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• 11. [Article] Sandy beach surf zones: An alternative nursery habitat for 0-age Chinook salmon

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/estuarine-coasta...

  Citation × Citation Citation Abstract Copy Title: Sandy beach surf zones: An alternative nursery habitat for 0-age Chinook salmon Author: Miller, J. A., Marin Jarrin, J. R. This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/estuarine-coastal-and-shelf-science/. Title: Sandy beach surf zones: An alternative nursery habitat for 0-age Chinook salmon Author: Miller, J. A., Marin Jarrin, J. R. This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/estuarine-coastal-and-shelf-science/. Close

• 12. [Article] Sandy beach surf zones : what is their role in the early life history of Chinook salmon (Oncorhynchus tshawytscha)?

  Early life stages of many marine and diadromous fish species use sandy beach surf zones, which occur along >50% of the world's marine coastlines. This extensive habitat can provide juvenile fishes with ...

  Citation × Citation Citation Abstract Copy Title: Sandy beach surf zones : what is their role in the early life history of Chinook salmon (Oncorhynchus tshawytscha)? Author: Marin Jarrin, Jose R., 1980- Early life stages of many marine and diadromous fish species use sandy beach surf zones, which occur along >50% of the world's marine coastlines. This extensive habitat can provide juvenile fishes with an abundant supply of potential prey and the ability to hide from predators in its shallow turbid waters. Chinook salmon is an anadromous species that migrates to the ocean during their first (subyearlings) or second (yearlings) year of life. The majority of subyearlings reside in estuaries during their first summer season; however, a small number of juveniles also use surf zones. Early marine residence is considered a critical period for Chinook salmon due to high mortality rates; however the role of surf zones in Chinook salmon life history is unclear. Therefore, I determined the distribution of juvenile Chinook salmon on beaches of the eastern North Pacific, compared the migration and growth patterns observed in surf zones and estuaries, identified the factors that accounted for variation in juvenile surf zone catch, explored the factors that influence growth rate variation in surf zones and estuaries, and modeled how growth rates in these coastal habitats may vary in the near future with predicted changes in climate. The majority (94%) of juveniles were caught in surf zones adjacent to estuaries with trough areas, which are beach sections where sand moved by currents and waves produce a trench-like shape. Surf zone fish were collected in significantly lower numbers than estuarine juveniles but entered brackish/ocean waters at similar sizes. Juveniles in surf zones consumed similar organisms (gammarid amphipods, crustacean larvae and insects) as in estuaries. Furthermore, stomach fullness indices (average = 2% of body weight) and growth rates (average = 0.4 mm day⁻¹) were similar in surf zones and estuaries. At one surf zone, juvenile catch was positively correlated to short-term specific growth rates (14 days prior to capture). A bioenergetics modeling approach indicated that given current conditions, consumption rates accounted for more of the variation in growth than prey energetic content and temperature. Climate models predict future increases in fresh water temperature (1.5 to 5.8°C), sea surface temperature (1.2°C) and wave height (0.75 m) that could influence estuarine and surf zone use. Therefore, I developed a local mixing model based on these predictions to estimate future surf zone and estuarine water temperatures in two of the watersheds studied. Based on these temperature projections and the bioenergetics model, I predicted how juvenile specific growth rates would vary in both habitats. I determined that increases in water temperature in both habitats would reduce specific growth rates by 9 to 40% in surf zones and estuaries if diet composition and consumption rates remain similar to present conditions. To compensate for the decline in growth, juveniles may increase their consumption rates or consume more energetically rich prey, if available. If they are not able to compensate, their size at the end of the season may be reduced, which could reduce their overall survival. These results confirm that a small number of suyearling Chinook salmon use sandy beach surf zones, mostly adjacent to estuary mouths, where they experience growth conditions comparable to estuaries. My findings indicate that, in certain situations, juvenile Chinook salmon surf zone use can be influenced by surf zone growth conditions, while variation in growth rates are themselves most strongly influenced by variation in consumption rates in surf zones and estuaries. Predicted changes