LIFE HISTORY, DISTRIBUTION, RUN SIZE AND ANGLER HARVEST OF STEELHEAD IN THE SOUTH FORK TRINITY RIVER BASIN (continued)
The Sandy Bar Weir operated from 5 September 1991 through 11 February 1992, trapping 493 adult fall- and winter-run steelhead. The first steelhead was trapped on 5 October 1992 (Figure 3). Steelhead entered the SFTR basin throughout this period. Immigration peaks occurred during late October, November, and January. We believe we monitored the entire fall-run population and most of the winter-run population of adult steelhead immigrating past Sandy Bar, although we know that the run continued after 11 February 1992 based upon immigrants trapped at our upper SFTR basin weirs (Hayfork Creek, Forest Glen and Gates Road weirs) later in the season. The timing of the steelhead runs seems to depend more on environmental conditions (storm events with accompanying high flows) than calendar dates. The periodic increases in steelhead capture numbers at the Sandy Bar weir directly coincided with storm events.
Twenty-one of the 493 steelhead captured at the Sandy Bar Weir carried tags previously applied at the Willow Creek Weir; 612 steelhead tags were applied at Willow Creek (personal communication, Michael Lau, Calif. Dept. Fish and Game). We tagged the remaining 472 fish with $10-reward anchor tags and gave all 493 steelhead 1/2 LV fin clips. Mean FL of all 493 steelhead examined was 63 cm (Figure 4). Gillnet scars (20.1%) and predator scars (57.2%) were the most common scars seen on steelhead trapped at the weir (Table 2). Travel times for the 21 fish previously tagged at the Willow Creek Weir ranged from one to 71 days, and averaged 27.5 days (Appendix 2).
The creel survey was conducted on the SFTR between 1 November 1991 and 14 March 1992, an interval of 135 days. The lower survey section (Figure 2) was monitored for angler activity on 102 days and a creel survey conducted on 73 days of this period. The upper survey section was monitored for 135 days and a creel survey conducted on 93 days of this period. Creel surveys were not conducted when high flows made the river unfishable. The river in the lower survey section was subjectively judged to be "unfishable", due to high-flows and turbidity, after 11 February 1992. At this point we ceased surveys in the lower section. The upper section was judged "unfishable" for nine (9.6%) of the days it was monitored.
During the survey, 283 anglers were interviewed, 13 (4.6%) within the lower section and 270 (95.4%) within the upper section. Peak angling activity (54.2%) was observed within the upper survey section at the Hayfork Creek mouth, Little Rock Campground, and Big Slide Campground, with the rest of the anglers' effort distributed over a range of other sites. Of the 283 anglers interviewed, 48 were observed fishing at multiple locations on the same day. Each site of angling activity was counted, but an angler was not recounted when observed at a different location on the same day (Table 3).
Forty-two adult steelhead and one adult chinook salmon were observed in the catch (10 steelhead and one chinook salmon in the lower section and 32 steelhead in the upper survey section). One half-pounder and one juvenile steelhead were also observed in the upper section. Eighteen of the 42 adult steelhead observed carried tags from Sandy Bar Weir (three in the lower survey section and 15 in the upper survey section). Based on extrapolations of the creel survey data, an estimated 79 anglers within the lower section landed 59 adult steelhead and five chinook salmon (Table 4), while an estimated 1,501 anglers within the upper section landed an estimated 165 adult steelhead, two half-pounder steelhead, two juvenile steelhead and no chinook salmon (Table 5).
County of origin was tabulated for all 283 anglers. The majority (93.6%) of the anglers fishing within the SFTR basin were from Trinity county (Table 6).
Excluding the unfishable days, water clarity ranged from 55 to 150+ cm in the lower survey section and from 17 to 150+ cm in the upper survey section. Water temperatures ranged from 2.2 to 13.3E C and averaged 7.2E C in the lower survey section, while the upper survey section ranged from 3.3 to 15.6E C and averaged 7.8E C.
Fifty-three of the 472 tags applied at the Sandy Bar Weir were returned by anglers through the mail indicating a harvest rate of 11.3%. However, only 10 of 18 tags observed in the creel survey were later returned by anglers indicating a response rate of 55.6%. Dividing the number of tags returned through the mail by this response rate gives us a corrected tag return of 95.3 tags, yielding a corrected harvest rate of 20.2% for adult steelhead (95% Poisson confidence interval [C.I.] = 15% to 26%).
