Assessing the Capabilities of Oil Detection Canines to Detect Submerged Weathered Oils in a Boreal Lake

The efficacy of oil spill response depends on the speed of detecting the oil. Detecting submerged oil is more difficult than oil on the water surface, because most conventional sensors are not effective. Oil Detection Canines (ODCs) have been reliably used to detect oil during shoreline spill surveys, and preliminary laboratory studies also showed promising results for detecting oil submerged under water. To confirm their potential, a field study was conducted in a boreal freshwater lake in Northwestern Ontario, Canada to investigate the capability of an ODC to detect submerged weathered oils at depths of 1 to 5 m. Triplicate targets at each depth used weathered diluted bitumen (dilbit), Bunker C residual fuel oil, and Maya crude oil burn residue and both the ODC and handler blinded to the location of each target. Boat-based searches were conducted and the handler identified “alerts” based on ODC behaviour changes that were compared to georeferenced oil target locations. The ODC positively identified seven (7) of the eight (8) dilbit targets at 1 to 5 m, five (5) of the six (6) Bunker C targets at 1 and 3 m, and none of the burn residue targets at 1-m depth. The ability of ODCs to detect submerged or sunken oil in shallow water was clearly demonstrated, adding another technique for submerged and sunken oil surveys with the advantages of real-time data returns, the ability to detect small oil deposits, and an operational capability in shallow waters with potential for detection in deeper water.