Mink and PCDF/D s in the Tittabawassee River Basin

Transcription

1 Mink and PCDF/D s in the Tittabawassee River Basin Matthew Zwiernik 1 Jeremy Moore 1 Dustin Tazelaar 1 Denise Kay 2 David Hamman 1 Alan Blankenship 2 John P. Giesy 1 1 2

2 Field Studies in Support of a Baseline ERA Dr. Matthew Zwiernik Dr. John Giesy Jeremy Moore Dusty Tazelaar Tim Fredricks Sarah Coefield Rita Seston Mike Fales Lori Williams David Hamman Beth Opperman William Sterling Emily Koppel Melissa Palmer Aquatic Toxicology Laboratory

3 Saginaw Bay Michigan Midland County Midland Tittabawassee River Saginaw County Bay County Saginaw River Shiawassee River Bay City Saginaw

4 Overall Objective Investigate the site-specific relationships between stressors and key receptors. Mink Study Mink population health will likely be an important benchmark Mink often represent worst-case scenario for aquatic ecosystem exposure to dioxins and furans: Feed at the top of the food chain Are sensitive to the effects of F s and D s Defined home range (primarily within river and floodplain)

5 Mink Study Design Site-specific, Multiple-year, Multiple-line of evidence approach Habitat suitability Population health Abundance Morphological measurements» Population demographics (sex, age, weight, length)» Nutritional status» Reproductive history ( female )» Baculum length» Organ and jaw histology Dietary exposure assessment Determine dietary composition Analyze identified dietary items for contaminants Predict exposures Tissue based exposure assessment Quantify contaminants in mink liver Quantify contaminants in mink whole body

6 Habitat Suitability Utilize mink Habitat Suitability Index (HSI) Developed by U.S. Fish and Wildlife Service Field verified for Great Lakes regions Quality of habitat is related to: Carrying capacity Adult survival rate Reproduction Vitality of offspring Seasonal occupancy Cross check (HSI) with distribution and abundance

7 Methods: Habitat Suitability HSI = Habitat conditions at site Optimum habitat conditions To obtain the maximum score of 1.0: 75%+ of year with surface water present 75%+ canopy cover within 100m of river 100% shoreline cover within 1m of river Measurements are taken every 500m and entered into a GIS

8 Mink Presence/Abundance Track surveys Visual observations Trapping success Mink scat

9 Habitat Suitability and Abundance Habitat Suitability 100% = Excellent 0% = Poor Abundance # Mink / km Pine River Chippewa River Tittabawassee River 70% 59% 51% Study areas have appropriate habitat and support mink year round

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11 Nov.-Jan., 2003 and 04 mink were trapped throughout the Tittabawassee River basin Trapping was conducted by MSU personnel Personnel were trained to ensure consistent handling and storage All samples were handled under strict chain of custody protocols

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13 Mink Necropsy Body weight Body length Sex Age Liver weight Brain weight Baculum length Placental scaring Nutritional status Histology Liver Brain Kidney Jaw Contaminant quantification Liver Adipose

14 Mink Morphological Data Reference N=20 Target N=14 Mean SD Mean SD Body Weight (Male) 872 g 139 g 917 g 175 g Body Weight (Female) 482 g 78.9 g 517 g g Body Length (Male) 56.3 cm 2.71 cm cm 3.04 cm Body Length (Female) Age (Male) 1.8 yrs 0.8 yrs 2.2 yrs 1.1 yrs Age (Female) 2.3 yrs 0.7 yrs 2.7 yrs 0.9 yrs Liver Weight (Male) 51.3 g 10.8 g 51.7 g 14.2 g Liver Weight (Female) 26.4 g 2.23 g 28.7 g 3.87 g Nutritional Status (3=excellent, 1=poor) No significant difference between sites at (p=0.05)

15 Brain weight Liver wt. to brain wt. ratio Baculum length Male to female ratio Placental scars Histology Liver Kidney Brain Jaw Additional Parameters No significant difference between sites at p=0.05

16 Mink Study Design Site-specific, Multiple-year, Multiple-line of evidence approach Habitat suitability Population health Abundance Morphological measurements» Population demographics (sex, age, weight, length)» Nutritional status» Reproductive history ( female )» Baculum length» Organ and jaw histology Dietary exposure assessment Determine dietary composition Analyze identified dietary items for contaminants Predict exposures Tissue based exposure assessment Quantify contaminants in mink liver Quantify contaminants in mink whole body

