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441. [Article] Status and Distribution of Native Fishes in the Goose Lake Basin Information Reports number 2008-02
Abstract -- This study describes the current distribution of the nine native fish species in the Oregon portion of the Goose Lake basin (Lake County): Goose Lake redband trout Oncorhynchus mykiss ssp., ...Citation Citation
- Title:
- Status and Distribution of Native Fishes in the Goose Lake Basin Information Reports number 2008-02
Abstract -- This study describes the current distribution of the nine native fish species in the Oregon portion of the Goose Lake basin (Lake County): Goose Lake redband trout Oncorhynchus mykiss ssp., Goose Lake lamprey Entosphenus sp., Goose Lake tui chub Siphateles bicolor thalassinus, Goose Lake sucker Catostomus occidentalis lacusanserinus, Modoc sucker Catostomus microps, Pit-Klamath brook lamprey Entosphenus lethophagus, speckled dace Rhinichthys osculus, Pit roach Lavinia symmetricus mitrulus, and Pit sculpin Cottus pitensis. The Goose Lake basin is an endorheic, or topographically closed basin located in south central Oregon and northeastern California. The basin is within the usually closed northeastern extremity of the adjoining Sacramento River basin, astride the Oregon-California boundary. Although most of the lake lies in California, most of its valley and nearly two-thirds of the total drainage area (~722 sq. mi.) are in Oregon. The largest streams in the basin are Drews, Cottonwood, and Thomas Creeks. Annual precipitation averages about 36 cm per year (Phillips and van Denburgh 1971). Goose Lake overflowed briefly into the North Fork Pit River in 1868 and 1881, but storage and diversion of irrigation water has substantially reduced the inflow and future overflow is unlikely (USGS 1971). The lakebed was dry in the summers of 1926, 1929- 1934, and 1992. About half the basin is forestland, 20% is hay fields and pastureland, and 16% is shrub and rangeland. Currently, almost 35% of the inflow is diverted for irrigation (OWRD 1989). The Goose Lake basin is home to four endemic fish taxa: the Goose Lake redband trout, lamprey, sucker, and tui chub. Endemic fishes of the Goose Lake basin split their life histories between Goose Lake and its tributaries, as opposed to the five native but non-endemic species that primarily occupy stream habitats. Pit roach and all endemic fishes except Goose Lake tui chub are listed as a “species of concern” by the USFWS, a designation that implies there is concern about species viability, but not enough information is known to initiate a listing review for threatened or endangered status. The Modoc sucker was listed as a federally endangered species in 1985 (USFWS 1985). No formal recovery plan was required due to an existing “Action Plan for the Recovery of the Modoc Sucker” (USFWS 1984). Most of the recovery actions outlined in the action plan were either completed or are no longer relevant (Stewart Reid, Western Fishes, personal communication). However, actions 26 and 27 pertaining to range expansion remain incomplete. Action 26 suggests reclassification to threatened upon establishment of safe populations (for 3-5 years) throughout the Rush and Turner Creek watersheds in the Pit River basin. Action 27 suggests delisting upon establishing safe populations in two other historic streams. At the time of listing, the historic range of Modoc sucker was thought to have included only two small tributaries of the Pit River in Modoc and Lassen Counties, Ash and Turner Creeks (USFWS 1985). Therefore, a major recovery goal was to expand the species’ range with additional populations (USFWS 1984). In 2001, reexamination of historical documents and museum specimens established that Modoc suckers had also historically occupied Thomas Creek in the Goose Lake basin. Field collections in 2001, with subsequent morphological and genetic analysis, confirmed that the population was still present in Thomas Creek (Stewart Reid, Western Fishes, personal communication); however, the broader range of Modoc sucker in the Goose Lake watershed was not known. In 1995, the Goose Lake Fishes Working Group drafted a conservation plan for “prelisting” recovery of all native fish in response to severe drought and habitat degradation (GLFWG 1995). The Aquatic Inventories Project of the Oregon Department of Fish and Wildlife (ODFW) conducted habitat and fish distribution surveys (1991-1995) to obtain baseline information to help inform recovery efforts (ODFW, unpublished data). Since then, field work to monitor the distribution and abundance of Goose Lake fishes has been limited and sporadic, targeting only Goose Lake redband trout and Modoc sucker (Dambacher 2001; Reid 2007). No comprehensive follow up work has been conducted to evaluate fish response to climatic conditions, habitat restoration projects, and continued irrigation activities. ODFW recently drafted a status review of native fish of Oregon (ODFW 2005). Except for redband trout, Goose Lake fishes were not included in the status review due to a lack of new information since the previous status review in 1995 (Kostow et al. 1995). Further, the review of Goose Lake redband trout was limited by a lack of long-term data series. The first objective of this study was to document the current distribution of native fishes in Oregon’s portion of the Goose Lake basin and assess changes in distribution that may have occurred since the