Item 1: Agenda Review

!  13th Annual BOG Review Panel Meeting!!  Quick round of updates!  Clean Lakes final report!  Sampling plan for the Bight!  Review of 2016 results!  Update on 2017 sampling!  Timeline for 2018!  Make sure we hear from the Panel

•  Format for each item: Presentation, Panel, general discussion

!  Three-year contracts in place

!  WPCL out of the contract analytical chemistry business!  2015 Bass Lakes data report – not completed yet!  Statewide Mercury Water Quality Objectives - adopted in May!  Mercury Control Program for Reservoirs - draft staff report out for

peer review

!  OEHHA advisories - new advisories!  Datasets recently added to CEDEN: SRWP 2004, RMP San Leandro

Bay 2016!  Delta RMP mercury monitoring continues: 7 fish sites!  USGS Webinar Series on mercury in reservoirs – begins 2/14 at

10AM

!  Desired outcome: Obtain input on the study from the Review Panel and stakeholders via a group discussion. Input will guide preparation of the final report and fact sheet.

!  Written corrections are requested by February 20.

What’s New1.  The words “Clean” and “Cleanest” have been

stricken from the record2.  Combined the data for statewide survey and

Region 7 in key figures3.  Revised “Why?” analysis

•  Split out water data by stratum•  Additional data gathering and evaluation•  Revised linear mixed-effects models•  Referenced the Reservoir TMDL staff report analysis

4.  Completed incomplete items5.  Extensive edits

Purpose of the Technical Report

!  Document and allow peer review of the technical foundation for the study and other for other communication products•  The Portal•  Fact sheet(s)•  Press release

Management Value

!  Informing the Reservoir TMDL!  Informing fish consumers !  Use in Integrated Report?

Figure 1. Locations sampled.

Figure 5a. Spatial pattern in mercury concentrations in largemouth bass - statewide survey and Region 7 Study. Thresholds based on ATLs for women over 45 and men. Colors based on length-adjusted (350 mm) mean concentrations. River locations indicated by diamonds.

Figure 5b. Spatial pattern in mercury concentrations in largemouth bass - statewide survey and Region 7 Study. Thresholds based on ATLs for women 18-45 and children 1-17. Colors based on length-adjusted (350 mm) mean concentrations. River locations indicated by diamonds.

MQ1: Which popular lakes in California can be confirmed to have relatively low concentrations of contaminants in sport fish? !  Women over 45 and Men

•  7 lakes meet all criteria•  8 more could meet all criteria with one more round of

sampling

!  Women 18-45 and Children 1-17•  1 lake met all criteria•  5 more could with one more round of sampling

!  Mercury•  Many lakes confirmed to be at the clean end of the

distribution

Sampling Design – 23 Lakes

Sample Type Number of Samples per Lake

Parameters

Largemouth Bass 10 individuals (size standardized to 350 mm)

Hg

Prey Fish 2-4 composites of ~10 individuals each

Hg, Se

Water Samples 2 samples (subsurface & near-bottom) at 3 locations in each lake (“Bank” or “Open Water”)

THg, MeHg, DOC, SO4, Chla

Sediment Samples 1 sample at 3 locations, corresponding with Water Samples

THg

Lake Properties NA Dam Height, Surface Area, Perimeter, Elevation, Lake Shape Index

Lakes with Length-adjusted Largemouth Bass • 157 lakes sampled to date

• 11 of 16 lakes in lowest 10th percentile from Clean Lakes and Region 7 Studies (Clean Lakes in blue, Region 7 in pink)

• Distribution very similar to the distribution in USEPA’s national lakes survey

Largemouth Bass • 19 lakes

• Lakewide means

• Range 0.02 – 0.28 ppm

Figure16. Mean350mmlargemouthbassmercuryforeachlake,orderedfromhightolowconcentration,alongwithorderedbarplotsforotherparameters.Barsindicatearithmeticmeans,errorbarsrepresentonestandarderror.

