CTD Data from the 2023 BioDiv Cruise in the Gulf of St. Lawrence

The aim of the BioDiv (id : 2023_09) mission is to characterize phytoplankton and zooplankton in the coastal zone of the northwestern Gulf of St. Lawrence.

As part of this mission, CTD (conductivity, temperature, depth) vertical profiles were carried out at 4 sites, each comprising 4 stations, between Baie-Trinité and Sept-Iles (Quebec North Shore). The CTD was also equipped with sensors to measure dissolved oxygen, turbidity and pH in the water column.

In addition, discrete water samples were taken at various stations and depths (surface for all stations, intermediate and bottom when depth is greater than 10m) to provide additional information on the water masses (concentrations of nutrients NO2+NO3, PO4, SiO2, dissolved and total carbon, chlorophyll a and phaeopigment, concentration of phycotoxins, concentration of bacteria, pico- and nanoplankton, flagellates).

Phytoplankton were also sampled using a 20µm net and Niskin bottles. Different size classes of zooplankton were collected with 63µm, 200µm and 500µm nets.

This dataset is part of the EDMS-ISMER-QO collection, as well as the Coastal Environmental Baseline Program Initiative under the Oceans Protection Plan of Fisheries and Oceans Canada.