Effect of Invasive Zooplankton on Lake Champlain Zooplankton Community Structure

Introduction

Lake Champlain

Cladocera: Daphnia retrocurva, Bosmina longirostris, Ceriodaphnia sp.

Copepoda: Diacyclops thomasi, Tropocyclops prasinus mexicanus, Leptodiaptomis sisilis

Rotifera: Asplanchna, Conochilus, Kellicottia, Keratella

Invasive predatory cladocerans: Bythotrephes longimanus and Cercopagis pengoi

Decline of cladocerans found within samples after spiny water flea invasion (Yan et al. 2002)

Zooplankton decline after spiny water flea invasion in the Great Lakes. a - Michigan, b - Huron, c - central and d - eastern Erie (Barbiero and Tuchman 2004)

Native zooplankton predator Leptodora kindtii

Methods

Lake Champlain map showing the location of the 5 study sites

LCRI research vessel: Greundling

Zooplankton sampling nets

Zooplankton identification key images showing anatomy of common species

Results

Example of species decline due to spiny and fishhook water flea

Example of species that appear less affected by spiny and fishhook water flea

Example of species with no change due to spiny and fishhook water flea

Average density of zooplankton (Cladoceran, Copepod, Rotifer) through the field season without invasive zooplankton (2012 to 2013)

Average zooplankton density after spiny water flea invasion (2014 to 2017)

Average Zooplankton density after fishhook water flea invasion (2018 and 2019)

CCA ordination plot of station 19 data for all years

MetaMDS ordination plot of spiny water flea invasion at station 19 (2013-2016)

MetaMDS ordination plot of fishhook water flea invasion at station 19 (2017-2019)

Conclusion (so far)

Spiny and fishhook water flea have caused reduction in the population of certain species, while others are largely unaffected.

References

Barbiero R, Tuchman M. 2004. Changes in the crustacean communities of Lakes Michigan, Huron, and Erie following the invasion of the predatory cladoceran Bythotrephes longimanus. Canadian journal of Fisheries and Aquatic Sciences 61: 2111-2125

Yan N, Girard R, Boudreau S. 2002. An introduced invertebrate predator (Bythotrephes) reduces zooplankton species richness. Ecology Letters 5: 481-485

Mihuc T, Dunlap F, Binggeli C, Myers L, Pershyn C, Groves A, Waring A. 2012. Long-term patterns in Lake Champlain’s zooplankton: 1992-2010. Journal of Great Lakes Research 38: 49-57

Appreciate