National and regional calculations for hazard-exposure by 383 fish taxa to surface water supply and use imbalance during spawning months across the conterminous United States for water years 2000-2020

This data release contains the output from hazard-exposure analysis of 383 fish species across the Conterminous US (CONUS) to surface water supply and use imbalances (SUI) during their spawning months, hereafter referred to as spawning exposure.

SUI were calculated by Martinez and others (2026) by combining the monthly water balance from water supply and human consumptive uses for CONUS from water years 2000-2020 at the HUC12 scale. Water supply was calculated from two physically-based hydrologic models, and consumptive water use was calculated from three separate national models for agricultural irrigation, thermoelectric power generation, and public supply. Water budgets were routed through the surface water flow network (to allow for upstream consumptive uses to affect downstream water availability) and used to determine potential water limitations for human populations and fish species. We overlaid water imbalances with the modeled ranges of 415 fish species, including Species of Greatest Conservation Need, recreationally important, and common native taxa. SUI was evaluated within each HUC12 specifically within the spawning months for each taxa. Our analyses indicated multiple species with notably proportions of their habitats exposed to high or severe spawning exposure, especially the federally-listed Arkansas River shiner. This analysis can be used to identify fish taxa particularly exposed to water availability issues, specifically the hazard of water scarcity due to surface water supply and use imbalances, during the physiologically important spawning period. However, as this analysis did not consider specific taxa-level differences as to the sensitivity of different species to limited water supply, this should be considered a hazard-exposure analysis and not a risk assessment for these species.

This data release contains five tabular datasets in comma delineated standards (.csv), covering a tabular data dictionary, supporting analysis input, raw analysis output, and summarized versions at two spatial scales for convenience. They are:

data_dictionary.csv - A data dictionary containing entity and attribute information about variable names, descriptions, types, ranges, and unique values for easy access.
SpawningExposure_TaxaSpawningWeights.csv - Dataset used to weigh spawning months for each taxon in calculation of the spawning exposure. Derived from Frimpong and Angermeier, 2011.
SpawningExposure_SUI_HUC12.csv - CONUS level dataset of average spawning exposure to SUI from water years 2000-2020 for each fish taxa reported for each HUC12 where they are present.
SpawningExposure_SUI_CONUS_Summary.csv - A spatial summary of spawning exposure to SUI by fish taxa reporting the range-average exposure and percentage of habitat range in each SUI category class.
SpawningExposure_SUI_Regional_Summary.csv - A spatial summary of spawning exposure to SUI by fish taxa reporting, within each hydrologic region, the region range-average exposure and percentage of the region's habitat range in each SUI category class.