Officials of the Illinois Department of Natural Resources went fishing last August to collect samples. They caught largemouth bass at four lakes and two fish hatcheries, but shared no smiles.
The bass in all six locations, says a University of Illinois scientist, were infected with a virus they were seeking but didn’t expect to find.
The virus -- now confirmed in 17 states -- is called the largemouth bass virus (LMBV) because only this species is dying from it. That no fish kills have been reported in Illinois is good news, but it also deepens the mystery as to the virus’s origin and variability.
"It was found in all four lakes and both state hatcheries -- the only places we looked," said Tony Goldberg, a professor of veterinary pathobiology in the UI College of Veterinary Medicine who is studying LMBV. "This surprised everybody. It was shocking, because we hadn’t experienced any of the clinical signs typically linked with the virus."
Goldberg and David Philipp, a scientist with the Illinois State Natural History Survey Center for Aquatic Ecology at the UI, have launched a three-year national study to do on-site examinations in affected areas and laboratory experiments in which they will raise largemouth bass and expose them to environmental stressors and to the virus. They want to know what triggers susceptibility to the virus.
Goldberg details the virus, which poses no health risk to people who eat infected fish, in a chapter of "Black Bass 2000: the Ecology, Conservation and Management of Black Bass in North America," to be published later this year by the American Fisheries Society.
When active, usually in summer months, the virus attacks both sexes and all ages of largemouth bass (Micropterus salmoides); they lose equilibrium, float to the surface and die.
"One of the most interesting things about this virus is its clinical variability," Goldberg said. "Some fish populations experience large-scale fish kills, but others appear perfectly normal. Nobody knows why some die and some do not. We want to know if the clinical variability is tied to environmental changes. There has been a concern for years that such things as habitat alteration, dissolved toxins or even global warming may stress wildlife populations. We think there is something like this going on with largemouth bass."
Preliminary data suggest the virus in Illinois is not as deadly as that found in South Carolina lakes, he said. The virus was found in Cedar, Jacksonville, Crab Orchard and Lou Yaeger lakes and in the Little Grassy and Jake Wolfe hatcheries in Illinois. Two of the lakes were stocked from the hatcheries. No bass deaths had been noted in the lakes before the survey that was coordinated by Mike Conlin, chief of fisheries at IL-DNR. Tissue samples from the bass were tested at the La Crosse Regional Fish Health Center in Wisconsin.
LMBV is an iridovirus, a family of virus that only affects fish, amphibians and reptiles. Genetically, it is similar to a pathogen of aquarium fish from Southeast Asia, suggesting the virus may have been imported, Goldberg said. While found in other fish, LMBV so far has only caused mortality in largemouth bass. In experiments, it has adversely affected hybrid striped bass, an aquaculture cross of female white bass (Morone chrysops) and male striped bass (Morone saxatilis) that is often raised in hatcheries.
The virus was discovered in 1995 in the Santee Cooper Reservoir of South Carolina, where it killed 1,000 largemouth bass. It has since been found elsewhere, including last year in Indiana and Michigan. Not all states have tested for the presence of the virus. A mysterious 1991 Florida fish kill may have been from LMBV, scientists now theorize.
The UI research is funded by the Conservation Medicine Center of Chicago, a consortium of the Brookfield Zoo, Loyola College of Medicine and the UI College of Veterinary Medicine, and the Illinois Council on Food and Agricultural Research.
The national survey is being done in collaboration with the U.S. Fish and Wildlife Service’s Warm Springs Regional Fisheries Center in Georgia.
Jim Barlow | Daily University Science News
Climate change, population growth may lead to open ocean aquaculture
05.10.2017 | Oregon State University
New machine evaluates soybean at harvest for quality
04.10.2017 | University of Illinois College of Agricultural, Consumer and Environmental Sciences
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research