaches:

    Our research is currently focussed on interactions between these aliens and the native community, and on the impact of these invasions on the structure and function of the coastal ecosystem.

    We have also worked extensively on the wave-swept rocky shores, investigating physical and biological processes that determine the distribution and abundance of intertidal organisms. In particular, we are interested in the effects of recruitment variability, predation and wave disturbance on patch dynamics and intertidal community organization. Most recently, we have concentrated on the ecology of Codium, which is invading intertidal and shallow subtidal habitats with equal rapacity. I periodically water my roots in tropical marine ecology through various studies in the Caribbean, Australia, East Africa, and the Galapagos. For example, I have recently revisited the subject of my PhD research (a Caribbean seastar named Oreaster) in a project aimed at understanding the impact of declining population size on the reproductive potential of free-spawning marine invertebrates.

    I teach a course in Marine Biology on the coast of Kenya in the winter term as part of the Study in Africa Program, of which Dalhousie is a partner.

    Examples of Students' Research Topics

    Honors BSc Students

    • Laverne Walker, BSc 2001. Effect of Hurricane Lenny on coral reefs in St. Lucia, West Indies.
    • Tara Gibson, BSc 2001. Feeding in the tropical brittlestar Ophiocoma scalopendrina: Adaptive behaviour or just a lot of arm waving.
    • Mark Robinson, BSc 2000. Behaviour of settling larvae and early juveniles of the sea urchin Strongylocentrotus droebachiensis.
    • Chantale Begin, BSc 2000. Population dynamics of the invasive green alga Codium fragile spp tomentosoides in tidepools on a rocky shore.
    Graduate Students
    • Toby Balch, PhD 2000. Spatial and temporal patterns of settlement and recruitment of echinoderms in kelp beds and barrens.
    • Susanne Meidel PhD 1999. Reproductive ecology of the sea urchin Strongylocentrotus droebachiensis
    • Heather Hunt, PhD 1998. Structure and dynamics of intertidal mussel (Mytilus trossulus, M. edulis) assemblages.

      Some Graduates' Occupations

    • Toby Balch, PhD 2000. Scientist with consulting company (Dillon Consulting, Halifax).
    • Anna Metaxas, PhD 1994. Assistant Professor, Oceanography Dept, Dalhousie.
    • Myriam Barbeau, PhD 1994. Assistant Professor, Biology Dept, UNB Fredricton.
    • Ellen Pedersen, MSc 1991. Senior Instructor, Okanogan University College, B.C.
    • Chris Pearce, MSc 1990. Scientist with aquaculture company (Ross Island Sea Farms).
    • Todd Minchinton, MSc 1990. Assistant Professor, Univ. of Adelaide, Australia.
    • Joanne Jellett, PhD 1987. CEO of Jellett Biotech, Dartmouth.
    • Mike Hart, MSc 1987. Assistant Professor, Biology Dept., Dalhousie.
    • Stewart Johnson, MSc 1986. Scientist with National Research Council, Halifax.

    Selected Publications

    Scheibling, R.E. and B.G. Hatcher 2001. The ecology of Strongylocentrotus droebachiensis. In: The Biology and Ecology of Edible Sea Urchins (J.M. Lawrence, ed). Elsevier Sci. Press

    Hunt, H.L. and R.E. Scheibling 2001. Patch dynamics of mussels on rock shores: integrating process to understand pattern. Ecology (In press)

    Metaxas, A, Scheibling, R.E. and. C.M. Young 2001. Estimating fertilization success in marine benthic invertebrates: A case study with the tropical sea star Oreaster reticulatus. Mar. Ecol. Prog. Ser. (In press).

    Meidel, S.K. and R.E. Scheibling 2001. Variation in egg spawning among subpopulations of sea urchins (Strongylocentrotus droebachiensis): a theoretical approach. Mar. Ecol. Prog. Ser. 213: 97-110.

    Scheibling, R.E and S.X. Anthony. 2001. Feeding, growth and reproduction of sea urchins (Strongylocentrotus droebachiensis) on single and mixed diets of kelp (Laminaria spp.) and the invasive alga Codium fragile ssp. tomentosoides. Marine Biology (In press)

    Balch, T. and R.E. Scheibling 2000. Temporal and spatial variability in settlement and recruitment of echinoderms in kelp beds and barrens off Nova Scotia. Mar. Ecol. Prog. Series 205: 139-154.

    Scheibling, R.E. 2000. Species invasions and community change threaten the sea urchin fishery in Nova Scotia. L'atelier sur la coordination de la researche sur l'oursin vert au Canada Atlantique. Online

    Scheibling, R.E., A.W. Hennigar and T. Balch 1999. Destructive grazing, epiphytism, and disease: the dynamics of sea urchin-kelp interactions in Nova Scotia. Can. J. Fish. Aquat. Sci.56:2300-2314.

    Scheibling, R.E. and A.W. Hennigar 1997. Recurrent outbreaks of disease in sea urchins Strongylocentrotus droebachiensis along the Atlantic coast of Nova Scotia: Evidence for a link with large-scale meteorologic and oceanographic events. Mar. Ecol. Prog. Ser. 152: 155-165.

    Scheibling, R.E. 1996. The role of predation in regulating sea urchin populations in eastern Canada. Oceanologica Acta. 19: 421-430.