Collaborative Research: Wildlife subsidies interact with discharge to influence ecosystem function of a large African river

Cary Institute Of Ecosystem Studies, Inc., Millbrook NY

Investigators

Abstract

Animal migrations are some of the most remarkable spectacles of nature and can result in significant engineering of ecological processes. For example, migrating animals have the potential to move large amounts of carbon, nitrogen, and other important nutrients among ecosystems. The Mara River in East Africa supports the largest remaining overland migration in the world: 1.5 million wildebeest and over 4,000 hippopotami. This project will use small-scale and whole-stream experiments, river sampling and theoretical models to test how nutrient inputs into the Mara River by wildebeest and hippopotami interact with river discharge to influence ecosystem processes such as primary production, nutrient cycling, and whole-ecosystem metabolism. The Mara River is one of the few remaining unregulated rivers heavily influenced by large wildlife populations, and provides a unique opportunity for research. Findings will improve understanding of ecosystems where large wildlife play an important role, and provide a baseline for comparison with systems where wildlife have disappeared or been replaced by humans and domesticated animals. This research will have relevance to regional concerns relating to both wildlife and water quality. The Mara River is critical to the Serengeti Mara ecosystem and provides water for nearly one million rural poor. Declining water quality has been linked to outbreaks of typhoid and cholera, and eutrophication of Lake Victoria. In addition, wildebeest migration and mass drowning events are of local concern to managers in the Maasai Mara National Park. Research will also address human inputs into the river, which may inform decision makers about how more effective sewage treatment could benefit the region. The project will train undergraduate students, graduate students, and a postdoc from the USA, and graduate students from around East Africa. Partnerships with the National Geographic Society and World Wildlife Fund (WWF) will distribute research results through print, video and web-based initiatives. The WWF partnership will use real-time monitoring data from the Mara, photos from live camera traps, and blog updates to disseminate findings to stakeholders, resource managers, and the public.