in coastal western North American climate will likely modify juvenile growth conditions in the next 50 years, and potentially reduce overall survival. Additional insights into the potential impacts of climate change on juvenile salmon will require estimates of changes in the composition, energetic quality and abundance of prey communities inhabiting coastal environments. Title: Sandy beach surf zones : what is their role in the early life history of Chinook salmon (Oncorhynchus tshawytscha)? Author: Marin Jarrin, Jose R., 1980- Early life stages of many marine and diadromous fish species use sandy beach surf zones, which occur along >50% of the world's marine coastlines. This extensive habitat can provide juvenile fishes with an abundant supply of potential prey and the ability to hide from predators in its shallow turbid waters. Chinook salmon is an anadromous species that migrates to the ocean during their first (subyearlings) or second (yearlings) year of life. The majority of subyearlings reside in estuaries during their first summer season; however, a small number of juveniles also use surf zones. Early marine residence is considered a critical period for Chinook salmon due to high mortality rates; however the role of surf zones in Chinook salmon life history is unclear. Therefore, I determined the distribution of juvenile Chinook salmon on beaches of the eastern North Pacific, compared the migration and growth patterns observed in surf zones and estuaries, identified the factors that accounted for variation in juvenile surf zone catch, explored the factors that influence growth rate variation in surf zones and estuaries, and modeled how growth rates in these coastal habitats may vary in the near future with predicted changes in climate. The majority (94%) of juveniles were caught in surf zones adjacent to estuaries with trough areas, which are beach sections where sand moved by currents and waves produce a trench-like shape. Surf zone fish were collected in significantly lower numbers than estuarine juveniles but entered brackish/ocean waters at similar sizes. Juveniles in surf zones consumed similar organisms (gammarid amphipods, crustacean larvae and insects) as in estuaries. Furthermore, stomach fullness indices (average = 2% of body weight) and growth rates (average = 0.4 mm day⁻¹) were similar in surf zones and estuaries. At one surf zone, juvenile catch was positively correlated to short-term specific growth rates (14 days prior to capture). A bioenergetics modeling approach indicated that given current conditions, consumption rates accounted for more of the variation in growth than prey energetic content and temperature. Climate models predict future increases in fresh water temperature (1.5 to 5.8°C), sea surface temperature (1.2°C) and wave height (0.75 m) that could influence estuarine and surf zone use. Therefore, I developed a local mixing model based on these predictions to estimate future surf zone and estuarine water temperatures in two of the watersheds studied. Based on these temperature projections and the bioenergetics model, I predicted how juvenile specific growth rates would vary in both habitats. I determined that increases in water temperature in both habitats would reduce specific growth rates by 9 to 40% in surf zones and estuaries if diet composition and consumption rates remain similar to present conditions. To compensate for the decline in growth, juveniles may increase their consumption rates or consume more energetically rich prey, if available. If they are not able to compensate, their size at the end of the season may be reduced, which could reduce their overall survival. These results confirm that a small number of suyearling Chinook salmon use sandy beach surf zones, mostly adjacent to estuary mouths, where they experience growth conditions comparable to estuaries. My findings indicate that, in certain situations, juvenile Chinook salmon surf zone use can be influenced by surf zone growth conditions, while variation in growth rates are themselves most strongly influenced by variation in consumption rates in surf zones and estuaries. Predicted changes in coastal western North American climate will likely modify juvenile growth conditions in the next 50 years, and potentially reduce overall survival. Additional insights into the potential impacts of climate change on juvenile salmon will require estimates of changes in the composition, energetic quality and abundance of prey communities inhabiting coastal environments. Close

• 13. [Article] Evaluating "nuisance" beaver relocation as a tool to increase coho salmon habitat in the Alsea Basin of the central Oregon Coast Range

  Many stakeholders involved with stream restoration in the Pacific Northwest have discussed the potential benefits of using beaver dam construction activities (Castor canadensis) as a management tool to ...

