California
The California golden trout (Oncorhynchus aguabonita or Oncorhynchus mykiss aguabonita), is a species of trout native to California. The golden trout is normally found in the Golden Trout Creek (tributary to the Kern River), Volcano Creek (tributary to Golden Trout Creek), and the South Fork Kern River. The Golden trout is the official freshwater state fish of California since 1947.
The California golden trout is closely related to two rainbow trout subspecies. The Little Kern golden trout (O. m. whitei), found in the Little Kern River basin, and the Kern River rainbow trout (O. m. gilberti), found in the Kern River system. Together, these three trout form what is sometimes referred to as the "golden trout complex".
The golden trout has golden flanks with red, horizontal bands along the lateral lines on each side and about 10 dark, vertical, oval marks (called "parr marks") on each side. Dorsal, lateral and anal fins have white leading edges. In their native habitat, adults range from 6 to 12 inches (15 to 30 cm) long. Fish over 12 inches (30 cm) are considered large. Golden trout that have been transplanted to lakes have been recorded up to 11 pounds (5.0 kg).
The golden trout should be distinguished from the similarly named golden rainbow trout, also known as the palomino trout. The golden rainbow is a color variant of the rainbow trout.
The golden trout is commonly found at elevations from 6,890 feet (2,100 m) to 10,000 feet (3,000 m) above sea level, and is native to California's southern Sierra Nevada mountains. Outside of its native range in California, Golden trout are more often found in cirques and creeks in wilderness areas around 10,500–12,000"+, often beyond 12,500"+ passes that are not passable without crampons, ice axes, and ropes until after the Fourth of July. Their preferred water temperature is 58 to 62 °F (14 to 17 °C) but they can tolerate temperatures in degraded streams on the Kern Plateau as high as 70 °F (21 °C) so long as those waters cool during the night. The only other species of fish indigenous to the native range of California golden trout is the Sacramento sucker (Catostomus occidentalis occidentalis).
O. m. aguabonita is native to the southern Sierra Nevada, including the upper reach and tributaries of the South Fork of the Kern River, and Golden Trout Creek and its tributaries. It has been introduced in hundreds of lakes and streams outside the native range, though most of these populations did not last or hybridized with cutthroat trout and other subspecies of rainbow trout.
Years of overexploitation, mismanagement and competition with exotic species have brought golden trout to the brink of being designated as "threatened". Introduced brook trout (Salvelinus fontinalis) outcompete them for food, introduced brown trout (Salmo trutta) prey on them and introduced rainbow trout (O. mykiss) hybridize with them, damaging the native gene pool through introgression. Populations have been in steady decline for decades.
In 1978, the Golden Trout Wilderness was established within Inyo National Forest and Sequoia National Forest, protecting the upper watersheds of the Kern River and South Fork Kern River. It also resulted in the closure of the Tunnel Air Camp airstrip and air charters operations for sport fishermen in the region.
In September 2004, the California Department of Fish and Game signed an agreement with federal agencies to work on restoring back-country habitat, heavily damaged by overgrazing from cattle and sheep, as part of a comprehensive conservation strategy.
The US Endangered Species Act (USESA) designated the subspecies O. m. whitei as LT, or Listed Threatened, since 1978, under the name Oncorhynchus aguabonita whitei.
