Download or read book Research Monitoring and Evaluation of Avian Predation on Salmonid Smolts in the Lower and Mid Columbia River 2008 Draft Season Summary written by and published by . This book was released on 2009 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes investigations into predation by piscivorous colonial waterbirds on juvenile salmonids (Oncorhynchus spp.) from throughout the Columbia River basin during 2008. East Sand Island in the Columbia River estuary again supported the largest known breeding colony of Caspian terns (Hydroprogne caspia) in the world (approximately 10,700 breeding pairs) and the largest breeding colony of double-crested cormorants (Phalacrocorax auritus) in western North America (approximately 10,950 breeding pairs). The Caspian tern colony increased from 2007, but not significantly so, while the double-crested cormorant colony experienced a significant decline (20%) from 2007. Average cormorant nesting success in 2008, however, was down only slightly from 2007, suggesting that food supply during the 2008 nesting season was not the principal cause of the decline in cormorant colony size. Total consumption of juvenile salmonids by East Sand Island Caspian terns in 2008 was approximately 6.7 million smolts (95% c.i. = 5.8-7.5 million). Caspian terns nesting on East Sand Island continued to rely primarily on marine forage fishes as a food supply. Based on smolt PIT tag recoveries on the East Sand Island Caspian tern colony, predation rates were highest on steelhead in 2008; minimum predation rates on steelhead smolts detected passing Bonneville Dam averaged 8.3% for wild smolts and 10.7% for hatchery-raised smolts. In 2007, total smolt consumption by East Sand Island double-crested cormorants was about 9.2 million juvenile salmonids (95% c.i. = 4.4-14.0 million), similar to or greater than that of East Sand Island Caspian terns during that year (5.5 million juvenile salmonids; 95% c.i. = 4.8-6.2 million). The numbers of smolt PIT tags recovered on the cormorant colony in 2008 were roughly proportional to the relative availability of PIT-tagged salmonids released in the Basin, suggesting that cormorant predation on salmonid smolts in the estuary was less selective than tern predation. Cormorant predation rates in excess of 30%, however, were observed for some groups of hatchery-reared fall Chinook salmon released downstream of Bonneville Dam. Implementation of the federal plan 'Caspian Tern Management to Reduce Predation of Juvenile Salmonids in the Columbia River Estuary' was initiated in 2008 with construction by the Corps of Engineers of two alternative colony sites for Caspian terns in interior Oregon: a 1-acre island on Crump Lake in the Warner Valley and a 1-acre island on Fern Ridge Reservoir near Eugene. We deployed Caspian tern social attraction (decoys and sound systems) on these two islands and monitored for Caspian tern nesting. Caspian terns quickly colonized the Crump Lake tern island; about 430 pairs nested there, including 5 terns that had been banded at the East Sand Island colony in the Columbia River estuary, over 500 km to the northwest. No Caspian terns nested at the Fern Ridge tern island in 2008, but up to 9 Caspian terns were recorded roosting on the island after the nesting season. There were two breeding colonies of Caspian terns on the mid-Columbia River in 2008: (1) about 388 pairs nested at the historical colony on Crescent Island in the McNary Pool and (2) about 100 pairs nested at a relatively new colony site on Rock Island in the John Day Pool. Nesting success at the Crescent Island tern colony was only 0.28 young fledged per breeding pair, the lowest nesting success recorded at that colony since monitoring began in 2000, while only three fledglings were raised at the Rock Island tern colony. The diet of Crescent Island Caspian terns consisted of 68% salmonid smolts; total smolt consumption was estimated at 330,000. Since 2004, total smolt consumption by Crescent Island terns has declined by 34%, due mostly to a decline in colony size, while steelhead consumption has increased 10% during this same period. In 2008, approximately 64,000 steelhead smolts were consumed by Caspian terns nesting at Crescent Island. Based on smolt PIT tag recoveries on the Crescent Island Caspian tern colony, the average predation rate on in-river migrants from the Snake River (all species and run types combined based on interrogations at Lower Monumental Dam) was at least 1.4%. Predation rates on PIT-tagged steelhead smolts were greater than those for other salmonid species; 6.0% of wild steelhead smolts from the Snake River were consumed by Crescent Island terns. The double-crested cormorant colony on Foundation Island in the mid-Columbia River consisted of at least 360 pairs nesting in trees in 2008. The proportion of juvenile salmonids in stomach samples collected from cormorants nesting on Foundation Island during the peak of the smolt out-migration was about 45% of prey biomass.

