The Status and Distribution of the Freshwater Fishes of Southern California

Abstract

The fresh and low salinity waters of southern California include the <br /><br />Owens, Mohave, Colorado, and coastal drainages south of Monterey Bay to the <br /><br />Mexican border. The youthful topography presents a strong dichotomy between <br /><br />steep rocky streams abruptly meeting relatively flat deserts or coastal plains. Little <br /><br />or no intermediate, foothill habitat exists. Thirty-eight native freshwater and 23 <br /><br />estuarine fishes have been recorded from this area. In addition, at least 1 00 species <br /><br />have been introduced, with widely varying success. Since the late 1940s and 1950s <br /><br />the native fishes of the Owens, Colorado, and Mohave drainages have been in <br /><br />jeopardy or extirpated in California. At the same time, the lowland fishes in coastal <br /><br />drainages, particularly on the Los Angeles Basin, also disappeared. Upland species <br /><br />of the coastal drainages still remain in a few isolated areas but are so reduced that <br /><br />special protection is needed. Only one estuarine species, Eucyclogobius newberryi, <br /><br />is threatened. Some tropical estuarine species of extreme southern California were <br /><br />last collected 50 to 80 years ago, and are very rare or extirpated here. If the <br /><br />remaining elements of the fish fauna are to survive, immediate action is needed <br /><br />to preserve the remaining habitat and to restore areas within the native range.