Ecological Risk Assessment for Wildlife

Ecological Risk Assessment for Wildlife

Dr. Dwayne MooreThe Cadmus Group, Inc.

Dr. Dwayne MooreThe Cadmus Group, Inc.

OverviewOverview

• Assessment endpoints and representative species

• Lines of evidence and measurement endpoints• Site-specific studies• ERA methods

– Exposure assessment– Effects assessment– Risk characterization

• ERA results• Summary of risks to wildlife

• Assessment endpoints and representative species

• Lines of evidence and measurement endpoints• Site-specific studies• ERA methods

– Exposure assessment– Effects assessment– Risk characterization

• ERA results• Summary of risks to wildlife

Assessment Endpoints and Representative SpeciesAssessment Endpoints and Representative Species

• Survival, growth, and reproduction of:– Insectivorous birds

• Tree swallow and American robin

– Piscivorous birds• Osprey and belted kingfisher

– Piscivorous mammals• Mink and river otter

• Survival, growth, and reproduction of:– Insectivorous birds

• Tree swallow and American robin

– Piscivorous birds• Osprey and belted kingfisher

– Piscivorous mammals• Mink and river otter

Assessment Endpoints and Representative SpeciesAssessment Endpoints and Representative Species

• Survival, growth, and reproduction of:– Omnivorous and

carnivorous mammals• Red fox and Northern

short-tailed shrew– Threatened and

endangered species• Bald eagle, American

bittern, small-footed myotis

• Survival, growth, and reproduction of:– Omnivorous and

carnivorous mammals• Red fox and Northern

short-tailed shrew– Threatened and

endangered species• Bald eagle, American

bittern, small-footed myotis

Lines of EvidenceLines of Evidence

T & E Species

ShrewShrewOmn/CarnMammals

MinkMinkPiscivorous Mammals

BeltedKingfisher

Piscivorous Birds

Tree Swallow,Robin

Insectivorous Birds

Site-specific Toxicity

Field StudyModeled Exposure

And Effects

Assessment Endpoint

Modeled Exposure and Effects: Exposure AssessmentModeled Exposure and Effects: Exposure Assessment

Exposure estimated from:

• Diet• COC concentrations• Food intake rate• Foraging range

Exposure estimated from:

• Diet• COC concentrations• Food intake rate• Foraging range

Modeled Exposure and Effects: Exposure AssessmentModeled Exposure and Effects: Exposure Assessment

Probabilistic Risk Assessment• Used distributions when there was uncertainty• Methods propagated uncertainty through

models• Monte Carlo analysis• Probability bounds analysis

Probabilistic Risk Assessment• Used distributions when there was uncertainty• Methods propagated uncertainty through

models• Monte Carlo analysis• Probability bounds analysis

Modeled Exposure and Effects: Example Exposure AnalysisModeled Exposure and Effects: Example Exposure Analysis

Mink exposure model input parameters:

• Body weight (as shown)• Food intake rate inputs• Proportion diet:

–Fish–Invertebrates–Birds–Mammals–Amphibians

Body Weight

0

0.2

0.4

0.6

0.8

1

0.387 0.507 0.628 0.748 0.868 0.988

Weight (kg)

Pro

ba

bil

ity (

%)

Modeled Exposure and Effects: Example OutputModeled Exposure and Effects: Example Output

Mink Exposure to tPCB in Reach 5

0

20

40

60

80

100

0 5 10 15 20 25 30 35 40 45 50 TDI (mg/kg bw/d)

Exc

eeda

nce

Prob

abili

ty (%

)

.

Monte Carlo LPBUPB

Modeled Exposure and Effects: Effects AssessmentModeled Exposure and Effects: Effects Assessment

• Focused on literature studies – survival, reproduction and growth

• Few published studies available for birds• More literature for mammals• In a few cases, site-specific field studies

were used to derive effects metrics

• Focused on literature studies – survival, reproduction and growth

• Few published studies available for birds• More literature for mammals• In a few cases, site-specific field studies

were used to derive effects metrics

Modeled Exposure and Effects: Example Dose-response CurveModeled Exposure and Effects: Example Dose-response Curve

Effects of tPCBs on Reproduction of Mink

0

1

2

3

4

5

6

0 0.2 0.4 0.6Dose (mg/kg bw/d)

