Experimental Iron Amendment Suppresses Toxic Cyanobacteria in a Hypereutrophic Lake
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Authors
Orihel, Diane
Schindler, David
Ballard, Nathaniel
Wilson, Lindsey
Vinebrooke, Rolf
Date
2016-02-25
Type
journal article
Language
en
Keyword
Cyanobacteria , Eutrophication , Freshwater , Harmful algal blooms (HABs) , Internal 36 phosphorus loading , Iron treatment , Lake remediation , Microcystin , Sediments
Alternative Title
Abstract
The effects of reducing nutrient inputs to lakes and reservoirs are often delayed by hysteresis resulting from internal phosphorus (P) loading from sediments. Consequently, controlling harmful algal blooms (HABs) in many eutrophic ecosystems requires additional management to improve water quality. We manipulated iron (Fe) concentrations in a hypereutrophic lake to determine if Fe amendment would suppress HABs by inhibiting P release from sediments. Our experiment consisted of 15 in situ mesocosms, 12 of which each received a different dose of Fe (ranging from 2 to 225 g/m2); the remaining three were unmanipulated to serve as controls. Iron amendment decreased P accumulation in porewaters and the flux of P from sediments, which significantly lowered P concentrations in the water column. Iron exerted significant dose-dependent negative effects on the biomass of phytoplankton and periphyton, and reduced the dominance of cyanobacteria. Even at the lowest doses, Fe appeared to reduce the toxicity of cyanobacterial blooms, as measured by concentrations of hepatotoxic microcystins. Overall, our findings highlight the potential for Fe treatment as an effective strategy for minimizing HABs in eutrophic lakes and reservoirs. More broadly, our study reinforces the importance of Fe in regulating the trophic state of freshwaters, and the sensitivity of certain ecosystems to changes in Fe supply. Finally, we hypothesize that decreases in natural Fe supplies to lakes associated with anthropogenic activities may worsen outbreaks of toxic cyanobacteria.
Description
This is the peer reviewed version of the following article: Orihel, D.M., Schindler, D.W., Ballard, N.C., Wilson, L.R. and Vinebrooke, R.D. (2016), Experimental iron amendment suppresses toxic cyanobacteria in a hypereutrophic lake. Ecol Appl, 26: 1517-1534, which has been published in final form at https://doi.org/10.1890/15-1928. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.
Citation
Orihel, D.M., Schindler, D.W., Ballard, N.C., Wilson, L.R. and Vinebrooke, R.D. (2016), Experimental iron amendment suppresses toxic cyanobacteria in a hypereutrophic lake. Ecol Appl, 26: 1517-1534. https://doi.org/10.1890/15-1928
Publisher
Wiley