last surveys were conducted 12 years ago. The second objective was to provide new information about the distribution of Modoc suckers within the basin. The third objective was to determine relative abundance and age-class diversity of native fishes at randomly selected sample sites. All objectives were addressed throughout the potential riverine distribution of fish in the Oregon portion of the Goose Lake basin. Information gathered in this study is critical to effective conservation and management of each species and its habitat. In addition, this report describes the distribution and relative abundance of nonnative fishes (fathead minnow (Pimephales promelas), brown bullhead (Ameiurus nebulosus), white crappie (Pomoxis annularis), yellow perch (Perca flavescens), pumpkinseed (Lepomis gibbosus), and brook trout (Salvelinus fontinalis)) in the basin. Unlike prior efforts, this study used a statisticallybased design to select sample points with the aim of achieving a representative sample across the Oregon portion of the Goose Lake watershed. Additionally, a wide array of fish sampling gear was employed to maximize our ability to capture all fish species present across the diversity of habitat types encountered.
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442. [Article] Distribution of amphibians in wadeable streams and ponds in western and southeast Oregon, Information Report 2009-02
Abstract -- The Oregon Conservation Strategy (ODFW 2006) identified monitoring needs for 17 amphibian species native to the state of Oregon that are designated as “Strategy species”, or Species of Greatest ...Citation Citation
- Title:
- Distribution of amphibians in wadeable streams and ponds in western and southeast Oregon, Information Report 2009-02
Abstract -- The Oregon Conservation Strategy (ODFW 2006) identified monitoring needs for 17 amphibian species native to the state of Oregon that are designated as “Strategy species”, or Species of Greatest Conservation Need (per USFWS requirements for State Wildlife Action Plans). The distribution of many species of amphibians in western Oregon is sparsely documented (Oregon Conservation Strategy, page 27). Although a broad-scale survey for amphibian presence would provide much information about amphibian distribution, most studies have focused on limited areas. One cost-effective approach is to combine amphibian observational surveys with existing aquatic habitat surveys conducted as part of the Oregon Plan for Salmon and Watersheds (OCSRI 1997). The Oregon Plan has been in place since 1997 and the monitoring component provides a survey framework for streams in the lower Columbia River and Oregon coast drainages. The sampling framework is also compatible with implementation of the aquatic components of the Conservation Strategy, as demonstrated by this study. This study describes the presence of amphibians in and along wadeable streams in coastal and lower Columbia River drainages of Oregon, ponds and sloughs in the Willamette Valley, and selected streams in the Great Basin of southeast and central Oregon. As a component of monitoring under the Oregon Plan, the Aquatic Inventories Project (AIP) conducts aquatic habitat surveys at randomly selected and spatially balanced sites across all 1st through 4th order streams (wadeable) in coastal and lower Columbia River drainages. The purpose of the habitat surveys is to describe stream morphology, instream physical habitat, and riparian vegetation. Because the surveyors were already observing features within and alongside the stream channel, they were able to record observations of amphibians. The amphibian component was consistent with the survey protocol used by the US Geological Survey’s Amphibian Research and Monitoring Initiative. The advantage of coupling an amphibian component with the OR Plan aquatic surveys was that it not only was an efficient use of resources, but more importantly, provided information using a statistically rigorous survey design across a broad geographic area. In the summer of 2006, AIP began collecting amphibian occurrence data during physical stream habitat surveys as a pilot study to determine if our standard survey protocol could be modified to document distribution of amphibians characterized as Strategy Species under the Oregon Conservation Strategy. During the summer season, field crews observed four strategy species of amphibians and eleven amphibian species total. The potential to use these data to fill the gaps within the known current distribution of amphibians and to potentially develop a habitat based distribution models for these species led to the summer 2007 work. Amphibian data are also collected during four other survey projects, and although the site selection procedure does not conform to the same statistical standards as the Oregon Plan survey design, the projects offer a number of opportunities to collect amphibian occurrence information over a wide variety of habitats. The amphibian observations from these four projects are also included in this report. The four projects are as follows: • AIP conducts aquatic habitat surveys on selected streams throughout the state. • AIP conducts aquatic habitat surveys at stream habitat restoration projects in Western Oregon. • Surveys to document the distribution of Oregon chub also record amphibian data from over 1,000 pond and slough sites within the Willamette Valley floodplain since 1991. • The Native Fish