App-based tool quantifies pesticide toxicity in watersheds; identifies mitigation opportunities (IMAGE) PLOS Caption Watershed applied toxicity. The heat map and legend values represent applied toxicity as the Net Toxicity Index (NTI), the total applied toxicity of pesticide applications to all aquatic taxa investigated over the simulation period, fish, invertebrates, nonvascular aquatic plants, and vascular aquatic plants. Results are displayed for each study extent, a) California’s HUC8 watersheds and b) the HUC12 subwatersheds in the Bay-Delta Watershed. The NTI ranges identify the magnitude of toxicity released during pesticide applications, with values in the upper range, greater than 50,000,000, illustrating areas of applied toxicity that are up to 8 orders of magnitude greater than other watersheds. Base map source:http://goto.arcgisonline.com/maps/Reference/World_Imagery. Credit Parker et al., 2023, PLOS Water, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/) Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.