Cooperative fish rearing programs for salmon and steelhead have increased in recent years as public involvement in restoration activities has grown. All such operations require the written approval of the CDFG Regional Manager. Although there was initial resistance to private parties pursuing artificial culture programs, CDFG currently "strongly advocates involvement by the public sector where it is economically and operationally advantageous to fisheries" (CDFG, 1991).
Criteria for where projects are allowed, how they will be operated, what permits are necessary and all other requirements, are covered in the publication Cooperative Fish Production in California (CDFG, 1991). Relevant portions of this guiding document are summarized below. The Trinity River Restoration Program also has shown interest in use of small scale culture as a tool for rebuilding salmon and steelhead populations (Trinity River Technical Coordinating Committee, 1990). Policies adopted by the Program on "interim artificial propagation" are also discussed below.
Preventing Loss of Gene Resources
CDFG clearly states that "salmon and steelhead may not be taken from one stream or lake and put in a different stream without a specific permit from the Department." Any artificial propagation program within the South Fork Trinity basin would have to use stocks native to the watershed as a source of eggs or fry under these guidelines. CDFG guidelines currently allow transfer of fish over large geographic areas within a river basin. Concerns raised by Baker (1988) about loss of rare alleles due to hybridization of stocks throughout the South Fork watershed may not be addressed by current CDFG guidelines.
Facilities Are To Be Temporary
Part of the criteria for allowing such programs is a demonstrated ability and the necessary financial resources of cooperating non-profit agencies to fulfil their obligation. In general, CDFG assumes no obligation to aid continuing propagation operations if the cooperators are unable to continue on their own.
CDFG guidelines recognize that "natural production provides the great bulk of the State's salmon and steelhead resources. The Department's goal of maintaining and improving this production shall not become subservient to goals of publicly operated rearing programs." This is an affirmation that CDFG does not intend to allow operation of small scale rearing projects indefinitely in lieu of proper habitat protection. Consequently, small scale rearing projects are not envisioned as permanent facilities.
The Trinity River Task Force refers to small hatchery operations as "interim artificial propagation" in recognition of the temporary nature of these operations (TRTCC 1990). Guidelines define a "reasonable time for hatchery operation to increase native anadromous salmonids to carrying capacity "for a minimum of 2-3 years but not to exceed 2 fish life cycles (generally 6 to 8 years) depending on the target fish species and watershed conditions present at the time of implementation" (TRTCC, 1990).
To insure that small scale rearing goes hand-in-hand with increasing stream health, the Trinity River Restoration Program requires that there must be a "reasonable expectation that existing and future land and water management practices in the drainage will result in maintenance or improvement of fish habitat" (USFWS, 1990). Funding requests to the Program for small scale rearing projects require 1) information on water yield and quality, 2) a watershed assessment to define watershed stability and relative health, and 3) a projection of timber harvest activity for the next ten years in the watershed where the facility is to be located (TRTCC, 1990).
Site Selection for Hatching and Rearing
Salmon and steelhead require cold water temperatures to thrive and rearing conditions of hatchery ponds make high water quality even more important. The site for a small scale hatchery needs water that ranges between 42° and 56° F for incubation of eggs, and year around temperatures of 45° to 60° F for rearing ponds. Flows from the stream from which water is taken must be sufficient to provide good circulation even in late summer, while not unduly diminishing existing in-stream habitat quality and discharge within the natural channel. CDFG recommends a secondary water source be available, in the event of primary water system failure, to either avoid mortality of fish or preclude premature fish releases.
The proximity of the rearing site to a stream will facilitate developing a gravity fed water supply system, and allow the facility to utilize riparian rights which do not require special permits. If water is transported away from the riparian area, a State Water Resources Control Board (SWRCB) water permit may be required. All small scale hatchery site developments in streamside zones, and/or involving channel manipulations to extract water, require prior approval of CDFG under 1601-1603 permits regulations. The proposed hatchery site must not have a high risk of flood damage. Similarly, protection from vandalism or predators must also be assured. Optimally, the person responsible for hatchery operation should live on the premises to prevent vandalism and predation, and to deal with problems in a timely fashion. Other permits from the Army Corp of Engineers and the SWRCB may be required.
Disease Detection and Control
CDFG regularly conducts checks of fish health and treats disease problems as they arise. With the exception of using salt, no disease treatment can take place without a CDFG permit. The program operator must notify CDFG within 10 days prior to the release of fish for a final disease inspection. The Department reserves the right to deny the authorization to release fish or to order them destroyed, if the fish are found to be diseased. The prohibition on transfer of stocks between watersheds, and on importing broodstock from other states, are designed to preserve genetic diversity and prevent the spread of disease.
