The degradation of lake La Pastora as an example of Amazon freshwater ecosystems facing gold mining

As part of a research trip outside protected areas, the giant otter team recently visited lake La Pastora, deep inside the Madre de Dios gold mining corridor. The views were sad. The banks are now completely degraded. We counted at least five mining dredges and the lake is open to the river through a channel, making it easy to transport heavier machinery.

Until recently, the lake was protected by the native community of Tres Islas, who has the concession for the land. Despite serious extractive activities in this area in the last four decades, community members were able to keep out miners and fishers who had their sights on the lake's resources.

During our previous visit in the 2021 dry season, the lake had no water, only roots and logs, the remains of what used to be the aquatic vegetation. Since then, things have changed, but not necessarily for the the best.

The water has returned, but this also means that it's easier to transport heavy materials, such as engines, pumps and petrol barrells inside. The extraction that comes with them promotes the destruction of the lake.

Between 2017 and 2019, we studied the giant otters, fish and birds in this lake. We regularly found a family group of nine otters, which we were able to follow. On the banks, freshwater birds like least grebes, kingfishers and herons were quite abundant.

Knowing this area from regular visits, it feels that this lake was one of the last strongholds of relatively intact freshwater habitat. The current situation underscores the urgency of protecting this type of habitat in the face of extractive activities that are only increasing as Peru's political and economic situation deteriorates.