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901. [Image] Forestry program for Oregon
This document sets forth the Board of Forestry's strategic vision for Oregon's forests for the next eight yearsCitation -
"September 8, 1999."
Citation -
903. [Image] Proceedings of second conference of engineers of the Reclamation service, with accompanying papers.
Conference was held at El Paso, Tex., November 14 to 18, 1904, and adjourned to Washington, D.C., where it was continued from January 9 to 14, 1905;Citation Citation
- Title:
- Proceedings of second conference of engineers of the Reclamation service, with accompanying papers.
- Author:
- Newell, Frederick Haynes, 1862-1932
- Year:
- 1905, 2008, 2005
Conference was held at El Paso, Tex., November 14 to 18, 1904, and adjourned to Washington, D.C., where it was continued from January 9 to 14, 1905;
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905. [Image] Monitoring of Lost River and Shortnose suckers and shoreline spawning areas in Upper Klamath Lake, 1999
Monitoring of Lost River and Shortnose Suckers at Shoreline Spawning Areas in Upper Klamath Lake, 1999 Prepared by: Rip S. Shively1 Mark F. Bautista2 Andre E. Kohler2 1 U. S. Geological Survey, Biological ...Citation Citation
- Title:
- Monitoring of Lost River and Shortnose suckers and shoreline spawning areas in Upper Klamath Lake, 1999
- Author:
- Shively, Rip S.; Bautista, Mark F.; Kohler, Andre E.
- Year:
- 1999, 2005
Monitoring of Lost River and Shortnose Suckers at Shoreline Spawning Areas in Upper Klamath Lake, 1999 Prepared by: Rip S. Shively1 Mark F. Bautista2 Andre E. Kohler2 1 U. S. Geological Survey, Biological Resources Division Klamath Falls Duty Station 6937 Washburn Way Klamath Falls, OR 97603 2 Johnson Controls World Services Inc. NERC Operation Post Office Box 270308 Fort Collins, CO 80527 Executive Summary In 1999, we sampled Lost River { Deltistes luxatus) and shortnose ( Chasmistes brevirostris) suckers from 5 April to 17 June at five shoreline spawning locations in Upper Klamath Lake ( UKL). Trammel nets were set to encompass identified spawning areas and were fished approximately 1- 1.5 hours before sunset until 3 hours after sunset or until 20 or more fish were captured. A total of 808 Lost River and 19 shortnose suckers were captured from Sucker, Silver Building, Ouxy, and Boulder springs, and Cinder Flats. The majority of Lost River suckers were captured at Cinder Flats ( 35%) and Sucker Springs ( 34%), followed by Ouxy Springs ( 16%), Silver Building Springs ( 12%), and Boulder Springs ( 3%). Males dominated the catch at all sites, but the sex ratios at Cinder Flats and Silver Building Springs were particularly skewed towards males. We recaptured 32 Lost River suckers that had been tagged during previous years sampling efforts. All of these fish, with the exception of two fish tagged at Ball Point in July, were originally tagged during the spawning season at shoreline spawning areas in UKL. This information provides further evidence that distinct stocks of Lost River suckers exist based on spawning location ( i. e., UKL and Williamson River). We also recaptured 23 Lost River suckers that were tagged in 1999 at shoreline spawning areas. Approximately half of these fish were recaptured at different locations than tagged indicating these fish were moving between spawning areas. The size offish captured at shoreline spawning areas decreased as the spawning season progressed, although the decrease in size was not as dramatic as reported in previous years. A limited number of shortnose suckers were captured at shoreline spawning areas in 1999, with a majority sampled after 1 May. Previous data for shortnose suckers at these sites is limited with respect to size, timing of spawning, sex composition, and relative numbers. Continuation of systematic sampling efforts at shoreline spawning areas will provide valuable information on the demographics and life history of Lost River and shortnose suckers utilizing these areas. Acknowledgements We thank Anita Baker, Brooke Bechen, Lani Hickey, and Tonya Wiley for assisting with sampling offish at shoreline spawning areas. Mark Buettner and Brian Peck ( U. S. Bureau of Reclamation) provided support during the early phases of our sampling as well as helpful comments on this report. We also appreciate the cooperation and support of Larry Dunsmoor ( Klamath Tribes) for identifying spawning areas, providing logistical support, and for the thoughtful review of this report. Cassandra Watson and Elizabeth Neuman produced finalized versions of tables and figures within this report and their efforts are greatly appreciated. This research was funded by the U. S. Geological Survey, Biological Resources Division through the Western Reservoirs Initiative. Introduction Severe water quality problems in Upper Klamath Lake ( UKL) have led to critical fisheries concerns for the region. Historically, UKL was eutrophic but has become hypereutrophic ( Goldman and Home 1983) presumably due to land- use practices within the basin ( USFWS 1993). As a result, the algal community has shifted to a monoculture of the blue- green algae Aphanizomemon flos- aquae and massive blooms of this species have been directly related to poor water quality episodes in UKL. The growth and decomposition of dense algal blooms in the lake frequently cause extreme water quality conditions characterized by high pH ( 9- 10.5), widely variable dissolved oxygen ( anoxic to supersaturated), and high ammonia concentrations (> 0.5 mg/ 1 unionized). In addition to water quality problems associated with A. flos- aquae, it is believed the loss of marsh habitat near the lake, timber harvest, removal of riparian vegetation, livestock grazing, and agricultural practices within the basin has contributed to hypereutrophic conditions. It is likely that these disturbances have altered the UKL ecosystem substantially enough to contribute to the near monoculture of A. flos- aquae. Investigations in 1913 documented the algal community as a diverse mix of blue- green and diatom communities, however, by the 1950' s A. flos- aquae was dominant ( USFWS 1993). The Lost River sucker ( Deltistes luxatus) and shortnose sucker ( Chasmistes brevirostris) are endemic to the Upper Klamath Basin of California and Oregon ( Moyle 1976). Declining population trends for both species were noted as early as the mid- 1960' s, however, the severities of the population declines were not evident until the mid- 1980' s. In 1988 the U. S. Fish and Wildlife Service listed both Lost River and shortnose suckers as endangered. Suspected reasons for their decline included damming of rivers, dredging and draining of marshes, water diversions, hybridization, competition and predation by exotic species, insularization of habitat, and water quality problems associated with timber harvest, removal of riparian vegetation, livestock grazing, and agricultural practices ( USFWS 1993). The U. S. Geological Survey, Biological Resources Division ( BRD) has been conducting field investigations on Lost River and shortnose suckers in UKL since 1994. The majority of these sampling efforts have focused on catching fish in UKL and the Lower Williamson River. Sampling in the Lower Williamson River focused on developing indices of relative abundance of Lost River and shortnose suckers. In 1999, Oregon State University continued sampling in the Lower Williamson River fishing trammel nets from April to August at four standardized locations. In addition to sampling efforts in the Lower Williamson River, BRD crews conducted periodic sampling at several shoreline spawning areas on the east side of UKL. This sampling was beneficial because it provided information on species composition, size, and sex ratios of suckers utilizing these areas. However, temporal changes in abundance may have been missed because consistent sampling never occurred throughout the entire spawning season ( Perkins et al, In preparation). Recently, there has been increased concern on the effects of water level management in UKL on spawning suckers. Information is needed on the timing, relative abundance, and distribution of sucker spawning in UKL to make informed decisions with respect to management of lake elevation. In 1999, we conducted systematic trammel netting surveys at Sucker, Silver Building, Ouxy, and Boulder springs and Cinder Flats along the east shore of UKL. In addition, we sampled periodically at Barkley Springs and Modoc Point to determine if suckers were utilizing these areas for spawning. This report summarizes data collected in 1999 on shoreline spawning populations of Lost River and shortnose suckers with emphasis on timing, species composition, sex ratios, and relative abundance. Methods We conducted systematic trammel netting surveys at five locations along the east shore of UKL ( Figure 1). We began sampling at Cinder Flats, Sucker, Silver Building, and Ouxy springs in early April with Boulder Springs added to the list of sampling sites on 27 April. In addition to these sites, we periodically sampled at Barkley Springs and Modoc Point ( Table 1). We attempted to sample each site twice per week although certain sites were only sampled once per week when catch rates of suckers were low ( i. e., less than 5 fish per evening). Trammel nets were fished for about 4 hours ( approximately 1- 1.5 hours before sunset until 3 hours after dark) or