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• 1. [Article] Oregon South Coast Estuaries: Hunter Creek, Pistol River, Chetco River, & Winchuck River Tidal Wetlands Assessment (2012-2015)

  Abstract -- Although tidal wetlands on the Oregon South Coast are limited in extent, they may be particularly valuable for a variety of wetland functions. This assessment combines the Brophy (2007) and ...

  Citation × Citation Citation Abstract Copy Title: Oregon South Coast Estuaries: Hunter Creek, Pistol River, Chetco River, & Winchuck River Tidal Wetlands Assessment (2012-2015) Abstract -- Although tidal wetlands on the Oregon South Coast are limited in extent, they may be particularly valuable for a variety of wetland functions. This assessment combines the Brophy (2007) and Adamus (2005) approaches to quantify the extent and causes of habitat loss and hydrogeomorphic changes in tidal wetlands of four Oregon South Coast Estuaries. The potential for restoring critical habitat and wetland functions is ranked using Ecological Prioritization Criteria (Brophy, 2007), while indicators of function, risk, and integrity are evaluated using scoring models from the Adamus (2005) Hydrogeomorphic (HGM) Rapid Assessment Method. The extent of inundation (head of tide) during King Tide conditions was observed and documented by staff and volunteers. Field measurements of salinity concentrations and stratification during high and low flow were tabulated. The historic aerial photo record was examined to detect channel migration, floodplain re-vegetation, and human-caused alterations. Related studies were combined with these observations to provide a summary of estuary hydrology, sedimentation, and channel stability related to wetland establishment and loss in each of the four estuaries. Ecological priority scores (Brophy, 2007) varied with wetland size, tidal channel condition, connectivity, and diversity of vegetation classes. Wetlands were categorized as restoration or conservation types, and priority ranks for wetlands were depicted on orthophoto base maps. Tidal wetlands and nearby floodplain wetlands in a variety of geomorphic settings were surveyed using the HGM protocol, including one “reference” and one restoration site . The HGM survey scores 55 indicators, including botanical transects, used to rank wetland functions (calculated by indicator scoring models). Risks to wetlands include human disturbances in close proximity to the wetlands and floodplains, resulting from the narrow valley floors in this tectonically active region. Wetland integrity is threatened by a surprising large proportion of non-native species in the botanical transects, 40%. Wetland indicators that scored low, and could be restored or enhanced, are discussed in a restoration considerations narrative. Wetland descriptions include lists of plant species, grouped by wetland status, native/non-native, and perennial/annual persistence. In addition to the HGM scores, an analysis of cover and diversity of all plant species in plots, off-transect species diversity, and waterfowl food distribution was completed using a wetland vegetation database developed for the Oregon South Coast. Title: Oregon South Coast Estuaries: Hunter Creek, Pistol River, Chetco River, & Winchuck River Tidal Wetlands Assessment (2012-2015) Abstract -- Although tidal wetlands on the Oregon South Coast are limited in extent, they may be particularly valuable for a variety of wetland functions. This assessment combines the Brophy (2007) and Adamus (2005) approaches to quantify the extent and causes of habitat loss and hydrogeomorphic changes in tidal wetlands of four Oregon South Coast Estuaries. The potential for restoring critical habitat and wetland functions is ranked using Ecological Prioritization Criteria (Brophy, 2007), while indicators of function, risk, and integrity are evaluated using scoring models from the Adamus (2005) Hydrogeomorphic (HGM) Rapid Assessment Method. The extent of inundation (head of tide) during King Tide conditions was observed and documented by staff and volunteers. Field measurements of salinity concentrations and stratification during high and low flow were tabulated. The historic aerial photo record was examined to detect channel migration, floodplain re-vegetation, and human-caused alterations. Related studies were combined with these observations to provide a summary of estuary hydrology, sedimentation, and channel stability related to wetland establishment and loss in each of the four estuaries. Ecological priority scores (Brophy, 2007) varied with wetland size, tidal channel condition, connectivity, and diversity of vegetation classes. Wetlands were categorized as restoration or conservation types, and priority ranks for wetlands were depicted on orthophoto base maps. Tidal wetlands and nearby floodplain wetlands in a variety of geomorphic settings were surveyed using the HGM protocol, including one “reference” and one restoration site . The HGM survey scores 55 indicators, including botanical transects, used to rank wetland functions (calculated by indicator scoring models). Risks to wetlands include human disturbances in close proximity to the wetlands and floodplains, resulting from the narrow valley floors in this tectonically active region. Wetland integrity is threatened by a surprising large proportion of non-native species in the botanical transects, 40%. Wetland indicators that scored low, and could be restored or enhanced, are discussed in a restoration considerations narrative. Wetland descriptions include lists of plant species, grouped by wetland status, native/non-native, and perennial/annual persistence. In addition to the HGM scores, an analysis of cover and diversity of all plant species in plots, off-transect species diversity, and waterfowl food distribution was completed using a wetland vegetation database developed for the Oregon South Coast. Close

• 2. [Article] NF - Effect of Bull Trout and Brook Trout Interactions on Foraging Habitat, Feeding Behavior, and Growth

  Abstract -- Observations of free-ranging sympatric bull trout Salvelinus confluentus and nonnative brook trout S. fontinalis in two eastern Oregon headwater streams provided little evidence of habitat ...

