The oil fate and behaviour visual guides, along with oil vulnerability conceptual models, were developed by the Fisheries and Oceans Canada (DFO) Pacific Region Science Spill Response Program in collaboration with DFO species experts, DFO Emergency Response Science, and the Centre for Offshore Oil, Gas and Energy Research (COOGER). These visual tools assist DFO Environmental Incident Coordinators (EICs), recovery coordinators, response organizations, and other stakeholders to understand the fate, behaviour, exposure pathways, and ecological effects of petroleum products released into the marine environment. Additionally, these tools guide strategies for protection, sampling, and monitoring in areas affected by marine pollution incidents.
Oil fate and behaviour visual guides
These visual guides illustrate the key fates and weathering processes of Bunker C and marine diesel—such as spreading, evaporation, emulsification, dispersion, dissolution, sedimentation, sinking, photo-oxidation, shoreline interaction, biological uptake, and biodegradation. These visuals provide timelines for different fate pathways (e.g., hours to days, days to weeks, or weeks to months) and highlight environmental factors (e.g., wind, wave energy) that influence oil behaviour and weathering processes. By illustrating these processes, the guides support science-based decision-making and the development of targeted oil spill management strategies.
Oil vulnerability conceptual models
The oil vulnerability conceptual models, based on the major Pacific ecosystems identified by Jeffery et al. (2023) and DFO’s vulnerability framework (DFO 2023), represent the broader ecological context of species vulnerable to oil spills. These models were adapted from conceptual models of Canada’s Pacific Ocean ecosystems, originally designed to document key ecological components, interactions, environmental drivers, and human activities
Each model illustrates the main ecological components, reflecting the species subgroups scored through the vulnerability framework, which assesses species risk to oil based on exposure, sensitivity, and recovery criteria. Species subgroups, comprised of organisms with similar characteristics and life histories, are scored on a scale from 0 to 10. Subgroups scoring 7 or above are designated as highly vulnerable to oil. The models reflect the acute effects of direct crude oil contact in worst-case scenarios, excluding indirect, food web, or cumulative impacts. Terrestrial mammals and birds, though ecologically significant, are not included due to lack of scoring data.
Oil vulnerability concept models were developed for nine of the thirteen Pacific ecosystems identified by Jeffery et al. (2023), covering rocky and soft intertidal shores, subtidal zones, pelagic regions, estuaries, and fjords—ecosystems particularly susceptible to oil spills. They provide insight into where oil may persist in each ecosystem and highlight six key species impacts resulting from oil exposure: photosynthetic impairment, habitat loss, mechanical impairment, toxic effects, thermoregulation loss, and oil vapor toxicity.
The integration of these models with the vulnerability framework offers a comprehensive approach to understanding and mitigating oil spill impacts in Canada’s Pacific Ocean. By identifying and prioritizing the most vulnerable species and ecosystems, responders can make science-informed decisions and plan strategies to protect the vulnerable marine species and habitats.