Metal accumulation varies with life history, size, and development of larval amphibians

Authors: K L Smalling; Emily B Oja; Danielle M Cleveland; J M Davenport; Collin A Eagles-Smith; Evan HC Grant; Patrick M Kleeman; Brian J Halstead; Kenzi M Stemp; B J Tornabene; Z J Bunnell; Blake R Hossack
Contribution Number: 787

https://doi.org/10.1016/j.envpol.2021.117638

Abstract/Summary

Amphibian larvae are commonly used as indicators of aquatic ecosystem health because they are susceptible to contaminants. However, there is limited information on how species characteristics and trophic position influence contaminant loads in larval amphibians. Importantly, there remains a need to understand whether grazers (anurans) and predators (salamanders) provide comparable information on contaminant accumulation or if they are each indicative of unique environmental processes and risks. To better understand the role of trophic position in contaminant accumulation, we analyzed composite tissues for 10 metals from larvae of multiple co-occurring anuran and salamander species from 20 wetlands across the United States. We examined how metal concentrations varied with body size (anurans and salamanders) and developmental stage (anurans) and how the digestive tract (gut) influenced observed metal concentrations. Across all wetlands, metal concentrations were greater in anurans than salamanders for all metals tested except mercury, selenium (Se), and zinc (Zn). Concentrations of individual metals in anurans decreased with increasing weight and developmental stage. In salamanders, which are predatory, metal concentrations were less correlated with weight, indicating diet played a role in contaminant accumulation. Based on batches of similarly sized whole-body larvae compared to larvae with their digestive tracts removed our results indicated that tissue type strongly affected perceived concentrations, especially for anurans (gut represented 50–90% of all metals except Se and Zn). This suggest the reliability of results based on whole body sampling could be biased by metal, larval size, and development. Overall, our data suggest that metal concentrations differs among orders (anuran and salamanders) which suggests that metal accumulation is unique to feeding behavior and potentially trophic position. To truly characterize exposure risk in wetlands, species of different life histories, sizes and developmental stages should be included in biomonitoring efforts.

Publication details
Published Date: 2021-06-26
Outlet/Publisher: Environmental Pollution 287: e117638
Media Format: URL

ARMI Organizational Units:
Southwest, Northern California - Biology
Rocky Mountains, Northern - Biology
Midwest - Biology
Northeast - Biology
Northeast - Water
Topics:
Stressors
Place Names:
California; Missouri; Montana; Northeast U.S.; United States
Keywords:
amphibians; ARMI; mercury; monitoring; stressors; wetlands; zinc
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