Shellfish Projects

Moneskatik (Ma-na-ska-deeg) translates to clam place, literally the places where clams are dug in the Passamaquoddy Maliseet languages. It also used to reference the area now known as Bar Harbor. The Maine coast has many clam places, both past and present and this page features stories about people and their relationships with these clam places. We are still adding to these stories and profiles, so please reach out if you have additions or would like to work with us to include a description for your project.

Current featured projects include: Bar Harbor, Bristol, Damariscotta, Deer Isle and Stonington, East Machias, Freeport, Georgetown, Gouldsboro, Islesboro, the Soft-shell clam recruitment monitoring network, and Surry.

Bar Harbor: Clam population enhancement

In Bar Harbor, the shellfish committee along with collaborators from College of the Atlantic, Acadia Aqua Farms, Bar Harbor Oyster, Sweet Pea Farm, Maine Coast Heritage Trust and Maine Sea Grant are working to increase clam densities in Bar Harbor’s clam flats. Over the last few years, Bar Harbor has seen a decline in wild clam populations and an increase in green crab predation. To combat this, the group is using two techniques, first transplanting quahogs which are less susceptible to green crab predation, and second, putting up nets to restrict predator access.

To start, the group will be using recruitment boxes to determine possible clam densities, and collect spat. Spat will then be grown out in lantern nets at multiple aquaculture sites. Finally, after the grow out period, certain mudflats will be reseeded, with a proportion protected from predation. 

For more information please contact the project coordinator, Scott Swann at sswann@coa.edu.

Bristol : DNA testing to determine the source of contamination of the Pemaquid River

The Pemaquid river has 499 acres of harvestable clam resources that frequently close every summer due to high P90 scores. Initial funding from the U.S. EPA was able to determine point source pollution but was not able to identify a source. Bristol is taking two steps to remedy the water pollution issues in this area. One, they are using the MSRRF grant to do additional water testing to determine the source of pollution. Two, they are introducing Oysters to diversity shellfish resources and provide another way of alleviating water pollution. The movement of oysters will be done through the DMR’s Shellfish Transplant program. Bristol hopes their duel approach of improving the overall health and diversity of shellfish resources in this area can be modeled for other areas in Maine.

For more information on this project, please contact Rachel Bizarro at rbizarro@bristolmaine.org, or David Cheney at johnsriveroyster@tidewater.net.

Damariscotta: Assessment of shellfish resource for coastal resilience

The Damariscotta and Sheepscot Rivers in Maine midcoast region that is home to unique systems whose tidewater flats support a variety of soft shell clams. The surrounding areas rely on shellfish income year-round. Unfortunately, there is not resources to conduct population surveys, leading the Shellfish Committee and towns of Damariscotta and Newcastle to update shellfish management without an update of data. On top of this local managers are also affected by the lack of geographically specific historical data.

To better understand the current state of shellfish populations in the Damariscotta River and Medomak River estuaries, this group conducted shellfish population surveys, recruitment experiments, and interviewed local harvesters. This effort, finished in 2019, set up their current project, designing new shellfish resource assessments that are representative of historic ecological, social, and economic trends.

For more information, please email the project coordinator, Matt Lutkus at townmanager@damariscottame.com.

Deer Isle and Stonington: Water quality testing to re-open clam flats

A section in the town has had to remain close since 2014 due to the town not being able to find the source of the pollution. Additionally, a portion of Crockett Cove is closed due to the possibility of upstream beaver dam. In order to solve the root of these problems DNA testing can help in determining. This issue is of importance because long Cove’s clam flats are on of the main clamming areas on the island with clamming having a large impact on the economy. The goal of Deer Isle-Stonington Shellfish Conservation Committee is to have sustainable commercial shellfish harvesting so that those who do harvest can make a good living.

For more information, please contact George Powell at gthomaspowell@gmail.com.

East Machias: Identify the source of contaminating coliforms on clam flats

Since 2005, bacterial pollution has closed flats in the Town of East Machias. Currently, there are over 1,000 acres closed to harvesting between the towns of Machias and East Machias and no locally licensed clam harvesters. To better understand potential pollution sources, as well as provide more data to the Department of Marine Resources, the Town of East Machias has started to investigate these pollution sources. The group used specific DNA water tests that identify the source(s) of contamination whenever possible.These tests distinguish between small mammals, humans, cows, and birds. Information from these tests can then guide further remediation efforts to stop incoming pollution. The Town of East Machias is working closely with the University of Maine Machias to run the tests and analyze the information. 

