Photomineralization of organic carbon in a eutrophic, semiarid estuary

The effect of photomineralization on the carbon cycle in a eutrophic, semiarid estuary (Baffin Bay, Texas) was investigated using closed‐system incubations. Photochemical production rate of dissolved inorganic carbon ranged from 0.16 to 0.68 μM hr−1, with a daily removal of 0.3∼1.5% of the standing...

Full description

Bibliographic Details
Published in:Limnology and Oceanography Letters
Main Authors: Wang, Hongjie, Hu, Xinping, Wetz, Michael S., Hayes, Kenneth C., Lu, Kaijun
Format: Article in Journal/Newspaper
Language:unknown
Published: 2020
Subjects:
Online Access:https://hdl.handle.net/1969.6/89412
https://doi.org/10.1002/lol2.10146
Description
Summary:The effect of photomineralization on the carbon cycle in a eutrophic, semiarid estuary (Baffin Bay, Texas) was investigated using closed‐system incubations. Photochemical production rate of dissolved inorganic carbon ranged from 0.16 to 0.68 μM hr−1, with a daily removal of 0.3∼1.5% of the standing stock of dissolved organic carbon (DOC). The photomineralization rate was negatively correlated with chlorophyll a concentration, suggesting that plankton‐derived DOC was less photoreactive to solar radiation. The stable carbon isotope composition (δ13C∼ −18.6‰) of degraded DOC, as calculated using the DIC “Keeling” plot, further indicated high photochemical lability of 13C‐enriched DOC in this semiarid environment. Our finding showed that photomineralization of 13C‐enriched DOC is an important component of carbon cycle in this system, and this process does not necessarily remove 13C‐depleted organic carbon as observed in other coastal systems.