Sea Lamprey: Invasive or Native?

In the summer of 2009 my dad and I went on a fishing trip in Lake Champlain. We hired Rich Greeno who was a family friend to take us down rigger fishing for many of the deepwater fish species in Lake Champlain including Landlocked Salmon and Lake Trout. In the  hours that we spent fishing on the lake we pulled up 22 Lake Trout varying in size from 12-25 inches in length. It was on this marvelous day of fishing however that I realized the extent of the Sea Lamprey problem in Lake Champlain.  Out of the 22 fish we caught 4 of them had living Lamprey attached to them, and 12 of the remaining 18 had scars that were caused by Sea Lamprey at one point in their life. Only 6 of the 22 fish caught had no evidence of Sea Lampreys. 

Populations of sea lampreys were first identified in Lake Champlain in 1929. It was thought that the Sea Lamprey were an invasive species that came into Lake Champlain through the Hudson/Champlain Canal in the 1800’s. However recent genetic studies have indicated that the sea lamprey may actually be a native species in Lake Champlain.

            University of Vermont Associate Professor Ellen Marsden recently presented information that could help prove that Sea Lamprey are in fact a native species to the Lake Champlain Ecosystem.

(http://www.mychamplain.net/forum/lake-champlain-sea-lamprey-control-alternatives-workgroup-meeting)

Dr. Marsden discusses genetic research that seems to support the idea that Sea Lamprey are a native species to Lake Champlain. For this to be true Sea Lamprey, Lake Trout, and Salmon populations would have coexisted in lake Champlain for thousands of years. This should have led to evolutionary traits in Salmon and Lake Trout to combat the Lamprey, leaving the question of why the sudden increase in reports? This is due to the fact that the Lake Champlain strains of salmon and lake trout are lost forever.

             The negative impact on Lake Champlain's fishery and ecosystem as a result of Sea Lamprey may be able to be explained by two factors. The first factor is the major change in human use of the Lake Champlain watershed. This may have resulted in an increased habitat for larval lamprey. The other factor is that the strain of Atlantic salmon being stocked in Lake Champlain currently did not evolve in the presence of lamprey and therefore may be more susceptible to sea lamprey damage. This does not hold true for the current Lake Trout strain that is being stocked. Studies have shown that the new strain now being stocked is exhibiting a greater tolerance to the Sea Lamprey.

            As the debate rages on as to whether this nuisance species of lamprey is invasive one thing has become clear. Invasive or not Sea Lamprey populations need to be controlled in order to keep healthy Lake Trout and Salmon populations in Lake Champlain.

(http://www.dec.ny.gov/animals/6998.html)

"Sea Lamprey Experts." - NYS Dept. of Environmental Conservation. Web. 02 Apr. 2012. <http://www.dec.ny.gov/animals/7236.html>.

"Sea Lamprey." - NYS Dept. of Environmental Conservation. Web. 02 Apr. 2012. <http://www.dec.ny.gov/animals/6998.html>.