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1201. [Article] Hult Reservoir (Siuslaw Basin) Fish Species Composition Size and Relative Abundance_Final2018
Abstract -- Seven species of fish were encountered in Hult Reservoir in 2017: largemouth bass (Micropterus salmoides), cutthroat trout (Oncorhynchus clarkii), tainbow trout/winter steelhead (Oncorhynchus ...Citation Citation
- Title:
- Hult Reservoir (Siuslaw Basin) Fish Species Composition Size and Relative Abundance_Final2018
Abstract -- Seven species of fish were encountered in Hult Reservoir in 2017: largemouth bass (Micropterus salmoides), cutthroat trout (Oncorhynchus clarkii), tainbow trout/winter steelhead (Oncorhynchus mykiss), bluegill (Lepomis macrochirus), reticulate sculpin (Cottus perplexus), brown bullhead (Ameiurus nebulosus) and western brook lamprey (Lampetra richardsoni). The most abundant fish observed were largemouth bass and bluegill in the summer and fall, and cutthroat in the winter. Cutthroat trout were much more prevalent in the fall and winter sampling than in the summer. Presumably, most cutthroat trout moved up into the tributaries to seek thermal refuge during the summer months and returned to the reservoir once the temperatures were more conducive to growth and survival. However, some of them likely moved downstream, were preyed upon, or perished from the high summer temperatures and low dissolved oxygen conditions in the reservoir in summer. Under current conditions, high surface temperature (>20?), bass predation, and hypoxic dissolved oxygen levels below four meters of depth show that reservoir conditions are inhospitable for juvenile salmonids in the summer. Currently there are well established fisheries for both cutthroat trout (spring, fall, winter) and largemouth bass (summer) in the reservoir, and we talked to several anglers who target each of these species. Habitat segregation in the summer between the salmonids who move out of the reservoir and the warm-water fish that remain and spawn in the reservoir results in a diversified year-round angling opportunity. There were no coho salmon (juvenile or adult) observed in Hult Reservoir in 2017, but adult coho salmon were observed spawning just downstream of the dam. This observation verifies that a proportion of the adult coho attempting to ascend the ladder at Lake Creek Falls are successful and continue migration upstream to the vicinity of Hult Reservoir. It may be possible to keep the current fishery in Hult Reservoir as it stands and still increase coho production in the system by improving adult passage at Lake Creek Falls, and possibly at Hult Dam.
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Abstract -- The Oregon Department of Fish and Wildlife (ODFW) has conducted a three year study designed to develop methods that provide reliable estimates of fall chinook salmon (Oncorhynchus tshawytscha) ...
Citation Citation
- Title:
- Fall Chinook Salmon in the South Fork Coos River: Spawner Escapement, Run Reconstruction and Survey Calibration, 1998 - 2000, Information Reports 2003-02
Abstract -- The Oregon Department of Fish and Wildlife (ODFW) has conducted a three year study designed to develop methods that provide reliable estimates of fall chinook salmon (Oncorhynchus tshawytscha) spawner escapements for the South Fork Coos River. This study is part of a larger effort to develop similar high-quality escapement estimates for fall chinook in Oregon coastal basins in order to meet Oregon’s Pacific Salmon Treaty monitoring responsibilities. Funding for this study was provided by the U.S. Section of the Chinook Technical Committee (CTC) of the Pacific Salmon Commission (PSC) pursuant to the 1999 Letter of Agreement (LOA). Three stock aggregates have been identified that originate from Oregon coastal basins. These aggregates are thought to represent distinct genetic and behavioral characteristics and are managed separately. The North Oregon Coast (NOC) and Mid Oregon Coast (MOC) are the two stock aggregates that are north migrating, and are subjected to the PSC’s abundance-based management program (USCTC 1997). The South Fork Coos River is one component of the MOC aggregate. Current monitoring programs for Oregon coastal fall chinook do not supply the CTC with adequate information that is required for the management and rebuilding of Oregon’s coastal chinook stocks. ODFW has conducted standard surveys for more than 50 years to monitor the status of chinook stocks along coastal Oregon (Jacobs et al. 2000). A total of 56 standard index spawner surveys (45.8 miles) are monitored throughout 1,500 stream miles on an annual