Ecological Risk Assessment for Benthic Invertebrates

Ecological Risk Assessment for Benthic Invertebrates

Gary Lawrence (EVS Environment Consultants)Gary Lawrence (EVS Environment Consultants)

Assessment Endpoint and Representative SpeciesAssessment Endpoint and Representative Species

• Assessment Endpoint –community structure, survival, growth, and reproduction

• (1) “Whole” – examine entire benthic community assemblage

• (2) “Specific” – indicator test species:Chironomus tentans (midge);Hyalella azteca (amphipod);Daphnia magna, Ceriodaphnia dubia(crustaceans);Lumbriculus variegatus (worm)

•• Assessment Endpoint Assessment Endpoint ––community structure, survival, growth, community structure, survival, growth, and reproductionand reproduction

•• (1) “Whole” (1) “Whole” –– examine entire benthic examine entire benthic community assemblagecommunity assemblage

•• (2) “Specific” (2) “Specific” –– indicator test species:indicator test species:Chironomus tentansChironomus tentans (midge);(midge);Hyalella aztecaHyalella azteca (amphipod);(amphipod);Daphnia magna, Daphnia magna, Ceriodaphnia dubiaCeriodaphnia dubia(crustaceans);(crustaceans);Lumbriculus variegatusLumbriculus variegatus (worm)(worm)

Measurement Endpoints and Lines of EvidenceMeasurement Endpoints and Lines of Evidence

Fieldstudies

Site-specifictoxicity

Triad

Chemistry

1. 2.

3.

Community compositionCommunity composition

(a) Long-term laboratory tests (2 species)

(b) Field tests (4 species)(c) Toxicity Identification

(TIE)

(a) Long-term laboratory tests (2 species)

(b) Field tests (4 species)(c) Toxicity Identification

(TIE)

(a) Sediment(b) Water(c) Biota

(a) Sediment(b) Water(c) Biota

SEDIMENT QUALITY

TRIAD

SEDIMENT QUALITY

TRIAD

River Mite: N/AHW-SE000161

H3-SD0437Q2Benttiie Oamnmnlty Stations Witlwut Toxlcfly Testing

Benthrc Commu nity Stations With Towcity TQBiJna

Reach BreaksRiver Mile: 130.32

/ Roads

I 1 Hydrography

Reach 5B r Housatonic Rivor Basin Boundary

Mies: -Codeinlaftmxof eschlD rapi«oiri"ilnn[«iBd'romanct«UJi»ii»<fcf twwlc IrrwrrobfM* ERA.• Button 8A «*• ma/nxM 12 nurtr* tram AaUni * . wd M I imaif 1a MBixMay taicHy any.River Mile: 12B.7

H3-SE000116

I Reach 5C

River Mile: 126.36H3-SE0003S9

River Mile: 125.65H3-SEEC0031

River Mile: 124.5H3-SE000246

Exposure AssessmentExposure Assessment

• Biota tissue, water, and sediment data• Contaminants of Concern from invertebrate-

specific screening: PCBs, dioxins/furans, PAHs, and some metals

• PCBs are the dominant chemical stressor

• Biota tissue, water, and sediment data• Contaminants of Concern from invertebrate-

specific screening: PCBs, dioxins/furans, PAHs, and some metals

• PCBs are the dominant chemical stressor

Habitat/Substrate Change in Primary Study Area

Habitat/Substrate Change in Primary Study Area

0

20

40

60

80

100

A1 A2 A3 1 2 3 4 5 6 7 8 9 R4

Med

ian

Perc

ent F

ines

(%)

0%

2%

4%

6%

8%

10%

Med

ian

TOC

Percent Fines Total Organic Carbon (%)

A

B

Upstream Downstream

A - (1.5 mi below Holmes Rd.)A - (1.5 mi below Holmes Rd.)

B - (Woods Pond Headwaters)B - (Woods Pond Headwaters)

“sandy”

“silty”

Sediment tPCB Concentrations in Benthic Community Samples (log scale)

Sediment tPCB Concentrations in Benthic Community Samples (log scale)

0.1

1

10

100

1000

A1 A2 A3 1 2 3 4 5 6 7 8 9 R4

Location ID

Conc

entra

tion

oftP

CB

(mg/

kg)

Median of 12 replicates

Mean of 12 replicates

Replicate concentration, assuming non-detected values equal tohalf MDL

0.1

1

10

100

1000

A1 A2 A3 1 2 3 4 5 6 7 8 9 R4

Location ID

Conc

entra

tion

oftP

CB

(mg/

kg)

Median of 12 replicates

Mean of 12 replicates

Replicate concentration, assuming non-detected values equal tohalf MDL

Upstream Downstream

-NOTE:-- large variability- PSA elevated above references- gradient observed

PSA RR

Effects Assessment - MethodsEffects Assessment - Methods

• Toxicity tests (laboratory, field, and TIE); Wright State University (Dr. G.A. Burton)

• Benthic community measures • Literature reviews (sediment, tissue)• Concentration-response evaluation

• Toxicity tests (laboratory, field, and TIE); Wright State University (Dr. G.A. Burton)

• Benthic community measures • Literature reviews (sediment, tissue)• Concentration-response evaluation

Laboratory Hyalella Toxicity (42-day Reproduction)

Laboratory Hyalella Toxicity (42-day Reproduction)

72

31213

(no survivors)