Download or read book Research Monitoring and Evaluation of Avian Predation on Salmonid Smolts in the Lower and Mid Columbia River Final 2012 Annual Report written by Ken Collis and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study continues investigations of predation by piscivorous waterbirds on juvenile salmonids (Oncorhynchus spp.) from throughout the Columbia River Basin.

Download or read book Avian Predation on Juvenile Salmonids in the Columbia River written by Allen Evans and published by . This book was released on 2015 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: "To address concerns over the impact of avian predation on juvenile salmonids in the Columbia River Basin, we evaluated predation probabilities on steelhead, yearling Chinook salmon, and subyearling Chinook salmon by piscivorous birds from 11 different breeding colonies. Salmonid smolts were tagged and released as part of survival studies using the Juvenile Salmonid Acoustic Telemetry System, a network of hydrophones that provided detections of acoustic-tagged fish at various spatial and temporal scales during seaward migration. Fish were released and tracked during passage through a 251 kilometer (km) section of the lower Snake River and lower Columbia River in 2012, a 192 km section of the lower Columbia River in 2014, and a 184 km section of the middle Columbia River during 2014. Detections of tagged smolts at telemetry arrays, coupled with the recovery of tags on nearby bird colonies, were used to quantify where avian predation occurred, when it occurred, and the cumulative impact of predation by colonial waterbirds on the survival of tagged fish. Results were also used to estimate unaccounted for smolt mortality (total smolt mortality - mortality due to colonial waterbirds), which was due in part to factors other than bird predation (e.g., piscine predation, mortality during dam passage, and other non-avian mortality factors)."--From summary.

Download or read book Evaluate the Impacts of Avian Predation on Salmonid Smolts from the Columbia and Snake Rivers 2008 Final Season Summary written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluate the Impacts of Avian Predation on Salmonid Smolts from the Columbia and Snake Rivers 2007 Final Season Summary written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Avian Predation on Juvenile Salmonids in the Lower Columbia River written by United States. Bonneville Power Administration and published by . This book was released on 2001 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Avian Predation on Juvenile Salmonids in the Lower Columbia River Research Project written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Avian Predation in the Columbia Plateau Region Management Monitoring and Evaluation written by Ken Collis and published by . This book was released on 2020 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The primary objectives of this study in 2019 were to: (1) implement and evaluate the Inland Avian Predation Management Plan (IAPMP; USACE 2014), including adaptive management actions, in order to dissuade Caspian terns (Hydroprogne caspia) from nesting on Crescent Island, Goose Island, and elsewhere in Potholes Reservoir to reduce tern predation on Endangered Species Act (ESA)-listed juvenile salmonids (Oncorhynchus spp.); (2) investigate the distribution, colony size, and smolt impacts of unmanaged piscivorous colonial waterbirds (i.e. California gulls [Larus californicus], ring-billed gulls [L. delawarensis], American white pelicans [Pelecanus erythrorhynchos]), and double-crested cormorants [Phalacrocorax auratus] to help identify immerging avian predation issues in the Columbia Plateau region (CPR) that may be of concern to resource managers; and (3) calculate aggregate estimates of avian predation (i.e. consumption by all predator species and colonies combined within a specific river reach) and estimates of reach-specific survival of juvenile salmonids during downstream passage. Collectively, these objectives address several management-relevant questions needed to maximize the benefits to ESA-listed salmonids in managing piscivorous colonial waterbirds, while also maintaining a multiyear avian predation dataset in the Columbia River basin."--Project Objectives (pages 6-7).

Download or read book Evaluation of Effects of Extended Transport on Survival of Salmonid Smolts Impacts of Fish Predation in the Lower Columbia River written by and published by . This book was released on 2009 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Impacts of Avian Predation on Salmonid Smolts from the Columbia and Snake Rivers written by Daniel D. Roby and published by . This book was released on 2011 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Avian Predation on Juvenile Salmonids in the Lower Columbia River written by and published by . This book was released on 2000 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors initiated a field study in 1997 to assess the impacts of fish-eating colonial waterbirds (i.e., terns, cormorants, and gulls) on the survival of juvenile salmonids in the lower Columbia River. Here the authors present results from the 1998 breeding season, the second field season of work on this project. The research objectives in 1998 were to: (1) determine the location, size, nesting chronology, nesting success, and population trajectories of breeding colonies of fish-eating birds in the lower Columbia River; (2) determine diet composition of fish-eating birds, including taxonomic composition and energy content of various prey types; (3) estimate forage fish consumption rates, with special emphasis on juvenile salmonids, by breeding adults and their young; (4) determine the relative vulnerability of different groups of juvenile salmonids to bird predation; (5) identify foraging range, foraging strategies, and habitat utilization by piscivorous waterbirds; and (6) test the feasibility of various alternative methods for managing avian predation on juvenile salmonids and develop recommendations to reduce avian predation, if warranted by the results.

