Increasing accuracy of lake nutrient predictions in thousands of lakes by leveraging water clarity data

Aquatic scientists require robust, accurate information about nutrient concentrations and indicators of algal biomass in unsampled lakes in order to understand and predict the effects of global climate and land-use change. Historically, lake and landscape characteristics have been used as predictor variables in regression models to generate nutrient predictions, but often with significant uncertainty. An alternative approach to improve predictions is to leverage the observed relationship between water clarity and nutrients, which is *Correspondence: txw19@psu.edu Author Contribution Statement: All authors contributed to the development of the paper. T.W. and N.R.L. led the writing of the manuscript. E.M.S., E.M.H., N.B.W., and M.L.B. performed the statistical analysis. K.B.S.K., I.M., and J.S. performed database queries and summaries. All coauthors edited and contributed to writing. After the coleads, authors are listed in alphabetical order by groups according to level of contribution. Data Availability Statement: All data are available from the LAGOSNE R package (https://cran.r-project.org/web/packages/LAGOSNE). The code and data required to perform the analysis described in this article are located at https://doi.org/10.5281/zenodo.3484680. Associate editor: Mark Scheuerell Additional Supporting Information may be found in the online version of this article. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

[1]  D. Canfield,et al.  Prediction of Chlorophyll a Concentrations in Florida Lakes: Importance of Aquatic Macrophytes , 1984 .

[2]  Aline Jaimes,et al.  The importance of lake-specific characteristics for water quality across the continental United States. , 2015, Ecological applications : a publication of the Ecological Society of America.

[3]  D. Schindler,et al.  Eutrophication science: where do we go from here? , 2009, Trends in ecology & evolution.

[4]  Owen L. Petchey,et al.  Predictive systems ecology , 2013, Proceedings of the Royal Society B: Biological Sciences.

[5]  C. D. Brown,et al.  Volunteer Lake Monitoring: Testing the Reliability of Data Collected by the Florida LAKEWATCH Program , 2002 .

[6]  Monica G. Turner,et al.  Cross–Scale Interactions and Changing Pattern–Process Relationships: Consequences for System Dynamics , 2007, Ecosystems.

[7]  F. Rigler,et al.  Chlorophyll–Phosphorus Relationships for Subarctic Lakes in Western Canada , 1987 .

[8]  Tyler Wagner,et al.  Spatial Variation in Nutrient and Water Color Effects on Lake Chlorophyll at Macroscales , 2016, PloS one.

[9]  J. Downing,et al.  Predicting cyanobacteria dominance in lakes , 2001 .

[10]  William W. Walker,et al.  Use of hypolimnetic oxygen depletion rate as a trophic state index for lakes , 1979 .

[11]  Marvin E. Bauer,et al.  Geospatial and Temporal Analysis of a 20‐Year Record of Landsat‐Based Water Clarity in Minnesota's 10,000 Lakes , 2014 .

[12]  H. Paerl,et al.  Climate change: links to global expansion of harmful cyanobacteria. , 2012, Water research.

[13]  R. Carlson A trophic state index for lakes1 , 1977 .

[14]  D. Schindler The dilemma of controlling cultural eutrophication of lakes , 2012, Proceedings of the Royal Society B: Biological Sciences.

[15]  W. Dodds,et al.  Eutrophication of U.S. freshwaters: analysis of potential economic damages. , 2009, Environmental science & technology.

[16]  Monica G Turner,et al.  Annual precipitation regulates spatial and temporal drivers of lake water clarity. , 2017, Ecological applications : a publication of the Ecological Society of America.

[17]  Tyler Wagner,et al.  Lake nutrient stoichiometry is less predictable than nutrient concentrations at regional and sub-continental scales. , 2017, Ecological applications : a publication of the Ecological Society of America.

[18]  Kendra Spence Cheruvelil,et al.  Landscape drivers of regional variation in the relationship between total phosphorus and chlorophyll in lakes , 2011 .

[19]  M. Graham CONFRONTING MULTICOLLINEARITY IN ECOLOGICAL MULTIPLE REGRESSION , 2003 .

[20]  Gong Lin,et al.  A semi-analytical scheme to estimate Secchi-disk depth from Landsat-8 measurements , 2016 .

[21]  Tyler Wagner,et al.  Combining nutrient, productivity, and landscape‐based regressions improves predictions of lake nutrients and provides insight into nutrient coupling at macroscales , 2018, Limnology and Oceanography.

[22]  Kevin C Elliott,et al.  Quantifying the contribution of citizen science to broad‐scale ecological databases , 2019, Frontiers in Ecology and the Environment.

[23]  J. Elliott,et al.  Is the future blue-green? A review of the current model predictions of how climate change could affect pelagic freshwater cyanobacteria. , 2012, Water research.

[24]  W. W. Jones,et al.  LAGOS-NE: a multi-scaled geospatial and temporal database of lake ecological context and water quality for thousands of US lakes , 2017, GigaScience.

[25]  Debra P. C. Peters,et al.  Strategies for ecological extrapolation , 2004 .