Station 27 (47° 32.8' N, 52° 35.2' W) was established in 1946 as the first hydrographic monitoring station in the standard St. John's to Flemish Cap transect and is the most frequently sampled site in Newfoundland and Labrador waters. Located approximately 7 km off St. John's harbour in a water depth of 176m this station was intentionally located in the Avalon Channel to monitor the water properties of the inshore branch of the Labrador current which are representative of conditions across a broad area of the Newfoundland Shelf. Data was first collected at Station 27 in 1946 and the station was sampled regularly ever since, making it one of the longest hydrographic monitoring stations in the world. In recent years, Station 27 has been sampled about 2 - 4 times per month on average, primarily by oceanographic and fisheries research vessels, as part of the Atlantic Zone Monitoring Program (AZMP).
Due to the length of the hydrographic time series at Station 27 sampling methods vary, and include instrumentation such as water-sampling bottles equipped with reversing thermometers, mechanical and electronic bathythermographs, and more recently conductivity-temperature-depth (CTD) recorders have been used extensively. Therefore the accuracy of the data varies depending on which data collection method was used.
In recent years, data collection at Station 27 has expanded to include a year-round high-resolution temperature-salinity mooring, an acoustic zooplankton fish profiler (AZFP) mooring which is deployed for 9 months each year from November - July, and a Viking buoy (AZMP-STA27) equipped with meteorological and surface oceanographic sensor suite, as well as a profiling CTD winch, which is deployed in late-spring through mid-fall.
