American eel’s journey is an amazing one
“As long as the tide ebbed, eels were leaving the marshes and running out to sea. Thousands passed the lighthouse that night, on the first lap of a far sea journey. And as they passed through the surf and out to sea, so also they passed from human sight and almost from human knowledge.” Journey to the Sea, from “Under the Sea-Wind” by Rachel Carson
When I was about 10 years old, I spent two weeks with family and friends at a remote cabin at the head of Upper Pistol Lake in Maine. The lake is about 40 miles northeast of Bangor and 50 miles west of Machias and the Gulf of Maine. One early evening, my childhood friend Lisa and I rowed a short distance from the shore to fish for white perch.
The perch were not biting, and as we reeled in our lines Lisa screamed as she pulled from the water what looked like a three-foot-long snake. She held it in mid-air, dangling from the hook, and swung it onto the floor of the boat. The writhing creature had us scrambling, but we somehow managed to get a hold of the slimy fish, remove the hook from its mouth and return it to the depths of the lake.
That night was my first encounter with an American eel, one of the most fascinating creatures in New England, including here in The Last Green Valley. The reason I described the exact location of Upper Pistol Lake is important when you understand the amazing journey eels make to the ocean to spawn.
In Rachel Carson’s two essays, “Journey to the Sea” and “Return,” from her book “Under the Sea Wind,” she describes in detail the epic journey of a single 10-year-old female eel she calls “Anguilla” (after the Latin name for American eel – Anguilla rostrata). From a small pond in the hills of New England, down through winding forest streams, to larger rivers, over waterfalls and around dams and eventually to the coastal estuary, Anguilla makes the journey from hills to ocean. She then ventures thousands of miles to spawn in the warm waters of the Sargasso Sea in the middle of the North Atlantic between the West Indies and the Azores. It is a journey thousands of eels make each year.
It is only the female eel who travels from the inland lakes, ponds, rivers and streams to the coast. The male eels do not live inland, spending their early years in brackish marshes and estuaries, but they join the females on their journey to the Sargasso Sea. To fuel the long ocean swim the eels rely on their fat reserves. Their bodies change, with eyes doubling in size, becoming more sensitive to blue light to enhance their vision in the deep water. At their destination in the Sargasso Sea, females who successfully made the journey release an estimated 20-30 million eggs, which are fertilized by the males. Once they spawn, the adult eels die.
The eggs hatch on the surface of the ocean into tiny transparent leaf-shaped larvae that drift in the Gulf Stream, taking a year to reach the coast by which time the transparent larvae metamorphose into “glass eels.” Another transformation occurs as the glass eels turn gray to green-brown, into what are called “elvers” and grow to four inches in length. Soon they will seek out their juvenile and adult habitats. The females make the return journey of their mothers to inland freshwater habitat, where they will live for several years before the urge to return to the sea to spawn.
The eels do not necessarily return to the same areas where the parents grew up but are randomly deposited by the ocean currents and then swim to coastal habitat. In the United States, they can be found on the east coast from Maine to Florida and are common in the Gulf states. They make their way into the suitable habitat of the Mississippi River and become less common with greater distance from the ocean.
In New England and The Last Green Valley, we can find eels pretty much everywhere there is suitable habitat. They can be found up the 400 miles of the Connecticut River to Canada and from there spread out east and west through the upper New England states. Eels are tolerant of adverse water conditions and can live out of water for extended periods of time. This important characteristic aids their journey to and from the ocean with the need for wriggling up and around the many dams along our rivers.
Eels live in many of The Last Green Valley’s freshwater lakes and slow-moving streams and rivers. I have found them in the backwater areas of our larger rivers, usually behind the many large dams that cross the Quinebaug and Shetucket rivers. They prefer deep water and mud bottoms and feed mostly at night on small fish, insects, crustaceans, frogs and any animal matter they can locate. They have even been known to leave the water to search for frogs and small mammals such as mice in grassy wet meadows along the edges of the water.
According to the US Fish and Wildlife Service, “the American eel is the only species of freshwater eel found in North America. People have fished and farmed eels for thousands of years, but, until recent times, little was known about the eel’s complex life history. The species has survived multiple ice ages and seems to be equipped to withstand the cycles and fluctuations inherent in ocean dynamics.”
The Atlantic States Marine Fisheries Commission reports that as of 2017, eel populations in the United States are at historic lows, although it is difficult to truly assess the levels because of the eels’ wide distribution. The main threats to eels are pollution and changes to their environment, but historic overfishing and predation are also issues. The obstruction of dams has been a significant threat to them since the Colonial era and into the Industrial era. Hydro-electric generation and associated dams also greatly restrict the movement of migrating eels. Eel passage ladders have been installed at some dams and more need to be installed to ensure safe passage for the eels to and from their ocean spawning grounds.
It was more than 50 years ago on a summer night in Maine when I first encountered the American eel. I sometimes wonder if, after we removed the hook and slipped it back into the water, that eel made it from Upper Pistol Lake, down the small exit stream of the lake and all the way for 50-plus miles to the coastal estuary. Did “our” eel join the thousands of other eels and make it all the way to the warm waters of the Sargasso Sea? As a young boy, little did I know the amazing journey the eel would undertake to complete its circle of life and death.
We live in a beautiful place called The Last Green Valley. I hope you, too, find enjoyment and inspiration in the natural world around us. Join me and others as we explore, learn, appreciate, care for, enjoy and pass on this special place we call home.
Information for this column came from “Under the Sea Wind” by Rachel Carson, the US Fish and Wildlife Service, World Animal Foundation, and Connecticut Fish Finder and The Atlantic States Marine Fisheries Commission.
Bill Reid is the chief ranger of The Last Green Valley National Heritage Corridor and has lived in the region for more than 35 years. He can be reached at firstname.lastname@example.org.
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