Application à la région des Maritimes du cadre national d'évaluation de la vulnérabilité des composantes biologiques aux déversements d'hydrocarbures provenant de navires dans le milieu marin

Abstract

Fisheries and Oceans Canada (DFO) Maritimes Science completed a regional application of the National Framework to Assess the Vulnerability of Biological Components to Ship source Oil Spills in the Marine Environment to support timely and informed response to ship source oil spills in this region. The framework uses a structured method to identify the biological components most vulnerable to direct effects of ship-source oil spill. This is based on a suite of standard screening and ranking criteria that considers direct effects. A total of 1,034 marine species were assessed and merged into 116 taxonomic sub-groups. These sub-groups represent the suite of marine biota in this region with sufficient discrimination to score against nationally standardized vulnerability criteria. This application applied the “Subtidal” classification across all depths within the region, with no discrete “Off Shelf” category, which resulted in only one classification region-wide. This application provided an ecologically and taxonomically based list for all Maritimes Region sub-groups, validated through a literature review, ranked by total vulnerability to ship-source oil spills, which can be used to inform response planning efforts. Of the 116 sub-groups identified, 49 were considered “highly vulnerable”, receiving overall vulnerability scores of 7 or higher (22 received a score of 7; 18 subgroups received a score of 8; and 9 subgroups received a score of 9). Analysis suggested that some biological groups in the National Framework would require changes to sub-group breakdown for application in the Maritimes (i.e., marine fishes and marine algae/plants), whereas other biological groups while other groups would require very little change from the National framework (e.g., marine invertebrates). In some cases, additional sub-group levels, reorganization of existing sub-groups, and the addition of new sub-groups would allow for regionally relevant scoring. Precautionary scoring in instances where information was limited or conflicting identified data gaps and opportunities for future investigation. The sensitivity criterion ‘impairment due to toxicity’ was not effective at differentiating between sub-groups. The “mechanical sensitivity” criterion allowed for further breakdown, but the two conditions were considered to be narrow in scope (i.e., reduction in feeding/photosynthesis and thermoregulation), increasing the potential for underscoring. Further development of the sensitivity category was recommended. Based on expert opinion during the meeting, the population status criterion was expanded (i.e., to include more nformation sources related to decline) to more fully meet the “population status” criteria definition as laid out in the national framework. This application is meant to be used in conjunction with other science tools and data (spatial and non-spatial) to support evidence-based decision making during the response to marine oil spills; more specifically, to be used to support environmental mitigation prioritization discussions.