  Citation × Citation Citation Abstract Copy Title: NF - Effect of Bull Trout and Brook Trout Interactions on Foraging Habitat, Feeding Behavior, and Growth Abstract -- Observations of free-ranging sympatric bull trout Salvelinus confluentus and nonnative brook trout S. fontinalis in two eastern Oregon headwater streams provided little evidence of habitat partitioning. Both species held focal feeding points in similar microhabitats and fed primarily from the water column rather than from the surface or benthos. In an instream experiment, 20 enclosures were assigned one of three treatments: two bull trout, four bull trout, or a mix of two bull trout and two brook trout. In the enclosures, macroinvertebrate drift was restricted and trout densities were elevated, creating an environment of reduced food and habitat resources. Under these conditions, there was no indication of a niche shift by bull trout; feeding behavior and habitat use by bull trout did not differ depending on the presence or absence of brook trout. Brook trout in the mixed-species treatment were the most aggressive, maintained dominance in 75% of the enclosures, and exhibited significantly higher growth than sympatric bull trout. However, the effects of intra-and interspecific interactions on bull trout growth were equivalent. Given the absence of resource partitioning and a niche shift by bull trout in the presence of brook trout (despite obvious interference interactions), we suggest that the displacement of bull trout by brook trout is likely when resources are scarce. Title: NF - Effect of Bull Trout and Brook Trout Interactions on Foraging Habitat, Feeding Behavior, and Growth Abstract -- Observations of free-ranging sympatric bull trout Salvelinus confluentus and nonnative brook trout S. fontinalis in two eastern Oregon headwater streams provided little evidence of habitat partitioning. Both species held focal feeding points in similar microhabitats and fed primarily from the water column rather than from the surface or benthos. In an instream experiment, 20 enclosures were assigned one of three treatments: two bull trout, four bull trout, or a mix of two bull trout and two brook trout. In the enclosures, macroinvertebrate drift was restricted and trout densities were elevated, creating an environment of reduced food and habitat resources. Under these conditions, there was no indication of a niche shift by bull trout; feeding behavior and habitat use by bull trout did not differ depending on the presence or absence of brook trout. Brook trout in the mixed-species treatment were the most aggressive, maintained dominance in 75% of the enclosures, and exhibited significantly higher growth than sympatric bull trout. However, the effects of intra-and interspecific interactions on bull trout growth were equivalent. Given the absence of resource partitioning and a niche shift by bull trout in the presence of brook trout (despite obvious interference interactions), we suggest that the displacement of bull trout by brook trout is likely when resources are scarce. Close

• 3. [Article] 2009 Borax Lake Chub Investigations Progress Reports 2009

  Abstract -- The Borax Lake chub (Gila boraxobius) is a small minnow endemic to Borax Lake and adjacent wetlands in the Alvord Basin in Harney County, Oregon (Williams and Bond 1980). Borax Lake chub are ...

  Citation × Citation Citation Abstract Copy Title: 2009 Borax Lake Chub Investigations Progress Reports 2009 Abstract -- The Borax Lake chub (Gila boraxobius) is a small minnow endemic to Borax Lake and adjacent wetlands in the Alvord Basin in Harney County, Oregon (Williams and Bond 1980). Borax Lake chub are represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake. Borax Lake is a natural lake perched 10 meters above the desert floor on sinter deposits, which is fed almost exclusively by thermal groundwater. The Borax Lake chub was listed as endangered under the federal Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982). Population abundance estimates obtained since 1991 indicate a fluctuating population ranging between approximately 4,000 and 34,000 fish (Salzer 1997; Scheerer and Jacobs 2008). The basis for the Borax Lake chub’s listed status was not population size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust shoreline could reduce lake levels and the habitat quantity and quality available to Borax Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration caused by geothermal energy development and alteration of the lake shore crust to provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery plan, completed in 1987, advocated protection of the lake ecosystem through the acquisition of key private lands, protection of groundwater and surface waters, controls on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987). Recovery measures implemented since listing have improved the conservation status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003). When the species was listed, critical habitat was designated on 259 hectares of land surrounding the lake, including 129 hectares of public lands and two 65-hectare parcels of private land. In 1983, the U.S. Bureau of Land Management designated the public land as an Area of Critical Environmental Concern. The Nature Conservancy began leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical habitat into public or conservation ownership. The Nature Conservancy ended water diversion from the lake for irrigation and livestock grazing within the critical habitat. Passage of the Steens Mountain Cooperative Management and Protection Act of 2000 removed the public BLM lands from mineral and geothermal development within a majority of the basin. These actions, combined with detailed studies of the chub and their habitat, have added substantially to our knowledge of the Borax Lake ecosystem (Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils from a recent increase in recreational use around the lake (particularly off-road vehicle usage), the threat of introduction of nonnative species, and potential negative impacts to the aquifer from geothermal groundwater withdrawal if groundwater pumping were to occur on private lands outside the protected areas (Williams and Macdonald 2003). A review of the conservation status of the Borax Lake chub by Williams and Macdonald (2003) cited the lack of recent and ongoing population and ecosystem monitoring as one argument against downlisting or delisting the species at that time. Although an increase in abundance is not a goal in the successful recovery of this species, monitoring trends in abundance over time is an important management tool to assess species status. The objectives of this study were to: 1) obtain a mark-recapture population estimate of Borax Lake chub and 2) to evaluate habitat conditions at Borax Lake, including the condition of the fragile lake shoreline and outflows. This report describes results from monitoring conducted by Oregon Department of Fish and Wildlife’s Native Fish Investigations Project in 2009. Title: 2009 Borax Lake Chub Investigations Progress Reports 2009 Abstract -- The Borax Lake chub (Gila boraxobius) is a small minnow endemic to Borax Lake and adjacent wetlands in the Alvord Basin in Harney County, Oregon (Williams and Bond 1980). Borax Lake chub are represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake. Borax Lake is a natural lake perched 10 meters above the desert floor on sinter deposits, which is fed almost exclusively by thermal groundwater. The Borax Lake chub was listed as endangered under the federal Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982). Population abundance estimates obtained since 1991 indicate a fluctuating population ranging between approximately 4,000 and 34,000 fish (Salzer 1997; Scheerer and Jacobs 2008). The basis for the Borax Lake chub’s listed status was not population size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust shoreline could reduce lake levels and the habitat quantity and quality available to Borax Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration caused by geothermal energy development and alteration of the lake shore crust to provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery plan, completed in 1987, advocated protection of the lake ecosystem through the acquisition of key private lands, protection of groundwater and surface waters, controls on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987). Recovery measures implemented since listing have improved the conservation status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003). When the species was listed, critical habitat was designated on 259 hectares of land surrounding the lake, including 129 hectares of public lands and two 65-hectare parcels of private land. In 1983, the U.S. Bureau of Land Management designated the public land as an Area of Critical Environmental Concern. The Nature Conservancy began leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical habitat into public or conservation ownership. The Nature Conservancy ended water diversion from the lake for irrigation and livestock grazing within the critical habitat. Passage of the Steens Mountain Cooperative Management and Protection Act of 2000 removed the public BLM lands from mineral and geothermal development within a majority of the basin. These actions, combined with detailed studies of the chub and their habitat, have added substantially to our knowledge of the Borax Lake ecosystem (Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils from a recent increase in recreational use around the lake (particularly off-road vehicle usage), the threat of introduction of nonnative species, and potential negative impacts to the aquifer from geothermal groundwater withdrawal if groundwater pumping were to occur on private lands outside the protected areas (Williams and Macdonald 2003). A review of the conservation status of the Borax Lake chub by Williams and Macdonald (2003) cited the lack of recent and ongoing population and ecosystem monitoring as one argument against downlisting or delisting the species at that time. Although an increase in abundance is not a goal in the successful recovery of this species, monitoring trends in abundance over time is an important management tool to assess species status. The objectives of this study were to: 1) obtain a mark-recapture population estimate of Borax Lake chub and 2) to evaluate habitat conditions at Borax Lake, including the condition of the fragile lake shoreline and outflows. This report describes results from monitoring conducted by Oregon Department of Fish and Wildlife’s Native Fish Investigations Project in 2009. Close

