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Ongoing Project: Silver Lake biomanipulation experiment

Lars Rudstam, Paul Simonin, Chris Hotaling, (Funded by the Rose Conservancy and the Actus Foundation) 

The research on alewife in a small lake in northern Pennsylvania investigates the interactions between alewife, zooplankton, and stocked brown and rainbow trout. With the help of citizen scientist Russ Cole, we collect data on the zooplankton and water clarity in Silver Lake and study the abundance, growth and condition of the alewife population. Rainbow and brown trout have been stocked into the lake intermittently since 2006 in an effort to control alewife and allow the lake to return to the higher water clarity observed in the 1990s. Unfortunately, alewives have continued to defy the predators and are still abundant in the lake. High alewife abundance is associated with small zooplankton and low water clarity in the lake, and this trend continued in 2015. Although we have not yet observed the intended outcome of the biomanipulation experiment, we do get valuable information on a dense slow growing alewife population in a mesotrophic lake.