Carp virus suspected in Lower Colorado River
Cooling waters will likely minimize effects

YUMA, Ariz. — Arizona Game and Fish Department biologists suspect the cause for dead carp that have been observed along the Lower Colorado River and canals near Yuma is from the Koi Herpes Virus (KHV).
KHV is a fish virus that is lethal to koi and carp.

KHV is most active in water temperatures of 72 to 81 degrees. This fish disease impacts gill function and can lead to suffocation and/or secondary infections in carp and koi. KHV can infect grass carp and goldfish but it has not been documented as being lethal to them.

KHV is not a threat to public health, and it is not affecting other wildlife. People should avoid handling the dead fish along the shoreline. Anglers should avoid taking carp and focus on other species during an active outbreak.

“We are seeing evidence of KHV in the Yuma area now that water temperatures are cooling,” said the department’s regional Fisheries Program Manager, Russ Engel. “However, we don’t expect to see the large scale die-offs this fall like we saw this summer at Lake Mohave and Lake Havasu since the water temperatures should drop below the virus’ active range fairly fast.” We also expect to see more cases of KHV next spring as water temperatures again increase into the active range.

KHV is expected to spread throughout the Lower Colorado River and into canals and bodies of water that are fed by the Colorado. There is no known cure or practical treatment of KHV in a natural system like the Colorado River.

For further information, contact Guy Parker, public information officer for the Arizona Game and Fish Department’s Yuma regional office, at (928) 342-0091, or e-mail gparker@azgfd.gov.