Journal
PHOTOCHEMISTRY AND PHOTOBIOLOGY
Volume 98, Issue 5, Pages 1025-1042Publisher
WILEY
DOI: 10.1111/php.13597
Keywords
-
Categories
Funding
- Transnational Access Programme of the AQUACOSM project - European Union's Horizon 2020 Research and Innovation Programme [731065]
- Unite States National Science Foundation chemical oceanography [1635618]
- Directorate For Geosciences
- Division Of Ocean Sciences [1635618] Funding Source: National Science Foundation
Ask authors/readers for more resources
Humic substances, a component of terrestrial dissolved organic matter, play a significant role in coastal waters by contributing to dissolved organic matter and chromophoric DOM. Photodegradation can rapidly remove added tDOM, while nutrient additions do not significantly influence the effects of humic substances on CDOM optical properties but induce changes in DOM removal.
Humic substances, a component of terrestrial dissolved organic matter (tDOM), contribute to dissolved organic matter (DOM) and chromophoric DOM (CDOM) in coastal waters, and have significant impacts on biogeochemistry. There are concerns in recent years over browning effects in surface waters due to increasing tDOM inputs, and their negative impacts on aquatic ecosystems, but relatively little work has been published on estuaries and coastal waters. Photodegradation could be a significant sink for tDOM in coastal environments, but the rates and efficiencies are poorly constrained. We conducted large-scale DOM photodegradation experiments in mesocosms amended with humic substances and nutrients in the Gulf of Finland to investigate the potential of photochemistry to remove added tDOM and the interactions of DOM photochemistry with eutrophication. The added tDOM was photodegraded rapidly, as CDOM absorption decreased and spectral slopes increased with increasing photons absorbed in laboratory experiments. The in situ DOM optical properties became similar among the control, humic- and humic+nutrients-amended mesocosm samples toward the end of the amendment experiment, indicating degradation of the excess CDOM/DOM through processes including photodegradation. Nutrient additions did not significantly influence the effects of added humic substances on CDOM optical property changes, but induced changes in DOM removal.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available