Robin A. Femmer | Search USGS

USGS2025

Cyanotoxin and domoic acid occurrence, relation with salinity, and potential recreational health risks in U.S. coasts in the 2015 US EPA National Coastal Condition Assessment

In the first nationwide study of cyanotoxins in U.S. estuaries, algal toxins, cyanotoxins, chlorophyll, and salinity were measured in samples collected during the National Coastal Condition Assessment 2015. Anatoxin-a (ANAA), cylindrospermopsin (CYLS), domoic acid (DMAC), and microcystins (MCs) were detected by LC/MS/MS in 0.6, 0.9, 8.3, and 2.0 % of samples with mean concentrations of detections of 0.13, 0.13, 0.53, and 0.49 µg/L, respectively. MCs by ELISA were also evaluated, and 4.0 % of samples had measurable MCs with a mean of 0.78 µg/L. While ANAA and CYLS were detected south of 40° latitude, MCs by ELISA and DMAC occurred nationwide. Results were compared to freshwater recreational health thresholds from the World Health Organization and US Environmental Protection Agency to evaluate potential recreational exposure to MCs and CYLS since marine thresholds do not currently exist. Cyanotoxins were categorized using the 2021 World Health Organization Alert Level Framework for recreational exposure with 99.4, 99.1, 94.7, 98.0, and 44.7 % of samples being at the Vigilance Level for ANAA, CYLS, MCs (ELISA and LC/MS/MS), and chlorophyll, respectively with the remaining samples at Alert Level 1. Chlorophyll had 19.9 and 9.9 % of samples at Alert Level 1 and Alert Level 2, respectively. All cyanotoxins were below US EPA health advisory thresholds. ANAA, CYLS, DMAC, and MCs by ELISA were detected in samples with a wide range of salinities, while MCs by LC/MS/MS only occurred in samples with salinity <5 part per thousand (PPT). The source of cyanotoxins is likely a combination of inland transport and in situ estuarine production.

contiguous United States↗

USGS2022

Corrigendum: Associations between cyanobacteria and indices of secondary production in the western basin of Lake Erie

In the last year, we became aware that data used in our above-referenced manuscript from 2018 published in Limnology and Oceanography contained significant errors. In the 2018 manuscript, we found that indices of secondary production were negatively correlated to indices of cyanobacterial abundance and toxicity. Unfortunately, one of our indices of cyanobacterial abundance (biovolume) and our measurement of toxicity (microcystin concentration) were inaccurate in the data we used in the 2018 manuscript. Upon discovering these errors, we immediately began correcting the repositories where these data were available. Having corrected those data repositories, we are now reporting on the re-analysis of the data using the methods previously described in the 2018 manuscript. Although the relationships are slightly different, our interpretation is that the conclusions of the 2018 manuscript are still valid using the corrected data. The data errors we experienced were traced to a spreadsheet that was used to share data among the research team, which had errors caused by mistakes in copy-pasting formulas instead of data and ‘inadvertent’ edits that were saved by the spreadsheet's auto-save function. We apologize to the scientific community for these errors.

Lake Erie↗