Building Resilience of Lake Bosumtwi to Climate Change (RELAB)

Project summary

Climate change is altering lake ecosystem functions and affecting livelihoods of rural communities dependent on the ecological services of climate-sensitive waterbodies. Anthropogenic pressures may undermine ecosystem resilience and amplify human vulnerability to climate change. At Lake Bosumtwi, climate change has altered the lake’s limnology, resulting in fish decline. Sustainability of the watershed and fish resources is threatened by climate and anthropogenic stressors whose individual and synergistic effects on ecosystem function are unknown. New livelihoods emerging from adaptations to poor fish harvest are altering land use patterns within the watershed with unknown implications for lake health and its ability to rebound from climate impacts and anthropogenic pressures. Our project will resolve the complex interactions at the ecosystem and watershed scale and investigate the dynamics within the socioecological system. This information will be used for policy and management of the Bosumtwi watershed. With high resolution monitoring of lake physics, biogeochemistry, primary production, fisheries, land use changes, sedimentation and livelihood adaptive mechanisms, we aim to collect the most comprehensive dataset in West Africa. These data will be used to develop models that incorporate climate, lake, fisheries and land-use variability to predict the effect of climate and human activities on ecosystem function and fisheries. Our project will harness Ghanaian, Danish and German expertise to interpret complex climate-lake-watershed interactions with novel application of models. Research results will be disseminated to stakeholders through several mechanisms including hands-on workshops coinciding with the project annual meetings. The long-term goal of the project is to build ecosystem resilience and reduce vulnerability by promoting sustainable fisheries, livelihoods and watershed management through the training of scientists, students and managers.

Outputs

Midterm report:
Lake Bosumtwi is the only natural lake in Ghana, and is recognized by UNESCO as a World Heritage Site for its natural and cultural significance. Climate warming is influencing the lake, which may undermine its ecological and socioeconomical significance. RELAB investigates how the lake, and the associated livelihoods, responds to climate change. As one of the key outcomes of RELAB, a comprehensive two-year field campaign has now been completed, covering both traditional chemistry indicators, but also biology in terms of phytoplankton, zooplankton and fish. Combining the new data with historical records, RELAB is now analyzing the trajectory of the lake, and how it is responding to changes in climate. A state-of-the-art ecosystem model has also been set up, and adapted to the lake based on the collected data. The model will be used to project and assess how the lake may respond to future climate changes.