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Bioaccumulation of mercury and organochlorines in the food web of Lake Washington Jenifer K. McIntyre and David A. Beauchamp School of Aquatic and Fishery Sciences University of Washington

Jenifer K. McIntyre and David A. Beauchamp · Bass Other fish Crayfish Molluscs Oligochaetes Sculpin Stickleback. Sample Processing Total and fork length, weight Scales and/or otoliths

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  • Bioaccumulation of mercury and organochlorines in the

    food web of Lake Washington

    Jenifer K. McIntyre and David A. BeauchampSchool of Aquatic and Fishery Sciences

    University of Washington

  • • Large urban system

    • Popular for fishing

    • Elevated levels of Hg in 1970s

    • Elevated PCB and DDT in tributary sculpin (McCoy & Black 1998)

    Lake Washington

  • Main Project Objectives

    1. Determine current levels of mercury and organochlorines in Lake Washington biota

    2. Explore major pathways governing bioaccumulation in food web

    3. Evaluate whether contaminant levels are of regulatory concern

    4. Develop bioenergetics models to simulate bioaccumulation of Hg and OCs in top predator fishes

  • Talk Structure

    2. Regional Comparisons

    3. Historical Comparison

    1. Bioaccumulation in L. Washington• Age-related accumulation?

    • Lipids in OC bioaccumulation?

    • Benthic versus pelagic pathways?

    • Is biomagnification significant?

  • TrichopteransChironomid

    Cutthroat Pikeminnow

    Zooplankton

    Perch

    Neomysis

    Sockeye SmeltPeamouth

    juv. coho

    juv. chinook

    Bass

    Other fish

    CrayfishMolluscs

    Oligochaetes

    Sculpin

    Stickleback

  • Sample Processing

    Total and fork length, weight

    Scales and/or otoliths

    ~0.1 g dorsal muscle tissue

    Wrapped in aluminum foil, plastic bags

    -20 C until analysis

    Whole bodies ground

    Basic Metrics:

    Ageing:

    Stable Isotopes:

    Storage:

    King County:

  • Fillet : Whole BodyMHg: binds to protein groupsOCs: lipophylic

    MHg: higher in muscle tissue OC: higher in fatty tissues

    [MHg]: =1.44WBF

    WBF[OC]: =0.68

  • Chemical AnalysesMethylmercury – Frontier Geosciences - CVAFS

    Total Mercury – King County ELD - CVAA

    Organochlorines – King County ELD – GC-ECD

    Total DDT = ΣDDT,DDD,DDE

    Total PCB = ΣAroclor 1254,1260

    Total Chlordane = Σα,γ chlordanes

    Not detected: Aroclors 1016,1221,1232,1242,1248

    β, γ BHC (aka HCB)

  • 1. Bioaccumulation

  • [g]

    (μg

    g)

    0

    100

    200

    300

    400

    500

    600

    700[Hg]

    Perch

    Pikeminnow

    Cutthroat

    2 4 6 8 10 12

    0

    100

    200

    300

    400

    500

    0

    500

    1000

    1500

    2000

    2500

    2 4 6 8 10 12

    0

    20

    40

    60

    80[∑DDT] ppb ww

    [∑PCB]

    [∑CHL]

    Fish Age (years)

    Fish age = 42-94% of [x] ppb ww

    82-94%

    66-83%

    59-84%

    42-82%

  • 0.3590.1120.3940.10813PS

    0.7070.3730.8030.64125YP

    0.5280.3300.3610.42812NP

    0.6340.7230.6590.64918CT

    Ln[CHL]

    Ln[PCB]

    Ln[DDT]

    Ln[MHg]

    NSp.