Hg in Largemouth Bass

Hg in Prey Fish

Se in Prey Fish

THg in Sediment

THg in Water Chl(a) in Water DOC in Water Sulfate in Water

Dam Height

MeHg in Water

ConductivityLake Shape Bottom DO

MeHg in Water: Open, Surface

MeHg in Water: Open, Bottom

MeHg in Water: Bank, Surface

Table4a. Arithmeticmeanvaluesforconcentrationsinfish,sediment,andwater;andlakepropertiesforallofthelakesinthestatewidesurvey.Bassdataaremeansfor12individuals.Preyfishdataaremeansacrosstwoormorespecies.*-AverageofuncensoredvaluesbelowMDLs.**-AverageincludingbothdetectedvaluesanduncensoredvaluesbelowMDLs.

Fish

Largemouth

Bass (350

mm std

size)

Mercury

(ug/g ww)

Prey Fish

Mercury

(ug/g ww)

Prey Fish

Selenium

(ug/g dw)

Dam

Height (ft)

Lake

Surface

Area

(acres)

Lake

Perimeter

(km)

Lake

Elevation

(ft)

Lake

Shape

Index

Lake-wide

Average

Total

Mercury

(mg/kg

dw)

Total

Mercury,

Bank

(mg/kg

dw)

Total

Mercury,

Open

Water

(mg/kg

dw)

Lake Merced 0.28 0.022 0.31 219 5.7 22 1.5 0.16 0.01 0.24

Lake Gregory 0.25 0.029 0.78 90 82 4.0 4551 1.7 0.10 0.08 0.11

Lake Jennings 0.25 0.059 4.56 200 131 6.6 697 2.3 0.03 0.02 0.04

Legg Lake 0.18 0.012 1.60 27 2.5 199 1.9 0.10 0.07 0.11

Castaic Lagoon 0.15 0.024 1.95 190 5.1 1174 1.4 0.04 0.03 0.04

Bass Lake 0.13 0.029 0.84 145 1002 23.8 3368 3.0 0.03 0.01 0.07

Lopez Lake 0.12 0.018 3.80 166 934 37.9 478 4.9 0.09 0.09 0.09

Palmdale Lake 0.11 0.007 1.12 30 230 6.0 2818 0.4 0.06 0.06 0.06

Antelope Lake 0.11 0.016 0.37 113 949 31.7 5005 4.1 0.05 0.05 0.05

Malibou Lake 0.09 0.023 2.68 44 38 4.7 724 0.7 0.09 0.11 0.07

Lake of the Pines 0.09 0.023 0.55 68 219 9.0 1511 2.4 0.18 0.14 0.19

Loch Lomond Reservoir 0.07 0.020 2.82 182 171 10.3 572 1.7

Sunbeam Lake 0.07 0.022 6.55 31 4.8 -34 3.3 0.01 0.01 0.01

Senator Wash Reservoir 0.07 0.025 12.98 84 383 13.9 210 2.8 0.02 0.01 0.03

Dixon Lake 0.06 0.016 4.30 116 61 3.4 1035 1.7 0.04 0.03 0.05

Lake Evans 0.05 0.009 1.56 12 28 1.4 783 1.1 0.07 0.06 0.07

Lincoln Park Lake 0.05 0.017 1.45 5 0.6 350 1.1 0.15 0.16 0.14

Lake Henshaw 0.03 0.005 1.39 123 1662 16.6 2689 1.6 0.01 0.01 0.01

Prado Lake 0.02 0.003 0.51 59 4.3 536 0.7 0.02 0.01 0.05

Caples Lake 0.107 0.56 71 601 11.1 7800 1.8 0.07 0.01 0.10

Gold Lake 0.060 0.92 484 8.6 6409 1.5 0.14 0.08 0.17

Castaic Lake 0.051 1.73 340 2267 46.5 1518 3.8 0.05 0.03 0.09

Lewiston Lake 73 675 31.2 1906 4.7 0.10 0.09 0.10

Lake

Lake Properties Sediment

Table4a. Continued.Arithmeticmeanconcentrationsinfish,sediment,andwater;andlakepropertiesforallofthelakesinthestatewidesurvey.Bassdataaremeansfor12individuals.Preyfishdataaremeansacrosstwoormorespecies.*-AverageofuncensoredvaluesbelowMDLs.**-AverageincludingbothdetectedvaluesanduncensoredvaluesbelowMDLs.

