EMU team trying to stem Great Lakes invasion
YPSILANTI - It’s a problem that biologists are racing to solve. Sea lampreys have invaded the Great Lakes and their aggressive feeding behavior has drastically affected the surrounding area's fisheries.
Among those using their expertise are an Eastern Michigan University professor and an EMU student. Uli Reinhardt, assistant professor of biology, and Robert Adams, a biology major from Novi, are conducting research in EMU's Aquatic Ecology Research Facility to prevent sea lampreys from swimming upstream to spawn.
"The behavior of the sea lampreys has not been studied in great detail, which is surprising given the damage this invasive species is causing in the Great Lakes region," said Reinhardt.
Sea lampreys were accidentally introduced into the Great Lakes in the early 20th century through shipping canals. Because they didn't evolve naturally in this environment, they had a strong advantage over their fish prey. According to the Great Lakes Fishery Commission, sea lampreys are so destructive that they can kill 40 or more pounds of fish in their lifetime.
Before sea lampreys existed in the Great Lakes, Canada and the United States harvested about 15 million pounds of lake trout annually in lakes Huron and Superior. By the early 1960s, the catch was only about 300,000 pounds in these two lakes.
The main goal of the research is to measure the sea lamprey's suction pressure on surfaces with different textures, shapes, depths and widths. If the fish are attracted to one surface more than another, Reinhardt and Adams will make an attachable surface to the low-head barriers in the lakes preventing the sea lampreys from swimming upstream to spawn.
Strategically located downstream from spawning habitats, the sea lamprey barriers have a
2-to-4-foot drop to stop them from swimming beyond the barriers. A lip is often used on the low-
head dams, keeping the sea lampreys from using their suction cup mouth to climb over the barriers.
"We are looking for some kind of validation to see if they can detect these different surfaces," said Adams. "This is a real novel way of looking at this type of research because it has never been done before and we really don't know what their capabilities are yet."
Although the barriers were constructed to allow other species of fish through, sea lampreys sometimes manage to slither through them as well.
"We don't know yet how the sea lampreys manage to pass through some of the low-head dams that have been built to block their upstream spawning migration," said Reinhardt. "It is important to find out the strategies these fish use to pass obstacles, so that we can design better low-head dams and traps."
Resembling eels, the sea lamprey is able to live in both saltwater and freshwater. The 6-inch-long sea lampreys act like parasites and attach themselves to their prey and feed off their victim's body fluids. Using their sharp teeth and long grasping tongue, they latch onto large fish such as salmon, trout and catfish.
Although sea lampreys have been around for several decades, there is no advantage to them existing in the Great Lakes.
"Eventually we hope that sea lampreys will be totally wiped out (in the Great Lakes region), but that will be really hard to do," said Adams. "Out west, sea lampreys are actually becoming endangered and aren't harmful to the fish habitat because they naturally existed in that environment. Those fish (out west) have a defense against them and know how to react. Barriers are in place out there to guide the sea lampreys to the right places to spawn whereas, in the Great Lakes, we want to stop them."
Reinhardt and Adams began the pressure testing with about 135 fish, a number that is slowly dwindling. Kept in three large tanks, the fish are not only measured through data analysis, but are filmed as well. Reinhardt plans to continue his collaboration with the Great Lakes Fishery Commission and research with his students for improved management techniques for the sea lampreys.
The Great Lakes Fishery Commission, which funded the grant for the research, coordinates the fisheries research that helps control the sea lamprey population. The Commission also facilitates cooperative fishery management among the state, provincial, tribal and federal management agencies. Along with the fishery commission, the U.S. Geological Survey and universities throughout the Great Lakes basin also conduct critical sea lamprey research.
Overall, the sea lamprey control program has been successful, resulting in a 90-percent reduction of them in most areas. Ongoing efforts have helped to create a healthy environment for fish survival and spawning. As a result, the Great Lakes region fishery is finally starting to recover."The cost of ongoing sea lamprey management is considerable and efforts spent on research of their behavior may pay off handsomely in future savings," said Reinhardt.
Eastern Michigan University is a public, comprehensive university that offers programs in the arts, sciences and professions. EMU prepares students with the intellectual skills and practical experiences to succeed in their careers and lives, and to be better citizens.
Eastern Michigan University is a public, comprehensive university that offers programs in the arts, sciences and professions. EMU prepares students with the intellectual skills and practical experiences to succeed in their career and lives, and to be better citizens.
Editor's Note: Looking for an expert source for a story? Check out EMU's Eastern Experts online at www.emich.edu/univcomm/easternexperts.