Investigations Project began a study in 2007 to document the distribution and abundance of Redband Trout in the Great Basin region of Eastern Oregon. Surveys in the summer of 2007 occurred in 8 of Oregon’s 10 ecoregions (Figure 1)(Omernick 1994). Ecoregions are relatively large areas defined by distinctive geographic and ecological characteristics; flora and fauna communities and geographic conditions are typically distinct. Ecoregions provide an ecological framework for describing amphibian distribution across the state. The goals of our 2007 work were to: • Increase the consistency, efficiency and ability of habitat crews in identifying amphibians through improved training. • Increase knowledge of distribution and habitat associations of amphibians in streams in western Oregon (location, stream size and type), and infer distribution in all coastal and lower Columbia drainages. • Describe temporal changes in stream habitat use by amphibians (seasonal, annual). • Estimate surveyor bias by comparing standard crew data with intensive resurveys. • Describe distribution of amphibians in ponds, sloughs and other off channel aquatic habitats in the Willamette Valley. • Describe distribution of amphibians in the Great Basin of eastern Oregon. Many of Oregon’s amphibians rely on aquatic habitats at some point of their life, either for breeding and juvenile development or to inhabit as adults. Most aquatic amphibians breed from late winter to early summer, and many adults remain in or near their breeding sites into the summer. Most tadpoles and juvenile amphibians are also active in and occupy aquatic habitats during the summer. The aquatic habitat and redband trout surveys are appropriate opportunities to observe species and life stages (breeding adults, tadpoles and juveniles) that occupy aquatic or riparian habitats during the summer. Likewise the Oregon chub surveys are likely to observe amphibian species and life stages in ponds and sloughs during the spring and fall. These types of surveys are an efficient and cost-effective means to collect information on amphibian species that are closely tied to aquatic habitat throughout their life cycle. Amphibian species that are more terrestrial in nature may be better surveyed through a different approach.
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443. [Article] 2008 Amphibian Distribution Surveys in Wadeable Streams and Ponds in Western and Southeast Oregon, Information Reports Number 2010-05
Abstract -- The ODFW Oregon Conservation Strategy identified monitoring needs for 17 amphibian species native to the state of Oregon that are designated as “Strategy species”, or Species of Greatest Conservation ...Citation Citation
- Title:
- 2008 Amphibian Distribution Surveys in Wadeable Streams and Ponds in Western and Southeast Oregon, Information Reports Number 2010-05
Abstract -- The ODFW Oregon Conservation Strategy identified monitoring needs for 17 amphibian species native to the state of Oregon that are designated as “Strategy species”, or Species of Greatest Conservation Need (per USFWS requirements for State Wildlife Action Plans). The distribution of many species of amphibians in western Oregon is sparsely documented (Oregon Conservation Strategy, page 27). Although a broad-scale survey for amphibian presence would provide important baseline information about amphibian species composition and distribution, most studies have focused on limited areas. The majority of Oregon’s amphibians rely on aquatic habitats at some point of their life, either for breeding and juvenile development or to inhabit as adults. Most aquatic amphibians breed from late winter to early summer, and adults frequently remain in or near their breeding sites into the summer. Most tadpoles and juvenile amphibians are also active in and occupy aquatic habitats during the summer. Ongoing aquatic habitat and fish surveys are opportunities to observe species and life stages (breeding adults, tadpoles and juveniles) that occupy aquatic or riparian habitats during the summer. One cost-effective approach is to combine amphibian surveys with existing aquatic habitat and fish surveys such as those conducted as part of the Oregon Plan for Salmon and Watersheds (OCSRI 1997). The Oregon Plan has been in place since 1997 and the monitoring component provides a survey framework for streams in the lower Columbia River and Oregon coast drainages. The sampling framework is also compatible with implementation of the aquatic components of the Conservation Strategy, as demonstrated by this study. This study describes the presence of amphibians in and along wadeable streams in coast and lower Columbia River drainages of Oregon, ponds and sloughs in the Willamette Valley, and selected streams in the Great Basin of southeast and central Oregon. As a component of monitoring under the Oregon Plan, the Aquatic Inventories Project (AIP) conducts aquatic habitat surveys at randomly selected and spatially balanced sites across all 1st through 4th order streams in coastal and lower Columbia River drainages. The purpose of the habitat surveys is to describe stream morphology, instream physical habitat, and riparian vegetation. Because the surveyors were already observing features within and alongside the stream channel, they were able to record observations of amphibians. The amphibian component was consistent with the survey protocol used by the US Geological Survey’s Amphibian Research and