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• 1. [Article] Juvenile Rockfish (Sebastes spp.) Community Composition and Habitat use of Yaquina Bay, Oregon

  Estuaries, which provide viable habitat for a plethora of fish and invertebrate species, are being increasingly impacted by anthropogenic and natural forces. Estuaries are important nursery habitat for ...

  Citation × Citation Citation Abstract Copy Title: Juvenile Rockfish (Sebastes spp.) Community Composition and Habitat use of Yaquina Bay, Oregon Author: Lindsley, Amy J. Estuaries, which provide viable habitat for a plethora of fish and invertebrate species, are being increasingly impacted by anthropogenic and natural forces. Estuaries are important nursery habitat for young-of-the-year (YOY) Pacific rockfish (Sebastes spp.). Yaquina Bay, a marine-dominated estuary on the central Oregon Coast, served as a study site for the estuarine use of juvenile rockfishes, and large numbers of juvenile rockfish have been captured in this bay. Nursery habitats must provide rearing habitat, adequate food resources and refuge. A vital but lacking connection in our understanding of estuaries as nursery habitat is how rockfishes use the different microhabitats within an estuarine ecosystem. As habitats structure biotic communities, determining the ecological requirements for juvenile rockfish habitats that minimize mortality, maximize growth and increase population numbers will assist managers and biologists in managing and protecting critical high-quality nursery areas. This study provides insight into Oregon rockfish life history, evaluating the spatial and temporal use of estuarine nursery habitat by juvenile rockfishes. The primary objectives were to (1) determine which species of rockfish utilize Yaquina Bay, (2) determine seasonal variations in abundance, and (3) assess the utilization of natural (eelgrass beds, Zostera marina) versus anthropogenic (piers) estuarine habitat. I conducted a mark-recapture study of juvenile rockfishes to begin to elucidate how these species may be using different habitats in the bay. This study provides evidence for the presence of previously undocumented rockfish species, the overwinter persistence of juvenile rockfish in the estuary, some degree of site fidelity, and apparent minimal movement of juvenile rockfish in the Yaquina Bay estuary during the period of this study, as well as a shift in rockfish community dominance from S. melanops to S. maliger and S. caurinus. The survival and recapture of juveniles in both natural (Z. marina) and anthropogenic (piers) habitat demonstrates rockfishes’ successful use of multiple Yaquina Bay habitat types as nursery grounds year-round. There is seasonal variability in rockfish use of the anthropogenic and natural habitat, with the anthropogenic habitats having an overall higher capture rate and a higher occurrence of larger rockfish. All eight species S. melanops, S. maliger, S. caurinus, S. paucispinis, S. flavidus, S. nebulosus, S. pinniger and S. auriculatus are present in the natural, Z. marina habitat. Sebastes pinniger and S. auriculatus are absent from anthropogenic, pier habitat. The implications of determining habitat parameters, community interactions, seasonal changes of the fish community, and ecosystem mechanisms may be invaluable to support further recreational and commercial fishing and help sustain or increase adult populations. My findings present a significant contribution towards the proper management and conservation of essential habitat for rockfish, a group of species with high commercial value and substantial recreational harvest. Title: Juvenile Rockfish (Sebastes spp.) Community Composition and Habitat use of Yaquina Bay, Oregon Author: Lindsley, Amy J. Estuaries, which provide viable habitat for a plethora of fish and invertebrate species, are being increasingly impacted by anthropogenic and natural forces. Estuaries are important nursery habitat for young-of-the-year (YOY) Pacific rockfish (Sebastes spp.). Yaquina Bay, a marine-dominated estuary on the central Oregon Coast, served as a study site for the estuarine use of juvenile rockfishes, and large numbers of juvenile rockfish have been captured in this bay. Nursery habitats must provide rearing habitat, adequate food resources and refuge. A vital but lacking connection in our understanding of estuaries as nursery habitat is how rockfishes use the different microhabitats within an estuarine ecosystem. As habitats structure biotic communities, determining the ecological requirements for juvenile rockfish habitats that minimize mortality, maximize growth and increase population numbers will assist managers and biologists in managing and protecting critical high-quality nursery areas. This study provides insight into Oregon rockfish life history, evaluating the spatial and temporal use of estuarine nursery habitat by juvenile rockfishes. The primary objectives were to (1) determine which species of rockfish utilize Yaquina Bay, (2) determine seasonal variations in abundance, and (3) assess the utilization of natural (eelgrass beds, Zostera marina) versus anthropogenic (piers) estuarine habitat. I conducted a mark-recapture study of juvenile rockfishes to begin to elucidate how these species may be using different habitats in the bay. This study provides evidence for the presence of previously undocumented rockfish species, the overwinter persistence of juvenile rockfish in the estuary, some degree of site fidelity, and apparent minimal movement of juvenile rockfish in the Yaquina Bay estuary during the period of this study, as well as a shift in rockfish community dominance from S. melanops to S. maliger and S. caurinus. The survival and recapture of juveniles in both natural (Z. marina) and anthropogenic (piers) habitat demonstrates rockfishes’ successful use of multiple Yaquina Bay habitat types as nursery grounds year-round. There is seasonal variability in rockfish use of the anthropogenic and natural habitat, with the anthropogenic habitats having an overall higher capture rate and a higher occurrence of larger rockfish. All eight species S. melanops, S. maliger, S. caurinus, S. paucispinis, S. flavidus, S. nebulosus, S. pinniger and S. auriculatus are present in the natural, Z. marina habitat. Sebastes pinniger and S. auriculatus are absent from anthropogenic, pier habitat. The implications of determining habitat parameters, community interactions, seasonal changes of the fish community, and ecosystem mechanisms may be invaluable to support further recreational and commercial fishing and help sustain or increase adult populations. My findings present a significant contribution towards the proper management and conservation of essential habitat for rockfish, a group of species with high commercial value and substantial recreational harvest. Close