Fec

undi

ty (k

its/ f

emal

e)

Modeled Exposure and Effects: Example Risk CurveModeled Exposure and Effects: Example Risk Curve

Mink risk from tPCB in Reach 5 (10% FT)

0

20

40

60

80

100

0 20 40 60 80 100

% Decline in Fecundity

Exce

edan

ce P

robab

ilit

y (

%)

High

Intermediate

LowLow

PISCIVOROUS MAMMALSPISCIVOROUS MAMMALS

Results – Modeled Exposure and Effects for Mink Results – Modeled Exposure and Effects for Mink

Risk to Mink from tPCBs in Reach 5 (100% FT)

0

20

40

60

80

100

0 20 40 60 80 100

% Decline in Fecundity

Ex

ceed

an

ce P

ro

ba

bil

ity

(%

)

Monte CarloLPB - Lower Probability BoundUPB - Upper Probability BoundLow - Intermediate CriterionIntermediate - High Criterion

High

Mink risk from tPCB in Reach 5 (10% FT)

0

20

40

60

80

100

0 20 40 60 80 100

% Decline in Fecundity

Ex

ceed

an

ce

Pro

ba

bil

ity

(%

)

High

Field Studies - MethodsField Studies - Methods

• Field Surveys (Appendix A; Bernstein et al. 2003)– Woodlot recorded presence and relative abundance of

mink and otter in PSA and reference areas from 1998 to 2001

– Bernstein et al. conducted a study in the PSA using similar methods from 2001 to 2003

• Feeding Study (Bursian et al. 2002; Bursian &Yamini 2003)– fed fish collected from Woods Pond– monitored reproduction and development– 6 dose treatments

• Field Surveys (Appendix A; Bernstein et al. 2003)– Woodlot recorded presence and relative abundance of

mink and otter in PSA and reference areas from 1998 to 2001

– Bernstein et al. conducted a study in the PSA using similar methods from 2001 to 2003

• Feeding Study (Bursian et al. 2002; Bursian &Yamini 2003)– fed fish collected from Woods Pond– monitored reproduction and development– 6 dose treatments

Field Studies - ResultsField Studies - Results

• Field surveys (EPA and GE)– mink and otter present in PSA in winter, but rare

otherwise– mink and otter more common in reference areas

• Feeding study– adverse effects on survival of 6 week-old kits– dose-dependent incidence of jaw lesions

• Field surveys (EPA and GE)– mink and otter present in PSA in winter, but rare

otherwise– mink and otter more common in reference areas

• Feeding study– adverse effects on survival of 6 week-old kits– dose-dependent incidence of jaw lesions

Mink Feeding Study: Effect of PCBs on Kit SurvivalMink Feeding Study: Effect of PCBs on Kit Survival

100

*

80

% S

urvi

val

603 Weeks6 Weeks40

20

04Control 0.25 0.5 1 2

PCB Concentration (ppm)

WOE – Piscivorous MammalsWOE – Piscivorous Mammals

Measurement Endpoints

Weighting Value (High, Moderate, Low)

Evidence of Harm (Yes, No, Undetermined)

Magnitude (High, Intermediate, Low)

EPA Moderate/High Yes High Field Surveys

GE Moderate No Low

Feeding Study High Yes High

Modeled Exposure and Effects

Moderate/High Yes High

ERA Results – Insectivorous BirdsERA Results – Insectivorous Birds

• Modeled exposure and effects– intermediate to high risk– moderate weight

• Tree swallow field study (Custer 2002)– monitored reproduction of tree swallows in

nest boxes for 3 years– 3 locations in PSA, 3 reference locations– No obvious adverse effects on reproduction

• American robin field study (Henning 2002)– monitored reproduction of robins for 1 year– within PSA floodplain (contaminated), outside PSA floodplain

(uncontaminated)– No obvious adverse effects on reproduction

• WOE conclusion: Low Risk

• Modeled exposure and effects– intermediate to high risk– moderate weight

• Tree swallow field study (Custer 2002)– monitored reproduction of tree swallows in

nest boxes for 3 years– 3 locations in PSA, 3 reference locations– No obvious adverse effects on reproduction

