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The purpose of this study was to understand the influence of organic material and nutrients from spawning salmon and supplemented salmon carcasses on stream food webs. My study objectives were to examine ...
Citation Citation
- Title:
- Salmon and marine-derived nutrient effects on primary and secondary trophic levels
- Author:
- Claeson, Shannon M.
The purpose of this study was to understand the influence of organic material and nutrients from spawning salmon and supplemented salmon carcasses on stream food webs. My study objectives were to examine 1) assimilation of salmon-derived nutrients (SDN) by producers and consumers in the food web, 2) epilithic biofilm productivity, 3) leaf-litter decomposition rates, and 4) benthic insect density and biomass, in areas with and without spawning salmon and also compare these responses downstream and upstream of salmon carcasses. My hypothesis was that production-related measures of organisms that assimilate SDN would increase in response to spawning salmon or added carcasses. Biofilm, leaf-litter, and macroinvertebrate responses to salmon were evaluated during two field studies in the Wind River basin of southwest Washington. The first study (July - November 2002) was observational and compared responses from a reach with spawning Chinook (Onchorhychus tshawytscha) to two reaches upstream of spawning salmon. In the second experiment (July - October 2003), Chinook carcasses were added and retained within three streams in which responses were measured at increasing distances downstream of the salmon (10m, 50m, 150m, and 250m) and compared to responses measured upstream of salmon. Analysis of stable carbon and nitrogen isotopes demonstrated that SDN from both naturally spawned salmon and manually added carcasses were incorporated into the stream food webs by epilithic biofilm, most benthic insects (scrapers, collectors, and predators), and juvenile steelhead. However, I was unable to detect changes in primary and secondary production-related measures in response to naturally spawned salmon. This observational study was limited in its design and the carcass-addition experiment in the second year provided greater resolution about secondary consumers and spatially explicit responses. Results from the carcass-addition study showed a non-significant increase in epilithic biofilm chlorophyll a levels in October, but no effect on biofilm ash-free-dry-mass. Leaf decomposition rates in September were significantly faster at one site downstream of added carcasses, but shredding insects did not increase in density or biomass, and shredders did not assimilate SDN. Of the nutrients measured (NH⁴-N, NO³-N, NO²-N, DON, SRP, DOC), only ammonium increased significantly downstream of added carcasses. Total benthic insect density significantly increased in September whereas total insect biomass was highly variable and no changes were detected. Densities and/or biomass of some scraping (Heptageniidae) and collecting (Chironomidae and Elmidae) benthic insects increased in September and/or October. Predatory insects did not increase in density or biomass, though they did assimilate SDN. These results suggest a potential bottom-up cascade in which increased primary production was reduced by an increase in secondary consumers. In general, benthic responses were highest within 50 m downstream of added carcasses. Salmon-derived nitrogen was observed in epilithic biofilm and some benthic insects collected 150 m downstream of carcasses. The timing of responses varied depending on the mode of consumption. In limnephiled caddis larvae colonizing carcasses, the SDN signal peaked just 2 weeks after carcasses were added. Among insects that indirectly consumed SDN, the signal peaked 2 months post-carcass addition. Benthic insect production peaked 1.5 months after carcasses were added, with most measures returning to background levels one month later. Augmenting streams with salmon carcasses may influence several ecosystem components, but responses may be spatially localized around carcasses and persist for only a short time after carcasses are added.
