The effects of oil spill dispersant use on marine birds: a review of scientific literature and identification of information gaps

Dispersants, a class of chemical spill-treating agents used to treat oil spills, are commonly globally as an alternative response measure. Applying dispersants slick, shortly after the spill has occurred, can protect shoreline environments and sea surface-dwelling animals, such some marine bird species, limiting individuals or local populations from consequences coming into contact with large quantities oil. However, this benefit comes cost increasing exposure risk biota that spend time in water column. It is generally believed benefits dispersant use outweigh costs under most circumstances. it rarely acknowledged may have negative impacts on at individual population level, including birds. In Canada, Corexit EC9500A, regulated dispersant, being proposed for expanded beyond treating spills offshore gas facility. To understand what potential birds, we conducted literature review identify direct indirect effects their use. We also provide responders Pathway Effects (POE) conceptual model, tool understanding interactions between dispersants, environment support holistic consideration part decision-making process. Fundamental uncertainties remain, however, if left unaccounted process, they compromise appropriateness approaches outcomes. recommend incorporate known birds framework Net Environmental Benefit Analysis (NEBA) POE concept models provided. These recommendations particularly relevant where NEBA becoming more standardized component Additionally, greater investment lab field-based research, field observations through monitoring, required address existing information gap closure.