ern are the main food of
<br />Mures confine the trout
<br />water with the trout is
<br />~tomdwelling habits, is
<br />entirely maintained by
<br />p Pine Creek, the lake's
<br />the flows of the creek
<br />~f trout eggs and fry in
<br />In California, each with
<br />~, and the Owens River.
<br />it recently.
<br />Mojave tui chub, now
<br />introduced warmwater
<br />rings that drain into it,
<br />Creek is home to Salt
<br />alt into which the creek
<br />l all its subspecies that
<br />tce. The pupfish live in
<br />we in the outflows of a
<br />2pfish, Owens sucker,
<br />'uh fauna of the three
<br />y disrupted to supply
<br />tdy the native fishes in
<br />at. Dace seem to have
<br />ie lower reaches, while
<br />Quito larvae and other
<br />law-elevation sections
<br />vertebrates, and the tui
<br />tes.
<br />which supports a good
<br />It also contains large
<br />o be hybrids between
<br />Lake Basin, originally
<br />qty of fishes have been
<br />h•ahitude lakes in the
<br />of species native to a
<br />-stern United States),
<br />rystem), golden trout
<br />ECOLOGY 43
<br />(upper Kern River), tui chubs (Lahontan system), Owens sucker (Owens system), and
<br />threespine stickleback (coastal California).
<br />COLORADO RIVER
<br />The short section of the Colorado River that borders California bears little
<br />resemblance to the great river of a hundred years ago. The flows have been reduced
<br />and confined behind dams, forming large reservoirs like Lake Havasu. The formerly
<br />heavy silt load has been reduced, the reservoirs acting as settling basins, but in its place
<br />are salts, fertilizers, and other products of irrigation agriculture. Not surprisingly, the
<br />fish fauna has changed drastically, more so than in any other river system in California.
<br />The original fauna was simple, since the California portion of the river was an
<br />ecologically uniform deep, muddy, sluggish channel with fluctuating flows and no
<br />large tributary streams. In the main channel were bottom-feeding humpback sucker
<br />and omnivorous bonytail, both species with bizarre body shapes adapted for moving
<br />about in strong currents. Preying on these two species, as well as on their own young,
<br />were giant Colorado squawfish. Desert pupfish may have been found in the shallow
<br />marshes on the river's edge. The only other fishes present were rare stragglers from
<br />upstream, such as speckled dace and flannelmouth sucker, and euryhaline wanderers
<br />from the Gulf of California, such as machete and spotted sleeper. Mullet, although
<br />abundant in the saline lower river now, were apparently originally uncommon migrants
<br />from the gulf.
<br />Today, with the exception of mullet, the native fishes are extinct or rare in the
<br />California portion of the river. The river and reservoirs contain instead a conglomera-
<br />tion of introduced species: carp, red shiner, threadfin shad, several species of catfish,
<br />largemouth bass, striped bass, bluegill, green sunfish, mosquitofish, Mozambique
<br />mouthbrooder, etc. Obviously this is an unstable, artificial assemblage of fishes that
<br />will keep changing as long as man keeps changing the nature of the river and
<br />introducing new species into it.
<br />SALTON SEA
<br />The Salton Sea is the largest inland body of water within California, with a surface
<br />area of about 548 km2. It fills the bottom of the Salton sink in the Imperial Valley, at
<br />an elevation of 71 m below sea level. The sea is shallow (maximum depth, 12 m),
<br />warm (summer tempeatures, 26 to 33°C; winter temperatures, 10 to 17°C), and saline
<br />(1971 salinity, 37 ppt). Although overflows from the Colorado River have filled the
<br />sink many times in the past, the bodies of water so created have usually dried up in a
<br />few years. The present sea was created in the summer of 1905 when, during a flood,
<br />the entire Colorado River started flowing through and enlarging the Alamo Channel, a
<br />canal dug to bring irrigation water to the Imperial Valley. The river wntinued to
<br />empty into the sink until February, 1907, when its flow was finally diverted back into
<br />its former channel through a massive earth-moving effort. The level of the sea is
<br />presently maintained through the inflow of irrigation water from the Imperial Valley.
<br />Unfortunately, the high salt content of the irrigation water combined with rapid
<br />
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