  Citation × Citation Citation Abstract Copy Title: Evaluating "nuisance" beaver relocation as a tool to increase coho salmon habitat in the Alsea Basin of the central Oregon Coast Range Author: Petro, Vanessa M. Many stakeholders involved with stream restoration in the Pacific Northwest have discussed the potential benefits of using beaver dam construction activities (Castor canadensis) as a management tool to improve degraded stream habitat for anadromous salmon species. In addition, there has been growing interest in using nuisance beavers, primarily controlled by lethal methods, to alleviate human-wildlife conflict issues and subsequently improve Coho salmon (Oncorhynchus kisutch) rearing habitat. To understand the efficacy of using beavers as a stream restoration tool, I studied the movement, survival, and dam construction of nuisance beavers relocated to the Alsea Basin of the Oregon Coast Range. I trapped and transported 38 individuals to the nine release sites where dams constructed by beavers would benefit coho salmon productivity. All adult and sub-adult beavers were equipped with tail-mount transmitters. Beavers moved an average of 3.3 ± 0.2 (SE) stream km from release sites. The maximum distance moved from a release site was 29.2 stream km. Post-release movements did not differ significantly by age or sex. All radio-tagged individuals dispersed from their release sites. Survival 16 weeks post-release was 47%. Twelve of the radio-tagged beavers died within 90 days of release. Three cause-specific sources of mortality were identified including predation, natural causes, and human related. Mountain lions (Puma concolor) were responsible for the majority of predation based mortalities. Of the 38 nuisance beavers relocated, only five individuals contributed to the nine dams constructed post-release. Six of these dams were built by one male: female pair. All dams constructed by relocated beavers were ephemeral. In addition to monitoring post-release beaver responses, I also assessed the utility of pre-existing models to identify release site locations. Thus, I explored dam habitat relationships of extant and relocated colonies throughout the Alsea Basin. I determined the utility of locally developed spatial models was reasonable. Analysis revealed primary pool habitat and valley floor width variables as strong indicators of beaver dam sites. I conclude beaver relocation as a tool for stream restoration in the Alsea Basin may not offer an effective solution to lethal control measures and coho habitat enhancement due to low survival rates, unwanted movement and establishment outside of suitable release sites, and lack of dam construction. Title: Evaluating "nuisance" beaver relocation as a tool to increase coho salmon habitat in the Alsea Basin of the central Oregon Coast Range Author: Petro, Vanessa M. Many stakeholders involved with stream restoration in the Pacific Northwest have discussed the potential benefits of using beaver dam construction activities (Castor canadensis) as a management tool to improve degraded stream habitat for anadromous salmon species. In addition, there has been growing interest in using nuisance beavers, primarily controlled by lethal methods, to alleviate human-wildlife conflict issues and subsequently improve Coho salmon (Oncorhynchus kisutch) rearing habitat. To understand the efficacy of using beavers as a stream restoration tool, I studied the movement, survival, and dam construction of nuisance beavers relocated to the Alsea Basin of the Oregon Coast Range. I trapped and transported 38 individuals to the nine release sites where dams constructed by beavers would benefit coho salmon productivity. All adult and sub-adult beavers were equipped with tail-mount transmitters. Beavers moved an average of 3.3 ± 0.2 (SE) stream km from release sites. The maximum distance moved from a release site was 29.2 stream km. Post-release movements did not differ significantly by age or sex. All radio-tagged individuals dispersed from their release sites. Survival 16 weeks post-release was 47%. Twelve of the radio-tagged beavers died within 90 days of release. Three cause-specific sources of mortality were identified including predation, natural causes, and human related. Mountain lions (Puma concolor) were responsible for the majority of predation based mortalities. Of the 38 nuisance beavers relocated, only five individuals contributed to the nine dams constructed post-release. Six of these dams were built by one male: female pair. All dams constructed by relocated beavers were ephemeral. In addition to monitoring post-release beaver responses, I also assessed the utility of pre-existing models to identify release site locations. Thus, I explored dam habitat relationships of extant and relocated colonies throughout the Alsea Basin. I determined the utility of locally developed spatial models was reasonable. Analysis revealed primary pool habitat and valley floor width variables as strong indicators of beaver dam sites. I conclude beaver relocation as a tool for stream restoration in the Alsea Basin may not offer an effective solution to lethal control measures and coho habitat enhancement due to low survival rates, unwanted movement and establishment outside of suitable release sites, and lack of dam construction. Close

• 14. [Article] Policy Patterns across Riverscapes : Riparian Land Standards in the Oregon Coast Range

  Land management policies are ideas about nature projected onto the landscape. Culminations of social, economic, and scientific influences, these policies create standards affecting the function of ecological ...

