With a recent major die-off of carp in Pickerel Lake, a disease known as Koi herpes-virus (KHV) is the suspected culprit.Todd Kaufman, fisheries biologist for South Dakota Department of Game Fish & Parks (GFP) in northeast South Dakota said though KHV has not been confirmed in wild common carp populations in northeast South Dakota, it is suspected in several common carp die offs in r...