The main objective of this sampling program was to assess the effects of the spill on the toxicity of surface water collected during the spill by comparing them with the results of water collected prior to the discharge.**This third party metadata element was translated using an automated translation tool (Amazon Translate).**

This theme represents the limit of the Quebec territory of the Agreement on Sustainable Water Resources of the Great Lakes and St. Lawrence River Basin. It was generated from the grouping of watersheds at a cartographic scale of 1:20,000. For more information: http://www.environnement.gouv.qc.ca/eau/grandslacs/2005/index.htm**This third party metadata element was translated using an automated translation tool (Amazon Translate).**

As part of measure 2.6 of the 2013-2020 Climate Change Action Plan, the MELCC financed two projects specific to the St. Lawrence river section and aimed at supporting municipalities facing the risks of erosion and flooding. The team of the **Laboratoire de Géomorphology Terre-Mer du Département de Géomorphology de l'Université Laval** has set up an essential geospatial information base for assessing the risks associated with the erosion of the banks of the banks of the St. Lawrence river section. The user will be able to find there (i) the mapping of the classification of the shore (types of banks and their artificialization), (ii) the degradation conditions of artificial structures and (iii) the state of erosion of natural or artificial segments. The sectors most vulnerable to erosion have also been mapped and documented with image quality sheets. These sheets present the characteristics of the shoreline and the main natural (currents, ice, etc.) and human geomorphological processes (currents, ice, etc.) associated with bank erosion for these nerve sectors, in order to better represent local dynamics. The geospatial data associated with shoreline mapping, the quality sheets and the project report, which includes the description of the methodology and results, are available for download. The second project is led by Ouranos and aims to reduce the vulnerability to floods and erosion associated with climate change for communities bordering the St. Lawrence river section. The user will be able to consult two reports resulting from this project: a. Technical report on future trends in the main hydro-climatic factors that influence natural flood risks and bank erosion processes along the fluvial section of the St. Lawrence. The objectives of this report are to draw a portrait of these hazards, covering both the recent past and future projections (2050 and 2080). These factors range from large-scale phenomena, such as the spring flood of the St. Lawrence River or marine uplift, to local phenomena such as freeze-thaw processes that affect clay cliffs and microcliffs. b) Summary of the needs mentioned by the actors of the regional round tables (TCRs) to adapt shoreline communities to the risks of bank erosion and flooding. This report presents a portrait of the participants of the four workshops organized in the fall of 2018, the approach used for the consultation and a summary of the needs expressed. The lists of participants and the detailed reports of each workshop are also included in the annex to this document. The TCRs consulted during these workshops are those of Haut-Saint-Laurent — Greater Montreal, Lac Saint-Pierre, the fluvial estuary and the TCR of Quebec. Following this characterization project, a [Study of bank mobility issues in the St. Lawrence river section] project (https://www.donneesquebec.ca/recherche/dataset/etude-d-enjeux-de-mobilite-des-berges-dans-le-troncon-fluvial-du-saint-laurent) was carried out.**This third party metadata element was translated using an automated translation tool (Amazon Translate).**

Lake sturgeon's presence zones, breeding, feeding and concentration areas according to a literature review of documents produced between 1976 and 2002.Data extracted from the Fish Habitat Management Information System (FHAMIS).