  Citation × Citation Citation Abstract Copy Title: Policy Patterns across Riverscapes : Riparian Land Standards in the Oregon Coast Range Author: Boisjolie, Brett A. Land management policies are ideas about nature projected onto the landscape. Culminations of social, economic, and scientific influences, these policies create standards affecting the function of ecological systems. In the case of riparian lands in the Oregon Coast Range, policy requirements vary considerably across federal, state, and private land ownerships. Protective measures, such as the adoption of fixed buffer widths for maintaining vegetation, are intended to preserve natural processes important to instream habitat and water quality. However, the "policy landscape" of variable management standards can result in a fragmented approach to policy protection. This fragmentation complicates recovery efforts for threatened anadromous fish species such as coho salmon (Oncorhynchus kisutch), which require connectivity in suitable habitat segments throughout the river network. Taking a riverscape perspective, this study evaluates how aquatic protections vary across the river and its valley. To explore the patterns created from variable standard, the study first delineates categories of riparian management standards in the Oregon Coast Range. Using a geographic information system (GIS), these standards are mapped across the river networks of this region. The extent of each policy category is quantified in stream kilometers in order to evaluate policy efforts within and across the riverscapes of the Oregon Coast Range. A model of intrinsic potential for coho salmon habitat is used to identify the policy standards in stream reaches where flow, valley constraint, and channel gradient are appropriate for coho salmon habitat. A second model of the stream network (hydrography) is developed to evaluate how differences in stream delineation can influence policy patterns. Results indicate that riparian lands of the Oregon Coast Range are protected by variable standards for land management, including buffer widths that range from 0 to ~152m. In streams important to coho salmon, a lower proportion of the stream network was found to be protected by policy standards compared to the watershed and ESU scale. A lack of stream data central to policy application (fish use, stream flow duration, mean annual flow, water use) complicated our ability to attribute stream segments with specific land management requirements. The choice of hydrographic data was also found to influence the proportional extent of policies within riverscapes. This framework for assessing the spatial distribution of policies can provide insights for future studies of riverscape systems. Title: Policy Patterns across Riverscapes : Riparian Land Standards in the Oregon Coast Range Author: Boisjolie, Brett A. Land management policies are ideas about nature projected onto the landscape. Culminations of social, economic, and scientific influences, these policies create standards affecting the function of ecological systems. In the case of riparian lands in the Oregon Coast Range, policy requirements vary considerably across federal, state, and private land ownerships. Protective measures, such as the adoption of fixed buffer widths for maintaining vegetation, are intended to preserve natural processes important to instream habitat and water quality. However, the "policy landscape" of variable management standards can result in a fragmented approach to policy protection. This fragmentation complicates recovery efforts for threatened anadromous fish species such as coho salmon (Oncorhynchus kisutch), which require connectivity in suitable habitat segments throughout the river network. Taking a riverscape perspective, this study evaluates how aquatic protections vary across the river and its valley. To explore the patterns created from variable standard, the study first delineates categories of riparian management standards in the Oregon Coast Range. Using a geographic information system (GIS), these standards are mapped across the river networks of this region. The extent of each policy category is quantified in stream kilometers in order to evaluate policy efforts within and across the riverscapes of the Oregon Coast Range. A model of intrinsic potential for coho salmon habitat is used to identify the policy standards in stream reaches where flow, valley constraint, and channel gradient are appropriate for coho salmon habitat. A second model of the stream network (hydrography) is developed to evaluate how differences in stream delineation can influence policy patterns. Results indicate that riparian lands of the Oregon Coast Range are protected by variable standards for land management, including buffer widths that range from 0 to ~152m. In streams important to coho salmon, a lower proportion of the stream network was found to be protected by policy standards compared to the watershed and ESU scale. A lack of stream data central to policy application (fish use, stream flow duration, mean annual flow, water use) complicated our ability to attribute stream segments with specific land management requirements. The choice of hydrographic data was also found to influence the proportional extent of policies within riverscapes. This framework for assessing the spatial distribution of policies can provide insights for future studies of riverscape systems. Close

