Mercury Isotope Values in Shoreline Spiders Reveal the Transfer of Aquatic Mercury Sources to Terrestrial Food Webs

• DOI: 10.1021/acs.estlett.3c00450
• Publication Date: 2023-09-13T12:01:25Z
• Authors: Sarah E. Janssen; Christopher J. Ko...; Collin A. Eagles-...; Gale B. Beaubien; Joel C. Hoffman; Greg Peterson; Marc A. Mills; David M. Walters
• Keywords: Mercury; Aquatic insect; Terrestrial plant; Predatory fish

The transfer of aquatic contaminants, including mercury (Hg), to terrestrial food webs is an often-overlooked exposure pathway animals. While research has implemented the use shoreline spiders assess Hg transfer, it unclear whether sources, estimated from isotope ratios, can be successfully resolved inform site assessments and remedy effectiveness. To examine we collected (Tetragnatha spp.) insect larvae (suborder Anisoptera) across a mosaic habitats in St. Louis River Bad River, tributaries Lake Superior. fraction industrial sediments was reflected δ202Hg values dragonfly predatory fish, connecting benthic sources web. Shoreline mirrored these source signatures with highly positive correlations between tetragnathids (r2 = 0.90). Further assessment different spider taxa (i.e., araneids pisaurids) revealed that differences prey consumption foraging strategies resulted differences, highlighting importance selection for monitoring efforts.