Data from figures and tables of "Physical Oceanographic Conditions in the Gulf of St. Lawrence in 2015". Données des figures et tableaux du rapport SCCS « Conditions océanographiques physiques dans le golfe du Saint-Laurent en 2015 ».

The hydrographic 1991 to 2020 climatology for the Maritimes region Atlantic Zone Monitoring Program core transects, Cabot Strait, Louisbourg, Halifax, Browns Bank, and Northeast Channel, are calculated to support annual reporting on seasonal variability. Details on data coverage for these transects and ancillary transects occupied since the inception of the program are provided. Comparisons with the previous climatology period, years 1981 to 2010, are summarized when possible. Cite this data as: Layton, C. Data of: Maritimes Region Atlantic Zone Monitoring Program 1991 to 2020 Hydrographic Transect Climatology. Published: August 2025. Ocean Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/5f9c5d65-3ce1-4bdd-8b43-34086620d1e3

For several years, Fisheries and Oceans Canada (DFO) has conducted annual ship-based surveys in the St. Lawrence Estuary and the Gulf of St. Lawrence to assess environmental conditions and support a range of scientific objectives. Because these surveys do not extend into winter, a complementary regional monitoring program has been implemented annually in early March since 1996. This monitoring program is typically carried out using a Canadian Coast Guard helicopter, although in 2016 and 2017 it was conducted aboard an icebreaker. The winter survey measures physical oceanographic conditions to approximately 200 m depth along with nutrient concentrations in the surface layer. Starting in 2023, the survey was expanded to include phytoplankton measurements. Data from this program are integrated with those from the Atlantic Zone Monitoring Program (AZMP) to produce annual reports including physical (CTD) and biological (bottle) assessments and a Zonal Scientific Advisory for the Gulf of St. Lawrence which can be found on the following webpage under the given year : Atlantic Zone Monitoring Program (AZMP) - https://www.dfo-mpo.gc.ca/science/data-donnees/azmp-pmza/index-eng.html Here, raw data on physical oceanographic conditions, nutrient concentrations and phytoplankton collected during the winter survey are presented. This publication contains three data files: ‘donnees_data_heli_CTD’ which contains links per year to the CTD data, ‘donnees_data_heli_bottle_bouteille’, which contains nutrient data, and ‘donnees_data_heli_phyto’ which contains phytoplankton data. The dataset covers the period of 1996 to present and is updated annually as new data becomes available. Note: this publication contains raw data, please use with caution or contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca) if you have any questions. For further methodological information please see the supporting document for citations. For mean winter surface conditions in the Estuary and Gulf of St. Lawrence please see the following related publication Winter surface conditions – Helicopter survey - Open Government Portal - https://open.canada.ca/data/en/dataset/9a42d891-fc9c-44b3-8fba-9d9ed96890cf