Modeling the Pelagic Food Web in an African Great Lake: The Effects of Climate Change and Management on Lake Tanganyika's Fisheries

Abstract:

Lake Tanganyika is one of the world’s largest and oldest lakes, leading to high fish biodiversity over a long evolutionary history. Bordered by Burundi, the Democratic Republic of the Congo, Tanzania, and Zambia, the Lake Tanganyika basin is home to over 10 million people and the population continues to grow rapidly. The lake provides essential services to the nearby communities, including clean water, food, and economic opportunities. Historically, Lake Tanganyika had a highly productive fishery; recently, fishery yields have decreased, likely a consequence of overfishing and climate change. To better understand the factors contributing to fisheries decline, we built an Ecopath/Ecosim food web model for Lake Tanganyika’s pelagic ecosystem which explicitly incorporates climate as a driver of primary productivity. We then estimate potential protein gaps now and in the future under different climate change scenarios and explore the potential impacts of various management strategies on fisheries yields. Although tailored to Lake Tanganyika, our methodology has broad applicability across systems (especially in the African Great Lakes region), providing opportunities to modify our models to reflect other systems globally. This project supports climate change planning and adaptation strategies, trying to optimize the long-term co-benefits for people and nature.