• 4. [Article] 2007 Oregon Chub Investigations Progress Reports 2007

  Abstract -- Oregon chub Oregonichthys crameri, small minnows endemic to the Willamette Valley, were federally listed as endangered under the Endangered Species Act in 1993. Factors implicated in the decline ...

  Citation × Citation Citation Abstract Copy Title: 2007 Oregon Chub Investigations Progress Reports 2007 Abstract -- Oregon chub Oregonichthys crameri, small minnows endemic to the Willamette Valley, were federally listed as endangered under the Endangered Species Act in 1993. Factors implicated in the decline of this species include changes in flow regimes and habitat characteristics resulting from the construction of flood control dams, revetments, channelization, diking, and the drainage of wetlands. The Oregon chub is further threatened by predation and competition by non-native species such as largemouth bass Micropterus salmoides, crappies Pomoxis sp., sunfishes Lepomis sp., bullheads Ameiurus sp., and western mosquitofish Gambusia affinis. We continued surveys initiated in 1991 in the Willamette River drainage to quantify the abundance of known Oregon chub populations, search for unknown populations, evaluate potential introduction sites, and monitor introduced populations as part of the implementation of the Oregon Chub Recovery Plan. We sampled a total of 70 sites in 2007. New populations of Oregon chub were discovered at Green Island in the lower McKenzie River and in the Muddy Creek drainage (Linn County). We confirmed the continued existence of Oregon chub at 34 locations. These included 23 naturally occurring and 11 introduced populations. We did not find Oregon chub at nine locations where they were collected on at least one occasion between 1991-2006. Nonnative fish were collected at most of these locations. We obtained abundance estimates of 18 naturally occurring populations and 11 introduced populations of Oregon chub located in the Middle Fork Willamette, Santiam, McKenzie, and Mid-Willamette drainages (Table 1). We introduced additional Oregon chub into the South Stayton Pond in the Santiam drainage and into Cheadle and Display Ponds in the Mid-Willamette drainage. The Oregon Chub Recovery Plan (U.S. Fish and Wildlife Service 1998) set recovery criteria for downlisting the species to “threatened” and for delisting the species. The criteria for downlisting the species are: 1) establish and manage 10 populations of at least 500 adult fish, 2) all of these populations must exhibit a stable or increasing trend for five years, and 3) at least three populations meeting criterion 1 and 2 must be located in each of the three recovery areas (Middle Fork Willamette River, Santiam River, and Mid-Willamette River tributaries). In 2007, there were 20 populations totaling 500 or more individuals (Table 1). Fifteen of these populations also met the second criteria. Of the 15 populations meeting criteria 1 and 2, eight were located in the Middle Fork Willamette drainage, four were located in the Mid-Willamette drainage, and three were located in the Santiam drainage. In 2007, we met the downlisting criteria. Findings to date indicate that Oregon chub remain at risk due to the loss of suitable habitat and the continued threats posed by the proliferation of non-native fishes, illegal water withdrawals, accelerated sedimentation, and potential chemical spills or careless pesticide applications. Their status has improved in recent years, resulting primarily from successful introductions and the discovery of previously undocumented populations. Title: 2007 Oregon Chub Investigations Progress Reports 2007 Abstract -- Oregon chub Oregonichthys crameri, small minnows endemic to the Willamette Valley, were federally listed as endangered under the Endangered Species Act in 1993. Factors implicated in the decline of this species include changes in flow regimes and habitat characteristics resulting from the construction of flood control dams, revetments, channelization, diking, and the drainage of wetlands. The Oregon chub is further threatened by predation and competition by non-native species such as largemouth bass Micropterus salmoides, crappies Pomoxis sp., sunfishes Lepomis sp., bullheads Ameiurus sp., and western mosquitofish Gambusia affinis. We continued surveys initiated in 1991 in the Willamette River drainage to quantify the abundance of known Oregon chub populations, search for unknown populations, evaluate potential introduction sites, and monitor introduced populations as part of the implementation of the Oregon Chub Recovery Plan. We sampled a total of 70 sites in 2007. New populations of Oregon chub were discovered at Green Island in the lower McKenzie River and in the Muddy Creek drainage (Linn County). We confirmed the continued existence of Oregon chub at 34 locations. These included 23 naturally occurring and 11 introduced populations. We did not find Oregon chub at nine locations where they were collected on at least one occasion between 1991-2006. Nonnative fish were collected at most of these locations. We obtained abundance estimates of 18 naturally occurring populations and 11 introduced populations of Oregon chub located in the Middle Fork Willamette, Santiam, McKenzie, and Mid-Willamette drainages (Table 1). We introduced additional Oregon chub into the South Stayton Pond in the Santiam drainage and into Cheadle and Display Ponds in the Mid-Willamette drainage. The Oregon Chub Recovery Plan (U.S. Fish and Wildlife Service 1998) set recovery criteria for downlisting the species to “threatened” and for delisting the species. The criteria for downlisting the species are: 1) establish and manage 10 populations of at least 500 adult fish, 2) all of these populations must exhibit a stable or increasing trend for five years, and 3) at least three populations meeting criterion 1 and 2 must be located in each of the three recovery areas (Middle Fork Willamette River, Santiam River, and Mid-Willamette River tributaries). In 2007, there were 20 populations totaling 500 or more individuals (Table 1). Fifteen of these populations also met the second criteria. Of the 15 populations meeting criteria 1 and 2, eight were located in the Middle Fork Willamette drainage, four were located in the Mid-Willamette drainage, and three were located in the Santiam drainage. In 2007, we met the downlisting criteria. Findings to date indicate that Oregon chub remain at risk due to the loss of suitable habitat and the continued threats posed by the proliferation of non-native fishes, illegal water withdrawals, accelerated sedimentation, and potential chemical spills or careless pesticide applications. Their status has improved in recent years, resulting primarily from successful introductions and the discovery of previously undocumented populations. Close

