Great Horned Owl Exposure to Chlorinated Organics at the Kalamazoo River Superfund Site Strause, K.D., Zwiernik, M.J., Park, C.S., Moseley, P., Im, S.H., Blankenship, A.L., Bradley, P.W., Kannan, K., Neigh, A., Pastva, S.D., Giesy, J.P.
Baseline Ecological Risk Assessment for the Kalamazoo River Superfund Site GHO Issues Great Horned Owl identified as receptor of concern for terrestrial food chain Modeled exposure to Kalamazoo River floodplain soils NOAEC HQ= 0.4 Dec 99 Historical tissue samples containing elevated levels of contaminants
Goals Great Horned Owl Study Overview Site Specific Measurement Endpoints for Risk Characterization Bottom-up methodology = Daily dietary PCB dose mg/kg/day Top-down methodology = Mean PCB concentrations in receptor target tissues
Study Scope Study Duration A 4-year study of Chemical Exposure and Productivity 2000; 2001; 2002; 2003 Data Collection Field Seasons Nest Locations 70 mile stretch of River 41 nest platforms and 5 natural nests Zone 3 K/SCM 2 Platforms 2 Natural Zone 3 Downstream 7 Platforms Zone 2 12 Platform 2 Natural Zone 1 12 Platforms Zone 3 Upstream 8 Platforms 1 Natural
Great Horned Owl Study Overview Methodology Bottom up exposure assessment Collect prey remains and regurgitated pellets to identify site specific dietary composition Collect and analyze identified dietary items for PCBs Top down exposure assessment Analyze nestling blood plasma for PCBs Analyze fresh and addled eggs for PCBs Quantify site abundance Survey resident owl populations in KRAOC and background site Quantify site productivity Confirm successful fledglings at each active nest
Great Horned Owl Study Overview Nesting Platforms
Great Horned Owl Study Methodology: Dietary Composition Regurgitated pellets Base of nest tree Associated feeding perch Prey remains Within nest Base of nest tree
Great Horned Owl Dietary Composition Fort Custer Dietary Composition Pellet and Prey Remains Analysis n=35 Trowbridge Dietary Composition Pellet and Prey Remains Analysis n=102 Muskrat 6% Shrew 3% Passerine 5% Waterfowl 6% Muskrat 12% Shrew 3% Passerine 33% Small Mammal 80% Small Mammal 48% Waterfowl 4%
Great Horned Owl Dietary PCB Exposure PCB (mg/kg, ww) 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 Passerines Waterfowl Small Mammals Muskrat Shrew GH Owl Diet Fort Custer Trowbridge
Kalamazoo River Great Horned Owl PCB Dose Dietary PCB Intake Fort Custer Mean = 0.0090 mg/kg/day 95% UCL = 0.0187 mg/kg/day Trowbridge Mean = 0.0547 mg/kg/day 95% UCL = 0.0841 mg/kg/day TRV *NOAEL = 0.41 mg/kg/day LOAEL = 1.23 mg/kg/day *Mclane, R., Anne, M., L. Hughes, L. 1980. Reproductive Success of Screech Owls Fed Aroclor 1248. Arch Environ. Contam. Toxicol. 9:661-665
Kalamazoo River Great Horned Owl Site Specific Dietary HQs 0.25 Hazard Quotient 0.2 0.15 0.1 0.05 0 FC NOAEL FC LOAEL TB NOAEL TB LOAEL
Tissue Collections Plasma/Addled Eggs/ Fresh Eggs Zone 1(Fort Custer): Plasma Addled eggs Zone 2 (Trowbridge impoundment) Plasma Addled eggs Zone 3 (upstream): Fresh eggs Plasma (contingent upon renesting) Zone 3 (downstream): Fresh eggs Plasma (contingent upon renesting)
2000/2002 Owl Tissue Samples Study Site/Region Nestling Plasma Fresh & Addled Eggs Background Sites Zone 3 Upstream (Ceresco) Zone 1 Ft. Custer Exposed Sites Zone 2 Trowbridge Zone 3 Downstream (Menasha) Zone 3 Swan Creek/ Koopman s Marsh 1 1 6 2 2 3 0 1 0 10