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432. [Article] A food web analysis of a Mojave Desert geothermal spring system and feeding ecology of Moapa dace (Moapa coriacea)
Understanding food webs is fundamental in conserving endangered species and maintaining healthy ecosystem function, particularly in desert spring systems. We identified dominant energy sources in the ...Citation Citation
- Title:
- A food web analysis of a Mojave Desert geothermal spring system and feeding ecology of Moapa dace (Moapa coriacea)
- Author:
- St Saviour, Adam
Understanding food webs is fundamental in conserving endangered species and maintaining healthy ecosystem function, particularly in desert spring systems. We identified dominant energy sources in the Muddy River Warm Springs area, Clark County, NV using carbon and nitrogen natural abundance stable isotope analyses. We examined isotopic signatures of specific macroinvertebrate food resources for the endangered, drift-feeding Moapa dace (Moapa coriacea) and looked for changes in isotopic ratios over the stream gradient. Our results indicate the Muddy River Warm Springs area is supported primarily by allochthonous energy sources, and Moapa dace did not focus on specific macroinvertebrate taxa. We characterized a pattern of downstream δ¹³C enrichment, which is seemingly common in groundwater-fed systems but discussed very little in the literature. We conclude that ground water carbon of marine origin, heterotrophic respiration, and fractionation and depletion of the δ¹³C pool by autotrophs contribute to a wide range δ¹³C values in primary producers and to the downstream enrichment pattern in the Muddy River Warm Springs. We then quantified macroinvertebrate drift throughout the Moapa dace's current and historic range within the Muddy River Warm Springs. We examined the relationship of total drift biomass and temperature and associations between specific macroinvertebrate orders and Moapa dace abundance. We also explored habitat characteristics associated with Moapa dace and their prey. In 2008 and 2009, total drift biomass/time and the biomass of most orders was negatively correlated with temperature and positively correlated with discharge. Only Lepidoptera and Neotaenioglossa had positive associations with temperature in 2008. In 2009, total biomass/volume had a negative linear relationship with temperature and a positive linear relationship with discharge, though these relationships were absent in 2008. Moapa dace were associated with high temperatures, low stream discharge, shallow depth, and low drift biomass both years. They were positively associated with thermally tolerant Lepidoptera and Neotaenioglossa in 2008 and no orders in 2009. Macroinvertebrate drift may be greater in cooler, downstream reaches because temperatures in those reaches are favorable to more taxa, there is more cumulative benthic area contributing to production, and there are fewer drift feeding insectivores. Lastly, we examined Moapa dace feeding flexibility by experimentally manipulating drift (0, 34, 64, 100, and 200% of the natural drift level) and quantified their feeding attempts and success. We found that Moapa dace are obligate drift feeders, selecting drift 40 times more frequently than benthos. They did not adaptively shift foraging modes from drift to benthic when drift was experimentally reduced. Drift feeding rate increased in response to increasing drift, but drift feeding success only increased from the 0% to the 64% drift level and did not change in the 100% and 200% levels. No relationship between fish size or food availability and aggression was detected. Moapa dace may share an interspecific foraging association with sympatric White River springfish (Crenichthys baileyi). Moapa dace are currently excluded from lower, more productive reaches by invasive species and fish barriers. Maintaining spring flows, eradicating non-natives, and restoring system connectivity will likely benefit Moapa dace and other Muddy River Warm Springs endemics.
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433. [Article] The effects of harvesting Pacific hake (Merluccius productus) on the offshore community : the results of a multi-species model
The effects of harvesting Pacific hake (Merluccius productus) were examined with a multi-species numerical model composed of seven logistic growth equations coupled by a food web. The food web was composed ...Citation Citation
- Title:
- The effects of harvesting Pacific hake (Merluccius productus) on the offshore community : the results of a multi-species model
- Author:
- Gartz, Russell G.
