Abstract
Increasing salinity in freshwater environments is a growing problem due both to the negative influences of salts on ecosystems and their accumulation and persistence in environments. Two major sources of increased salinity from sodium chloride salts (NaCl) are saline wastewaters co-produced during energy production (herein, wastewaters) and road salts. Effects of road salts have received more attention, but legacy contamination from wastewaters is widespread in some regions and spills still occur. Amphibians are sensitive to contaminants, including NaCl, because of their porous skin and osmoregulatory adaptations to freshwater. However, similarities and differences between effects of wastewaters and road salts have not been investigated. Therefore, we investigated the relative influence of wastewaters and NaCl at equivalent concentrations of chloride on three larval amphibian species that occur in areas with increased salinity. We determined acute toxicity and growth effects on Boreal Chorus Frogs (Pseudacris maculata), Northern Leopard Frogs (Rana pipiens), and Barred Tiger Salamanders (Ambystoma mavortium). We posited that wastewaters would have additive effects on amphibians compared to NaCl because wastewaters often have additional toxic heavy metals and other contaminants. For NaCl, toxicity was higher for frogs than the salamander. Toxicity of wastewaters was also similar between chorus and leopard frogs. Only chorus frog survival was lower when exposed to wastewater compared to NaCl. Mass and length of leopard and chorus frog larvae decreased with increasing salinity after only 96 hours of exposure but did not for tiger salamanders. Size of leopard frogs was lower when exposed to NaCl compared to wastewater. However, growth effects were similar between wastewater and NaCl for chorus frogs. Taken together, our results suggest that previous studies on effects of road salt could inform future studies and management of wastewater-contaminated ecosystems, and vice versa. Nevertheless, effects of road salts and wastewaters may be context-, species-, and trait-specific and require further investigations. The negative influence of salts on imperiled amphibians underscores the need to restore landscapes with increased salinity and reduce future salinization of freshwater ecosystems.
| Original language | English |
|---|---|
| Article number | 105626 |
| Journal | Aquatic Toxicology |
| Volume | 228 |
| DOIs | |
| State | Published - Nov 2020 |
Funding
This project was conducted under University of Montana Institutional Animal Care and Use Committee permit #024-18BHWB-050818. Egg masses and larvae were collected under U.S. Fish and Wildlife special use permit #61530-18-003 and #62560-18-023, Montana Fish, Wildlife & Parks scientific collection permit #2018-083-W and #2019-100-W, and North Dakota Game and Fish collection licenses #GNF04616269 and #GNF04882458. We thank the U.S. Geological Survey , University of Montana , and the Nelson Schwab Family Foundation for funding to complete this study. For assistance in the field and laboratory, many thanks are owed to K. Stemp, S. Williams, C. Manning, K. Honeycutt, and G. Renteria. We thank the Breuner Lab and E. Kenison for feedback on analyses and interpretation. We are grateful to K. Smalling, E. Crespi, J. Millspaugh, and L. Eby for reviewing earlier drafts of this manuscript. We thank R. Martin of Enābl, LLC for providing illustrations of our study species for figures. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Data are available at https://doi.pangaea.de/10.1594/PANGAEA.913836 and https://doi.pangaea.de/10.1594/PANGAEA.913841 ( Tornabene and Breuner, 2020a , 2020b ). This project was conducted under University of Montana Institutional Animal Care and Use Committee permit #024-18BHWB-050818. Egg masses and larvae were collected under U.S. Fish and Wildlife special use permit #61530-18-003 and #62560-18-023, Montana Fish, Wildlife & Parks scientific collection permit #2018-083-W and #2019-100-W, and North Dakota Game and Fish collection licenses #GNF04616269 and #GNF04882458. We thank the U.S. Geological Survey, University of Montana, and the Nelson Schwab Family Foundation for funding to complete this study. For assistance in the field and laboratory, many thanks are owed to K. Stemp, S. Williams, C. Manning, K. Honeycutt, and G. Renteria. We thank the Breuner Lab and E. Kenison for feedback on analyses and interpretation. We are grateful to K. Smalling, E. Crespi, J. Millspaugh, and L. Eby for reviewing earlier drafts of this manuscript. We thank R. Martin of En?bl, LLC for providing illustrations of our study species for figures. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Data are available at https://doi.pangaea.de/10.1594/PANGAEA.913836 and https://doi.pangaea.de/10.1594/PANGAEA.913841 (Tornabene and Breuner, 2020a, 2020b).
| Funders | Funder number |
|---|---|
| North Dakota Game and Fish Department | 04882458, 04616269 |
| 2020a | |
Keywords
- Energy production
- Growth
- LC50
- Salt
- Survival
