Staff Profile
Photo for Greg Ruiz


Greg is a marine ecologist with active research interests in invasion biology, biogeography, and ecology in coastal marine ecosystems.  He heads a research group of ~ 40 full-time biologists, based at the Smithsonian Environmental Research Center (SERC) laboratories, located on Chesapeake Bay and San Francisco Bay. Most of his research explores the patterns, mechanisms, and consequences of marine invasions at a multiple spatial and temporal scales. He conducts extensive comparative measurements and experiments among estuaries along the Pacific and Atlantic coasts for North America.  A Senior Scientist at SERC for over 25 years, Greg also is a Research Professor and founding co-director of the Aquatic BioInvasion Research and Policy Institute at Portland State University.  Greg has published over 140 scientific articles as author or coauthor, focusing primarily on marine invasion ecology and management. He began his career in California and has broad interests in marine biology and dynamics of coastal ecosystems. Greg holds a Ph.D. in zoology from University of California, Berkeley and a B.A. in aquatic biology from the University of California, Santa Barbara.  For additional information visit SERC’s Marine Invasion Research Laboratory website at
Selected Publications (of 140)

Ruiz, GM, Fofonoff PW, Steves BP, Carlton JT. 2015. Invasion history and vector dynamics in coastal marine ecosystems: a North American perspective.  Aquatic Ecosystem Health and Management (in press).

Miller AW, Ruiz GM. 2014. Artic shipping and marine invaders. Nature Climate Change 4:413-416.

Freestone AL, GM, Ruiz, & ME Torchin. 2013. Stronger biotic resistance in tropics: Effects of predation on invasion dynamics across latitude. Ecology 94:1370–1377.

Ruiz GM, Fofonoff PW, Ashton G, Minton MS, Miller AW. 2013. Geographic variation in marine invasions among large estuaries: Effects of ships and time. Ecological Applications 23:311-320.

deRivera CE, Grosholz ED, Ruiz GM. 2011. Multiple and long-term impacts of an introduced marine predator. Mar Ecol Prog Ser 429:145-155 doi:10.3354/meps09101

Ruiz GM, Fofonoff PW, Steves B, Foss SF, Shiba SN. 2011. Marine invasion history and vector analysis of California: A hotspot for western North America. Diversity and Distributions 17:362-373.

Blakeslee AMH, Altman I, Miller AW, Byers JE, Hamer CE, Ruiz GM. 2012. Parasites and invasions: a biogeographic examination of parasites and hosts in native and introduced ranges. J. Biogeography 39:609-622.

deRivera CE, Ruiz GM, Hines AJ, Jivoff P. 2005. Biotic resistance to invasion: native crab predation limits the abundance and geographic distribution of an introduced crab. Ecology 86:3364-3376.

Ruiz GM, Rawlings TK, Dobbs FC, Drake LA, Mullady T, Huq A, Colwell RR.  2000.  Worldwide transfer of microorganisms by ships. Nature 408: 49-50.

Ruiz GM, Fofonoff PW, Carlton JT, Wonham MJ, Hines AH. 2000. Invasions of Coastal Marine Communities in North America: Apparent Patterns, Processes, and Biases. Annual Review of Ecology and Systematics 31: 481-531.

Ruiz GM, P Fofonoff, AH Hines, & ED Grosholz.  1999.  Nonindigenous species as stressors in estuarine and marine communities:  Assessing impacts and interactions.  Limnol. Oceanogr. 44:950-972.


