| Autor: |
Barnard,Malcolm A., Plaas,Haley E., Paerl,Ryan W., Karl,Colleen M., Holland,W. Christopher, Hardison,D. Ransom, Hall,Nathan S., Bartenfelder,Amy N., Rossignol,Karen L., Braddy,Jeremy S., Sloup,Randolph S., Paerl,Hans W. |
| Rok vydání: |
2022 |
| Předmět: |
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| DOI: |
10.5281/zenodo.7015162 |
| Popis: |
The Chowan River (CR)-Albemarle Sound Estuary, NC has been plagued by a resurgence of toxigenic cyanobacterial harmful algal blooms (CyanoHABs) since 2015. Both N2-fixing and Non-N2-fixing cyanobacteria blooms have occurred in the CR blooms and, in summer 2020, potentially harmful N2-fixing Dolichospermum spp. was dominant. To identify the nutritional drivers of the summer 2020 CyanoHAB, we conducted nitrogen (N), phosphorus (P), and B vitamin addition experiments and measured N2-fixation rates using acetylene reduction assays. Cyanobacteria are generally thought to not require external B vitamins, though the opportunistic use of external vitamins may increase metabolism directly or through stimulation of members of the cyanobacterial ‘microbiome’. The CR phytoplankton community exhibited N-limitation with a secondary vitamin limitation in NH4 addition treatments. B vitamin additions influenced the community composition of the CR CyanoHABs by increasing chlorophyte biomass and reducing cyanobacterial biomass. Furthermore, given the high N2-fixation rates (240 nmol N L-1 h-1), further research is required to evaluate the budgetary importance of N2-fixation relative to external N inputs and determine the effectiveness of reducing external N loads in reducing the severity of the blooms. The results demonstrate the importance of N in sup-porting CR CyanoHABs and the need to better understand multiple nutritional drivers of the recurring blooms. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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