Abstract

We will investigate how small eutrophic embayments on Cape Cod with  restricted tidal flow and impaired water quality due to nutrient pollution respond to remediation. The  Little Pond system, located adjacent to Vineyard Sound in Falmouth MA, the focus of this study, is an  ideal test case. Beginning in 2016, nitrogen loading to the watershed of the Little Pond estuary was  dramatically reduced (~80% decline in N-inputs) as a result of the installation of a sanitary sewer  designed to divert 260,000 gallons of wastewater per day (~12,500 kg N/yr from 1400 homes) for  treatment outside the watershed. This major manipulation of an ecosystem presents a unique opportunity  to study recovery of eutrophic estuaries. 

We expect significant lags in the response of the Little Pond system to wastewater diversion due to:  (1) the legacy of contaminated groundwater already present in the aquifer that will continue to seep into  pond from the shore, and (2) ongoing internal loading caused by release of nitrogen from decay and  mineralization of organic matter in sediments. Furthermore, as a number of researchers have pointed out, ecosystem functioning and community structure in eutrophic systems may not return to its historical  baseline or pristine condition in a linear or predictable way (Duarte et al. 2009; McCrackin et al. 2017).