Abstract
This study focuses on analyzing the annual cycles of air-sea CO2 fluxes and the
eutrophication state in Bou-Ismail Bay, Algeria. Through meticulous collection of physicochemical data, including temperature, salinity, pH, dissolved oxygen, total alkalinity,
chlorophyll, and phytoplankton, this research makes a significant contribution to the
understanding of these phenomena.
The main conclusions of this study are as follows:
- During winter, Bou-Ismail Bay acts as a source of CO2 to the atmosphere, characterized by
significant vertical mixing and oversaturation of oxygen throughout the water column.
- In spring, the intensification of photosynthetic activity leads to an increase in water pH and a
decrease in partial pressure of CO2, thus transforming the region into a CO2 sink for the
atmosphere.
- In summer, despite reduced photosynthetic activity, the bay continues to serve as a CO2
sink, featuring thermal stratification of the water column and slightly undersaturated oxygen
levels in the deeper layers.
- Despite the discharge of untreated domestic wastewater into the bay, no eutrophication was
observed during the study period, these findings are of paramount importance in the
environmental context of Algeria and contribute to a better understanding of biogeochemical
cycles and potential impacts of climate change on this coastal region.