    Correlations with Lipids? p0.05

    Lipids as correlated with Hg as with OCsLipids more correlated with Length than [X]

    Ln(TL)

    0.774

    0.551

    0.827

    -0.108

  • Oct 2002 Mar 2003 Oct 2001 Mar 2002

    Σ DD

    T (p

    pb w

    w)

    (SD

    )

    0

    50

    100

    150

    200

    % L

    ipid

    (wet

    wei

    ght)

    2

    4

    6

    8

    10

    12

    Oct 2001 Mar 2002

    Σ DD

    T (p

    pb w

    w)

    (SD

    )

    0

    20

    40

    60

    80

    % L

    ipid

    (wet

    wei

    ght)

    3

    4

    5

    6

    7

    8

    Lipids and OCsin forage fishes

    • Lipids may co-vary with OC, but not causal

    Stickleback

    Sockeye

    Longfin Smelt

    0+

    1+1+

    2+

    •Lipids track OC in smelt

    • Lipids trends opposite OC in stickleback and sockeye

  • Benthic vs. PelagicUsed δ13C and diet analysis to separate benthic and pelagic feeding guilds

    Compared [X] as a function of trophic position

    Bioaccumulation similar among habitats

    Location of feeding not significant to bioaccumulation in L.Washingtonδ15N (‰ ) ~ Trophic Position

    ΣChlordane

    11 12 13 14 15 16 17 18 19

    Ln[Σ

    CH

    L]

    -1012345

    ΣPCB

    Ln[Σ

    PC

    B]

    2

    4

    6

    8

    10

    ΣDDT

    Ln[Σ

    DD

    T]

    1234567

    MercuryLn

    [Hg]

    -6-5-4-3-2-10

    BenthicPelagic

  • Biomagnification?

    6 8 10 12 14 16 18 20-3

    -2

    -1

    0

    Log10[Hg]=0.1589*δ15N - 3.514

    r2=0.674

    Age may confound biomagnification assessment

    Large fishes

    Small fishes

    Invertebrates

    δ15N ~ Trophic Position

    Log 1

    0[MH

    g]

  • Σ PC

    B (p

    pb w

    w)

    0500

    1000150020002500

    Hg

    (ppb

    ww

    )

    0100200300400500600700

    δ15N (‰) ~ Trophic Position8 10 12 14 16 18 20

    Biomagnificationpikeminnow perch

    cutthroat

    Piscivory dominates

    Piscivory coincides with increased [X]

  • δ15N (‰) ~ Trophic Position6 8 10 12 14 16 18 20

    [Mer

    cury

    ] (pp

    b w

    w)

    0

    20

    40

    60

    80

    100

    Biomagnification

    InvertebratesFishes

  • 2. Regional Comparisons

  • Total Length (mm)100 200 300 400 500 600

    Met

    hylm

    ercu

    ry (p

    pm w

    w)

    0.0

    0.1

    0.2

    0.3

    0.4

    2. Regional Comparisons: Hg

    Mercury concentration is similar in cutthroat trout from L.Washington and adjacent L.Sammamish

    L.Washington

    L.SammamishL.WaL.Wa L.SamL.Sam

  • 2. Regional Comparisons: Hg

    Mose

    s L.

    pper

    Long

    L.Te

    rrel L

    .

    Okan

    agan

    R.

    Bank

    s L.

    alla W

    alla R

    .Pa

    lmer

    L.

    Neum

    an L.

    Black

    L.De

    er L.

    Was

    hingto

    nKit

    sap L

    .Sa

    mish

    L.Lo

    omis

    L.Fa

    zon L

    .

    Vanc

    ouve

    r L.

    Duck

    L

    Merid

    ian L.

    0

    100

    200

    300

    400

    500

    Mercury concentrations in L.Washington bass are similar to bass across Washington State

    Bass

    F/WB = 1.44

    Tota

    l Mer

    cury

    (ppm

    ww

    fille

    t)

    DOE. 2003.

  • THg

    550 ppb dw

    Mercury in sediments is evenly distributed throughout the lake

    Mercury source is atmospheric deposition

    Dat

    a fro

    m K

    ing

    Cou

    nty

    2. Regional Comparisons: Hg

  • Tot

    al D

    DT

    (ppb

    ww

    fille

    t)

    0

    100

    200

    300

    400

    500

    600

    700

    800

    2. Regional Comparisons: DDT

    Non-agricultural

    L.W

    hatc

    om S

    MB

    L.W

    hatc

    om K

    OK

    Can

    al L

    . LM

    B

    LwrD

    uwam

    . ES

    L.S

    amm

    amis

    h C

    T

    Fish

    trap

    Cr.

