Pilot Project Tests Olivine Addition to Ocean for Carbon Removal

A field trial conducted by Vesta in Southampton, New York, placed 650 tonnes of crushed olivine on top of 13,500 tonnes of regular beach sand in 2022. Waves carried the olivine offshore, where researchers sampled sediment and organisms out to 160 metres before the addition, immediately after, and again one year later.

Sediment cores showed that overall abundance and diversity of bottom-dwelling species recovered within two months at the olivine site. Only one species, the fringed blood worm, declined in the olivine area. The same species composition shift occurred at the regular-sand site, indicating the change was linked to beach nourishment rather than olivine.

Concentrations of nickel, chromium, cobalt, and manganese in sampled organisms remained low and comparable across all three beach sections. Emilia Jankowska of Hourglass Climate, who led the independent analysis, stated that rapid dilution in the dynamic coastal environment limited accumulation of any dissolving constituents.

Kerry of OceanCare noted that burial-re-exposure cycles may have reduced olivine exposure during the trial, limiting the strength of the no-adverse-effects conclusion. Christopher Pearce of the National Oceanography Centre said further trials are needed to measure different biological responses and rates of CO2 uptake.

Hourglass Climate is now analyzing data from a larger 2024 trial in which Vesta deposited 8,200 tonnes of olivine 450 metres off Duck, North Carolina. Preliminary results indicate species abundance and diversity recovered, while metal accumulation analysis continues.