basis to estimate peak escapement levels and track trends of northmigrating stocks. Although counts in these standard surveys may be sufficient to index long-term trends of spawner abundance, they are considered inadequate for deriving reliable annual estimates of spawner escapement for several reasons. These surveys were not selected randomly and cannot be considered representative of coast-wide spawning habitat. Also, fall chinook are known to spawn extensively in mainstem reaches and large tributaries, which are not conducive to the foot surveys. To provide estimates of escapements, index counts must be calibrated to known population levels. Obtaining accurate estimates of fall chinook spawner density in mainstem reaches is extremely difficult. Typically, these areas exhibit wide variations in stream flow and turbidity that create difficult and sometimes dangerous survey conditions resulting in unreliable visual counts. The goal of this project is to develop precise estimates of adult spawner escapement in the South Fork Coos River and to identify survey methods that can be used to reliably index spawner abundance for the South Fork Coos River and MOC stock aggregate. ODFW conducted mark-recapture experiments to estimate fall chinook spawning escapement in the South Fork Coos River from 1998 through 2000. We conducted foot and float surveys to obtain counts of live fish, carcasses, and redds. These indices are assessed against the mark-recapture estimates to determine whether any of them track fall chinook spawner abundance with sufficient precision to form the basis for long-term monitoring and the incorporation of resulting escapement estimates into PSC harvest modeling efforts. We used radio-telemetry as an independent method to estimate the distribution of fall chinook spawners between mainstem and tributary strata.
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Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. Historically, this species ...
Citation Citation
- Title:
- 2011 Warner Sucker Investigations (Honey Creek) Progress Reports 2011
Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. Historically, this species was abundant and its range included three permanent lakes (Hart, Crump, and Pelican), several ephemeral lakes, a network of sloughs and diversion canals, and three major tributary drainages (Honey, Deep, and Twentymile Creeks) (U.S. Fish and Wildlife Service 1985). Warner sucker abundance and distribution has declined over the past century and it was federally listed as threatened in 1985 due to habitat fragmentation and threats posed by the proliferation of piscivorous non-native game fishes (U.S. Fish and Wildlife Service 1985). The Warner sucker inhabits the lakes and low gradient stream reaches of the Warner Valley. The Warner sucker metapopulation is comprised of both lake and stream life history morphs. The lake suckers are lacustrine adfluvial or potamodromous fish that normally spawn in the streams. However, upstream migration may be blocked by low stream flows during low water years or by irrigation diversion dams. When this happens, spawning may occur in nearshore areas of the lakes (White et al. 1990). Large lake-dwelling populations of introduced fishes likely reduce recruitment by preying on young suckers (U.S. Fish and Wildlife Service 1998). The stream suckers inhabit and spawn in Honey, Deep, and Twentymile Creeks. The Recovery Plan for the Threatened and Rare Native Fishes of the Warner Basin and Alkali Subbasin (U.S. Fish and Wildlife Service 1998) sets recovery criteria for delisting the species. These criteria require that: 1) a self-sustaining metapopulation is distributed throughout the Twentymile, Honey, and Deep Creek (below the falls) drainages, and in Pelican, Crump, and Hart Lakes, 2) passage is restored within and among the Twentymile, Honey, and Deep Creek (below the falls) drainages so that the individual populations of Warner suckers can function as a metapopulation, and 3) no threats exist that would likely threaten the survival of the species over a significant portion of its range. To inform progress towards the first criteria, our objectives in 2011 were: 1) obtain a population estimate for suckers in the Honey Creek drainage and describe their current distribution and 2) describe the association between the distribution of suckers and habitat variables in Honey Creek. In addition, we obtained a population estimate of suckers at the Summer Lake Wildlife Management Area (WMA), where a self-sustaining population became established after a fish salvage from Hart Lake in 1991 when the lakes desiccated.