• 5. [Article] 2006 Borax Lake Chub Investigations Progress Reports 2006

  Abstract -- Borax Lake chub (Gila boraxobius) is represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake in Harney County, Oregon. The Borax Lake chub is a small ...

  Citation × Citation Citation Abstract Copy Title: 2006 Borax Lake Chub Investigations Progress Reports 2006 Abstract -- Borax Lake chub (Gila boraxobius) is represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake in Harney County, Oregon. The Borax Lake chub is a small minnow endemic to Borax Lake and adjacent wetlands in Oregon’s Alvord Basin (Williams and Bond 1980). Borax Lake is a natural lake, perched 10 meters above the desert floor on sinter deposits, which is fed almost exclusively by thermal groundwater. The Borax Lake chub was listed as endangered under the federal Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982). Population abundance estimates obtained in 1991-1996 indicated a fluctuating population ranging from a low of 8,144 fish to a high of 34,634 fish (Salzer 1997). The basis for the Borax Lake chub’s listed status was not population size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust shoreline could reduce lake levels and the habitat quantity and quality available to Borax Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration caused by geothermal energy development and alteration of the lake shore crust to provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery plan, completed in 1987, advocated protection of the lake ecosystem through the acquisition of key private lands, protection of groundwater and surface waters, controls on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987). Numerous recovery measures implemented since listing have improved the conservation status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003). When the species was listed, critical habitat was designated on 259 hectares of land surrounding the lake, including 129 hectares of public lands and two 65- hectare parcels of private land. In 1983, the U.S. Bureau of Land Management designated the public land as an Area of Critical Environmental Concern. The Nature Conservancy began leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical habitat into public or conservation ownership. The Nature Conservancy ended water diversion from the lake for irrigation and livestock grazing within the critical habitat. Passage of the Steens Mountain Cooperative Management and Protection Act of 2000 removed the public BLM lands from mineral and geothermal development within a majority of the basin. These actions, combined with detailed studies of the chub and their habitat have added substantially to our knowledge of the Borax Lake ecosystem (Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils from a recent increase in recreational use around the lake (particularly off-road vehicle usage), the threat of introduction of nonnative species, and potential negative impacts to the aquifer from geothermal groundwater withdrawal if groundwater pumping were to occur on private lands outside the protected areas (Williams and Macdonald 2003). Although an increase in abundance is not a goal in the successful recovery of this species, monitoring trends in abundance over time is an important management tool to assess species status. From 1998-2004, data describing the abundance of the Borax Lake chub population are not available. Abundance estimates were obtained from 1986- 1997 by The Nature Conservancy (Salzer 1997) (Figure 1). Abundance estimates for 1986-1990 are not comparable with those obtained in 1991-1997. Prior to 1991, estimates were obtained only from traps set around the perimeter of the lake. In 1991, estimates were obtained from traps set on a regularly spaced grid throughout the lake. A study comparing the methods suggests that prior to 1991 abundance was under estimated, perhaps by as much as 50 percent (Salzer 1992). A recent review of the conservation status of the Borax Lake chub by Williams and Macdonald (2003) cited the lack of recent and ongoing population and ecosystem monitoring as one argument against downlisting or delisting the species at this time. The chub population has experienced substantial fluctuations in abundance over the time period (1986-1997) when abundance data are available (Figure 1). At the time of the review, the most recent abundance estimates that were obtained in 1996 and 1997 were some of the lowest estimates since 1991. Borax Lake chub population abundance estimates from 1986 to 1997 and 2005 to 2006. Horizontal bars represent 95% confidence limits. In 1986-1990 (solid symbols), only the perimeter of the lake was trapped. After 1990 (open symbols) the entire lake was trapped. Estimates are not directly comparable across these time periods. There are limited data on population age structure that offer valuable insight into the productivity of Borax Lake chub. Williams and Bond (1983) examined lengthfrequency data and concluded that the population consisted primarily of age 1 fish, with few age 2 and age 3 fish present. Limited opercle bone aging of chub collected in 1992- 1993 also indicated that most Borax Lake were less than one year of age (67-79%), yet a few individuals were aged at 10+ years (Scoppettone 1995). Because Borax Lake chub are only found in one location and the population is apparently dominated by a single year-class of adults, the species has a high inherent risk of extinction. 