Articles | Volume 20, issue 4
https://doi.org/10.5194/bg-20-839-2023
https://doi.org/10.5194/bg-20-839-2023
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

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Cited articles

Audet, T., de Vernal, A., Mucci, A., Seidenkrantz, M.-S., Hillaire-Marcel, C., Carnero-Bravo, V., and Gélinas, Y.: Benthic foraminifer assemblages from the Laurentian Channel in the Lower Estuary and Gulf of St. Lawrence, eastern Canada: tracers of bottom water hypoxia, J. Foramin. Res., 53, 57–77, https://doi.org/10.2113/gsjfr.53.1.57, 2023. 
Bailey, J. E. and Ollis, D. F.: Applied enzyme catalysis, Biochem. Eng. Fundamentals, 2, 157–227, 1986. 
Belley, R., Archambault, P., Sundby, B., Gilbert, F., and Gagnon, J.-M.: Effects of hypoxia on benthic macrofauna and bioturbation in the Estuary and Gulf of St. Lawrence, Canada, Cont. Shelf Res., 30, 1302–1313, https://doi.org/10.1016/j.csr.2010.04.010, 2010. 
Bindoff, N. L., Cheung, W. W., Kairo, J. G., Arístegui, J., Guinder, V. A., Hallberg, R., Hilmi, N. J. M., Jiao, N., Karim, M. S., Levin, L., O'Donoghue, S., Purca Cuicapusa, S. R., Rinkevich, B., Suga, T., Tagliabue, A., and Williamson, P.: Changing ocean, marine ecosystems, and dependent communities, IPCC special report on the ocean and cryosphere in a changing climate, 477–587, https://eprints.qut.edu.au/206805/ (last access: 14 February 2023), 2019. 
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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.
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