Pandora's Locks: The Opening of the Great Lakes-St. Lawrence Seaway

04/ ALEWIFE INVASION

55 55 I never saw such a mess in my life. —George F. Liddle, city manager of Muskegon, Mich., following an alewife die-off in 1966 04 ALEWIFE INVASION F or the better part of three centuries, anglers and fish-eating birds have converged on rivers in Canada’s Maritime Provinces each spring to stalk a small fish known to locals as gaspereau. It is an anadromous ocean fish, a type of herring known in the United States as alewife, river herring, or sawbelly. Technically, its name is Alosa pseudoharengus. But the common names afforded it are far more interesting. Some anglers call it sawbelly due to the row of scales along its belly that resemble a saw blade. Many Americans refer to it as alewife, a name some historians attributed to an early angler’s barmaid wife. Others claimed the fish was named alewife because the belly protruding from its slight frame resembled a beer gut. In the fishing villages of eastern Canada, the fish is known simply as gaspereau. It is a beloved species. 56 C H A P T E R 4 56 Every May or June, depending on water temperatures in the rivers, alewives vacate their saltwater havens in the Atlantic Ocean and headed for spawning grounds in freshwater streams. Measuring up to a foot long, the fish—silver, with a dark green stripe along their backs—swarmed into the rivers and streams that slice through New Brunswick, Nova Scotia, Prince Edward Island, and Newfoundland. Each female deposits as many as 100,000 eggs on river bottoms before heading back to sea for another year. The fish are an important bait species for larger ocean fish. They also provided an income for commercial anglers in the Maritime Provinces. Canadian anglers sold millions of dollars worth of gaspereau every year. Some became dinner for humans, but the majority were sold as fish bait and cat food.1 The fish’s annual spawning ritual occurred up and down the Atlantic seaboard, from Newfoundland to South Carolina. It was an event widely celebrated for its ecological significance, as well as its symbolic renewal of life on the heels of winter. There is little mystery surrounding the arrival of spring in the quaint Maine fishing village of Damariscotta. Migrating alewives usher in the season, attracting hundreds of visitors to the quiet coastal community of 2,000 residents. Locals and tourists flock to the banks of the Damariscotta River to watch massive schools of alewives migrate through the river’s estuary, into the Great Salt Bay and up a fish ladder that lifts the creatures into Damariscotta Lake. Thousands of fish congregate at various points in the journey, their masses forming moving clouds of fish beneath the water’s surface. Ospreys, herons, and bald eagles flock to the river for an easy meal. Birders converge on the river to see the majestic birds in action. It was fitting that alewives were celebrated in Damariscotta. The village name was a crude interpretation of the Algonquin word Madamescontee—a place of abundant alewives. The beloved ocean fish were not afforded a warm welcome when they arrived in the upper Great Lakes in the 1940s. They were greeted with all the ceremony afforded a disease, which was precisely what alewives were to the lakes. Through no fault of its own, the marine species found its way into the world’s largest freshwater ecosystem. And it was good, at least for alewife. The species was the beneficiary of human tinkering that opened the lakes to ocean species and knocked the freshwater ecosystems wildly off kilter. The chaos created dysfunctional predator-prey relationships that allowed alewife to become the dominant species in three of the five Great Lakes. That made 57 A L E W I F E I N V A S I O N 57 the alewife a scapegoat for humans who built the canals that allowed the foreign fish to conquer the lakes. Sea lamprey and alewife were the first ecologically significant fish species to invade the Great Lakes. Both arrived through the Welland Canal, the predecessor to the Seaway. The lamprey’s devastating effects on lake trout and other native fish populations were evident before the Seaway opened. The alewife’s effects remained largely unknown until the 1960s, when millions of the fish died and washed up on beaches. Despite their differences, sea lamprey and alewife were...