Alewives Return to the Penobscot,
But Who’s Counting?

by Catherine Schmitt

Pierce’s Pond, Penobscot, Maine. The Town of Penobscot has been working to establish a commercially harvestable run in the Bagaduce River. In the fall of 2017 two new rock-ramp fishways were completed at Pierce’s Pond and Wight’s Pond. Bailey Bowden, monitors the run in the watershed, which this year totaled nearly 500,000.

In the last twenty years, ten dams have been removed from the mainstem and tributaries of the Penobscot River by a variety of government, nonprofit, and private entities. There’s a riverine bypass channel around the dam at the mouth of the Piscataquis River in Howland. On smaller streams throughout the watershed, towns and land owners are replacing culverts to restore a full, uninterrupted flow of water and prevent flooding damage. Most of these projects were completed in the name of wild Atlantic salmon (an endangered species) and brook trout, as well as other migratory fish that move between freshwater and the sea—especially alewives.

Alewives have been a focus as efforts to restore the Penobscot watershed have intensified with the Penobscot River Restoration Project and now NOAA’s Habitat Focus Area designation. Alewives support commercial fisheries (for lobster bait) and are food for everything from other fish to mammals to birds. Alewives migrate through the river but ultimately they are destined for lakes and ponds, where they spawn and lay eggs; the hatched young spend one or a few months in still water before migrating out. Stocking lakes with alewives has proven effective at building new populations, as long as the fish have access to and from lake habitat. Scientists and managers and community members have installed “nature-like” rock ramps, or “pool-and-weir” fishways at the outlets of seven lakes and ponds; other lakes have technical fishways of metal or concrete.

The population of both alewives and (closely related blueback herring) in the Penobscot has increased from a few hundred thousand in 1998, mostly in the Orland River, to more than two million in 2018. At least, that is the number of river herring counted ascending the first dam on the river, between Milford and Old Town. Brookfield Renewable Energy tracks and reports fish numbers to the Maine Department of Marine Resource as part of conditions for their federal permit to generate electricity. Maine DMR, in turn, posts updates to the “trap count” section of their website.

However, no single entity maintains counts of migratory fish across the Penobscot watershed or across the state. Each alewife “run” has a different assemblage of people and organizations involved. The most closely monitored are those runs that are harvested commercially. Fishermen or town fish wardens are responsible for monitoring populations in order to comply with sustainability standards set by the Atlantic States Marine Fisheries Commission. Fish can be harvested for only some days a week; on the other days, fish are allowed to pass freely into lakes. The total number of fish harvested thus represents a proportion of the total population, which has to be maintained at a certain level (235 fish per acre of lake habitat). However, like other fisheries landings, commercial harvest numbers are considered proprietary, and kept private by DMR. According to Mike Brown of DMR, posted river herring counts are for the most part head of tide or lowest most dam counts. “Most all river herring counts are confidential harvester data designed to protect fishermen,” said Brown. “The best way to obtain count information is to contact us. We have and maintain current counts at 95 percent of the locations where counts occur.”

The Town of Penobscot has been working to establish a commercially harvestable run in the Bagaduce River. Last fall, two new rock-ramp fishways were completed at Pierce’s Pond and Wight’s Pond. Bailey Bowden, working with Maine Center for Coastal Fisheries, monitors the run in the watershed, which this year totaled nearly 500,000. “This is double what we have seen in years past, but our program started in 2015 and this is the year we should see big returns,” said Bowden. “My goal is to see a fully restored Bagaduce River that can support one million alewives returning annually.”

At Walker Pond in the headwaters of the Bagaduce, volunteers observe fish during windows of time, manually counting for a certain portion of each hour, providing a visual estimate of the population. Weirs and notches in dams force fish through a narrow point of entry. One or a few at a time, they slip upstream, and a volunteer records them with a click. Some fishways have cameras that record upstream passage for later viewing and counting; there are also electronic counters.

On Blackman Stream, where Atlantic Salmon Federation led an effort between 2009 and 2014 to install multiple fishways on the stream and lake outlets, more than half a million alewives returned this year.

On other Penobscot tributaries where dams were removed decades ago, data are more scarce. In the Sedgeunkedunk, where two old mill dams were removed and a rock-ramp fishway constructed, NOAA Fisheries monitored fish populations for several years—enough to show that salmon, eel, alewives, and lamprey moved into the new habitat. The osprey and eagles soaring overhead indicate that fish are migrating into Sedgeunkedunk Meadows, but there’s no official count.

Asked about run numbers in the Sedgeunkedunk, Ducktrap, and Souadabscook, Mitch Simpson of the Maine DMR responded, “We don’t have alewife run numbers for any of those tributaries, and I’m not aware of anyone that had collected them in the past.” Karen Cullen, town planner for Hampden, said that nobody in town government monitors the alewife run in the Souadabscook, and she was unaware of any local organizations. The town’s primary watershed-related activity is on stormwater management.

The two-million-plus total for the Penobscot River represents only those fish that traveled to habitat above Old Town. Adding in Blackman, Bagaduce, Orland, and Pushaw (those runs for which counts are available) pushes the total closer to three million—this is more fish in the river than at any time in at least the last one hundred years, but only a fraction of historic numbers or future potential. NOAA Fisheries is monitoring fish in the estuary, documenting the increased biomass and resulting changes in the food web, but has not yet published any results.

The Nature Conservancy is working with Maine DMR and Downeast Salmon Federation to bring increased coordination to data collection beyond the mainstem river fish counts. “We want to make sure someone is paying attention,” said Joshua Royte of The Nature Conservancy. “This is critically important to understand where some of these species have strong runs, weak runs, or populations of fish, like tomcod or rainbow smelt that have blinked out all together from any number of factors, including a warming Gulf of Maine. Our hope is that we can help develop an accessible database so anyone could check and see how any number of sea-run or diadromous fish migrations are doing in any one year, and compare it to other years. The current data DMR maintains are excellent, and I’m looking forward to increasing our knowledge of more of the state’s rivers and more species over time.”

In its 2008 Strategic Plan for Restoration of Diadromous Fishes to the Penobscot River, Maine Department of Marine Resources estimated that the watershed could support more than 18 million alewives. The implications of such an influx of forage fish for commercial groundfish, local wildlife, and river ecology remain unclear, but those who counted the fish in 2018—the ones who are paying attention—have witnessed their rivers once again alive with fish.