Hydrological and ecosystem impacts of in-stream artisanal aggregate and tin mining in central Rwanda

The integrity of freshwaters is vital to maintaining healthy aquatic (and terrestrial) ecosystems. Though humans rely on freshwaters as a key natural resource and these systems support uniquely high levels of biodiversity, they are exceptionally threatened and highly exploited. The extraction of geologic commodities, including critical minerals and aggregate materials (sand, gravel, etc.), often occurs in river channels and/or the waste materials of these activities interact with water courses. Artisanal and small-scale mining is often overlooked in the evaluation of mining’s environmental impact and contribution to sustainable development. Understanding the hydrological and ecological responses to landscape disturbances caused by artisanal in-stream mining is important for the management of aggregate and mineral resources, freshwaters, and freshwater biodiversity. This work presents the case study of the Rusine River in Rwanda, in which both artisanal aggregate and tin mining occur. Primarily relying field data but supported by remote sensing, we present comprehensive data describing the abiotic and biotic components of the freshwater system along the course of the watershed. We explore the localized and system-scale impacts of these mining activities, evaluating the integrity of the watershed and its ecosystem functioning. We compare this system to similar rivers lacking some of the exploitative land uses in the Rusine. This work provides insight into responsible natural resource management in rural Rwanda with global lessons in preserving freshwater ecosystem services.

Presentation Preference: Standard Oral (12 Minutes)

Primary Presenter: Aelis Spiller, McGill University (aelis.spiller@mail.mcgill.ca)

Authors:

Aelis Spiller, McGill University  (aelis.spiller@mail.mcgill.ca)

Placide Habinema, Rwanda Mining Board  (aelis.spiller@mail.mcgill.ca)

Mette Bendixen, McGill University  (mette.bendixen@mcgill.ca)

Lars Lonsmann Iversen, McGill University  (lars.iversen@mcgill.ca)