This work has many possible benefits. Along with identifying potential sources, the Town of East Machias hopes to use this work as a first step in adopting a new local shellfish ordinance. This would increase the licenses available to clammers (who would no longer have to buy out of town licenses nearby) and possibly provide opportunities for collaboration. Historically, the Town of East Machias has had enough seed to sell to other communities to support conservation programs as well as support 20-30 local clammers. If a new town ordinance is adopted, local clam diggers could harvest this seed to share with other coastal communities. The project had delays due to COVID-19 and shipping restrictions, but water sampling will be underway in the coming months. 
To learn more about this project, please contact Kevin Brodie at whiting.cheif290@gmail.com, Bucket Davis at emclerk@roadrunner.com, or Dr. Sherrie Sprangers at ssprange@maine.edu.

Freeport: Sustaining shoreline access for shellfish harvesting

Freeport: There are 2700 acres of clam resources that rely on shoreline entry points, which have not been assessed since the 1980’s. Shoreline access has changed considerably since then and this project addressed this need through accessing all prior established access points and then re-mapping shoreline access points in relation to current shellfish resources. This collaboration worked closely with harvesters, landowners, shellfish committee members, natural resource managers, and a Marine Resource Officer to meet these objectives and support the 55 commercial and 33 recreational harvesters in this region.

For more information on this project, please contact Charles Tetreau at ctetreau@freeportmaine.com.

Freeport: Exploring the effects of winter harvesting closures for Northern Quahogs (Mercenaria mercenaria)

The Town of Freeport, along with many other shellfish communities, have increased their dependence on the quahog fishery, particularly as soft-shell clam populations have declined. In the context of these declines, quahogs provide an important source of income for harvesters. Scientific research highlights that quahogs are sensitive to cold temperatures and it has been observed anecdotally that winter harvesting closures may increase local populations of quahogs. With the growing interest in quahogs in Maine, this study presents initial insights into the topic.

This group focused on determining if digging during freezing temperatures had an effect on quahog mortality, thus exploring the effectiveness of winter harvesting closures on a municipal level. To do this, the group established a study area in Staples Cove in Freeport, Maine. The objectives of this study include: 1) assess feasibility of transplanting quahogs within the same cove; 2) understand the implications of this work among local harvesters, and local and state shellfish managers; 3) generate preliminary field data on mortality of quahogs from winter disturbance at a single site; and 4) test field methodology to refine for potential future studies with larger scale and geographic scope.

As this was a small-scale pilot study in one site, a need exists for larger studies in other locations of the state to help determine if these findings are consistent. Additionally, COVID-19 delayed the final field work in spring of 2020, so it is unknown whether leaving the quahogs in the study site for an additional month affected the results. Within this test site, this study observed that quahogs that were undisturbed (i.e., left alone in the mud) survive at a higher rate than those that were disturbed (i.e., dug and brought to the surface) during the winter. As a secondary finding, Staples Cove had a moderate success rate for transplanted quahogs of various sizes during the first six months.

For more information on this project, please contact Jessica Joyce, Project Manager, at jessica@tidalbayconsulting.com, or Charles Tetreau, Marine Resource Officer, at ctetreau@freeportmaine.com or, review the project report, here

Georgetown: Diversifying Georgetown’s shellfish resilience

More than 80 people in the communities of Bath, West Bath, Woolwich, and Georgetown own commercial licenses that help them make some or all of their income. These communities also sell a significant number of recreational licenses that bring in a tourist market. But due to clam flat closures due to water pollination and a decrease in harvestable clams due to predation has created a large problem that the shellfish communities can not handle at this present time.

To address this, the Georgetown shellfish committee is working with Manomet and Ipswich Shellfish to transplant adult quahogs into Robinhood Cove. First, the shellfish committee created a conservation closure on the harvesting of all quahogs in Georgetown. Dr. Marisa McMahan, from Manomet, created plots in Robinhood Cove to record the survival and reproduction of transplanted quahogs. Further research using Beal boxes was also conducted to understand the quantities of quahog seeds that are settling.

For more information, please contact the project coordinator, Charles Moore at gottscove@icloud.com.

Gouldsboro: Development and study of supports for municipal seed clam production

Many communities across Maine’s coast are working to seed or revitalize “dead” mud. This usually is a mixed methods process, where clams are protected from predators, and communities purchase large amounts of 1-year old seed clams from hatcheries like the Downeast Institute to place in these flats. Gouldsboro has previously used similar techniques to restore flats in Jones Cove, Joy Bay, and John Small Cove. 

This year, Gouldsboro is piloting a new method to reduce costs for coastal communities to buy seed clams. Specifically, Gouldsboro will assume responsibility for clam growth and survival at 2-3 weeks old, grow the clams out by overwintering them locally at a shoreline property, and then distributing them on the flats. Currently, they are in the process of building the overwintering facility, having already bought the 2-3 week old clams. During this study Gouldsboro is also using recruitment boxes to harvest wild seed to supplement their purchase.

For more information about this project, please contact Mike Pinkham, the Gouldsboro shellfish warden, at m73ap@yahoo.com, Bill Zoellick at bzoellick@schoodicinstitute.org, or Kyle Pepperman at kyle.pepperman@downeastinstitute.org.