• 15. [Article] The influence of sex, migration distance, and latitude on expression of anadromy in Oncorhynchus mykiss

  The evolution and maintenance of multiple phenotypes within populations is an interesting evolutionary and ecological question, and is becoming increasingly important for the restoration and conservation ...

  Citation × Citation Citation Abstract Copy Title: The influence of sex, migration distance, and latitude on expression of anadromy in Oncorhynchus mykiss Author: Ohms, Haley The evolution and maintenance of multiple phenotypes within populations is an interesting evolutionary and ecological question, and is becoming increasingly important for the restoration and conservation of partially migratory species. In particular, why individuals adopt a particular phenotype has been the focus of numerous research efforts. In the partially migratory species Oncorhynchys mykiss (commonly known as steelhead and rainbow trout), I found that sex plays a strong role in whether an individual adopts an anadromous or resident life history. I observed a higher frequency of females adopting the anadromous tactic throughout the species range, and I attributed this to the relationship between body size and reproductive success in females that is not present in males. I did not observe differences in female bias along gradients of latitude or migration distance, and I hypothesize that while the frequency of tactics among populations may change along these gradients, either the change is equal between males and females, or an interaction of latitude and migration distance may control changes. I did not observe a corresponding male bias in the one resident population I sampled, and suggest that this is the result of a high frequency of residents in that population. I propose that sex ratios could be a valuable metric for measuring frequency of life-history tactics in populations and could facilitate the investigation into the controls of life-history tactics across broad scales. Title: The influence of sex, migration distance, and latitude on expression of anadromy in Oncorhynchus mykiss Author: Ohms, Haley The evolution and maintenance of multiple phenotypes within populations is an interesting evolutionary and ecological question, and is becoming increasingly important for the restoration and conservation of partially migratory species. In particular, why individuals adopt a particular phenotype has been the focus of numerous research efforts. In the partially migratory species Oncorhynchys mykiss (commonly known as steelhead and rainbow trout), I found that sex plays a strong role in whether an individual adopts an anadromous or resident life history. I observed a higher frequency of females adopting the anadromous tactic throughout the species range, and I attributed this to the relationship between body size and reproductive success in females that is not present in males. I did not observe differences in female bias along gradients of latitude or migration distance, and I hypothesize that while the frequency of tactics among populations may change along these gradients, either the change is equal between males and females, or an interaction of latitude and migration distance may control changes. I did not observe a corresponding male bias in the one resident population I sampled, and suggest that this is the result of a high frequency of residents in that population. I propose that sex ratios could be a valuable metric for measuring frequency of life-history tactics in populations and could facilitate the investigation into the controls of life-history tactics across broad scales. Close

• 16. [Article] The Umpqua River study : a joint report

  The species of anadromous fish entering the Umpqua River are: chinook salmon (spring, summer, and fall runs), silver salmon, steelhead trout (summer and winter runs), cutthroat trout, shad, striped bass ...