until we captured 20 or more fish. Nets used at individual sites varied in length from 15- 30 m, were 1.8 m tall with two outer panels ( 30cm bar mesh), an inner panel ( 3.8 cm bar mesh), a foam core float line, and a lead core bottom line. Generally, we set 1- 2 nets starting at the shoreline and extending out to encompass the perimeter of the identified spawning area. Nets were checked at approximately 1 hour intervals and captured fish were cut from the inner mesh panel and placed in a mesh cage and processed within 2 hours. Suckers were identified by species and sex, measured to the nearest mm ( fork length), inspected for tags ( both PIT and Floy tags), and examined for physical afflictions ( e. g., presence oiLernaea spp. and lamprey scars). If a sucker did not have a PIT tag, one was inserted with a hypodermic needle along the ventral surface 1- 2 cm anterior of the pelvic girdle. The catch per unit effort ( CPUE) of adult Lost River suckers was calculated for individual sampling locations for each evening sampled. Because identified spawning areas varied in size we used different length trammel nets to encompass the spawning areas. We did not attempt to standardize CPUE based on length of trammel nets used at each location. Results We sampled shoreline spawning areas from 5 April - 17 June capturing a total of 808 Lost River suckers and 19 shortnose suckers from 5 sites ( Table 1). Lost River and shortnose suckers were captured at Sucker Springs, Silver Building Springs, Ouxy Springs, and Cinder Flats, while only Lost River suckers were captured at Boulder Springs. No suckers were captured at Barkley Springs and Modoc Point ( Table 1). The majority of Lost River suckers were captured at Cinder Flats ( 35%) and Sucker Springs ( 34%; Figure 2). Males dominated the catch at all sites and were generally smaller ( mean length = 538 mm) than females captured ( mean length = 596 mm). In particular, sex ratios ( males to females) were most skewed at Cinder Flats and Silver Building Springs ( Figure 3). Large females (> 650 mm) were captured at most sites, except Boulder Springs, and the size range offish captured over time remained similar with the exception that a fewer large individuals (> 600 mm) were captured in the late sampling period ( 1 May - 17 June) as compared to the early sampling period ( 6- 30 April; Figure 4; Appendix Figure A). The catch of shortnose suckers was limited at all sites sampled. Most ( 12 of 19) of the shortnose suckers were collected at Sucker Springs, with 1- 3 fish captured at Cinder Flats, Ouxy Springs, and Silver Building Springs ( Table 1). We identified 8 males and 8 females during the sampling period and were unable to determine sex for three individuals. The mean size of shortnose suckers was 360 mm ( range 289- 528 mm) similar to data reported by Perkins et al. ( In preparation) from Sucker, Silver Building, and Ouxy springs. We observed the highest CPUE of Lost River suckers at Cinder Flats ( mean CPUE= 12.7/ h) followed by Sucker Springs ( mean CPUE= 6.0/ h), Silver Building Springs ( mean CPUE = 2.8/ h), and Ouxy Springs ( mean CPUE= 2.4/ h) ( Figure 5). On three occasions at Cinder Flats, 20 or more suckers were captured within an hour or less resulting in the termination of sampling for the evening. CPUE was calculated for sampling dates at Boulder Springs ( mean CPUE= 1.4/ h), although comparisons with other sites is not applicable because this site was not initially included in systematic sampling efforts. We did not calculate CPUE for shortnose suckers. We captured a total of 32 Lost River and 2 shortnose suckers that were tagged during previous years sampling efforts. The majority ( 96%) of these fish was originally tagged at shoreline locations ( Table 2), which is consistent with historical recapture data ( Appendix Table A). Two Lost River suckers were originally tagged at Ball Point in UKL in July, after the spawning season. In addition, most Lost River suckers were recaptured before 1 May, including 15 fish that were collected at Sucker Springs during two sampling occasions in March ( Figure 6). We also recaptured a total of 21 Lost River suckers that were tagged in 1999 at shoreline spawning areas. Approximately half of these fish were recaptured at different areas than where they were tagged, indicating that some suckers are moving between spawning areas within the season ( Table 3). Discussion Our sampling indicated the spawning period for Lost River suckers lasted from mid- March through the beginning of June at shoreline spawning areas in 1999. The catch of Lost River suckers was dominated by males at all sites sampled, particularly at Cinder Flats and Silver Building Springs. Perkins et al., ( In preparation) reported skewed sex ratios at shoreline spawning locations following the fish kills that occurred in UKL from 1995- 1997. However, the ratios we observed were considerably higher than those reported by Perkins et al., ( In preparation). At this time we are unable to determine the reason for the sex ratios observed. It is possible that males remain longer at the spawning areas than females making them more vulnerable to capture. Perkins et al., ( In preparation) observed spawning acts and reported that males remained near the actual site where spawning occurs while females move onto the spawning site only when ready to spawn. We captured 23 Lost River suckers twice in 1999 and all but one of these fish were males. However, it is difficult to determine if this percentage is due to males remaining at these sites longer than females or a reflection of the existing sex ratios. Another possible explanation could be the large numbers of males in the catch are from the 1991- 1993 year classes and females from these year classes have yet to be recruited into the adult population. The majority of males captured ( 81%) were between 475 - 574 mm. Age and growth information from Lost River suckers collected during the 1996- 1997 fish kills indicate these fish would be between 5- 9 years old ( USGS, BRD, 10 unpublished data). Perkins et al., ( In preparation) reported that male Lost River suckers migrating up the Williamson River begin to be recruited into the adult population starting at age 4+, while females did not begin to mature until age 7+ . These data were based on examining length frequency distributions and noting when fish from the 1991 year class, which is presumed to be a strong year class, began showing up in trammel net catches. Fish from the 1991 year class would have been age 8+ in 1999. Buettner and Scoppetone ( 1990) examined opercles from Lost River suckers collected during the 1986 fish kill in UKL and reported that individuals matured between 6- 14 years of age with the peak being 9 years. It is possible that in the next few years more females from the 1991- 93 year classes will be recruited into the adult population spawning at shoreline areas. Our data provides additional evidence that distinct stocks of Lost River suckers may exist based on fidelity to spawning area. Of the 32 suckers we recaptured from previous years sampling efforts, all but two were originally tagged at shoreline spawning locations. The two fish that were not originally tagged at shoreline spawning locations were captured at Ball Point in July and were not presumed to be spawning in this location. Perkins et al. ( In preparation) reported that of 316 Lost River and 11 shortnose suckers recaptured at shoreline spawning areas all were originally tagged at shoreline spawning locations. Continuation of systematic sampling at both shoreline spawning areas and the Williamson and Sprague rivers will continue to provide information on potential separation of spawning populations. The majority of recaptured fish were tagged during the first half of our sampling efforts including 13 fish that were recaptured on 25 March while sampling with Larry Dunsmoor of the Klamath Tribes. Historically, the majority of sampling effort at 11 shoreline spawning locations occurred prior to 1 May, which may explain why most recaptures were collected during the early part of our sampling period. In fiiture years, we plan to continue systematic sampling through June to determine if temporal aspects of spawning remain consistent between years. The size offish captured at shoreline spawning areas decreased as the spawning season progressed, particularly near the end of our sampling period, although the decrease was not as dramatic as reported by Perkins et al., ( In preparation). It is possible that individual timing of Lost River sucker spawning is affected by size. Scoppettone et al., ( 1986) observed that smaller, younger cui- ui ( Chasmistes cujus) at Pyramid Lake spawned at the end of the spawning season. We believe further investigation is needed to determine if differences in spawning timing among individuals is due to size or related to stock differences. A limited number of shortnose suckers were captured in 1999. Sampling continued well into June and was sufficient to detect spawning concentrations of shortnose suckers at these sites. Based on previous sampling conducted at shoreline spawning areas, there appears to be a decreasing trend in the number of shortnose suckers captured at these sites ( Perkins, et al., In preparation). Our sampling efforts at shoreline spawning areas on the east side of UKL represents the first time these areas have been systematically sampled during the spawning season. Continuation of systematic sampling at these areas is important to provide information on species composition, timing and duration of spawning, fidelity to spawning areas, sex ratios, size distribution, and relative abundance. How these 12 population characteristics change over time will also provide important insights into the population stability of Lost River and shortnose suckers in UKL. 13 Literature Cited Buettner, M. And G. Scoppettone. 