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.


  • Davidson, Ian C., Zabin, Chela J., Chang, Andrew L., Brown, Christopher W., Sytsma, Mark D. and Ruiz, Gregory M. (2010). Recreational boats as potential vectors of marine organisms at an invasion hotspot. Aquatic Biology, 11 (2) , 179-191.
  • Doblin, Martina A., Murphy, Kathleen R. and Ruiz, Gregory M. (2010). Thresholds for tracing ships' ballast water: an Australian case study . Marine Ecology Progress Series, 408 , 19-32.
  • Hoos, Phillip M., Miller, A. Whitman, Ruiz, Gregory M., Vrijenhoek, Robert C. and Geller, Jonathan B. (2010). Genetic and historical evidence disagree on likely sources of the Atlantic amethyst gem clam Gemma gemma (Totten, 1834) in California. Diversity & Distributions, 16 (4) , 582-592.
  • Lee, Henry,II, Reusser, Deborah A., Frazier, Melanie and Ruiz, Gregory M. . (2010). Density Matters: Review of Approaches to Setting Organism-Based Ballast Water Discharge Standards. EPA, Office of Research and Development .
  • Rup, Michael P., Bailey, Sarah A., Wiley, Chris J., Minton, Mark S., Miller, A. Whitman, Ruiz, Gregory M. and MacIsaac, Hugh J. (2010). Domestic ballast operations on the Great Lakes: potential importance of Lakers as a vector for introduction and spread of nonindigenous species. Canadian Journal of Fisheries and Aquatic Sciences, 67 (2) , 256-268.
  • Davidson, Ian C., Brown, Christopher W., Sytsma, Mark D. and Ruiz, Gregory M. (2009). The role of containerships as transfer mechanisms of marine biofouling species. Biofouling, 25 (7) , 645-655.
  • Fofonoff, Paul W., Ruiz, Gregory M., Hines, Anson H., Steves, Brian D. and Carlton, James T. (2009). Four centuries of biological invasions in tidal waters of the Chesapeake Bay region. Biological invasions in marine ecosystems (479) Springer-Verlag .
  • Grosholz, Edwin D. and Ruiz, Gregory M. (2009). Multlitrophic effects of invasions in marine and estuarine systems. Biological Invasions in Marine Ecosystems (305) Springer-Verlag .
  • Miller, A. Whitman and Ruiz, Gregory M. (2009). Differentiating successful and failed invaders: Species pools and the importance of defining vector, source and recipient regions. Biological Invasions in Marine Ecosystems (153) Springer-Verlag .
  • Murphy, Kathleen R., Boehme, Jennifer R., Noble, Monaca, Smith, George E. and Ruiz, Gregory M. (2009). Deducing ballast water sources in ships arriving in New Zealand from southeastern Australia. Marine Ecology Progress Series, 390 , 39-53.
  • Riedlecker, Eva I., Ashton, Gail V. and Ruiz, Gregory M. (2009). Geometric morphometric analysis discriminates native and non-native species of Caprellidae in western North America. Journal of the Marine Biological Association of the United Kingdom, 89 (3) , 535-542.
  • Ruiz, Gregory M. and Hewitt, Chad. (2009). Latitudinal Patterns of Biological Invasions in Marine Ecosystems: A Polar Perspective . Smithsonian at the Poles: Contributions to International Polar Year Science (347-358)
  • Ruiz, Gregory M., Freestone, Amy L., Fofonoff, Paul W. and Simkanin, Christina. (2009). Habitat distribution and heterogeneity in marine invasion dynamics: The importance of hard substrate and artificial structure. Marine Hard Bottom Communities (321-332) Springer Berlin Heidelberg .
  • Ruiz, Gregory M., Torchin, Mark E. and Grant, Katharine. (2009). Using the Panama Canal to Test Predictions about Tropical Marine Invasions. Proceedings of the Smithsonian Marine Science Symposium (291-299) Smithsonian Institution Scholarly Press .
  • Santagata, Scott, Bacela, Karolina, Reid, David F., Mclean, Kevin A., Cohen, Jill S., Cordell, Jeffery R., Brown, Christopher W., Johengen, Thomas H. and Ruiz, Gregory M. (2009). Concentrated sodium chloride brine solutions as an additional treatment for preventing the introduction of nonindigenous species in the ballast tanks of ships declaring no ballast on board . Environmental Toxicology and Chemistry, 28 (2) , 346-353.