Monitoring Remedial Effectiveness in a River System

JR Flanders - URS CorpRalph Stahl, Jr., PhD, DABT – DuPont CRG

November 11, 2014SETAC North America Annual Meeting

Vancouver, BC

Goals and Objectives of Monitoring

•Overall goal:

- Assess efficacy of remedy to reduce transport and exposure pathways

- Secondarily to improve WQ and bank habitat

•Specific objectives are to monitor:

- Human and ecological exposure to mercury

- System responses to remediation

- Integrity of corrective action; and

- Provide input to adaptive management framework and relative risk models

Monitoring Features

•Monitoring is:

- Front-loaded

- Iterative, and may be scaled back or modified pending results, and

•Contains short-term and long-term elements

- Differ in terms of spatial and temporal scope

- Similar overall goals

Short-Term Monitoring Objectives

•Objective: test effectiveness of Phase I Interim Measure- Bank stabilization between RRM 0 to 2 to reduce:

• Bank erosion

• Mercury loading

• In-channel mercury exposure

•Short time frame (2-10 years)

•Small spatial scales (BMAs)

•Remediation of downstream reaches informed by remedy success on RRM 0-2

Short-Term Monitoring Elements

• 11 locations within RRM 0-2

• Potential exposure media to be evaluated:

-Near-bank Sediment

-Periphyton

-Transplanted Asiatic Clams

-Pore Water

• Vegetation/Habitat Monitoring

• Monitoring activities to begin in 2015

Results of Pilot Bank Stabilization: 2009 to 2014

Long-Term Monitoring

•Timeframe is >10 years•Focus is South River and SFS River•Objectives:

- Monitor human exposure to MeHg in food

- Monitor ecological exposure to MeHg in aquatic and terrestrial food web

- Monitor potential improvements to water quality and benthic habitat

•Three main components- Human exposure- Ecological exposure

• Aquatic and terrestrial

- Habitat quality

Human Exposure Monitoring

• Three potential exposure media are being evaluated:

- Adult Smallmouth and Largemouth Bass

- Snapping Turtles- Mallard Ducks

• Once annual monitoring• 13 monitoring locations

- South River (4)- South Fork Shenandoah (7)- Shenandoah (2)

• Community outreach- Signage- Physician and clinic outreach- Angler surveys- Outreach to non-English speaking communities

Summary of Bass Tissue Results

Notes: SMB = smallmouth bass, LMB = largemouth bass, SR = South River, SF = South Fork Shenandoah River, SH = Shenandoah River, THg = Total mercury, MeHg = Methylmercury , LTM = Long-Term Monitoring Program. Data are shown as concentrations of mercury species in fish fillets (mean standard deviation). Data are limited to fish >170mm total length sampled within the LTM sample location reaches from 2000 to 2014.

Aquatic Ecological Exposure Monitoring

•Three potential exposure media are being evaluated:- Asiatic Clams- Mayflies- Periphyton- Sediment- Young-of-Year Smallmouth Bass

•Benthic Community Assessment•Eight Monitoring Locations

- South River (5)- South Fork Shenandoah (2)- Middle River (1) (Reference Area)

South River Terrestrial Mercury Trophic Transfer Diagram

Vegetation

Soil

Predatory Bird(Screech Owl, Red-tailed

hawk)

Small Mammals(Deer mouse)

Herbivorous Insects(Tent Caterpillar)

Detritivores(Isopods, Annelids)

Predatory Invertebrates

(Spiders)

Insectivorous Bird (Tree Swallow,

Bluebird, Phoebe, Song sparrow)

Detritus

Grainivorous Birds(Cardinal,

Titmouse, Towhee)

Aquatic Invertebrates

Herbivorous Mammals

(White-tailed Deer)

Trop

hic

Leve

l 1

InvertivorousMammals(Shrew)

Trop

hic

Leve

l 2Tr

ophi

c Le

vel 3

Trop

hic

Leve

l 4

Insectivorous Mammals

(Big brown bat)Isotope data not available

•Isotope data available•Items in bold are focal species in ERA

Legend

Box height proportional to variability of trophic position in model

Sources:Newman, M. 2011. Trophic Analysis and Modeling. Harrisonburg, VA. October. Newman et al. 2011. Environ. Poll. 159 (10): 2840-2844.

Terrestrial Ecological Exposure Monitoring

•Four potential exposure media are being evaluated:

- Earthworms and Soil

- Wolf Spiders

- Carolina Wren

•Nine Monitoring Locations

- South River (5)

- South Fork Shenandoah (4)

Water Quality and Benthic Habitat Quality

•South River benthic habitat impaired RRM 0 to 14:

- Phosphorous and sedimentation

- May improve slowly as BMPs adopted

•Surface water:

- Interannual variability

- Long-term data set

Short-Term Monitoring

Data

Long-Term Monitoring

Data

Adaptive Management

Plan

• Comparison of short-term data with long-term data

• Comparison with long-term trends in climate data

• Methylation status of river

South River Database

Relative Risk Model

DATA SOURCES• Update relative risk

model:• Mercury in biota• Life history data• Water quality data

(temperature, dissolved oxygen)

DATA INTEGRATION

• Use results of relative risk model to adjust management alternatives

• Before-after comparison of data• Place short-term monitoring results

in context of long-term trends• Test hypotheses

• Following periodic review of management program, adjust monitoring as necessary.

How Will the Data be Used?

www.dgif.virginia.gov/fishing/waterbodies/photos/South%20River.JPG

Questions