  Citation × Citation Citation Abstract Copy Title: The Umpqua River study : a joint report Author: Oregon. State Game Commission, Oregon. Fish Commission The species of anadromous fish entering the Umpqua River are: chinook salmon (spring, summer, and fall runs), silver salmon, steelhead trout (summer and winter runs), cutthroat trout, shad, striped bass and sturgeon. The winter steelhead, striped bass, and shad runs appear to be maintaining themselves. The runs of the other species appear to be in various stages of depletion. Major factors which have contributed to this depletion are: overfishing by the commercial fishery and more recently the sport fishery; and barriers such as log jams, "splash" damns, mill dam and hydroelectric developments. Other factors which may be of importance are: predation; unscreened gravity water diversions; water removal by pumping for irrigation, industrial, and municipal use; and fluctuations in water levels due to meterological conditions. The total run of spring chinook salmon into the Umpqua River in 1946 was estimated to be 4,400 fish of which approximately 935 were jacks. (fish under 20 inches). The fishing mortality of shad of commercial size, in the 1946 Umpqua River run, was estimated to be 50 percent. The total catch of the various species of salmon by the commercial and sport fisheries in 1946 were as follows: Under a proper management program, an average sustained yield of several times in the 1946 catches may be expected. During 1946, anglers spent at least $292,700 in this area while fishing for salmon and trout in the Umpqua River. The capital investment was estimated to be $2,402,500. The commercial fishery products of salmon steelhead, shad, striped bass, pilchards, and crabs taken from the Umpqua River in 1946 had a wholesale valur of $652,400. The capital investment was not determined. Title: The Umpqua River study : a joint report Author: Oregon. State Game Commission, Oregon. Fish Commission The species of anadromous fish entering the Umpqua River are: chinook salmon (spring, summer, and fall runs), silver salmon, steelhead trout (summer and winter runs), cutthroat trout, shad, striped bass and sturgeon. The winter steelhead, striped bass, and shad runs appear to be maintaining themselves. The runs of the other species appear to be in various stages of depletion. Major factors which have contributed to this depletion are: overfishing by the commercial fishery and more recently the sport fishery; and barriers such as log jams, "splash" damns, mill dam and hydroelectric developments. Other factors which may be of importance are: predation; unscreened gravity water diversions; water removal by pumping for irrigation, industrial, and municipal use; and fluctuations in water levels due to meterological conditions. The total run of spring chinook salmon into the Umpqua River in 1946 was estimated to be 4,400 fish of which approximately 935 were jacks. (fish under 20 inches). The fishing mortality of shad of commercial size, in the 1946 Umpqua River run, was estimated to be 50 percent. The total catch of the various species of salmon by the commercial and sport fisheries in 1946 were as follows: Under a proper management program, an average sustained yield of several times in the 1946 catches may be expected. During 1946, anglers spent at least $292,700 in this area while fishing for salmon and trout in the Umpqua River. The capital investment was estimated to be $2,402,500. The commercial fishery products of salmon steelhead, shad, striped bass, pilchards, and crabs taken from the Umpqua River in 1946 had a wholesale valur of $652,400. The capital investment was not determined. Close

• 17. [Article] Aspects of the early life history of juvenile salmonids in the Dungeness River Estuary

  The decline of many Pacific salmon stocks has stimulated interest in the early life history and habitat requirements of juvenile salmon. Although estuarine habitat associations of juvenile salmon have ...