The effects of harvesting Pacific hake (Merluccius productus) were examined with a multi-species numerical model composed of seven logistic growth equations coupled by a food web. The food web was composed of: California sea lions (Zalophus californianus), hake, sablefish (Anaplopoma fimbria), spiny dogfish (Squalus acanthias), a generic rockfish species (Sebastes spp.), Northern anchovy (Engraulis mordax), and a generic euphausiid species (as an example, Pacific krill, Euphausia pacifica). The model was tuned to mimic stock assessment biomass estimates for the years 1980 to 1991, after which a short term experiment and a sensitivity analysis were conducted. The short term experiment used a factorial design, with hake fishing and fishing for rockfish, sablefish, and anchovy as treatments. It was analyzed with scale analysis techniques. The results indicate that hake (from a management viewpoint) is potentially most important in the offshore community as a prey item for sea lions and as a predator on anchovies, but hake fishing mortality had a small effect on either population during the time span of the experiment. Results also suggest that hake has little or no competitive interaction with other species that are trophically similar. Increased harvesting of hake would probably do little to increase the biomass of rockfish or sablefish. The general conclusion of both the sensitivity analysis and the experiment is that species below their carrying capacity are mostly affected by changes in growth and removal processes while species close to their carrying capacity are mostly affected by processes controlling prey availability. A forty year projection from 1991 to 2031 was conducted to examine the effects of hake fishing on sea lion and anchovy biomass. Results indicate that sea lion biomass will vary inversely with hake fishing effort, while anchovy biomass is directly proportional to hake fishing effort. Results also indicate that hake experience environmental conditions not favorable to recruitment. During favorable conditions the hake population builds up a "surplus" that carries it through periods of unfavorable conditions. Increased hake fishing effort reduces the response of the population to favorable conditions. The results of this research constitute a step from the theory toward the practice of proactive multi-species and ecosystem management.
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Nehalem Bay is located on the northern coast of Oregon in Tillamook County and contains approximately 243 ha of salt marsh. The Nehalem marshes occur as islands and land-tied units. West Island is the ...
Citation Citation
- Title:
- Plants, plant communities, net production and tide levels; the ecological biogeography of the Nehalem salt marshes, Tillamook County, Oregon
- Author:
- Eilers, H. Peter
Nehalem Bay is located on the northern coast of Oregon in Tillamook County and contains approximately 243 ha of salt marsh. The Nehalem marshes occur as islands and land-tied units. West Island is the largest marsh island with an area of 82.9 ha and a maximum elevation of 3.079 m above mean lower low water. Three divisions on West Island based on inundation period have been identified: intertidal marsh, below mean high water; transitional marsh, from MHW to 2.76 m above MLLW; and extratidal marsh, above 2.76 m. West Island may be further subdivided into four topographic units based on the steepness of the elevation gradient: edge marsh, from.the lower margin to 2.00 m; low marsh, 2.00 to 2.36 m; transitional marsh, 2.36 to 2.76 m; and high marsh, 2.76 m and above. Creek density is low for the lower intertidal marsh, for the edge marsh, and.for the higher extratidal marsh; and is high for the upper intertidal and transitional marsh. Salt marsh vegetation-on West Island was sampled by harvesting aboveground biomass along seven transects at two-month intervals from May of 1972 to September of 1972. Plant species diversity increases with elevation and each species displays a particular elevation range. Analysis of dry-weight data by an ordination routine suggests the presence of 11 plant communities along the elevation gradient on West Island. Plant communities named by dominant species are Triglochin, Scirpus, Carex (tall and short phases), Carex-Deschampsia-Triglochin, Triglochin-Deschampsia, Carex-Deschampsia-Triglochin-Agrostis, Juncus- Agrostis, Juncus-Agrostis-Festuca, Aster-Potentilla-Oenanthe, Carex- Aster-Oenanthe, and Picea-Salix. Plant communities are readily identified by signatures on aerial photographs. Net aerial production on West Island increases with elevation and varies from a minimum of 518 g/m2/yr for the Triglochin community to a maximum of 1936 g/m2/yr for the Aster-Potentilla-Oenanthe community. The community mean net aerial productivity is 1388 g/m2/yr. More than 90 percent of the intertidal marsh net aerial production is removed to the estuary as organic detritus, and net aerial production in the high marsh is rapidly incorporated into marsh soil. It is estimated that approximately 56 percent of all net aerial production on West Island is transported to the estuary by the tides. It is recommended that salt marshes be preserved in their natural state and new salt marshes be created to ensure the continued high productivity of estuarine ecosystems in Oregon.
