California Gull (Larus californicus) feeding in Mono Lake. By stirring the water with its feed, the gull finds fly larvae to eat. Mono Lake is a terminal lake in a basin that has no outlet to the ocean. Because it has no outlet, dissolved salts make the lake very alkaline and salty. Brine Flies (Ephydra hians) are one of only two animals that can tolerate the salty environment. Their larvae live in the water, eating single-celled algae. These flies are an important food source for migratory and nesting birds, including the California Gulls.