Walking surveys were conducted throughout the SFTR basin between 3 April and 1 June 1992 to document numbers and locations of spawning steelhead (Table 7). We surveyed and habitat-typed sections of 26 creeks (134.4 km total length), counted and flagged 262 redds, and observed nine adult steelhead.
The East Fork of the South Fork Trinity River and Eltapom Creek contained the highest redd densities of all creeks surveyed (15.0 and 10.0 redds/km, respectively), followed by Plummer Creek and Smokey Creek (7.9 and 5.9 redds/km, respectively). These same four creeks also had the highest observed densities last year. These areas of high redd concentration all had good spawning habitat and were contained in drainages that are fairly stable geologically, and have not been too adversely affected by logging activities or by the catastrophic 1964 flood. The lowest redd densities were found in the Hayfork Valley in creeks affected by livestock grazing or poor logging practices, both of which contribute to heavy siltation of the creeks. Most creeks in the SFTR basin show signs of progressive habitat degradation due to the sedimentation of stream systems, resulting in the loss of appropriate spawning gravel sites and the filling in of pools. The low-flow conditions during the past six years of drought has probably intensified the problem by restricting spawning to the more degraded areas of stream systems.
We surveyed seven tributaries to the SFTR and two tributaries to Hayfork Creek, all within the Hyampom Valley, between 8 April and 1 June 1992. These surveys covered a total of 13.2 km of stream. We observed 23 redds and four live adult steelhead (Table 7).
Big Creek. Big Creek, a small tributary to the SFTR (RKM 42.8), is located 5.6 km downstream from the town of Hyampom. A natural barrier of cascades exists 0.8 km upstream from the confluence and a hydropower plant is located adjacent to the creek 30.5 m below the cascades. We surveyed the 0.8 km of Big Creek from the confluence to the barrier on 10 April 1992. The stream bed contains numerous pools and large boulders but lacks suitable spawning gravels to support much spawning activity. The only spawning area available is found in the gravels in front of the culvert exiting the powerhouse. One redd was observed there.
Butter Creek. Butter Creek, a tributary to the SFTR (RKM 54.2), is located 3.2 km south of the town of Hyampom. This creek contains areas of extreme bank sloughing in the lower 0.4 km section due to early logging activities exacerbated by the floods of 1964 and 1986. However, most of the creek upstream of this area contains large holding pools and some areas of suitable spawning habitat. Butter Creek Falls exists 2.4 km from the confluence creating a natural barrier to anadromous fish passage. We surveyed the 2.4 km below the falls on 21 April and 1 June 1992, counted five steelhead redds and observed two adult steelhead.
Corral Creek. Corral Creek, a tributary to Hayfork Creek (RKM 10.0), is located east of the town of Hyampom. Corral Creek is a medium-sized stream with mountainous headwaters which flows through a narrow, steep-sided canyon. A slide has created a complete barrier to anadromous passage 0.2 km from its confluence with Hayfork Creek. Watershed vegetation consists of dense stands of douglas fir, ponderosa pine, and mixed hardwoods. Cascades and pools are abundant but areas of suitable spawning gravel are scarce. We surveyed the lower 0.2 km of Corral Creek on 22 April 1992 but observed no redds or adult steelhead.
Eltapom Creek. Eltapom Creek, a tributary to the SFTR (RKM 40.9), is located 8.0 km north of the town of Hyampom and flows through a narrow canyon consisting of steep rock and oak covered slopes which were badly damaged by fire in 1987. Pools and spawning habitat are very common throughout, with spawning gravels in the upper reaches less compacted and more suitable for spawning than those in the middle and lower reaches. Pools are numerous and pool cover consists mostly of root-wad and bedrock structures. Riparian vegetation is fair, with creek canopy consisting mainly of alders. A waterfall exists 1.3 km from the confluence, creating a natural barrier to anadromous fish passage. We surveyed the lower 1.3 km of the creek on 8 April and 18 May 1992 and counted 13 redds.
Grouse Creek. Grouse Creek, a tributary to the SFTR (RKM 31.1), is located north of the town of Hyampom. The stream has a complete barrier (Devastation Slide) to anadromous fish passage 2.6 km from its confluence with the SFTR. The lower 2.6 km section has a high gradient, and the few areas containing available spawning gravel are highly cemented with sediment. A geological assessment of the Grouse Creek barrier was completed by the U. S. Forest Service, Lower Trinity River Ranger District in 1989 and indicated that rearing conditions above the barrier for juvenile salmonids are fair to good. We surveyed the lower 1.6 km of Grouse Creek on 27 April and 7 May 1992 but counted no redds or adult steelhead.
