A crew from the Illinois River Biological Station was conducting an electrofishing survey near a wing dam in Pool 22, close to Hannibal, Missouri. The work was part of a graduate research project focused on blue suckers.
One technician had just placed a blue sucker in the livewell when a graduate student, who also works for the Missouri Department of Conservation, suddenly reached into the water with a dip net.
“EEL!” he shouted as he turned around holding the unexpected catch.
The American eel measured just under 950 millimeters, or slightly more than 37 inches. It was one of the largest American eels members of the research crew had ever encountered. However, catching it was only part of the challenge. American eels are extremely muscular and covered with a protective layer of mucus, making them difficult to hold. They can also twist forward or backward to escape from a dip net.
The Illinois River Biological Station described the fish as a “solid 3-foot-long tube of muscle and slime.” One member of the station’s crew could recall handling only three American eels since arriving in Illinois in 2013.
While the fish was a rare sight in that stretch of the Mississippi River, its presence also highlighted one of the most remarkable migrations in North America.
American eels are the continent’s only freshwater eel species. According to the U.S. Fish and Wildlife Service, they begin life in the Sargasso Sea, an area of the North Atlantic Ocean. Their larvae drift toward the coast on ocean currents before developing into young eels and entering rivers.
Some remain in coastal or brackish water, but others travel thousands of miles inland through river systems, including the Mississippi. They can spend 10 to 25 years growing in freshwater before mature eels make the long journey back to the Sargasso Sea to reproduce.
Researchers believe the eel found near Hannibal may have traveled more than 2,000 miles before reaching Pool 22.
After taking several photographs, the crew safely released the eel into the Mississippi River. The muscular traveler quickly disappeared back into the water, leaving researchers with one of the most memorable catches of their careers.