Total

Mercury,

Open

Water

(mg/kg

dw)

Largemou

th Bass

(350 mm

std size)

Mercury

(ug/g ww)

Prey Fish

Mercury

(ug/g ww)

Lake-

wide

Average

Total

Mercury

(ng/L)

Total

Mercury

(ng/L) -

Bank,

Near

bottom

Total

Mercury

(ng/L) -

Bank,

Near

surface

Total

Mercury

(ng/L) -

Open

Water,

Near

bottom

Total

Mercury

(ng/L) -

Open

Water,

Near

surface

Lake-

wide

Average

Methylm

ercury

(ng/L)

Methyl-

mercury

(ng/L) -

Bank,

Near

bottom

Methylm

ercury

(ng/L) -

Bank,

Near

surface

Methyl-

mercury

(ng/L) -

Open

Water,

Near

bottom

Methyl-

mercury

(ng/L) -

Open

Water,

Near

surface

Lake-

wide

Average

SO4

(mg/L)

SO4

(mg/L) -

Bank,

Near

bottom

SO4

(mg/L) -

Bank,

Near

surface

SO4

(mg/L) -

Open

Water,

Near

bottom

SO4

(mg/L) -

Open

Water,

Near

surface

Lake-

wide

Average

Chloro-

phyll a

(ug/L)

Lake-

wide

Average

DOC

(mg/L)

DOC

(mg/L) -

Bank,

Near

bottom

DOC

(mg/L) -

Bank,

Near

surface

0.24 Lake Merced 0.28 0.022 0.67 0.67 0.57 0.81 0.58 **0.05 0.07 0.05 **0.04 **0.04 7.5 7.6 7.7 7.4 7.6 40 7.7 7.7 8.1

0.11 Lake Gregory 0.25 0.029 0.98 0.65 0.46 1.91 0.48 **0.16 0.04 *0.02 0.40 0.05 2.5 3.1 3.0 1.4 3.0 < 24 6.0 6.3 6.1

0.04 Lake Jennings 0.25 0.059 0.18 0.15 0.27 0.19 0.14 *0.02 *0.01 *0.04 *0.02 *0.01 169.7 169.0 167.0 170.5 170.5 < 24 3.5 3.4 3.5

0.11 Legg Lake 0.18 0.012 0.87 0.88 0.57 1.16 0.56 **0.03 *0.04 *0.03 **0.03 *0.04 153.8 147.0 154.0 158.5 152.5 < 24 2.8 2.7 2.7

0.04 Castaic Lagoon 0.15 0.024 0.30 0.30 0.31 0.35 0.24 *0.02 *0.01 *0.03 *0.03 *0.01 98.4 100.0 103.0 98.8 95.1 < 24 3.7 3.8 4.0

0.07 Bass Lake 0.13 0.029 0.37 0.27 0.26 0.91 0.21 *0.01 *0.00 *0.00 *0.03 *0.00 0.2 0.2 0.2 0.4 0.2 < 24 2.4 2.4 2.6

0.09 Lopez Lake 0.12 0.018 0.61 0.61 **0.10 *0.02 0.05 0.25 *0.02 120.7 122.0 122.0 118.0 122.0 38 6.5 7.2 6.8

0.06 Palmdale Lake 0.11 0.007 0.37 0.37 0.36 0.35 0.37 *0.01 *0.01 *0.01 *0.01 *0.01 67.3 67.2 67.6 66.9 67.7 < 24 3.0 2.8 2.9

0.05 Antelope Lake 0.11 0.016 0.46 0.43 0.34 0.67 0.33 **0.15 0.53 *0.01 **0.17 *0.01 0.3 0.3 0.3 0.3 0.3 < 24 4.6 4.8 4.8

0.07 Malibou Lake 0.09 0.023 **0.14 *0.00 0.08 0.34 **0.04 841.3 866.0 848.0 821.0 846.0 68 7.5 7.5 7.4

0.19 Lake of the Pines 0.09 0.023 0.39 0.35 0.85 0.31 0.26 **0.02 *0.01 *0.00 *0.01 **0.05 5.5 5.3 5.3 5.3 5.7 < 24 3.1 3.2 4.0

