BPA Fish and Wildlife FY 1998 Proposal
Section 1. Summary
Section 2. Goals
Section 3. Background
Section 4. Purpose and methods
Section 5. Planned activities
Section 6. Outcomes, monitoring and evaluation
Section 7. Relationships
Section 8. Costs and FTE
see CBFWA and BPA funding recommendations
Title of project
Avian Predation On Juvenile Salmonids in the Lower Columbia River
BPA project number 9702400
Estimate the numbers of juvenile salmonids consumed by colonial waterbirds (i.e., double-crested cormorant, Caspian tern, California gull, ring-billed gull, glaucous-winged gull) in the lower Columbia River, identify conditions and locales where avian predation is most prevalent, provide recommendations to reduce predation by fish-eating birds, and evaluate the efficacy of control measures that are implemented.
Business name of agency, institution or organization requesting funding
Oregon State University/Columbia River Inter-Tribal Fish Commission
Proposal contact person or principal investigator
Supports a healthy Columbia basin; maintains biological diversity; increases run sizes or populations; adaptive management (research or M&E)
|Target stock||Life stage||Mgmt code (see below)|
|All salmonid stocks consumed by piscivorous waterbirds||Juvenile||(P), (L), W|
|All salmonid stocks consumed by piscivorous waterbirds||Juvenile||(P), (L), W|
|Affected stock||Benefit or detriment|
|Other fish consumed by piscivorous waterbirds||Either|
Stream area affected
Stream name Lower Columbia River
Stream miles affected 340 (9 colonies will be studied on the lower Columbia River from the estuary to Richland, WA)
Hydro project The results from this study could be used to mitigate damages caused by birds at all lower Columbia River dams.
The CRITFC received funding ($20,589) from the Columbia Basin PIT-Tag Information System Project (BPA-9008000) to recover PIT tags from piscivorous waterbird breeding colonies. All recovered tag codes were provided to PSMFC and entered into the PITAGIS database. In 1996, BPA directly funded a photo census of all piscivorous waterbird breeding colonies in our study area. That census produced a set of high resolution photos which were then analyzed to estimate the breeding population size at each colony.
Biological results achieved
Systematic sampling for PIT tags placed in juvenile salmonids was carried out at Rice Island — located in the Columbia River estuary — in 1996. These results indicate that more than 15,000 PIT tags have been deposited by terns nesting on the island, suggesting that these birds have consumed large numbers — probably millions — of tagged and untagged smolts over the years. Plans are currently underway to sample for PIT tags at a piscivorous waterbird colony on the Columbia River near the Snake River confluence. The photo census conducted in 1996 has identified the location of all large colonies of fish-eating birds on the lower Columbia River. Analysis of the photos provided estimates of the breeding population size at each colony. When compared to historical data, these results suggest that (1) the number of breeding colonies of some piscivorous waterbirds has increased and (2) most, if not all, of these breeding colonies appear to be growing.
Project reports and papers
Data obtained from our PIT tag recovery study has been included in the PITAGIS database. We are currently working on a draft report that summarizes our results, to include an estimate of the total number of PIT tags at the Caspian tern colony at Rice Island. We will use these data to address questions concerning avian predation rates on juvenile salmonids and how these rates may vary by salmonid species and size, migration year, passage conditions, colony location, and avian predator species. We will report the results of the photo census conducted in 1996 in a future report submitted as part of this contract (BPA-5505900).
Adaptive management implications
Past work will allow more time to be spent in implementation, rather than planning, in the first year of this project. We have identified the study populations, estimated their size, established the methods to be used in censusing piscivorous waterbirds, and developed the techniques to be used in sampling for PIT tags on piscivorous waterbird breeding colonies. finally, we have established important contacts with agency personnel critical to the success of a project of this scope.
Specific measureable objectives
We will build a bioenergetics model to estimate predation by colonial waterbirds on juvenile salmonids in the lower Columbia River. Specifically, we will: (1) identify the location, size, and population trajectories of piscivorous waterbird breeding colonies, (2) investigate breeding chronology and productivity of piscivorous waterbird colonies, (3) determine diet composition of fish-eating birds, including taxonomic composition and energy content of various prey types, (4) estimate forage fish consumption rates, with special emphasis on juvenile salmonids, by breeding adults and their young, (5) identify foraging range, foraging strategies, and habitat utilization by piscivorous waterbirds, (6) recover salmon PIT tags from piscivorous waterbird colonies, and (7) compile information regarding potential mitigation techniques.
