TROUT 101 - THE WHAT, WHEN & WHY
What is a Trout?
Trout is the common name given to a number of freshwater fish species belonging to the salmon family, Salmonidae, and include three genera: Genus Salvelinus (often refered to as "char"), Genus Salmo which includes Atlantic species and Genus Oncorhynchus which includes Pacific species. Trout have no spines on the fins, and all of them have a small adipose fin along the back, near the tail.
Where are trout found?
Trout are usually found in cool, clear streams and lakes, and are distributed naturally throughout North America, Asia and Europe. Several species of trout were introduced to Australia and New Zealand by fishing enthusiasts in the 19th century. In California, trout thrive in a number of environments. Steelhead are found in coastal watersheds, many native species ply the high mountain creeks of the Sierras and rainbows and browns can be found all over the state.
Why are trout important?
Trout are important for a number of reasons but perhaps their primary importance is as an "indicator species". When trout disappear from a lake or river, that watershed is in trouble. Trout are referred to as "cold water fish" because, unlike a number of other species, they prefer cold, clean and often free-flowing water. When our streams and rivers, slow down, dry out or heat up, it's the trout that are the first to feel it.
Trout are also considered by ecologists to be a 'keystone' species for watersheds. Keystone species are those that, if they die off, leave critical gaps in the ecosystem that cannot be filled by other species. If trout are removed from a river system, for instance, the many aquatic insects that they feed on overpopulate, resulting in destruction of aquatic vegetation. Meanwhile, bears and birds and other land vertebrates that feed on trout are left without an important food source.
What Are "Wild Trout"?
When we talk about trout at CalTrout we usually mean wild trout. Unlike hatchery fish that are farmed and planted expressly for recreational fishing, wild trout live and breed naturally in the state's watersheds. While hatchery-reared fish have their place in California, wild trout remains CalTrout's primary focus.
Steelhead, a trout or not?
The steelhead is an anadromous species of trout, native to the west coast. Anadromous fish, like Salmon, are born in fresh water, mature in the ocean and return to freshwater (often the stream of their birth) to spawn. Unlike Salmon, however, steelhead do not necessarily die after spawning and can make the run between fresh and salt water several times. Because their habitat, appearance, and life cycle is so different from other trout species, they are often singled out as a separate species.
Many species of wild trout are actually immigrants. Species like the brown and some rainbow trout species were introduced into California's lakes and rivers many years ago where they continue to thrive and are protected under the Wild Trout Program.
Heritage trout, however, refers to those species that were here long before our state was called California. So, while all heritage trout are wild trout, not all wild trout are heritage trout.
California's Heritage Trout
No state can compete with California's diversity of native trout species. Its 60 major watersheds include over 20,000 miles of rivers and streams (Source: FRRAP, 1988.). These waters support 10 native trout species, the majority residing in the Sierra Nevada. California, however, also leads the nation in the number of extinct or imperiled aquatic species (Source: Moyle and Williams, 1991.). The problems for the State's native trout species are particularly acute in the Sierra Nevada, where river systems are the most altered and habitats impaired by logging, mining and grazing (Source: SNEP, 1996.).
A brief assessment of the status and health of these 10 native trout species is presented below. The assessment designates their health and general risk level according to four categories: extinct, at high risk, at moderate risk and not at risk.
California Bull Trout: While Bull Trout populations still remain in other western states, no Bull has been caught in California since the 1970's. Before their disappearance, they were found in the McCloud River in Siskiyou and Shasta counties.
At High Risk
Paiute Cutthroat Trout: This is the rarest trout in California and one of the most imperiled species in the state. Limited to two small populations surviving in Silver King Creek in the Humboldt Toyabi National Forest and the Inyo National Forest, the Paiute is listed as threatened under the Endangered Species Act. Presently there are only about 500 Paiute trout over six inches. The two primary reasons for their diminishing numbers are habitat loss caused by overgrazing and the introduction of non-native trout species including rainbow and brown trout.
California Golden Trout: Once called the Volcano Creek Golden Trout, this species was designated as the State Fish by the California Legislature in 1947. Their range encompasses approximately 120 miles of stream habitat found mostly within the Golden Trout Wilderness high in the Sierras. The California golden trout is a State Species of Special Concern (Source: Fish Species of Special Concern in California, CA DFG, Second Edition, June 1995.) and a Forest Service classified Sensitive Species. The golden is the most likely California-native species to be federally listed as endangered, due to habitat degradation, primarily by livestock, and planting of non-native trout species.