Plasma PCB Concentrations Nest Location Background Sites (n=2) Trowbridge/Menasha (n=8) Swan Creek/ Koopman s Marsh (n=2) Blood Plasma PCBs (µg/kg, ww) 7.9 15.1 18.1 82.5 106 198 Mean Blood PCBs (µg/kg, ww) 11.5 ± 5.1 49.5 ± 22.4 152 ± 65.1
PCB (mg/kg, ww)) 25 20 15 10 Owl Egg PCB Concentrations Calculated Measured 5 0 Ceresco/ Ft. Custer n=3 Trowbridge/Menasha n=8 Swan Creek/ Koopman s Marsh n=7
Kalamazoo River Great Horned Owl Egg PCB Concentrations Ft. Custer/Ceresco Mean PCB (mg/kg, ww) 95% UCL PCB (mg/kg, ww) 1.56 2.92 Trowbridge/Menasha Swan Cr./Koopman s TRV 6.60 8.23 12.69 18.77 *NOAEL = 18 mg/kg *Mclane, R., Anne, M., L. Hughes, L. 1980. Reproductive Success of Screech Owls Fed Aroclor 1248. Arch Environ. Contam. Toxicol. 9:661-665
1.5 Kalamazoo River Great Horned Owl Site Specific Egg HQs Hazard Quotient 0.5 1 0 Ft. Custer/ Ceresco Trowbridge/ Menasha Swan Creek/ Koopman s Marsh
Comparison of Risk Assessment Models 0.5 KRAOC 0.5 Fort Custer U95 CL Hazard Quotient 0.4 0.3 0.2 L95 CL Hazard Quotient 0.4 0.3 0.2 U95 CL 0.1 0.1 0 Based on NOAEL L95 CL Based on NOAEL 0
Comparison of Risk Assessment Models 0.5 KRAOC 0.5 Fort Custer U95 CL Hazard Quotient 0.4 0.3 0.2 L95 CL 95% Diet NOAEL Hazard Quotient 0.4 0.3 0.2 U95 CL 0.1 0 Based on NOAEL 0.1 0 95% Diet L95 CL NOAEL Based on NOAEL
Great Horned Owl Abundance Data: Vocalization Surveys (2000-2002) Location Fort Custer n = 25 Trowbridge n = 21 # of GH owls responding per survey # of occupied GH owl breeding territories per survey 1.36 0.2 5.76 0.66
Great Horned Owl Study Productivity: Nest occupancy Fledging success
Total Nestlings Fledged Year 2000 2001 2002 Nestling Fledge/ Active Nest Total Productivity Fort Custer Active Nest - FC04-1/1 1.0 Fledge - 1 - Trowbridge Active Fledge Nest TB13N TB02 TB10 TB02 TB08 TB10 6/6 1.0 1 2 2 1 0 0
Great Horned Owl Study Conclusions Great Horned Owl Hazard Quotients are below expected adverse effect levels Bottom Up/Dietary NOAEL 95% UCL HQ = 0.2 Top Down/Tissue NOAEL 95%UCL HQ= 0.46 Strong Agreement between bottom up and top down exposure assessment methodology Great Horned Owl site-specific dietary composition includes items from aquatic food web Productivity not significantly different between sites Great Horned Owl abundance greater at the study site compared to the background area
Additional Researchers Charlene Cilc Bill Claflin Theresa Grattan Ryan Holem Joe Johnson Paul Jones Denise Kay George Klemolin Scott Kissman Monica MacCarroll Margarete McShane Michelle Moffat Donna Pieracini Dan Villeneuve Acknowledgements Technical Support U.S. Fish and Wildlife Service: Lisa Williams, Dave Best, Charles Mehne MI Dept. of Natural Resources: William Kosmider, Mike Bailey, John Lerg Kellogg Biological Station: Nina Consolotti, Barbara Baker MSU Dept. of Vet Med: Jim Sikarski, Simon Hollemby, Heather Simmons, Kim Cook Kalamazoo Nature Center: Ray Adams Funding: Generously provided Zoology Dept. by & the National Kalamazoo Food Safety River and Toxicology Study Center Group
Wednesday November 20, 2002 P854 Assessing Risks to Resident Great Horned Owls in the Kalamazoo River Floodplain: The Exposure Assessment