1990. Life history status of catostomids in Upper Klamath Lake, Oregon. U. S. F. W. S. Completion Report. 108 pp. Goldman, C. R. and A. J. Home. 1983. Limnology. McGraw Hill, New York. Moyle, P. B. 1976. Inland fishes of California. University of California Press, Berkeley, CA. Perkins, D. L., G. G. Scoppettone, and M. Buettner. In preparation. Reproductive biology and demographics of endangered Lost River and shortnose suckers in Upper Klamath Lake, Oregon. U. S. Fish and Wildlife Service. 1993. Lost River ( Deltistes luxatus) and shortnose ( Chasmistes brevirostris) sucker recovery plan. Portland, Oregon. 108 pp. 14 Table 1. Summary of the shoreline locations sampled in Upper Klamath Lake and the number of Lost River ( LRS) and shortnose ( SNS) suckers captured in 1999. Sampling Dates Sampled Number of days Number of LRS Number of SNS Location ( range) Sampled Captured Captured Barkley Springs 4/ 5- 4/ 27 4 0 0 11 21 0 19 284 2 4 0 0 20 129 3 19 100 2 Sucker Springs 4/ 5- 6/ 17 20 274 13 Total 808 20 Boulder Springs Cinder Flats Modoc Point Ouxy Springs Silver Bldg. Springs 4/ 27- 4/ 6- 4/ 13- 4/ 6- 4/ 5- 6/ 17 6/ 17 4/ 21 6/ 17 6/ 17 15 Table 2. Summary of the number of Lost River suckers recaptured from previous years sampling efforts at shoreline spawning locations in Upper Klamath Lake, 1999. Site Originally Captured Boulder Springs Cinder Flats Ouxy Springs Silver Bldg. Springs Sucker Springs Ball Point Total Boulder Springs 0 0 0 0 0 0 0 Site Cinder Flats 0 1 0 0 4 2 7 Recaptured Ouxy Springs 0 0 0 1 1 0 2 in 1999 Silver Bldg. Springs 0 0 0 1 0 0 1 Sucker Springs 0 0 1 2 19 0 22 16 Table 3. Summary of the number of Lost River suckers recaptured at shoreline locations in Upper Klamath Lake originally tagged in 1999. Site Originally Captured in 1999 Boulder Springs Cinder Flats Ouxy Springs Silver Bldg. Springs Sucker Springs Total Boulder Springs 0 0 0 0 0 0 Site Cinder Flats 0 3 1 3 1 8 Recaptured Ouxy Springs 0 1 0 0 3 4 in 1999 Silver Bldg. Springs 0 0 1 1 0 2 Sucker Springs 0 2 0 1 6 9 17 1. Sucker Springs 2. Silver Building Springs 3. Ouxy Springs 4. Cinder Flats 5. Boulder Springs Figure 1. Map of Upper Klamath and Agency Lakes showing major tributaries and shoreline spawning areas sampled in 1999. 18 o I 50 45 40 35 30 25 20 15 10 5 0 BOULDER SPRINGS 50 45 40 35 30 25 20 15 10 5 0 D LRS Male • LRS Female * No Fish Jtt * * * * * * OUXY SPRINGS D LRS Male • LRS Female * No Fish 50 45 40 35 30 25 20 15 10 5 0 CINDER FLATS D LRS Unknow n _ r i • LRS Male • i_ r\ o remaie ic No Fish EII1IJ n „ * * * * 50 45 40 35 30 25 20 15 10 5 0 > SILVER BUILDING SPRINGS • LRS Unknow n • LRS Male • LRS Female * No Fish D n n p » * * * * * SUCKER SPRINGS ALL AREAS COMBINED • LRS Unknown D LRS Male • LRS Female • LRS Unknow n • LRS Male • LRS Female / / / / / / Figure 2. Summary of the number and sex of Lost River Suckers ( LRS) captured at shoreline spawning areas in Upper Klamath Lake, 1999 sampling. LRS unknown refers to captured individuals in which sex could not be determined. 19 70% -, 60% 50% 40% - 30% - 20% - 10% 0% CINDER FLATS _ o_ n= 283 9.1 : 1 8C O in io in om CD o i n 70% -, 60% - 50% - 40% - 30% - 20% - 10% - 0% - BOULDER SPRINGS y n 11 7 6 2 n= 21 9.5: 1 • g si n 8 CD omr o in oo § 70% 60% 50% 40% 30% 20% 10% 0% OUXY SPRINGS om CN oi n co o ini o in in SUCKER SPRINGS 70% -, 60% - 50% - 40% - 30% - 20% - 10% - 0% - n= 129 4.1 : 0 • _ o in CD omh omoo n= 273 3.5: 1 U • - - sC O oi n oi nm om o i n 00 70% 60% 50% 40% 30% 20% - 10% 0% SILVER BUILDING SPRINGS 70% 60% - 50% - 40% 30% 20% 10% - 0% 8 CM ALL SITES 8 CO JL 8 8 i n n= 99 8.1 : 1 • H „ - in in in CD h- 00 n= 805 5.3: 1 _ D • Male • Female 8 C N O O O O O O O O O O O i n o m oin i nin oCDi nCDo i n o i nco Fork length Figure 3. Length frequency histogram of male and female Lost River suckers ( LRS) captured at shore-line spawning areas in Upper Klamath Lake, 1999. The total number of LRS captured in 1999 and ratio of males to females are presented in the upper right hand corner of each graph. 20 E QJ D 160 i 140 120 100 80 60 40 20 0 A) 1999 LR Length Frequency ( 3/ 18/ 99- 4/ 30/ 99) DMale • Female • male = 457 xM = 541.4 i siaev - jo. y female = 60 xF = 611.9 stdev = 77.2 (—| Qy O ^ D 160 140 120 100 80 60 40 20 # 4? B) o - I— # $ # C) # # $ # 1999 LR Length Frequency ( 5/ 1/ 99 - 6/ 8/ 99) DMale • Female male = 219 xM = 531.4 5> lUeV — H 1 , , — i remaie = bB xF = 582 8 stdev = 68.1 • y . _ _ # ^ # # # # # # # ^ 1999 SN Length Frequency ( 4/ 30/ 99 - 5/ 30/ 99) 1 U 14 - 12 - 10 s p. A 2 0 - , Dmale • female y y • l i y n male = 8 xM = 363 stdev - 29.7 fpryiolp — ft xF = 357.1 stdev = 35.5 Forklength ( mm) Figure 4. Length frequency for Lost River ( LRS) and shortnose ( SNS) suckers captured at shoreline spawning areas in Upper Klamath Lake, 1999. Graphs represent A) LRS caught from March 19- April 30, 1999, B) LRS caught from May 1- June 8, 1999, and C) SNS caught from April 30- May 30, 1999 ( all SNS sampling days were combined due to limited SNS numbers). Four LRS with unknown gender were not included in the graph, two were caught before May 1st, and two after May 1st. Three SNS with unknown gender were not included in the graph. 21 BOULDER SPRINGS 20 i 18 16 - I 14 12 10 8 6 4 2 0 O) O) O) 0 ) 0 ) 0 ) 0 ) 0 ) in CM O) $ § I co o L? 5 LO O) O) O) g> g> g> o r^ •<*• n ^ CN CD CD CD 45 40 - 35 30 25 20 15 10 - 5 0 CINDER FLATS 0 ) 0 ) OO - f - r in in 0 ) 0 ) 0 ) C D C D C D 1 sw 20 18 16- 14- 12 - 10 8 6 4 OUXYSPRNGS Jl 0 ) 0 ) 0 ) 0 ) OO 0 ) 0 ) 0 ) C N I O C D O) O) O) O) Q < o z: ? z in CD CD 20- 18 - 16 14 - 12 - 10 - 8 6 4 - 2 - 0 - SILVER BUILDING SPRINGS ii , II p l, « u u •———,—— O) O) O) 0 ) 0 ) 0 ) in CN O) T- CM CM O) O) O) O) O) O) CO O h » - in O) O) O) ill CD CD CD SUCKER SPRINGS ALL SITES Figure 5. Summary of catch per unit effort ( CPUE) of Lost River suckers at shoreline spawning areas in Upper Klamath Lake, 1999. Note change in scale for the Cinder Flats and the All Sites graphs. 22 BOULDER SPRINGS 14 12 10 8 -| 6 4 2 0 n= 0 0 ) 0 ) 0 ) 0 ) 0 ) 0 ) 0 ) O) CD CN O) CD CO O T - C\| ^ ^ T- CNJ CO CO CO ^" ^" ^" OUXY SPRINGS 1 C D n= 2 14 1 8 4 2^ 0 oo S ^ ^ SUCKER SPRINGS ^ £ j CNJ in in to n= 22 - U-CD CO O j - CM CO 1 C D 14 12 -\ 10 8 -] 6 4 2 - 0 CINDER FLATS n= 7 LJl 0 ) 0 ) 0 ) 0 ) 0 ) T^ Cr^ N ^? ^ T- 14 12 10 - 8 6 4 - 2 0 SILVER BUILDING SPRINGS Tt x- 00 - CN CN in in in n= 1 0 ) 0 ) 0 ) 0 ) 0 ) 0 ) 0 ) 0 ) 0 ) 0 ) 0 ) 0 ) O) CD CN O> CD CO ^ CJ ^ ^ ^ CN co co ^ j- "< t ALL SITES O) O) O) O) O) O) in in in n= 32 I 0 0) in in in Figure 6. Summary of the number of Lost River suckers recaptured at shoreline spawning areas, Upper Klamath Lake, 1999. Recaptured fish were originally tagged betweeen 1988- 1998. 23 Appendix Table A. Summary of recapture data for Lost River Suckers in the Upper Klamath Lake Basin from 1985- 1999. Sampling was generally conducted from March- July of each year, although the emphasis in sampling was during the spawning period. Recapture data includes fish that were tagged with Floy and PIT tags. Site Last Recaptured Site Originally Captured Cinder Flats Ouxy Springs Silver Bldg. Springs Sucker Springs Williamson River Sprague River Upper Lake Middle Lake Total Cinder Flats 1 0 0 4 0 0 2 0 7 Ouxy Springs 0 1 1 1 0 0 0 0 3 Silver Bldg. Springs 0 0 1 6 0 0 0 0 7 Sucker Springs 0 0 6 288 4 0 0 0 298 Williamson River 0 0 0 1 6 3 0 0 10 Sprague River 0 0 0 0 1 13 1 0 15 Upper Lake 0 0 0 0 0 0 0 0 0 Middle Lake 0 0 1 0 1 0 0 0 2 Total 1 1 9 300 12 16 3 0 342 Appendix Table B. Summary of recapture data for shortnose suckers in the Upper Klamath Lake Basin from 1985- 1999. Sampling was generally conducted from March- July of each year, although the emphasis in sampling was during the spawning period. Recapture data includes fish that were tagged with Floy and PIT tags. Site Last Recaptured Site Originally Captured Ouxy Springs Silver Bldg. Springs Sucker Springs Williamson River Sprague River Lower Lake Middle Lake Total Ouxy Springs 1 0 0 0 0 0 0 1 Silver Bldg. Springs 0 0 0 0 0 0 0 0 Sucker Springs 1 0 0 0 0 0 0 1 Williamson River 0 0 0 4 0 0 0 4 Sprague River 0 0 0 2 3 0 0 5 Lower Lake 0 0 0 0 0 0 0 0 Middle Lake 0 0 0 1 2 0 5 8 Upper Lake 0 0 0 0 0 0 0 0 Reeder Road Bridge 0 0 0 0 0 0 1 1 Total 2 0 0 7 5 0 6 20 25 5 2iu5 Appendix Figure A. Summary of the size range of Lost River suckers captured at shoreline sampling areas in Upper Klamath Lake, 1999, by date sampled.
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906. [Image] The Endangered Species Act and the National Research Council's interim judgment in Klamath Basin
The controversial 2001 U.S. Fish and Wildlife Service water allocation decision in the Klamath Basin has been portrayed as an example of scientific guesswork operating under a flawed Endangered Species ...Citation Citation
- Title:
- The Endangered Species Act and the National Research Council's interim judgment in Klamath Basin
- Author:
- Cooperman, Michael S. ; Markle, Douglas F.
