Sipayik: Increasing mudflat productivity in Passamaquoddy Bay


Chris Johnson – Sipayik Environmental Department

short project summary (pdf)


The Passamaquoddy have harvested shellfish in their ancestral homeland for millennia. Today, harvesters at Sipayik, the peninsula at the confluence of Passamaquoddy and Cobscook Bays, are limited to harvesting on the peninsula’s two mudflats. Without access to town resident clamming licenses, clammers are unable to dig on neighboring flats where they have traditionally harvested for thousands of years.

The shellfish program is one facet of the Sipayik Environmental Department’s mission to enhance and protect tribal lands and human health. The department also supports programs related to water quality, brownfields, climate change, sea-run fish passage, and restoration of the St. Croix watershed. Staff at the Sipayik Environmental Department are trying to grow the shellfish program and develop an ordinance to re-establish fishing rights within Passamaquoddy homelands.

Map of the Passamaquoddy Homeland, produced by the Sipayik Environmental Department

Clam FarM

The population of soft-shell clams is decreasing in Half Moon Cove, one of the two mudflats at Sipayik. In an effort to supplement the flat with clams for community use, a partnership among the Sipayik Environmental Department, Downeast Fisheries Partnership, Downeast Institute, and Wabanaki REACH developed the idea for a clam farm. Communities on the West Coast—such as the Swinomish Tribe at Kukutali Preserve—have brought back clam gardens in recent years. Clam gardens in the Pacific Northwest are a traditional Indigenous practice, made by building rock wall terraces along beaches, which studies show doubled or even quadrupled the production of clams.

Chris Johnson of the Sipayik Environmental Department hosted meetings with clammers to gauge interest and plan the project. Bob Wood of the Downeast Fisheries Partnership helped secure a grant for the purchase of seed clams and nets. In May, 2022, the group set twenty plots of 14 ft. x 14 ft. nets in Half Moon Bay, with about 4,000 seed clams in each plot. A few plots without sets were also established to serve as controls. An additional twenty plots are planned for the fall. The nets will be removed at the end of the season and returned in the spring, and reseeding will occur each year of the project. When the clams reach a viable size, the area will open to community harvest.

Productivity and Settlement Projects

An ongoing mudflat productivity study, in partnership with the Downeast Institute, seeks to identify the sections of Half Moon and Gleason Coves with the highest settlement rates using Beal Boxes. This study has been ongoing for five years, and found that Gleason Cove has exceptionally high settlement; however, the cove is cleared out quickly when open to harvesting, and is often closed for years at a time.

In 2016, the Sipayik Environmental Department worked with Theo Willis of the University of Southern Maine on an experiment to test the efficacy of nets for clam survival. The Tribe engaged with a netting project in the 1990’s similar to the clam farm, but did not receive much community support at the time.

Half Moon Cove at high tide


The Sipayik Environmental Department is searching for a new hire for the shellfish program, which will grow staff capacity, and, paired with the eventual adoption of an ordinance, will help conserve and restore shellfish populations. This project has struggled with low harvester participation and hesitation around the idea of a clam farm. Fishing rights are not acknowledged, which creates ongoing issues for accessing clam flats. The Passamaquoddy Tribe at Sipayik is engaged with a number of issues related to human and environmental health—notably, a decades-long clean water crisis. This ongoing work of the shellfish program is one important piece of sustaining the community at Sipayik.  


  • 1990’s

    First netting project at Sipayik

  • 2016

    Study on viability of nets to increase clam survival

  • 2022

    Clam farm project: community meetings and net installation in Half Moon Cove

Volunteers in the foreground of the newly established clam farm at Half Moon Cove (Photo courtesy of Bob Wood)


Passamaquoddy Environmental Department

Schoodic Riverkeepers

Wabanaki Reach

Sipayik’s Water Crisis, StoryMap by Noela Altvater

“Clam Garden Will Bring History Full Circle at Kukutali,” Northwest Treaty Tribes

“How Indigenous Sea Gardens Produced Massive Amounts of Food for Millennia,” Hakai Magazine