Monitoring Initiative (http://armi.usgs.gov/). The advantage of coupling an amphibian component with the OR Plan aquatic surveys was that it not only was an efficient use of resources, but more importantly, provided information using a statistically rigorous survey design across a broad geographic area. The Native Fish Investigations Project began a six year study in 2007 to document the distribution and abundance of redband trout in the Great Basin region of Eastern Oregon. The site selection procedure is comparable to the statistical standards as the Oregon Plan survey design. Amphibian data are also collected during three other survey projects, and although the site selection procedure does not conform to the same statistical standards as the Oregon Plan survey design, the projects offer a number of opportunities to collect amphibian occurrence information over a wide variety of habitats. The amphibian observations from these three projects are also included in this report. The three projects are as follows: • AIP conducts aquatic habitat surveys on selected streams throughout the state. • AIP conducts aquatic habitat surveys at stream habitat restoration projects in Western Oregon. • Native Fish Project conducts surveys of pond and slough sites for Oregon chub in the Willamette Valley. Due to the success of the 2006 and 2007 field studies, we continued our research during the summer of 2008 to improve our knowledge of distribution and community structure of amphibians. The summer 2008 surveys took place in 9 of Oregon’s 10 ecoregions (Figure 1) (Thorson et al. 2003). Ecoregions provide a framework for discussing amphibian distribution across the state because they are relatively large areas defined by distinctive geographic and ecological (flora and fauna) characteristics. The goals of our 2008 work were to: • Increase the consistency, efficiency and ability of habitat crews in identifying amphibians through improved training. • Increase knowledge of distribution, community structure, and habitat associations of amphibians in streams in: o Western Oregon coastal and lower Columbia drainages. o Ponds, sloughs and other off-channel aquatic habitats in the Willamette Valley. o Great Basin of eastern Oregon and selected streams in central Oregon. • Combine the 2008 observations with the 2006-07 results.
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444. [Article] Abundance Monitoring of Juvenile Salmonids In Coastal Oregon and Lower Columbia Streams, 2008 Report Number: OPSW-ODFW-2009-1
Abstract -- As part of the Oregon Plan for Salmon and Watersheds, the Oregon Department of Fish and Wildlife (ODFW) initiated this project in 1998 to monitor the status and trend in abundance and distribution ...Citation Citation
- Title:
- Abundance Monitoring of Juvenile Salmonids In Coastal Oregon and Lower Columbia Streams, 2008 Report Number: OPSW-ODFW-2009-1
Abstract -- As part of the Oregon Plan for Salmon and Watersheds, the Oregon Department of Fish and Wildlife (ODFW) initiated this project in 1998 to monitor the status and trend in abundance and distribution of juvenile coho salmon (Oncorhynchus kisutch) in coastal Oregon streams. This report summarizes the data collected during the summer of 2008 and, for coho salmon, compares it to data previously collected. The project originally surveyed only 1st-3rd order (tributary) streams but was expanded in 2002 to include juvenile steelhead (Oncorhynchus mykiss) and 4th-6th order (mainstem) rearing areas and in 2006 to the Oregon portion of the Lower Columbia River coho evolutionarily significant unit (ESU) (Figure 1). The sampling frame is intended to encompass all non-tidal coho and steelhead rearing habitat. The original 100k stream layer frame was replaced by a 24k frame in 2007. A Generalized Random Tessellation Stratified design (GRTS) (Stevens 2002) was used to create a spatially balanced, random point distribution. Sites were stratified by Monitoring Area (MA) and stream order (Table 1). A detailed description of the sampling frames and survey designs are found in Jepsen and Rodgers (2004) and Jepsen and Leader (2007). Field crews snorkeled all pools meeting the size criteria (6 m2 in surface area and 40 cm in maximum depth) in one kilometer of stream encompassing the GRTS point. Snorkeling was conducted during the minimum flow period from July to September using a single pass of one to four snorkelers, depending on stream width. In each pool counts were made of juvenile coho, Chinook, steelhead 90 mm, and cutthroat 90 mm. Presence was noted for dace, shiners, and trout < 90 mm. Sites with poor water clarity or quality were electrofished using a single pass without block nets to determine presence for coho, steelhead and cutthroat in each pool. To assess repeatability and quality control supervisory staff resurveyed 10% of tributary sites in each MA. Data were summarized by MA and stream order for analyses. Average pool density and percent pool occupancy for each site was averaged by MA. The percent of sites with at least one fish and with >0.7 coho/m2 are reported for each MA. 0.7 coho/m2 is regarded as full seeding after Nickelson et al. (1992) who reported full seeding based on electrofishing as 1.0 coho/m2 and Rodgers et al. (1992) who found that snorkelers observed 70% of the coho counted by electrofishing. CDFs, variances, and confidence intervals were created using tools developed by the EMAP Design and Analysis Team (EPA 2009).