Species characterization by environmental DNA (eDNA) is a method that allows the use of DNA released into the environment by organisms from various sources (secretions, faeces, gametes, tissues, etc.). It is a complementary tool to standard sampling methods for the identification of biodiversity. This project provides a list of fish and marine mammal species whose DNA has been detected in water samples collected between 2019 and 2021 using the mitochondrial marker MiFish (12S). The surveys were carried out in the summer of 2019 (July 14-18) and (July 30 - August 5), in the fall of 2020 (October 27-28) and in the summer-fall of 2021 (May 31 - June 3 ) and (August 24-25) between Forestville and Godbout (Haute-Côte-Nord). Sampling was carried out between 1-50 meters depth in 91 stations, with 1 to 3 replicates per station. Two liters of water were filtered through a 1.2 µm fiberglass filter. DNA extractions were performed with the DNeasy Blood and Tissues or PowerWater extraction kit (Qiagen). Negative field, extraction and PCR controls were added at the different stages of the protocol. The libraries were prepared either by Génome Québec (2019, 2020) or by the Genomics Laboratory of the Maurice-Lamontagne Institute (2021), then sequenced on a NovaSeq 4000 PE250 system by Génome Québec. The bioinformatics analysis of the sequences obtained was carried out using an analysis pipeline developed in the genomics laboratory. A first step made it possible to obtain a table of molecular operational taxonomic units (MOTU) using the cutadapt software for the removal of the adapters and the R package DADA2 for the filtration, the fusion, removal of chimeras and compilation of data. The MOTUs table was then corrected using the R package metabaR to eliminate the tag-jumping and take contaminants into consideration. Samples showing a strong presence of contaminating MOTUs were removed from the dataset. The MOTUs were also filtered to remove all remaining adapter sequences and also retain only those of the expected size (around 170 bp). Finally, taxonomic assignments were made on the MOTUs using the BLAST+ program and the NCBI-nt database. Taxonomic levels (species, genus or family) were assigned using a best match method (Top hit), with a threshold of 95%. Only assignments at the level of fish and marine mammals were considered, and the taxa detected were compared to a list of regional species, and corrected if necessary. The species detections of the different replicas have been combined. The file provided includes generic activity information, including site, station name, date, marker type, assignment types used for taxa identification, and a list of taxa or species. The list of taxa has been verified by a biodiversity expert from the Maurice-Lamontagne Institute. This project was funded by Fisheries and Oceans Canada's Coastal Environmental Baseline Data Program under the Oceans Protection Plan. This initiative aims to acquire baseline environmental data that contributes to the characterization of significant coastal areas and supports evidence-based assessments and management decisions to preserve marine ecosystems. Data were also published on SLGO platform : https://doi.org/10.26071/ogsl-2239bca5-c24a

Species characterization by environmental DNA (eDNA) is a method that allows the use of DNA released into the environment by organisms from various sources (secretions, faeces, gametes, tissues, etc.). It is a complementary tool to standard sampling methods for the identification of biodiversity. This project provides a list of invertebrates species whose DNA has been detected in water samples collected at 2018 using the marker COI. The surveys were carried out in the summer of 2018 from August 11 to 14, between Forestville and Godbout (Haute-Côte-Nord). Sampling was carried out between 9-52 meters depth in 40 stations with one sample par station. Two liters of water were filtered through a 1.2 µm fiberglass filter. DNA extractions were performed with the DNeasy Blood and Tissue extraction kit (Qiagen). Negative field, extraction and PCR controls were added at the different stages of the protocol. Libraries at the COI locus were prepared by Genome Quebec and sequenced on an Illumina MiSeq PE250 system. The bioinformatics analysis of the sequences obtained was carried out using an in-house analysis pipeline as reported in Bourret et al. 2022. A first step made it possible to obtain a molecular operational taxonomic unit table (MOTU) using the cutadapt software for the removal of the adapters and the DADA2 R package for the filtration, fusion, chimera removal and data compilation. The MOTUs table was subsequently corrected by taking into account the negative controls, where the number of observations in the latter was removed from the linked samples. Singleton MOTUs have also been removed. Finally, the taxonomic assignments were carried out on the MOTUs using the IDTAXA classifier (present in the DECIPHIER R package) using a training set trained on the COI reference bank for Golf St-Laurent (GSL-rl v1.0, https://github.com/GenomicsMLI-DFO/MLI_GSL-rl) and a threshold of 40. Detections with an “Unreliable due to gaps” category were reported at the genus level only. The file provided includes generic activity information, including site, station name, date, marker type, assignment types used for taxa identification, and a list of taxa or species. The list of taxa has been verified by a biodiversity expert from the Maurice-Lamontagne Institute. This project was funded by Fisheries and Oceans Canada's Coastal Environmental Baseline Data Program under the Oceans Protection Plan. This initiative aims to acquire baseline environmental data that contributes to the characterization of significant coastal areas and supports evidence-based assessments and management decisions to preserve marine ecosystems. Data are also available on SLGO platform : https://doi.org/10.26071/ogsl-cd4c205b-f63b