Islesboro Soft-shell clam restoration project

The town of Islesboro is working to restore the commercial harvest of soft-shell clams in their area. Previous conservation and seeding efforts had not produced noticeable improvement in soft-shell clam numbers, however recruitment box studies in the area have shown there are extensive juvenile clams floating in the water.

This year, the Islesboro Shellfish Conservation Committee, along with members of the Downeast Institute and the Islesboro Central School is working to protect native clams from predation in the hopes to expand small scale efforts to commercial levels. The primary goal of this project is to return overwintered 1 year old clams to the mudflats within predator protection nets. The second goal of this project is to highlight the economic benefits from having a commercial harvest of soft-shell clams. To do this, the group is building two types of recruitment boxes to place juvenile clams in and distribute along the flats, as well as reseed clams under 14 ft. x 14 ft. nets. The first is the standard box with flexible mesh on the top and bottom to protect clams from predators above and below. The second will have a biofilm fabric or burlap bottom that will dissolve away, leaving clams on the mud but still relatively protected from predators by the remaining box. Depending on the results from this study, each type will be left to overwinter, and be retrieved in 2021. 

For more information please contact Janis Petzel, the project coordinator at petzeljanis@hotmail.com.

Soft-shell clam recruitment monitoring network

In 2020, the Downeast Institute (DEI) and University of Maine at Machias (UMM) partnered with nine community shellfish programs Sipayik to Wells to establish the Soft-shell Clam Recruitment Monitoring Network. The network currently consists of 18 monitoring sites (two in each community) that measure densities of soft-shell clams recruiting to mudflats. Analysis of the amount of recruitment and recruit survival rate help to better understand local, regional, and coastwide trends in clam production. The Network standardizes clam recruitment data collection and begins to build a long-term database. The information generated from the monitoring network may inform new measures to better manage the soft-shell clam resource.

These are the major sites for the Soft-shell clam monitoring network. Image provided by Sara Randall at DEI.

The Network is based on a deep understanding of clam biology and ecology. Specifically, each of the 18 monitoring stations are composed of sixteen 1-ft x 2-ft x3-in deep wooden-framed “Beal Boxes,” which are deployed in the lower mid-intertidal gradient before the beginning of the clam spawning season. Small mesh on the top and bottom of the boxes protect the clams that settle into them from most predators. Protected from predators, clam recruits are able to survive and grow throughout the summer and fall. Scientists and community members retrieve the boxes in late October and early November (after clam settlement has ceased) and take 6-inch deep and 6-inch diameter samples of the adjacent mudflats in the late fall. The contents of the boxes and the samples  are processed through a 1mm mesh sieve and the number of recruits are counted and recorded. Determining the number of recruits inside the boxes shows us how many juvenile clams settled out during the season at that site. Comparing those numbers to the number per square foot and size distribution found in the samples from outside the boxes provides and understanding of  how many clam recruits are able to survive into adulthood at that location, providing information about how or why a clam flat is commercially productive. For more information on clam biology or ecology, please visit our Clam Ecology page

Primarily, the soft-shell clam monitoring network uses recruitment boxes to measure the productivity of clam flats. Image provided by Sara Randall, DEI.

The overarching goals of the Soft-Shell Clam Recruitment Monitoring Network are to: 1) Increase visibility and public awareness of a fishery that is threatened by a dramatically changing marine environment; 2) Create an extensive data set for shellfish managers to better understand factors that affect the fishery; and, 3) Encourage participation and learning by coastal residents including clammers, shellfish committee members, and other municipal officials as well as K-12 grade students, their teachers and parents. 

For more information about this project please contact Dr. Brian Beal at bbeal@maine.edu, Sara Randall at srandall@downeastinstitute.org, or review the first technical report which details the results of baseline clam surveys at all 18 sites, which you can find here

Surry: Patten Bay pollution and shellfish stock assessment

Patten Bay in the town of Surry, ME has been closed to shellfish harvesting due to water quality pollution problems for decades. This year, the Town of Surry has collaborated with the Department of Marine Resources (DMR), the Department of Environmental Protection (DEP), the Shaw Institute and others to assess seeding, predation, and find and fix pollution sources impacting their shellfish resource. 

The town has taken a two pronged approach to this broad assessment. First, they are working with the DEP and DMR to coordinate a shoreline survey and water quality monitoring effort. This will include walking shorelines, mapping any potential sources, and then testing water samples using ColilertTM test kits. Second, they will be monitoring shellfish resources in Patten Bay, using recruitment boxes and predator box traps. Additionally, the Shaw Institute is providing interns to identify phytoplankton species and collaborate with DMR’s monitoring of Harmful Algal Blooms. 

For more information about this project, please contact Heather Richard at hrichard@shawinstitute.org.