It is not certain whether avian predation is a significant source of mortality for juvenile salmonids. Furthermore, if avian predation is determined to be significant, we do not know if there are practical management activities to address the problem.
Available data suggest that predation is a major source of mortality for juvenile salmonids migrating through the mainstem Columbia and Snake rivers. Anthropogenic perturbations to the Columbia River System have exacerbated predation-related mortality and contributed to increases in populations of some predators. Piscivorous waterbird populations have increased dramatically with expanding agricultural development and the expansion of available breeding habitat in the Columbia River Basin. New islands created by dredging and impounding the Columbia River have provided safe nest sites and attracted gulls and other colonial waterbirds to breed. The breeding season of these piscivorous birds coincides with the period of out-migration of salmon smolts, potentially resulting in intense predation pressure in the vicinity of larger colonies. The chick-rearing period is the stage of the annual cycle when population energy requirements are greatest due to intense foraging activity by breeding adults and rapid growth in nestlings
Current management practices on the Columbia and Snake rivers offer many opportunities for predators to exploit salmon as a food source. Hydroelectric dams create "bottlenecks" to salmon migration and often injure or disorient out-migrating juvenile salmonids, increasing their vulnerability to avian predators. Hatchery and juvenile transportation practices that release salmonids in mass offer avian predators additional opportunities to exploit concentrated and vulnerable prey. While extensive research has been conducted on the effects of piscivorous fishes on the survival of salmonids in the mainstem Columbia and Snake rivers, no comprehensive study of avian predation on juvenile salmonids has been undertaken
Control measures have been implemented to protect out-migrating juvenile salmonids from avian predators at most dams. Some hatcheries are experimenting with different release strategies to reduce avian predation on hatchery-reared juvenile salmonids. Although there is evidence that some of these measures may be effective, both the extent of predation-related mortality and the efficacy of control measures is largely unknown.
Hypothesis to be tested
The testable hypotheses of this study are: (1) the magnitude of avian predation poses a significant threat to the survival of salmonids in general, and threatened and endangered snake River salmon specifically; (2) the majority of salmonid losses to avian predators occurs near breeding colonies of colonial-nesting species and at sites where smolts are concentrated at or near the water surface (e.g., dams); (3) avian predator populations are growing as a result of anthropogenic factors; and (4) expanded or new management practices directed at avian predators can significantly reduce current levels of predation by fish-eating birds.
No alternative approaches have been proposed.
Justification for planning
The primary objectives of this research are to (1) determine whether or not piscivorous waterbirds pose a significant threat to the survival of juvenile salmonids and (2) identify conditions and locales where avian predation is most prevalent. If avian predation is determined to be a major source of mortality for juvenile salmonids in general, and threatened or endangered stocks specifically, we will develop recommendations to reduce predation by fish-eating birds and evaluate the efficacy of control measures that are implemented. This research will be important in (1) the prioritization of salmon restoration projects vying for limited funds, (2) the implementation of appropriate measures to reduce predation by fish-eating birds, and (3) the justification for mitigation measures that might not be popular with some segments of the population. As part of our work, we will coordinate all activities with the appropriate agencies and tribes.
We will build a bioenergetics model to estimate the number of juvenile salmonids consumed by piscivorous waterbirds in the lower Columbia River. In building the model, we will (1) use aerial photos taken during late incubation to estimate the breeding population size of large piscivorous waterbird colonies, (2) collect diet samples from adults and their young using both lethal and non-lethal methods to determine the species composition and energy content of the diet, (3) use the doubly-labeled water technique to directly measure field metabolic rates of breeding adults during the chick rearing period, (4) use the time-activity budget method to measure field metabolic rates of breeding adults outside the chick rearing period, (5) use allometric equations from the published literature to estimate the energy requirements of young, (6) conduct ground surveys to determine the breeding chronology and productivity of piscivorous waterbirds, and (7) measure the parental provisioning rates and the growth rates of nestlings. In addition, we will (1) use transect sampling and radio telemetry methods to identify the foraging range, foraging strategies, and habitat utilization by piscivorous waterbirds, (2) use soil sieves, electronic PIT tag readers, and visual searches to recover salmon PIT tags from piscivorous waterbird colonies to address questions concerning predation rates on juvenile salmonids and how these rates may vary by salmonid species and size, migration year, passage conditions, colony location, and avian predator species, (3) compile information from the published literature and agency sources regarding potential mitigation techniques.
