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• 381. [Article] 2015 Calapooia River Rapid Bio-Assessments Inventory

  Abstract -- The 2015 Rapid Bio-Assessment inventory of the Calapooia basin covered 37.2 miles of stream habitat. The effort encompassed all of the mainstem and tributary habitats, upstream of the Holley ...

  Citation × Citation Citation Abstract Copy Title: 2015 Calapooia River Rapid Bio-Assessments Inventory Abstract -- The 2015 Rapid Bio-Assessment inventory of the Calapooia basin covered 37.2 miles of stream habitat. The effort encompassed all of the mainstem and tributary habitats, upstream of the Holley Bridge (USGS RM 45.5). Tributary inventories extended to the end of significant rearing potential for anadromous salmonids. In addition, a spring chinook resting count inventory encompassing the same mainstem reach and an additional 9.5 miles downstream to the deconstructed Brownsville Dam site (USGS RM36) was conducted in an attempt to quantify the abundance of adult Spring Chinook returning to the basin to spawn. An inventory of spawning gravel abundance was also conducted in the 30 miles of mainstem and tributary stream habitats exhibiting any anadromous potential (only spawning gravel sites appropriate for steelhead were quantified). Title: 2015 Calapooia River Rapid Bio-Assessments Inventory Abstract -- The 2015 Rapid Bio-Assessment inventory of the Calapooia basin covered 37.2 miles of stream habitat. The effort encompassed all of the mainstem and tributary habitats, upstream of the Holley Bridge (USGS RM 45.5). Tributary inventories extended to the end of significant rearing potential for anadromous salmonids. In addition, a spring chinook resting count inventory encompassing the same mainstem reach and an additional 9.5 miles downstream to the deconstructed Brownsville Dam site (USGS RM36) was conducted in an attempt to quantify the abundance of adult Spring Chinook returning to the basin to spawn. An inventory of spawning gravel abundance was also conducted in the 30 miles of mainstem and tributary stream habitats exhibiting any anadromous potential (only spawning gravel sites appropriate for steelhead were quantified). Close

• 382. [Article] Habitat use and activity patterns of Deacon Rockfish (Sebastes diaconus) at seasonal scales and in response to episodic hypoxia.

  Abstract -- Knowledge of fish movements and residency are key to design and interpretation of results from bioacoustic sonar and visual survey methods, which are being developed as tools for use in nearshore ...

  Citation × Citation Citation Abstract Copy Title: Habitat use and activity patterns of Deacon Rockfish (Sebastes diaconus) at seasonal scales and in response to episodic hypoxia. Abstract -- Knowledge of fish movements and residency are key to design and interpretation of results from bioacoustic sonar and visual survey methods, which are being developed as tools for use in nearshore rocky reef surveys to estimate biomass and species composition. Fishers in Oregon report that an important component of the nearshore catch, Deacon Rockfish (Sebastes diaconus), become unavailable to harvest seasonally, and suggest periodic migration away from nearshore reef areas. Seasonal and spatial variation in landings data potentially support this theory. We used a high-resolution acoustic telemetry array and a combination of presence/absence receiver arrays, to study the daily and seasonal movements and the activity patterns of 11 acoustically tagged Deacon Rockfish on a nearshore rocky reef off Seal Rock, Oregon. Over the 11-month study period, most fish (n=6) exhibited high site fidelity. For the duration of the high-resolution array (5 mo), these fish had small home ranges (mean 95% KDE=4907 m2) and consistent activity patterns, except during seasonal hypoxia (defined as dissolved oxygen concentration [DO] < 2 mg l-1). During the summer months, resident fish were strongly diurnal with high levels of daytime activity above the bottom in relatively rugose habitat, followed by nighttime rest periods in deeper water in habitat of relatively less rugosity. During hypoxia, fish exhibited moderate activity levels with no rest periods and moved well away from their core activity areas on long, erratic forays. Wintertime activity levels were moderate with less defined daily patterns, but fish continued to remain within the array area. We suggest that Deacon Rockfish remain on nearshore reefs throughout the year, but their visual capabilities and prey preferences for seasonally occurring planktonic organisms strongly influences their catchability. Habitat use and activity patterns exhibited by Deacon Rockfish are conducive to bioacoustic sonar and visual survey methods if season, daylight, and oxygen levels are considered. Title: Habitat use and activity patterns of Deacon Rockfish (Sebastes diaconus) at seasonal scales and in response to episodic hypoxia. Abstract -- Knowledge of fish movements and residency are key to design and interpretation of results from bioacoustic sonar and visual survey methods, which are being developed as tools for use in nearshore rocky reef surveys to estimate biomass and species composition. Fishers in Oregon report that an important component of the nearshore catch, Deacon Rockfish (Sebastes diaconus), become unavailable to harvest seasonally, and suggest periodic migration away from nearshore reef areas. Seasonal and spatial variation in landings data potentially support this theory. We used a high-resolution acoustic telemetry array and a combination of presence/absence receiver arrays, to study the daily and seasonal movements and the activity patterns of 11 acoustically tagged Deacon Rockfish on a nearshore rocky reef off Seal Rock, Oregon. Over the 11-month study period, most fish (n=6) exhibited high site fidelity. For the duration of the high-resolution array (5 mo), these fish had small home ranges (mean 95% KDE=4907 m2) and consistent activity patterns, except during seasonal hypoxia (defined as dissolved oxygen concentration [DO] < 2 mg l-1). During the summer months, resident fish were strongly diurnal with high levels of daytime activity above the bottom in relatively rugose habitat, followed by nighttime rest periods in deeper water in habitat of relatively less rugosity. During hypoxia, fish exhibited moderate activity levels with no rest periods and moved well away from their core activity areas on long, erratic forays. Wintertime activity levels were moderate with less defined daily patterns, but fish continued to remain within the array area. We suggest that Deacon Rockfish remain on nearshore reefs throughout the year, but their visual capabilities and prey preferences for seasonally occurring planktonic organisms strongly influences their catchability. Habitat use and activity patterns exhibited by Deacon Rockfish are conducive to bioacoustic sonar and visual survey methods if season, daylight, and oxygen levels are considered. Close