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The Forms of Carbon Storage in the Oceans

The world's oceans play a crucial role in the global carbon cycle, serving as a vast reservoir that stores and exchanges carbon with the atmosphere and terrestrial ecosystems. The forms in which carbon is stored in the oceans are diverse and dynamic, encompassing both organic and inorganic compounds, as well as various physical and biological processes that govern their storage and release.

The primary forms of carbon storage in the oceans include dissolved inorganic carbon, dissolved organic carbon, and particulate organic carbon 1. Dissolved inorganic carbon, which includes carbonate, bicarbonate, and carbon dioxide species, is the largest pool of carbon in the oceans, accounting for approximately 38,000 gigatons of carbon 1. This carbon is primarily derived from the dissolution of atmospheric carbon dioxide and the weathering of terrestrial carbonate rocks 2.

Dissolved organic carbon is the second-largest pool of carbon in the oceans, comprising approximately 700 gigatons of carbon 3. This organic carbon is derived from the decomposition of plant and animal matter, as well as from the excretion and release of organic compounds by marine organisms 4. Importantly, a significant fraction of this dissolved organic carbon is considered "refractory," meaning it is resistant to further breakdown and can persist in the ocean for thousands of years 3.

In addition to dissolved forms, carbon is also stored in the oceans as particulate organic carbon, which includes the remains of dead organisms, fecal matter, and other organic particles 2. This particulate organic carbon is an essential component of the "biological pump," the process by which carbon is transported from the surface to the deep ocean through the sinking of these particles 5.

The storage and cycling of carbon in the oceans is a complex and dynamic process, driven by both physical and biological factors. Understanding the different forms of carbon storage in the oceans is crucial for accurately modeling the global carbon cycle and predicting the potential impacts of climate change on marine ecosystems 1 3 5.

Sources​

Relevant reference works​

Sarmiento, J. L. (2006). Ocean biogeochemical dynamics. https://doi.org/10.1515/9781400849079

Hamme, R. C., & Emerson, S. (2022). Chemical oceanography: Element fluxes in the sea. Retrieved from https://www.cambridge.org/highereducation/books/chemical-oceanography/1CB0B55C9B9D6E7D58B4920284F6431B

Footnotes​

  1. Feely, R. A., Sabine, C. L., Takahashi, T., & Wanninkhof, R. (2001). Uptake and storage of carbon dioxide in the ocean: The global CO2 survey. Oceanography, 14(4), 18-32. https://doi.org/10.5670/oceanog.2001.03 ↩ ↩2 ↩3

  2. de Haas, H., van Weering, T. C. E., & de Stigter, H. (2002). Organic carbon in shelf seas: Sinks or sources, processes and products. Continental Shelf Research, 22(5), 691-717. https://doi.org/10.1016/s0278-4343(01)00093-0 ↩ ↩2

  3. Hansell, D. A., & Carlson, C. A. (2013). Localized refractory dissolved organic carbon sinks in the deep ocean. Global Biogeochemical Cycles, 27(3), 705-710. https://doi.org/10.1002/gbc.20067 ↩ ↩2 ↩3

  4. Kieber, D. J., Keene, W. C., Frossard, A. A., Long, M. S., Maben, J. R., Russell, L. M., Kinsey, J., Tyssebotn, I. M. B., Quinn, P. K., & Bates, T. S. (2016). Coupled ocean-atmosphere loss of marine refractory dissolved organic carbon. Geophysical Research Letters, 43(6), 2765-2772. https://doi.org/10.1002/2016gl068273 ↩

  5. Jiao, N., & Zheng, Q. (2011). The microbial carbon pump: From genes to ecosystems. Applied and Environmental Microbiology, 77(21), 7439-7444. https://doi.org/10.1128/aem.05640-11 ↩ ↩2