The layer provides information on suspended particulate matter (SPM) concentrations by area. There is a natural interaction phenomenon between hydrocarbons and SPM, that creates hydrocarbon-SPM aggregates. The SPM in the water column, hence has an effect on hydrocarbon capacity to sink to the bottom in aggregate form (Gong et collab., 2014 ; Fitzpatrick et collab., 2015, cited in Centre d'expertise en analyse environnementale du Québec, 2015). Additional Information The suspended particulate matter data for this layer are derived from multiple sources given the need to cover the St. Lawrence portion from Montreal to Anticosti. The layer has been cut into 6 different zones. Denis Lefaivre, a researcher at Maurice-Lamontagne Institute, has provided the coordinates of the points allowing the delimitation of areas. The values in each zone are derived from different studies carried out at different times. The references are cited below for each of the polygons from West to East, as well as for the summary: 1- Department of Sustainable Development, Environment and Climate Change and Environment and Climate Change Canada, 2016. Recommendations for Suspended Matter Management (ESM) during dredging activities. Quebec. 64 pages and appendices. http://planstlaurent.qc.ca/fileadmin/publications/diverses/Registre_de_dragage/Recommandations_dragage.pdf 2- D'Anglejan, B. 1990. Recent Sediments and Sediment Transport Process in the St. Lawrence Estuary. In Oceanography of a Large-Scale Estuarine System: The St. Lawrence, edited by M. I. El-Sabh and N. Silverberg. New York: Springer-Verlag, 109- 153. 3- Silverberg, N., and B. Sundby. 1979. Observations in the maximum turbidity of the St. Lawrence estuary. Can. J. Earth Sci. 16: 939-950. 4- Michel Lebeuf, 2016.Unpublished personal data.Collected between 2015-2016 for research purposes. 5- Sundby, B. 1974. Distribution and Transport of Suspended Particulate Matter in the Gulf of St. Lawrence. Canadian Journal of Earth Sciences11 (11): 1517-1533. 6- Gong, Y., X. Zhao, Z. Cai, S. E. O'Reilly, X. Hao and D. Zhao. 2014. A review of oil, dispersedoil and sediment interactions in the aquatic environment: Influence on the fate, transportand remediation of oil spills. Marine Pollution Bulletin, vol. 79: 1-2, p.16-33. 7- Fitzpatrick, F.A., M.C., Boufadel, R., Johnson, K., Lee, T.P., Graan, A.C., Bejarano, Z.,Zhu, D., Waterman, D.M., Capone, E., Hayter, S.K., Hamilton, T., Deffer, M.H.,Garcia, et J.S., Hassan. 2015. Oil-particle interactions and submergence from crudeoil spills in marine and freshwater environments – Review of the science and futurescience needs. U.S. Geological Survey Open-file report 2015-2016, 33 p. 8- Centre d'expertise en analyse environnementale du Québec,2015.Hydrocarbures pétroliers : caractéristiques, devenir et criminalistique environnementale –Études GENV222 et GENV23, Évaluation environnementale stratégique globale sur leshydrocarbures. Ministère du Développement durable, de l’Environnement et de la Lutte contreles changements climatiques, 41 p. et annexes. 9- CSL – Centre Saint-Laurent, 1997. Le Saint-Laurent : dynamique et contamination des sédiments, Montréal, Environnement Canada – Région du Québec, Conservation de l’environnement, 127 p. (coll. BILAN Saint-Laurent). [Rapport thématique sur l’état du Saint-Laurent].

