A key consideration for the implementation of the Agreement Under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ Agreement) is managing the relationship between overlapping international frameworks. For environmental impact assessment (EIA), this objective finds expression in an exception to the general obligation to conduct an EIA where the activity has been assessed in accordance with the requirements of another legal instrument that is equivalent to the EIA provisions of the BBNJ Agreement. The equivalence exception is ambiguous in the sense that equivalence is a matter of degree. This article proposes a purposive approach to assessing equivalence, which is applied to four existing EIA processes that have potential to overlap with the BBNJ Agreement EIA process.
