Tittabawassee River Ecological Studies Update

Transcription

1 Tittabawassee River Ecological Studies Update November 2005

2 Objectives of presentation Discuss preliminary data available to date in context of ongoing studies Release mink liver concentration data Open forum to view SETAC posters 2

3 Conceptual Site Model Raptor Heron Passerine birds Invertebrates Small mammals Soil Muskrat Kingfisher Benthic invertebrates Forage fish Mink Sediment 3

4 Tittabawassee River Ecological Studies Food web dietary items Song birds Fish eating birds Raptors Migratory waterfowl Mink 4

5 Three lines of evidence Dietary exposure assessment Tissue based exposure assessment Population Health and Sustainability Population health measurements 5

6 Tittabawassee River Ecological Studies Food web dietary items 6

7 Conceptual Site Model Raptor Heron Passerine birds Invertebrates Small mammals Soil Muskrat Kingfisher Benthic invertebrates Forage fish Mink Sediment 7

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9 Tittabawassee River Ecological Studies Song birds (a.k.a. passerines) Tree swallows American robin Eastern bluebird House wren 9

10 Passerine 1: Dietary exposure House wren Eastern bluebird Tree swallow Other Other Orthoptera Other Diptera 13.1% Araneae 4.9% 9.9% Hymenoptera 4.9% 7.0% 7.7% 9.0% Araneae 48.9% Lepidoptera 7.3% Oligochaeta 46.5% 16.2% Ephemeroptera 36.1% Tricoptera 21.4% 31.3% Lepidoptera 35.9% Diptera Orthoptera 10

11 Passerine 1: Dietary exposure TEQ WHO-avian in passerine dietary items Reference concentrations (ng/kg ww) Target concentrations (ng/kg ww) x Reference Target 32x 70x 339x 12x 6x 39x 139x Diptera Oligochaeta Araneae Lepidoptera Ephemeroptera Orthoptera Other Tricoptera MICHIGAN STATE UNIVERSITY

12 Passerine 1: Dietary exposure Mean estimated dietary dose TEQ WHO-avian (ng/kg/d) Site Tree swallow House wren Eastern bluebird Reference sites Target sites

13 Passerine 2: Tissue based exposure assessment Samples have been collected Fresh eggs Addled eggs Nestlings Preliminary analytical results will be available in

14 Passerine 3: Population health 202 nest boxes placed at 2 reference sites (n=69) and 4 target sites (n=133) First year productivity data complete clutch size hatching success Fledging success First year nest attentiveness complete >600 birds banded including 400 nestlings 14

15 Passerine Preliminary observations Expected species present Occupancy exceeded expectations (Ref=82%, Target=87%) No deformities observed No obvious differences in productivity Overall site-specific diets comparable to literature based diets Dietary exposure based on TEQ WHO-avian is made up largely of PCDF congeners target dietary items were 6-339x greater than at reference sites Congener profile downstream is similar among sites (data not presented) 15

16 Tittabawassee River Ecological Studies Fish eating birds (a.k.a. piscivorous) Great Blue Heron Belted Kingfisher 16

17 Kingfisher 1: Dietary exposure 17

18 Kingfisher 1: Dietary exposure Crayfish 41% Crayfish 13% Crayfish 13% Amphibian 5% Fish 59% Fish Fish 87% 82% Salyer and Lagler, 1946 Davis, 1982 Tittabawassee River,

19 Kingfisher 1: Dietary exposure 95% UCL TEQ WHO-avian in dietary items (ng/kg) Reference Sediment 1.92 Amphibian 1.36 Target Crayfish * 422* Forage fish * 272 *actual value reported when n=1 19

20 Kingfisher 1: Dietary exposure TEQ WHO-avian congener profile in dietary items (ng/kg) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Fish Crayfish Frog HxCDF PeCDF PeCDF 2378-TCDF PeCDD 2378-TCDD 20

21 What are Hazard Quotients (HQs)? HQ = Exposure level Effect level HQs are numerical expressions of hazard which are determined by dividing an exposure concentration by an appropriate reference dose HQs < 1 are considered no risk HQs > 1 are considered to represent a potential hazard to receptors 21

22 Mallard NOEL (Brunstrom 1988) Kingfisher 1: Dietary exposure Relative species TEQ sensitivity 50 TEQ Concentrations (μg/kg egg, ww) MICHIGAN STATE UNIVERSITY Ring-necked pheasant LOEL (Nosek 1992) Wood duck LOEL (White 1995) Chicken LOEL (Verrett 1970)