Native Trout Populations at Moderate Risk
McCloud River Redband Trout: This unique and colorful rainbow trout subspecies is native only to the McCloud River and tributaries above Middle Falls near Mt. Shasta. Redbands populate about 60 miles of stream habitat but their numbers have been reduced by competition with non-native trout, primarily German browns. Hybridization with introduced rainbow trout and deficient late summer flows are also a problem. The McCloud River redband trout is a State Species of Special Concern and is a candidate for federal listing.
Eagle Lake Rainbow Trout: This rainbow trout subspecies is confined to Eagle Lake near Susanville in Northern California. The Lake's population is a robust one. However, the fish are spawned in a local hatchery as their historical spawning grounds (Pine Creek) go dry at certain times during the year due primarily to cattle overgrazing. The fish is presently listed as federally threatened.
Lahontan Cutthroat Trout: This cutthroat species historically occurred throughout the Walker, Carson, Truckee and Honey Lake drainages including Lake Tahoe, Donner and Fallenleaf Lake. Today, the Lahontan population is restricted to 14 streams in the Lahontan drainage with about 23 miles of occupied habitat, as well as 720 acres in Independence Lake. Presently the population consists of less than 10,000 adult fish. The Lahontan cutthroat trout is a federally listed threatened species due primarily to past overgrazing. Currently, the Lahontan is considered stable and a population has been re-established in the Upper Truckee River.
Goose Lake Trout: This rainbow trout species occurs in Goose Lake and most of its tributaries, as well as some of the tributaries of the Pit River. Historically, significant spawning runs consisting of thousands of 2-5 pound trout occurred in most suitable tributaries and provided a popular trophy fishery. Today, most of the spawning runs are blocked by diversion dams and are de-watered for irrigation purposes. The California Department of Fish & Game (DFG) feels that, despite the drought of 1992-93 which caused the lake to dry out completely, there is a good chance for the population to stabilize and even grow. And in tributaries such as Lassen Creek, several hundred Goose Lake trout have been seen spawning. The Fish and Wildlife Service wants to see the trout listed while the DFG feels that they should not be.
Warner Lake Redband Trout: This rainbow trout subspecies was isolated in Warner Lake approximately 15,000 years ago. Evolutionary changes during their long period of isolation resulted in a unique strain of trout. Human impact over the last 150 years has resulted in the fragmentation and diminishment of the marsh/lake/stream systems. Basin floors were developed for agriculture, which included extensive damming, channeling, draining and loss of marshlands. Irrigation diversions were constructed on most streams causing de-watering and physical blockages for both upstream and downstream migrating trout. Cattle grazing also contributed to channel destruction in some locations. In several cases, the loss of adjacent marshlands appears to be related to increased alkalization. Lake and marsh rearing habitat and functioning migration corridors have been lost as a result. Exotic warm water species have infiltrated and spread.
Native Trout Populations Not at Risk
Little Kern River Golden Trout: This colorful rainbow trout subspecies is native only to the Little Kern River drainage. In 1978 this species was listed as threatened. However, because of long and expensive restoration efforts, the Little Kern golden trout is now restored to 80 miles of stream habitat. It is likely to be the first species in California to be de-listed. Because of unauthorized plantings of exotics this may cause a delay in this de-listing.
Kern River Rainbow Trout: This rainbow subspecies formally occurred throughout the Kern River drainage but is now limited to the mainstem, upstream of the Little Kern River where it occupies about 30 miles of stream habitat. The Kern River rainbow is a State Species of Special Concern primarily as a result of hybridization with planted rainbow trout. The current population is relatively stable and is not federally listed.
Coastal Cutthroat Trout: The coastal cutthroat trout's range occurs from the lower Eel River north to Seward, Alaska. To date, 182 populations occupying 650 miles of stream habitat have been documented in California. In addition, they occur in five coastal lagoons with 4,500 acres of habitat. The best population occurs in the Smith River drainage where 14-18 inch fish are common. This population is considered stable and is not federally listed, but is listed as a State Species of Special Concern.
The source of this article is California Trout, Inc. • 870 Market Street, Suite 528 • San Francisco, CA 94102 and can be found on the internet at www.caltrout.org.