Nishiotaki Dam fish ladder

Newly constructed fishway assists Alewife migration

Michigan 2022 seasonaldieoff

Seasonal die off of alewives wash ashore the beaches of Lake Michigan

Alewife 2021 Keystone Species

"remarkable and resilient"

Huron 2021 Native Trout

Efforts to control invasive fish leads to resurgence of native fish populations

Michigan 2018 Clear Water

Lake Michigan is losing nutrients

Alewife 2016 Spawn

Alewives spawn in Upstate NY tributary for first time in 85 years

Alewife 2013 Dam Removal

A new future for Alewives

Alewife 2010 Collapse

Populations at severe risk of collapse

Alewife 2006 Reintroduction

Conservation efforts aim to reintroduce alewife to the Bronx River

Alewife 1950 2000 Decline

Average catch declines 98 percent

Alewife 1976 Conservation Management Act

The Magnuson-Stevens Fishery Conservation and Management Act

Michigan 1967 Algae bloom

A bloom of toxic algae kills millions of alewives

Alewife 1965 Plague

A plague of alewives

Alewife 1950s Population Peak

Populations peaked and swiftly declined

hist-5555-photo-Decline in Numbers Due to Dams and Pollution

Decline in numbers due to dams and pollution

Alewife 1827 somanyfish

So many fish that waters ran silver

Alewife 1800s Demand

Demand for alewives

Alewife 1729 Sawmill

Sawmills block Alewife migration

Alewife 1680s Dam construction

Dam construction blocks Alewife migration routes

Alewife 1637 Fertilizer

Alewives used as fertilizer for centuries

Alewife 1634 Ten thousand

"ten thousand taken in two houres"

Alewife 1600s abundant

Alewife abundant and has many uses

Alewife 1350 Gaspereau

Gaspereau fishing has been important to human settlement of the Gaspereau Valley for thousands of years

Alewives

Dam Construction 

Alewives spawn in the northern waters of Newfoundland, and later swim as far as South Carolina as they mature. In their lifetime, they may return north as many as eight successive times to spawn themselves. Since the late 17th century, their migratory routes have been blocked by dam and mill construction. These structures threaten the safety of the small fish as they attempt to pass through. Populations have disappeared completely from waters with long time dam structures present. Newly constructed fish ladders give some hope to the future sustainability of alewife populations, allowing them to safely bypass the dams. 

Toxic algae in the Great Lakes

Alewives entered the Great Lakes after the construction of the Welland Canal in 1931. By 1965, 90% of the weight of all fish present in the Great Lakes was made up of alewives, as reported by the Michigan Department of Natural Resources. This profusion, primarily in Lake Huron and Lake Michigan, disrupted the health of both deep water and shoreline ecosystems. Since the late 1960s, the water’s lack of nutrients and toxic algae blooms have caused extreme seasonal alewife die offs, with millions of fish washing ashore each summer. These occurrences presently continue, and truck loads of fish are carted to landfills yearly.  

Absence from native waters

As Alewife migration routes have been blocked by dam construction, and shoreline industries have contributed to runoff pollution, the fish has been fully absent from some of its native waters. As a keystone species, other birds, mammals, and insects suffer from the absence of the alewife. Efforts are underway to reintroduce populations to notable waterways such as the Bronx and Hudson rivers. As dams are removed, ladders are constructed, and fish are transplanted by the hundreds, there is hope for alewives to once again thrive in their native waters, and support their dependent flora and fauna. 

Most Pressing Issues

The Bronx River Alliance

The Bronx River Alliance works to protect, improve, and restore the Bronx River corridor. They were key in the construction of a fish ladder at the historic dam at River Park and have made numerous efforts to restock the river’s Alewife population. The Alliance is supported by its members, volunteers, and donors. 

The Mystic River Watershed Association

The Mystic River Watershed Association has worked to protect and restore the Mystic River since 1972. The association hosts a volunteer-run bucket brigade to hoist migratory Alewives over the Mystic River dam each year. Community members are encouraged to participate and learn about the remarkable species. The size of the annual run is in part accounted for by volunteers between the months of April and June. Recruitment begins in February, and all are welcome to apply. 

Alewife Harvesters of Maine

Alewife Harvesters of Maine is composed of fishermen, conservationists, biologists, and environmental advocates focused on conserving and preserving Alewife populations. The organization works with harvesters to maintain and improve harvest plans in accordance with historic and new runs. 

How you can help