Four years after one of the main fish ladders on the St. Croix River was reopened following a 19-year closure, the alewife run on the river increased significantly this year, jumping nearly fivefold from last year's run. A total of 157,750 alewives ended up being counted at the research trap on the Milltown dam fishway, while last year only 33,016 were counted. The average over the past 10 years is 47,142.
Heather Almeda, executive director of the St. Croix International Waterway Commission, states, "Dams, roads, climate change, overfishing and other human influences have led to decreases in historic river herring populations. River herring will first return to their natal river to spawn between ages 3‑5; four years ago the fishway at the Grand Falls dam was reopened, having been closed for nearly 20 years. The offspring born in 2013 would be expected to return to spawn in 2017, which may suggest why the St. Croix International Waterway Commission recorded a significant increase in the river herring population in 2017."
Alewives had been prevented from returning to 98% of their historic spawning grounds in the St. Croix watershed after the fish ladders at the Grand Falls and Woodland dams had been closed by the state in 1995. After the closures, the run on the St. Croix had plummeted -- from 2.6 million in 1987 to 900 in 2002. The fish ladders had been closed because inland sport fishing guides feared the alewives would harm the smallmouth bass populations in the region's lakes and ponds. The reopening of the fish ladders, first at the Woodland dam in 2008 and then at the Grand Falls dam in 2013, gained broad support after research demonstrated that smallmouth bass and alewives can coexist in lakes and waterways throughout Maine and the east coast of North America.
The turning point in generating support for reopening the river to alewives had been achieved by the Schoodic Riverkeepers, who had highlighted the alewives' plight by producing a video and holding a 100-mile sacred run in June 2012. In his testimony in favor of the 2013 legislative bill to reopen the Grand Falls dam fishway, which was sponsored by Passamaquoddy Rep. Madonna Soctomah, tribal member Brian Altvater Sr. of Pleasant Point, founder of the Schoodic Riverkeepers, stated that for thousands of years the alewives "would make their journey from the sea up to the St. Croix River to access the many lakes and streams to spawn in the waters of their ancestral homeland, returning vital nutrients from the ocean to these freshwater lakes and streams. Alewives once numbered in the tens of millions in the St. Croix River but now have been reduced to around 30,000, with an uncertain future." Noting that the alewife "is the fish that feeds all," he said its return would help bring back other fish that were once numerous, and he urged allowing them unrestricted access above the Grand Falls dam.
Reestablishing a healthy alewife run in the St. Croix watershed is expected to benefit both freshwater and marine ecosystems and other species that depend on them for food, including groundfish, Atlantic salmon, cod, ospreys and eagles. The alewife is considered a keystone species that is critical as forage for other species, which helps support coastal and inland fisheries. Alewives also are a local source of bait that helps offset the limited bait supply for the state's lobster industry. A conservative estimate of the economic benefits of reopening the St. Croix fish ladders and rebuilding its alewife run is between $3.1 million to $5.9 million, which would be derived from the reestablishment of a bait fishery alone.