Loch Lomond Reservoir 0.07 0.020 0.35 0.36 0.31 0.43 0.29 *0.01 *0.01 *0.00 *0.01 *0.01 72.5 76.8 77.7 68.8 71.4 < 24

0.01 Sunbeam Lake 0.07 0.022 0.33 0.28 0.29 0.39 0.32 **0.04 *0.02 *0.01 **0.07 *0.02 287.5 287.0 281.0 289.0 289.5 < 24 4.1 4.8 4.0

0.03 Senator Wash Reservoir 0.07 0.025 0.52 0.45 0.42 0.76 0.38 *0.02 *0.02 *0.01 *0.03 *0.02 280.7 261.0 267.0 300.5 277.5 < 24 3.1 3.1 3.2

0.05 Dixon Lake 0.06 0.016 0.29 0.15 0.14 0.60 0.11 **0.08 *0.00 *0.00 **0.22 *0.02 148.2 150.0 148.0 148.0 147.5 < 24 2.7 2.7 2.7

0.07 Lake Evans 0.05 0.009 0.70 0.84 0.62 0.74 0.63 *0.02 *0.02 *0.01 *0.03 *0.02 78.9 80.0 78.1 79.2 78.6 < 24

0.14 Lincoln Park Lake 0.05 0.017 0.91 0.96 0.96 0.96 0.80 **0.10 0.10 0.09 0.12 0.09 278.2 280.0 272.0 280.0 278.5 < 24 9.4 9.4

0.01 Lake Henshaw 0.03 0.005 1.36 1.51 1.13 1.51 1.25 **0.02 *0.02 *0.01 **0.04 *0.01 117.3 161.0 107.0 109.5 108.5 189 8.1 7.8 7.9

0.05 Prado Lake 0.02 0.003 0.44 0.47 0.40 0.52 0.36 *0.01 *0.01 *0.01 *0.00 *0.02 79.7 79.0 79.7 80.7 80.1 81 7.5 7.5 7.7

0.10 Caples Lake 0.107 0.50 0.57 0.46 0.57 0.40 *0.01 *0.01 *0.01 *0.02 *0.01 0.6 0.5 1.3 0.5 0.5 < 24 1.7 1.7 1.8

0.17 Gold Lake 0.060 0.45 0.94 0.31 0.41 0.30 **0.02 *0.01 *0.00 **0.04 *0.01 0.8 0.8 0.9 0.8 0.8 < 24 1.8 1.9 1.8

0.09 Castaic Lake 0.051 0.50 0.76 0.35 0.51 0.31 **0.01 **0.03 *0.00 *0.01 *0.01 52.3 50.8 53.3 53.6 51.8 < 24 2.3 2.3 2.3

0.10 Lewiston Lake 0.51 0.70 0.46 0.49 0.46 *0.01 *0.01 *0.00 *0.01 *0.01 1.3 1.3 1.3 1.3 1.3 < 24 1.3 1.4 1.3

Sediment

Lake

Fish Water

Table4b. Additionalinformationonlakepropertiesforthelakesincludedinthestatewidesurvey.

Lake

Largemouth Bass (350

mm std size) Mercury

(ug/g ww)

Prey Fish Mercury

(ug/g ww)Quagga

Invasion* WaterSource Fishstocked** Chl-adata***WaterLevelsMaintained?

Water Level Data (past ~5 or more years)

Lake Merced 0.28 0.022 NoWithinwatershed-exactsourcenotspecified

Rainbowtrout,annualstocking Yes,quarterly No

Lake Gregory 0.25 0.029 No StormwaterRainbowtrout,stockedbi-monthly

Yes,maintainedlowbyPalmdaleWaterDistrict

Lake Jennings 0.25 0.059 YesImported-StateWaterProjectandColoradoRiver

Rainbowtrout&Channelcatfish,weeklystocking Notmonitored

Yes,butdrawndownyearlyduringthedryseason

Legg Lake 0.18 0.012 No

Stormwaterrunoff,reclaimedwater,potablewater,post-treatmentSuperfundsitedischarge

Rainbowtrout,laketrout,andothers,monthlystocking

Yes,dataprovidedbyRB4

Yes,asneededtocreatespaceforstormwaterrunoff No specific reference

Castaic Lagoon 0.15 0.024 Yes,minor Imported;releasesfromCastaicLakeProbablynot;existingblackbassarefished

