Toward Forcasting Microbial Invasions in the Great Lakes

Untitled Document
Aquatic Invasive Species (AIS): Multiple Species
Project Location: Lake Superior, Duluth-Superior Harbor
Project Start Date: 01/2013
Expected Timeframe/Duration: ongoing
Sponsoring Organization: University of Minnesota-Duluth
Web Links:
Primary Contact: Randall Hicks
University of Minnesota-Duluth

Secondary Contact:
Project Summary:

While the Great Lakes face many threats, the presence of large and small invasive species threatens natural resources, people, and coastal economies.  The introduction and rapid spread of the VHS virus in fish throughout the Great Lakes, including Lake Superior, has lead many to recognize that some microbes can be viewed as harmful invasive species, just like their invasive animal and plant counterparts.

This makes early detection of potentially harmful microbes and extremely important goal.  Ballast water from 29 freshwater and ocean-going commercial ships was sampled in the Duluth-Superior Harbor betwen 2010 and 2012 to identify potentially harmful bacterial taxa.  More than 170,000 partial bacterial 16S rDNA sequences were obtained for each sample, allowing very high detection sensitivity.  DNA sequences were detected from 33 and 14 bacterial genera containing human, and fish and wildlife pathogens, which were often more common than those of tradtional indicator bacteria recommended by the International Maritime Organization for monitoring microbiologicial water safety.  The baterium Piscirickettsia was detected that causes "muskie pox" disease in muskellunge (Esox masquinongy).  DNA from this bacterium was found in 25% of the ships sampled, including ships transporting ballast water from Lake St. Clair where Piscirickettsia was found in dead muskellunge during a 2006 fish kill.  

Next-generation sequencing technology can relatively quickly detect rare microbes of interest that may well be missed by other methods.  Identifying potentially harmful microbes is the first step toward assessing the reisks and impacts of microbial invasions and developing methods to forecast future invasions.