|Phase Planning||Start Jan. 1996||End Dec. 2000||Subcontractor CRITFC, see above for specific responsibilities|
|The agency responsible and date of completion are noted in parentheses following each task. 1. Identify the breeding colonies of piscivorous waterbirds to be included in the study (OSU & CRITFC: June, 1996 and ongoing as needed). 2. Develop research methods (OSU & CRITFC: ongoing as needed). 3. Coordinate all activities with the appropriate agencies and tribes (OSU & CRITFC: ongoing as needed). 4. Obtain the necessary permits (OSU & CRITFC: ongoing as needed). 5. Hire necessary personnel and acquire equipment (OSU & CRITFC: ongoing as needed).|
|Phase Implementation||Start June, 1996||End Dec, 2001||Subcontractor CRITFC, see above for specific responsibilities|
|The agency responsible and date of completion are noted in parentheses following each task. In general, colonies in the Columbia River estuary will be studied in 1997 (i.e., Caspian terns) and 1998 (i.e., double-crested cormorants and glaucous-winged gulls), and colonies above Bonneville Dam will be studied in 1999 and 2000 (i.e., California and ring-billed gulls). Each year, censuses will be conducted at all colonies and diet studies will be conducted at representative colonies in the estuary and above Bonneville dam. 1. Conduct aerial photo census to locate and estimate the size of piscivorous waterbird colonies (CRITFC: June, 1996-2000). 2. Conduct search of existing literature and agency files to obtain information on past distribution and size of piscivorous waterbird colonies in the Columbia River Basin (CRITFC: ongoing as needed). 3. Determine clutch size, hatching success, nestling survival, and overall nesting success (CRITFC: July, 1997-2000). 4. Determine growth rates of chicks (OSU: July, 1997-2000). 5. Measure nesting chronology of piscivorous waterbird colonies (CRITFC: July, 1997-2000). 6. Collect and analyze diet samples from breeding adults and nestlings to determine seasonal taxonomic composition of the diet and energy content of various prey types (OSU & CRITFC: October, 1997-2000). 7. Measure parental provisioning rates of food energy to young (OSU: July, 1997-2000). 8. Measure adult daily energy expenditure throughout the nesting season using the doubly labeled water and time-activity budget methods (OSU: July, 1997-2000). 9. Measure energy requirements of young over the entire nestling period (OSU: July, 1997-2000). 10. Conduct analysis to determine daily energy expenditure (OSU: November, 1997-2000) 11. Conduct periodic systematic sampling along transects to identify foraging concentrations of piscivorous waterbirds (OSU: July, 1997-2000). 12. Use radio telemetry methods to investigate foraging ecology of piscivorous waterbirds and evaluate the efficacy of management actions implemented to reduce avian predation (OSU: July, 1998-2000) 13. Use soil sieves, electronic PIT tag readers, and visual searches to recover salmon PIT tags from piscivorous waterbird colonies (CRITFC: September, 1996-2000). 14. Conduct a computerized literature search on methods of avian damage control (CRITFC: ongoing as needed). 15. Compile all available information to develop a set of recommendations to reduce avian predation on juvenile salmonids in the lower Columbia River (OSU & CRITFC: ongoing as needed).|
Constraints or factors that may cause schedule or budget changes
Constraints include: (1) permission to access restricted areas where fish-eating birds forage (e.g., mainstem hydroelectric dams) and nest; and (2) availability of permits for the collection of birds for diet analysis and the gathering of other pertinent biological information.
SUMMARY OF EXPECTED OUTCOMES
Expected performance of target population or quality change in land area affected
We expect that under certain circumstances avian predation on salmonids will be a significant source of mortality. We will identify the important factors contributing to high avian predation rates on juvenile salmonids, and use that information to develop and test practical management alternatives to reduce predation-related mortality.
Present utilization and convservation potential of target population or area
Columbia River salmon and steelhead are an important economic, cultural, and spiritual resource to the people of the Pacific Northwest. Currently, salmon runs are not sufficient to support these needs and many stocks have been listed as threatened or endangered under the Endangered Species Act. This project will gather information that should be important in developing plans for the recovery of this important resource.