23 Kingfisher 1: Dietary exposure 14 NOAEL to LOAEL HQ of 95% UCL Dietary Exposure HQ 12 Salyer and Lagler, 1946 Davis, Tittabawassee River Reference Target 3 Target 4 Target 5 Target 6 23

24 Kingfisher 2: Tissue based exposure assessment Samples have been collected Fresh eggs Addled eggs Nestlings Preliminary analytical results will be available in

25 Kingfisher 3: Population health Area Eggs/ nest Eggs sampled Nestlings/ nest Nestlings sampled Prey remains Nestlings fledged Target No 3 Target Yes 3 Target Yes Predated Target Yes 3 Target Yes Failed Target Yes 4 Ref Yes 4 Ref Yes Ref Yes Ref No Failed Failed Predated 25

26 Kingfisher Preliminary observations ~90% of the TEQs in dietary items can be attributed to 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF. Dietary composition on TR was similar to other rivers in the Midwest. Present sample size led to the use of 95% UCL dietary exposure data in the calculation of HQs for a conservative estimate of risk. Although some of the HQs are greater than 1, it is not certain that belted kingfisher along the Tittabawassee River are experiencing adverse effects. These are first-year data from a multi-year study that is utilizing a multiple lines of evidence approach, including dietary and tissue-based assessments and population health assessment. 26

27 Tittabawassee River Ecological Studies Raptors 27

28 Raptor 1: Dietary exposure Prey remains have been collected Classification results expected in 2006 Dietary items have been sampled 28

29 Raptor 2: Tissue based exposure assessment Samples have been collected Fresh eggs Addled eggs Nestling plasma Adult plasma Preliminary results will be available in

30 Raptor 3: Population health Owl Response, Nesting Platforms and Active Nest Locations Active Nest 1 Nestling Active Nest 1 Nestling Adult Pair Response Single Adult Response Fledgling Response Nest Platform location Active Nest 1 Nestling

31 Great Horned Owl 3: Population health Breeding Area Caldwell Freeland Imerman Saginaw Bay Nesting activity Eggs /nest Yes 1 Nestlings /nest Prey remains 1 Yes Yes 1 1 Yes Yes 1 1 Yes Yes 2 2 Yes Sanford No 0 No Pine No 0 No Chippewa No 0 No Shiawassee Yes 2 1 Yes 31

32 Raptor Preliminary observations Great Horned Owls (GHO) are defending Territories throughout the river basin Nesting platforms are being utilized First year nestlings have survived through September First year diets have a higher than expected occurrence of cottontail rabbit (data not presented) 32

33 Tittabawassee River Ecological Studies Migratory waterfowl Wood duck Merganser 33

34 Migratory waterfowl Dietary exposure Not within study design Tissue residue concentrations No data currently available from MSU portion of study 34

35 Waterfowl Preliminary observations Waterfowl nest box occupancy was higher than expected (Ref=55%, Target=67%) Wood duck and merganser productivity appears to be good Sample size requirements will likely be met in

36 Tittabawassee River Ecological Studies Mink 36

37 Why are mink important receptors? Top of aquatic food chain Very sensitive to dioxin like effects Known to be present in this ecosystem Forage range entirely within the river and floodplain 37

38 Mink 1: Dietary exposure Stomach content analysis (presented) Scat analysis 38

39 Mink 1: Dietary exposure Alexander, % 2% 4% 8% 10% Fish Crayfish Muskrat Small Mammals Amphibians Vegetation 8% 19% Tittabawassee River site specific 4% 9% 52% 73% 8% 39

40 Mink 1: Dietary exposure Prey item 95% UCL TEQ WHO-mammalian conc. (ng/kg) Reference Target Sediment Forage fish Muskrat Crayfish Small mammals Vegetation Amphibian

41 Mink 1: Dietary exposure Comparison of TEQ WHO-mammalian congener distribution: mink liver vs. diet 100% 80% 60% HxCDF HxCDF PeCDF 2378-TCDF PeCDD 2378-TCDD 40% 20% MICHIGAN STATE UNIVERSITY 0% Mink liver congener profile Diet as predicted by sitespecific liver, and Tillitt BAF (1996) Measured diet based on sitespecific composition 41