Kerlin Creek. Kerlin Creek, a tributary to the SFTR (RKM 44.3), is located in the Hyampom Valley. Kerlin Creek flows through a gulch with highly eroded cliffs approximately 5.0 m in height. Many of the riparian trees along the creek are undercut and in the streambed. The stream substrate is composed predominately of cobbles, mostly about 30 cm in their largest dimension. Kerlin Creek contains no suitable pool habitat and the spawning gravel generally suffers from heavy siltation and sedimentation. We surveyed the lower 2.4 km of Kerlin Creek on 16 April and 22 May 1992, and observed one redd but no adult steelhead.
Madden Creek. Madden Creek, a tributary to the SFTR (RKM 2.4), is located just west of the town of Salyer and south of the town of Willow Creek. The creek flows through a steep and heavily forested drainage, with anadromous fish habitat confined to the lower 1.9 km. The drainage has experienced extensive timber harvest and fine sediments are accumulating in the watershed. We surveyed Madden Creek from the mouth upstream for 1.9 km on 30 April and 27 May 1992, but observed no redds or adult steelhead.
Olsen Creek. Olsen Creek, a tributary to Hayfork Creek (RKM 0.6), is located just east of the town of Hyampom. The USFS has put in numerous fish habitat improvement structures in this system, but spawning habitat is limited. The upper 2.4 km section runs through a steep narrow canyon containing numerous falls ranging between 1.1 and 4.6 m in height, which may be natural barriers to anadromous fish passage. Two debris blockages in the lower 0.8 km which were believed to be complete barriers in past years, except during very high flow conditions, were removed by the California Conservation Corps (CCC) prior to this year's survey. We surveyed the lower 1.8 km of the creek on 9 April and 13 May 1992, and observed three redds and two live adult steelhead.
Pelletreau Creek. Pelletreau Creek, a tributary to the SFTR (RKM 46.7), is located west of the town of Hyampom. Only the uppermost section contains adequate holding pools, while the remainder of the creek is composed mainly of a cemented gravel substrate, unsuitable for spawning. This creek was severely damaged by the 1964 flood and is reported to have 10.7 m of gravel sitting on top of the original creek bed in this lower section. Pelletreau Creek contains a cascade barrier to anadromous fish passage 0.8 km upstream from its mouth. Although this is a perennial stream, complete water diversion during summer months leaves the lower 0.3 km section dry. We surveyed the lower 0.8 km of the creek on 21 April and 19 May 1992, and observed no redds.
We surveyed 12 tributaries to Hayfork Creek, plus parts of the mainstem of Hayfork Creek between 3 April and 29 May 1992. These surveys covered a total of 96.7 km of stream, and we observed 94 redds and counted four adult steelhead (Table 7).
Big Creek. Big Creek, a major tributary to Hayfork Creek (RKM 43.8), is located in the Hayfork Valley east of the town of Hayfork. This creek has been very productive in the past, with spawning gravel fairly abundant in the middle and upper survey sections. Pools are common, and riparian vegetation is medium to dense. The USFS and California Conservation Corps (CCC) crews have installed numerous fish habitat enhancement structures in this creek. During the winter months, the habitat is excellent. However, a property owner diverts most of the creek for watering livestock pastures during the rest of the year. The water diversions are located 2.4 km and 4.8 km upstream from the confluence with Hayfork Creek, and limit the habitat for fish in this lower section. We surveyed the lower 14.0 km of the creek between 9 April and 8 May 1992, counted 53 redds and observed one adult steelhead.
Carr Creek. Carr Creek, a tributary to Hayfork Creek (RKM 47.8), flows through part of the upper Hayfork Valley. This valley section is heavily impacted by livestock, the riparian zone is heavily grazed, and cattle crossings are numerous, causing heavy suspended sediment throughout the section. Beaver dams are numerous throughout the creek, with one causing a total fish passage barrier below the Double G Ranch. Spawning habitat is limited, pools are small (most less than 1.0 m deep) and several low water barriers exist. We surveyed the lower 4.3 km of Carr Creek on 4 May 1992 and observed no redds or adult steelhead.
