Case Studies
Clarion-Clipperton Zone (CCZ) – Environmental assessment and protection in mineral-rich seabed areas beyond national jurisdiction
By Mary Collins, IUCN WCPA Connectivity Conservation Specialist Group’s Marine Connectivity Working Group (MCWG) Graduate Associate, hosted by the Center for Large Landscape Conservation
Context and challenge
The Clarion-Clipperton Zone (CCZ) is an abyssal plain that spans 4.5 million square kilometers (1.7 million square miles) across the central Pacific Ocean reaching depths of ~4,000 – 5,500 meters (12,000 – 18,000 feet) between Hawaii and Mexico. This area, the width of the continental United States, is punctuated by seamounts and small potato-sized polymetallic nodes that protrude from the muddy bottom (figure 1). The nodes host a vast diversity of marine life, as they represent one of the only hard substrate for species to anchor onto in the vast expanse. (Pew Charitable Trusts).
Figure 1. An image of a newly-discovered sea anemone–like cnidarian trailing 2-meter tentacles is captured by the ABYSSLINE Project, drifting 4,100 meters (13451 feet) deep among metal-rich nodules in the CCZ (NOAA).
These potato-sized polymetallic nodules contain nickel, manganese, copper, zinc, cobalt; metals that are becoming increasingly important for modern manufacturing and used for making electronics like rechargeable batteries, touch screens, and much more (NOAA). Extractive activities, thus, are rapidly expanding into deep sea environments where the metals and technologies to extract are available. The International Seabed Authority (ISA) is responsible for mining permitting and habitat protection in areas beyond national jurisdiction, like the CCZ. To date, The ISA has granted 18 deep-sea mining contracts for the CCZ, with allotted exploration areas covering approximately 1 million square kilometers (400,000 square miles) (figure 2). Mining activities would include scraping the seafloor for polymetallic nodule collection, removing the valuable habitat substrate that many species rely on and potentially creating sediment plumes in the removal process, altering the environment (NOAA). Concern among many marine scientists highlights the potential impacts of disturbing the seabed through extraction (Pew Charitable Trusts).
A large risk these mining activities pose is that we may not understand all of the environmental impacts of mining on the environment until it is too late, as there is little known about the environment and the species that live in the deep. One study shockingly showed that experimental dredge sites displayed little to no organism recovery decades after the site was disturbed. Furthermore, it is estimated that 90 per cent of total marine species are yet to be described, many existing in deep sea environments like the CCZ. Marine scientists are just on the forefront of understanding deep sea species and environmental function, and little remains known about how far species range, how populations are connected, and the potential impacts of nodule removal and spreading sediment plumes (Pew Charitable Trusts; McQuaid et al. 2020).
Figure 2. The Clarion-Clipper Zone, with different country's mining claims in colored blocks and the areas of particular environmental interest (APEI) in green lines (International Seabed Authority).
Approach
Environmental impact assessments are critical tools in aiding effective management, especially when there is uncertainty involved in the proposed activity. The ISA and international research partners conducted an environmental impact assessment to better understand species taxonomy, biogeography, and connectivity parameters across a range of scales in the CCZ. Among these parameters, connectivity was particularly important, as it determines ecosystem resilience to disturbance. Since information in the CCZ was limited, connectivity studies for gene flow and habitat patch diversity were critical tools for informing effective management where other parameters were more difficult to measure (Bribiesca-Contreras et al. 2021). Findings from the environmental impact assessment informed the creation of a CCZ Environmental Management Plan.
As a result of the assessment and research, the ISA designated nine sites as Areas of Particular Environmental Interest (APEIs), protected from all mining activities (figure 2). These APEIs were designated in locations surrounding the allotted exploration license areas and each covers ~160,000 square kilometers (61,775 square miles). A key consideration that was used in preserving these areas was diverse habitat representation. Each site was strategically chosen to protect the same habitat type that would potentially be mined. Variations in habitat representation were determined by variations in nodule abundances, food availability, and seafloor topography (including the presence of seamounts) (Pew Charitable Trusts).
Results
The CCZ Environmental Management Plan established no-mining APIs in at least one of every nine known subregions that differ in productivity, depth, and biology, to protect a range of deep sea habitats and biodiversity. This is a prime example of where habitat representation, a component of connectivity conservation, is considered as a key determinant of protection design.
Yet, as mining activities progress, the effectiveness of these APEIs will depend on the degree to which APEI community compositions and functions represent that of mining contract areas and whether, given mining disturbances, regional connectivity persists (Bribiesca-Contreras et al. 2021). Habitat classification and genetic connectivity studies support marine spatial planning and inform decision-making processes in such little-understood deep sea areas, however there remain gaps in knowledge. A growing consensus among scientists encourages the ISA to prohibit seabed mining in at least one-third of the CCZ, with stringent rules where mining is permitted (The Pew Charitable Trusts).
References
Bribiesca-Contreras, G., et al. 2021. Biogeography and Connectivity Across Habitat Types and Geographical Scales in Pacific Abyssal Scavenging Amphipods. Frontiers in Marine Science. https://doi.org/10.3389/fmars.2021.705237.
McQuaid, K.A., et al. 2020. Using Habitat Classification to Assess Representativity of a Protected Area Network in a Large, Data-Poor Area Targeted for Deep-Sea Mining. Frontiers in Marine Science. https://doi.org/10.3389/fmars.2020.558860.
NOAA Ocean Exploration. Deep-sea Mining Interests in the Clarion-Clipperton Zone. https://oceanexplorer.noaa.gov/.
The Pew Charitable Trusts. 2017. The Clarion-Clipperton Zone; Valuable minerals and many unusual species can be found on the eastern Pacific Ocean seafloor. https://www.pewtrusts.org/-/media/assets/2017/12/sea_the_clarion_clipperton_zone.pdf.