Anthropocene History of an Urban Lake Worcester, Massachusetts

Reservoirs provide habitats for organisms, drinking water, and recreation space. Reservoirs are impacted by a variety of human and natural changes, which are recorded in sediments that accumulate within them. Patch Reservoir, Worcester Massachusetts, was created in the late 1800s and is an important local water body. Patch Reservoir has recently experienced significant eutrophication challenges related to accelerated sediment infilling. It is not well understood what has caused this acceleration, but recent construction in the watershed as well as beaver activity may have played a role. To determine the influences on sedimentation in this reservoir, we took several sediment cores from a small delta on the northern margin of the lake; analyzed their physical properties using visual core descriptions, magnetic susceptibility, and carbon measurements; and determined age estimates for notable stratigraphic changes using radioisotope data. We compare the results from this sediment core analysis to historical information compiled from a variety of sources including historic newspaper clippings and aerial photographs to show that flooding and watershed construction in the mid 1900s, and then beaver dam construction in the early 2000s are correlated with changes in sedimentation in the lake. Understanding how humans, climate and weather events, and organisms alter our landscapes can help improve mitigation measures to ensure that our communities are more resilient to future changes and impacts.