Download or read book Avian Predation on Juvenile Salmonids in the Lower Columbia River written by and published by . This book was released on 1998 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors initiated a field study in 1997 to assess the impacts of fish-eating colonial waterbirds (i.e., terns, cormorants, and gulls) on the survival of juvenile salmonids in the lower Columbia River. Here the authors present results from the 1998 breeding season, the second field season of work on this project. The research objectives in 1998 were to: (1) determine the location, size, nesting chronology, nesting success, and population trajectories of breeding colonies of fish-eating birds in the lower Columbia River; (2) determine diet composition of fish-eating birds, including taxonomic composition and energy content of various prey types; (3) estimate forage fish consumption rates, with special emphasis on juvenile salmonids, by breeding adults and their young; (4) determine the relative vulnerabilit2048 different groups of juvenile salmonids to bird predation; (5) identify foraging range, foraging strategies, and habitat utilization by piscivorous waterbirds; and (6) test the feasibility of various alternative methods for managing avian predation on juvenile salmonids and develop recommendations to reduce avian predation, if warranted by the results.

Download or read book Avian Predation on Juvenile Salmonids in the Lower Columbia River written by Ken Collis and published by . This book was released on 2000 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of an Index to Bird Predation of Juvenile Salmonids Within the Yakima River 2001 Annual Report written by and published by . This book was released on 2002 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Avian predation of fish is suspected to contribute to the loss of out-migrating juvenile salmonids in the Yakima Basin, potentially constraining natural and artificial production. In 1997 and 1998, the Yakima/ Klickitat Fisheries Project (YKFP)--whose goal is increasing natural production within the Yakima River--initiated investigations to assess the feasibility of developing an index to avian predation of juvenile salmon within the river. This research confirmed that Ring-billed Gulls and Common Mergansers were the primary avian predators of juvenile salmon (Phinney et al. 1998), and that under certain conditions could significantly impact migrating smolt populations. Beginning in 1999, the Washington Cooperative Fish and Wildlife Research Unit (WACFWRU) was asked by the YKFP to continue development of avian consumption indices. Monitoring methods developed by Phinney et al. (1998) were adopted (with modifications) and monitoring of impacts to juvenile salmon along river reaches and at areas of high predator/prey concentrations (colloquially referred to as ''hotspots'') has continued each year through 2001. In 2001, piscivorous birds were counted from river banks at hotspots and from a raft or drift boat along river reaches. Consumption by gulls at hotspots was based on direct observations of foraging success and modeled abundance; consumption by all other piscivorous birds was estimated using published dietary requirements and modeled abundance. Seasonal patterns of avian piscivore abundance were identified, diurnal patterns of gull abundance at hotspots were identified, and predation indices were calculated for hotspots and river reaches (for both spring and summer). Changes in survey methods in 2001 included the addition of surveys in the ''Canyon'' reach during spring and altering the method of directly measuring gull feeding rates at hotspots. Primary avian predators in 2001 were ''gulls'' (California and Ring-billed) at hotspots and Common Mergansers within upper river reaches. Consumption on the lower reaches was distributed among a number of species, with slightly more then half of all fish consumption being attributed to American White Pelicans. Estimated consumption by gulls at both hotspots combined (8 Apr-30 Jun) was 169,883 fish. Assuming a worst case scenario (all fish taken were smolts) this represented approximately 4.9% of all smolts estimated passing or being released from the Prosser Dam area during the 2001 smolt migration season. Total gull abundances and estimates of consumption between the two hotspot sites were opposite that seen in 2000. Foraging gulls at Horn Rapids Dam were regressed against flow for the 3 years and found to be significant (alpha = 0.1, P=0.081, r2 = .2589). A similar 3-year regression vs fish passage through the Chandler Juvenile Fish Facility, however, did not show a significant relationship (alpha = 0.1, P = 0.396, r2 = .3708). Total estimated take by Common Mergansers across all strata surveyed was 14,777 kg between 8 Apr and 31 Aug, 2001. Approximately 66 percent of that consumption was within the upper river reaches (Stratum 1) where there is a known breeding population of mergansers. Graphical comparisons of merganser abundances over the three years (1999-2001) in the upper reaches of the Yakima River suggest an increase in 2001 from the previous 2 years in both the spring and summer survey periods, but overlapping confidence intervals prevent assumptions regarding upward or downward trends in abundance.

