Abstract
Lakes and reservoirs play key roles in global carbon cycling, especially as a carbon sink. Enrichment of nutrients in lakes and reservoirs (eutrophication) and rising global temperatures favors the proliferation of bloom-forming cyanobacteria. Harmful blooms of cyanobacteria (cyanoHABs) alter carbon and nutrient cycling in freshwater ecosystems. Some evidence suggests the introduction or establishment of invasive mussel species (i.e., Dreissena spp.) also favor cyanoHAB formation through selective filter feeding, a process through which they may also impact biogeochemical processes including carbon cycling and sequestration. However, few studies have considered the combined effects of invasive mussels and cyanoHABs on carbon and nitrogen cycling in freshwater ecosystems. Here, we examined microbial community composition and biogeochemical attributes (including carbon and nitrogen stable isotopes) in eutrophic lakes, reservoirs, and rivers in western Ohio, eastern Indiana, and northern Kentucky during the cyanobacterial bloom period of the summer of 2015. Our samples include both sites impacted by invasive mussels and those where invasive mussels have not yet been observed. Based on 16S and 18S rRNA gene sequence analysis, we found that cyanobacterial and algal communities varied across sites and were most closely related to habitat (sediment or water column sample) and site, regardless of the presence of invasive mussels or other environmental factors. However, we did find evidence that invasive mussels may influence both carbon and nitrogen cycling. While the results are based on a single time point sampling, they highlight the interactions of multiple environmental stressors in aquatic ecosystems and the critical need for more temporally intensive studies of carbon and nutrient cycling in bloom- and mussel-impacted waters.
Highlights
Nutrient enrichment, a leading cause of eutrophication in freshwater ecosystems, leads to the proliferation of noxious, and sometimes toxic bloom-forming cyanobacteria (Fogg, 1969; Huisman et al, 2005; Paerl & Fulton, 2006)
We quantified archaeal and bacterial 16S rRNA gene sequences, and cyanobacterial 16S rRNA gene sequences, and eukaryotic 18S rRNA gene sequences to qualitatively estimate the contribution of these organisms to water column and sediment biomass
We present community composition and abundance data of planktonic and sediment microbes across a range of eutrophic lakes and reservoirs on select aquatic ecosystems with known mussel presence or absence that have been impacted by cyanobacterial blooms in Ohio, Indiana, and Kentucky, including portions of Lake Erie
Summary
A leading cause of eutrophication in freshwater ecosystems, leads to the proliferation of noxious, and sometimes toxic bloom-forming cyanobacteria (Fogg, 1969; Huisman et al, 2005; Paerl & Fulton, 2006). Climate change, including warming temperatures and increased hydrologic variability, is expected to increase the growth and dominance of cyanoHABs (Paerl, 2017). It is not clear how the spread of non-native mussels will impact eutrophication, Hydrobiologia (2020) 847:939–965
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