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Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, ...
Citation Citation
- Title:
- Blue-Green Consumption: Determinants for Eco-Labelled Seafood Purchasing in Sweden
- Author:
- Rönnbäck, Patrik, Jonell, Malin, Troell, Max, Crona, Beatrice
- Year:
- 2016
Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, July 11-15, 2016. Compiled by Stefani J. Evers and Ann L. Shriver. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016.
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This report and accompanying program inventory have been prepared in support of the Oregon Department of Environmental Quality's statewide nonpoint source pollution control efforts and for use in the development ...
Citation Citation
- Title:
- Non-regulatory efforts to combat nonpoint source pollution in Oregon
- Author:
- Lindberg, Roberta J.
This report and accompanying program inventory have been prepared in support of the Oregon Department of Environmental Quality's statewide nonpoint source pollution control efforts and for use in the development of Oregon's new federally mandated Coastal Nonpoint Pollution Control Program (CNPCP). When Congress reauthorized the Coastal Zone Management Act in 1990, it added significant new responsibilities for coastal states regarding water pollution from diffuse, widespread sources that in the past have not been regulated. Section 6217 of the Coastal Zone Act Reauthorization Amendments (CZARA) requires states to adopt enforceable programs to address nonpoint source pollution arising from agriculture, forestry, urban runoff, recreational boating and marinas, channelization, dams and eroding stream banks. "Nonpoint source pollution" in this context includes any discharge to the state's waters which is not regulated by the Clean Water Act's permit system, the National Pollutant Discharge Elimination System (NPDES). When Congress mandated the coastal nonpoint source program, it directed that states' coastal programs and water quality agencies work together in developing and implementing the program. In Oregon, the Department of Land Conservation and Development (DLCD) and the Department of Environmental Quality (DEQ) are jointly responsible for the development of the coastal nonpoint control program. DLCD's Coastal Management Program implements provisions of the federal Coastal Zone Management Act. DEQ's Water Quality Division manages the statewide nonpoint source control program pursuant to Section 319 of the Clean Water Act (CWA). Staff at DLCD's Coastal Management Program prepared an extensive report and analysis of Oregon's current array of enforceable programs and the extent to which those programs satisfy the federal requirements for the new coastal program. Gaps in program coverage were identified, and efforts to fill those gaps are currently in progress. This report is a companion to the DLCD gap analysis. However, instead of focusing on enforceable programs, this report highlights nonpoint source control and watershed management programs that rely on voluntary efforts to achieve their goals. Staff at DEQ have identified nine types of activities which, together with enforcement, make constitute an effective watershed management program. This report presents an inventory of the state and federal government efforts currently underway within the state of Oregon which contribute to the control of nonpoint source pollution but do not rely on a regulatory program to do so. This is a time of extensive reevaluation and reordering of natural resource priorities and strategies at both the state and federal levels. The Clinton Forest Summit and the Forest Ecosystem Management Assessment Team (FEMAT) process have been examining federal forest policy from top to bottom. The two major federal land management agencies, the Forest Service and the Bureau of Land Management, began reviewing their policies and practices well before the Forest Summit, and have made significant changes as a result. At the state level, the Watershed Health Initiative directed $10 million to two regions of the state during the 1993-95 biennium, in an unprecedented effort to restore salmon habitat and improve water quality. The impetus for change comes from the visible results of past natural resource management practices: the collapse of many native salmon runs and the decline in many other species leading to a great expansion of activity under the federal Endangered Species Act. The federal court logging injunction to protect the Northern Spotted Owl triggered much activity at the state and local levels in an effort to avoid further listings and the potential economic dislocations associated with them.
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In a January 26, 2000 letter, the Portland District Army Corps of Engineers (COE) requested Endangered Species Act (ESA) Section 7 informal consultation with the National Marine Fisheries Service (NMFS) ...
