[A-CG31] Nutrient footprint of primary production in the coastal and marginal seas of East and Southeast Asia

[ACG31-P06] Effect of land use and climate change on coastal waters in Cameroon-Central Africa

*Therese Line Laure Jokam Nenkam¹, Jing ZHANG², Wilson Yetoh Fantong³ (1.Graduate School of Science and Engineering, University of Toyama, 2.Faculty of Science, Academic Assembly, University of Toyama, 3.Institute of Geological and Mining Research, Ministry of Scientific Research and Innovation, Cameroon)

Keywords:Water quality, Nutrients, Trace elements, Coast, Cameroon

Climate change in combination with increased anthropogenic activities affects coastal water systems throughout the world. Therefore, assessing water quality from land will provide information on the impact that land-based anthropogenic activities have on marine ecosystems. This study focuses on the coast of Cameroon, which drains 03 (Coastal, Sanaga, and Benoue) of the 05 (Coastal, Sanaga, Benoue, Congo, and Chad) hydrological basins in Cameroon. Cameroon is part of the Gulf of Guinea, experiences the 2^nd highest annual rainfall of about 11000 mm in the world, is home to nearly 60% of the national industrial complexes and most urban centers, has a population growth of about 15% and urbanization rate is 30% greater than the national average, it represents a melting pot of a continent-coastal-marine (CCM) nexus for holistic management of biodiversities. We used isolated investigations along the coast of Cameroon to evaluate surface and groundwater quality, and nutrient and trace element distribution. The results show the drop in the quantity of rainfall and enrichment of stable environmental isotopes in rainwater over the past 50 years; deterioration of freshwater resources by seawater intrusion and anthropogenic activities; wide spread of industries that discharge a large number of chemicals into the ocean, and degradation of biodiversities. These problems are further aggravated by either the paucity or the total absence of comprehensive data on the CCM nexus. Further investigations are urgently needed to comprehend the recent flux of pollutants into the ocean by giving a complete description of the hydrogeochemical processes of the site and generating data that could enhance the understanding of the CCM nexus.