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1204. [Article] Warner Sucker Investigations (2009)
Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. Historically, this species ...Citation Citation
- Title:
- Warner Sucker Investigations (2009)
Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. Historically, this species was abundant and its range included three permanent lakes (Hart, Crump, and Pelican), several ephemeral lakes, a network of sloughs and diversion canals, and three major tributary drainages (Honey, Deep, and Twentymile Creeks) (U.S. Fish and Wildlife Service 1985). Warner sucker abundance and distribution has declined over the past century and it was federally listed as threatened in 1985 due to habitat fragmentation and threats posed by the proliferation of piscivorous non-native game fishes (U.S. Fish and Wildlife Service 1985). The Warner sucker inhabits the lakes and low gradient stream reaches of the Warner Valley. The Warner sucker metapopulation is comprised of both lake and stream life history morphs. The lake suckers are lacustrine adfluvial or potamodromous fish that normally spawn in the streams. However, upstream migration may be blocked by low stream flows during low water years or by irrigation diversion dams. When this happens, spawning may occur in nearshore areas of the lakes (White et al. 1990). Large lake-dwelling populations of introduced fishes likely reduce recruitment by preying on young suckers (U.S. Fish and Wildlife Service 1998). The stream suckers inhabit and spawn in Honey, Deep, and Twentymile Creeks. The Recovery Plan for the Threatened and Rare Native Fishes of the Warner Basin and Alkali Subbasin (U.S. Fish and Wildlife Service 1998) sets recovery criteria for delisting the species. These criteria require that: 1) a self-sustaining metapopulation is distributed throughout the Twentymile, Honey, and Deep Creek (below the falls) drainages, and in Pelican, Crump, and Hart Lakes, 2) passage is restored within and among the Twentymile, Honey, and Deep Creek (below the falls) drainages so that the individual populations of Warner suckers can function as a metapopulation, and 3) no threats exist that would likely threaten the survival of the species over a significant portion of its range. Objectives of our 2009 investigations included: 1) obtain a mark-recapture population estimate for suckers in the Twentymile Creek drainage and describe their current distribution, 2) describe associations between the distribution of suckers and habitat variables in Twentymile Creek, 3) evaluate a non-lethal ageing technique, 4) track radiotagged lake suckers (tagged in 2008) in Hart and Crump Lakes to assess spring movement patterns, 5) track spring spawning movements of lake suckers across a PIT-tag antenna installed at the mouth of Honey Creek, 6) test the feasibility of trapping larval suckers near the mouth of Honey Creek using larval drift nets and light traps to describe the relative abundance and timing of larval sucker movements, and 7) obtain a mark-recapture population estimate of suckers at the Summer Lake Wildlife Management Area (WMA), where a self-sustaining population became established after a fish salvage from Hart Lake during the 1991 drought.
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Abstract -- The Willamette and Sandy rivers support intense recreational fisheries for spring Chinook salmon (Oncorhynchus tshawytscha). Fisheries in these basins rely primarily on annual hatchery releases ...
Citation Citation
- Title:
- Spring Chinook in the Willamette and Sandy Basins, Progress Reports 2006-2007
Abstract -- The Willamette and Sandy rivers support intense recreational fisheries for spring Chinook salmon (Oncorhynchus tshawytscha). Fisheries in these basins rely primarily on annual hatchery releases of 5–8 million juveniles. Hatchery programs exist in the McKenzie, Middle Fork Willamette, North and South Santiam, Clackamas, and Sandy rivers mainly as mitigation for dams that blocked natural production areas. Some natural spawning occurs in most of the major basins and a few smaller tributaries upstream of Willamette Falls. The Oregon Fish and Wildlife Commission adopted the Native Fish Conservation Policy (ODFW 2003a) and the Hatchery Management Policy (ODFW 2003b) in part to reduce adverse impacts of hatchery programs on wild native stocks. The Native Fish Conservation Policy recognizes that naturally produced native fish are the foundation for long-term sustainability of native species and hatchery programs, and the fisheries they support. Possible risks of artificial propagation programs have been well documented. Hazards include disease transfer, competition for food and spawning sites, increased predation, increased incidental mortality from harvest, loss of genetic variability, genetic drift, and domestication (Steward and Bjornn 1990; Hard et al. 1992; Cuenco et al. 1993; Busack and Currens 1995; NRC 1996; and Waples 1999). Hatcheries can also play a positive role for wild salmonids by bolstering populations, especially those on the verge of extirpation, by providing a genetic reserve as well as providing opportunities for nutrient enrichment of streams (Steward and Bjornn 1990; Cuenco et al. 1993). In the past, hatchery programs and fish passage issues were the focus of spring Chinook salmon management in the Willamette and Sandy basins. Limited information was collected on the genetic structure among basin populations, on abundance and distribution of natural spawning, on rearing and migrating of juvenile salmon, or on strategies for reducing risks that large hatchery programs pose for wild salmon populations. This study is being implemented to gather this information. A schematic of the study plan is shown in APPENDIX A. We conducted work in the main-stem Willamette River above Willamette Falls, and in the Middle Fork Willamette, McKenzie, North Santiam, South Santiam, Clackamas, and Sandy rivers in 2006 and 2007. Basin descriptions and background information on management and fish runs can be found in subbasin plans developed by the Oregon Department of Fish and Wildlife (ODFW 1988, ODFW 1992a, ODFW 1992b, and ODFW 1996). Task headings below cross reference the study plan outlined in APPENDIX A. This report covers tasks that were worked on in late 2005 through early fall 2007.
