The endangered Tidewater Goby is currently being split into two distinct species. The new “Southern Tidewater Goby” species description is currently in review for publication. Genetic and morphological data both show that populations in southernmost California are distinct from those in the rest of the state. The range of this southern species is restricted to San Diego and Orange County and has only been found in nine coastal lagoons over the past 30 years. This suggests a high degree of persistent endangerment and the need for increased protection.