Dubakella Creek. Dubakella Creek, a tributary to upper Hayfork Creek (RKM 78.4), is located south of the town of Wildwood. The upper 2.1 km section flows through a steep narrow canyon containing mostly cascades with accompanying high-velocity flows. The slope gradient levels out in the lower 1.1-km section, but sections with spawning gravel are limited. Large and small woody debris cover is abundant throughout this stream system and the riparian zone vegetation consists primarily of alders. We surveyed the lower 1.6 km of the creek on 24 April 1992 and observed no redds or adult steelhead.
East Fork of Hayfork Creek. The East Fork of Hayfork Creek, a major tributary to Hayfork Creek (RKM 58.2), is located north of the town of Wildwood. The creek is very rocky in many areas, but does contain areas of good spawning habitat, mainly where the CCC crews have built spawning gravel recruitment structures. Most of the spawning activity we noted has occurred in the latter areas. The upper 3.2-km section contains numerous pools and riffles, and areas of spawning gravel are abundant. The remaining 4.2 km, from the East Fork Road bridge to its confluence with Hayfork Creek, is a steady, declining gradient containing fast-moving water and little spawning habitat. The primary riparian zone consists of alders and willows. Secondary growth consists of cedars, firs, and pines. Most of the basin has been hydraulically mined. These operations are most evident in the main basin in the form of large tailing piles. In general, nearly all of the East Fork of Hayfork Creek drainage has been altered from its natural topography. We surveyed 8.4 km of the East Fork of Hayfork Creek on 7 April and 5 May 1992, from its confluence with Hayfork Creek to the confluence with the North Fork of the East Fork of Hayfork Creek, observing 5 redds.
Goods Creek. Goods Creek, a tributary to Hayfork Creek (RKM 45.6), is located near Wildwood. Steelhead habitat was poor due to the low flow conditions, spawning areas were limited, and creek sedimentation was heavy. A beaver dam, which caused a barrier to anadromous fish migration in 1990, had been removed. We surveyed the lower 1.4 km on 29 April 1992, and observed no redds.
Hayfork Creek. Hayfork Creek is the major tributary to the SFTR (RKM 30.1). Most of the creek above the Hayfork Valley is composed of boulders and large rubble unsuitable for spawning. Some upper reaches of Hayfork Creek contain a few areas of suitable spawning habitat, but beaver dams are creating a serious siltation and sedimentation problem resulting in cemented gravels. The section flowing through the Hayfork Valley contains a minimal amount of spawning gravel, but the habitat is poor, with little or no cover, very few pools, and warm water temperatures in the summer. We surveyed sections from the upper Hayfork Valley at the Dubakella Creek confluence to the confluence of the SFTR in those areas that were accessible and where we knew spawning habitat existed. We surveyed 31.1 km of the creek between 22 April and 29 May 1992, and counted 10 redds and two adult steelhead.
Little Creek. Little Creek, a tributary to Hayfork Creek (RKM 29.0), is located west of the town of Hayfork. The USFS has constructed habitat improvement structures in the stream, and there are areas of suitable spawning habitat. We surveyed the lower 2.3 km of the creek between 7 May and 21 May 1992, and counted four redds and one adult steelhead.
Philpot Creek. Philpot Creek, a tributary to Salt Creek (RKM 11.1), is located in the Hayfork Valley. It is composed of long stretches of bedrock substrate and contains some areas of suitable spawning gravels. A dense canopy of riparian vegetation makes walking the stream in its lower section impossible. We surveyed the lower 2.1 km of the creek on 8 April 1992 and counted no redds.
Potato Creek. Potato Creek, a tributary to East Fork of Hayfork Creek (RKM 3.1), flows through an extremely steep-sided basin in the upper reaches, which gradually moderates toward its mouth. The streambed itself is also very steep with cascades becoming frequent 2.4 km upstream from its confluence with East Fork of Hayfork Creek. Potato Creek flows in a northerly direction surrounded by moderately dense stands of douglas fir, alder, and maple. Spawning gravels are less abundant in the upper reaches, however, juvenile rearing habitat is available. We surveyed the lower 2.4 km on 8 April and 9 May 1992, and counted one redd.
