David S. Johnson

I am a marine ecologist who studies how global changes (sea-level rise, climate change, nutrient enrichment, invasive species) affect coastal ecosystems. With 7 billion people on the planet and a predicted growth of 9 billion by the time I’m thinking about retirement (2050), our impact on the planet will likely continue to grow. I am interested in how ecosystems will be altered as viewed through the lens of animal and plant responses to global changes. For instance, how does increasing sea-level affect trophic interactions in intertidal communities? In this way, I can address questions of how global changes can affect top-down (consumer) and bottom-up (resource) control of communities, food-web structure, biodiversity and ecosystem functioning, and the role of species traits (behavior, morphology) in structuring communities.  Most, but not all, of my research is focused consumer-consumed interactions.

Science Communcation

Science communication, beyond publishing in peer-reviewed journals, is a critical component of my science. Much of my communication has been via newspaper articles and essays. Some of this stems from my being fascinated with the natural world and wanting to share those experiences with others. It also stems from my desire to take science from the dusty e-files of arcane journals and make that information available to a broader audience. In that vein, you can follow my blog and follow me on Twitter @DavidSamJohnson.

Current Projects

The TIDE Project: an ecosystem-level nutrient enrichment experiment to examine the effect of nutrient run-off on marsh ecosystems. 

Crab Trax: I am monitoring the northward migration of crabs into the Gulf of Maine as associated with climate change [see Johnson 2014 and Johnson 2015 below]

Publications

Johnson, D.S. 2015. The savory swimmer swims north: A northern range extension for the blue crab, Callinectes sapdius? Journal of Crustacean Biology

Johnson, D.S. 2014. Fiddler on the Roof: A northern range extension for the marsh fiddler crab Uca pugnax. Journal of Crustacean Biology 34:671-673.

Johnson, D.S. 2014. Making waves about spreading weeds – A response. Science 344:1236

Johnson, D.S. 2014. Weeds making waves. Essay. Science 344:255

Johnson, D.S. and M. I. Short.  2013.  Chronic nutrient enrichment increases the density and biomass of the eastern mudsnail, Nassarius obsoletus.  Estuaries and Coasts 36: 28-35

Pascal, P-Y, J.W. Fleeger, H.T.S. Boshker, H. Mitwally, and D.S. Johnson. 2013. Chronic nutrient-enrichment influence on mudflat food web in a New England (USA) estuary.  Marine Ecology Progress Series.  474:27-41

Fagherazzi S., D.M. FitzGerald D.M., R.W Fulweiler, Z. Hughes, P.L. Wiberg, K.J. McGlathery, J.T. Morris, T.J. Tolhurst, L.A. Deegan, and D.S. Johnson. 2013. Ecogeomorphology of Salt Marshes.  In:  John F. Shroder (ed.) Treatise on Geomorphology, Volume 12: 180-200.

Fagherazzi S., D.M. FitzGerald D.M., R.W Fulweiler, Z. Hughes, P.L. Wiberg, K.J. McGlathery, J.T. Morris, T.J. Tolhurst, L.A. Deegan, and D.S. Johnson. 2013. Ecogeomorphology of Tidal Flats.  In:  John F. Shroder (ed.) Treatise on Geomorphology, Volume 12: 201-220.

Deegan, L.A., D.S. Johnson, R.S. Warren, B.J. Peterson, J.W. Fleeger, S. Fagherazzi, and W. Wollheim.  2012. Coastal nutrient enrichment as a driver of salt marsh loss.  Nature 490: 388-392.

            -Recommended as a ‘must read’ in the Faculty of 1000

            -Featured in many popular press outlets including NPR, Boston Globe (DSJ quotation), Cape Cod Times (DSJ quotation), and CBC

Galván, K., J.W. Fleeger, B.J. Peterson, D. Drake, L.A. Deegan, and D.S. Johnson. 

2011. Natural abundance stable isotopes and dual isotope tracer additions help to resolve resources supporting a saltmarsh food web.  Journal of Experimental Marine Biology and Ecology 410: 1-11.

Johnson, D.S.  2011.  High-marsh invertebrate communities are susceptible to eutrophication.  Marine Ecology Progress Series 438:143-152.

Fleeger, J.W., D.S. Johnson, K.R. Carman, P.B. Weisenhorn, A. Gabriele, D. Thistle, and J.P. Barry. 2010. The response of nematodes to deep-sea CO2 sequestration:  A quantile regression approach.  Deep Sea Research I 57:696-707.

Johnson, D.S., and J.W. Fleeger.  2009.  The effect of large-scale nutrient enrichment and predator reduction on macroinfauna in a Massachusetts salt marsh:  a four-year study.  Journal of Experimental Marine Biology and Ecology 373:  35-44.

Johnson, D.S., J.W. Fleeger, and L.A. Deegan.  2009.   Large-scale manipulations reveal top-down and bottom-up controls interact to alter habitat utilization by saltmarsh fauna.  Marine Ecology Progress Series 377: 33-41.

Johnson, D.S., and B. J. Jessen.  2008.  Do spur-throated grasshoppers, Melanoplus spp. (Orthoptera: Acrididae), exert top-down control on smooth cordgrass Spartina alterniflora in northern New England?  Estuaries and Coasts 31:912-919.

Fleeger, J.W., D.S. Johnson, K. A. Galván, and L. A. Deegan.  2008. Top-down and bottom-up control of infauna varies across the saltmarsh landscape.  Journal of Experimental Marine Biology and Ecology 357:  20-34.

Deegan, L.A., J.L. Bowen, D. Drake, J.W. Fleeger, C.T. Friedrichs, K.A. Galván, J.E. Hobbie, C. Hopkinson, J.M. Johnson, D.S. Johnson, L.E. Lemay, E. Miller, B.J. Peterson, C. Picard, S. Sheldon, J. Vallino, R.S. Warren. 2007. Susceptibility of salt marshes to nutrient enrichment and predator removal.  Ecological Applications 17(5):S42-S63. 

Johnson, D.S., J.W. Fleeger, K.A. Galván, and E.B. Moser.  2007.  Worm holes and their space-time continuum: Spatial and temporal variability of macroinfaunal annelids in a northern New England salt marsh.  Estuaries and Coasts 30 (2): 226-237.