- Year:
- 2002, 2005
The controversial 2001 U.S. Fish and Wildlife Service water allocation decision in the Klamath Basin has been portrayed as an example of scientific guesswork operating under a flawed Endangered Species Act. This conclusion has been based on an interim National Research Council report, quickly prepared in late fall, 2001. We have reviewed several iterations of the NRC Interim Report as well as all Biological Opinions and management documents related to Klamath Basin suckers and provide an overview. The 2001 Biological Opinion and the Interim Report illustrate the lack of consensus typical of scientists in the early stages of exploring a complex system. Unfortunately, the decision created hardship for a small group of people and the lack of scientific consensus has politicized the debate. Politicians have assumed that the Interim Report has primacy in the scientific debate when, in fact, its speedy construction contributed to multiple errors that detract from its scientific usefulness. The NRC Interim Report has, instead, primarily served to deflect debate away from the needs of listed fishes to one about shortcomings in the Endangered Species Act. Although the process of science has been served by both the 2001 Biological Opinion and the Interim Report, both have shortcomings, and we see no justification for either side labeling the other's decisions or conclusions as "not sound science."
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907. [Image] The trout and salmon of the Pacific coast
This article is an overview of the variety of trout and salmon that are found in Oregon and Washington states.Citation -
908. [Image] Natural flow of the upper Klamath River
Executive Summary Executive Summary This report presents details of the investigation and results in estimating the natural flow of the upper Klamath River at Keno, Oregon. The area investigated includes ...Citation Citation
- Title:
- Natural flow of the upper Klamath River
- Author:
- United States. Bureau of Reclamation. Klamath Basin Area Office
- Year:
- 2005, 2008
Executive Summary Executive Summary This report presents details of the investigation and results in estimating the natural flow of the upper Klamath River at Keno, Oregon. The area investigated includes the Klamath River Basin above Keno, Oregon, primarily in Klamath County, with some areas of Siskiyou and Modoc Counties in California. The study area includes the Sprague, Williamson, and Wood River basins, as well as Upper Klamath and Lower Klamath Lakes. Objectives The current purpose of this study is to provide an estimate of the monthly natural flows in the upper Klamath River at Keno. This estimate of the natural flow represents typical flow without agricultural development in the Upper Klamath River Basin, including its tributaries. Study Approach This study used a water budget approach to assess the agricultural depletions and alterations to the natural flow. The approach was to evaluate the changes of agriculture from predevelopment conditions, estimate the effects of these changes, and restore the water budget to natural conditions by reversing the effects of agricultural development. Records used in this empirical assessment were derived from both stream gaging flow histories and from climatological records for stations within and adjacent to the study area. Water Budget Description The water budget assessment of the watershed as a natural system includes an evaluation of hydrological changes related to agricultural development above the Keno gage. The water budget assessment includes: ? Natural inflow from the Sprague, Williamson, and Wood Rivers to Upper Klamath Lake ? Predevelopment evapotranspiration losses from marshes surrounding Upper Klamath Lake ? Predevelopment evaporation losses of the Upper Klamath Lake ? Natural flow at the outlet of Upper Klamath Lake into the Link River at Klamath Falls ? Resulting natural flow at Keno The processes developed in the water budget to evaluate the natural outflow of Upper Klamath Lake accounts for factors related to water resources developments XI Natural Flow of the Upper Klamath River in the watershed that have affected inflow to the lake, and for losses due to natural condition of the lake. The water budget assessment of the watershed as a natural system includes an evaluation of hydrological changes related to agricultural development above the Keno gage. The results of the water budget assessment are given as average annual flows for two important stream gages, one located on the Link River at Klamath Falls and the other on the Klamath River at Keno. Evaluation of Predevelopment Conditions An evaluation of predevelopment conditions included an evaluation of changes to Upper Klamath Lake, agricultural developments in the Wood River, Sprague River, and Williamson River watersheds. Several basic elements were considered in this study: ? How had development changed the system ? Was information available about conditions before the changes occurred ? Were data available to assist in estimating changes to the natural system Evaluation of Current Conditions Period of Record The period of record considered in this investigation is the 52 years from 1949 to 2000. This period of record was chosen because hydrologic and climatological data were limited for the pre-1949 period and data beyond 2000 were not available when the study began. The water year convention (October through September) is used in this report. Crop and Marshland Evapotranspiration Analysis The modified Blaney-Criddle method was used to determine potential net evapotranspiration (ET) from crops, marshlands, and riparian zones. The method is empirical and the calculated values were adjusted based on other recent study findings and water limiting considerations. To estimate net ET water consumption by this method requires the following data: ? Location of irrigated lands, marshlands, and riparian zones ? Types of crops and number of acres for each crop ? Types and acreages of marshland and riparian vegetation, both existing and predevelopment ? Monthly precipitation and monthly average temperature for the period of record for each area Methods to Estimate Natural Flows Natural streamflow development included adjustment of gaged streamflow to natural flow, restoration of missing streamflow and climate data, making natural streamflow estimates in ungaged watersheds, assessing groundwater XII Executive Summary contributions, and estimating transit losses. Not all of these procedures were appropriate or possible in all subbasins of the study area. Records of historic flow may be adjusted to natural flow using crop net consumptive use and marshland evapotranspiration: natural flow = gaged flow + crop net consumptive use - reclaimed natural marshland net evapotranspiration Correlation analysis was used to restore missing values from monthly-value data records used in this study. The method is different from linear least-squares regression estimation. Data records used in this study include precipitation and average temperature histories, in addition to hydrologic records of streamflow and lake stage. Also, natural streamflow histories are required in ungaged watersheds to assess the natural inflow to Upper Klamath Lake. Sparse monthly flow records for streams heading on the east flank of the Cascades and flowing into the Wood River Valley or Pelican Bay area of Upper Klamath Lake required estimation techniques that used gaged histories from nearby river basins. These data were evaluated in statistical applications to yield natural flow estimates for these ungaged portions of the Klamath Basin. In a similar vein, groundwater contributions required temporal adjustments attributable to the climate signature evident in longer term records for similar groundwater discharges in neighboring watersheds. Transit losses for both surface water and groundwater contributions were also estimated in this study. Natural Lake Simulations Implementation of a water budget for Upper Klamath Lake required developing information about (1) the storage and inundation surface area characteristics of the lake, and (2) the discharge characteristics at the outflow point of the lake. These characteristics were evaluated in relation to the elevation, or stage, of the water surface of the lake. Additionally, discharge from the lake was also related to the stage. Estimating the outflow of a natural lake is accomplished using a water budget approach. A monthly summation of all elements in the water budget may be stated by the general form of the hydrologic equation: i = o + As where i = inflow to the lake o = outflow from the lake and As = change in storage of the lake XIII Natural Flow of the Upper Klamath River For Upper Klamath Lake, the month-to-month water budget accounts for natural inflow, storage of water within each lake, resulting estimated lake stage, and discharge from each lake. In addition, open water surface evaporation and groundwater discharge to the lake from the regional aquifer were estimated. The water budget assessment was designed to simulate the lake as a natural water body. Materials and Data Researched and Used Data Sources Records used in this analysis were derived from both stream gaging flow histories and from climatological records for stations within and adjacent to the study area. Information was also developed from published reports, file documents, and maps. Supporting information included documents from: ? Archives of the Bureau of Reclamation Klamath Basin Area Office ? Numerous U.S. Geological Survey (USGS) Water Supply Papers regarding stream gaging records ? Compact disk databases containing digital records of gaged flow, lake stage records, and meteorological data Anecdotal items from newspaper articles or clipped from magazines were also reviewed. These sources consisted of narratives of past events or conditions, transcripts of interviews, newspaper accounts, books, diaries, and historical journals. These provided an impression of predevelopment conditions that can be compared to the empirical and scientific information gleaned from other sources. Other reviewed materials included unpublished and out-of-print scientific reports, historical maps, letters, books, journals, and photographs. Modeling Tools Results of the water budget assessment were accomplished using Excel?, a sophisticated spreadsheet available in the Microsoft Office for Windows software package. This model was chosen over other models because this study is unique. The computational modules built as the study developed represent a custom application of Excel? to the solution of estimating the natural flow conditions in the Upper Klamath River Basin. Klamath River at Keno Gaging Station For the simulation period, 1949 to 2000, the water balance for the Upper Klamath River Basin at Keno is described below. The natural outflow (discharge) from Upper Klamath Lake at Link River was computed in the water balance. Discharge at Keno was then calculated using a correlation relationship developed between historic measured Link River and Keno flows. Table S-l presents the estimated water balance and outflow developed for the Link River and Keno gages. XIV Executive Summary Table S-1. Estimated inflow and outflow developed for Link River and Keno gages Upper Klamath Lake Acre-feet Average annual natural inflow Average annual natural net loss 1,605,000 210,000 Resulting average annual natural outflow 1,395,000 Link River to Keno Average annual natural inflow 1,485,000 Resulting average annual natural outflow at Keno gage 1,306,000 Other Factors Considered The focus of this study is agricultural development in the Upper Klamath River Basin and its effects on natural flow conditions. Other watershed factors have changed since predevelopment. Some of these factors were considered, but are unaccounted-for in the assessment, such as changes in forest conditions or an extension of the flow histories before 1949. Model Review and Sensitivity Analysis Although this study uses best available hydrologic methods and data to either measure or estimate all inflows and outflows to the system, additional concerns have arisen in completing the work. Relationships regarding the significance of uncertainty are likely to be spatially and temporally variable. The key factor is the relative importance of each module in the transit losses suffered by inflows to the natural system. The significance of these influences to model sensitivity is related to time of year or length of time over which flows are evaluated. Model sensitivity is related to uncertainty in data regarding the most significant transit losses; namely, marsh evapotranspiration and open water evaporation. The natural flows developed at Keno are realized, in part, through a statistical rule based model rather than a physically based model. This construct within the model is for the segment from the Link River gage below Upper Klamath Lake, to the Keno gage below Lower Klamath Lake. Thus, sensitivity in testing the spatial and temporal variables within the Link River to Keno reach that affect the flow at Keno is problematic. xv Natural Flow of the Upper Klamath River Summary Development of the natural flows at the Keno gage was accomplished using a spreadsheet modeling approach to resolve the water budget for the Upper Klamath River Basin under undeveloped watershed conditions. The resulting flow duration for simulated natural average monthly flows for Keno gage are described in Table S-2. The percentiles represent the flow exceedence ranges in monthly natural flow estimates at Keno solely due to record length. These percentiles are estimates for modeled baseline conditions and do not reflect data uncertainties for possible changes in evaporation, evapotranspiration, or other factors. Table S-2. Summary of simulated monthly flows at Keno in cfs % Time <= Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sept Annual % Time >= 10 648 1088 1216 1408 1647 1577 1670 1408 1168 631 520 560 1188 90 20 769 1159 1352 1472 1767 1689 2017 1721 1358 822 578 616 1429 80 30 857 1255 1453 1667 1925 1907 2125 2051 1664 964 706 720 1528 70 40 974 1342 1625 1845 2016 2040 2477 2280 1890 1228 767 746 1607 60 50 1033 1455 1698 1964 2343 2133 2595 2649 2039 1349 873 854 1773 50 60 1131 1523 1803 2072 2410 2360 3009 2827 2388 1478 998 955 1903 40 70 1224 1576 1984 2196 2615 2703 3146 3131 2657 1706 1154 1049 2169 30 80 1304 1739 2049 2399 2829 3115 3615 3385 3104 2210 1351 1210 2347 20 90 1488 1815 2319 2659 3294 3367 3877 3707 3460 2923 1684 1412 2511 10 A simplified flowchart depicting the overall sources of included inflow and outflow variables has been completed as figure S-l, with average annual values shown from each source. XVI
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Public Review Draft 4- 27- 05 Conservation Plan Miller Lake Lamprey, Lampetra ( Entosphenus) minima April, 2005 Executive summary - The Miller Lake Lamprey was believed extinct after a chemical treatment in ...