Citation Citation
- Title:
- Effects of Construction of an Infiltration Gallery Water Intake (Permit ID No. 00-32) on Cow Creek on Umpqua River Cutthroat Trout and Oregon Coast Coho Salmon : Biological Opinion
In a January 26, 2000 letter, the Portland District Army Corps of Engineers (COE) requested Endangered Species Act (ESA) Section 7 informal consultation with the National Marine Fisheries Service (NMFS) on the proposed issuance of a Clean Water Act Section 404 permit (Permit ID No. 00-32) to allow an instream construction project. The applicant for this permit, the City of Glendale (City) proposes to construct an infiltration gallery-type municipal water intake in Cow Creek, a tributary of the South Umpqua River in Douglas County, Oregon. The new water intake, which would be buried beneath the bed of the creek, would replace an existing screened intake in the creek which has deteriorated and which is thought to have insufficient capacity. The COE has proposed conditions on the permit that would lessen the adverse effects of the proposed actions on aquatic organisms. In the January 26 letter, the COE determined that the Umpqua River (UR) cutthroat trout (Oncorhynchus clarki), listed as endangered under the ESA, and Oregon Coast (OC) coho salmon (O. kisutch), listed as threatened under the ESA, may occur within the project area, which has been proposed as critical habitat for these species. The COE also determined that these species may be affected by the proposed projects, but that individuals of the species would not be adversely affected. After review of the information provided by the COE and additional investigation, however, the NMFS concluded that more than a negligible likelihood of adverse effect to individuals of the listed species is likely because substantial in-water work is proposed during a period in which individuals of one or both species is likely to occur at and near the site. Based on this information, the COE agreed to modify its effect determination to likely to adversely affect.
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My thesis explored the effects of and potential mediating mechanisms for an important environmental stressor, ultraviolet-B (UVB) radiation. UVB radiation has negative effects on organisms in both terrestrial ...
Citation Citation
- Title:
- Ultraviolet radiation as an environmental stressor of amphibians
- Author:
- Bancroft, Betsy A.
My thesis explored the effects of and potential mediating mechanisms for an important environmental stressor, ultraviolet-B (UVB) radiation. UVB radiation has negative effects on organisms in both terrestrial and aquatic systems. I used meta-analysis to quantify the effects of UVB radiation on a diversity of aquatic organisms (Chapter 2). UVB negatively affects aquatic organisms by reducing both survival and growth. In particular, UVB reduces growth of embryos more than any other life history stage. Some taxonomic groups may be more affected by UVB radiation than others. In our analysis, the growth of members of the kingdom Protozoa was suppressed by UVB radiation to a greater degree than any other kingdom. These analyses suggest that UVB is an important stressor in both freshwater and marine systems. Amphibians are a common component of freshwater systems and are experiencing world-wide population declines. These declines may be due to a number of causes including habitat loss, introduced species, global climate change, disease, toxic chemicals and UVB radiation. I used meta-analytic techniques to quantify the effects of UVB radiation on amphibians. By synthesizing the results of 41 articles on the effects of UVB radiation on amphibians (Chapter 3), I found a nearly 2-fold reduction in survival of amphibians exposed to UVB radiation. Salamanders (caudates) appear to be more susceptible to damage from UVB than frogs or toads (anurans). Moreover, survival of larvae was much lower than survival of embryos or metamorphic individuals under UVB radiation. In addition, I used factorial meta-analytic techniques to explore the interaction between UVB radiation and other stressors in amphibian habitats. UVB radiation acted synergistically with other stressors to reduce survival of amphibians. Behavioral avoidance of UVB radiation may help mediate the negative effects of UVB radiation on amphibians. In aquatic systems, behavioral avoidance usually requires movement out of shallow water, where UVB levels can be high, into deeper