SACRAMENTO, Calif. (KGO) -- The California drought may have pushed a tiny fish species to the point of no return.In a recent survey, researchers found only six Delta smelt in the Sacramento-San Joaquin Delta when there should be thousands of them.The smelt population has been declining for 30 years, but a biologist at UC Davis says it's now on the verge of extinction.To protect the smelt, state water officials must shut down the massive pumps that send water to farmers in the Central Valley.If the smelt is declared extinct, it could change how the state's water supply is managed.