Crews Take On Sea Lamprey in the 2015 Field Season
BY JOANNA GILKESON, EXTERNAL AFFAIRS-REGIONAL OFFICE
treatment on the St. Mary's River in Michigan's Upper Peninsula. Credit: Joanna
The 2015 Sea Lamprey Control treatment field season officially began on April 6.
The U.S. Fish and Wildlife Service’s Sea Lamprey Control Program is the U.S. entity responsible for sea lamprey control working in close partnership with their Canadian counterpart, the Department of Fisheries and Oceans, Canada. In case you’re wondering what a sea lamprey is, it is a voracious invasive species with a large appetite for important fish species, such as lake trout and pacific salmon, which are vital to the ecosystem and economy of the Great Lakes.
On April 6, the Service’s program will begin a two-week period of strenuous safety training to prepare for the upcoming field season. Meanwhile, the Department of Fisheries and Oceans staff will begin treating streams in western New York to control sea lampreys in Lake Erie.
Sea lampreys, native to the Atlantic Ocean, invaded the Great Lakes through manmade shipping canals. The first recorded observation of a sea lamprey in the Great Lakes was in 1835 in Lake Ontario. Historically, Niagara Falls served as a natural barrier to entry and sea lamprey were confined to Lake Ontario. Improvements to the Welland Canal, which bypasses Niagara Falls and provides a shipping connection between Lake Ontario and Lake Erie, allowed sea lampreys quick access to the rest of the Great Lakes in the early 1900s.
Sea lampreys parasitize many species of fish, such as lake trout, lake sturgeon and salmon, often killing the host fish. Sea lampreys became so abundant that they ultimately decimated the Great Lakes fisheries and local economies in the area by the 1950s. See graphical representation of lake trout abundance after sea lamprey invasion in the 1930s.
During 2014 we worked with our Canadian counterparts to apply lampricides at 85 Great Lakes locations to reduce sea lamprey numbers. These treatments require staff to work around-the-clock in 5 to 6 day shifts.
2014 in a nutshell:
- Treated 85 streams and lentic areas in the Great Lakes
- Detected and determined the extent of sea lamprey larval infestations in 549 streams.
- Operated and maintained 34 barriers to block spawning runs of adult sea lampreys.
- Fished traps at 55 sites to estimate abundance of adult sea lampreys.
- Adult sea lamprey abundance levels were within or below targets in 4 of 5 Great Lakes.
Lake Erie is the exception. Lakes Superior, Michigan, Huron and Ontario are within or below sea lamprey abundance target levels. In response, we have been paying careful attention to Lake Erie since 2010 and will continue to do so.
The question we are currently trying to answer is “where are the sea lamprey in Lake Erie coming from?” Recent assessments show that sea lamprey adult abundance in Lake Erie tributaries are still elevated, but have decreased substantially since 2009. In efforts to bring down sea lamprey levels in Lake Erie, we are monitoring the St. Clair River population, treating new areas identified as contributing to the Erie population and searching for new sea lamprey producing streams in the basin.
To restore the Great Lakes ecosystem and revive the fisheries, the U.S, and Canada have been treating Great Lakes tributaries with lampricides since the late 1950s, which we rely on to kill the sea lamprey before it reaches its parasitic life phase. In addition to lampricides, other control mechanisms are incorporated into our toolbox including barriers, larval and adult assessments, and ongoing research to help us combat this invasive predator. Thanks to these tools and a strong international partnership, we have been successful in reducing sea lampreys by about 90% from historic highs.
The Sea Lamprey Control Program carried out by our staff and Canadian partners is administered by the Great Lakes Fishery Commission, operating under the Convention on Great Lakes Fisheries, a treaty between the US and Canada, since 1955. Stay tuned for updates to learn more about our 2015 field season and accomplishments in sea lamprey control.