Yes,dataprovidedbyRB4 Possibly http://castaic.lakesonline.com/Level.asp

Bass Lake 0.13 0.029 NoSanJoaquinRiver,WillowCreektributary

Yes,rainbowtroutandfingerlingkokaneesalmonbyCDFW https://basslakeca.com/lake.html

Lopez Lake 0.12 0.018 No

Stormwaterrunoff,ArroyoGrandeCreek(servesasmunicipalwatersupply) Yes

Palmdale Lake 0.11 0.007 NoStateWaterProject,stormwater,Littlerockreservoir Yes,byCDFW(?)

Yes,maintainedbySanBernadinoCounty

Antelope Lake 0.11 0.016 NoStateWaterProject,throughtheUpperFeatherRiverandIndianCreek

Yes,brooktrout,eaglelaketrout,andrainbowtroutbyCDFW

ConstantflowmaintainedbelowAntelopeDam CDEC

Malibou Lake 0.09 0.023 No Stormwater

Hasbluegill,largemouthbass,catfishandcarp.Maybeprivatelystockedattimes.

Yes,dataprovidedbyRB4 No

Lake of the Pines 0.09 0.023 No (servesasmunicipalwatersupply)

Loch Lomond Reservoir 0.07 0.020 No NewellCreekYes,rainbowtroutinthesummerbyCDFW

Sunbeam Lake 0.07 0.022 NoCanalwater(All-Americancanal,possibly)

Yes,bassandtroutarestocked None

Yes,bySunbeamRVPark USGS streamgage

Senator Wash Reservoir 0.07 0.025 No ColoradoRiver No None YesUSGS streamgage on the Colorado River used as a proxy

Dixon Lake 0.06 0.016 YesImported(ColoradoRiverandStateWaterProjectblend)

Rainbowtrout&Channelcatfish Yes

Lake Evans 0.05 0.009 No

Primarilygroundwaterpumpedfromthreewells.SeasonalinflowfromSpringBrookWash

Catfishstockedonceayearthrough2015

Lincoln Park Lake 0.05 0.017 NoPotable(sourcenotspecifiedinTMDL);nostormwater Rainbowtrout

Yes,dataprovidedbyRB4;Algaecidesusedtocontrolalgae

Yes,maintainedwithpotablewater No specific reference

Lake Henshaw 0.03 0.005 NoSurfacewaterrunoff,pumpedgroundwaterstoragereservoir No

No,thereareannualdiversions

Prado Lake 0.02 0.003 No Recycledwater Yes,rainbowtroutbyCDFW

Table5. NonparametricSpearmancorrelationcoefficientsforpotentialexplanatoryvariables.***=p<0.001,**=p<0.01,*=p<0.05.

