A deadly fish disease, viral hemorrhagic septicemia virus (VHS), that has plagued North America's Great Lakes since 2005, could increasingly impact the balance of wildlife and affect fishing industries in the region, according to joint research from Cornell University and the United States Geological Survey (USGS).

During the study by the Cornell’s College of Veterinary Medicine and the USGS Western Fisheries Research Center in Seattle, scientists examined 874 fish from seven sites. Four of the seven locations tested positive for the virus.

According to a statement from the USGS, “VHS is the most important viral pathogen of finfish worldwide and is listed as a reportable pathogen by many nations and international organizations.”

The virus has been found across the Great Lakes region, which houses a chain of five bodies of water containing the largest surface of freshwater in the world. So far, it has been recorded in four out of five Great Lakes including Lake Michigan, Lake Huron, Lake Ontario and Lake Erie, as well as in Lake Saint Clair and the Saint Lawrence River.

The virus has infected many species in the region, including muskellunge, freshwater drum, goby, burbot, yellow perch, gizzard shad and smallmouth bass. During one outbreak in Lake Ontario, the virus killed 40,000 freshwater drum in four days.

Recently, scientists also reported instances of VHS in inland lakes in Wisconsin and Michigan—a sign the virus is spreading.

According to information provided by the USGS, “If the virus spreads outside the Great Lakes Basin or into the private aquaculture sector, the biological and economic impacts are expected to be very large.”

USGS researcher Dr. James Winton expanded on its potential impact.

“It not only affects the health and well-being of populations of several important native fish species, but it can also impact trade, and, should it spread into the U.S. aquaculture industry, could do substantial damage as happened in Europe and parts of Japan.”