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Abstract -- This is the second report in an annual series of four reports prepared by the Salmon Technical Team (STT) of the Pacific Fishery Management Council (Council) to document and help guide salmon ...
Citation Citation
- Title:
- Preseason Report I, Stock Abundance Analysis for 1998, Ocean Salmon Fisheries
Abstract -- This is the second report in an annual series of four reports prepared by the Salmon Technical Team (STT) of the Pacific Fishery Management Council (Council) to document and help guide salmon fishery management off the coasts of Washington, Oregon, and California. This report will be formally reviewed at the Council's March meeting. The third and fourth reports in this series will be developed at the close of the March and April Council meetings, respectively. They will analyze the impacts of the Council's proposed and final ocean salmon fishery management recommendations for 1998. This report provides 1998 salmon stock abundance projections and an analysis of the impacts of 1997 regulations, or regulatory procedures. The report focuses on chinook and coho stocks that have been important in determining Council fisheries in recent years. However, decisions on whether or not to propose Endangered Species Act listings for several chinook stocks ranging from central California to Puget Sound are anticipated in the near future. In the event that the National Marine Fisheries Service proposes new listings, information concerning the status of these stocks may significantly affect Council deliberations on the final salmon fishing seasons. Chapter I provides a summary of the 1998 stock abundance projections. Chapters II and Ill provide detailed stock-by-stock analyses of abundance and a description of prediction methodology and accuracy of past abundance predictions for chinook and coho salmon, respectively. Chapter IV summarizes abundance information for pink salmon. Four appendices provide supplementary information as follows: Appendix A provides a summary of Council stock management goals; Appendix 8 contains pertinent data for Oregon production index (OPI) area coho; Appendix C provides historical salmon catch data for the Cape Flattery and Strait of Juan de Fuca areas; and Appendix D contains the Council's current harvest allocation schedules. Summaries of preseason and postseason abundance estimates are included in: • Table 11-2 for Central Valley Index fall chinqok since 1985; • Table 11-4 for Klamath River fall chinook since 1985; • Table 11-8 for selected Columbia River fall chinook stocks since 1984; • Table 11-9 for Puget Sound summer/fall chinook stocks since 1993; • Table 111-1 for OPI area produced coho stocks since 1992 and • Table 111-3 for selected naturally spawning Puget Sound and Washington coastal coho stocks since 1984. Differences between preseason and postseason estimates are caused by a number of factors, including: (1) inaccuracies in abundance forecasts for these and other stocks which are exploited by mixed stock fisheries, (2) deviations of actual catches and fishery patterns from preseason expectations, (3) anomalies in stock distribution and migration patterns, and (4) for the Puget Sound coho stocks, differences in assessment methodologies (postseason estimates are based on run reconstruction assumptions which differ substantially from those represented in the Fishery Regulatory Assessment Model). The STT has not been able to complete a proper evaluation of abundance estimates which would take all these factors into account.
