Cooperative Agreement for affiliated Partner with the Californian Cooperative Ecosystem Studies Unit

The USGS is offering a funding opportunity to a CESU partner for research in carbon cycling in seabed mineral environments. Seabed minerals may contain economically significant concentrations of valuable metals and rare earth elements which are essential to transportation, technological products, and defense and national security applications (i.e., critical minerals; Energy Act, 2020;

U.S. Geological Survey, 2025; Hein et al., 2013, 2020). Of particular interest are manganese nodule fields throughout the abyssal Pacific Ocean, including in some U.S. EEZs, which have garnered attention over recent decades as potential areas for deep-sea mineral mining.

Still, much more research is needed to understand the environmental settings where these minerals occur, how they form, and potential implications of extraction. This is crucial information for EO 14241 , 14285 , 14272 and SO 3417 . Carbon cycling is a key component of baseline environmental conditions within offshore resource systems.

Sedimentary organic carbon is the primary food source at the base of deep sea food webs, and disturbance from marine mining could significantly alter carbon cycles and decrease benthic microbial and faunal activity. Benthic and midwater plumes generated by marine mining activities may further impact carbon cycling and biologic activity.

From a mineral resource assessment perspective, sedimentary organic carbon plays a key role in manganese nodule formation and metal enrichment, though the carbon content, composition, and mechanisms to influence nodule formation remain unknown. The role of organic carbon in metal preservation for sediment covered seafloor massive sulfide systems is also a frontier science question.

Sedimentary organic carbon can also be altered to oil or gas by high temperatures and/or pressures below the seafloor, sometimes co-occurring with seabed minerals at hydrothermal systems. Understanding these processes informs OCSLA 1953 & 1978 , and SO 3418 . Despite this importance, carbon cycling in marine mineral systems has received little attention, and fundamental science questions

remain regarding how organic carbon cycling varies globally among nodule fields with differing sediment organic carbon content.