The study of the oxygen content in the water of the Ipswich River has been an ongoing volunteer effort since 1997 by the Ipswich River Watershed Assoc.  It has been showing that those monitoring sites downstream of large wetlands have lower oxygen than the other reaches of the river.  To explain this Dr. Will Wolheim from UNH studied Maple Meadow Brook in Wilmington and attributes this sag in dissolved oxygen to the “breathing” of bacteria in wetlands that consume the available oxygen. One influence that has not been ruled out is the effect of aquifers and groundwater recharge on oxygen in the river. This survey is an attempt to measure this influence.