• American robin field study (Henning 2002)– monitored reproduction of robins for 1 year– within PSA floodplain (contaminated), outside PSA floodplain

(uncontaminated)– No obvious adverse effects on reproduction

• WOE conclusion: Low Risk

Tree Swallow Study: Hatching Success ResultsTree Swallow Study: Hatching Success Results

0

20

40

60

80

100

0 50 100 150 200Total PCBs (ppm)

Egg

Hat

chin

g (%

)

ERA Results – Piscivorous BirdsERA Results – Piscivorous Birds• Modeled exposure and

effects– high risk– moderate weight

• Belted kingfisher field study (Henning 2002)– monitored reproduction of

kingfishers for one year– 9 kingfisher burrows in PSA– no evidence of adverse effects– moderate-high weight

• WOE conclusion: Intermediate to High Risk for some species

• Modeled exposure and effects– high risk– moderate weight

• Belted kingfisher field study (Henning 2002)– monitored reproduction of

kingfishers for one year– 9 kingfisher burrows in PSA– no evidence of adverse effects– moderate-high weight

• WOE conclusion: Intermediate to High Risk for some species

Area

Primary Study Area

0

20

40

60

80

100

0.001 0.01 0.1 1 10 100 1000

Dose (mg/kg bw/d)E

xcee

danc

e Pr

obab

ility

(%)

Monte CarloLPBUPBLow-intermed. criterionIntermed.-high criterion

LPB = Lower probability bound UPB = Upper probability bound

Exposure of Ospreys to tPCBs in Reaches 5 and 6 of the Housatonic River PSA

High

Primary Study Area

OSPREY

ERA Results – Omnivorous and Carnivorous MammalsERA Results – Omnivorous and Carnivorous Mammals

• Modeled exposure and effects– low to high risk– moderate-high weight

• Small mammal field survey (Appendix A)– presence, relative abundance and

habitat usage from 1998 to 2001– low risk– moderate-high weight

• Shrew field study (Boonstra 2002)– survival, reproduction, growth,

population density, sex ratio for 1 year– 6 locations in PSA– intermediate risk– moderate-high weight

• Modeled exposure and effects– low to high risk– moderate-high weight

• Small mammal field survey (Appendix A)– presence, relative abundance and

habitat usage from 1998 to 2001– low risk– moderate-high weight

• Shrew field study (Boonstra 2002)– survival, reproduction, growth,

population density, sex ratio for 1 year– 6 locations in PSA– intermediate risk– moderate-high weight

• WOE conclusion: Intermediate to High Risk for some species in some areas

• WOE conclusion: Intermediate to High Risk for some species in some areas

Site 13

0

20

40

60

80

100

0 20 40 60 80 100

% Mortality at Birth

Exc

eeda

nce

Prob

abili

ty (%

)

Monte CarloLPBUPBLow - Inter. CriterionInter. - High Criterion

High

ERA Results – T & E SpeciesERA Results – T & E Species• Modeled exposure

and effects– High risk for bald

eagles – High risk for American

bitterns– Intermediate risk for

Small-footed myotis• WOE conclusion –

Intermediate to HighRisk

• Modeled exposure and effects– High risk for bald

eagles – High risk for American

bitterns– Intermediate risk for

Small-footed myotis• WOE conclusion –

Intermediate to High

Primary Study Area

0

20

40

60

80

100

1 100

tPCB egg concentration (mg/kg)

Day

s in

PSA

pri

or to

bre

edin

g

High

Mean

Low

Toxicity threshold

Risk

Summary of Risks in the PSASummary of Risks in the PSA

Risk CharacterizationRisk Characterization

• Risks potentially extend to other species (e.g., other shrews)

• ERA below Woods Pond– Mink, otter, and bald eagles– Derived threshold concentrations

for tissues– Compared thresholds to

concentrations measured in fish– When exposure exceeded

threshold = Potential risk– Mink at risk to Reach 10, and otter

at risk to Reach 12

• Risks potentially extend to other species (e.g., other shrews)

• ERA below Woods Pond– Mink, otter, and bald eagles– Derived threshold concentrations

for tissues– Compared thresholds to

concentrations measured in fish– When exposure exceeded

threshold = Potential risk– Mink at risk to Reach 10, and otter

at risk to Reach 12