  Citation × Citation Citation Abstract Copy Title: Aspects of the early life history of juvenile salmonids in the Dungeness River Estuary Author: Sather, Nichole K. The decline of many Pacific salmon stocks has stimulated interest in the early life history and habitat requirements of juvenile salmon. Although estuarine habitat associations of juvenile salmon have been investigated in many coastal areas of the eastern Pacific Ocean, until recently, little was known about juvenile salmonid ecology within the Straits of Juan de Fuca. During the Spring/Summer outmigration period in 2006 and 2007, I examined the early life history of the five species of anadromous salmon in the Dungeness River estuary on the north Olympic Peninsula, Washington. I sampled multiple spatial scales within several habitat types to characterize salmon distribution and habitat use. My results presented in this thesis are segregated into two components: 1) tidal marsh ecology of juvenile salmonids in the Dungeness River estuary, and 2) the landscape-scale distribution of juvenile salmonids within the Dungeness River estuary. I examined the population of juvenile salmonids within blind tidal sloughs near the vicinity of the Dungeness River delta. Salmonids were present within the tidal marshes throughout the entire outmigration period (e.g., March through July). Juvenile Chinook salmon (Oncorhynchus tshawytscha) were the most abundant salmonid species within the marshes. Based on the temporal distribution and size structure of juvenile Chinook salmon in the estuary I identified at least four life history types: 1) a fry strategy included a large pulse of fish emigrating from the river at a small size (e.g., 35-45mm FL) during late winter and early spring months; 2) the second group of fish was the least abundant group emigrating from the river from April through mid May at sizes ranging from 50-75mm FL; 3) the third group of migrants entered the estuary between from late spring through the summer months at larger sizes than the initial groups (e.g., 60-90mm FL); and 4) the final group of Chinook salmon included a stream-type yearling strategy. In addition to the four life history strategies identified for Chinook salmon, I detected at least three groups of chum salmon migrating into the estuary. These groups were distinguished by their size and timing of migration and are further described according to different rearing strategies. The distribution of juvenile salmonids was most strongly influenced by the degree of connectivity (i.e., distance) between the tidal marshes and the mouth of the Dungeness River. Habitat complexity and opportunity also governed the distribution of juvenile salmonids within the tidal marshes. I also sampled three regions of the estuary with a beach seine to investigate the nearshore distribution of juvenile salmonids within the Dungeness River estuary: the delta face, inner Bay, and outer Bay. Among the three regions, species composition was highly variable between 2006 and 2007. The most common salmonids encountered within the beach seine sites included Chinook salmon, chum salmon (O. kisutch), and pink salmon (O. gorbuscha). The relative abundance of salmonids was highest near the delta face and lowest within the outer bay area. The landscape-scale distribution and habitat use of juvenile salmonids within the Dungeness River estuary is largely influenced by ecosystem connectivity, but is also linked to biotic characteristics of the fish (e.g., life history type and fish size). Although the Dungeness includes hydrogeomorphic characteristics (e.g., steep river gradient, composition of sand spits in the estuary) unique to other Pacific Northwest watersheds, this system produces a variety of life history types comparable to other estuaries. Understanding the mechanisms that drive the distribution of juvenile salmonids within the Dungeness will supply local resource managers with a baseline with which to establish ecosystem restoration goals. Title: Aspects of the early life history of juvenile salmonids in the Dungeness River Estuary Author: Sather, Nichole K. The decline of many Pacific salmon stocks has stimulated interest in the early life history and habitat requirements of juvenile salmon. Although estuarine habitat associations of juvenile salmon have been investigated in many coastal areas of the eastern Pacific Ocean, until recently, little was known about juvenile salmonid ecology within the Straits of Juan de Fuca. During the Spring/Summer outmigration period in 2006 and 2007, I examined the early life history of the five species of anadromous salmon in the Dungeness River estuary on the north Olympic Peninsula, Washington. I sampled multiple spatial scales within several habitat types to characterize salmon distribution and habitat use. My results presented in this thesis are segregated into two components: 1) tidal marsh ecology of juvenile salmonids in the Dungeness River estuary, and 2) the landscape-scale distribution of juvenile salmonids within the Dungeness River estuary. I examined the population of juvenile salmonids within blind tidal sloughs near the vicinity of the Dungeness River delta. Salmonids were present within the tidal marshes throughout the entire outmigration period (e.g., March through July). Juvenile Chinook salmon (Oncorhynchus tshawytscha) were the most abundant salmonid species within the marshes. Based on the temporal distribution and size structure of juvenile Chinook salmon in the estuary I identified at least four life history types: 1) a fry strategy included a large pulse of fish emigrating from the river at a small size (e.g., 35-45mm FL) during late winter and early spring months; 2) the second group of fish was the least abundant group emigrating from the river from April through mid May at sizes ranging from 50-75mm FL; 3) the third group of migrants entered the estuary between from late spring through the summer months at larger sizes than the initial groups (e.g., 60-90mm FL); and 4) the final group of Chinook salmon included a stream-type yearling strategy. In addition to the four life history strategies identified for Chinook salmon, I detected at least three groups of chum salmon migrating into the estuary. These groups were distinguished by their size and timing of migration and are further described according to different rearing strategies. The distribution of juvenile salmonids was most strongly influenced by the degree of connectivity (i.e., distance) between the tidal marshes and the mouth of the Dungeness River. Habitat complexity and opportunity also governed the distribution of juvenile salmonids within the tidal marshes. I also sampled three regions of the estuary with a beach seine to investigate the nearshore distribution of juvenile salmonids within the Dungeness River estuary: the delta face, inner Bay, and outer Bay. Among the three regions, species composition was highly variable between 2006 and 2007. The most common salmonids encountered within the beach seine sites included Chinook salmon, chum salmon (O. kisutch), and pink salmon (O. gorbuscha). The relative abundance of salmonids was highest near the delta face and lowest within the outer bay area. The landscape-scale distribution and habitat use of juvenile salmonids within the Dungeness River estuary is largely influenced by ecosystem connectivity, but is also linked to biotic characteristics of the fish (e.g., life history type and fish size). Although the Dungeness includes hydrogeomorphic characteristics (e.g., steep river gradient, composition of sand spits in the estuary) unique to other Pacific Northwest watersheds, this system produces a variety of life history types comparable to other estuaries. Understanding the mechanisms that drive the distribution of juvenile salmonids within the Dungeness will supply local resource managers with a baseline with which to establish ecosystem restoration goals. Close

