DFO Unit Areas, Atlantic Canada

Fisheries and Oceans Canada (DFO) statistical unit areas (also referred to as unit areas) are smaller portions of the Northwest Atlantic Fisheries Organization (NAFO) Subareas, Divisions, and Subdivisions defined in the Convention on Cooperation in the Northwest Atlantic Fisheries (2020). The spatial representation of boundaries defined by NAFO has recently been updated to address inconsistencies and errors in earlier versions, which is available here: https://open.canada.ca/data/dataset/59af1c96-fc8f-4fa0-b398-d65e953eadaa#comment-41855. Unit areas are used by DFO for a variety of purposes including, but not limited to stock assessments, privacy screening of fisheries maps, and statistical analyses.

Unit areas were originally defined throughout the 1940s and 1950s. Subsequently, several revisions and alternate versions were created by DFO in various regions leading to inconsistencies in spatial extent and naming conventions. These changes have not been formally documented. The datasets often have topological errors such as gaps and overlaps, especially along diagonals and coastlines. In addition, inconsistencies have arisen from conflicting interpretations of the NAFO divisions, where not all land points are defined by coordinates. Therefore, DFO, with input from the Canadian Hydrographic Service (CHS), has created an updated version of the DFO unit areas file to address inconsistencies and errors among previous versions. The recently updated NAFO divisions were used as the basis for an updated DFO unit areas file.

This version of the DFO unit areas must not be used for legal purposes. Legal descriptions of fishing area boundaries can be found in the Atlantic Fisheries Regulations, Maritime Provinces Fishery Regulations, and DFO License Conditions.