MACAN's Monitoring Plan Work Group (MPWG) is a sub-group within MACAN working to develop a monitoring plan to help in understanding the trends of regional acidification that can be used as a framework for focusing monitoring efforts. The MPWG focuses on monitoring from estuaries, to coasts, to open ocean. This webinar, held 3/6/18, provided the MACAN membership with an update on the progress of work done since September 2017.