2025 Nequasset Alewife Count
Photo by Joanne Adams
As the 2025 alewife count comes to a close, thank you to all the amazing volunteers who helped to document the number of fish that entered the lake this year! The second half of the alewife count had some days with large numbers of fish moving through and other days with very few fish at all. There were many great wildlife sightings.
Look below for:
A reminder to submit your data
Fun fish fact
Thank you for braving the rain this very wet spring!
Some great photos of birds visiting the Nequasset alewife run during the second half of the run
A graph of fish count data so far
Fish Counter observations
A list of the amazing volunteers who have taken part in the fish count
Please submit any remaining fish count data!
The fish count numbers are used by the town to sustainably manage the harvest, the Bath Water District to measure and improve the function of the fish ladder, the Maine Dept. of Marine Resources to study and manage fish populations around the state, and other groups who do local road and stream projects to make sure these projects don't harm fish.
Fun fact!
The name "river herring" refers to two types of fish: alewives and blueback herring.
They look very similar and have similar life histories, but alewives lay their eggs in ponds and lakes, and blueback herring lay their eggs in streams.
Report from Mike Brown, Fisheries Biologist at Maine Department of Marine Resources
Nequasset alewife scale samples reveal interesting information about the age of returning fish in 2023 and 2024
The volunteers counting fish and making environmental observations at the fish ladder provide information that may otherwise go uncollected. Counts of river herring climbing the fish ladder from the tidal Kennebec River into Nequasset Lake is one of the most important pieces of data that the Maine Department of Marine Resources uses in its annual assessment of the river herring population at Nequasset Lake.
In addition to the counting program, there is another sampling program that occurs concurrent with the counts that is also very important to determine the sustainability of the Nequasset river herring population. Biological data collection, conducted by the commercial harvester, provides information that cannot be determined by counting fish passing upstream through the fishway.
Each week, the commercial harvester collects scale samples from fish harvested below the dam. The Maine Department of Marine Resources uses these samples to determine the species, age, mortality, and reproductive history of the river herring population. Scales contain structures that allow scientists to determine how old a fish is at the time it is harvested. These structures are very similar to the growth rings you see when a tree is cut down, revealing annual growth of the tree.
Because environmental conditions and commercial harvest are variable each year, the spawning success of fish that enter Nequasset Lake is also variable. In some years spawning conditions may produce a lot of individual fish, while other years may not be as favorable. There are several factors that determine how many fish survive to a reproductive age and return to spawn (disease, bycatch in other ocean fisheries, predation). To evaluate the effects of these variables, the State monitors the age of fish that return each year to spawn. Each individual age class is called a cohort and each cohort represents reproductive potential for that year. Below is an example of the age classes observed at Nequasset in 2023 and 2024. The growth of the 4-year old fish sampled in 2023 is evident in 2024 as this cohort returns as 5-year old fish.
2019 was a good year for fish survival! It seems like the very high numbers of fish in last year's count were mostly due to good returns of 5 year old fish.
Wildlife at the Fish Ladder
Thank you to Joanne Adams for sharing these wonderful pictures of birds enjoying the Nequasset Lake alewife run this spring!
Fish Counts at Nequasset Fish Ladder
Right after the last update was sent on 5/15, the biggest day of this year's fish count occurred on 5/16. There were four evening counts greater than 300. The first report of fish going down the ladder was on 5/17. Numbers dropped back to low to moderate counts until there was another rush of fish the evening of 5/19. There were barely any fish counted from 5/21 - 5/26, potentially due to the combination of cold temperatures with highs in the low 50s and heavy rainfall on 5/23. Another pulse of fish made it into the lake on 5/27 and 5/28. Fish numbers have dropped off, and there have not been any fish counted since a small count the evening of 6/1.
Volunteer Observations at the Fish Ladder
5/15 - 6/5
5/15
- "Very quiet morning. Saw one blue heron. No signs of fish in fish way."
- "Watched a pair of loons dive for fish. It's amazing how long they can be under!"
- "Fish are working their way up the ladder! Many fish were harvested for bait/smoking while we were counting."
- "12 gulls siting on the dam. Really a fun count with 76 fish!!! What a difference an hour makes."
