- Alliance to Protect Nantucket Sound
- Association to Preserve Cape Cod
- Back River Watershed Association
- Buzzards Bay Coaliton
- Cape Cod Commercial Fishermen's Alliance
- Cape Downwinders
- Community Action Works
- Eastham Conservation Foundation
- Edible South Shore & South Coast
- Eel River Watershed Association
- Environmental League of Massachusetts
- Forest Steward's Guild
- Green Burial Council
- Green Burial Massachusetts
- Jones River Watershed Association
- Manomet, Inc.
- Mass Audubon
- Mass Green Network
- Massachusetts Climate Action Network
- Mourning Dove Studio
- Neponset River Watershed Association
- New England Mountain Bike Association - Southeastern Massachusetts Chapter
- North & South Rivers Watershed Association
- Pegasus Foundation
- Pembroke Watershed Association
- Pilgrim Watch
- Plymouth League of Women Voters
- Public Employees for Environmental Responsibility
- Salicicola
- Salt Pond Areas Bird Sanctuaries
- Save the Bay - Narragansett Bay
- Southeastern Massachusetts Pine Barrens Alliance
- Six Ponds Improvement Association
- Sustainable South Shore
- Taunton River Watershed Alliance
- The Trustees of Reservations
- Union of Concerned Scientists
- Waquoit Bay Reserve Foundation
- Watershed Action Alliance of Southeastern Massachusetts
- Weir River Watershed Association
- Westport River Watershed Alliance
- Whale and Dolphin Conservation