Citation Citation
- Title:
- Conservation plan, Miller Lake lamprey, Lampetra (Entosphenus) minima : April, 2005
- Author:
- U.S. Fish and Wildlife Service
- Year:
- 2005
Public Review Draft 4- 27- 05 Conservation Plan Miller Lake Lamprey, Lampetra ( Entosphenus) minima April, 2005 Executive summary - The Miller Lake Lamprey was believed extinct after a chemical treatment in 1958, targeting lamprey and tui chub, extirpated both from Miller Lake. The lamprey population was later recognized to be a distinct species, Lampetra minima ( Bond and Kan 1973). It was the smallest lamprey species in the world ( maturing at less than 4 in), and at that time was known only from Miller Lake, where it was extinct In 1992, a small lamprey caught in the Upper Williamson River was identified as a Miller Lake Lamprey, and subsequent investigations have identified six local populations of this lamprey in two small subdrainages of the Upper Klamath Basin. Management strategies to preserve this species include: conserving appropriate habitat conditions and availability within the natural range of the Miller Lake Lamprey, addressing potential impacts from stocking streams with hatchery fish, reducing entrainment, and establishing connectivity within and between local populations. A man- made barrier built in 1959 still exists on Miller Creek. Originally created to prevent the re- establishment of lamprey in Miller Lake after the chemical treatment, the barrier currently prevents natural dispersal of the Miller Creek population and re- colonization of both extensive habitat in upper Miller Creek and Miller Lake itself. Removal of the barrier, which is in disrepair but continues to exclude lamprey, is feasible and will eliminate the only man- made feature obstructing natural connectivity within the Miller Lake drainage, the species' type locality. This conservation plan is intended to provide guidance for management actions and conservation of the Miller Lake Lamprey. Introduction lhe Miller Lake Lamprey, Lampetra { Entosphenus) minima, is the worlds smallest predatory lamprey, reaching a size of only 3- 6", and is endemic to the Klamath Basin ( Bond and Kan 1973, Gill et al. 2003, Lorion et al. 2000). It is also one of the few species to have " recovered" from extinction. Miller Lake was chemically treated with toxaphene by the Oregon Game Commission on September 16,1958 to eliminate Tui Chub ( Siphateles bicolor) and a population of unidentified lamprey ( Gerlach 1958, Gerlach and Borovicka 1964). The lamprey in Miller Lake was later discovered to have been a unique species, apparently restricted in range to the Miller Lake drainage ( a small, disjunct tributary to the Upper Williamson River), and was scientifically described by Bond and Kan ( 1973) fifteen years subsequent to its presumed extirpation. Public Review Draft 4- 27- 05 Although there appear to be no immediate threats to the Miller Lake Lamprey ( Kostow 2002), the species is of considerable conservation concern due to: 1) its relatively limited range in two small sub drainages of the Klamath Basin, 2) its continued absence in the ecologically unique setting of Miller Lake ( type locality) and 3) its evolutionary distinctiveness as the smallest known predatory lamprey in the world, maturing at less than four inches. Life History Distribution - The Miller Lake Lamprey is currently known from only two small sub- drainages of the Upper Klamath Basin, the upper Williamson River and the upper Sycan River above Sycan Marsh ( Lorion et al. 2000). The upper Williamson River contains four known populations ( Miller Creek, Jack Creek, Klamath Marsh, and mainstem Williamson River above the marsh). Miller Creek, which drains Miller Lake, is within the upper Williamson Watershed, but it goes sub- surface in the pumice soils and does not reach the Klamath Marsh or Williamson River. Miller Lake has presumably been isolated from the rest of the drainage since the eruption of Mt. Mazama ( Crater Lake) over 6,000 years ago. Jack Creek, a small northern tributary to the upper Williamson River, is also generally disjunct from the mainstem Williamson River due to low, intermittent surface flows in its lower reaches. The Upper Sycan drainage ( a northern tributary of the Sprague River) contains two principal populations, Long Creek drainage and the upper Sycan River drainage above Sycan Marsh. Lamprey have been documented in Coyote Creek and Shake Creek above Sycan Marsh by Nature Conservancy. Lamprey in Shake Creek have not been identified to species. Geographic Variability - In general, individuals from the modern Williamson and Sycan sub-drainages are morphologically similar ( Lorion et al. 2000). However, there are indications of geographic differences between populations. The Sycan populations exhibit significantly higher variability in the number of bicuspid posterial teeth, and the Miller Creek population generally tend to be darker on their ventral surface. Specimens from the original Miller Lake population ( pre- 1958) had, on average, fewer anterial teeth. They also tended to have larger eyes and oral disks relative to total length when compared to modern populations; however, this appears to be due to their slightly smaller size. The available genetic information also indicates that there are geographic differences in the mitochondrial genome ( mtDNA) between Sycan ( Sprague) and Williamson lamprey populations, with one haplotype found only in the Upper Sycan and another limited to lamprey populations in the Sprague River drainage ( Lorion et al. 2000). Continued genetic work on the Klamath lamprey fauna, examining additional genes, indicates that the population of lamprey in Miller Creek may be genetically different than both the other upper Williamson and Sycan populations ( Docker pers. com. 2004). Habitat - Miller Lake Lampreys currently occupy relatively cool, clear streams ( Gunckel and Reid 2004, Kan and Bond 1981, Lorion et al. 2000, Reid pers. com. 2004). Adults are generally associated with structural cover, including loose rocks and woody debris. In lower Miller Creek, where rocky habitat is limited, adult lampreys were consistently found in woody debris jams and even under seat boards from an old outhouse that had fallen into the creek ( Reid pers. obs. 1998). Ammocoetes ( a larval stage lasting about 5 years) live in the substrate and are generally Public Review Draft 4- 27- 05 associated with depositional environments. In streams, ammocoetes are frequently found in silty backwater areas, low energy stream edges, and in pool eddies where leaf litter and other organics ( including adult lamprey carcasses) tend to accumulate. At night ammocoetes may move into the water column to disperse downstream or into more favorable habitat. In Miller Lake ammocoetes were found in organic detritus all along the shoreline but rarely in the extremely cold tributaries flowing into the lake ( Kan and Bond 1981). Recent extensive collections of Pacific Lamprey ammocoetes along the coast indicate that ammocoetes do not occupy otherwise apparently suitable sediments if the upper layer is poorly oxygenated ( Reid and Goodman pers. obs. 2004). Reproduction - Miller Lake Lampreys spawn in shallow redds in clean gravels and sand, which are moved out of the redd by lamprey sucking onto small rocks and actively moving them out of the way ( Markle pers. com. 2004, Reid pers. com. 2004). In streams, redds are generally made in shallow water, often at the tail of a pool or run, and are roughly 10 cm in diameter and a few centimeters deep. In Miller Lake, lampreys were observed spawning in water as deep as 20 feet ( Cochrun 1951b, Kan and Bond 1981). Males attach to the female's head and wrap around her body, aligning genitals and allowing fertilization of the eggs as they emerge. Eggs are heavier than water and are mixed into the bottom of the redd by spawning actions. Kan and Bond ( 1981) found that female lampreys from Miller Lake contained an average of about 600 eggs. Time to hatching is not known, but is probably on the order of a few weeks. Larvae ( ammocoetes) emerge at about 8 mm and move into fine sediments. Adults die after spawning. Feeding - Miller Lake Lampreys feed on fish only as adults. Ammocoetes have no eyes or teeth and are purely filter feeders, burrowing in the sediment and feeding on suspended microorganisms and algae. The ammocoete phase lasts about five years, during which time the ammocoetes grow to around 150 mm. After transformation, adults enter a predatory phase before spawning that generally lasts for less than a year ( from transformation in the summer/ fall to spawning in summer of the following year). Adults feed primarily on flesh that is gouged and rasped out of a small wound (<= 11 mm) under the sucking disk ( Cochran 1994, Kan and Bond 1981). Adults apparently show little selectivity for prey. The adult lampreys in Miller Lake historically fed on both tui chubs and available salmonids ( rainbow, brook and juvenile brown trout) in Miller Lake ( Kan and Bond 1981). They also scavenged dead tui chubs and trout, as well as cannibalizing other lampreys. In Miller Creek, most recent observations found occasional lamprey wounds on brook trout, which were the most abundant species in the creek, but it is probable that lampreys also feed on both rainbows and young brown trout in the creek ( S. Reid pers. obs. 1998). In Jack Creek lampreys feed on speckled dace, the only other fish present in the stream, and in the Upper Sycan they feed on both trout and dace. Unlike other predatory lampreys, but similar to non- feeding brook lampreys, adult Miller Lake Lampreys loose body length and mass between the time they transform and actual spawning, indicating that energetic needs and gonadal development are not compensated for by the amount of food they consume ( Hubbs 1971, Kan and Bond 1981, Lorion et al. 2000). Lamprey / Trout Interaction - Although there have been no direct studies of the ecological interaction between lampreys and trout in the Klamath Basin, it is notable that healthy trout and lamprey populations coexist throughout the basin. Lampreys certainly prey on trout, and both adult lampreys and ammocoetes may represent a significant food resource to piscivorous adult Public Review Draft 4- 27- 05 trout. Native redband trout co- exist with much larger predatory lampreys (" Klamath Lake Lamprey", Lampetra { Entosphenus) sp., and Klamath River Lamprey, L. ( E.) similis) in Upper Klamath Lake. A large percentage of the trophy redband trout in Upper Klamath Lake, as well as both redband and brown trout in the Wood and Williamson Rivers, exhibit recent or healed lamprey scars. In smaller streams where Miller Lake Lampreys ( length 3- 6 in) co- exist with native and introduced trout ( redband, bull, brook and brown trout), there appears to be little impact to adult trout, and local fishermen are rarely even aware of the presence of the lamprey ( S. Reid, pers. comm. 2004, R. Smith, pers. comm. 2004). Surveys by USFWS and USFS in 1998- 1999 found that very few of the trout in Miller Creek, the Williamson or upper Sycan Rivers had scars, and during extensive snorkeling surveys, only a few trout were actually observed with lampreys attached ( S. Reid USFWS pers. com., 2004). Historical reports from Miller Lake prior to the extirpation of lampreys indicate that tui chubs were the principal prey, and dead tui chubs were often reported ( Cochrun 1951a, b, Gerlach 1958, Kan 1975, Kan and Bond 1981). Some cannibalism on other lampreys, as well as scavenging of dead fish carcasses, was also observed ( Kan and Bond 1981). Specific mortality of adult trout was not reported, although large trout were noted to have collections of scars and some mortality of fingerlings was observed. Recent observations of occasional fingerling trout mortality and much more frequent lethal predation on speckled dace (< 10 cm TL) in the Sycan River and Jack Creek, as well as the observation of apparently healthy adult trout with healed wounds, suggests that lethal predation on trout is generally limited to fingerlings ( Markle pers. com. 2004, Reid pers. com. 2004, Smith pers. com. 2004). It is not believed that predation on Miller Lake lamprey by piscivorous adult trout has been a threat to the sustainability of lamprey populations. These populations have co- evolved with native trout and appear to be productive enough to withstand some level of predation. The Jack Creek population is an exception. Jack Creek is believed to only support populations of Miller Lake lamprey and speckled dace. Since this lamprey population evolved absent predation from trout, there is a concern that an introduction of piscivorous adult trout could upset the ecological balance in Jack Creek and present a threat to both the lamprey and dace populations. For this reason, stocking of hatchery fish is prohibited by rule in Jack Creek or other streams containing Miller Lake lamprey. Miller Lake Fisheries - Miller Lake currently supports a recreational trout fishery of entirely introduced species. Miller Lake's one notable native species, the Miller Lake Lamprey, was thought extinct when the Oregon Department of Fish and Wildlife Commission approved the current Klamath Basin Fish Management Plan ( ODFW 1997). Today, Miller Lake provides a popular " catchable" and fingerling rainbow trout program, a trophy brown trout fishery, and an under- utilized kokanee population of small- sized individuals ( Smith pers. com. 2004). Due to the role of Miller Lake as a recreational fishery and concerns over the potential impact of lampreys on introduced trout populations in the lake, the history and status of Miller Lake fisheries are summarized below by species. Rainbow trout fingerlings ( 2- 4 inches) were planted in Miller Lake until 1948, when stocking was discontinued due to poor returns. At that time, the poor rainbow fishery was believed to have been due to lamprey predation and competition with resident tui chubs ( Cochrun 1950, Public Review Draft 4- 27- 05 1951a). However, based on the reported poor performance of stocked fingerling rainbows post-treatment ( see below), without either lampreys or tui chubs, it appears that local habitat conditions, and not trophic competition with tui chub or parasitism by lamprey, were driving the poor rainbow population dynamics. Recent observations by ODFW biologists have indicated that while the rainbow trout in Miller Lake are surviving, growing and being harvested by anglers, survival and growth have been, at best, marginal ( Smith pers. com. 2004). Trapnet samples in Miller Lake have been very inefficient at capturing older age class rainbow trout so the average size of sampled trout is not representative of the fish that are available for angler harvest. While trapnet sets typically made in the fall are not particularly good indicators of the rainbow population in Miller Lake, Trapnet sampling of rainbow trout documented an average length of approximately 8 inches in 1988 and approximately 4 inches in 1997. The release of catchable- sized rainbow trout into Miller Lake was initiated in 2001 to supplement the ongoing fingerling stocking program. Brown trout were first introduced into Miller Lake in 1981 and have been stocked annually since. Although small numbers may have been present prior to treatment. Survival and growth of brown trout has been excellent ( Smith pers. com. 2004). Brown trout averaged approximately 17 inches in length in 1998 and approximately 16 inches in 2001. Larger fish captured in trap net sets exceed 10 pounds. Miller Lake was identified by sport- fishing author Denny Rickards as one of the top ten brown trout producing lakes in the western United States. Lampreys themselves, as well as their impaired prey, might in turn serve as additional prey for the large, highly piscivorous brown trout. Stocks of kokanee were introduced to Miller Lake from several states between 1964 and 1971 ( all post- treatment). Kokanee have been very successful reproducing and stocking has not been necessary since 1971. The average size of maturing adults have remained relatively small. Miller Lake is an oligotrophic lake with very low productivity ( Johnson et al. 1985). The length of maturing female kokanee ranged between 7.5- 10 inches between 1965 tol972, and the average size of kokanee females in 2001 was approximately 8 inches. Based on the relatively small length of maturing kokanee females, it appears that environmental conditions or interspecific competition with other trout are driving the kokanee population dynamics. Brook trout were stocked in Miller Lake from the 1930' s until 1948. Brook trout were present in Miller Creek and apparently survived in tributaries during the 1958 treatment, since seven brook trout ( 6- 14 in) were gill- netted from the lake in 1964, prior to introduction of 85,000 kokanee and 150,000 rainbow fingerlings. No brook trout are currently stocked into the lake or tributaries of the lake. A healthy self- sustaining population of brook trout is currently present in Miller Creek, below the lamprey barrier, where they have apparently coexisted with lampreys since both recovered from the 1958 treatment. Tui chubs were present in Miller Lake prior to the 1958 treatment. It is not known whether tui chub were a native or introduced population. However, based on the elevation and atypical tui chub habitat in the lake, it is believed to have been an un- authorized introduction, most probably as a baitfish. Trophic competition between tui chub and rainbow trout has been consistently demonstrated in several Oregon lakes, including Diamond Lake in Douglas County. Tui chub or " roach" problems in Miller Lake were identified by Ken Cochrun ( Fisheries Agent, Oregon State Public Review Draft 4- 27- 05 game Comm.) in his 1950 and 1951 annual reports ( Cochrun 1950, 1951a). However, Mr. Cochrun felt that the " large population" of tui chub would be relatively easy to control compared to the lamprey and hence the need for the radical chemical treatment with toxaphene, which would eliminate both species, rather than rotenone, which would have limited effect on the lamprey ammocoetes in the substrate. In the 1950' s, as is still the case, considerable amount of time was expended by fishery districts controlling tui chub (" roach"), as noted in Mr. Cochrun's annual reports. Tui chubs were never restocked after the treatment and are no longer present in the Miller Lake drainage. One of the goals of this conservation plan for the Miller Lake Lamprey is to re- establish a lamprey population in Miller Lake itself. Historical reports from Miller Lake prior to the extirpation of lampreys nowhere mention specific mortality of adult trout, even when lamprey were abundant, although large trout were noted to have collections of scars ( see above - Lamprey/ Trout Interaction). Based on historical accounts and recent observations from the Upper Sycan drainages, mortality when observed has been on small fish (< 10cm TL). Observations from Miller Lake in the past and recent observations of trophy redband trout fisheries in Upper Klamath Lake indicate that little to no effect is experienced by the fish based on the occurrence of healed lamprey scars. Self- sustaining populations of brown and brook trout ( unstocked) currently coexist with lampreys in Miller Creek below the lamprey barrier. Were lamprey to become reestablished in Miller Lake, they would probably feed primarily on juvenile kokanee, which are abundant in the lake. Although lamprey predation on adult trout may result in some stress and condition loss, the principal effect on adult kokanee and trout fisheries in Miller Lake is likely to be aesthetic, with small round wounds (< l/ 2 in), or scars, on the side of fish. Future Recreational Fish Management The recreational trout and kokanee salmon fisheries in Miller Lake are an extremely valuable fish resource to local community and anglers. All efforts will be made by the Oregon Department of Fish and Wildlife to continue to offer angling recreation at current harvestable levels. In the unlikely event that the re- establishment of the Miller Lake lamprey adversely impacts the trout and kokanee population abundance, then additional fish stocking or other compatible management actions will be initiated as necessary to meet recreational fishery management objectives. Conservation Plan Note: Underlined, bold text in italics represents those portions of the conservation plan that are proposed to be adopted into Oregon Administrative Rule by the Oregon Fish and Wildlife Commission. Purpose This conservation plan is intended to provide guidance for management actions and conservation of the Miller Lake lamprey, Lampetra ( Entosphenus) minima. This is the first step in securing