8.7

0.28

0.028

NA

0

10

20

30

40

50

60

70

80

T-Control A1 A3 4 7 8A 8

Station Location

Mea

n nu

mbe

r of o

ffspr

ing

[+ S

D]

Negative control (clean

sediment/water

Housatonic River contaminated stations

Field reference stations

Field Daphnia Toxicity Survival (48-h Survival)Field Daphnia Toxicity Survival (48-h Survival)

522(no survivors)

139(no survivors)

7.3

0.95

0.380.0001NA

0

25

50

75

100

LabControl

A1 A3 4 5 7 8

Station Location

Mea

n Su

rviv

al (%

) [+

SD]

Field reference stations

Housatonic River contaminated stations

Sediment tPCB concentration (ppm) in italics

Toxicity Identification Evaluation (TIE)

Toxicity Identification Evaluation (TIE)

• Wright State University. (USEPA protocols)

• Ceriodaphnia dubia• Modified toxicity test

conditions (treatments) and observed changes in toxicity

• Non-polar organics (PCBs, dioxins/furans, PAHs) identified as toxicant group

• Metals, others excluded

•• Wright State University. Wright State University. (USEPA protocols)(USEPA protocols)

•• Ceriodaphnia dubiaCeriodaphnia dubia•• Modified toxicity test Modified toxicity test

conditions (treatments) and conditions (treatments) and observed changes in toxicityobserved changes in toxicity

•• NonNon--polar organics (PCBs, polar organics (PCBs, dioxins/furans, PAHs) dioxins/furans, PAHs) identified as toxicant groupidentified as toxicant group

•• Metals, others excludedMetals, others excluded

Benthic Community StructureBenthic Community Structure

• Taxonomy and PCB chemistry• Investigated individual metrics (e.g., total abundance,

species numbers) and combined metrics (multivariate methods)

• 12 replicates (individual grab samples) collected from each of 13 stations (8 “sandy” + 5 “silty”)

•• Taxonomy and PCB chemistryTaxonomy and PCB chemistry•• Investigated individual metrics (e.g., total abundance, Investigated individual metrics (e.g., total abundance,

species numbers) and combined metrics (multivariate species numbers) and combined metrics (multivariate methods)methods)

•• 12 replicates (individual grab samples) collected from 12 replicates (individual grab samples) collected from each of 13 stations (8 “sandy” + 5 “each of 13 stations (8 “sandy” + 5 “siltysilty”)”)

Benthic Community Structure – Taxonomic Richness

Benthic Community Structure – Taxonomic Richness

Coarse-Grained Sites

0

5

10

15

20

25

30

35

A1 A2 A3 1 2 3 4 5

Station ID

Sedi

men

t tPC

B (p

pm) o

r nu

mbe

r of t

axa

Number of Species (+ SD)Median tPCB (ppm)

Fine-Grained Sites

0

5

10

15

20

25

30

35

6 7 8 9 R4

Station ID

Number of Species (+ SD)Median tPCB] (ppm)

Housatonic River contaminated stations

Housatonic River contaminated stationsReference Ref.

Effects Assessment - ChemistryEffects Assessment - Chemistry

• Literature review of tPCB effects in tissue and sediment

• Concentration-response assessment for site-specific studies

• Good agreement between approaches• Threshold level identified: 3 ppm tPCB

• Literature review of tPCB effects in tissue and sediment

• Concentration-response assessment for site-specific studies

• Good agreement between approaches• Threshold level identified: 3 ppm tPCB

Risk Characterization – Lines of Evidence (continued)

Risk Characterization – Lines of Evidence (continued)

Station ID

Coarse-Grained (Sandy) Fine-Grained (Silty) Major Line of Evidence

1 2 3 4 5 6 7 8A 8 9

Toxicity (11 endpoints)

- - - - -

Benthic Community (5 endpoints)

-

Chemistry (7 endpoints)

OVERALL

= major impact = moderate impact = negligible impact

Risk CharacterizationRisk Characterization

Coarse-Grained Sediments

Measurement Endpoints Weighting Evidence of

Harm

Magnitude

C. Chemical Measures

C-1. Water chemisty Low/ Mod Yes Intermediate

C-2. Sediment chemistry Low/ Mod Yes High

C-3. Tissue chemistry Moderate Yes Intermediate

T. Toxicological Measures

T-1. Sediment toxicity (laboratory) Mod/ High Yes High

T-2. Sediment toxicity (field) Mod/ High Yes Intermediate

T-3. Indications of PCB as toxicity driver in TIE Moderate Yes High

B. Benthic Community Measures

B-1. Abundance, richness, and biomass of invertebrates, relative to reference Moderate Yes Intermediate

B-2. Benthic community structure, using multivariate assessment Moderate Yes Intermediate

B-3. Modified Hilsenhoff Biotic Index (MHBI) indicator of organic pollution Moderate No —

Summary of Risks (By Reach)

Summary of Risks (By Reach)

0.1

1

10

100

5A 5B 5C 5D 6

Haz

ard

Quo

tient

.

X

Max

MinMC 25th

MC 75thMeanMedian

3 ppm

CFS

T

Extrapolation of RisksExtrapolation of Risks

• No extrapolation to other species necessary

• Risks reduced downstream of Woods Pond

• Risks negligible below Great Barrington (PCB < 3 ppm)

• No extrapolation to other species necessary

• Risks reduced downstream of Woods Pond

• Risks negligible below Great Barrington (PCB < 3 ppm)