    RT

    Cle

    ar C

    reek

    CT

    Cow

    litz

    R. M

    WF

    Cow

    litz

    R. C

    T

    Van

    couv

    . L. L

    MB

    Pal

    ouse

    R. N

    P

    Roy

    al L

    . SM

    B

    Sco

    ot. R

    es. L

    MB

    Sco

    ot. R

    es. S

    MB

    Cra

    b C

    reek

    MW

    F

    Red

    rock

    L. L

    MB

    L.W

    ashi

    ngt.

    SM

    B

    L.W

    ashi

    ngto

    n C

    T

    L.W

    ashi

    ngto

    n N

    P

    Lake

    Che

    lan

    RT

    Lake

    Che

    lan

    KO

    K

    Lake

    Che

    lan

    SM

    B

    Yak

    ima

    R. S

    MB

    Cow

    iche

    Cr.

    RT

    ∑DDT (ppb ww fillet)

    F/WB=0.68

    Agricultural

    **

  • Historical DDT Spraying in L.Wa.Basin

    Spraying smoke and DDT for mosquitos in Union Bay, L.Washington in 1957 (photo appeared in Seattle Times, Aug. 6, 1988)

  • 2. Regional Comparison: PCB

    KOK SMB NP MWFSMB RT KOK LMB SMBCarp CT SMB CT NPE.SoleMWF RT

    [PC

    B] p

    pb fi

    llet

    0

    200

    400

    600

    800

    L.Whatcom

    PalouseR.

    Crab Cr.

    L.Chelan

    Vancouver L.Yakim

    a R.L.Sam

    mam

    ishL.W

    ashingtonDuwam

    ish R.Spokane R.

    No PCB Superfund association

    PCB Superfund association

    *

    *

    F/WB=0.68

  • PCB Source to L.Washington?

    PCB Superfund Site 3 miles south of L.Washington

    Expect to see S-N gradient of PCBs in sediments?

    Sediments show patchy hot spots, highest associated with King County CSOs from Seattle

    ΣPCB

    ND at 38 ppb/Aroclor

    577 ppb dw

    Dat

    a fro

    m K

    ing

    Cou

    nty

    Cedar River

  • 3. Historical Comparison

  • 3. Historical – Hg in sediment

    Sediment [Hg] is half what it was during 1970s

    0.5x

    [Hg] ppm dw

    ‘70 ‘90‘50‘30‘10

    1970s

    1990s

  • 3. Historical Comparison: Hg

    Internal recycling of mercury?

    Total Length (mm)50 100 150 200 250 300 350 400

    0.0

    0.1

    0.2

    0.3

    0.4

    F/WB=1.44

    Total Length (mm)100 200 300 400 500 600 700

    Tota

    l Mer

    cury

    (ppm

    ww

    )

    0.0

    0.2

    0.4

    0.6

    0.8

    1.0

    19742002

    F/WB=1.44

    Tota

    l mer

    cury

    (ppm

    ww

    )

    0.00

    0.02

    0.04

    0.06

    0.08

    0.10

    0.12

    0.14

    Barnes 1973Current study OctoberCurrent study March

    ZOOP JUVSOC

    STKB LONGSMELT

  • Conclusions• Mercury and organochlorines present at

    detectable levels in Lake Washington biota

    • Age the best predictor of contaminant concentration among predatory fishes

    • Lipids not causally related to contaminant levels

    • Benthic and pelagic foodwebs similar biomagnification potential

    • Piscivory important to bioaccumulation

  • Conclusions• Hg source atmospheric, concentrations in

    Lake Washington fishes were similar to other lakes in the State

    • Organochlorine source is local, concentrations in Lake Washington fishes were elevated compared with other waters of Washington State

