Fish collected from 22 sites throughout Ohio recently tested negative for Viral Hemorrhagic Septicemia (VHS). The monitoring study, conducted in Fall 2007 and Spring 2008, was a collaborative effort of the Ohio Sea Grant College Program, the U.S. Fish and Wildlife Service Reynoldsburg Office, the Ohio Department of Agriculture (ODA), and the U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA-APHIS) Veterinary Services.
Collection protocols followed USDA sampling procedures, which required the capture of 170 susceptible fish per site. Testing was completed by ODA’s Division of Animal Industry. Negative results were found for all sampled fish, including those caught in Clear Fork Reservoir, where the Ohio Department of Natural Resources’ Division of Wildlife recently collected muskellunge (muskie) ovarian fluid that tested positive. The Ohio Sea Grant sample from Clear Fork did not include muskellunge.
Fish suffering from VHS can display hemorrhaging of internal organs, skin, and muscle. If bleeding is externally visible, it will be particularly evident in the eyes, gills, and at the bases of the fins. Other symptoms can include darkened coloration, a bloated abdomen, bulging eyes, and lethargy or abnormal swimming and darting. It is possible for fish to carry the virus but show no clinical signs.
VHS is not related to the Ebola virus, and it cannot harm humans. The VHS virus can survive only in cool environments, typically being found in the spring and, more rarely, in the fall, and therefore cannot survive at the body temperature of warm-blooded animals. The public should not be afraid to consume any apparently healthy fish caught in Ohio waters.
"I’m skeptical regarding the substantial long-term impact of VHS on large, wild fish populations," said Eugene Braig, assistant director of Ohio Sea Grant. "You can expect a couple seasons of high mortality with an initial introduction, but a virus seldom causes 100% mortality, and exposed organisms that survive often develop some type of immunity. For example, it should be noted that there have been no substantial confirmed VHS-related kills on Ohio’s Lake Erie waters after spring 2006 in spite of the virus’ continued presence."
An ongoing federal order imposed by the USDA-APHIS restricts international and interstate transport of susceptible fish species. ODA also restricts the movement of susceptible fish across a line defined by U.S. Route 6 in the west and Interstate 90 in the east that separates Lake Erie from Ohio’s inland waters. Fish may be caught and released within a single body of water that spans state or international boundaries, such as Lake Erie.
More information about VHS, as well as the susceptible species list, can be found at www.aphis.usda.gov/animal_health/animal_dis_spec/aquaculture/ .
For more information contact:
Eugene Braig, Assistant Director, Ohio Sea Grant, firstname.lastname@example.org, 614-292-8949