This theme presents the index of water health along the banks of the St. Lawrence River. It makes it possible to determine if the sites present risks to human health and if they are suitable for swimming. These data are the result of an exploratory monitoring program that aims to raise awareness among the population and local actors about the possible reopening of bathing sites that have good potential. This program also makes it possible to highlight any improvement in bacteriological quality resulting from the reduction of wastewater overflows during rainy weather or resulting from the installation of disinfection equipment.**This third party metadata element was translated using an automated translation tool (Amazon Translate).**

This dataset contains the surface temperature and salinity data of the enlarged coastal thermograph network of the St. Lawrence river, estuary and gulf system. It includes data from the Canadian Hydrographic Service water level network (SINECO), the Department of Fisheries and Oceans (DFO)-Quebec long-termed thermograph monitoring program network and the oceanographic buoy network. Each station is linked with a .png file showing the temperature and salinity time series and with a .csv file containing the surface temperature and salinity data themselves (columns : Station,Latitude,Longitude,Date(UTC),Depth/Profondeur(m),Temperature/Température(ºC),Salinity/Salinité(psu)). Supplemental Information A detailed description of the networks (SINECO, oceanographic buoys and the DFO-Quebec thermograph monitoring program) is available at the St. Lawrence Global Observatory (SLGO) portal : SINECO : https://ogsl.ca/en/tide-gauges-dfo-chs/ Oceanographic buoys : https://ogsl.ca/en/marine-conditions-buoys-dfo/ Thermographs: https://ogsl.ca/en/marine-conditions-thermographs-dfo/ Technical Reports related to the Thermograph Network (the last one is also available at the same hypertext link mentionned above) : Pettigrew, B., Gilbert, D. and Desmarais R. 2016. Thermograph network in the Gulf of St. Lawrence. Can. Tech. Rep. Hydrogr. Ocean Sci. 311: vi + 77 p. Pettigrew, B., Gilbert, D. and Desmarais R. 2017. Thermograph network in the Gulf of St. Lawrence: 2014-2016 update. Can. Tech. Rep. Hydrogr. Ocean Sci. 317: vii + 54 p.

The Copper Redhorse (Moxostoma hubbsi) is the only fish whose distribution is exclusively restricted to Quebec. This range is restricted even further to the St. Lawrence River and some of its tributaries. This layer represents the Copper Redhorse critical habitat defined by the analysis of available knowledge and a scientific advice. Purpose The Copper Redhorse population is in decline due to several threats like habitat degradation, construction of dams, contaminants, exotic or introduced species, recreational activities, commercial fishery, and low water levels. Furthermore, certain biological characteristics of the Copper Redhorse contribute to its vulnerability. The Copper Redhorse population was officialy listed as endangered in Schedule I of the Species at Risk Act in December 2007. Additional Information Critical habitat for the Copper Redhorse has been identified to the extent possible, based on the best available information. Two workshops held in 2009 and 2010 by Fisheries and Oceans Canada and the Ministère des Ressources Naturelles et de la Faune du Québec, allowed to review the information and take note of the new data to identify habitat use by the Copper Redhorse in the St. Lawrence and Richelieu rivers and later in the Rivière des Prairies and Rivière des Milles Îles. Adult feeding habitat in the St. Lawrence River between Lake Saint-Louis and Lake Saint-Pierre, was identified using modeling based on the telemetric monitoring of habitat use and on twelve habitat variables (for example: depth, current velocity, vegetation density). Also, recent telemetry and historic data confirmed the use of the lower stretches of the Rivière des Prairies and Rivière des Mille Îles. Critical adult feeding habitat is consequently identified as habitat in the fluvial reach between Montreal and Sorel presenting favorable characteristics for the copper redhorse, used in the model. DFO. 2012. Recovery Strategy for the Copper Redhorse (Moxostoma hubbsi) in Canada. Species at Risk Act Recovery Strategy Series. Fisheries and Oceans Canada, Ottawa. xi+60 pp. https://www.registrelep-sararegistry.gc.ca/document/doc1565p/ind_e.cfm