An Historical Account of Water Quality Changes in Candlewood Lake, Connecticut, Over a Sixty Year Period Using Paleolimnology and Ten Years of Monitoring Data

ABSTRACT

A paleolimnological study was used in conjunction with ten years of monitoring data to assess the timing and magnitude of historical water quality changes in Candlewood Lake, a large pumped-storage reservoir in western Connecticut, USA. The paleolimnological aspect of the study supported much of the current literature on both reservoir development and die effects of land-use alterations of watersheds on waterbodies. Water quality trends gleaned from the monitoring database confirmed recent conditions inferred from fossil assemblages. Monitoring data also provided evidence supporting an improvement in trophic conditions beginning around 1988, but a continued increase in dissolved salt levels. The paleolimnological study and die long-term monitoring effort complemented each other in that the former provided quantitative insight beyond die temporal scope of monitoring, while die resolution of die latter enabled managers to assess effective strategies.

Key Words:

• paleolimnology
• long-term monitoring
• scaled chrysophytes
• diatoms
• productivity
• conductivity
• land-use