Marine shipping is a major contributor to the spread of marine organisms, allowing these plants, animals, and algae to travel across vast distances that would be impossible for them to do without human assistance. Though microscopic organisms are much more abundant in the marine environment and likely to also be spread through marine shipping, due to their small size, these organisms are much less conspicuous and have not been well-studied in invasion biology. However, there are many examples of the devastating impacts that toxic and parasitic microbes can have when these organisms are introduced into new areas and capable of infecting hosts, including MSX disease in the Chesapeake Bay and crayfish plague in Europe.
Thus, our research on parasite invasions involves understanding the role of humans in spreading marine parasites, assessing the characteristics that make parasites successful invaders, and examining the underlying mechanisms that allow for successful parasite invasions. We examined the protistan communities, including the parasites and toxic taxa, associated with ballast water of commercial ships across multiple US coasts to assess the extend to which marine ships are dispersing these organisms, changing their global distributions and allowing for potential invasions. We are currently assessing the microorganisms, including parasites, associated with the biofilms on the hulls of these ships as well. As these organisms are small and hard to find and identify based on morphology*, we are using genetics, specifically metabarcoding*, to identify microbes in these samples. Finally, we are beginning to examine the characteristics and mechanisms that allow for successful parasite invasions using laboratory experiments to understand how parasites associated with ships can move from the ships to hosts in the surrounding environment.
What Parasites are Hitching a Ride to the Chesapeake Bay in Ballast Water? By Katrina Lohan. February 3, 2014
KM Pagenkopp Lohan, RC Fleischer, KJ Carney, KK Holzer, & GM Ruiz (In press) Molecular characterization of protistan species and communities in ships' ballast water across three U.S. coasts. Diversity and Distributions.
KM Pagenkopp Lohan, RC Fleischer, ME Torchin, & GM Ruiz (2017) Protistan Biogeography: A Snapshot Across a Major Shipping Corridor Spanning Two Oceans. Protist, 168: 183-196.
KM Pagenkopp Lohan, RC Fleischer, KJ Carney, KK Holzer, & GM Ruiz (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.
Dr. Katrina Lohan