Sunjo Claris sits in a boat collecting water samples.
Sunjo Claris collects water samples and measures water quality parameters.

Claris Sunjo Explores Carbon Cycling in Cameroon’s Wouri Estuary to Address Anthropogenic Pollution

  • by David Arias

From Mungo to Wouri to Dibamba, Cameroon’s rivers converge near the urban center of Douala, creating the tropical mangrove habitat known as the Wouri estuary. Immersed in this essential ecosystem for biodiversity, Sunjo Claris, a Ph.D. student in the Department of Earth and Planetary Sciences at UC Davis, is spending her summer investigating carbon cycling—a critical process for preserving the resilience of the estuary.

Due to significant anthropogenic pollution, the Wouri estuary now faces substantial challenges including degraded water quality, disrupted carbon cycling, and impaired the ecosystem’s goods and services. Claris’ research offers valuable insights for water quality monitoring and resource management decision-making.

“I am particularly motivated to carry out this research, as it is not only about my intellectual and professional growth but, more importantly, about giving back to my home country, which I hold dear to my heart,” Claris said.

During her time in the field, Claris actively measures water quality parameters using a multiparameter probe. “I examine parameters including temperature, pH, salinity, electrical conductivity, dissolved oxygen, and total dissolved solids in the water column, while also collecting samples for dissolved inorganic carbon (DIC) and carbon isotope analysis.”

Claris’ research seeks to fill critical knowledge gaps regarding solutes, carbon, and nutrient cycling in tropical mangrove estuaries. The findings from the Wouri estuary could serve as a guide for other estuaries grappling with similar challenges posed by pollution. By applying her models to hydrogeochemical studies in tropical mangrove estuaries globally, Claris hopes to contribute to a broader understanding of these vital environments.

Presently, Claris is a member of the College of Letters and Science Diversity, Equity, and Inclusion Committee and is a Global Affairs Global Education for All Fellow. She is the only graduate student representative serving with the UC Davis Global Affairs Advisory Council. She also works with Geology undergraduates as a Graduate Research and Teaching Assistant.