5/16
- "Water still flowing over most of the dam, no birds seen, plenty of fish downstream."
- "Beautiful Great Blue Heron swooping. Chatted with Steve."
- "So many! We were shocked! They went across in bursts."
- "Lots and lots of fish. It was sometimes hard to keep an accurate count, with multiple fish crossing at a time, and turbulent water from their splashing making it hard to detect them as they crossed. There was wide distribution of fish sizes. Seven or eight great blue herons enjoyed their all-you-can-eat buffet."
5/17
- "4 herring gulls present at dam. 1 loon also present in lake. 2 loons flew overhead during count."
- "Osprey caught a fish in the river below during count. One fish left the lake and entered the ladder during the count."
- "Some alewives were coming down the ladder - I don’t know if they turned around and went back up or not. No wildlife sightings except for a few seagulls flying around."
5/18
- "Weather indecisive! Both sunny and overcast. More movement as weather settled."
5/19
- "No bird activity, lots of fish in fishway."
- "Several gulls flying about and gathering on the dam. An osprey arrived during our counting and observed the scene from the top of a pine tree; it did not fish while we were there. Water level lower than last week and flowing less heavily. Even so, a couple of fish that made it into the lake were swept back onto the ladder. Smoke house open."
- "Strong current, water spilling across the concrete."
- "Variety of fish sizes, though most smaller than ones I saw earlier in the season. One eagle, two great blue herons, one loon, and lots of gulls."
5/20
- "Water high - covering dam- and strong. A few gulls, 1 loon, some fish schooling below top "v" board."
- "Highish tide; still good outflow, but a little less than we've been seeing. Windy. Quite a few fish in the harvest area and several circling around the last stage before exiting the ladder, but few actually making the final plunge into the lake. Three great blue herons, an osprey, a juvenile eagle, and a bird watcher."
5/21
- "Flushed about 10 great blue herons out of the trees around the ponds when I arrived. One osprey sitting in a tree below the dam on the opposite side of the river, took off and hovered near the dam but no fish around (upper fishway was empty)."
- "Seagulls remain in the area, & were joined by a cormorant at the top of the dam & an osprey flying overhead. A few alewives below the dam but not making their way to the ladder. Breezy."
- "Only 3 fish went thru though I did see several being tossed around in the last bin. No fish in any of the holding tanks in the ladder visible from the deck. Lots of heron high in trees on both sides of the gut & further down to the right & out of my sight line. I could hear eagles squabbling with one another in their high pitched voices. One osprey landed in the trees across from the fish house but quickly moved on. Cold!"
5/22
- "6 fishermen waiting but no alewives, osprey waiting in a tree top, tide coming in."
- "3-5? in the top section - one tried but was not successful! My cheering did not help! Fishermen had left; Harvester left right after I arrived; 3-6 gulls; Osprey was in its tree - watching the whole time. Pretty strong wind! Glad for warm jacket!"
- "Fish grouping but few entering. Lots of blue herons, a few ospreys and 2 eagles. Water running hard out."
5/23
- "No fish visible anywhere."
- "Several fish were at the top of the ladder swimming around, but never made it over. Water was very turbulent going over the ladder and the cement area was flooded for about 4 feet from the ladder. Wildlife observed : 4 heron flying overhead, and 2 osprey circling and waiting in trees."
5/24
- "No birds no fish, smoke house had a sign they'd been there twice with no fish."
- "The entire deck was covered with racing water and the water over the ladder was flowing extremely heavily and fast. There were no fish pooling at the bottom either, but there were plenty of birds, sea gulls, great blue herons, and an osprey fly-over."
5/25
- "No alewives in either of our 10-minute shifts. Water 1” deep on spillway. We saw 1 eagle and a loon."
- "High, fast moving water"
5/26
- "Beautiful, sunny day, but not a fish to be seen, upstream or down! About an inch of water was flowing over the dam. Between counts we saw a yellow warbler, black and white and a northern parula."
5/27
- "Medium tide, healthy outflow. Two herons and nine gulls. It was good to see fish again, in contrast to our last few countings. Ditto for the sun."
