PT  - JOURNAL ARTICLE
AU  - Whitney M. King
AU  - Susan E. Curless
AU  - James M. Hood
TI  - River phosphorus cycling constrains lake cyanobacteria blooms
AID  - 10.1101/2021.05.03.442426
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.05.03.442426
4099  - http://biorxiv.org/content/early/2021/05/03/2021.05.03.442426.short
4100  - http://biorxiv.org/content/early/2021/05/03/2021.05.03.442426.full
AB  - Bioavailable phosphorus exports from rivers during high flow often fuel downstream harmful cyanobacterial blooms; yet whether river phosphorus cycles affect these exports is unclear. Here, we examined river phosphorus cycling during high flow events in a large agricultural watershed that drives cyanobacterial blooms in Lake Erie. We show that between 2003 and 2019 river phosphorus cycles, through phosphorus sorption, reduced bioavailable phosphorus exports by 24%, potentially constraining Lake Erie cyanobacterial blooms by 61%. Over the last 45-years, phosphorus sorption has declined with suspended sediment exports due to increases in soil-erosion-minimizing agricultural practices, likely contributing to recent cyanobacterial blooms. In this, and likely other agricultural watersheds, rivers perform an unrecognized ecosystem service during high flow creating field-river-lake linkages that need to be incorporated into phosphorus management.Competing Interest StatementThe authors have declared no competing interest.