Lower Mystic Lake is a meromictic lake, which means that the lake has a deep layer of water that rarely, if ever, mixes with its top waters. As a consequence, the sediments at the bottom of Lower Mystic Lake accumulate in annual layers (or varves) that have been nearly undisturbed for a thousand years. Such varves in meromictic lakes preserve an historical record something like tree rings do. In the case of Lower Mystic Lake, the varves have been used by Mark Besonen and his collaborators to study the historical incidence of hurricanes.
Although the Mystic Lakes are popular for swimming, sailing, and fishing, the Upper Mystic Lake suffers from contamination by arsenic and other heavy metals from the Aberjona River.
^Anonymous (2005). "Mysteries in the Muck", UMass Magazine Online, Fall 2005 issue. Online version retrieved May 1, 2008.
^Besonen, Mark R., Abbott, Mark B., Francus, Pierre and Bradley, Raymond S. (2006). "A 1,000-Year High-Resolution Hurricane Activity Record for the Boston Area", Gulf Coast Association of Geological Societies 2006 Convention, September 25–27, 2006, Lafayette, Louisiana.
^Senn, David B. and Hemond, Harold F. (2002). "Nitrate Controls on Iron and Arsenic in an Urban Lake", Science, June 28, 2002: Vol. 296. no. 5577, pp. 2373 - 2376.
^Inhof, Christina J. (1998). "Research Brief 32: Understanding the Physical Processes Involved in Metal Transport in the Upper Mystic Lake", Release Date: 28 October 1998, Superfund Basic Research Program.
^Rauch, S. Hermond, H. F., Ravizza, G. and Morrison, G. M. (2003). "Chronology of platinum accumulation in an urban lake", J. Phys. IV France, 107 (2003) page 1123.