waters with lower UVB transmittance. However, these two microhabitats have very different thermal profiles, creating a trade-off between exploiting warm waters with high UVB levels and avoiding UVB by seeking cooler, deeper regions of ponds. I explored the microhabitat use of larvae of four species through a series of laboratory experiments, field experiments, and observational field transects at three different amphibian habitats (Chapter 4). Larvae did not avoid UVB radiation in either the laboratory or field experiments. Larvae in thermal gradients selected relatively high temperatures regardless of the UVB exposure at these temperatures. In field transects, salamander larvae were most common in deeper, cooler waters where UVB levels were lower. In contrast, anuran larvae were frequently observed in the warmer and shallower regions of each habitat. These regions also had the highest UVB levels, suggesting that anuran larvae are exposed to high levels of UVB due to thermoregulatory behavior. Behavioral avoidance of UVB radiation is not the only mechanism amphibians may use to prevent damage from UVB. Pigments such as melanin may allow larvae to exploit warm shallow waters by absorbing harmful UVB radiation before it causes cellular damage. I tested the efficacy of melanin as a photoprotective pigment in the larvae of two species, Rana cascadae and Pseudacris regilla (Chapter 5). I found no evidence of a photoprotective function for melanin in these larvae. In contrast, lighter colored tadpoles grew more under UVB radiation compared to darker colored tadpoles. Overall, exposure to UVB reduced survival of P. regilla larvae and reduced growth of R. cascadae larvae. Larvae of both of these species were frequently observed in very shallow water with intense solar radiation. This thesis emphasizes the importance of UVB radiation as an environmental stressor in aquatic habitats. Many aquatic organisms are negatively affected by UVB exposure. My thesis work quantitatively demonstrated that UVB radiation is one factor that reduces survival of amphibians and suggests that some species are exposed to high levels of UVB radiation in natural habitats. While UVB radiation is not the sole cause of amphibian population declines, my work suggests that UVB radiation is an important stressor for amphibians that should not be overlooked. In addition, UVB radiation is clearly an important stressor for many other aquatic organisms. Future work should consider the effects of UVB in aquatic systems, particularly the effects of UVB radiation on community structure and ecosystem function.
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439. [Article] Recovery of Wild Coho Salmon in Salmon River Basin, 2008 Report Number: OPSW-ODFW-2009-10
Abstract -- Recovery and conservation of naturally self-sustaining salmon populations is a central goal of the Oregon Plan for Salmon and Watersheds. In 1998, the Oregon Department of Fish and Wildlife ...Citation Citation
- Title:
- Recovery of Wild Coho Salmon in Salmon River Basin, 2008 Report Number: OPSW-ODFW-2009-10
Abstract -- Recovery and conservation of naturally self-sustaining salmon populations is a central goal of the Oregon Plan for Salmon and Watersheds. In 1998, the Oregon Department of Fish and Wildlife (ODFW) initiated a comprehensive program to monitor the status of coho salmon (Oncorhynchus kisutch) populations and aquatic habitat in coastal drainages of Oregon (OWEB 2003). A 2005 assessment by ODFW concluded that Oregon coastal coho were viable at the scale of the Evolutionary Significant Unit (ESU) and demonstrated resilience in response to improving ocean conditions. Yet 7 of 21 (33%) individual populations within the ESU failed one or more of five criteria used to assess viability (Chilcote et al. 2005), and it is uncertain whether productivity levels across the ESU will recover sufficiently to withstand future periods of poor ocean conditions. The coho population in Salmon River was the only population in the ESU to fail all five viability criteria. Uncertainty remains about the response of Oregon coastal coho salmon to different combinations of freshwater and marine limiting factors, complicating recovery efforts (Lawson 1993; Lawson et al. 2004; IMST 2006). Such uncertainty cannot be resolved entirely by existing Oregon Plan monitoring programs, which target only a portion of the habitats and coho salmon life stages in large river basins, and with few exceptions (e.g., Johnson et al. 2005), were not designed to test population responses to individual management manipulations. In 2007, in response to the failure of viability criteria, ODFW managers discontinued releases of hatchery coho salmon into Salmon River as one of the primary management actions under the Oregon Conservation Plan for the Oregon Coast Coho Evolutionarily Significant Unit (hereafter “coho plan,” Nicholas 2006). This change affords the first opportunity in Oregon to monitor the results of a large scale experiment in removing hatchery coho salmon from a basin for at least four generations (twelve years). Hatchery production has been a centerpiece of salmon management for decades, but rarely has full recovery from hatchery influence been given a chance to succeed. Salmon River offers a test basin to explore whether an independent population of coho salmon can recover from a prolonged period of very low abundance following removal of the primary factor limiting productivity. Here we describe the first year of a study to monitor the dynamics of the coho salmon population in the Salmon River basin on the central Oregon coast and to determine whether management changes targeting both hatchery influence and stream habitat complexity improve population viability. This research will validate assumptions about factors limiting coho recovery and determine whether recovery measures proposed by the Coho Plan have been effective. Our research is designed to document changes in population abundance, distribution, and life history structure of coho salmon following the removal of hatchery coho salmon from the watershed. It integrates adult, juvenile, and habitat components to establish links and describe variability between juvenile performance and adult recovery. It also monitors the coho salmon population across habitat types and life history stages to identify population responses at a landscape scale. We will establish the link between productivity and survival at each salmon life stage and recovery of the adult population. From these indicators, we will determine the potential resiliency of coho salmon, detail the biological benefits/tradeoffs of returning the ecosystem to natural salmon production, and assess whether supplementation should remain an option in Salmon River. As a conceptual framework, our research design and analyses are guided by the “viable salmonid population” criteria identified by McElhany (2000) and modified by Chilcote et al. (2005) and Nicholas (2006), including abundance, productivity, distribution, diversity, and habitat quality. The results of our new research will be integrated with habitat survey and adult population data collected under the existing Oregon Plan monitoring program and coho salmon population and life history data available from previous Salmon River surveys (Mullen 1978, 1979; Cornwell et al. 2001; Bottom et al 2005; Volk et al. in review). Together these data will address four principal objectives: 1. Quantify viability of the coho salmon population before and after hatchery coho salmon are removed from Salmon River. 2. Assess whether viability of the Salmon River coho population is limited by quantity and complexity of stream habitat. 3. Describe the diversity of juvenile and adult life histories of coho salmon in the Salmon River basin and estimate the relative contributions of alternate juvenile life history to adult returns. 4. Determine salmonid use and benefits of restored tidal wetlands before and after hatchery coho salmon are removed from Salmon River. By synthesizing historic data with new information for the Salmon River basin, we will compare population structure during three distinct periods – pre-hatchery (1974-77), hatchery (1990-2008), and post-hatchery (2009-2013). This annual report discusses the activities and findings from 2008, the first year of the multi-year project, including coho salmon distribution and abundance on the Salmon River spawning grounds, juvenile abundance and distribution in the watershed and estuary, migration timing, and life history diversity.
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This document is the 1998 annual progress report for studies of Pacific lampreys (Lampetra tridentata) conducted by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), Columbia River Inter-Tribal ...
Citation Citation
- Title:
- Pacific lamprey research and restoration project : annual report 1998
- Author:
- Close, David A.
