Revisiting global trends in freshwater insect biodiversity
Baranov, Viktor
Altermatt, Florian
Cranston, Peter
Friedrichs‐Manthey, Martin
Geist, Juergen
He, Fengzhi
Heino, Jani
Hering, Daniel
Hölker, Franz
Jourdan, Jonas
Kalinkat, Gregor
Kiesel, Jens
Leese, Florian
Maasri, Alain
Monaghan, Michael T.
Schäfer, Ralf B.
Tockner, Klement
Tonkin, Jonathan D.
Domisch, Sami
DOI: https://doi.org/10.23689/fidgeo-4032
Altermatt, Florian; 4 Department of Evolutionary Biology and Environmental Studies University of Zurich Zürich Switzerland
Cranston, Peter; 6 Australian National University Canberra Australian Capital Territory Australia
Friedrichs‐Manthey, Martin; 1 Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin Germany
Geist, Juergen; 8 Aquatic Systems Biology Technical University of Munich, TUM School of Life Sciences Freising Germany
He, Fengzhi; 1 Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin Germany
Heino, Jani; 9 Freshwater Centre Finnish Environment Institute Oulu Finland
Hering, Daniel; 10 Aquatic Ecology University of Duisburg‐Essen Essen Germany
Hölker, Franz; 1 Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin Germany
Jourdan, Jonas; 11 Department of Aquatic Ecotoxicology Institute for Ecology, Evolution and Diversity, Goethe University Frankfurt am Main Frankfurt am Main Germany
Kalinkat, Gregor; 1 Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin Germany
Kiesel, Jens; 1 Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin Germany
Leese, Florian; 12 Aquatic Ecosystem Research University of Duisburg‐Essen Essen Germany
Maasri, Alain; 1 Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin Germany
Monaghan, Michael T.; 1 Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin Germany
Schäfer, Ralf B.; 13 Institute for Environmental Sciences, Quantitative Landscape Ecology University of Koblenz‐Landau Landau Germany
Tockner, Klement; 1 Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin Germany
Tonkin, Jonathan D.; 15 School of Biological Sciences University of Canterbury Christchurch New Zealand
Domisch, Sami; 1 Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin Germany
Abstract
A recent global meta‐analysis reported a decrease in terrestrial but increase in freshwater insect abundance and biomass (van Klink et al., Science 368, p. 417). The authors suggested that water quality has been improving, thereby challenging recent reports documenting drastic global declines in freshwater biodiversity. We raise two major concerns with the meta‐analysis and suggest that these account for the discrepancy with the declines reported elsewhere. First, total abundance and biomass alone are poor indicators of the status of freshwater insect assemblages, and the observed differences may well have been driven by the replacement of sensitive species with tolerant ones. Second, many of the datasets poorly represent global trends and reflect responses to local conditions or nonrandom site selection. We conclude that the results of the meta‐analysis should not be considered indicative of an overall improvement in the condition of freshwater ecosystems. This article is categorized under: Water and Life > Conservation, Management, and Awareness
Relying on abundance or biomass and examining nonrepresentative datasets limits our ability to infer the condition of freshwater insect communities globally. Photo by Jeremy Monroe, Freshwaters Illustrated: a caddisfly larva from an Oregon Coastal stream, USA (Limnephilidae: Dicosmoecus sp.).