Speaker: Dr. Tom Lauer
Sea Lampreys are an invasive parasitic species in the Great Lakes. After their introduction in the early 20th century, they dramatically altered the ecosystem, killing off most of the large bodied fish. In the 1950s, the Great Lakes Fishery Commission was created to address the problem and has been successful in many respects. The current cost of control is $30 million/year, while the benefit to the fishery is $7 billion/year. In this presentation, he will discuss the biology of the sea lamprey, the history along with the biological impact, control mechanisms, and its future in the Great Lakes. This is another example of the negative impact that an invasive species has in our environments.
About the Speaker: Thomas Lauer, BS and MS Ball State University, PhD Purdue University. Director and Distinguished Professor Emeritus, Aquatic Biology and Fisheries Center, Ball State University. Dr. Lauer is an Advisor for the international Great Lakes Fishery Commission and a Scientech member.
Program: Live and Zoom: Sea Lampreys: The Scourge of the Great Lakes
Speaker: Thomas E. Lauer PhD, Sciente4ch Club Member
Introduced By: Karen Bumb Lauer
Attendance: NESC: 96; Zoom: 29
Guest(s): Alli Badgero, Mark Williams
Scribe: Tom Lauer
Editor: Ed Nitka
View a Zoom recording of this talk at:
https://www.scientechclubvideos.org/zoom/04142025.mp4
Today's speaker was Tom Lauer, PhD, Director and Distinguished Professor Emeritus, Aquatic Biology and Fisheries Center, BSU; Advisor, Great Lakes Fishery Commission and more
The Great Lakes (Superior, Michigan, Huron, Erie, and Ontario) hold 1/5 of the freshwater in the world. They drain to the Atlantic Ocean via the St. Lawrence Seaway. The lakes in their current form are the result of the last glacier that covered the Midwest approximately 10,000 years ago. Lake Michigan is wholly within the U.S., while the other four lakes are shared by two countries, the U.S. and Canada.
Prior to European immigrants, the lakes were home to Native Americans who existed on a subsistence lifestyle, which included fishing. Given the vast resource and the limitations of handmade boats, the fishing appeared unlimited. However, with the European immigrants in the 1800s, fishing in Lake Ontario soon was extensive. Coupled with pollution and some development (e.g., grist mills), declines in commercial fish harvest occurred by the 1850s. When this happened, commercial fishers simply moved to the upper lakes where fish were plentiful and continued their harvesting. At the turn of the 20th century, up to 100 million fish were harvested out of Lake Erie alone. In 1924, 32 million pounds of Cisco (a salmon family fish) was harvested, but only 5 million pounds were harvested the next year. Something seemed amiss with such a rapid decline.
The Sea Lamprey was first found in Lake Ontario in 1836, in Lake Erie in 1921, Lake Michigan in 1936, Lake Huron in 1937, and Lake Superior in 1938. By the 1950s, they had not only spread throughout the Great Lakes but had developed a massive infestation and were seen as the problem to the declining fisheries. To solve the Sea Lamprey problem, scientists needed to know what they were dealing with and needed to understand their life cycle. Vernon Applegate was asked to do just that while working on his PhD degree in Michigan. He saw that fish spawned in the rivers and larval fish stayed there for 3-5 years filtering water for food. Then they swam out to the lakes where they became parasitic for 12-18 months, then as mature adults, they migrated back to the streams to spawn, dying thereafter.
Control of the Sea Lamprey in the Great Lakes was thought to be best done while the fish were in the streams at the larval stage in their life. Electric barriers and traps didn’t seem to work very well. Thereafter, a search for a pesticide that would kill Sea Lamprey but not harm any organisms was sought. It took five years, and 5209 chemicals evaluated to find that pesticide, 3-trifluoromethyl-4-nitrophenol, or TFM for short. Success was measured by how many adult Sea Lampreys came to spawn in the streams and by how many marks or scars were found on large-bodied fish.
The cost of control is approximately $30 million/year, which supports $7 billion in economic benefit.
Ongoing, continual control is mandatory for this fish. During the first two years of Covid, few streams were treated, allowing larval Sea Lampreys to again move to the lake and become predators. Hence, ongoing control indefinitely is mandatory for control. This TFM program brough an invasive species under control, held it, and restored ecosystem integrity. Because of the success and the scale, the Sea Lamprey program has been called the greatest example of invasive species restoration in the world.
Further information can be found in the recently released documentary on streaming TV, “The Fish Thief, A Great Lakes Mystery”.
Tom Lauer
