Polycyclic aromatic hydrocarbons data in sediments from the Estuary and Gulf of St. Lawrence (eastern Canada)

The St. Lawrence Estuarine System is a major seaway connecting eastern Canada with the Atlantic Ocean. Approximately 4000 vessels travel along this seaway every year that contribute, in addition to industrial activities, to anthropogenic stress in regard to many pollutants, including polycyclic aromatic hydrocarbons (PAHs). In this study, the concentrations of 23 PAHs (16 parent PAHs and 7 alkyl-PAHs), total organic carbon (TOC) as well as grain-size distributions were determined in 45 surface sediment and 7 basal sediment box core samples retrieved from the Estuary and Gulf of St. Lawrence in eastern Canada. All samples were retrieved during the 2018, 2019, and 2020 Odyssée St-Laurent winter expeditions (referred to as AMD18-OSL, AMD19-OSL, and AMD20-OSL, respectively) onboard the Canadian Coast Guard Ship icebreaker Amundsen and the 2020 Québec Maritime Network (Réseau Québec Maritime or RQM)-Marine Environmental Observation Prediction and Response Network (MEOPAR) expedition onboard the research vessel Coriolis II (referred to as COR2001).

Surface sediments (uppermost 0.5 to 1 cm) were collected with a spoon and stored in plastic bags (WhirlPack) at 4°C until further analysis. Push cores were collected by pushing a plexiglass tube (10-cm diameter) into sediments. The cores were stored at 4°C until further subsampling. The data set includes: sample locations, PAHs and TOC content in every sample, PAH ratios (Fla/Fla+Py; BaA/BaA+Ch) and grain size distributions. These baseline data could be of great value for resource management of the marine areas in the Estuary and Gulf of St. Lawrence.