River phosphorus cycling during high flow may constrain Lake Erie cyanobacteria blooms.
Water Res
; 222: 118845, 2022 Aug 15.
Article
em En
| MEDLINE
| ID: mdl-35868100
ABSTRACT
Cyanobacterial harmful blooms have been increasing worldwide, due in part to excessive phosphorus (P) losses from agriculture-dominated watersheds. Unfortunately, cyanobacteria bloom management is often complicated by uncertainty associated with river P cycling. River P cycling mediates P exports during low flow but has been assumed to be unimportant during high flows. Thus, we examined interactions between dissolved reactive phosphorus (DRP) and suspended sediment P during high flows in the Maumee River network, focusing on March-June Maumee River DRP exports, which fuel recurring cyanobacteria blooms in Lake Erie. We estimate that during 2003-2019 March to June high flow events, P sorption reduced DRP exports by an average of 13-27%, depending upon the colloidal-PDRP ratio, decreasing the bioavailability of P exports, and potentially constraining cyanobacteria blooms by 13-40%. Phosphorus sorption was likely lower during 2003-2019 than 1975-2002 due to reductions in suspended sediment loads, associated with soil-erosion-minimizing agricultural practices. This unintended outcome of erosion management has likely decreased P sorption, increased DRP exports to Lake Erie, and subsequent cyanobacteria blooms. In other watersheds, DRP-sediment P interactions during high flow could have a positive or negative effect on DRP exports; therefore, P management should consider riverine P cycles, particularly during high flow events, to avoid undermining expensive P mitigation efforts.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Lagos
/
Cianobactérias
Idioma:
En
Revista:
Water Res
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Estados Unidos