  • Jimenez, Haizea and Ruiz, Gregory M. (2016). Contribution of non-native species to soft-sediment marine community structure of San Francisco Bay, California. Biological Invasions, 18 (7) , 2007-2016.
  • MacIsaac, Hugh J., De Roy, Emma M., Leung, Brian, Grgicak-Mannion, Alice and Ruiz, Gregory M. (2016). Possible Ballast Water Transfer of Lionfish to the Eastern Pacific Ocean. PloS One, 11 (11) , 1-12.
  • Moser, Cameron S., Wier, Timothy P., Grant, Jonathan F., First, Matthew R., Tamburri, Mario N., Ruiz, Gregory M., Miller, A. Whitman and Drake, Lisa A. (2016). Quantifying the total wetted surface area of the world fleet: a first step in determining the potential extent of ships’ biofouling. Biological Invasions, 18 (1) , 265-277.
  • Noble, Monaca, Ruiz, Gregory M. and Murphy, Kathleen R. (2016). Chemical Assessment of Ballast Water Exchange Compliance: Implementation in North America and New Zealand. Frontiers in Marine Science, , 66.
  • Pagenkopp Lohan, K. M., Fleischer, Robert C., Carney, K. J., Holzer, Kimberly K. and Ruiz, Gregory M. (2016). Amplicon-Based Pyrosequencing Reveals High Diversity of Protistan Parasites in Ships' Ballast Water: Implications for Biogeography and Infectious Diseases. Microbial ecology, 71 (3) , 530-542.
  • Sheets, Elizabeth A., Cohen, C. S., Ruiz, Gregory M. and da Rocha, Rosana M. (2016). Investigating the widespread introduction of a tropical marine fouling species. Ecology and Evolution, 6 (8) , 2453-2471.
  • Simkanin, Christina, Fofonoff, Paul W., Larson, Kristen J., Lambert, Gretchen, Dijkstra, Jennifer A. and Ruiz, Gregory M. (2016). Spatial and temporal dynamics of ascidian invasions in the continental United States and Alaska . Marine Biology, 163 (7)
  • Turner, B. C., de Rivera, C. E., Grosholz, E. D. and Ruiz, Gregory M. (2016). Assessing population increase as a possible outcome to management of invasive species. Biological Invasions, 18 (2) , 533-548.
  • Byers, James E., Smith, Rachel S., Pringle, James M., Clark, Graeme F., Gribben, Paul E., Hewitt, Chad L., Inglis, Graeme J., Johnston, Emma L., Ruiz, Gregory M., Stachowicz, John J. and Bishop, Melanie J. (2015). Invasion Expansion: Time since introduction best predicts global ranges of marine invaders. Scientific Reports, 5
  • Kelley, Amanda L., Rivera, Catherine E. de, Grosholz, Edwin D., Ruiz, Gregory M., Yamada, Sylvia Behrens and Gillespie, Graham. (2015). Thermogeographic variation in body size of Carcinus maenas, the European green crab. Marine Biology, 162 (8) , 1625-1635.
  • Keppel, Erica, Tovar-Hernández, Maria Ana and Ruiz, Gregory M. (2015). First record and establishment of Branchiomma coheni (Polychaeta: Sabellidae) in the Atlantic Ocean and review of non-indigenous species of the genus . Zootaxa, 4058 (4) , 499-518.
  • McCann, Linda, Keith, Inti, Carlton, James T., Ruiz, Gregory M., Dawson, Terence P. and Collins, Ken. (2015). First record of the non-native bryozoan Amathia (=Zoobotryon) verticillata (delle Chiaje, 1822) (Ctenostomata) in the Galapagos Islands. BioInvasions Records: International Journal of Field Research on Biological Invasions, 4 (4) , 255-260.
  • Minton, Mark S., Miller, A. Whitman and Ruiz, Gregory M. (2015). Implications of Ship Type on Delivery and Management of Ballast Water. Biological Invasions in Changing Ecosystems: Vectors, Ecological Impacts, Management, and Predictions (343-364) De Gruyter .
  • Muirhead, Jim R., Minton, Mark S., Miller, A. Whitman and Ruiz, Gregory M. (2015). Projected effects of the Panama Canal expansion on shipping traffic and biological invasions. Diversity & Distributions, 21 (1) , 75-87.
  • Ojaveer, Henn, Galil, Bella S., Campbell, Marnie L., Carlton, James T., Canning-Clode, João, Cook, Elizabeth J., Davidson, Alisha D., Hewitt, Chad L., Jelmert, Anders, Marchini, Agnese, McKenzie, Cynthia H., Minchin, Dan, Occhipinti-Ambrogi, Anna, Olenin, Sergej and Ruiz, Gregory M. (2015). Classification of Non-Indigenous Species Based on Their Impacts: Considerations for Application in Marine Management. PLoS biology, 13 (4)