30 Years of Plankton Monitoring in Lake Champlain: What have we learned?

The Lake Champlain Basin Program has conducted Long-Term Monitoring in Lake Champlain since the mid-1990s.   This includes water quality monitoring and biological monitoring focused on planktonic communities.  Long-term records (1992-present) for native zooplankton in Lake Champlain illustrate the impact of invasive species on community structure over the past three decades.  Zooplankton exhibited shifts in composition associated with invasive species, including a decline in rotifer and Mysid abundance in the mid-1990s, following invasion of zebra mussels (Dreissena polymorpha).  More recent community alterations can be attributed to invasion of the Alewife (Alosa pseudoharengus) in 2006-08, Spiny Waterflea (Bythotrephes longimanus) in 2014 and Fishhook waterflea (Cercopagis pengoi) in 2018.  These patterns represent major changes in community structure with potential implications for the Lake’s food web dynamics.   In addition, altered Diel Vertical Migration (DVM) behavior was observed in Lake Champlain following the Spiny Waterflea and Fishhook waterflea invasions.  We also detected a decline in Mysis diluviana abundance following the zebra mussel invasion in Lake Champlain along with changes in population size structure over the past 3 decades.   In addition, we compared phytoplankton community composition in Lake Champlain from 1970 to present demonstrating long-term shifts in composition of cyanobacteria and other taxa.  Patterns in Lake Champlain’s pelagic plankton communities illustrate the threat that invasive species and/or altered thermal regimes may pose to the ecological integrity of freshwater ecosystems.  

Presentation Preference: Standard Oral (12 Minutes)

Primary Presenter: Timothy Mihuc, SUNY Plattsburgh (mihuctb@plattsburgh.edu)

Authors:

Timothy Mihuc, SUNY Plattsburgh  (timothy.mihuc@plattsburgh.edu)