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445. [Article] Recovery of Wild Coho Salmon In Salmon River Basin, 2008-2010 Report Number: OPSW-ODFW-2011-10
Abstract -- Hatcheries have been a centerpiece of salmon management in the Pacific Northwest for more than a century but recent evidence of adverse interactions between hatchery and naturally-produced ...Citation Citation
- Title:
- Recovery of Wild Coho Salmon In Salmon River Basin, 2008-2010 Report Number: OPSW-ODFW-2011-10
Abstract -- Hatcheries have been a centerpiece of salmon management in the Pacific Northwest for more than a century but recent evidence of adverse interactions between hatchery and naturally-produced salmon have resulted in substantial changes in many hatchery programs. In 2007 the Oregon Department of Fish and Wildlife terminated a 30-year artificial propagation program for coho salmon in the Salmon River basin after a status assessment concluded that wild population viability was threatened by hatchery effects on salmon productivity (Chilcote et al. 2005). Hatchery-reared coho comprised 50-100% of the naturally spawning population in recent years. Low productivity was reflected in a low spawner to recruit ratio, and life-stage specific survival was lower than that of nearby populations. The temporal distribution of adult spawning in the basin was truncated and peaked 1.5 months earlier relative to the pre-hatchery period and adjacent coastal populations. The cessation of hatchery releases into Salmon River not only removed the primary factor believed to limit productivity of the local population, it also constituted a rare management experiment to test whether a naturally-spawning population can recover from a prolonged period of low abundance after interactions with hatchery-produced coho salmon are eliminated. This report summarizes the results of coho population studies at Salmon River for the first three years after the hatchery program was discontinued. The study in Salmon River is timely because ecological interactions between hatchery and wild fish have been implicated in the reduced survival and decreased productivity of wild coho and other salmonid populations (Nickelson 2003, Buhle et al. 2009, Chilcote et al. 2011). Recent studies involving a diversity of salmonid species and watersheds have shown a negative relationship between hatchery spawner abundance and wild population productivity regardless of the duration of hatchery influence (Chilcote et al. 2011). Yet neither the mechanisms of these productivity declines nor their potential reversibility have been investigated. Recent management changes at Salmon River provide an opportunity to experimentally evaluate coho salmon survival and productivity following the elimination of a decades-long hatchery program. The results will provide new insights into the reversibility of hatchery effects and the rate, mechanisms, and trajectory of response by a naturally spawning coho salmon population. Hatchery programs have been shown to change the timing and distribution of naturally spawning adults, but ecological and genetic influences on the spatial structure and life history diversity of juvenile populations are poorly understood. Conventional understanding of the life history of juvenile coho has presumed a relatively fixed pattern of rearing and migration. However, recent studies have found much greater variation in juvenile life history and habitat-use patterns than previously expected (Miller and Sadro 2003, Koski 2009), including evidence that estuaries may play a prominent role in the life histories of some coho salmon populations. A recent study in the Salmon River basin found considerable diversity in the life histories of juvenile Chinook salmon, including extended rearing by fry and other subyearling migrants within the complex network of natural and restored estuarine wetlands (Bottom et al. 2005). Unfortunately, interpretation of juvenile life history variations at Salmon River was confounded by the Chinook hatchery program, which has concentrated spawning activity in the lower river near the hatchery and may directly influence juvenile migration and rearing patterns. Discontinuation of the coho hatchery program at Salmon River provides an opportunity to quantify changes in juvenile life history following the elimination of all hatchery-fish interactions with the naturally spawning population. Such responses may provide important insights into the mechanisms of hatchery influence on wild salmon productivity and population resilience. Our research integrates adult and juvenile life stages, examines linkages to physical habitat conditions in fresh water and the estuary, and describes variability between juvenile performance and adult returns. It also monitors the coho salmon population across habitat types and life history stages to identify population responses at a