Canine Oil Detection (K9-SCAT) following 2015 Releases from the T/V Arrow Wreck

Abstract

Abstract The T/V Arrow sank in 1970, spilling Bunker C fuel oil into Chedabucto Bay, Nova Scotia. In the summer and fall of 2015, residual oil leaked from the sunken vessel and re-oiled shorelines in the Bay. A K9-SCAT field study, funded by Environment and Climate Change Canada (ECCC), was conducted in June 2016 to assess the capability of detection canines to locate stranded oil following the new releases. The canine detected small amounts of weathered surface oil that were barely visible, and in some cases, not visible, to the SCAT-trained observers, as well as subsurface oil on mixed- and coarse-sediment beaches. The average speed of a survey, in terms of the length of shoreline covered, varied depending on the shore type and the width of the survey band. The most challenging site was a steep bedrock shoreline with an alongshore survey rate of 0.2 linear km/hour. Typical alongshore coverage rates for the wide, mixed sediment were in the range 0.7 to 1.2 linear km/hour, and for both straight, wide sand beaches were 1.2 km/hour. The highest alongshore rate was 2.4 linear km/hour for the narrow beach on Janvrin Island. The successful detection of 2015 T/V Arrow cargo oil (both naturally stranded and intentionally planted) on selected Chedabucto Bay shorelines indicates that there is a low risk, high confidence level that the canine did not miss subsurface oil, although that possibility may exist. Where the canine made an alert and no surface oil was visible, chemical analyses of sediment samples indicated that weathered petroleum hydrocarbons were present at those locations and, therefore, the canine had made correct alerts. The results provide further “proof of concept” for K9-SCAT teams to support surface and subsurface oil detection during traditional shoreline assessment surveys.