populations that currently exist in the Klamath Basin and in Public Review Draft 4- 27- 05 determining their status, abundance, distribution, and life history needs. As new information on the lamprey becomes available it is expected that this document will be modified and updated to reflect the current state of our knowledge. Species Management Unit and Population Description The Miller Lake Lamprey species management unit is comprised of six documented populations and one uncertain population. They are: • Mainstem Upper Williamson River above Klamath Marsh • Miller Creek • Jack Creek • Sycan River above Sycan Marsh • Long Creek • Coyote Creek • Shake Creek ( lamprey present have not been identified to species) Desired Status The desired status of the Miller Lake lamprey is for the species to be distributed widely throughout its historic range, with populations robust enough to withstand stochastic environmental events, and with both the populations and their habitat secure from anthropogenic threats. Current Status The Miller Lake Lamprey is endemic to the Klamath Basin and was recently re- described ( Lorion et al 2000). It is currently known from two sub- drainages. The Williamson River sub- drainage includes populations in Miller Creek, Jack Creek, Klamath Marsh and the mainstem upper Williamson River. In the Sycan sub- drainage the lamprey exists in Long Creek and in the upper Sycan River above the Sycan Marsh. Information regarding the abundance and population structure of Miller Lake lamprey in these systems is not available, and only anecdotal information is available for the life history or habitat requirements of the species. For detailed information on the current information available for the species see Life History section. No immediate threats to the Miller Lake Lamprey are known to currently exist, except for the barrier to connectivity between Miller Creek and Miller Lake. Public Review Draft 4- 27- 05 Management Strategies The short- and long- term management strategies for the Miller Lake Lamprey species management unit are: Short- term Strategy a) Re- establish connectivity to Miller Lake. Long- term Strategies b) Ensure appropriate habitat conditions and availability within the natural range of Miller Lake lamprey. c) Reduce entrainment or the potential for entrainment of adult and larval lampreys into water diversions. d) Reduce stranding or the potential for stranding of larval lampreys in dewatered segments of streams below water diversions. e) Maintain unobstructed opportunities, within and among populations for genetic exchange, natural dispersal or migration activities, and re- colonization of unoccupied portions of historical habitat. f) No hatchery fish shall be stocked in streams that support Miller Lake lamprey. Management strategies are those general conditions relevant to the conservation of the species that are considered essential to ensure its long- term survival within its natural range. Although there are many aspects of a species life- history and management that may play a role in the species' biology, the management strategies include those aspects that are currently considered to be both essential for its long- term survival and that are potentially at risk. Conservation Actions Conservation actions are those specific activities or projects that have been identified as appropriate for the realization of the above conservation goals. General - Due to the general lack of information about the life- history, habitat requirements, and distribution of the Miller Lake Lamprey, any studies which increase our understanding of the species will contribute to future conservation planning and should be supported. Habitat - At this time, the general habitat requirements of the Miller Lake Lamprey populations in the upper Williamson and upper Sycan drainages appear to be similar to those of the native trout populations, and habitat restoration or enhancement projects that benefit the trout populations should be beneficial to the lamprey as well. However, there may be specific differences between these species that should be considered in future projects as our understanding of the lamprey's life- history increases. Public Review Draft 4- 27- 05 Entrainment - At this time there has been no evaluation of potential entrainment risks to the Miller Lake Lamprey. Unscreened or improperly screened irrigation diversions currently exist on the upper Sycan and upper Williamson River systems. Private irrigator participation into the screening program should continue to be encouraged and supported. Stranding - At this time there has been no evaluation of potential stranding risks to the Miller Lake Lamprey. Current water diversions reduce the stream flow in segments of the streams directly below the diversion point. Minimum stream flows or gradual ramping strategies should be encouraged where practicable. Connectivity - The Miller Lake Lamprey is not known to carry out extensive spawning migrations. However, due the tendency for ammocoetes to drift downstream during the multi- year larval stage, it is essential that local populations have free upstream passage opportunities during the period when adults are residing in the stream. The swimming characteristics and passage capabilities of trout ( for whom many fish ladders are designed) and lamprey are very different. Lamprey- friendly ladders or passage corridors should be encouraged in the design phase of new projects, and occupied lamprey streams should be evaluated for the presence of older fish ladders, as well as other artificial barriers. Re- establishment of the Miller Lake population - Miller Lake itself, the type locality for the species, remains the only known historical habitat from which the Miller Lake Lamprey is known to have been extirpated. It also represents both an ecologically unique habitat and a crucial component in the evolutionary legacy of the species. Following the extirpation of lampreys from Miller Lake in 1958, a lamprey barrier was constructed in Miller Creek to prevent recolonization of the lake from Miller Creek. The barrier remains in place today. Removal of this barrier should have a high priority in order to meet the conservation goals for the Miller Lake Lamprey and is discussed in more detail below. The barrier was constructed by the State of Oregon Game Commission in 1959 at the upstream extent of a short, high- gradient cascade in Miller Creek approximately 54 mile downstream from the outlet of Miller Lake and forest road 9772. It consists of a low stonework dam ( about 2 ft high) constructed of mortared native rocks, with a metal plate and lip bolted on top. The configuration is very effective as a man- made barrier to fish passage. However, the current condition of the concrete and rock structure is substantially deteriorated. A recent examination by ODFW, USFWS and USFS personnel indicates that the structure would be relatively easy to remove using hand tools without adverse instream impacts ( evaluated by R. Smith et al., September 2003). Recent baseline surveys ( August 2004) of lamprey ammocoetes in the Miller drainage indicate that they are apparently limited to less than two miles of low- gradient stream in lower Miller Creek ( Gunckel and Reid 2004). Allowing lampreys to re- establish a population above the cascade in Miller Creek and Miller Lake will aid in creating an additional buffer against stochastic events that could otherwise eradicate this geographically limited population. Additional surveys should be scheduled on a five- 10 Public Review Draft 4- 27- 05 year basis to evaluate status of the population and the success of re- colonization efforts. Removal of the barrier should allow natural expansion of the population and recolonization of the lake from the Miller Creek population, which survived the original extirpation. Information Gaps 1) Life history - very little quantitative information is available on the life history and habitat requirements of either ammocoetes or adults with which to guide management decisions. 2) Distribution - current understanding of distribution is based on surveys in the 1990' s that primarily focused on the Williamson and Sprague River drainages. Other potential areas in the Klamath Basin outside these drainages have not been properly surveyed. 3) No specific population or fine- scale distributional surveys have been undertaken for any populations outside of the Miller Lake drainage. 4) Preliminary morphological and genetic information suggests that there are regional differences between the various populations of Miller Lake Lamprey in the Klamath Basin. However, the available information is not yet sufficient for making management decisions relative to population independence or uniqueness. Strategies to Address Gaps 1) A Miller Lake Lamprey Technical Management Team has been formed to promote investigation, management and conservation of the Miller Lake Lamprey. This team currently consists of biologists from ODFW ( Roger Smith and Stephanie Gunckel), Oregon State University ( Douglas Markle), the Western Lamprey Project ( Stewart Reid), and the Great Lakes Inst. Environmental Research ( Margaret Docker - lamprey genetics). 2) ODFW will, where appropriate, incorporate lampreys into their fish survey protocols in the Klamath Basin and will seek to collaborate with other researchers carrying out lamprey surveys in the Basin. 3) ODFW and the Miller Lake Lamprey Technical Management Team will promote the investigation of morphological and genetic information informative to resolving regional differences between the various populations of Miller Lake Lamprey. 