• 2. [Article] Comparing Metacarcinus magister settlement preferences among the seagrasses Zostera marina and Zostera japonica

  Metacarcinus magister, the Dungeness crab, is a commercially important species on the Pacific Northwest coast as the most profitable fishery in Oregon and an important ecological player as both predator ...

  Citation × Citation Citation Abstract Copy Title: Comparing Metacarcinus magister settlement preferences among the seagrasses Zostera marina and Zostera japonica Author: Heidmann, Sarah, Jaco, Erin Metacarcinus magister, the Dungeness crab, is a commercially important species on the Pacific Northwest coast as the most profitable fishery in Oregon and an important ecological player as both predator and prey. Understanding the spatial distribution of Dungeness throughout different life history stages is beneficial both ecologically and economically. Zostera japonica is an established invasive species of seagrass in the Pacific Northwest and may also be important habitat for recently settled juvenile Dungeness. We examined the distribution of juvenile Dungeness in May 2013 among Z. japonica, Z. marina, and open habitats in the Yaquina Bay Estuary in Newport, Oregon. We correlated Dungeness abundance with habitat, shoot density and biomass of seagrass, tidal height, and abundance of Hemigrapsus oregonensis, another local species of crab. Our results indicate that Dungeness preferred seagrass habitats to open mud, but had no apparent preference among different species of seagrasses, despite the correlation of Dungeness abundance with seagrass biomass. This study increases scientific understanding of the life cycle of Dungeness crabs and the importance of estuarine habitats, which must be protected in order to achieve a sustainable fishery. Title: Comparing Metacarcinus magister settlement preferences among the seagrasses Zostera marina and Zostera japonica Author: Heidmann, Sarah, Jaco, Erin Metacarcinus magister, the Dungeness crab, is a commercially important species on the Pacific Northwest coast as the most profitable fishery in Oregon and an important ecological player as both predator and prey. Understanding the spatial distribution of Dungeness throughout different life history stages is beneficial both ecologically and economically. Zostera japonica is an established invasive species of seagrass in the Pacific Northwest and may also be important habitat for recently settled juvenile Dungeness. We examined the distribution of juvenile Dungeness in May 2013 among Z. japonica, Z. marina, and open habitats in the Yaquina Bay Estuary in Newport, Oregon. We correlated Dungeness abundance with habitat, shoot density and biomass of seagrass, tidal height, and abundance of Hemigrapsus oregonensis, another local species of crab. Our results indicate that Dungeness preferred seagrass habitats to open mud, but had no apparent preference among different species of seagrasses, despite the correlation of Dungeness abundance with seagrass biomass. This study increases scientific understanding of the life cycle of Dungeness crabs and the importance of estuarine habitats, which must be protected in order to achieve a sustainable fishery. Close

• 3. [Article] Dungeness Settlement Paper.docx

  Citation × Citation Citation Abstract Copy Title: Dungeness Settlement Paper.docx Author: Heidmann, Sarah, Jaco, Erin Title: Dungeness Settlement Paper.docx Author: Heidmann, Sarah, Jaco, Erin Close

• 4. [Article] Dungeness Settlement Paper.pdf

  Citation × Citation Citation Abstract Copy Title: Dungeness Settlement Paper.pdf Author: Heidmann, Sarah, Jaco, Erin Title: Dungeness Settlement Paper.pdf Author: Heidmann, Sarah, Jaco, Erin Close