Document Type
Article
Publication Date
3-2026
Department
Department of Biological Sciences
Abstract
Metals are essential for microbial metabolism, yet their role as limiting nutrients in freshwater streams remains poorly understood. We quantified the prevalence of metal and nutrient (co-)limitation of primary producers in 41 streams. Metal limitation was widespread with Fe limitation eliciting the strongest and most consistent biomass responses (50% of streams). Zn limitation was also common (33% of streams), marking the first evidence of Zn-limited stream biofilms at this spatial scale. Metals were often co-limiting with N and P, highlighting interactions between macro- and micronutrients. Diatoms were more responsive to Zn and cyanobacteria reached higher biomass with N and P enrichment, emphasizing divergent nutrient responses among taxa. Predictive modelling indicated that Fe and Zn limitation could be forecasted from environmental variables related to macronutrient supply. These findings challenge the long-standing assumption that stream primary producers are rarely metal-limited and suggest that trace metals may play an underappreciated role in regulating stream productivity, community composition and nutrient cycling.
Publication Title
Ecology Letters
Recommended Citation
Costello, D.,
Akinnifesi, O.,
Schipper, R.,
Kostick, P.,
Stoll, J.,
Tiegs, S.,
Marcarelli, A.,
Entrekin, S.,
Bier, R.,
Capps, K.,
&
Fletcher, D.
(2026).
Anaemic Streams: Iron and Essential Trace Metals Frequently Limit Primary Producer Biomass.
Ecology Letters,
29(3).
http://doi.org/10.1111/ele.70357
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p2/2442
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Version
Publisher's PDF
Publisher's Statement
© 2026 The Author(s). Ecology Letters published by John Wiley & Sons Ltd. Publisher’s version of record: https://doi.org/10.1111/ele.70357