CBC news is reporting that a naval intelligence officer was arrested for disclosing information to foreign entities. Lt.Jeffrey Paul Delisle is reportededly tasked with monitoring shipping movements in the North Atlantic, and is based HMCS Trinity, which is housed within the Halifax Dockyard.

The navy monitors shipping movements in and out of Canadian Waters. This is done both via satellite and via P3 Auora aircraft. Vessels entering Canadian waters are required to report 24 hours in advance. This maritime surveillance can detect illegal dumping and fishing, as well as smugglers.

Update: speculation. Reports suggest that the information was leaked to the Russians. According to Wikipedia, one of the functions that was transferred to HMCS Trinity was the operation of the sub sea surveillance network, which was jointly developed with the US Navy during the cold war to detect foreign submarines. It was operated from CFS Shelburne, which closed in 1995.

Since the network can detect submarine movements, and it was jointly developed with the US Navy, presumably Canadian naval intelligence knows the positions of US Navy, and Possibly British submarines in the North Atlantic – which would certainly be of interest to the Russians.