RQM - CTD Data From the Lampsilis Concerted Mission (MAL2019): Odyssée Saint-Laurent 2019

The concerted Lampsilis mission in August to September 2019, funded by the St. Lawrence Odyssey 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 7 projects centred around two major research areas: water quality, and the monitoring of biological communities in the St. Lawrence, in the context of interactions between fresh and salt water.

Vertical profiles of CTD data (conductivity, temperature, depth) were made in the water column at 34 stations in the St. Lawrence River (from the town of Sorel-Tracy) and its Upper Estuary (at the town of Cacouna). These profiles were taken from the surface to an average distance of around 1 m from the seabed. They include measurements of temperature, salinity, density, dissolved oxygen, light transmission, vertical stratification 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 concentrations (63 samples, 37 stations). These comparisons were used to adjust the calibration of fluorescence data from the CTD.