Exclusive Economic Volumes: Enriching the palette of tools for Marine Spatial Planning

UNCLOS introduced Exclusive Economic Zones (EEZ) as an instrument for the management of marine areas assigned to the jurisdiction of national States and Sovereignties. EEZ define spatial extents at surface level, without consideration of the shape of the sea bottom or of the height of the water column. In our contribution we explore volume as a new tool for marine planning. We first calculate the volume of water corresponding to each State's current EEZ. We compare the ranking of countries based on EEZ surface with the ranking based on the corresponding volume, and we analyze the movements in the respective rankings. In order to define volumes we then propose a parameter (cross-sectional area) that is analogous to the distance from baseline used for defining EEZ's surfaces,, we propose a constant value for the area of A that is analogous to the 200 nautical miles constant used for calculating EEZ's surfaces. Using this concept, we show the differential impact of local bathimetries on the volumes of water that could fall under national jurisdictions. These volumes differ in general from those currently underlying EEZ. We eventually propose the new precisely defined notion of Exclusive Economic Volumes (EEV) and we draw the surface boundaries of the resulting managed spaces according to two alternate methods: actual local bathimetry and average bathimetry.

As with land territory and EEZ, Exclusive Economic Volume is a rough, prima facie indicator of the wealth of a nation and of the scope of its stewardship on the biological riches inhabiting it. Its calculation highlights geographic and historical imbalances, as well as challenges for biodiversity protection. Decoupling volume from surface in the spatial analysis of the ocean shows other aspects of those imbalances, and hints as ways to correct them and to fine-tune the instruments for addressing protection challenges.