Viral communities in ballast water in the Great Lakes
This article is Part Two of a two-part series.
Editor’s Note: This article series is the result of a student engagement program through Michigan State University Extension and Michigan Sea Grant helping to prepare the next generation of natural resource professionals with practical experience in Extension outreach and engagement. This article is the second in a two-part series.
Non-native invasive species such as plants, fishes, algae and mollusks have been impacting the Great Lakes since the 1800s. Currently, there are over 180 non-native species established in the Great Lakes. (Read first article.) In order to learn more about the diversity of viral communities, known as viromes, in ballast water, researchers turned to the tanks of vessels in Great Lakes ports.
Joan Rose, Homer Nowlin Endowed Chair of Water Research and colleagues at Michigan State University used metagenomic techniques (e.g., sequencing of community DNA and RNA) to investigate viral communities in ballast water in the Great Lakes region and recently published an article in the scientific journal “Environmental Science & Technology” (Kim et al. 2015). The authors analyzed samples from ballast waters from different sources (e.g., ships) around the Great Lakes and paired them with harbor water samples from the Port of Duluth-Superior. Through their analysis, which included bioinformatics analysis of over 550 million sequences, the authors found the majority of viral sequences did not match any taxa associated with reference sequences (essentially could not be identified through the library of reference sequences). Bacterial viruses (known as bacteriophages) were most abundant in the samples from ballast and harbor waters however potentially emerging or reemerging viral pathogens of fish and shrimp were also identified.
Specific viral pathogens affecting fish found in the ballast water samples included infectious spleen and kidney necrosis virus, koi herpesvirus, and striped jack nervous necrosis virus. With first reports of the disease in Europe, koi herpesvirus, or KHV, was introduced into the Great Lakes region and has been the cause of multiple fish kills of common and koi carp species since 2004. Fish with koi herpesvirus disease (KHVD) have symptoms that include pale discoloration or reddening of the skin, sunken eyes, hemorrhaging on the skin, fin erosion, and lethargy; although some fish may suffer loss of equilibrium and show signs of hyperactivity. As many fish diseases have similar symptoms, cause of disease is verified by laboratory testing. Striped jack nervous necrosis virus is different from KHV in that external symptoms from the virus are rare, but infected fish exhibit erratic swimming patterns, such as whirling or resting belly-up, as their brain, central nervous system and retina are affected. Striped jack nervous necrosis virus has been found in many parts of the world – including countries in Asia, Europe, the Mediterranean, and North America – affecting more than 50 susceptible species of fish, including striped jack, European sea bass, groupers, and flatfishes. Viral pathogens affecting shrimp identified in the study were infectious myonecrosis virus, macrobrachium rosenbergii nodavirus, taura syndrome virus, and white spot syndrome virus. White spot syndrome first appeared in China in 1992 and caused severe impacts in farmed shrimp. White spot syndrome virus causes white spots in the exoskeleton and can also cause reddish or pinkish discoloration, these symptoms, along with lethargy and a decrease in food consumption causes a very high mortality rate in farmed shrimp. It appeared in the Americas in 2001 through international trade of live shrimp and other crustaceans. These viral pathogens can cause a wide range of affects on fish and shrimp. By learning more about potential viral pathogens in ballast water, the study contributes to improving our knowledge of water treatment methods needed to inactivate the viral pathogens.
Freshwater viromes in the samples in this study were closely related to viromes found in lakes Pavin and Bourget in France, and in an Antarctic lake, indicating that the ballast waters being discharged into the Great Lakes include taxonomic communities from around the world. Indeed, ships in our Great Lakes ports come from all around the world, and discharge approximately 6.6 million gallons of ballast water into the Great Lakes annually. In order to understand the Great Lakes as part of a global systems, we must be able to see the whole picture and understand the relationships that local issues have to distant places.
Using the concept known as telecoupling, developed by Jianguo "Jack" Liu, University Distinguished Professor of Fisheries and Wildlife at Michigan State University and Director of the Center for Systems Integration and Sustainability at Michigan State University, we can better understand our global interactions, including the spread of viral diseases. Telecoupling examines the relationship between natural and socioeconomic systems both locally and globally, explicitly in this case, the connection between the economic and the environmental forces behind global shipping, commerce and the introduction and spread of these viruses in the Great Lakes. (Liu et al. 2013).
- Part One in this series: Shipping, commerce and the introduction of non-native species in the Great Lakes
- About Our Great Lakes: Economy. Retrieved August 10, 2015, from http://www.glerl.noaa.gov/pr/ourlakes/economy.html
- Economic Impact of Great Lakes Shipping. Retrieved August 10, 2015, from http://www.marinedelivers.com/economic-impact-great-lakes-shipping
- Kim, Y., Aw, T.G., Teal,T.K, and Rose, J.B. 2015. Metagenomic investigation of viral communities in ballast water. Environmental Science & Technology. 49 (14), pp 8396–8407.
- Liu, J., Hull,V., Batistella,M., DeFries,R., Dietz, T., Fu, F., Hertel, T.W., Izaurralde, R.C., Lambin, E.F., Li, S., Martinelli, L.A., McConnell, W.J., Moran, E.F., Naylor, R., Ouyang, Z., Polenske, K.R., Reenberg, A., de Miranda Rocha, G., Simmons, C.S., Verburg, P.H., Vitousek, P.M., Zhang, F., and Zhu, C. 2013. Framing sustainability in a telecoupled world. Ecology and Society 18(2): 26. http://dx.doi.org/10.5751/ ES-05873-180226
- Mills, E.L., Leach, J.H., Carlton, J.T., Secor, C.L. 1993. Exotic species in the Great Lakes: A history of biotic crises and anthropogenic introductions. Journal of Great Lakes Research. 19(1):1-54.
- Rosaen, A. L., E. A. Grover, C. W. Spencer, with P. L. Anderson. 2012. The costs of aquatic invasive species to Great Lakes States. Report by the Anderson Economic Group, LLC, East Lansing, MI.