April 9, 2024 — Anadromous fisheries require healthy watersheds, and while the Pebble Mine controversy in Alaska has driven home that point, on the other side of the country, Canadian and US entities are seeing positive results from the largest river restoration project on the East Coast. The International St. Croix River Watershed Board (ISCRWB) has been removing dams and building fishways along the border waters of the St. Croix River to restore alewife runs.
In 1987 more than 2.6 million alewives ascended the St. Croix River and dispersed into its various feeder streams. But that same year, at the urging of recreational fishermen concerned about the alewives eating bass eggs, the state of Maine ordered the closure of fish passages at the Vanceboro Dam, followed by closure of the Grand Falls Dam in 1991, and the Woodland Dam in 1995. By 2001 only 900 alewives entered the river.
The blocking of the alewife runs coincided with the decline of the cod and blackback (winter flounder) fisheries in the estuary of the St. Croix. Ted Ames, a fisherman and academic, won a MacArthur fellowship in 2005 for his analysis of years of survey data that showed alewives and cod present in inshore cod spawning grounds at the same time of year. “The cod would come inshore in the fall to spawn at the same time these young of the year alewives and herring were coming down,” said Ames. “It’s believed that the three-year-old cod were feeding on those small alewives. And there’s a correlation between the collapse of the alewives and inshore herring and the collapse of these cod spawning grounds. Spencer Baird was saying this back in the 1800s. If you dam these rivers you will kill the inshore fish stocks. The cod aren’t going to come in if there’s nothing in the dinner pail.”