The worst drought on record has lowered the water level of the rivers in the Amazon basin to historic lows, in some cases drying up riverbeds that were previously navigable waterways.

The Solimoes, one of the main tributaries of the mighty Amazon River whose waters originate in the Peruvian Andes, has fallen to its lowest level on record in Tabatinga, the Brazilian town on the border with Colombia.

Downriver in Tefé, a branch of the Solimoes has dried up completely, as seen by Reuters reporters who flew over the river on Tuesday.

The nearby Lake Tefé, where more than 200 freshwater dolphins died in last year’s drought, has also dried up, depriving the endangered pink mammals of a favorite habitat.