3 The objectives of this study were to: 1) obtain a mark-recapture population estimate of Borax Lake chub, and 2) to evaluate ways to reduce handling of Borax Lake chub when monitoring population abundance both by modifying previous mark-recapture protocols and by developing snorkeling survey protocols to use as an alternative to mark-recapture estimates. In addition, we collected data regarding lake temperatures, chub size (age) structure, and the condition of the fragile lake shoreline and outflows. Title: 2006 Borax Lake Chub Investigations Progress Reports 2006 Abstract -- Borax Lake chub (Gila boraxobius) is represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake in Harney County, Oregon. The Borax Lake chub is a small minnow endemic to Borax Lake and adjacent wetlands in Oregon’s Alvord Basin (Williams and Bond 1980). Borax Lake is a natural lake, perched 10 meters above the desert floor on sinter deposits, which is fed almost exclusively by thermal groundwater. The Borax Lake chub was listed as endangered under the federal Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982). Population abundance estimates obtained in 1991-1996 indicated a fluctuating population ranging from a low of 8,144 fish to a high of 34,634 fish (Salzer 1997). The basis for the Borax Lake chub’s listed status was not population size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust shoreline could reduce lake levels and the habitat quantity and quality available to Borax Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration caused by geothermal energy development and alteration of the lake shore crust to provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery plan, completed in 1987, advocated protection of the lake ecosystem through the acquisition of key private lands, protection of groundwater and surface waters, controls on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987). Numerous recovery measures implemented since listing have improved the conservation status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003). When the species was listed, critical habitat was designated on 259 hectares of land surrounding the lake, including 129 hectares of public lands and two 65- hectare parcels of private land. In 1983, the U.S. Bureau of Land Management designated the public land as an Area of Critical Environmental Concern. The Nature Conservancy began leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical habitat into public or conservation ownership. The Nature Conservancy ended water diversion from the lake for irrigation and livestock grazing within the critical habitat. Passage of the Steens Mountain Cooperative Management and Protection Act of 2000 removed the public BLM lands from mineral and geothermal development within a majority of the basin. These actions, combined with detailed studies of the chub and their habitat have added substantially to our knowledge of the Borax Lake ecosystem (Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils from a recent increase in recreational use around the lake (particularly off-road vehicle usage), the threat of introduction of nonnative species, and potential negative impacts to the aquifer from geothermal groundwater withdrawal if groundwater pumping were to occur on private lands outside the protected areas (Williams and Macdonald 2003). Although an increase in abundance is not a goal in the successful recovery of this species, monitoring trends in abundance over time is an important management tool to assess species status. From 1998-2004, data describing the abundance of the Borax Lake chub population are not available. Abundance estimates were obtained from 1986- 1997 by The Nature Conservancy (Salzer 1997) (Figure 1). Abundance estimates for 1986-1990 are not comparable with those obtained in 1991-1997. Prior to 1991, estimates were obtained only from traps set around the perimeter of the lake. In 1991, estimates were obtained from traps set on a regularly spaced grid throughout the lake. A study comparing the methods suggests that prior to 1991 abundance was under estimated, perhaps by as much as 50 percent (Salzer 1992). A recent review of the conservation status of the Borax Lake chub by Williams and Macdonald (2003) cited the lack of recent and ongoing population and ecosystem monitoring as one argument against downlisting or delisting the species at this time. The chub population has experienced substantial fluctuations in abundance over the time period (1986-1997) when abundance data are available (Figure 1). At the time of the review, the most recent abundance estimates that were obtained in 1996 and 1997 were some of the lowest estimates since 1991. Borax Lake chub population abundance estimates from 1986 to 1997 and 2005 to 2006. Horizontal bars represent 95% confidence limits. In 1986-1990 (solid symbols), only the perimeter of the lake was trapped. After 1990 (open symbols) the entire lake was trapped. Estimates are not directly comparable across these time periods. There are limited data on population age structure that offer valuable insight into the productivity of Borax Lake chub. Williams and Bond (1983) examined lengthfrequency data and concluded that the population consisted primarily of age 1 fish, with few age 2 and age 3 fish present. Limited opercle bone aging of chub collected in 1992- 1993 also indicated that most Borax Lake were less than one year of age (67-79%), yet a few individuals were aged at 10+ years (Scoppettone 1995). Because Borax Lake chub are only found in one location and the population is apparently dominated by a single year-class of adults, the species has a high inherent risk of extinction. 3 The objectives of this study were to: 1) obtain a mark-recapture population estimate of Borax Lake chub, and 2) to evaluate ways to reduce handling of Borax Lake chub when monitoring population abundance both by modifying previous mark-recapture protocols and by developing snorkeling survey protocols to use as an alternative to mark-recapture estimates. In addition, we collected data regarding lake temperatures, chub size (age) structure, and the condition of the fragile lake shoreline and outflows. Close

• 6. [Article] AI - Stream Habitat Conditions on Industrial Forest Lands in Coastal Oregon

  Abstract -- In the summer of 1998 and 1999, watersheds in western Oregon were randomly sampled for stream habitat conditions. Sites were selected using a random tessellation stratified design. Oregon Department ...