landscape scale. We will determine productivity and survival at each salmon life stage and monitor the response of the adult population following the cessation of the coho salmon hatchery program. From these indicators, we will determine the potential resiliency of the coho salmon population, and evaluate the biological benefits or tradeoffs of returning the ecosystem to natural salmon production. Our study design encompasses four population phases: (1) pre-hatchery conditions (Mullen 1979), (2) dominance by hatchery-reared spawners (2008), (3) first generation naturally produced juveniles (2009-2011), and (4) second generation naturally produced juveniles (starting in 2012). This research will validate assumptions about factors limiting coho recovery and determine whether recovery actions have been effective. Here, we report on findings from 2008-2010 to address four principal objectives: 1. Quantify life stage specific survival and recruits per spawner ratio of the coho salmon population before and after hatchery coho salmon are removed from Salmon River. 2. Assess whether the Salmon River coho population is limited by capacity 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 various juvenile life histories to adult returns. 4. Determine seasonal use of the Salmon River estuary and its tidally-inundated wetlands by juvenile coho salmon. The field sampling that supported the study on coho salmon also captured Chinook salmon and steelhead and cutthroat trout during routine sampling in the watershed and estuary. This report emphasizes coho salmon results, but also summarizes catch, distribution, and migration data for other salmonids to compare densities and abundances in freshwater and the estuary. Additional results for Chinook, steelhead, and cutthroat are presented in Appendix A. See Stein et al. (2011) for more detailed information on life history diversity, migration patterns, habitat use, and abundance of cutthroat trout.
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446. [Article] Amphibian Distribution in Wadeable Streams and Ponds in Western and Southeast Oregon, 2009-2010 Progress Reports 2011
Abstract -- The ODFW Oregon Conservation Strategy identified monitoring needs for 17 amphibian species native to the state of Oregon that are designated as “Strategy Species”, or “Species of Greatest Conservation ...Citation Citation
- Title:
- Amphibian Distribution in Wadeable Streams and Ponds in Western and Southeast Oregon, 2009-2010 Progress Reports 2011
Abstract -- The ODFW Oregon Conservation Strategy identified monitoring needs for 17 amphibian species native to the state of Oregon that are designated as “Strategy Species”, or “Species of Greatest Conservation Need” (per USFWS requirements for State Wildlife Action Plans). The distribution of many species of amphibians in western Oregon is sparsely documented (Oregon Conservation Strategy, page 27). Although a broad-scale survey for amphibian presence would provide important baseline information about amphibian species composition and distribution, most studies have focused on limited areas. The majority of Oregon’s amphibians rely on aquatic habitats at some point of their life, either for breeding and juvenile development or to inhabit as adults. Most aquatic amphibians breed from late winter to early summer, and adults frequently remain in or near their breeding sites into the summer. Most tadpoles and juvenile amphibians are also active in and occupy aquatic habitats during the summer. Ongoing aquatic habitat and fish surveys are opportunities to observe species and life stages (breeding adults, tadpoles and juveniles) that occupy aquatic or riparian habitats during the summer. One cost-effective approach is to combine amphibian surveys with existing aquatic habitat and fish surveys such as those conducted as part of the Oregon Plan for Salmon and Watersheds (OCSRI 1997). The Oregon Plan has been in place since 1997 and the monitoring component provides a survey framework for streams in the lower Columbia River and Oregon coast drainages. The sampling framework is also compatible with implementation of the aquatic components of the Conservation Strategy, as demonstrated by this study. This study describes the presence of amphibians in and along wadeable streams in coast and lower Columbia River drainages of Oregon, ponds and sloughs in the Willamette Valley, and selected streams in the Great Basin of southeast and central Oregon. As a component of monitoring under the Oregon Plan, the Aquatic Inventories Project (AIP) conducts aquatic habitat surveys at randomly selected and spatially balanced sites across all 1st through 4th order streams in coastal and lower Columbia River drainages. The purpose of the habitat surveys is to describe stream morphology, instream physical habitat, and riparian vegetation. Because the surveyors were already