- "WOW"
5/28
- "2 loons in the lake, 1 Great Blue Heron."
- "Many fish in the ladder but slow to make it into the pond."
- "Birds on the roof above but no gulls or any others here. The fish are back & swimming strong into the pond. Sometimes on the way up they spring from one section to the next with splashes everywhere. An exciting night after some zero counts! The fish going through don't seem to be runbacks."
5/29
- "18 seagulls, 2 blue heron, 1 osprey"
- "A big school of little fish were at the sticks by the dam."
- "A bald eagle flew through. Many alewives going over the dam back out to sea, more leaving than entering. We saw a seagull fishing on the dam. He caught his lunch."
5/30
- "A few fish in the upper baffle."
6/1
- "There was a school of run backs at the top, schooling between the last v and the edge of the dam. Saw fish washed over the dam. Osprey calling in a tree for part of count."
6/2
- "Seagull present. Once saw a fish jump in the still water beside me."
6/3
- "Highish tide, good outflow. No alewives down below, either. A great blue heron, but not a gull in sight."
6/4
- "Hazy. 2 Heron as we arrived, one Osprey. Alewives schooling above the dam snapping at dragonflies. Several little perch went out and back in."
6/5
- "Tide was high, but going out; outflow was less than it's been lately. Three great blue herons (one on the dam), three gulls (one on the dam), and an eagle. Lots of fish jumping in the water right above the dam. Hazy."
- "Lots in the pond & in the cove. None reentering the ladder. A few going back across the dam. Heron everywhere. A few gulls & one kingfisher."
Thank you to the volunteers who have taken part in the fish count this year!
Amy Wesson, Ann Springhorn, Anne Schlitt, Annie Chang, Caleb Chang, Angelina Vo, Willow Guimaraes, Anthony Pono, Odin Pono, Nick Pono, Barbara West, Bettina Luescher, Carol Proctor, Sydney Perkins, Joey Flaherty, Eben Flaherty, Carol Rohl, Gordon Bok, Cheryl Swift, John Swift, Kathy Gravino, Morse High School Career Pathways Program (CPP), Morse High School Unified Program, Morse High School AP Environmental Studies class, Dagny St. John, Dave Harrison, Dorsey Harrison, David Ingmundson, Kathy Ingmundson, David Carpenter, Katherine Carpenter, Debbie Locke, Debora Keller, Doug Bertlesman, Don Marsh, Cindy Marsh, Kelly Lebel, Adam Lebel, Elise Straus-Bowers, Erika O, Evelyn Lennon, George Eastman, Lynette Eastman, Gina Snyder, Bo Garrison, Ginger Holland, Barry Holland, Abigail Holland, James Peavey, Jeff Wickham, Carrie Kuempel, Joan Newkirk, Kevin Shute, Joanne Adams, John Swenson, Jon Biehler, Karin Sadtler, Kate Ahalt, Gus Ahalt, Kathie Duncan, Kathleen Hanning, Donna Curry, Katie McShane, Kelin Underwood, Kristin Feindel, Larz von Huene, Bex Marmor, Laura Henry, Alexei Douhovnikoff, Lauren Cochenour, Leah Bauer, Leon Harkleroad, Cynthia Harkleroad, Linda Woodbury, Livy Glaubitz, Lori Benson, Maranda Nemeth, Mark Wallace, Sylvia Wallace, Megan Bendson, Brent Bendson, Finn Bendson, Lauren Cunningham, Will Cunningham, Aoife Cunninghim, Melinda Baxter, Michael Branca, Juniper Branca-Chamberlain, Mollie Sandock, Nancy Sferra, Pamela VanVolkenburgh, Derek VanVolkenburgh, Polly Weidhas, Rachel Strachan, Julius Strachan, Sebastian Strachan, Rebecca Abuza, Rue Brown, Sara King, Sean Marlin, Kelsey Keller, Shannon Yarbrough, Emmett Yarbrough, Moira Yarbrough, Steve Eagles, Sue Sergeant, Sue West, Will Broussard
Your donations make it possible for us to continue the annual Nequasset fish count and carry out a range of other conservation, education, and restoration programs in the Kennebec Estuary.