Articles | Volume 20, issue 4
Research article
24 Feb 2023
Research article |  | 24 Feb 2023

Temporal and spatial evolution of bottom-water hypoxia in the St Lawrence estuarine system

Mathilde Jutras, Alfonso Mucci, Gwenaëlle Chaillou, William A. Nesbitt, and Douglas W. R. Wallace

Data sets

Coriolis Hydrographic Dataset Alfonso Mucci and Mathilde Jutras

Short summary
The deep waters of the lower St Lawrence Estuary and gulf have, in the last decades, experienced a strong decline in their oxygen concentration. Below 65 µmol L-1, the waters are said to be hypoxic, with dire consequences for marine life. We show that the extent of the hypoxic zone shows a seven-fold increase in the last 20 years, reaching 9400 km2 in 2021. After a stable period at ~ 65 µmol L⁻¹ from 1984 to 2019, the oxygen level also suddenly decreased to ~ 35 µmol L-1 in 2020.
Final-revised paper