Mono Lake Could Be Losing Its California Gulls

The report attributed the low survival rate to the scarcity of the brine shrimp essential to the breeding gulls’ diet. That scarcity, in turn, is the product of an unusual stratification of lake waters due to its artificially low levels.

“When gulls are nesting, they really depend on the abundant shrimp,” Miller said. “They basically gobble that up, and then they take it back to the nest and they regurgitate it for the chicks.”

The gulls’ reproductive crash is prompting calls for state water regulators to reconsider measures ordered more than three decades ago to restore Mono Lake’s degraded ecosystems.

In 1994, the state Water Resources Control Board issued a landmark decision that was meant to halt a half-century of excessive water diversions from the eastern Sierra’s Mono Lake and begin the long process of environmental recovery.

Crucially, the order aimed to create the conditions that would allow the lake’s water level to rise by about 17 feet — from 6,375 to 6,392 above sea level — to a point biologists testified would benefit key species.

Recurring droughts and continuing diversions from the lake by the Los Angeles Department of Water and Power have combined to keep Mono well below the target level. Its current surface elevation is 6,383 feet.