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1207. [Article] Abundance, Productivity, and Life History of Fifteenmile Creek Steelhead; Annual Report 2016
Abstract -- The Fifteenmile Creek watershed in North Central Oregon hosts a native population of steelhead (Oncorhynchus mykiss) that is without influence of previous hatchery augmentation. The Fifteenmile ...Citation Citation
- Title:
- Abundance, Productivity, and Life History of Fifteenmile Creek Steelhead; Annual Report 2016
Abstract -- The Fifteenmile Creek watershed in North Central Oregon hosts a native population of steelhead (Oncorhynchus mykiss) that is without influence of previous hatchery augmentation. The Fifteenmile Creek steelhead are a subpopulation within the Distinct Population Segment (DPS) of the Middle Columbia River steelhead and was listed as ‘threatened’ by the National Marine Fisheries Service (NMFS) first on March 25, 1999 and relisted as a DPS on January 5, 2006. Subsequently, a conservation and recovery management plan was developed for the Middle Columbia River steelhead DPS within Oregon state borders. The goal of the plan is to recover Middle Columbia River steelhead to a level that would allow the removal of threatened status, in addition to providing a long-term goal to recover the population sufficiently to provide sustainable fisheries and other ecological, cultural, social and economic benefits for future generations. The DPS-level recovery plan sets specific recovery goals for the areas within the DPS, which designates Fifteenmile Creek explicitly. The Fifteenmile Creek steelhead population is considered the most inland winter race of steelhead in the Columbia River Basin, as designated by NOAA fisheries. However review of this designation may be necessary at the next Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) status-review because the run-timing of adult steelhead passing Bonneville Dam has been inconsistent with known winter-run steelhead in the area. The population was identified as “must have viable” status by the Interior Columbia Technical Recovery Team (ICTRT), and reaching viable status is essential for achieving DPS delisting. The ICTRT, Recovery Plan, and the Federal Columbia River Power System (FCRPS-BiOp) have all identified this population as high priority for improving precision and accuracy of abundance, productivity, diversity, and spatial structure information.
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1208. [Article] A Proposal for an Integrated Research Monitoring Program for Oregon Coastal Chinook Populations
Abstract -- Among the many chinook salmon populations contributing to large, mixed stock ocean net, troll, and recreational fisheries managed by the Pacific Salmon Commission (PSC) there is a good deal ...Citation Citation
- Title:
- A Proposal for an Integrated Research Monitoring Program for Oregon Coastal Chinook Populations
Abstract -- Among the many chinook salmon populations contributing to large, mixed stock ocean net, troll, and recreational fisheries managed by the Pacific Salmon Commission (PSC) there is a good deal of diversity with respect to productivity, life history characteristics, and ocean distribution. During the years immediately following the adoption of the original 1985 Pacific Salmon Treaty (PST), lack of adequate data prevented the PSC from managing effectively for these differences. Instead, chinook management outlined in Annex IV of the original treaty was based upon long term population trends for very large aggregates of stocks. Although harvest ceilings were established as part of a PST recovery plan for over-exploited stocks, they were based on average coast-wide production trends and resulted in over harvest of weak stocks in some years and failure to take advantage of large returns in other years. By the mid-l 990's, data relative to the distribution and abundance of many salmon stocks contributing to PST fisheries was improving. At the same time, there was increasing dissatisfaction with quota-based management and strong interest in instituting annual abundance-based management for stock aggregates that share geographic proximity of spawning areas, similar life history and genetic characteristics, and similar distributions in the ocean. Abundance-based management for aggregated stocks would establish and implement annual fishery exploitation rates in fisheries that insure long-term sustainability for all aggregates and related individual stocks. In the absence of bilateral agreement between the U.S. and Canada regarding implementation of abundance-based management, the three voting U.S. PSC Commissioners signed the 1996 Letter of Agreement (LOA) that defined elements of an abundance-based management approach for chinook salmon fisheries in southeast Alaska. The LOA was designed to: 1) set the stage for future bilateral negotiations regarding abundance based management; 2) clarify the role of PST fisheries in rebuilding depressed natural stocks; and 3) provide a means for sharing conservation responsibility of far-north migrating stocks originating from watersheds in Oregon and Washington. The foundation for abundance-based management set forth in the LOA was subsequently expanded upon and incorporated as Aggregate Abundance-Based Management (AABM) in Annex IV, Chapter 3 of the 1999 PST. Application of the abundance-based management outlined in the 1996 LOA and the subsequent 1999 amendments to the PST requires knowledge of the stock recruitment relationships, biological spawning escapement goals, and annual forecasts of ocean abundance and distribution for stocks in each aggregate to regulate fishery harvest. Managers must also have annual post-season estimates of aggregate specific exploitation rates and in-river escapements to assess the effectiveness of regulatory measures. The base-monitoring program for Oregon's coastal chinook under the 1985 PSC met only a few of these data requirements. In recognition of requirements for new and more precise data, the signatories of the original LOA sought out additional federal funds for new and expanded monitoring programs. Since 1997 Congress has annually approved approximately $1.8 million for additional research and monitoring needed to implement terms of the LOA. The PSC delegated discretionary authority for the use of those funds to the U.S. Section's Chinook Technical Committee (CTC).