11 Public Review Draft 4- 27- 05 Research, Monitoring and Evaluation Research Promote scientific studies of the Miller Lake Lamprey to aid in the conservation of the Monitoring Where appropriate, incorporate lampreys into fish survey protocols in the Klamath Basin and seek to collaborate with other researchers carrying out lamprey surveys in the Basin. Evaluation Periodically evaluate the status of Miller Lake lamprey and the success of the conservation plan management strategies. Research - Due to the paucity of available quantitative information on the distribution, life history, habitat requirements of either ammocoetes or adults, ODFW will promote scientific studies of the Miller Lake Lamprey to aid in the conservation of the species. Monitoring - ODFW, in collaboration with USFWS, has documented baseline distribution of the fish in Miller Creek with the lamprey barrier in place ( Gunckel and Reid 2004). Monitoring of the population will continue to evaluate upstream movement, distribution, abundance, and re- colonization of the lake through the cooperative effort of ODFW and the Miller Lake Lamprey Technical Management Team. The ODFW and the Technical Management Team, will meet and discuss progress after the barrier has been removed, and the lampreys have had unobstructed passage to Miller Lake for five years. Adaptive Management a) A Miller Lake Lamprey Technical Management Team shall be formed. b) The Miller Lake Lamprey Technical Management Team shall meet periodically to review the success of the management actions identified in the Miller Lake Lamprey Conservation Plan and identify modifications to management actions that are needed to achieve the desired status for Miller Lake lamprey. No immediate threats to the Miller Lake Lamprey are known to currently exist, except for the barrier in Miller Creek. The Miller Lake Lamprey Technical Management Team ( see under Strategies to Address Gaps) has been formed to promote investigation, management and conservation of the Miller Lake Lamprey. The team will meet periodically to evaluate current status and management strategies in light of new information. 12 Public Review Draft 4- 27- 05 Current management action is proposed for removal of the Miller Creek Barrier. The lamprey population in Miller Creek will continue to be monitored by ODFW following the 2004 baseline surveys. After five years the Miller Lake Lamprey Technical Management Team will evaluate the status of the Miller Creek population and the success of natural re- colonization of Miller Lake. If sufficient progress has not been made, then discussions regarding active re- introduction of lampreys to the lake will be initiated. Trigger for Plan Modification Substantial negative changes in the distribution or abundance of the Miller Lake lamprey, or the recognition of new threats to the species, shall prompt a review of the species management unit's status and all Miller Lake Lamprey Conservation Plan management strategies by the Miller Lake Lamprey Technical Management Team. Appropriate modifications to the Miller Lake Lamprey Conservation Plan intended to better achieve the desired status identified in the Plan shall be proposed by the Miller Lake Lamprey Technical Management Team. Reporting a) The Miller Lake Lamprey Technical Management Team shall periodically report on the status of Miller Lake lamprey and the effectiveness of the management strategies identified in the Miller lake Lamprey Conservation Plan. b) Annual Miller Lake Lamprey data collected and any reports on the status of Miller Lake Lamprey or evaluations of the Miller Lake Lamprey Conservation Plan shall be made available to the public. The staff of the ODFW's Klamath Watershed District and Native Fish Research Project will periodically report monitoring and research results through native fish conservation strategy stock status reviews. 13 Public Review Draft 4- 27- 05 Citations Bond, C. E. and T. T. Kan. 1973. Lampetra ( Entosphenus) minima n. sp., a dwarfed parasitic lamprey from Oregon. Copeia 1973: 568- 574. Cochran, P. A. and R. E. Jenkins. 1994. Small fishes as hosts for parasitic lampreys. Copeia 1994: 499- 504. Cochrun, K. 1950. Annual Report - Fishery Division, Central Region, Klamath District: Miller Lake. Oregon State Game Commision. Cochrun, K. 1951a. Annual Report - Fishery Division, Central Region, Klamath District: Miller Lake. Oregon State Game Commision. Cochrun, K. 1951b. Letter to Dr. HJ. Rayner, Chief of Fisheries Operations, Oregon State Game Commission. 4 November 1951. Gerlach, A. 1958. Rehabilitation of Miller Lake, 1958. Report to files - Fishery Division, Central Region, Klamath District. Oregon State Game Commision. Gerlach, A. 1959. Annual Report - Fishery Division, Central Region, Klamath District: Miller Lake. Oregon State Game Commision. Gerlach, A. and R. Borovicka. 1964. State- wide fishery rehabilitation: Miller Lake and tributaries segment ( Completion Report F- 20- D- 11). Oregon State Game Commission. Gill, H. S., C. B. Renaud, F. Chapleau, R. L. Mayden and I. C. Potter. 2003. Phylogeny of living parasitic lampreys ( Petromyzontiformes) based on morphological data. Copeia 2003: 687- 703. Gunckel S. and S. Reid. 2004. Baseline survey of Miller Lake Lamprey ( Entosphenus minimus) ammocoete distribution in the Miller Lake subdrainage. Oregon Dept. Fish and Wildlife. Hubbs, C. L. 1971. Lampetra ( Entosphenus) lethophaga, new species, the nonparasitic derivative of the Pacific lamprey. Trans. San Diego Soc. Nat. Hist. 16: 125- 164. Johnson, D. M., R. R. Peterson, D. R. Lycan, J. W. Sweet, M. E. Neuhaus and A. L. Schaedel. 1985. Miller Lake In Atlas of Oregon Lakes. Oregon State Univ. Press. Corvallis, Oregon. Kan, T. T. 1975. Systematics, variation, distribution, and biology of lampreys of the genus Lampetra in Oregon. Doctoral Dissertation, Oregon State Univ., Corvallis, Oregon. Kan, T. T. and C. E. Bond. 1981. Notes on the biology of the Miller Lake lamprey Lampetra { Entosphenus) minima. Northwest Sci. 55: 70- 74. 14 Public Review Draft 4- 27- 05 Kostow, K. 2002. Oregon lampreys: natural history, status and analysis of management issues. Info. Rept. 2002- 01, Fish Division, Oregon Dept. Fish and Wildlife. Lorion, CM., D. F. Markle, S. B. Reid and M. F. Docker. 2000. Redescription of the presumed-extinct Miller Lake Lamprey, Lampetra minima. Copeia 2000: 1019- 1028. Oregon Dept. Fish and Wildlife. 1997. Klamath River Basin, Oregon - Fish Management Plan, August 22, 1997. Personal Communications Docker, Margaret F. - Great Lakes Inst. Environmental Research, Univ. Windsor; 401 Sunset Ave, Windsor, ON N9B 3P4 Goodman, Damon - Fisheries Biology, Humboldt State Univ.; 1 Harpst Street, Arcata, CA 95521- 8299 Markle, Doug F. - Dept. Fisheries and Wildlife, Oregon State Univ.; 104 Nash Hall, Oregon State Univ., Corvallis, OR 97331- 3803 Reid, Stewart B. - U. S. Fish and Wildlife Service, Endangered Species Division; 6610 Washburn Way, Klamath Falls, OR 97603; Current address - Western Fishes, 2045 East Main, Ashland OR 97520 Smith, Roger C. - District Fish Biologist, Oregon Dept. Fish and Wildlife; 1850 Miller Island Road West, Klamath Falls, OR 97603 15
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Klamath River Fish Die-off, September 2002, Mortality Report, FWS, Arcata, CA Summary of Findings This report provides an estimate of the fish mortality that occurred during the September 2002 Klamath ...
Citation Citation
- Title:
- Klamath River fish die-off, September 2002 : report on estimate of mortality
- Author:
- Guillen, George.
- Year:
- 2003, 2005, 2004
Klamath River Fish Die-off, September 2002, Mortality Report, FWS, Arcata, CA Summary of Findings This report provides an estimate of the fish mortality that occurred during the September 2002 Klamath River die-off. The intent of this report is to provide natural resource agencies and trustees with information describing the magnitude of this event for their consideration in near-term decisions regarding the affected fisheries resources and related assets under their authority. The Fish and Wildlife Service (Service), in cooperation with other federal and state agencies and Tribes, will continue to collaborate and evaluate information collected during the die-off. This report describes a conservative assessment, which probably underestimates the total number of fish that died during this event. Findings described in this report include the following: 22 The most accurate estimate of the total number of observable fish that died during the incident is 34,056. 22 Approximately 98.4 percent of the dead fish observed were adult anadromous salmonids 22 Out of 33,527 anadromous salmonids estimated to have succumbed during this event, 97.1 percent (32,533) were fall-run Chinook salmon, Oncorhynchus tshawytscha, 1.8 percent (629) were steelhead, O. mykiss, and 1.0 percent (344) were coho salmon, O. kisutch. Only one coastal cutthroat, O. clarki clarki was found dead during the investigation. 22 Approximately 91.5 percent of the coho salmon, and 38.7 percent of the steelhead observed had marks indicating that they were of hatchery origin. All hatchery coho originated from the Trinity River Hatchery. After accounting for variable tagging and shed rates, the Klamath River Technical Advisory Team (KRTAT) estimated that 7,060 (21.7 percent) Chinook were of hatchery origin. A total of 2,921 (9 percent) Chinook were of Iron Gate (Klamath River) Hatchery origin. A total of 4,139 (12.7 percent) Chinook were of Trinity River Hatchery origin. 22 The KRTAT also estimated that dead Chinook salmon represented 19.2 percent of the total (169,,297) in-river Klamath-Trinity River run. 22 Other dead fish observed during the investigation included sculpins, Cottus spp. (87 fish), speckled dace, Rhinichthys osculus (9 fish), Klamath smallscale sucker, Catostomus rimiculus (311 fish), one American shad, Alosa sapidissima, and one green sturgeon, Acipencer medirostris. ii Klamath River Fish Die-off, September 2002, Mortality Report, FWS, Arcata, CA 22 Throughout the investigation, live adult and juvenile fish of affected and unaffected species were observed in the river. In addition, some species (e.g. American shad, speckled dace, and green sturgeon) did not appear to experience extensive mortality. Almost all (greater than 99 percent) of the dead fish observed were adults or larger species offish. 22 The majority of the recently dead fish examined exhibited one or more outward gross signs of disease including gill necrosis, bacterial growth, sores, bloody vents, and ulcerations. Pathological examinations confirmed that white spot disease and columnaris were the principle immediate causes of death. Additional information collected by the Service and cooperating agencies included a suite of water quality parameters collected during the summer and fall of 2001 and 2002, fish pathology analyses, and related hydrologic information. The Service will provide reports on this additional information after it has received quality assurance review. A more comprehensive report addressing contributing factors associated with causes of the fish die-off will follow. in