  Citation × Citation Citation Abstract Copy Title: AI - Stream Habitat Conditions on Industrial Forest Lands in Coastal Oregon Abstract -- In the summer of 1998 and 1999, watersheds in western Oregon were randomly sampled for stream habitat conditions. Sites were selected using a random tessellation stratified design. Oregon Department of Fish and Wildlife Aquatic Inventories methods were used to quantify indicators of sediment supply and quality, riparian forest connectivity and health, habitat structure, in-stream complexity, and presence of salmonid species. As part of the overall sampling 47 sites in 1998 and 70 sites in 1999 were sampled on industrial forest lands. Of these sites 13 were sampled both in 1998 and 1999, and 37 sites were sampled for fish presence/absence. Approximately 44% of the sites sampled for habitat were within the range of anadromous salmonids. Upstream catchment area and gradient were the two major factors driving the overall patterns of habitat variables. Secondarily, land ownership and geology were other factors correlated with the habitat variables analyzed. The private non-industrial land ownership type was characterized by slightly higher fine sediment levels, lower wood volumes and number of key wood pieces, lower densities of deep pools, and lower levels of stream shading. State and industrial forest lands show moderate wood levels in the stream channel, although they show low levels of conifers in riparian zones. The sedimentary geologic type was characterized by higher levels of fine sediments in riffle units. Twelve, high quality, unconstrained stream reaches occurred in the 1998 and 1999 habitat sample on Industrial forest lands. Conditions on industrial forest lands in 1998-1999 were compared to conditions in 1993-1994 to detect any potential change over the five-year period. Three different datasets were analyzed. No significant changes in aquatic habitat or riparian conditions were detected. Electrofishing surveys were conducted at 37 sites outside or the expected range of coho salmon to determine fish presence/absence. Salmonid species were present at 19 of the sites that were electrofished. Title: AI - Stream Habitat Conditions on Industrial Forest Lands in Coastal Oregon Abstract -- In the summer of 1998 and 1999, watersheds in western Oregon were randomly sampled for stream habitat conditions. Sites were selected using a random tessellation stratified design. Oregon Department of Fish and Wildlife Aquatic Inventories methods were used to quantify indicators of sediment supply and quality, riparian forest connectivity and health, habitat structure, in-stream complexity, and presence of salmonid species. As part of the overall sampling 47 sites in 1998 and 70 sites in 1999 were sampled on industrial forest lands. Of these sites 13 were sampled both in 1998 and 1999, and 37 sites were sampled for fish presence/absence. Approximately 44% of the sites sampled for habitat were within the range of anadromous salmonids. Upstream catchment area and gradient were the two major factors driving the overall patterns of habitat variables. Secondarily, land ownership and geology were other factors correlated with the habitat variables analyzed. The private non-industrial land ownership type was characterized by slightly higher fine sediment levels, lower wood volumes and number of key wood pieces, lower densities of deep pools, and lower levels of stream shading. State and industrial forest lands show moderate wood levels in the stream channel, although they show low levels of conifers in riparian zones. The sedimentary geologic type was characterized by higher levels of fine sediments in riffle units. Twelve, high quality, unconstrained stream reaches occurred in the 1998 and 1999 habitat sample on Industrial forest lands. Conditions on industrial forest lands in 1998-1999 were compared to conditions in 1993-1994 to detect any potential change over the five-year period. Three different datasets were analyzed. No significant changes in aquatic habitat or riparian conditions were detected. Electrofishing surveys were conducted at 37 sites outside or the expected range of coho salmon to determine fish presence/absence. Salmonid species were present at 19 of the sites that were electrofished. Close

• 7. [Article] Shoreside Hake Observation Program: 2006 Annual Report

  Abstract -- The Shoreside Hake Observation Program (SHOP) was established in 1992 to provide information for monitoring catch in the shoreside component of the directed Pacific hake – also called Pacific ...