Trapping Weirs
Logistics of trapping wild fish are also a substantial concern. The hatchery should be located on a stream that has natural production of the species to be enhanced, but be currently "under-seeded" or under-utilized. If the program includes spawning and incubation, a weir site for trapping must be available. Even with careful planning, successful broodstock collection may be thwarted in some years due to high winter flows, droughts or low adult returns. CDFG guidelines for broodstock trapping at weirs require that they be "installed for a short period of time or deactivated on a regular basis to allow the majority of migratory fish to pass unhindered for natural spawning."
Hatchboxes
Hatchboxes are containers filled with gravel and "plumbed" to a cold water supply to imitate the natural incubation of eggs. This small scale rearing technique has been popular in the Oregon STEP program, but is not used widely in California at this time. Small "Heath Trays" are used for egg incubation at small scale hatcheries today. Operating hatchboxes without rearing ponds is thought to be of little value for steelhead and coho salmon because survival of fingerlings to adults is extremely low when fish are released as fry.
Rescue Rearing
Juvenile fish rescued by CDFG from above agriculture diversions where there is no avenue for successful downstream migration are sometimes reared to yearling size in pond programs. These so called "rescue rearing" facilities grow salmon or steelhead juveniles to a larger size, and release them into the native streams during periods of the year that offer the highest chance of survival.
There are several reasons that a restoration program for the South Fork Trinity River might employ a small scale hatchery operation. Small scale rearing can be used to increase seeding of under-utilized habitat and to achieve a self-sustaining increase in native fish populations. However, the California Department of Fish and Game (CDFG, 1993) asserts that "it is the responsibility of the proponent of any (small scale) rearing operation to satisfactorily demonstrate that an area proposed for 'supplementation' is, in fact, underseeded" before such a program could be approved. An alternative purpose would be to try to prevent extinctions of salmon or steelhead stocks through use of artificial culture. A third reason to employ small scale fish culture is to increase fish numbers available for harvest in the basin and in offshore fisheries.
The "Jump Start"
There is a widespread belief among residents of the South Fork Trinity basin, shared by some fisheries professionals, that in-stream habitat has recovered sufficiently, but that artificial supplementation is needed to increase fish populations (Tyrell, 1990). Therefore, there is considerable support for small scale rearing to "jump start" populations believing that once habitat is reseeded, fish populations will be self perpetuating and will remain at high levels. CDFG (1993) holds that "it has not been shown that underutilized habitat exists in the South Fork Trinity River."
Analysis of habitat quality (see Chapter III) has led to the conclusion that high levels of sedimentation and poor water quality are indeed limiting production of salmon and steelhead in many areas of the South Fork Trinity basin. The fundamental assumption that habitat is not limiting is brought into question by these low fish densities. Given this baseline information, achieving long term benefits from an artificial propagation program is likely to be difficult. Harvest of fish could also lead to under escapement and will be examined in the discussion below of supplementation for the purpose of harvest augmentation. Habitat bottlenecks in the main river, estuary, or elsewhere can also limit survival and thwart the success of small scale hatcheries after fish are released.
There is strong evidence that shifting bedload is limiting chinook salmon egg and alevin survival in the South Fork Trinity River (CDWR, 1982; Mike Dean, personal communication). A case study from the Oregon coast illustrates why increasing spawners can not garner sustainable benefits when severe sedimentation problems exist. The Oregon Department of Fish and Wildlife attempted supplementation of Euchre Creek, a small coastal stream south of Port Orford, Oregon. Chinook salmon stocks had dropped from approximately 2,000 fish to about 200 to 500 as a result of habitat damage related to sedimentation (Frissell and Liss, 1987).
Chinook salmon juveniles from the nearby Elk River Hatchery were planted in flat areas of the stream thought suitable for spawning. Dozens of adult salmon homed to these areas three years later and spawned. Nawa et al. (1990, 1991) measured changes in the gravel bed adjacent to redds and found that, even during a low to moderate storm (2 year event), scour and fill of the stream bed was sufficient to wash eggs down stream or bury them so deeply that fry could not emerge. Dive surveys the following spring found no survival of juvenile chinook salmon in these reaches. Attempts at reseeding streams with poor spawning habitat and unstable channel conditions will rarely result in permanently increased fish populations.
Wilson and Mills (1991, 1992) found that very few South Fork Trinity River steelhead survive to adulthood unless they spent two to three years in a fresh water environment before entering the ocean. USFS habitat typing reports show that carrying capacity for these older age juveniles in cold water tributaries is limited (USFS, 1990b; Dale 1990). Steelhead juveniles in their second and third year of residence tend to move into main river habitats. However, habitat surveys of the main stems of the South Fork and Hayfork Creek indicate that major portions of these streams are too warm to serve as suitable habitat in the late summer.