observing features within and alongside the stream channel, they were able to record observations of amphibians. The advantage of coupling an amphibian component with the OR Plan aquatic surveys was that it not only was an efficient use of resources, but more importantly, provided information using a statistically rigorous survey design across a broad geographic area. The Native Fish Investigations Project began a six year study in 2007 to document the distribution and abundance of redband trout in the Great Basin region of Eastern Oregon. The site selection procedure is comparable to the statistical standards as the Oregon Plan survey design. Amphibian data are also collected during three other survey projects, and although the site selection procedure does not conform to the same statistical standards as the Oregon Plan survey design, the projects offer a number of opportunities to collect amphibian occurrence information over a wide variety of habitats. The amphibian observations from these three projects are also included in this report. The three projects are as follows: AIP conducts aquatic habitat surveys on selected streams throughout the state. AIP conducts aquatic habitat surveys at stream habitat restoration projects in Western Oregon. Native Fish Project conducts surveys of pond and slough sites for Oregon chub in the Willamette Valley. Due to the success of the 2007 and 2008 field studies, we continued our research during the summer of 2009 and 2010 to improve our knowledge of distribution and community structure of amphibians. The summer 2009 and 2010 surveys took place in 9 of Oregon’s 10 ecoregions (Figure 1) (Thorson et al. 2003). Ecoregions provide a framework for discussing amphibian distribution across the state because they are relatively large areas defined by distinctive geographic and ecological (flora and fauna) characteristics. The goals of our 2009-2010 work were to: Increase the consistency, efficiency and ability of habitat crews in identifying amphibians through improved training. Increase knowledge of distribution, community structure, and habitat associations of amphibians in streams in: Western Oregon coastal and lower Columbia drainages. Ponds, sloughs and other off-channel aquatic habitats in the Willamette Valley. Great Basin of eastern Oregon and selected streams in central Oregon. Combine the 2009-2010 observations with the 2007-2008 results.
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447. [Article] Information Report 2018-01; Winter Habitat Condition of Oregon Coast Coho Salmon Populations, 2007-2014
Abstract -- In this report we summarize results of eight years (2007-2014) of habitat surveys for 18 independent Oregon coast coho salmon populations across four monitoring strata (North Coast, Mid Coast, ...Citation Citation
- Title:
- Information Report 2018-01; Winter Habitat Condition of Oregon Coast Coho Salmon Populations, 2007-2014
Abstract -- In this report we summarize results of eight years (2007-2014) of habitat surveys for 18 independent Oregon coast coho salmon populations across four monitoring strata (North Coast, Mid Coast, MidSouth Coast, and Umpqua) in the Oregon Coast Coho Salmon Evolutionary Significant Unit (ESU). We also sampled dependent population blocks across three monitoring strata (North Coast, Mid Coast, and Mid-South Coast). Using a spatially balanced site selection process (Generalized Random Tessellation Stratification; GRTS) we surveyed 451 unique sites within the range of coho salmon spawning or rearing. With the exception of the 2014 survey year, habitat data were collected during winter conditions (February – March). Habitat sampled in 2014 occurred within the summer field season (June – September). We used a Habitat Limiting Factors Model (HLFM) to estimate habitat capacity for winter coho parr and the HabRate model to assess habitat quality for each surveyed stream reach. HLFM estimates were expanded based on the total coho distribution in each population. Based on the habitat data the HLFM predicted the Floras population could support the highest density of juvenile coho (1568 parr/km), while the streams in the Siltcoos watershed could support the least (290 parr/km). At the ESU-level, there was no detectable change of high quality rearing habitat (= 1850 parr/km) when compared to previous studies, but changes were observed among populations over the course of these survey years. We compared individual habitat metrics across populations, land use, geology, and between independent and dependent populations. While no significant differences were observed between independent and dependent populations, differences in habitat metrics were detected among individual populations, land use types, and geologies. In addition, we detected a difference in reproductive habitat quality (spawning and emergence) between both populations and land use types.