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This fifth annual Cooperative Pole Research Program report outlines our progress in the six project objectives. Improved Fumigants Sampling of previously established field tests revealed that Vorlex and ...
Citation Citation
- Title:
- Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1985
- Author:
- Oregon State University, Oregon State University. Dept. of Forest Products
This fifth annual Cooperative Pole Research Program report outlines our progress in the six project objectives. Improved Fumigants Sampling of previously established field tests revealed that Vorlex and Chloropicrin continued to perform well after 15 years, while Vapam was slightly less effective. Solid methylisothiocyanate (MIT) also performed well in the field after 7 years. In additional tests, gelatin encapsulated MIT migrated through Douglas-fir heartwood with addition of moderate quantities of water to degrade the gelatin. However, in the presence of higher quantities of water or no additional water, MIT migration into the wood was slowed. In a previously established test, gelatin encapsulated MIT continues to inhibit reinfestation of poles 3 years after treatment. Pelletized MIT is a new formulation (65% active ingredient) that appears to have some promise. Preliminary tests indicate that up to 95% of the MIT is release in 24 hours, but a small quantity of MIT remains in the pellets after 63 days aeration and may pose a disposal hazard. The solid MIT formulations will permit aboveground applications, increasing the risk that MIT will come in contact with pole hardware. Preliminary tests indicate that MIT had little effect on corrosion of hot dipped, galvanized bolts attached to wood. This suggests that treatment in the crossarm zone with MIT or fumigants that produce MIT should not affect the integrity of attached hardware. i-i In addition to fumigant evaluations, we recently examined an earlier test of groundline treatments with Osmoplastic® and Hollowheart®. After 10 years, these treatments are performing reasonably well, with only a slight rise in the incidence of decay fungi in the past 4 years. We also reevaluated the effectiveness of kerfing for preventing decay and found that this process reduced the depth and width of checks, resulting in a decreased incidence of decay fungi. Kerfing appears to be a valuable method for preventing internal decay at the groundline. Cedar Sapwood Decay Control This past year, the second set of five chemicals applied to control sapwood decay were evaluated after 2 years of exposure. As in earlier evaluations using the Aspergillus bioassay, none of the chemicals approach pentachlorophenol in oil for ability to inhibit sporulation of Aspergillus niger; however, several samples from zones deep in the wood produced a slight zone of effect. This may indicate the presence of a reservoir for long-term protection against decay. Several of the chemicals including Fluor Chrome Arsenic Phenol and Ammoniacal Copper Arsenate (ACA) appear to bind to the wood and may be difficult to detect by the bioassay method. We expect to assess the effectiveness of these treatments using a soil block test. Investigations of the reliability of the Aspergillus bioassay under a variety of conditions indicated that quantity of spores, use of glass or plastic petri dishes, long-term cold storage, and the use of spray inoculum instead of flooding spores had little influence on the bioassay results with pentachiorophenol, Tributyl-tinoxide, or 3 iodo propynyl butylcarbamate; however, incubation temperature did influence assay results. The Aspergillus bioassay is a simple, effective means for estimating residual preservative levels. Bolt Holes Again this year, wood around the unprotected, control bolt holes in pole sections contained such low levels of decay fungi that evaluation of the treated poles will be delayed another year. In addition to the initial bolt hole treatments, we have begun a test to determine if gelatin encapsulated or pelletized MIT can prevent decay development in field-drilled bolt holes. The pole sections used in these tests had already begun to develop decay prior to treatment and will provide an ideal test material. Detecting Decay and Estimatin& Residual Strength of Poles Fluorescent labeled lectins used in our earlier studies detected decay fungi at low weight losses under laboratory conditions. We are currently evaluating this method for detecting fungi in increment cores removed from poles to reduce the need for culturing. Last year we identified a peak that was unique to infrared (IR) spectra of warm water extracts from decayed wood. This past year we attempted to identify the chemical responsible for this peak and found that carbonyl compounds, probably from oxidative lignin degradation, were responsible for the peak. Since brown rot fungi apparently do iv not completely metabolize lignin breakdown products, they accumulate in the decaying wood and can be readily detected by their IR spectra. Strength properties of beams cut front Douglas-fir pole sections, air-seasoned for 3 years significantly decreased although decay fungi could not be uniformly isolated from the beams. In addition, there were gradual declines in work to maximum load and modulus of elasticity, as well as increased Pilodyn pin penetration. These results suggest that some strength