Influence of a small submarine canyon on biogenic matter export flux in the lower St. Lawrence Estuary, eastern Canada

Sharpe, Hannah; Gosselin, Michel; Lalande, Catherine; Normandeau, Alexandre; Montero-Serrano, Jean-Carlos; Baccara, Khouloud; Bourgault, Daniel; Sherwood, Owen; Limoges, Audrey

doi:https://doi.org/10.5194/bg-20-4981-2023

Articles | Volume 20, issue 24

https://doi.org/10.5194/bg-20-4981-2023

© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/bg-20-4981-2023

© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 20, issue 24

Research article

|

18 Dec 2023

Research article |

| 18 Dec 2023

Influence of a small submarine canyon on biogenic matter export flux in the lower St. Lawrence Estuary, eastern Canada

Hannah Sharpe, Michel Gosselin, Catherine Lalande, Alexandre Normandeau, Jean-Carlos Montero-Serrano, Khouloud Baccara, Daniel Bourgault, Owen Sherwood, and Audrey Limoges

Data sets

Time-series biogenic matter export fluxes offshore Pointe-des-Monts and Baie-Comeau H. Sharpe, M. Gosselin, C. Lalande, A. Normandeau, J.-C. Montero-Serrano, K. Baccara, D. Bourgault, O. Sherwood and A. Limoges https://doi.org/10.26071/ogsl-9b07076f-e47b

Short summary

We studied the impact of submarine canyon processes within the Pointe-des-Monts system on biogenic matter export and phytoplankton assemblages. Using data from three oceanographic moorings, we show that the canyon experienced two low-amplitude sediment remobilization events in 2020–2021 that led to enhanced particle fluxes in the deep-water column layer > 2.6 km offshore. Sinking phytoplankton fluxes were lower near the canyon compared to background values from the lower St. Lawrence Estuary.