The Status and Distribution of the Freshwater Fishes of Southern California
The fresh and low salinity waters of southern California include the Owens, Mohave, Colorado, and coastal drainages south of Monterey Bay to the Mexican border. The youthful topography presents a strong dichotomy between steep rocky streams abruptly meeting relatively flat deserts or coastal plains. Little or no intermediate, foothill habitat exists. Thirty-eight native freshwater and 23 estuarine fishes have been recorded from this area. In addition, at least 1 00 species have been introduced, with widely varying success. Since the late 1940s and 1950s the native fishes of the Owens, Colorado, and Mohave drainages have been in jeopardy or extirpated in California. At the same time, the lowland fishes in coastal drainages, particularly on the Los Angeles Basin, also disappeared. Upland species of the coastal drainages still remain in a few isolated areas but are so reduced that special protection is needed. Only one estuarine species, Eucyclogobius newberryi, is threatened. Some tropical estuarine species of extreme southern California were last collected 50 to 80 years ago, and are very rare or extirpated here. If the remaining elements of the fish fauna are to survive, immediate action is needed to preserve the remaining habitat and to restore areas within the native range.
Swift, Camm C.; Haglund, Thomas R.; Ruiz, Mario; and Fisher, Robert N.
"The Status and Distribution of the Freshwater Fishes of Southern California,"
Bulletin of the Southern California Academy of Sciences:
Available at: https://scholar.oxy.edu/scas/vol92/iss3/2