  Citation × Citation Citation Abstract Copy Title: Shoreside Hake Observation Program: 2006 Annual Report Abstract -- The Shoreside Hake Observation Program (SHOP) was established in 1992 to provide information for monitoring catch in the shoreside component of the directed Pacific hake – also called Pacific whiting – (Merluccius productus) fishery, and for evaluating conservation measures adopted to limit the catch of salmon, other groundfish, and other prohibited species. Though instituted as an experimental full retention monitoring program, it has been continued annually to account for all catch landed at shoreside processors by targeted hake trips; tracking potential discards, and accommodating the landing and disposal of un-sorted catch from these trips until permanent federal regulations can be developed. The SHOP is a cooperative effort between the fishing industry and state and federal management agencies. Participants in the SHOP include mid-water trawlers carrying Exempted Fishing Permits (EFP), designated shoreside processing plants in California, Oregon, and Washington, the Pacific Fishery Management Council (PFMC), the National Marine Fisheries Service (NMFS), the Pacific States Marine Fisheries Commission (PSMFC), the Oregon Department of Fish and Wildlife (ODFW), the California Department of Fish and Game (CDFG), and the Washington Department of Fish and Wildlife (WDFW). In 1995, the SHOP’s required observation rate was reduced from 50 percent of landings to 10 percent, as studies indicated that fish tickets were a good representation of what was actually landed (ODFW 1995). This lower observation rate allowed for increased collection of biological information (e.g., otoliths, length, weight, sex, and maturity) from Pacific hake and bycatch species such as yellowtail rockfish (Sebastes flavidus), widow rockfish (S. entomelas), yelloweye rockfish (S. ruberrimus), darkblotched rockfish (S. crameri), bocaccio (S. paucispinis), canary rockfish (S. pinniger), sablefish (Anoplopoma fimbria), Pacific (chub) mackerel (Scomber japonicus), and jack mackerel (Trachurus symmetricus). Title: Shoreside Hake Observation Program: 2006 Annual Report Abstract -- The Shoreside Hake Observation Program (SHOP) was established in 1992 to provide information for monitoring catch in the shoreside component of the directed Pacific hake – also called Pacific whiting – (Merluccius productus) fishery, and for evaluating conservation measures adopted to limit the catch of salmon, other groundfish, and other prohibited species. Though instituted as an experimental full retention monitoring program, it has been continued annually to account for all catch landed at shoreside processors by targeted hake trips; tracking potential discards, and accommodating the landing and disposal of un-sorted catch from these trips until permanent federal regulations can be developed. The SHOP is a cooperative effort between the fishing industry and state and federal management agencies. Participants in the SHOP include mid-water trawlers carrying Exempted Fishing Permits (EFP), designated shoreside processing plants in California, Oregon, and Washington, the Pacific Fishery Management Council (PFMC), the National Marine Fisheries Service (NMFS), the Pacific States Marine Fisheries Commission (PSMFC), the Oregon Department of Fish and Wildlife (ODFW), the California Department of Fish and Game (CDFG), and the Washington Department of Fish and Wildlife (WDFW). In 1995, the SHOP’s required observation rate was reduced from 50 percent of landings to 10 percent, as studies indicated that fish tickets were a good representation of what was actually landed (ODFW 1995). This lower observation rate allowed for increased collection of biological information (e.g., otoliths, length, weight, sex, and maturity) from Pacific hake and bycatch species such as yellowtail rockfish (Sebastes flavidus), widow rockfish (S. entomelas), yelloweye rockfish (S. ruberrimus), darkblotched rockfish (S. crameri), bocaccio (S. paucispinis), canary rockfish (S. pinniger), sablefish (Anoplopoma fimbria), Pacific (chub) mackerel (Scomber japonicus), and jack mackerel (Trachurus symmetricus). Close

• 8. [Article] AI - Rearing of Juvenile Salmon in Recovering Wetlands of the Salmon River Estuary

  Abstract -- The Salmon River estuary, on the central Oregon coast, provides an excellent opportunity to study salmonid use of restored tidal marsh. The U.S. Forest Service manages the estuary as part of ...

  Citation × Citation Citation Abstract Copy Title: AI - Rearing of Juvenile Salmon in Recovering Wetlands of the Salmon River Estuary Abstract -- The Salmon River estuary, on the central Oregon coast, provides an excellent opportunity to study salmonid use of restored tidal marsh. The U.S. Forest Service manages the estuary as part of the Cascade Head Scenic Research Area with the goal to rehabilitate the estuary “to its condition prior to the existing diking and agricultural use.” To achieve this goal, the U.S. Forest Service has completed three dike removal projects at 9-year intervals beginning in 1978. These projects created a patchwork of restored marshes in various stages of recovery, providing a natural laboratory for studying marsh restoration processes and their effects on estuarine rearing salmonids. Our Sea Grant-funded research, which is a cooperative study with researchers from the University of Washington, has four objectives: (1) describe salmon species use of undiked reference and recovering marshes; (2) compare diets of juvenile salmon among reference and diked marshes of different recovery ages; (3) compare availability and distribution of prey organisms consumed by juvenile salmon; and (4) assess geomorphological and ecological indicators (“metrics”) of restored wetlands and relationships to salmon use. This report describes the results of fish distribution and abundance surveys. Results of the other objectives are described in Gray et al. (In Review). Title: AI - Rearing of Juvenile Salmon in Recovering Wetlands of the Salmon River Estuary Abstract -- The Salmon River estuary, on the central Oregon coast, provides an excellent opportunity to study salmonid use of restored tidal marsh. The U.S. Forest Service manages the estuary as part of the Cascade Head Scenic Research Area with the goal to rehabilitate the estuary “to its condition prior to the existing diking and agricultural use.” To achieve this goal, the U.S. Forest Service has completed three dike removal projects at 9-year intervals beginning in 1978. These projects created a patchwork of restored marshes in various stages of recovery, providing a natural laboratory for studying marsh restoration processes and their effects on estuarine rearing salmonids. Our Sea Grant-funded research, which is a cooperative study with researchers from the University of Washington, has four objectives: (1) describe salmon species use of undiked reference and recovering marshes; (2) compare diets of juvenile salmon among reference and diked marshes of different recovery ages; (3) compare availability and distribution of prey organisms consumed by juvenile salmon; and (4) assess geomorphological and ecological indicators (“metrics”) of restored wetlands and relationships to salmon use. This report describes the results of fish distribution and abundance surveys. Results of the other objectives are described in Gray et al. (In Review). Close

• 9. [Article] Fish Population Monitoring in the Middle Fork John Day River Intensively Monitored Watershed - Annual Technical Report 2011

  Abstract -- Within the Middle Fork John Day River IMW (MFJDR_IMW), several habitat factors have been identified as limiting for the recovery of summer steelhead. Degraded floodplain and channel structure, ...

