Calcium and strontium stable isotopes reveal similar behaviors of essential Ca and nonessential Sr in stream food webs

• DOI: 10.1002/ecs2.3921
• Publication Date: 2022-02-09T08:24:47Z
• Authors: Kai Nils Nitzsche; Shigeyuki Wakaki; Katsuyuki Yamashita; Ki‐Cheol Shin; Yoshikazu Kato; Hiromitsu Kamauchi; Ichiro Tayasu
• Keywords: Caddisfly; Baetidae; Isotopes of strontium; Periphyton

Abstract Recent studies showed the potential of stable isotopes macronutrient calcium (δ 44/40 Ca) and nonessential strontium 88/86 Sr) as new trophic level indicators in terrestrial vertebrates marine teleost fishes. In this study, we tested whether similar Ca Sr isotopic fractionation trends existed macroinvertebrate‐dominated stream food webs compared to despite their physiological differences. We have determined δ values well 87 Sr/ 86 ratios macroinvertebrates small gobies metal sources (stream water, periphyton, plant litter) upper lower reaches two streams Lake Biwa catchment, central Japan. The revealed that stonefly nymphs, crustacea, mostly relied on aquatic sources. Higher some crane fly caddisfly larvae, mayfly, dobsonfly, dragonfly nymphs indicated greater contributions via litter. Positive correlations between implied existed, underwent although was not essential. partly were positively correlated with Sr/Ca negatively 15 N indicating effects isotopes. enrichment 44 88 large filter‐feeding larvae a notable exception from these trends. Our data confirm depletion observed for fishes also applied different physiologies shared mechanisms may exist at cellular or molecular taxa.