It is time to feel a bit of optimism regarding the impaired river systems across our state. In the past I have described the problems associated with more than 1,100 dams in Maine, most of which are poorly maintained and serve no commercial purpose. During the Industrial Revolution, many people viewed rivers as useful only to drive mills’ water wheels or as free sewage systems. Fortunately, attitudes are changing and more groups are mobilizing to rewrite the future of our watersheds.
The “canary in the coal mine” here might be the alewife, one of three fish sometimes referred to as river herring (along with blueback herring and shad). Historic reports claimed that alewives numbered in the billions from Florida to Maine, but as more dams restricted their spawning runs, the number of fish plummeted to the point where they were considered for listing under the Endangered Species Act. Pioneering dam removals and river cleanup actions in recent decades offered hope that fish populations might recover, so in 2019, the U.S. Environmental Protection Agency concluded that no listing of the alewife was warranted.
The name alewife is often reported to have originated with a corpulent female tavern keeper, but it may have roots in Native American language lost in time. Vernacular names for the fish include “sawbelly” and “kiack.” By any name, it is a powerhouse of a fish in terms of its importance to the ecological health of the waters it inhabits. Mostly silver in color, with a bronze head and gray-green upper body, it also carries large black spots behind the head, which help distinguish the fish. Adults may reach 16 inches and 1 pound, but most migrating fish are half that size.
The alewife is generally classed as an anadromous species, meaning it spends portions of its life in both fresh and salt water. This distinguishes the river herring species from the Atlantic herring, which lives only in the sea. However, some alewife populations are landlocked, inhabiting only fresh water.
Alewives gained considerable notoriety in the middle 20th century when they migrated through Ontario’s Welland Canal to bypass Niagara Falls and reach the upper Great Lakes. Here the fish overwhelmed many native species and then experienced a series of die-offs that left huge numbers of rotting fish along shorelines.
Lobstermen are delighted to have more alewives, since the fish is popular as bait. Managed harvesting is again allowed for both commercial and consumer purposes.
Human consumption was strong historically, since the fish was an easy source of protein and untold numbers were smoked for longer-term storage. Now we know the fish is a fine source of omega-3 fats, but you must be prepared to deal with numerous small bones.
A lingering concern is overharvesting while the alewife is at sea, where it has been found as far as 120 miles from shore. The National Oceanic and Atmospheric Administration is working with the fishing fleet to manage the harvest of all river herring, monitoring their locations and diverting fishing boats away from the fish.
The real value of alewives is their role in the food chains of the ocean and free-flowing rivers as they migrate 150 miles or more upstream to spawn in lakes, ponds and river backwaters. Untold millions of small fish equate to a huge bounty of stored energy that can feed not only threatened ocean species, such as whales, tuna, cod and striped bass, but also trout, salmon, black bears and otters. Spend time in May and June along Maine rivers with rising populations of alewives and you will be amazed at the concentration of bald eagles, ospreys, herring gulls and great blue herons. Each female alewife deposits tens of thousands of protein-rich eggs, most of which become food for a myriad of insects and aquatic creatures.
In July, the Bureau of Sea-Run Fisheries and Habitat at Maine’s Department of Marine Resources noted that several rivers saw strong runs of fish this year. At Benton Falls on the Sebasticook River, more than 6 million fish were logged. The Penobscot River count at Milford Dam reported 5 million fish. New federal funding of $70 million for dam removal and habitat improvement should allow this nascent recovery to continue.
Closer to home, members of Merrymeeting Bay Trout Unlimited are working with a coalition of conservation groups and state agencies to force Brunswick dam owner Brookfield to greatly improve its inadequate fish ladder. There is a long road ahead, but the alewives will respond with our help.