This document is the 1998 annual progress report for studies of Pacific lampreys (Lampetra tridentata) conducted by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), Columbia River Inter-Tribal Fish Commission, and University of Minnesota (U of M). Bonneville Power Administration (BPA) funded activities through Project 94-026. The Pacific Lamprey Research and Restoration Project began after completion of a status report of Pacific lamprey in the Columbia River in 1995. The project started as a cooperative effort between the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), Columbia River Inter-Tribal Fish Commission (CRITFC), and Oregon State University (OSU). Lamprey are a valuable subsistence food and cultural resource for Native Americans of the Pacific Northwest. The once abundant Pacific lampreys above Bonneville Dam are currently depressed (Close et al. 1995). Declines in Pacific lampreys have impacted treaty secured fishing opportunities by limiting tribal members catch and access to Pacific lampreys in the interior Columbia basin. Tribal members now harvest lampreys in lower Columbia River locations such as Willamette Falls near Oregon City, Oregon. Pacific lampreys are also an important part of the food web of North Pacific ecosystems, both as predator (Beamish 1980; Pike 1951; Roos and Gillohousin 1973), and prey (Semekula and Larkin 1968; Galbreath 1979; Roffe and Mate 1984; Merrell 1959; Wolf and Jones 1989) and as a vehicle for recruitment of marine nutrients. The decline of Pacific lampreys in the interior Columbia River basin has become a major concern. Effective recovery measures for Pacific lampreys can only be developed after we increase our knowledge of the biology and factors that are limiting the various life history stages. Prior to developing a restoration plan, we have carried out studies to review status, distribution, abundance, homing ability, and stock structure. These studies will culminate in the development and implementation of a restoration plan for the Umatilla River. Multiple pass electrofishing surveys to assess densities and distribution of lamprey larvae in the Umatilla River were conducted in 1998. Electrofishing surveys in the Umatilla River are useful for baseline comparison. Forty-two index sites were sampled from the mouth to river kilometer (RK) 124. Lamprey larvae were found in 4 of the 42 index plots. All sites with larvae were found at and below RK 9.3. Nine larvae were captured during the surveys. However, no larvae were caught on the second pass in each plot. Pacific lamprey larvae and adult lampreys were studied to determine their ability to produce and detect pheromones. Larval gall bladders were removed and gall bladder fluid was extracted and analyzed by high performance liquid chromatography (HPLC). Adult lampreys ability to detect pheromones were tested using electro-olfactogram (EOG) methods. Fifteen compounds including Petromyzonol sulfate (PS), a migratory pheromone found in sea lamprey larvae (Petromyzon marinus) (Li et al. 1995) were tested. Larval lampreys produced large amounts of (PS). Adult Pacific lamprey can detect PS and have an olfactory sensitivity to pheromones that is similar to sea lampreys. iv Pacific lamprey abundance, as indexed by fish ladder counts in 1998, was; Bonneville 37,478; The Dalles 7,665; John Day 12,579; McNary 3,393; Ice Harbor 763; Lower Monumental 69; Little Goose 90; Lower Granite 110; Rock Island 1,410; and Rock Reach 819 dams, respectively. Enumerating Pacific lamprey at counting stations remained extremely problematic, since excessive up- and downstream movement at the counting windows reduces the confidence in fish ladder passage estimates. This may be an indication of passage problems encountered by Pacific lampreys. In-season homing of Pacific lamprey was studied using radio telemetry. Pacific lampery were captured at Willamette Falls and Bonneville Dam, outfitted with radio transmitters and released approximately 26 km downstream of the Willamette River confluence. A total of 50 fish were instrumented. Results will be presented in next year’s report. Natal homing was also investigated using mtDNA analysis of fish captured at Bonneville Dam and from Willamette Falls. These results will also be presented next year. We collected lamprey tissues, from fish captured in several locations throughout the Columbia River Basin, to develop a genetic database for use in determining population structure. Additional samples for populations outside the Columbia River Basin were used to scale the results. Results from this investigation will be presented in next year’s annual report. Since the initiation of the CTUIR lamprey research and restoration project, additional lamprey studies have been proposed that have created uncertainties regarding the prioritization of projects and needs of lampreys. At the request of the Northwest Power Planning Council, a multi-agency Pacific lamprey technical workgroup (TWG) was established in 1996. Annual meetings are held to coordinate projects and prioritize research needs. The TWG identified critical uncertainties and needs to help in determining priorities of ongoing and proposed projects (Appendix A). Finally, an annotated bibliography of relevant lamprey literature was compiled (Appendix B).