Reducing aquatic phosphorus eutrophication can increase toxins production

Cyanobacteria pose a serious threat to water quality, aquatic wildlife and fisheries. The reduction of phosphorus in freshwaters is a widely used measure to control algal blooms caused by these bacteria. Although phosphorus reduction reduces the total biomass, it can lead to increased toxin production by cyanobacteria.

Nº 18

Lake Erie

some attempts made
past case
Region-1
Region-2
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Region-4
ongoing case
no attempts made

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Reducing aquatic phosphorus eutrophication can increase toxins production

Cyanobacteria pose a serious threat to water quality, aquatic wildlife and fisheries. The reduction of phosphorus in freshwaters is a widely used measure to control algal blooms caused by these bacteria. Although phosphorus reduction reduces the total biomass, it can lead to increased toxin production by cyanobacteria.

Model predictions indicate that reductions in phosphorus in Lake Erie will lead to increased toxicity in the lake. These reductions are the result of an intervention to reduce the negative impact of nutrient-laden runoff from agricultural activities. In a situation with lower levels of phosphorus, cyanobacteria may produce more toxins. The debate on this issue is not yet settled, as another study has questioned the validity of the results, while the authors of the original study have defended their methodology.

Hellweger, F. L., Martin, R. M., Eigemann, F., Smith, D. J., Dick, G. J., & Wilhelm, S. W. (2022). Models predict planned phosphorus load reduction will make Lake Erie more toxic. Science, 376(6596), 1001-1005. https://doi-org.proxy.library.uu.nl/10.1126/science.abm6791

Huisman, J., Dittmann, E., Fastner, J., Schuurmans, J. M., Scott, J. T., de Waal, D. B. van, Visser, P. M., Welker, M., & Chorus, I. (2022). Comment on “Models predict planned phosphorus load reduction will make Lake Erie more toxic”. Science, 378(6620), eadd9959. https://doi.org/10.1126/science.add9959

Hellweger, F. L., Schampera, C., Martin, R. M., Eigemann, F., Smith, D. J., Dick, G. J., & Wilhelm, S. W. (2022). Response to Comment on “Models predict planned phosphorus load reduction will make Lake Erie more toxic”. Science, 378(6620), eade2277. https://doi.org/10.1126/science.ade2277

Hellweger, F. L., Martin, R. M., Eigemann, F., Smith, D. J., Dick, G. J., & Wilhelm, S. W. (2022). Models predict planned phosphorus load reduction will make Lake Erie more toxic. Science, 376(6596), 1001-1005. https://doi-org.proxy.library.uu.nl/10.1126/science.abm6791

Paerl, H. W., Otten, T. G., & Kudela, R. (2018). Mitigating the expansion of harmful algal blooms across the freshwater-to-marine continuum. Environ. Sci. Technol., 52(10), 5519–5529. https://doi.org/10.1021/acs.est.7b05950