Wilson and Mills (1991; 1992), in studying tributaries to the South Fork, found that thousands of young of the year (0+) steelhead move downstream in May each year to avoid competition with older age classes of fish, and to find available habitats to colonize. Few of these fish were found in mainstem habitat typing surveys, and data suggest few survive to return as adults. Results of these studies indicate that main stem habitat temperature problems in the South Fork and Hayfork Creek are limiting survival of both younger and older age steelhead. Summer in-stream rearing conditions in the main stem of the South Fork Trinity River may also be limiting chinook and coho salmon production. Juvenile chinook salmon from the South Fork show some of the poorest growth rates of any stock in the Klamath basin (Sullivan, 1989). Small scale culture is unlikely to successfully offset these fundamental ecological bottlenecks.
The "Jump Start" Combined with Habitat Restoration
Some success has been achieved in restoring fall chinook salmon populations in Horse Linto Creek on the lower Trinity River through a cooperative effort between the California Department of Fish and Game, Six Rivers National Forest, and the Pacific Coast Federation of Fishermen's Associations (Buck, 1990). Small scale culture of native salmon returning to the basin was used in conjunction with habitat restoration. Horse Linto Creek experienced considerable impacts during the 1964 flood, resulting in loss of stream habitat diversity, reductions in pool volume and frequency, and changed particle size distributions of the substrate. The channel of the stream lacked depth, cover, and sorting of appropriate gravels for spawning.
Restoration actions were undertaken to reduce sediment inputs and to stabilize several active streamside slides. Log and boulder weirs were installed to trap spawning gravels and create pools. A small scale wild fish capture and rearing program was also implemented which only used fish from Horse Linto Creek. The number of spawning salmon in the basin has increased from a few dozen, when the program began in the early 1980's, to several hundred in 1992 (Dave Hillemeyer, personal communication). There is still some skepticism within CDFG that there will be sustained benefits from the Horse Linto Creek project when the rearing program is discontinued (CDFG, 1993).
Few tributary streams within the South Fork Trinity River basin have the potential to serve as host basins similar to Horse Linto Creek. Most tributaries have either impassable barriers near their convergence with the South Fork or a steep stream gradient unsuitable for salmon spawning. It makes little sense to increase salmon spawning to a high level in a stream that has insufficient capacity for natural production. Hayfork Creek has a suitable channel gradient for salmon access and spawning but problems with water temperatures and low flows must be remedied or small scale rearing will have no lasting benefit.
The Life Line
Spring chinook salmon, coho salmon, and summer steelhead are at extremely low population levels in the South Fork Trinity basin (Chapter II). Higgins et al. (1992) classified the spring chinook stock as at high risk of extinction. For chinook and coho salmon, there is evidence that frequent channel changes during high winter flows disrupts gravel redds and may be one of the primary factors limiting the survival of eggs and alevin (larval fish). Therefore, it follows logically that small scale rearing programs could be initiated to increase survival of this vulnerable life history phase. Several factors make implementation of such a program more difficult than it might seem at first.
Spring chinook and summer steelhead enter the South Fork Trinity River from April through June, but do not spawn until fall or early winter. Recent attempts by the National Marine Fisheries Service to artificially culture threatened Sacramento River winter run chinook give some indication of how difficult working with fish with delayed spawn timing may be (Foott, 1990b; Forbes, 1991). Sacramento winter chinook return to the river in January and February but spawn from April through July. Because these fish are listed under the Endangered Species Act, the rearing effort has a very, very large budget. Separate tanks have been constructed at Coleman Hatchery that are supplied with chilled, ozone treated water to reduce disease organisms (Forbes, 1991). Fish are also treated with Malachite green, an anti-fungal agent. Female fish are injected with hormones to advance sexual maturation. Despite the state-of-the-art hatchery technology associated with this program, very few fertilized eggs have been obtained during three years of operation (Scott Foott, personal communication).
It is unlikely that any small scale rearing program in the South Fork Trinity basin will receive funding and resources presently available to the Sacramento River winter run chinook salmon program. Therefore, it is unlikely that spring chinook or summer steelhead could be successfully held until ripe for spawning. An alternative strategy for capture and spawning would be to wait until just prior to natural spawning. The logistical problem of the remoteness of spawning sites makes this strategy equally difficult. A restoration program for spring chinook in rivers draining into Puget Sound in Washington used helicopters to transport adults from natural spawning areas (Wunderlich and Boomer, 1984). The feasibility of this method might be explored if a South Fork Trinity River spring chinook rearing program is considered.
No information is available on where summer steelhead spawn, so much more research would be required before the feasibility of small scale culture of that species could be assessed. There are indications that native coho salmon return to the South Fork Trinity River during January (Jong and Mills, in press) when operation of a trapping weir in the mainstem would be difficult during most years.
When populations of any animal drop to critically low levels, genetic diversity can become a factor in extinction (Gilpin and Soule, 1990). If we increase mortality of a South Fork Trinity stock of salmon or steelhead that is already at or below these thresholds, while attempting small scale culture, there is always the risk that we may hasten their extinction instead of prevent it. Artificial rearing that threatens population viability is also a violation of CDFG guidelines (CDFG, 1991). Chapter 9 Continued