• 18. [Article] The future of the Columbia River salmon fisheries

  The salmon runs of the Columbia River constitute one of the most important natural resources of the states of Oregon and Washington. Thousands of people are dependent, wholly or in part, upon these resources ...

  Citation × Citation Citation Abstract Copy Title: The future of the Columbia River salmon fisheries Author: Oregon. Fish Commission, Rich, Willis H. (Willis Horton), 1885-1972 The salmon runs of the Columbia River constitute one of the most important natural resources of the states of Oregon and Washington. Thousands of people are dependent, wholly or in part, upon these resources for their livelihood; and their welfare is dependent upon the maintenance of the salmon runs. It is to the special interest of these people that the salmon supply be maintained at the level of maximum productivity and, indirectly, it is to the interest of all the citizens of these states that this be done. In recent years it has become increasingly evident that these resources, taken as. a whole, are decreasing in productivity and it has been frequently pointed out that this decrease is due primarily to the operation of two factors-- a very intensive fishery and a reduction in spawning and rearing areas due to the utilization of the water resources of the Columbia basin for other purposes. These influences, however, have affected the several species of salmon that are found in the Columbia River quite differently; the more valuable species, Chinooks and bluebacks, showing more evidence of depletion than do the other species, silver salmon, chums and steelhead. Title: The future of the Columbia River salmon fisheries Author: Oregon. Fish Commission, Rich, Willis H. (Willis Horton), 1885-1972 The salmon runs of the Columbia River constitute one of the most important natural resources of the states of Oregon and Washington. Thousands of people are dependent, wholly or in part, upon these resources for their livelihood; and their welfare is dependent upon the maintenance of the salmon runs. It is to the special interest of these people that the salmon supply be maintained at the level of maximum productivity and, indirectly, it is to the interest of all the citizens of these states that this be done. In recent years it has become increasingly evident that these resources, taken as. a whole, are decreasing in productivity and it has been frequently pointed out that this decrease is due primarily to the operation of two factors-- a very intensive fishery and a reduction in spawning and rearing areas due to the utilization of the water resources of the Columbia basin for other purposes. These influences, however, have affected the several species of salmon that are found in the Columbia River quite differently; the more valuable species, Chinooks and bluebacks, showing more evidence of depletion than do the other species, silver salmon, chums and steelhead. Close

• 19. [Article] Fish Inves 1947 pt 1.pdf

  Citation × Citation Citation Abstract Copy Title: Fish Inves 1947 pt 1.pdf Author: Oregon. State Game Commission Title: Fish Inves 1947 pt 1.pdf Author: Oregon. State Game Commission Close

• 20. [Article] Fish Invest 1946 pt 2.pdf

  Citation × Citation Citation Abstract Copy Title: Fish Invest 1946 pt 2.pdf Author: Oregon. State Game Commission Title: Fish Invest 1946 pt 2.pdf Author: Oregon. State Game Commission Close