Rusch Creek. Rusch Creek, a tributary to Hayfork Creek (RKM 28.5), is located west of the town of Hayfork. This is a perennial stream running through mountainous terrain with fairly dense shade canopy provided by Douglas fir, yew trees, bigleaf maple, and alder trees. The creek contains numerous fish habitat improvement structures for bank stabilization, pool scouring, and spawning gravel recruitment, but spawning habitat is very limited. The upper 3.2 km are very steep, with many cascades and no spawning habitat present. Steelhead rearing habitat was fair throughout the creek. Pools were primarily boulder- and log-formed, with pool cover provided mostly by rock and woody debris. Several complete and low-flow barriers were noted 6.0 km from the confluence. We surveyed the lower 6.0 km of the creek between 23 April and 13 May 1992, and counted no redds.
Salt Creek. Salt Creek, a major tributary to Hayfork Creek (RKM 37.0), runs through the Hayfork Valley. The lower section flows through pasture land where the creek is very open and exposed, and steelhead habitat is poor. Some pools are present but are lacking in cover, with the riparian vegetation consisting of alders and willows. The upper and middle sections contain better habitat with deeper pools and a denser canopy. Spawning habitat exists, but many of these areas are located within pastures and contain numerous cattle crossings, disturbing available spawning areas. Riparian vegetation is also heavily grazed, reducing cover and increasing sun exposure. We surveyed Salt Creek from its mouth upstream for 17.1 km between 15 April and 23 May 1992, and counted 8 redds.
Tule Creek. Tule Creek, a tributary to Hayfork Creek (RKM 35.9), flows through the Hayfork Valley. Spawning habitat in the lower section is poor, due to a clay hardpan substrate. The upper section contains many large, deep pools, and spawning habitat is more readily available. Primary riparian cover is alders and oaks. CDFG personnel removed a beaver dam located in the lower 4.0 km, which was a low-flow barrier during spring 1990. We surveyed the lower 6.0 km of the creek on 3 April and 11 May 1992, and observed thirteen redds.
We surveyed five tributaries to the SFTR in the upper SFTR basin area between 1 and 29 May 1992. These surveys covered 24.5 km of stream, and we observed 145 redds and one adult steelhead (Table 7).
East Fork of the South Fork Trinity River. The East Fork of the SFTR, (RKM 118.0), is located in the Yolla Bolla region south of Highway 36. The upper 3.2-km section flows through a rugged, steep-sided canyon and is composed mostly of riffles and runs, while the lower section levels out into a low-gradient stream that is composed predominantly of cascades and large, deep pools. Spawning gravels were found throughout the surveyed section. We surveyed the lower 5.2 km on 7 May 1992, and counted 78 redds.
Plummer Creek. Plummer Creek, a tributary to the upper SFTR (RKM 70.3), flows through a steep-sided canyon. Firs and alders dominate the canopy, while aquatic and riparian vegetation provide plentiful stream cover. Spawning gravels were plentiful and located mainly at the ends of pools. Few runs were observed due to the fairly steep gradient of this section. Many of the firs growing on the canyon slopes were burned during the Friendly Fire of 1987. A slide which dammed the stream and was then blown out with high flows is located approximately 1.2 km above the confluence with the SFTR. The quality of habitat below the slide is poorer than that above; pools in the lower reach are filled in, riparian vegetation has been removed, and spawning gravels show signs of sedimentation. Our survey crew was of the opinion that the slide occurred after the fire. We surveyed the lower 3.4 km of Plummer Creek on 5 May 1992, and counted 27 redds.
Rattlesnake Creek. Rattlesnake Creek, a tributary to the SFTR (RKM 91.7), is located in the Forest Glen area. The upper and middle sections contain spawning habitat, but the lower section is composed mainly of cascades and very large pools. We surveyed the lower 10.6 km of the creek on 1 and 29 May 1992, and counted 19 redds and one adult steelhead.
Silver Creek. Silver Creek, a tributary to the SFTR (RKM 102.7), is located south of Forest Glen in a very steep-sloped, mountainous region. Spawning habitat is not abundant, but juvenile steelhead habitat is good throughout the survey reach. High-gradient cascades are prevalent in the lower section. We surveyed the lower 2.4 km of the creek on 12 May 1992, and observed four steelhead redds.
Smokey Creek. Smokey Creek, a tributary to the SFTR (RKM 104.1), is located south of Forest Glen. Smokey Creek is characterized by a wide floodplain with abundant spawning habitat and large pools. We surveyed the lower 2.9 km of the creek on 13 May 1992, and observed 17 redds.