losses occurred during air-seasoning; however, the losses were not large and should not endanger pole users. We compared several test methods including the Pilodyn, radial compression tests, longitudinal compression tests, and the pick test for evaluating residual pole strength of the wood surface of Douglas-fir treated with combinations of funtigants or groundline wraps. The results indicate that only the pick test could accurately detect surface damage and illustrate the difficulty of detecting surface damage. This past year we evaluated several sections cut from ACA treated poles stored for a number of years to determine if they were worth salvaging. Static bending tests of beams cut from the ACA treated zone, the treated/untreated boundary, and the inner heartwood revealed ACA treated sapwood had lower MOR and longitudinal compression strength than the other zones. These results represent only a small sample, but they suggest that some strength loss occurs during ACA V treatments. More importantly, the results suggest that we could have reliably predicted beam MOR by testing small plugs removed from the poles. Small beams cut from decaying, pentachlorophenol treated Douglas-fir poles were acoustically tested for residual wood strength, then evaluated to failure in static bending. The acoustic test consisted of sending a pulsed sonic wave into the wood and recording this wave after it passed through the beam. As it moved, the wave was altered by the presence of any wood defects or decay, and these alterations create a "fingerprint" specific for that defect. Preliminary results indicated that signal analysis was highly 2 2 correlated with work to maximum load (r =.82) and MOR (r .88), suggesting that this approach to decay detection may prove more reliable than measuring of sound velocity. Initiation of Decay in Air-Seasoning Douglas-fir The results of the initial survey to determine the incidence of decay fungi in poles from widely scattered Pacific Northwest seasoning yards indicated that a variety of fungi were colonizing the wood. While most of these fungi do not pose a serious decay problem, two species, Poria carbonica and Poria placenta, became increasingly abundant with length of air-seasoning. These fungi are also the most conunon decayers of Douglas-fir poles in service. As expected, the number of fungi and the wood volume they occupied increased with seasoning time; however, this incidence varied considerably between yards, especially in poles air-seasoned for vi shorter time periods. In addition to the variation between sites, many of the decay fungi colonizing the wood appear to be monokaryons, indicating that spores landing on the wood are initiating the infestation. The distribution of fungi within the poles indicated that several of the more abundant decay fungi were present in the outer sapwood where they would be eliminated by conventional pressure treatment. The remaining fungi were most abundant in the heartwood but were more concentrated near the pole end. This suggests that exposed end grain was more readily invaded than lateral grain exposed in checks. In addition to identifying the fungi colonizing Douglas-fir, we examined the effects these fungi had on wood strength. Toughness tests indicated the presence of wide variation in decay capability of the isolates. Although there was no consistent pattern, most of the isolates did not cause substantial decay and, of those that did, only . carbonica and P. placenta were sufficiently abundant to have a large influence on wood strength. Due to the prevalence of P. carbonica and P. placenta in the inner heartwood, where they might not be eliminated in a short heating cycle, we evaluated the temperature tolerance of these two fungi in Douglas-fir heartwood blocks. These tests indicated that both fungi were eliminated by exposure to temperatures above 71°C for over 1 hour or 60°C for 2 hours. The results suggest that careful control of temperature during treatment should eliminate decay fungi and that wood treated at ambient temperatures should be heated to kill fungi that become established during air-seasoning. vii This past year was the third and final year of the decay development study. In this study, sterile pole sections have been exposed for 1, 2, or 3 years at widely scattered Pacific Northwest sites, then returned to the laboratory and extensively sampled. We are now in the process of identifying the fungi from the third year poles. In addition to examining poles prior to preservative treatment, we are also evaluating poles treated with waterborne chemicals (ACA or CCA) for the incidence of surface decay. This past year we examined twenty ACA-treated poles from a line installed in 1946. While a variety of fungi were cultured from the wood, none of the poles had evidence of substantial surface deterioration. A study was initiated on the fungal flora of fumigant treated wood because of the potential for fungi developing resistance to low levels of fumigant or the ability to actively degrade the chemical. Both of these developments could shorten fumigant retreatment cycles and increase maintenance costs. We have evaluated poles treated 7 and 15 years ago with fumigants and find markedly reduced fungal flora. Tests are continuing on the fungi isolated, and we hope to assess the effects of these isolates on long-term fumigant effectiveness.
