Lake Tanganyika houses the most species diversity among the African Great Lakes. Its fishery is dominated by six endemic pelagic species, including four Lates spp., three of which are threatened (Figure 1). However, fishing pressure and climate change are causing a decline in the abundance of these species, consequently threatening their persistence. How these populations are responding to fishing pressure and climate change remains unclear. Coalescent-based genomic tools and fossil data can provide insights into recent demographic histories of these pelagic populations, highlighting evolutionary trends at community and genomic levels in response to fishing pressure and climate change. The current research will evaluate these dynamics using modern genomics and fossil data.
Both climate change and/or fishing pressure are predicted to result in low genetic diversity (π) and low effective population size (Ne) as signatures of declining populations as contrasted with high π and Ne for stable or expanding populations (Figure 2). However, similar π and Ne trends among species will indicate shared environmental factors shaping their evolution, in contrast, different trends will indicate the effect of each species’ genetic background termed idiosyncratic epistasis. Finally, declining fossil abundance will reflect evolutionary change in past community assemblages due to climate change.
Findings will support the formulation of evidence-based policies for the sustainable management of the Lake Tanganyika ecosystem, as well as the broader African Great Lakes and other freshwater ecosystems, in the face of climate change and increasing human impact. Finally, detected genomic signatures of adaptation will inform national, regional, continental, and global aquaculture strategies to meet the future demand for fish protein.