Harvesting study reveals limited ecosystem stress

A study by Bryan O’Malley and several co-authors, which was discussed at an industry conference in November of 2023, demonstrated the level of environmental stress to foraminifera from harvesting operations in the CCZ during a harvesting program that ran in the fall of 2022. Link

The study examined foraminifera (“forams”) because these small, single-celled creatures are considered to be excellent bioindicators of ecosystem stressors and the ISA recommends that they be studied to monitor stress from harvesting. Forams are good proxies for stressors because they are highly sensitive to small environmental changes and because they are found in great abundance in the benthic environment.

O’Malley’s work indicates a 20% decline in biodiversity in the path of the harvester and a 0% decline in biodiversity for foraminifera outside the tracks, in the plume zone.  The study showed a 50% reduction in biodensity in the tracks and a 0% reduction in biodensity in the plume zone. 

This data is consistent with what we have seen on long-term environmental impact assessments going back 45 years.  It’s important to note that the biodiversity in long-term studies has shown evidence of a return to a level that has sometimes even exceeded baseline.  We think that’s because harvesting adds variation in the topography, and more variation usually translates to greater diversity.  By comparison, terrestrial battery mineral mines in SE Asia and Africa will typically reduce biodiversity and biodensity by 100% in the mine footprint and lead to an array of indirect impacts over a much wider area.    

The data on impacts is found on slide 43 in the report.