Assumed historic status of utilization and conservation potential
Historically, salmon and steelhead returning to the Columbia River Basin supported the economic, cultural, and spiritual needs of the people of the Pacific Northwest.
Long term expected utilization and conservation potential for target population or habitat
Restoration of salmonid stocks so that subsistence, commercial, and sport harvest can continue without jeopardizing the future conservation of the resource.
Contribution toward long-term goal
Results from this study will improve our understanding of the factors affecting salmonid survival in the Columbia River Basin and provide managers with information that should prove important in decisions regarding salmon recovery.
Indirect biological or environmental changes
If avian predation is determined to be a significant source of mortality for juvenile salmonids, mitigation measures might be implemented to reduce predation by fish-eating birds. These measures will likely cause changes in the distribution and/or number of breeding piscivorous waterbirds in the lower Columbia River by direct control or alterations of suitable breeding habitat for important predator populations (e.g., dredge spoil islands).
Environmental attributes affected by the project
Changes assumed or expected for affected environmental attributes
This project will not directly produce any near or long term changes to environmental attributes. Results from this project could be used to develop plans to reduce avian predation of juvenile salmonids, thereby, all else being equal, increasing the number of adult salmonids returning to the basin. Furthermore, the mitigation measures implemented may cause changes in the distribution and/or number of breeding piscivorous waterbirds by direct control or alterations to suitable breeding habitat of important predator populations.
Measure of attribute changes
Assessment of effects on project outcomes of critical uncertainty
If avian predation is found not to be a significant factor in the survival of salmonids, no mitigation will be recommended or proposed. If avian predation is an important factor in the survival of juvenile salmonids, then we will assess the feasibility of potential mitigation measures.
This project is designed to assess the impacts of avian predation on survival of juvenile salmonids in general, and threatened and endangered snake River salmon specifically, in the lower Columbia River. We will use bioenergetics modelling to estimate the number of juvenile salmonids eaten by avian predators in the lower Columbia River from the estuary to the head of McNary Pool, identify conditions under which predation is most prevalent, determine predator population trajectories, and provide recommendations to reduce predation by fish-eating birds. These results will improve our understanding of the factors affecting salmonid survival in the Columbia River Basin and provide managers with information that should prove important in decisions regarding salmon recovery.
This project will be coordinated with agencies and tribes involved in both fish and wildlife management. Information gathered as part of our research will be combined with data from agency sources to define and address the problem. Regional fish and wildlife managers will work together to evaluate and implement a plan that promotes a balance between the needs of fish and wildlife.
Provisions to monitor population status or habitat quality
As part of this project, we will monitor the population status of all large piscivorous waterbird colonies over the term of the research. Other agencies or organizations (e.g., NMFS, FPC) monitor the status of juvenile salmonids.
Data analysis and evaluation
Results from this research will be published in peer review scientific jourls. This will assure that the data analysis and interpretation of results meet rigorous standards in this field of research.
Information feed back to management decisions
The results from this study will be made available to the appropriate fish and wildlife managers so that decisions can be made regarding management of piscivorous waterbirds to increase survival of juvenile salmonids. We will make recommendations as to which measures make sense from an ecological perspective and it will be up to the resource management agencies to implement whatever mitigative measures are deemed appropriate.
Critical uncertainties affecting project's outcomes
A multi-year study will preclude management decisions being made based on anomalous results (e.g., due to extreme weather that negatively affects predator and/or prey populations) from a single year.
Incorporating new information regarding uncertainties
We will use an adaptive management approach in conducting this research so that unforeseen circumstances can be accommodated in the research design.
Increasing public awareness of F&W activities
The results from this research will be made available to the public through annual reports, a final completion report, and publications in peer reviewed scientific literature. In addition, the interim results of this research will be presented at meetings of professiol societies at the state, regional, and national levels.
