EGU22-4789
https://doi.org/10.5194/egusphere-egu22-4789
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

The role of the Belize River in localised coastal ocean acidification. 

Sarah Cryer1,2, Stacey Felgate2, Peter Brown2, Filipa Carvalho2, James Strong2, Terry Wood2, Gilbert Andrews3, Samir Rosado3, Arlene Young3, Millie Goddard-Dwyer2, Socratis Loucaides2, Richard Sanders2,4, and Claire Evans2
Sarah Cryer et al.
  • 1University of Southampton, Ocean and Earth Science, United Kingdom of Great Britain – England, Scotland, Wales (s.e.cryer@soton.ac.uk)
  • 2National Oceanography Centre Southampton, UK
  • 3Coastal Zone Marine Authority and Institute, Belize
  • 4Norwegian Research Centre (NORCE)

The Mesoamerican Barrier Reef, the second largest barrier reef in the world, is vitally important to the ecology and economy of Belize and neighbouring countries. Coral reefs are inherently vulnerable to ocean acidification and those exposed to significant riverine input may be under enhanced threat. In tropical rivers pCO2 levels may be linked to land use in their catchment, with conversion of pristine forest to agricultural land potentially enhancing carbon flux to the coastal ocean. We investigated the effect the Belize River may have on the carbonate chemistry of surrounding coastal ocean, applying a multidisciplinary methodology. Water samples were collected and measured for: total alkalinity; dissolved inorganic carbon (DIC); and δ13CDIC; and were complemented by pH and pCO2 data acquired from sensors mounted on an autonomous surface vehicle. Samples were collected from the source of the Belize river to the mouth and out past the barrier reef.  pCO2 measuring >1000-µatm at the mouth of the Belize River suggests local high levels of respiration and low pH water being discharged into the coastal ocean. δ13CDIC samples were taken to identify terrestrial DIC signatures and used in combination with sensor data to identify potential controls on coastal pH. There was a distinct difference in δ13CDIC along the river with a range of 27 ‰ to - 13‰, while coastal δ13CDIC was heavier with a range of  -11.5‰ to 1.5 ‰. These results demonstrate the complexity of processes that control coastal ocean acidification, which has implications for coastal economies that are heavily dependent on healthy coral reefs as a resource.

How to cite: Cryer, S., Felgate, S., Brown, P., Carvalho, F., Strong, J., Wood, T., Andrews, G., Rosado, S., Young, A., Goddard-Dwyer, M., Loucaides, S., Sanders, R., and Evans, C.: The role of the Belize River in localised coastal ocean acidification. , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4789, https://doi.org/10.5194/egusphere-egu22-4789, 2022.

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