From the website:

The Spatial Data Holdings page provides users with a quick and easy way of scanning the data resources currently held in the GIS Unit's spatial data warehouse. This data has been organized under the following three broad categories:

* Themes: Datasets displaying the spatial distribution of a specific topic (e.g. fish distribution)
* Images: Orthophotos, satellite imagery, raster maps
* Basemaps: Datasets containing geographic features for locational references (e.g. roads)

Additional features have been incorporated into these pages to provide users with further information and improved access to the data holdings. These features include:

Metadata - Access to a textual description of the data's characteristics.

Download - Users can download a selected dataset as an ESRI shapefile directly to their local computer.

As data is constantly being acquired and added to the GIS Unit's spatial data warehouse, users are encouraged to check the What's New page to find out more about the Unit's most recent data acquistions available at the following link: http://www-heb.pac.dfo-mpo.gc.ca/maps/new_e.htm