Mexican spadefoot toads (Spea multiplicata) are native amphibians in the Grand Canyon watershed that use temporary surface water habitats for breeding. After an aquatic larval period, tadpoles metamorphose and spend the rest of their lives on land. Both adults and tadpoles of S. multiplicata have been detected in the Plain Mine (formerly Canyon Mine) pond, and tadpoles collected from the mine pond had higher whole-body concentrations of several metals than tadpoles collected from a nearby earthen stock tank1. Metals in mine pond sediments and water may pose a risk of direct toxicity to native amphibians such as S. multiplicata, and metamorphosing S. multiplicata may also transfer metals from the mine pond to terrestrial wildlife. Amphibian studies are underway to better understand the potential toxicity of mine pond water to S. multiplicata and to determine the rate at which metals accumulate in S. multiplicata tadpoles. These studies will help estimate the risk, if any, of metals in the Plain Mine (formerly Canyon Mine) pond to the health of toads and wildlife species that consume toads.
Ongoing
Task 5a: Compile/evaluate existing and newly collected monitoring data from various agencies/sources Task 7b: Collect/analyze water and sediment samples Task 7c: Collect/analyze samples from biota with focus on trust resources
1 Hinck, J.E., Cleveland, D., Brumbaugh, W.G., Linder, G., and Lankton, J., 2017, Pre-mining trace element and radiation exposure to biota from a breccia pipe uranium mine in the Grand Canyon (Arizona, USA) watershed: Environmental Monitoring and Assessment, February 2017
Bethany Kunz
Research Biologist
Columbia Environmental Research Center
573.441.2998
bkunz@usgs.gov
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U.S. Forest Service (USFS) |
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University of North Carolina |
