Influences on nutrient cycling within Lake Tanganyika, eastern Africa, during the Common Era inferred from sedimentary geochemistry

Lake Tanganyika, the world’s longest and second deepest lake, is shared by Burundi, Tanzania, Zambia, and the Democratic Republic of the Congo. Located in a region where resources can be limited, the lake and its fishery serve as vital sources of protein, freshwater, and economic development for 12 million people living within its catchment. Unfortunately, over the past several decades, the lake has experienced declines in biodiversity, natural habitat, and economic utility, most clearly evident in reduced fish catch rates. The causes of this decline are complex and still debated, but they may include changing fishing practices, climatic variability, and land use. This project seeks to uncover the historic drivers of nutrient cycling in the lake to determine which factors ultimately govern its fishery productivity. In this study, we use oxygen isotopes in phosphate and isotopes of carbon and nitrogen from sediment cores covering the past 2,000 years to explore how internal lake processes have been influenced by human activity and environmental processes. The findings aim to inform sustainable fishery management strategies.