Microcystins in planktonic and benthic food web components from Greenlandic lakes

• Published in: Ecosphere
• Main Authors: Jessica V. Trout‐Haney, Kathryn L. Cottingham
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2021
• Subjects: aquatic; Arctic; cyanobacteria; cyanotoxins; food webs; Ecology; QH540-549.5; Greenland; greenlandic; Human health; Phytoplankton
• Online Access: https://doi.org/10.1002/ecs2.3539; https://doaj.org/article/e26f3e8186064238a4a78cd2bb8f68f6

Abstract There is increasing global concern regarding the social, economic, human health, and environmental health implications of cyanotoxins. However, much of what we know about cyanotoxins comes from studies of temperate or tropical systems with conspicuous surface blooms of cyanobacteria. We measured the concentrations of microcystins (MCs), potent cyanotoxins produced by many cyanobacterial taxa, within lake food webs in southwestern Greenland. We detected MCs in six taxonomic groups of organisms and found that median MC concentrations in large (>50 µm) phytoplankton were an order of magnitude higher than benthic cyanobacteria (genus Nostoc) and two orders of magnitude higher than benthic grazers and consumers (snails, dytiscid larvae, and chironomid larvae). Microcystin concentrations generally decreased with increasing trophic position, suggesting that biomagnification does not occur in these lakes. We conclude that MCs are prevalent in multiple components of these Arctic aquatic food webs and that both benthic and pelagic taxa may be sources of MCs.