The great American marine ecologist Robert T. (Bob) Paine passed away in Seattle on June 13, 2016. During the last half century, Bob introduced some of the most important conceptual advances in community ecology, perhaps none more influential than that of the keystone species. A keystone species is one that has a disproportionately large effect on its surrounding community. Such a species plays a critical role in maintaining the community’s structure, affecting many other organisms, and helping to determine the types and numbers of various other species found in that community.

Greene, C.H. 2016. Wading in the footsteps of an ecological giant. Oceanography 29(2):5–6, https://doi.org/10.5670/oceanog.2016.25.

Cavole, L.M., A.M. Demko, R.E. Diner, A. Giddings, I. Koester, C.M.L.S. Pagniello, M.-L. Paulsen, A. Ramirez-Valdez, S.M. Schwenck, N.K. Yen, and others. 2016. Biological impacts of the 2013–2015 warm-water anomaly in the Northeast Pacific: Winners, losers, and the future. Oceanography 29(2):273–285, https://doi.org/10.5670/oceanog.2016.32.

Hairston, N.G., F.E. Smith, and L.B. Slobodkin. 1960. Community structure, population control, and competition. The American Naturalist 94(879):421–425. 

Paine, R.T. 1966. Food web complexity and species diversity. The American Naturalist 100(910):65–75.

Pfister, C.A., R.T. Paine, and J.T. Wooten. 2016. The iconic keystone predator has a pathogen. Frontiers in Ecology and the Environment 14(5):285–286, https://doi.org/10.1002/fee.1292.

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