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Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range ...
Citation Citation
- Title:
- Investigations of Larval Pacific Lamprey Entosphenus tridentatus Osmotic Stress Tolerance and Occurrence in a Tidally-Influenced Estuarine Stream
- Author:
- Silver, Gregory Shell
- Year:
- 2015
Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range and reductions in Pacific lamprey abundance have been observed in Western North America, and may be indicators of range-wide declines. In the face of declining populations, the U.S. Fish and Wildlife Service has partnered with tribal, state, federal, and local entities to implement a regional Pacific lamprey conservation agreement aimed at reducing threats to Pacific lamprey and improving their habitats and population status. Research needs identified in the conservation agreement include assessing larval Pacific lamprey occupancy and distribution, habitat requirements, and the limiting factors of larval distribution in the freshwater ecosystem. As part of the effort to address these knowledge gaps, we investigated the potential for larval lampreys to occur in tidally-influenced estuarine environments. Research of this type may be valuable for future conservation, management or recovery efforts of Pacific lamprey throughout its range. We employed a two-phased approach, consisting of laboratory and field components to address our aims. We first conducted a series of controlled laboratory experiments to evaluate osmotic stress tolerance and osmoregulatory status of larval Pacific lamprey exposed to a range of (1) fixed salinity in various dilutions of saltwater and (2) oscillating salinity treatments designed to simulate tidal activity. Tolerance was assessed by monitoring and comparing survival of larvae in various treatments through 96 h. Osmoregulatory status was assessed by quantifying and comparing total body water content, plasma osmolality, and plasma cation (i.e., sodium) concentrations among larvae surviving various treatments. In fixed salinity experiments, 100% survival was observed in 0‰, 6‰, 8‰ and 10‰ through 96 h, while 0% survival was observed through 48 h in 12‰, 30 h in 15‰, and 12 h in 25‰ and 35‰. In oscillating salinity experiments, on the other hand, a significant increase in survival (100%) was observed through 96 h in treatments that oscillated between 12‰ and 0‰ (freshwater) at about 6 h intervals versus fixed 12‰ salinity experiments. A significant increase in survival also occurred in oscillating 15‰ treatments (60%) versus fixed 15‰ through 96 h. Linear regression analysis indicated higher environmental salinity in laboratory experiments was significantly related to increases in plasma osmolality and plasma sodium (the most abundant osmotically active plasma cation) concentrations, and concurrent decreases in total body water content among larvae that survived various treatments. Tidal oscillations in salinity appeared to temper the desiccating effects of salinity, as changes in body water content and sodium ion concentration were less abrupt than fixed salinity treatments. These results suggest larvae cannot osmoregulate in hyperosmotic environments, but are able to tolerate some fixed and oscillating hyperosmotic salinity exposure. Consequently, larvae may be able to occur in certain areas of estuaries, such as oligohaline habitats that are characterized by low levels of salinity. Experimental results were used, in part, to guide larval sampling in a tidally-influenced habitat. Occurrence of larval Pacific lamprey and Lampetra spp. (western brook and river lampreys) was subsequently investigated across a gradient of salinity in Ellsworth Creek (Pacific County, Washington) by electrofishing. Larval Pacific and Lampetra spp. were detected within an approximately 300 m long tidally-influenced segment of the study area. Salinity monitoring was conducted in six tidally-influenced reaches where larvae were detected for up to 14 d following electrofishing. Maximum tidal cycle salinity exceeded 15 ppt during 52% to 80% of tidal cycles within tidally-influenced reaches where larvae were detected. These results suggest potential for larval lamprey to occur in certain portions of tidal estuaries. However, long-term residence of larvae in tidally-influenced habitats and whether larvae are able to subsequently survive, grow, transform, and out-migrate is not known and requires further study. Given the potential for tidally-influenced habitats to be occupied by larvae, assessments of larval occurrence in other areas, such as the lower Columbia River, may be warranted. Knowledge of larval lamprey distribution in estuarine environments may be valuable for habitat restoration, and mitigating potential impacts from dredging and other human disturbances.