In the original article, there was a spreadsheet error in the calculation of hydrogen peroxide (H2O2) concentrations in Lake Erie. Hydrogen peroxide concentrations were measured using the Amplex Red method, which requires subtraction of the background reagent signal from all samples and standards. Subtraction of background reagent signal was not done when reporting hydrogen peroxide concentrations in the original manuscript; this error has now been corrected. Corrected hydrogen peroxide concentrations are lower than reported in the paper by a factor of 1.8 (i.e., original H2O2 / 1.8 = corrected H2O2). Corrected H2O2 concentrations are significantly, linearly correlated with the originally reported H2O2 concentration (p < 0.001, R2 = 0.8, slope = 1.8 ± 0.04). Thus, the temporal and spatial patterns in H2O2 concentrations reported in Lake Erie in Figures 7D, 10D, 11 remain the same, but the hydrogen peroxide concentrations reported in Figures 3, 4D, 8C, 10D, 11, 13 are lower by a factor of 1.8. Corrected H2O2 concentrations were within measurement error of the original reported concentration for 12% of the Lake Erie samples, while 88% of the corrected H2O2 concentrations were significantly lower than the original, reported concentration.
Corrected text is reported here. In the abstract and results section, the text below replaces the original text from the published manuscript with the only difference being the corrected H2O2 concentrations. In the discussion and conclusions sections, minor revisions were made to sentences in the published manuscript (shown below) to provide a more conservative interpretation of the relative importance of biological activity to H2O2 concentrations. That is, given the lower H2O2 concentrations after correction, photochemical processes of CDOM may account for a larger fraction of H2O2 than originally assessed. However, the main conclusion of the paper remains the same: that biological activity likely contributed substantially to H2O2 concentrations in Lake Erie.
Abstract:
“Concentrations of H2O2 in Lake Erie ranged from 2 ± 24 nM to 1140 ± 240 nM (average of 162 ± 11 nM; n = 221).
Materials and Methods, Section 2.6 H2O2Concentrations, Paragraph Number 1:
Results, Section 3.4 H2O2Concentrations in Lake Erie, Paragraph Number 1:
Hydrogen peroxide concentrations in the surface waters of Lake Erie varied by over an order of magnitude during the study period, from 2 ± 24 to 1,140 ± 240 nM (average ± SE from triplicate measurements of each water sample), with an overall average of 162 ± 11 nM (average ± SE, n = 221; Figure 10D).
Results, Section 3.4 H2O2Concentrations in Lake Erie, Paragraph Number 3:
The largest difference in H2O2 concentration between surface water and depth was observed when H2O2 at 21 m was nearly double the surface concentration at the same site under mixed conditions (312 ± 53 nM vs. 148 ± 42 nM H2O2 in bottom vs. surface, respectively at site 949 in the central basin; Figure 8C).
Discussion, Section 4, Paragraph Number 1:
The average and range of hydrogen peroxide (H2O2) concentrations in Lake Erie (162 ± 11 nM, up to a maximum of 1,140 ± 240 nM; Table 1 and Figure 10D) were higher than the range previously observed at one station in the western basin of Lake Erie in August 1987 (100–200 nM; Cooper et al., 1989), but within the wide range of H2O2 concentrations observed in lakes (~10 nM to >2 μM; (Cooper and Zika, 1983; Cooper et al., 1989; Häkkinen et al., 2004; Febria et al., 2006; Khan et al., 2013; Scully et al., 1996).
Discussion, Section 4, Paragraph Number 2:
Using the average calculated photochemical production rate of 67 ± 3 nM h−1 H2O2 by CDOM, it would take almost 3 h of mid-day light to produce the observed average concentration of H2O2 (162 ± 11 nM) assuming no other sources and no sinks. All water samples were collected between 09:00 to 15:30 h, with the majority of samples collected between 10:00 h and 12:30 h, suggesting that there could have been sufficient time and UV light for photochemical production to generate the observed concentrations if H2O2 sinks were minimal.
Discussion, Section 4, Paragraph Number 3:
Photochemical production of H2O2 by CDOM could account for the observed H2O2 if CDOM in the lake consistently had ~ 3-fold higher apparent quantum yields (Φλ; Equation 3) than we used.
Discussion, Section 4, Paragraph Number 7:
For example, given that the depths of bottom water sampled (4–61 m) were also greater than the depth of UV light penetration (depth of 1% light was 1.5 ± 0.1 m for 412 nm), there was not enough UV light to produce the 30–300 nM H2O2 observed at depth (Figure 8C).
However, in this study, similar magnitudes of H2O2 concentrations were observed between surface and bottom waters even at depths >20 m during stratified conditions (Figure 8C).
Conclusions and Implications, Section 5, Paragraph Number 1:
This study demonstrated that CDOM and H2O2 concentrations were not related and that even the upper estimates of photochemical production of H2O2 by CDOM were likely too low to account for all H2O2 (especially at depths below the photic zone). These results, combined with measured and estimated rates of biological production of H2O2 that can equal or exceed photochemical production (this study; Marsico et al., 2015), strongly suggest that biological activity contributes substantially to H2O2 concentrations in Lake Erie.
Statements
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Summary
Keywords
hydrogen peroxide, Lake Erie, cyanobacteria, Microcystis aeruginosa, microcystins, harmful algal blooms, Great Lakes, CDOM
Citation
Cory RM, Davis TW, Dick GJ, Johengen T, Denef VJ, Berry M, Page SE, Watson SB, Yuhas K and Kling GW (2017) Corrigendum: Seasonal Dynamics in Dissolved Organic Matter, Hydrogen Peroxide, and Cyanobacterial Blooms in Lake Erie. Front. Mar. Sci. 4:377. doi: 10.3389/fmars.2017.00377
Received
09 October 2017
Accepted
09 November 2017
Published
21 November 2017
Volume
4 - 2017
Edited and reviewed by
Leanne C. Powers, Chesapeake Biological Laboratory, United States
Updates
Copyright
© 2017 Cory, Davis, Dick, Johengen, Denef, Berry, Page, Watson, Yuhas and Kling.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Rose M. Cory rmcory@umich.edu
†Present Address: Sarah E. Page, Arcadis U.S., Inc., Minneapolis, MN, United States
This article was submitted to Marine Biogeochemistry, a section of the journal Frontiers in Marine Science
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