Download or read book Review written by Range D. Bayer and published by . This book was released on 2003-01-01 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monitoring and Evaluation of Smolt Migration in the Columbia Basin written by and published by . This book was released on 2008 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Program RealTime provided monitoring and forecasting of the 2007 inseason outmigrations via the internet for 26 PIT-tagged stocks of wild ESU Chinook salmon and steelhead to Lower Granite and/or McNary dams, one PIT-tagged hatchery-reared ESU of sockeye salmon to Lower Granite Dam, one PIT-tagged wild stock of sockeye salmon to McNary Dam, and 20 passage-indexed runs-at-large, five each to Rock Island, McNary, John Day, and Bonneville dams. Nineteen stocks are of wild yearling Chinook salmon which were captured, PIT-tagged, and released at sites above Lower Granite Dam in 2007 and have at least one year's historical migration data previous to the 2007 migration. These stocks originate in 19 tributaries of the Salmon, Grande Ronde and Clearwater Rivers, all tributaries to the Snake River, and are subsequently detected through tag identification and monitored at Lower Granite Dam. Seven wild PIT-tagged runs-at-large of Snake or Upper Columbia River ESU salmon and steelhead were monitored at McNary Dam. Three wild PIT-tagged runs-at-large were monitored at Lower Granite Dam, consisting of the yearling and subyearling Chinook salmon and the steelhead runs. The hatchery-reared PIT-tagged sockeye salmon stock from Redfish Lake was monitored outmigrating through Lower Granite Dam. Passage-indexed stocks (stocks monitored by FPC passage indices) included combined wild and hatchery runs-at-large of subyearling and yearling Chinook, coho, and sockeye salmon, and steelhead forecasted to Rock Island, McNary, John Day, and Bonneville dams.

Download or read book Monitoring and Evaluation of Smolt Migration in the Columbia River Basin written by Caitlin Burgess and published by . This book was released on 2000 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Program RealTime provided tracking and forecasting of the 1999 inseason outmigration via the internet for stocks of wild PIT-tagged spring/summer chinook salmon. These stocks were ESUs from sixteen release sites above Lower Granite dam, including Bear Valley Creek, Big Creek, Cape Horn Creek, Catherine Creek, Elk Creek, Herd Creek, Imnaha River, Lake Creek, Loon Creek, Lostine River, Marsh Creek, Minam River, South Fork Salmon River, and Secesh River, Sulfur Creek and Valley Creek. Forecasts were also provided for a stock of hatchery-reared PIT-tagged summer-run sockeye salmon from Redfish Lake and for the runs-at-large of Snake River wild yearling chinook salmon, and steelhead trout. The 1999 RealTime project began making forecasts for a new stock of PIT-tagged wild fall subyearling chinook salmon, as a substitute for forecasts of the wild run-at-large, discontinued June 6. Forecasts for the run-at-large were discontinued when a large release of unmarked hatchery fish into the Snake River made identification of wild fish impossible. The 1999 Program RealTime performance was comparable to its performance in previous years with respect to the run-at-large of yearling chinook salmon (whole season MAD=3.7%), and the run of hatchery-reared Redfish Lake sockeye salmon (whole season MAD=6.7%). Season-wide performance of program RealTime predictions for wild Snake River yearling chinook salmon ESUs improved in 1999, with mean MADs from the first half of the outmigrations down from 15.1% in 1998 to 4.5% in 1999. RealTime performance was somewhat worse for the run-at-large of steelhead trout in 1999, compared to 1998, particularly during the last half of the outmigration when the MAD increased from 2.7% in 1998 to 6.1% in 1999. A pattern of over-predictions was observed in half of the yearling chinook salmon ESUs and the steelhead run-at-large during the month of May. Lower-than-average outflows were observed at Lower Granite dam during the first half of May, the only period of low flows in an year with otherwise higher-than-average-flows. The passage distribution of the stock new to the RealTime forecasting project, the PIT tagged stock of fall subyearling chinook salmon, was predicted with very good accuracy (whole season MAD=4.7%), particularly during the last half of the outmigration (MAD=3.6%). The RealTime project reverted to a pre-1998 method of adjusting PIT-tagged smolt counts at Lower Granite Dam because of its superior performance during the last half of the outmigration.