Long, slick and wiggly — American eel reaches the Ohio
Jesse St. Esprit, of Center, was recently on the Ohio River in Beaver County, night fishing for flathead catfish. Instead, his cut bait caught the attention of a 4foot American eel, which he boated, photographed and released.
Despite its snakelike appearance, it’s a fish. Opposite of salmon migration, the eel is the only North American fish that spawns in saltwater and migrates to freshwater streams, where it lives most of its life.
Elements of the eel’s curious life cycle were not known until the 21st century. Scientists recently learned the eels hatch in the Sargasso Sea, a weedy expanse located between ocean currents off the East Coast. It wasn’t understood why some eels (Anguilla rostrata) migrate west to North America and others (Anguilla anguilla) migrate east to Europe. In a 2017 study co-authored by University of Pittsburgh biologist Jessica F. Stephenson, researchers used a ‘‘magnetic displacement’’
experiment that showed that the orientation of young eels varied in response to subtle differences in the Earth’s magnetic field intensity and other factors along their marine migration routes.
“These findings provide new insight into the migration ecology and recruitment dynamics of eels,” the study said. “[They] suggest that an adaptive magnetic map, tuned to large-scale features of ocean circulation, facilitates the vast oceanic migrations of the [European eel],”
American eels are common along the Atlantic and Gulf coasts. The Delaware River and its tributaries contain Pennsylvania’s largest population. Considering the size of Mr. St. Esprit’s eel, matching the largest found in the commonwealth, and its discovery in Northern waters, it was most likely a female. She took the long route from the Sargasso Sea to Pittsburgh, her tiny clear larval stage drifting eastward in the current around Florida and into the Caribbean Sea. As a juvenile, she entered the Mississippi River and navigated Ohio River dams, taking about a year to reach the river system’s headwaters.
Female eels generally spend 10 to 20 years in clearrunning streams, hiding under rocks and submerged logs. They are aggressive predators, scarfing aquatic insects, crayfish and other crustaceans, frogs and fish. Sometimes they’ll take an angler’s worm or bait, such as St. Esprit’s cut skipjack, a type of freshwater shad. Eels feed mostly at night.
Rarely seen, they appear to be slick and scaleless, but tiny scales are embedded in the skin. A long dorsal fin extends over two-thirds of its back. Below, the tail and anal fin are joined. American eels are yellow-brown to olive and lighter underneath. A long head tapers to a small mouth and beady eyes, and its lower jaw sticks out from under the upper mouth.
The number of American eels that survive migration is declining, but in Pennsylvania, they are not considered threatened. Although eels are not considered a game fish, the state Fish and Boat Commission manages the population with an open season, 9-inch minimum size and daily limit of 25.
In the fall, Mr. St. Esprit’s mature eel may be ready to begin the long migration back to the Sargasso Sea. In brackish tidewaters just off the Mississippi, she’ll hook up with smaller males, which don’t travel the full migration route. She’ll arrive in spawning waters carrying more than 2 million eggs. She’ll spawn and die, and the curious life cycle will begin again.