Geographic Range Limits

What environmental and biological factors set geographic range limits and to what extent can these boundaries be overcome through adaptation and/or phenotypic plasticity? The geographic distributions of many coastal species have changed profoundly in recent decades. In the NW Atlantic, we conducted larval rearing experiments and field studies to predict the recent poleward range extension of fiddler crabs into salt marshes in northern New England. In the NE Pacific, we have documented an unprecedented number of recent range extensions of historically southern taxa into northern California. We are currently studying the ecological and evolutionary processes that facilitate or impede the success of such range expansions with the goal of predicting future shifts in community composition in an era of accelerating climatic change.

Selected Publications

Sanford, E., J.L. Sones, M. García-Reyes, J.H.R. Goddard, and J.L. Largier. 2019. Widespread shifts in the coastal biota of northern California during the 2014–2016 marine heatwaves.  Scientific Reports, doi.org/10.1038/s41598-019-40784-3

Sanford, E.  2013.  The Biogeography of Marine Communities.  Ch. 7 in: M.D. Bertness, J. Bruno, B.R. Silliman, and J.J. Stachowicz (eds), Marine Community Ecology and Conservation. Sinauer Press, Sunderland, MA.

Dawson, M.N., R.K. Grosberg, Y.E. Stuart, and E. Sanford.  2010.  Population genetic analysis of a recent range expansion: mechanisms regulating the poleward range limit in the volcano barnacle Tetraclita rubescens.  Molecular Ecology 19: 1585–1605.

Sanford, E. and D.S. Swezey. 2008. Response of predatory snails to a novel prey following the geographic range expansion of an intertidal barnacle. Journal of Experimental Marine Biology and Ecology 354: 220-230.

Sanford, E., S.B. Holzman, R.A. Haney, D.M. Rand, and M.D. Bertness.  2006.  Larval tolerance, gene flow, and the northern geographic range limit of fiddler crabs.  Ecology 87: 2882–2894.