# Weddell Sea study: dissolved organic carbon stays stable despite plankton blooms

- Published: 2026-11-14 12:32 UTC
- Section: Planet › Ocean & water
- Tags: Weddell Sea, dissolved organic carbon, Southern Ocean carbon cycle, Antarctic continental shelf, plankton blooms, Weddell Sea Deep Water, Antarctica InSync, Nature Communications
- URL: https://realtech.media/news/rt-b5ccd6b275c07ee194701ead_weddell_sea_study/

**Samples from the southern Weddell Sea show little change in dissolved organic carbon, which bears on the Southern Ocean's role in the carbon cycle.**

![Weddell Sea study: dissolved organic carbon stays stable despite plankton blooms](https://realtech.media/media/2026/11/0a7d63e18ccfe49c.webp)
*futurezone.de*

A study published in Nature Communications examined water samples from the southern Weddell Sea, off Antarctica. According to the report by futurezone.de, even intense biological processes and changing environmental conditions barely alter the amount and molecular composition of dissolved organic carbon there [1]. The researchers used modern analytical methods to determine both the composition and the age of the carbon contained in the water [1]. The finding may help clarify the role of the Southern Ocean in the global carbon cycle.

## Plankton blooms leave little fresh carbon

Particularly surprising was that, despite pronounced plankton blooms, hardly any traces of freshly produced organic matter could be detected in the sinking water [1]. One explanation is the long residence time of water masses on the continental shelf. There, microorganisms have between six and twelve years to break down readily degradable organic compounds before the water reaches the deep sea [1].

## Limits of the result

The results indicate that the dissolved carbon reservoir in Antarctica is comparatively resilient to certain biological changes. Ongoing warming might therefore affect this particular part of the carbon cycle less strongly than expected, at least initially [1]. This stability does not automatically apply to other forms of carbon, such as particles that sink to the seafloor or dissolved inorganic carbon [1].

Further studies are to determine how different carbon reservoirs develop under altered conditions, since rising temperatures and the retreat of sea ice can substantially change marine ecosystems and their material cycles. International research projects such as Antarctica InSync are meant to help capture these processes more precisely. The underlying paper is titled "Conserved molecular properties of dissolved organic matter during Weddell Sea Deep Water formation" (Nature Communications, 2026).

## Sources

1. [futurezone.de](https://www.futurezone.de/science/article763913/antarktis-forscher-machen-ueberraschende-entdeckung-im-meer.html)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-b5ccd6b275c07ee194701ead_weddell_sea_study/