Zebra and Quagga Mussels Reduce Native Benthic Macroinvertebrate and Microphyte Biodiversity: A case study investigating the impacts invasive dreissenids are having on the macroinvertebrate and macrophyte communities of Otsego Lake, NY

Abstract

This study investigated impacts the zebra (Dreissena polymorpha) and quagga mussel (Dreissena rostriformis bugensis) invasion are having on the macroinvertebrate and aquatic macrophyte components of the benthic community in Otsego Lake. Study attempts to replicate both macroinvertebrate and macrophyte studies previously collected on the lake's pre-invasion to contribute to a growing long-term data set. Summer of 2021 39 benthic macroinvertebrate samples were collected and compared to samples collected at the same depths in 1968 and 1993. 65 macrophyte samples were collected in littoral depths and compared to the 7 studies performed between 1935 and 2012. Observations indicate that, since the dreissenid invasion, there is an increased relative biomass of mollusk species in deeper water substrates, and significant declines in total species richness of macrophytes lake wide as well as frequency and distributional changes for certain species. Zebra and quagga mussels are having a definable impact on the lake's benthic community in dimensions predicted by the literature. Further study is needed to aid water resource managers and help them effectively mitigate the ecologically detrimental spread of zebra and quagga mussels.