Lake Champlain Zooplankton Community Dynamics Following an Extreme Flood Event

Abstract

Lake Champlain, the sixth largest freshwater lake in the U.S., is a deep thermally stratified temperate zone lake system. Recently, flood events have impacted the Northeastern U.S. more frequently than in past decades, resulting in increased turbidity and other impacts in northern temperate lakes. This study represents an unprecedented analysis of the impacts of major spring and summer flooding in 2011 on Lake Champlain zooplankton communities. Few studies exist on flood impacts on lake systems, especially in natural un-impounded lakes. Our results illustrate the impacts of large-scale flooding on planktonic communities in deep stratified temperate lakes and the differential responses among species based on autecological traits. Community responses include flood-adapted increase during the flood event (Ceriodaphnia reticulata and Eubosmina coregoni), a flood-intolerant decline (Asplanchna spp. and Keratella cochlearis) or a delayed flood intolerance (Daphnia retrocurva, Mesocyclops edax, and Polyarthra spp.). Our results suggest that large, temperate lakes such as Lake Champlain will experience community shifts in zooplankton composition during future extreme flood events associated with climate change-related weather patterns in the Northeastern U.S.