    • [Hg] in biota has not changed since the 1970s – internal recycling of contaminants important

  • AcknowledgementsH. Mason Keeler endowment from UW School of Aquatic and Fishery Sciences

    King County Department of Natural Resources

    King County Environmental Laboratory

    Dr. David Beauchamp (UW, SAFS)

    Dr. Jonathan Frodge (KC DNR)

  • First Winter: Copepods

    % Change in Weight-50 0 50 100 150 200 250 300

    % C

    hang

    e in

    Hg

    Bod

    y B

    urde

    n

    0

    200

    400

    600

    800

    1000

    1. Pathways – Forage fishes - Hg

    Growth and diet explain seasonal Hg in forage fishes

    LS 1+

    SSSB

    LS 2+LS 0+

    Second winter: high [Hg] mysids, ?[Hg] larval fish

    First Summer:

    High [Hg] Daphnia

    Bio

    accu

    mul

    atio

    n

    Growth

  • % Change in Weight-100 -50 0 50 100 150 200%

    Cha

    nge

    in O

    GC

    Bod

    y B

    urde

    n

    -200

    0

    200

    400

    600

    800

    1000

    1200

    1400

    1600

    1. Pathways - Forage Fishes - OC

    SS SB

    LS 2+ LS 0+∑CHL∑PCB∑DDT

    LS 1+ First Summer: low [OGC] Daphnia

    First Winter: Copepods

    Second Winter: higher [OGC] mysids, ?[OGC] larval fish

    Growth and diet also explain OC dynamics

    Bio

    accu

    mul

    atio

    n

    Growth

  • Internal Recycling of Contaminants

    [X]

    = perturbation of sediments by fish and invertebrates

    Bioturbation

  • “In the Great Lakes…it is now accepted that the internal recycling caused by the coupled

    processes of bioturbation and resuspensionare responsible for the continuing elevated

    concentrations of trace contaminants in fish…”

    B.J. Eadie, L.Michigan Mass Balance Project

    Internal Recycling of Contaminants

    Another example:Lake Hartwell, 10 to 50-fold reduction [PCB] sediment

    over ~25 years, no change in fish over 14 years

    Brenner et al. 2004. ES&T 38:2328

  • Lake Washington MeHg (g/yr)

    30

    5. Biotransport of Contaminants

    ?

    ??

    ??

    ?

    ?

    ? Remineralization? In-situ methylation

    ? Groundwater

    An example of the far-reaching impacts of our chemical legacy on ‘natural’systems

    Biotransport likely much less significant than in arctic systems –less fish, more background contamination

    5.4

  • 3. Historical Comparison: OC

    [∑PCB] ppb dw

    [∑DDT] ppb dw

    1970s

    1990s2x

    1970s

    1990s3x

    [∑PCB]

    [∑DDT]

    ‘70 ‘90‘50‘30

    ‘70 ‘90‘50‘30

  • Total Length (mm)100 200 300 400 500 600

    δ13 C

    ~ F

    eedi

    ng L

    ocat

    ion

    -32

    -30

    -28

    -26

    -24

    -22

    -20 Carbon isotopes indicate feeding location

    Benthic vs. Pelagic Uptake

    Cannot use carbon isotopes alone to assess bioaccumulation pathways

    Ontogeny in feeding location

    Benthic

    Pelagic

  • Benthic vs. Pelagic Uptake

    Total Length (mm)100 200 300 400 500 600

    δ15 N

    (‰) ~

    Tro

    phic

    Pos

    ition

    10

    12

    14

    16

    18

    20

    Trophic position may confound analysis

  • ContaminationDDE/ΣDDTSystem

    50-70%Great Lakes Newsome & Andrews 1993

    24%Hong Kong marketsChan et al. 1999

    10-25%Coastal ChinaKlumpp et al. 2002

    55-98%Columbia R. BasinEPA 2002

    59-88%L.WhatcomDOE 1999

    54-75%Lake Wa.McIntyre 2004

    Historical

    Historical

    Historical

    Historical

    Continuing

    Continuing