  Citation × Citation Citation Abstract Copy Title: Fish Population Monitoring in the Middle Fork John Day River Intensively Monitored Watershed - Annual Technical Report 2011 Abstract -- Within the Middle Fork John Day River IMW (MFJDR_IMW), several habitat factors have been identified as limiting for the recovery of summer steelhead. Degraded floodplain and channel structure, altered sediment routing, altered hydrology, and water quality (temperature) are cited as limiting factors in the Draft Mid-Columbia Steelhead Recovery Plan (Carmichael 2008). Current and proposed restoration efforts for the MFJDR_IMW are anticipated to address these key limiting factors. In order to assess restoration effectiveness on focal fish species, monitoring and analyses must emphasize population level spatial scales. Fish population monitoring for the MFDJR_IMW includes evaluating summer steelhead and spring Chinook population productivity, survival, and abundance. While abundance is an important metric for population assessments, survival and production will also be key indicators of population responses to planned restoration activities. Freshwater survival is assessed from the parr to smolt life stages (parr to smolt survival) and ocean or out-of-basin survival is estimated as a smolt to adult return ratio (SAR). Freshwater productivity is assessed as smolts produced for constructed redds (smolts/redd). ODFW, Eastern Oregon fish Research (EOFR). Funded by Oregon Watershed Enhancement Board (OWEB). Title: Fish Population Monitoring in the Middle Fork John Day River Intensively Monitored Watershed - Annual Technical Report 2011 Abstract -- Within the Middle Fork John Day River IMW (MFJDR_IMW), several habitat factors have been identified as limiting for the recovery of summer steelhead. Degraded floodplain and channel structure, altered sediment routing, altered hydrology, and water quality (temperature) are cited as limiting factors in the Draft Mid-Columbia Steelhead Recovery Plan (Carmichael 2008). Current and proposed restoration efforts for the MFJDR_IMW are anticipated to address these key limiting factors. In order to assess restoration effectiveness on focal fish species, monitoring and analyses must emphasize population level spatial scales. Fish population monitoring for the MFDJR_IMW includes evaluating summer steelhead and spring Chinook population productivity, survival, and abundance. While abundance is an important metric for population assessments, survival and production will also be key indicators of population responses to planned restoration activities. Freshwater survival is assessed from the parr to smolt life stages (parr to smolt survival) and ocean or out-of-basin survival is estimated as a smolt to adult return ratio (SAR). Freshwater productivity is assessed as smolts produced for constructed redds (smolts/redd). ODFW, Eastern Oregon fish Research (EOFR). Funded by Oregon Watershed Enhancement Board (OWEB). Close

• 10. [Article] Fish Population Monitoring in the Middle Fork John Day River Intensively Monitored Watershed - Annual Technical Report 2013-2015

  Abstract -- Within the Middle Fork John Day River IMW (MFJDR_IMW), several habitat factors have been identified as limiting for the recovery of summer steelhead. Degraded floodplain and channel structure, ...

  Citation × Citation Citation Abstract Copy Title: Fish Population Monitoring in the Middle Fork John Day River Intensively Monitored Watershed - Annual Technical Report 2013-2015 Abstract -- Within the Middle Fork John Day River IMW (MFJDR_IMW), several habitat factors have been identified as limiting for the recovery of summer steelhead. Degraded floodplain and channel structure, altered sediment routing, altered hydrology, and water quality (temperature) are cited as limiting factors in the Draft Mid-Columbia Steelhead Recovery Plan (Carmichael 2008). Current and proposed restoration efforts for the MFJDR_IMW are anticipated to address these key limiting factors. In order to assess restoration effectiveness on focal fish species, monitoring and analyses must emphasize population level spatial scales. Fish population monitoring for the MFDJR_IMW includes evaluating summer steelhead and spring Chinook population productivity, survival, and abundance. While abundance is an important metric for population assessments, survival and production will also be key indicators of population responses to planned restoration activities. Freshwater survival is assessed from the parr to smolt life stages (parr to smolt survival) and ocean or out-of-basin survival is estimated as a smolt to adult return ratio (SAR). Freshwater productivity is assessed as smolts produced for constructed redds (smolts/redd). Originator: ODFW, Eastern Oregon Fish Research (EOFR). Funded by Oregon Watershed Enhancement Board (OWEB). Title: Fish Population Monitoring in the Middle Fork John Day River Intensively Monitored Watershed - Annual Technical Report 2013-2015 Abstract -- Within the Middle Fork John Day River IMW (MFJDR_IMW), several habitat factors have been identified as limiting for the recovery of summer steelhead. Degraded floodplain and channel structure, altered sediment routing, altered hydrology, and water quality (temperature) are cited as limiting factors in the Draft Mid-Columbia Steelhead Recovery Plan (Carmichael 2008). Current and proposed restoration efforts for the MFJDR_IMW are anticipated to address these key limiting factors. In order to assess restoration effectiveness on focal fish species, monitoring and analyses must emphasize population level spatial scales. Fish population monitoring for the MFDJR_IMW includes evaluating summer steelhead and spring Chinook population productivity, survival, and abundance. While abundance is an important metric for population assessments, survival and production will also be key indicators of population responses to planned restoration activities. Freshwater survival is assessed from the parr to smolt life stages (parr to smolt survival) and ocean or out-of-basin survival is estimated as a smolt to adult return ratio (SAR). Freshwater productivity is assessed as smolts produced for constructed redds (smolts/redd). Originator: ODFW, Eastern Oregon Fish Research (EOFR). Funded by Oregon Watershed Enhancement Board (OWEB). Close