17 Dietary Composition (Preliminary) Stomach content analysis (first 34 mink ) Scat analysis (in progress)

18 Dietary Exposure : Dietary Composition 4% Alexander, % 3% 10% Fish Crayfish Muskrat Small Mammals Amphibians Vegatation Tittabawassee River site specific 4% 8% 9% 8% 52% 19% 73% 8%

19 Comparison of TEQmammalian congener distribution: mink liver vs. diet 100% 80% 60% 40% 20% 0% Mink liver congener profile Diet as predicted by site-specific liver, and Tillitt BAF (1996) Measured diet based on Alexander composition Measured diet based on sitespecific composition OCDF HpCDF HxCDF HxCDF HxCDF PeCDF 2378-TCDF OCDD HpCDD HxCDD HxCDD HxCDD PeCDD 2378-TCDD

20 Mink Dietary Exposure Pathways Mink Small mammals Muskrats Forage fish Crayfish Frogs Terrestrial invertebrates Aquatic vegetation Benthic invertebrates Soils Sediments

21 Sanford Chippewa Nature Center Smiths Crossing Tittabawassee Twp. Park Freeland Festival Park Imerman Park

22 Food Web Sampling

23 Dietary Exposure: Prey Item TEQ Concentrations 95% UCLs of TEQs WHO mammalian in mink dietary items (ng/kg) collected from one reference and four target sites on the Tittabawassee River Reference Target Sediment Forage fish Muskrat Crayfish Small mammals Vegetation Amphibian

24 Hazard Quotient: Calculation Potential Average Daily Dose (ADD) ADD pot (ngteqwhomammalian /kgbw/d) (C k FR k = m k NIR k ) Normalized Ingestion Rate (NIR) = kg food/kg BW/day based on mean body weight of 1.16 kg and an ingestion rate of 0.15 kg/mink (Halbrook et al., 1999) Hazard Quotient HQ = Toxicity ADD pot (ngteq Reference Value(ngTEQ WHO mammalian WHO /kg BW/d) mammalian /kgbw/d)

25 TRV Derivation NOAEL LOAEL Exposure ng TEQs ng TEQs Profile % PCDF /kg BW /kg BW Endpoint Heaton et al Tillitt et al Saginaw R Kit Survival Bursian et al Housatonic R Bursian et al Saginaw R Kit Survival Reproductive Beckett (unpublished) 2,3,7,8 TCDF Reproductive

26 Mink Dietary Exposure Hazard Quotient LOAEL to NOAEL Based on 95% UCL for Total TEQs in Dietary Items Hazard Quotient Alexander Tittabawassee River 0 Sanford Smith s Crossing Tittabawassee Twp. Park Freeland Festival Park Imerman Park

27 Conclusions (Preliminary) Study area habitat is suitable for Mink Mink are present within the study area year round Mink abundance does not appear to be significantly different between or among target and reference sites Mink population health (based on morphological and histological measurements) within the basin appears to be good and is not different between target and reference sites

28 Conclusions (Preliminary) 2,3,7,8 TCDF and 2,3,4,7,8 PCDF are elevated in target area dietary items The dietary composition of Tittabawassee river mink appear to be similar to that of mink inhabiting similar Michigan rivers The dietary exposure congener profile based on the site-specific diet is similar to that which would be predicted based on sitespecific liver data Dietary exposure hazard quotients based on the site-specific diet and the 95% UCL for target area dietary items ranges from 0.3 to 0.8 for the LOAEL and 1.2 to 3.6 for the NOAEL The majority of the uncertainty associated with the present HQ calculation lies in the availability of an appropriate TRV

29 Acknowledgements All the team members of the Aquatic Toxicology Laboratory >60 Participating Land owners John Shcmude, Saginaw Parks and Recreation Tom Lenon, Chippewa Nature Center Personnel at, Inc., East Lansing, MI The Dow Chemical Company Funding was provided for this study through an unrestricted grant from The Dow Chemical Company to Michigan State University

30 Associated Presentations TP233 (Tuesday) TP229 (Tuesday) TP216 (Tuesday) WP135 (Wednesday) RP103 (Thursday) Assessment of belted kingfisher (Ceryle alcyon) dietary exposure to PCDDsand PCDFs in the Tittabawassee River, MI Tissue Residue Concentrations of PCDDs and PCDFs in Megaloptera: A Comparison to Other Benthic Invertebrate Orders Site-specific dietary exposure assessment of several passerine bird species to PCDDs and PCDFs A Comparison of PCDF and PCDD Bioavailability among Terrestrial Invertebrates from the Tittabawassee River) PCDDs and PCDFs in Small Mammals Foraging in the Tittabawassee River Floodplain, Michigan and its