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The Sea Lamprey Control Risk Assessment team studies the effects of lampricide treatment on non-target species in the Conneaut Creek, PA. A priority this winter is to evaluate spawner abundance in Lake Erie to gauge effect of lampricide treatment of the creek. Photo by Joanna Gilkeson/USFWS.

The Sea Lamprey Control Risk Assessment team studies the effects of lampricide treatment on non-target species in the Conneaut Creek, PA. A priority this winter is to evaluate spawner abundance in Lake Erie to gauge effect of lampricide treatment of the creek. Photo by Joanna Gilkeson/USFWS.

Out of Sight is not Out of Mind

While a blanket of white frosts the ground, the disc-like mouth sucking threat- the sea lamprey - is cloaked safely beneath, and the U.S. Fish and Wildlife Service’s Sea Lamprey Control team is bustling, planning and prepping for the next field season.

During the “off-season”, priorities for the team include planning an effective sea lamprey treatment schedule to reach sea lamprey suppression targets in each Great Lake. Suppression targets are sea lamprey population goals based on a calculation of estimated average abundance numbers of sea lamprey over a five-year period. Each lake has its own goal. In 2014, the adult sea lamprey abundance target was 75,891 for Lake Huron, which the team achieved.

Setting the treatment schedule for each field season requires a lot of coordination with other federal, state and tribal partners to find the optimum window that ensures removal of sea lampreys while minimizing the effect to other species.

Determining the best treatment for each individual tributary entering the Great Lakes watershed is a demanding task. Service fish biologists consider many factors- stream water volume, regulated flow patterns, pH cycles, sensitive species and detailed notes from previous treatments.

Another “off-season” priority for the team is calculating abundance of adult sea lampreys in each Great Lake. Currently, for Lake Erie they will gauge the effect of the lampricide treatment of Conneaut Creek in Pennsylvania. Conneaut Creek has long been a sea lamprey producing stream. In 2013, a portion of the stream was left untreated to protect the hornyhead chub. The hornyhead chub is common among the Great Lakes, but has only small populations in two Pennsylvania streams, and Conneaut Creek is one of those. To protect this fish in Pennsylvania, the Service partnered with Pennsylvania Fish and Boat Commission (PFBC) to attempt removal of larvae using backpack electrofishers in 2013.

“While this effort pulled thousands of large sea lamprey ammocetes from the system, it was very costly and not effective at reducing the larval population,” Shawn Nowicki, Larval Unit Supervisor for the Marquette Biological Station stated.

To solve the horneyhead chub issue, the Service’s Sea Lamprey Control Risk Management team conducted a biological assessment that demonstrated hornyhead chubs are not sensitive to lampricide in the concentration it is applied to the stream. Sea Lamprey Control presented the findings to the State of Pennsylvania and requested to start treating the creek.

The Service collaborated with the PFBC to successfully treat the creek using lampricide in the spring of 2015 with no effect to the hornyhead chubs.

Additional priorities during the coming year include coordinating and monitoring of the Manistique and Grand River barriers in Lake Michigan. Both projects are funded through the U.S. Army Corps of Engineers as part of the Great Lakes Fishery and Ecosystem Restoration program. A new sea lamprey barrier being constructed on the Manistique River, located in the upper peninsula of Michigan, is replacing the Manistique Papers, Inc. dam that has deteriorated over time and resulted in increased numbers of sea lamprey into Lake Michigan. For the Grand River, a feasibility study to investigate construction of a new adjustable crest barrier and rehabilitation of the river channel to improve flood protection, river habitat and recreational use while preventing sea lampreys from migrating upstream is currently ongoing. This barrier would replace the Sixth Street Dam in Grand Rapids, Michigan. Both barriers are crucial to sea lamprey control.

By Mara Koenig
Regional Office - External Affairs

                                                                                             

Last updated: January 6, 2016