RQM - CTD Data From the Lampsilis Concerted Mission (MAL2022): State of Health of the St. Lawrence 2022, 3rd Edition

The Lampsilis concerted mission of August 2022, funded by the Odyssée Saint-Laurent program of the Réseau Québec maritime (RQM), aimed to gather strategic scientific knowledge for the understanding and management of the St. Lawrence River and Gulf. This mission enabled a wide-ranging acquisition of multidisciplinary data for 12 projects focusing on changes in biodiversity and water quality from the river's estuarine transition zone to the St. Lawrence Estuary.

Vertical profiles of CTD data (conductivity, temperature, depth) were made in the water column at 30 stations in the St. Lawrence River (from Quebec City) and its Upper Estuary (at Cacouna). These profiles were taken from the surface to an average distance of around 2 m from the seabed. They include measurements of temperature, salinity, density, dissolved oxygen, light transmission, vertical stratification, turbidity and sound velocity in seawater. Discrete water samples were taken at various stations and depths to compare CTD's direct measurements with laboratory analyses of chlorophyll a concentration (63 samples, 37 stations). These comparisons were used to adjust the calibration of fluorescence data from the CTD probe.