Global Patterns in Marine Sediment Carbon Stocks

• Main Authors: Trisha B. Atwood, Andrew Witt, Juan Mayorga, Edd Hammill, Enric Sala
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2020-03-01
• Series: Frontiers in Marine Science
• Subjects: blue carbon; soil carbon; carbon storage; climate mitigation; carbon cycle; SOC
• Online Access: https://www.frontiersin.org/article/10.3389/fmars.2020.00165/full

To develop more accurate global carbon (C) budgets and to better inform management of human activities in the ocean, we need high-resolution estimates of marine C stocks. Here we quantify global marine sedimentary C stocks at a 1-km resolution, and find that marine sediments store ∼ 3117 (3006–3209) Pg C in the top 1 m (more than twice that of terrestrial soils). Sediments in abyss/basin zones account for 75% of the global marine sediment C stock, and 52% of that stock is within the 200-mile Exclusive Economic Zones of countries. Currently, only ∼2% of sediment C stocks are located in highly to fully protected areas that prevent the disturbance of the seafloor. Our results show that marine sediments represent a large and globally important C sink. However, the lack of protection for marine C stocks makes them highly vulnerable to human disturbances that can lead to their remineralization to CO2, further aggravating climate change impacts.