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Step-by-Step Calculation and Spreadsheet Tools for Predicting Stressor Levels that Extirpate Genera and Species
Citation:
Cormier, S., L. Zheng, E. Leppo, AND A. Hamilton. Step-by-Step Calculation and Spreadsheet Tools for Predicting Stressor Levels that Extirpate Genera and Species. Integrated Environmental Assessment and Management. Allen Press, Inc., Lawrence, KS, 14(2):174-180, (2018). https://doi.org/10.1002/ieam.1993
Impact/Purpose:
Elevated water ionic concentration as measured by SC can adversely affect aquatic life in freshwaters. Protection and reestablishment of conditions that support aquatic life depend upon chemical and physical benchmarks, standards, and criteria to set loading limits and clean up goals. States may choose to use BEAT-XC95 and BEAT-HC05 to develop water quality criteria for SC. The biological extirpation analysis tools (BEAT) differ in that they use the same equations used to develop field-based benchmarks (EPA 2011) and criteria (EPA 2016). Those calculations involve several arithmetic manipulations which are tedious to perform by hand. Because large data sets and a variety of analyses are key to the development of the field-based method, the original work to develop the method used the open source statistical software R (R Core Team 2014). However, some researchers may not be familiar with R and not every application requires the flexibility of R. In fact, the calculations can be done with a hand-held calculator. However, a spreadsheet tool makes it easier. To enable a wide array of users and applications, we developed BEAT-XC95 and BEAT-HC05. BEAT-XC95 enables users to calculate the exposure that is predicted to extirpate a species or genera from a location or area. It generates an XC95 value, a plot of a taxon’s proportional occurrence with respect to a stressor, and a plot of a taxon’s probability of being observed within discrete stressor ranges or bins. BEAT-HC05 generates a cumulative frequency distribution of XC95 values (XCD) and calculates the stressor level predicted to extirpate 5% of taxa. BEAT-HC05 enables analysis of a set of species or genera along a stressor gradient. By changing the inclusion criteria for data sets, one can estimate benchmarks (USEPA 2011, 2016), assess local causes (Coffey et al, 2014, Cormier et al. 2012) and risks, and evaluate potential confounders (Suter and Cormier 2013, USEPA 2016).
Description:
In 2011, the U.S. Environmental Protection Agency (USEPA) released a field-based method for estimating the extirpation of freshwater aquatic benthic invertebrates by ionic mixtures dominated by HCO3−, SO42−, and Ca2+ measured as specific conductivity (SC). The estimate of extirpation was SC at the 95th centile (XC95) of a weighted cumulative frequency distribution (CFD) of a genus over a range of SC. A CFD of XC95 values was used to predict the SC at which 5% of genera were likely to be extirpated. Because there are many uses for XC95 values and many data sets that could be analyzed using this method, we laid out a step-by-step method for calculating XC95 values and the stressor level that predicts a 5% extirpation of genera (HC05). Although the calculations can be done with a hand-held calculator, we provide 2 downloadable Microsoft Excel® spread sheet calculation tools that are easy to use to calculate XC95 values, to plot a taxon’s XC95 cumulative frequency distribution with increasing SC, and to plot probabilities of observing a taxon at a particular SC. They also plot cumulative frequency distributions of XC95 values and calculate HC05. In addition to the tools, we provide an example and the output of XC95 values for 176 distinct aquatic benthic invertebrates in Central Appalachia.
URLs/Downloads:
DOI: Step-by-Step Calculation and Spreadsheet Tools for Predicting Stressor Levels that Extirpate Genera and Species
STEP-BY-STEP NIHMS-1579289.PDF (PDF, NA pp, 931.357 KB, about PDF)
NIHMS1579289-SUPPLEMENT-APPENDIX_7_FORMAT_CORRECTED.PDF (PDF, NA pp, 594.125 KB, about PDF)
NIHMS1579289-SUPPLEMENT-APPENDIX_8_FORMAT_CORRECTED.PDF (PDF, NA pp, 437.005 KB, about PDF)
NIHMS1579289-SUPPLEMENT-APPENDIX_9_FORMAT_CORRECTED.PDF (PDF, NA pp, 11015.771 KB, about PDF)
NIHMS1579289-SUPPLEMENT-APPENDIX_S1_FORMAT_CORRECTED.PDF (PDF, NA pp, 321.532 KB, about PDF)
NIHMS1579289-SUPPLEMENT-APPENDIX_S4_FORMAT_CORRECTED.PDF (PDF, NA pp, 71.457 KB, about PDF)
NIHMS1579289-SUPPLEMENT-APPENDIX_S6_FORMAT_CORRECTED.PDF (PDF, NA pp, 155.846 KB, about PDF)
EXCEL TOOLS.ZIP
https://www.ncbi.nim.nih.gov/pmc/articles/PMC7241421/