EARLY HEARING DETECTION AND INTERVENTION VIRTUAL CONFERENCE
MARCH 2-5, 2021
(Virtually the same conference, without elevators, airplane tickets, or hotel room keys)
5/26/2021 | 8:30 AM - 10:30 AM | Progression of N fixation during a riverine algal bloom | Virtual Platform
Progression of N fixation during a riverine algal bloom
The Upper Clark Fork River (UCFR) suffers from anthropogenic (N) enrichment that, coupled with naturally high Phosphorous (P) availability and sunlight, lead to annual nuisance filamentous algae (Cladophora) blooms often leading to a secondary N-fixing cyanobacterial bloom reflecting N-limitation. Under such conditions, N-fixation can play a significant role in stimulating primary productivity. We used the acetylene reduction technique to quantify N-fixation along the progression of blooms in a 5th-order section of the UCFR. A suite of associated environmental variables was measured in order to determine the environmental controls to N fixation and the consequences of enhanced N-fixation to the system. Over the course of the algal bloom, standing crops of phycocyanin increased linearly to a maximum of 65 mg/m2). Following dominance by Cladophora, N-fixation rates increased from 0.15 to 3.3 mg/m2*h-1, then slowly decreased towards the end of the growing season. The N/P ratios of the water column shifted from 0.3 to 9.3, mostly due to the increase in availability of ammonium. Light and temperature explained 70% of the variation in phycocyanin corrected N fixation. Enhanced algal growth due to N-Fixation was associated with declines in ambient P concentrations.
- Biogeochemistry
- Ecosystem functioning
- Nutrients
Presentation:
This presentation has not yet been uploaded.
Handouts:
Handout is not Available
Transcripts:
CART transcripts are NOT YET available, but will be posted shortly after the conference
Presenters/Authors
Rafael Feijó de Lima
(), University of Montana, rafael.feijo@mso.umt.edu;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Thomas Horner
(), University of Montana, thomas.horner@umconnect.umt.edu;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
Marc Peipoch
(), Stroud Water Research Center, mpeipoch@stroudcenter.org;
ASHA DISCLOSURE:
Financial -
Nonfinancial -
H. Maurice Valett
(), University of Montana, Division of Biological Sciences, maury.valett@umontana.edu;
ASHA DISCLOSURE:
Financial -
Nonfinancial -