|Related BPA project||Relationship|
|9008000 Columbia Basin Pit-tag Information System||As part of our work, we will recover salmon PIT tags from piscivorous waterbird colonies. We will provide all interrogations of PIT tag codes to PSMFC to be included in the PITAGIS database.|
|5503800 1997-98 Eval. of Juvenile Fall Chinook Stranding on the Hanford Reach||We will collaborate with WDFW in their investigations of stranding effects on the Hanford Reach, specifically the impacts of piscivorous waterbirds on the survival of stranded juvenile fall chinook.|
|Related non-BPA project||Relationship|
|Behavior and fate of juvenile salmonids entering the tailwaters of The Dalles Dam via spill /USACE||Avian predation is one source of upriver mortality for radio-tagged smolts used in this study. We will work cooperatively with these agencies to collect radio tags deposited on the breeding colonies of piscivorous waterbirds. Also, we will incorporate information from their study with our work to build a comprehensive understanding of avian predation on juvenile salmonids in the lower Columbia River.|
|Evaluation of facilities for collection, bypass, and transportation of outmigrating chinook salmon/USACE||Avian predation is one source of estuary mortality for radio-tagged smolts used in this study. We will work cooperatively with these agencies to collect radio tags deposited on the breeding colonies of piscivorous waterbirds. Also, we will incorporate information from their study with our work to build a comprehensive understanding of avian predation on juvenile salmonids in the Columbia River estuary.|
|Predation by birds and effectiveness of predation control measures at Bonneville, The Dalles, and John Day dams/USACE & ADC||Avian predation abatement measures are implemented and their effectiveness evaluated at these lower Columbia River dams. As part of this program, some birds that forage near dams are shot. We will work with these agencies to collect these birds for the purpose of determining diet composition. Also, we will incorporate information from their study with our work to build a more comprehensive understanding of avian predation on juvenile salmonids in the lower Columbia River.|
Opportunities for cooperation
This project will be conducted cooperatively by the Oregon Cooperative Wildlife Research Unit at Oregon State University and the Columbia River Inter-tribal Fish Commission. Additional cooperators for work on colonial waterbirds in the Columbia River estuary include the U.S. Fish and Wildlife Service (POC: Al Clark, Refuge Biologist), and the Oregon Cooperative Fishery Research Unit (POC: Larry Davis and Carl Schreck). For work farther up-river, cooperators include the U.S. Fish and Wildlife Service (POC: Eric Nelson, Refuge Biologist), U.S. Army Corps of Engineers (POC: Robert Stansell, Gretchen Starke, and other Corps biologists), and the Oregon Cooperative Fishery Research Unit (POC: John Snelling and Carl Schreck). Animal Damage Control (ADC) has been charged with implementing avian predation abatement measures at lower Columbia River Dams. We will work with ADC and the Corps to collect birds shot as part of this program for the purpose of determining diet of adult birds outside the chick rearing period. Additionally, we will collaborate with the Washington Department of Fish and Wildlife (WDFW) in their study that investigates the effects of stranding on juvenile fall chinook in the Hanford Reach. We anticipate that additional collaborative and cooperative arrangements will be forged with other refuge managers and agencies currently engaged in or planning work on piscivorous birds on the Columbia River. Following the first field season, we will organize and conduct a workshop for agency personnel to exchange information, identify additional data sources, forge stronger collaborative ties, and evaluate potential mitigation actions concerning avian predation on juvenile salmonids.
|Future funding needs||Past obligations (incl. 1997 if done)|
|FY||Other funding source||Amount||In-kind value|
Other non-financial supporters
The U.S. Fish and Wildlife Service (POC: Al Clark, Eric Nelsen, and others); Columbia River Research Laboratory, USGS/BRD (POC: Tom Poe); Oregon Cooperative Fishery Research Unit, OSU (POC: Carl Schreck, Larry Davis, and John Snelling); U.S. Army Corps of Engineers (POC: Rosy Masaika, Robert Stansell, Gretchen Starke, and others); USDA/Animal Damage Control (POC: Tom Halstead, John Cummings, and others); Washington Dept. Fish and Wildlife (POC:Paul Wagner and others); Oregon Dept. of Fish and Wildlife (POC: Bruce Schmidt and others); Yakama Indian Nation (POC: Lynn Hatcher); Confederated Tribes of the Umatilla Indian Reservation (POC: Gary James); Confederated Tribes of the Warm Springs Reservation of Oregon (POC:Jody Calica); Nez Perce Tribe (POC:Silas Whitman); and other agencies have pledged their cooperation and support for this work.
How does percentage apply to direct costs
OSU:These overhead rates apply to modified direct project costs (i.e., no overhead is charged on equipment, tuition, or sub-contracts beyond the first $25,000); CRITFC:0% on sub-contracts and non-expendable property