Recommendations for Restoration of Steelhead
Populations in California

August 1995

Submitted to
National Marine Fisheries Service
on behalf of
Association of California Water Agencies

prepared by
Steven P. Cramer
Donald W. Alley
Aldaron Laird
Jean E. Baldridge
William T. Mitchell
Keith Barnard
Robert C. Nuzum
Douglas B. Demko
Randall Orton
David H. Dettman
Jerry J. Smith
Jeff Hagar
Thomas L. Taylor
Thomas P. Keegan
Philip A. Unger

S.P. Cramer & Associates, Inc.
300 S.E. Arrow Creek Lane
Gresham, OR 97080

EXECUTIVE SUMMARY

This is the second of two reports we have prepared for submittal to the National Marine Fisheries Service (NMFS) for their use in determining if steelhead in California should be listed as threatened or endangered under the Endangered Species Act. This report focuses on recommendations for restoring healthy steelhead populations. We summarize restoration work that is already underway, and discuss further work that is needed.

ONGOING RESTORATION ACTIVITIES

Efforts to restore steelhead populations and their habitat have been substantial in several Califoria streams, and provide reason to expect improved steelhead production in the future on specific streams. These streams include, but are not limited to, the Sacramento River and its major tributaries, Lagunitas Creek, Pescadero Creek, San Lorenzo River, Zayante Creek, Soquel Creek, Browns Creek, Gamecock Creek, Corralitas Creek, Carmel River, Big Sur River, Santa Rosa Creek, San Simeon Creek, Choro Creek, Sespe Creek, Clear Creek, and Lompico Creek. Restoration activities include increased flows released from upstream reservoirs, capture and transport of fingerlings to permanent habitat and smolts to the ocean, rearing of fingerlings, closures of trout angling, gravel placement, installation of fish passage structures, riparian plantings, lagoon water level maintenance, and public education programs. In the Sacramento Basin, changes are being implemented in the mainstem such as increasing Delta outflow from February through June, improved fish passage facilities at Red Bluff Diversion Dam (RBDD), keeping RBDD gates open during late fall through early spring, closing the Delta Cross Channel gates from February through April, operating Shasta and Keswick dams and the Spring Creek Power Plant to provide cooler summer flows in the upper Sacramento River, installing temperature control devices at Shasta and Whiskeytown dams, and increasing minimum flow releases at Keswick Dam and RBDD.

NEW REGULATORY AND FINANCIAL AID MECHANISMS

New regulatory and financial mechanisms for expanding restoration efforts have recently been established. The Central Valley Project Improvement Act (CVPIA) requires development and implementation of a program designed to double natural production of anadromous fish in Central Valley streams by the year 2002. State and federal agencies signed an agreement in late 1994 to achieve improved water quality standards for the San Francisco Bay-Delta. The California Department of Fish and Game is allocating funds from a variety of sources (up to $2.7 million is available in 1994/95) to the public, nonprofit groups, and companies to complete habitat enhancement projects for salmon and steelhead. The California Wildlife, Coastal and Park Land Conservation Fund of 1988 (Proposition 70) provides funds for restoration and enhancement of salmon and steelhead streams, and up to $1.5 million will be available during 1995/96.

Our recommendations for recovery include both the gathering of information needed to make wise management decisions and the implementation of restoration activities.

RISK ASSESSMENT

We have recommended that the number of streams in which steelhead / rainbow rear and still have suitable habitat be used as the best measure for risk of extinction. Habitats in streams originating south of the Santa Lucia Mountains, at the southern fringe of the steelhead range, are only likely to be suitable for steelhead in cool, wet years. In these streams, the risk of extinction should be rated against the availability of cool-water refuges. Population trend alone should not be regarded as a reliable measure of the threat of extinction, because the populations fluctuate naturally in accordacne with long-term environment cycles. We conclude that anadromy has been historically interrupted in drought cycles in southern California streams, and is not a necessary trait to enable persistence of steelhead / rainbow there.

MONITORING AND RESEARCH

Monitoring of steelhead populations has been neglected, and priority should be assigned to establishing annual fish inventory sampling on several indicator streams within each ESU. Uniquely marked groups of smolts should be released on-station at each hatchery annually so that smolt-to-adult survival trends can be monitored and causes of variation analyzed, particularly the effects of the ocean environment. Additional genetics sampling should be completed to enable accurate assessment of ESU boundaries. The habitat carrying capacity for subyearlings, smolts and spawners should be estimated in streams designated to receive supplementation.

HARVEST

We recommend that harvest of wild fish, which occurs almost entirely in freshwater, be substantially restricted until ocean survival improves. Most of the estimates we found for harvest rates of adult steelhead were sufficiently high that steelhead populations could be damaged during years when ocean and freshwater survival are low. Trout angling in streams where steelhead / rainbow are designated for restoration should be curtailed. Particularly in the southern portion of the state, it will be necessary to resolve conflicting resource values between intensive fisheries for resident fish and intermittent opportunities to view or harvest anadromous fish.

SUPPLEMENTATION

Hatcheries will be an important tool for rebuilding steelhead populations, but hatchery practices must be substantially changed. Hatchery practices have probably contributed to a loss of genetic fitness in many streams, particularly on the north coast and in the Sacramento Basin. Outplanting of domesticated steelhead stocks should be discontinued, and the use of local wild broodstock should be developed. Naturally produced steelhead should be incorporated into the broodstock at any hatchery where hatchery fish are likely to interbreed with wild fish. Stocking of catchable trout from winter-spawning stocks should be prohibited in streams that may contain indigenous steelhead / rainbow. Juvenile salmon and steelhead rescues should be adopted as a form of supplementation in steelhead streams that become intermittent during years of low flow. Stocking of exotic species that may prey on juvenile steelhead, such as striped bass, should be stopped in waters that may support indigenous steelhead / rainbow.

HABITAT IMPROVEMENTS

We recommend a variety of measures. Water levels should be managed to maintain rearing habitat in lagoons that are breached artificially. Trapping and hauling of juvenile and adult steelhead around migration barriers should be considered in streams where suitable rearing habitat still remains upstream of the barrier. A refuge system should be adopted to include streams with good to excellent habitat, broadly distributed in each ESU, and that support steelhead populations large enough to avoid inbreeding depression. Implementation and evaluation of such habitat enhancements as addition of woody debris in pools, and replanting and protection of riparian zones should continue. Unscreened water diversions on steelhead / rainbow streams should either be screened or evaluated for the need to install a fish guidance device. Opportunities should be sought with water storage projects to provide pulses in flow that enable migration up or downstream of steelhead at critical times.