Miramichi River watershed at approximately 13,400 sq km is too large in scale for comprehensive annual environmental monitoring. We thus divided the watershed into major sub-watersheds based on major tributary branches. For this project, MREAC normally selects a different sub-watershed each year to conduct environmental monitoring, involving general water chemistry at six or more sites during high and low water conditions. These samples are processed by the NB Department of Environment. Following sample collection and analysis, MREAC providesa report is written that presents the results. Some of these reports are available online under Publications.

This is a list of the sub-watersheds of the Miramichi River according to MREAC, with their area in square kilometers and study year:

Northwest Miramichi

• Little Southwest Miramichi (1,344 sq km)
• Northwest Miramichi (2,516 sq km) - 2007
• Millstream (210 sq km) - 2003

Southwest Miramichi

• Barnaby (490 sq km) - 2000
• Bartholomew (396 sq km) - 2000
• Cains (1,399 sq km) - 2002
• Renous (1,429 sq km) - 2006
• Southwest Miramichi (3,930 sq km)
• Taxis (510 sq km)

Main Branch / Estuary

• Baie St. Anne (181 sq km)
• Bartibog (512 sq km)
• Bay Du Vin (283 sq km)
• Napan (114 sq km) - 1998