In late May, Tom Neligan from Schuyler Falls caught the biggest rainbow trout he had ever landed from the Ausable River, just east of AuSable Forks.

Three-pounders are rare in this river, so when Neligan examined the 19-inch fish, he was shocked to find what appeared to be three lamprey scars on it. He then e-mailed me a photo of the fish and asked, "How far do these fish migrate upstream from the lake (Champlain)?"

With the impenetrable barrier of Ausable Chasm, it didn't seem possible that a rainbow, especially one with sea-lamprey scars could have gotten up to Clintonville and beyond.

I checked with Department of Environmental Conservation fisheries biologist Lance Durfey in Ray Brook, who suggested one possibility I didn't know existed -- silver lampreys.

Yes, there is another lamprey, this one a native species that inhabits fresh water in northern New York state. The silver lamprey should not be confused with the non-native sea lamprey that is wreaking havoc with fish in Lake Champlain. Durfey said silver lampreys can be found in most streams in the Lake Champlain basin, and are particularly common in the Mettawee River in the southeastern Adirondacks.

Silver lampreys grow to a length of 12 inches, their upper bodies silvery or bluish. They are eel-like with sucking mouths. When attached to a host, the silver lamprey will remain there until it is brushed off by the fish. These lampreys seldom kill their food source/host, instead sucking nourishment from the fish's bodily fluids. They leave smaller scars than the more destructive sea lampreys.

Silver lampreys spawn among sand and rocks on stream bottoms in May and June; the adults die when spawning is complete.

So, could silver lampreys be the cause of Neligan's rainbow trout's wounds? After examining the photo, Durfey concluded, "I can't tell for sure, but it looks more like it may be the symptoms of a fish disease, such as furunculosis."

When asked if the fish is edible, he replied, "Yes. Just cook it thoroughly, which is a good idea anyway. Furunculosis is not an uncommon disease in hatcheries."

Alewives and Sea Lampreys

Before the Rotary International Fishing Derby, there was speculation some very big lake trout and salmon would be caught, the result of the alewife explosion in Lake Champlain. Durfey said if that did come about, other reasons would come into play.

"Sea lamprey control is the key to larger salmon and lake trout," Durfey said. "Anglers should not be fooled into thinking that adding alewives to other lakes will make for bigger fish. The impact of that would be a negative one for the fish already there."

With the big (5,000-plus anglers) Father's Day LCI this weekend, we should really get a better take on not only the impact of the alewives, but also if the lamprey control is starting to work.