‘On a razor’s edge’: migratory birds rely on this salt lake – but it’s dying

Lake Abert is a rare and vital habitat for phalaropes and avocets among other wading birds. As the salt lake shrinks, its salinity increases and the invertebrates that the birds feed on cannot survive. It is one of many lakes in the US that have had much of the waters that feed it extracted. Photograph: Tim Giraudier

The water level in Oregon’s remote, salty Lake Abert fell to unusually low levels in July 2013. As it did, the salt concentrations became too high even for the few species adapted to its saline waters. Tiny brine shrimp and alkali flies died en masse. By September, so much water had been lost that the salts precipitated into a shimmering white crust of triangular crystals.

Daily counts of shorebirds had reached 350,000 in July – a higher density than is found even at the Great Salt Lake – but after the lake dried out and remained empty the following summer, bird counts dropped by 90%.