42 Mink 1: Dietary exposure TRV Derivation Heaton et al Tillitt et al Exposure Profile % PCDF NOAEL ng TEQs /kg BW LOAEL ng TEQs /kg BW Saginaw R Endpoint Kit Survival Bursian et al Housatonic R Kit Survival Bursian et al Beckett (unpublished) Saginaw R ,3,7,8 TCDF Reproductive - Reproductive Study selected for conservative preliminary evaluation 42

43 Mink 1: Dietary exposure Hazard Quotient LOAEL to NOAEL HQ of 95% UCL Dietary Exposure Alexander Tittabawassee River Sanford Smith s Crossing Tittabawassee Twp. Park Freeland Festival Park Imerman Park 43

44 Mink 2: Tissue based exposure assessment Mink liver TEQ WHO-mammalian (ng/kg) Reference areas Target areas 44

45 Mink 2: Tissue based exposure assessment Mink liver TEQ WHO-mammalian (ng/kg) Sanford Chippewa Nature Center Tittabawassee Upstream Smiths Crossing Tittabawassee Township Park Freeland Festival Park Imerman Park 45 MICHIGAN STATE UNIVERSITY

46 Mink 2: Tissue based exposure assessment TRV Derivation Heaton et al Tillitt et al Exposure Profile % PCDF NOAEL ng TEQs /kg ww LOAEL ng TEQs /kg BW Saginaw R Endpoint Kit Survival Bursian et al Housatonic R Kit Survival Study selected for conservative preliminary evaluation 46

47 Mink 2: Tissue based exposure assessment liver TEQ based HQs (Burs Sanford Chippewa Nature Center Tittabawassee Upstream Smiths Crossing Tittabawassee Township Park Freeland Festival Park Imerman Park HQ 47 MICHIGAN STATE UNIVERSITY

48 Mink: Exposure assessment comparison Liver and Dietary HQs (TEQ) Dietary Based HQs Liver Based HQs HQ Sanford Chippewa Nature Center Tittabawassee Upstream Smiths Crossing Tittabawassee Township Park Freeland Festival Park Imerman Park

49 Mink 3: Population health Track surveys Visual observations Trapping success Mink scat 49

50 Mink 3: Population health Habitat Suitability and Abundance Habitat Suitability 100% = Excellent 0% = Poor Pine River Chippewa River Tittabawassee River 70% 59% 51% # Mink / km Study areas have appropriate habitat and support mink year round 50

51 Mink MICHIGAN STATE UNIVERSITY 3: Population health 51

52 Mink 3: Population health Mink Necropsy Body weight Body length Sex Age Liver weight Brain weight Baculum length Placental scaring Nutritional status Histology Liver Brain Kidney Jaw 52

53 Mink MICHIGAN STATE UNIVERSITY 3: Population health Mink Morphological Data Body Weight (Male) Body Weight (Female) Body Length (Male) Mean Reference N=20 SD Mean Target N=14 SD 872 g 139 g 917 g 175 g 482 g 78.9 g 517 g 16.2 g 56.3 cm 2.7 cm 57.5 cm 3.0 cm Body Length (Female) Age (Male) Age (Female) Liver Weight (Male) Liver Weight (Female) Nutritional Status (3=excellent, 1=poor) 1.8 yrs 0.8 yrs 2.2 yrs 1.1 yrs 2.3 yrs 0.7 yrs 2.7 yrs 0.9 yrs 51.3 g 10.8 g 51.7 g 14.2 g 26.4 g 2.23 g 28.7 g 3.87 g No significant difference between sites at (p=0.05) 53

54 Mink 3: Population health Additional Parameters Brain weight Liver wt. to brain wt. ratio Baculum length Male to female ratio Placental scars Histology Liver Kidney Brain Jaw No significant difference between sites at p=

55 Mink Preliminary observations 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 55

56 Mink Preliminary observations 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 site-specific liver data Dietary exposure hazard quotients based on the sitespecific 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 56

57 Matthew Zwiernik, John John Giesy, Ph.D.

58 SETAC Presentations MICHIGAN STATE UNIVERSITY PCDDs and PCDFs in aquatic and terrestrial food webs of the Tittabawassee River, Michigan Assessment of belted kingfisher (Ceryle alcyon) dietary exposure to PCDDs and 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 58