Chl

orop

hyll

a

Chl

orop

hyll

a, B

ank

Nea

r-bo

ttom

Chl

orop

hyll

a, B

ank

Nea

r-su

rface

Chl

orop

hyll

a, O

pen

Wat

er

Nea

r-bo

ttom

Chl

orop

hyll

a, O

pen

Wat

er

Nea

r-su

rface

DO

C

DO

C, B

ank

Nea

r-bo

ttom

DO

C, B

ank,

Nea

r-su

rface

DO

C, O

pen

Wat

er N

ear-

botto

m

DO

C, O

pen

Wat

er N

ear-

surfa

ce

THg,

Lar

gem

outh

Bas

s

THg,

Lar

gem

outh

Bas

s, 3

50

mm

std

MeH

g in

wat

er

MeH

g in

wat

er, B

ank

Nea

r-bo

ttom

MeH

g in

wat

er, B

ank

Nea

r-su

rface

MeH

g in

wat

er, O

pen

Wat

er

Nea

r-bo

ttom

MeH

g in

wat

er, O

pen

Wat

er

Nea

r-su

rface

MeH

g / C

hlor

ophy

ll a

MeH

g / C

hlor

ophy

ll a,

Ban

k N

ear-

botto

m

MeH

g / C

hlor

ophy

ll a,

Ban

k N

ear-

surfa

ce

MeH

g / C

hlor

ophy

ll a,

Ope

n W

ater

Nea

r-bo

ttom

MeH

g / C

hlor

ophy

ll a,

Ope

n W

ater

Nea

r-su

rface

THg,

Pre

y Fi

sh

Se,

Pre

y Fi

sh

SO

4

SO

4, B

ank

Nea

r-bo

ttom

SO

4, B

ank

Nea

r-su

rface

SO

4, O

pen

Wat

er N

ear-

botto

m

SO

4, O

pen

Wat

er N

ear-

surfa

ce

THg

in s

edim

ent

THg

in w

ater

THg

in w

ater

, Ban

k N

ear-

botto

m

THg

in w

ater

, Ban

k N

ear-

surfa

ce

THg

in w

ater

, Ope

n W

ater

Nea

r-bo

ttom

THg

in w

ater

, Ope

n W

ater

Nea

r-su

rface

Dam

Hei

ght

Lake

Sur

face

Are

a

Lake

Per

imet

er

Lake

Ele

vatio

n

Lake

Sha

pe In

dex

Con

duct

ivity

Dis

solv

ed O

xyge

n, N

ear-

botto

m

Chlorophyll aChlorophyll a, Bank Near-bottom 1.00***Chlorophyll a, Bank Near-surface 0.99*** 0.99***Chlorophyll a, Open Water Near-bottom 0.91*** 0.89*** 0.86***Chlorophyll a, Open Water Near-surface 1.00*** 1.00*** 0.99*** 0.89***DOC 0.65** 0.65** 0.64** 0.60** 0.65** DOC, Bank Near-bottom 0.65** 0.65** 0.64** 0.60** 0.65** 1.00***DOC, Bank, Near-surface 0.75*** 0.74*** 0.74*** 0.69*** 0.74*** 0.99*** 0.99***DOC, Open Water Near-bottom 0.65** 0.65** 0.65** 0.60** 0.65** 0.99*** 0.98*** 0.96***DOC, Open Water Near-surface 0.65** 0.64** 0.64** 0.60** 0.64** 0.99*** 0.99*** 0.98*** 0.99***THg, Largemouth Bass -0.23 -0.25 -0.21 -0.24 -0.25 -0.25 -0.24 -0.07 -0.30 -0.24THg, Largemouth Bass, 350 mm std -0.20 -0.21 -0.16 -0.24 -0.21 -0.23 -0.23 -0.08 -0.25 -0.19 0.93***MeHg in water 0.22 0.23 0.27 0.11 0.23 0.66** 0.65** 0.60** 0.65** 0.67*** 0.14 0.23MeHg in water, Bank Near-bottom 0.05 0.04 0.03 0.05 0.04 0.45* 0.43 0.36 0.39 0.44* -0.01 0.08 0.64***MeHg in water, Bank Near-surface 0.37 0.37 0.40 0.28 0.37 0.73*** 0.72*** 0.65** 0.72*** 0.74*** 0.29 0.37 0.81*** 0.49* MeHg in water, Open Water Near-bottom 0.20 0.21 0.26 0.08 0.21 0.44* 0.43* 0.39 0.50* 0.46* 0.00 0.17 0.72*** 0.26 0.50* MeHg in water, Open Water Near-surface 0.23 0.22 0.23 0.21 0.22 0.57** 0.59** 0.56* 0.53* 0.55** 0.04 -0.02 0.72*** 0.35 0.53** 0.38MeHg / Chlorophyll a -0.28 -0.28 -0.25 -0.37 -0.28 0.25 0.25 0.15 0.22 0.25 0.21 0.27 0.83*** 0.63** 0.56** 0.55** 0.60** MeHg / Chlorophyll a, Bank Near-bottom -0.45* -0.47* -0.46* -0.39 -0.47* 0.07 0.06 -0.05 0.03 0.07 0.28 0.33 0.53** 0.81*** 0.35 0.17 0.29 0.78***MeHg / Chlorophyll a, Bank Near-surface -0.29 -0.29 -0.26 -0.30 -0.29 0.27 0.26 0.12 0.25 0.27 0.46* 0.51* 0.67*** 0.46* 0.77*** 0.35 0.39 0.76*** 0.67***MeHg / Chlorophyll a, Open Water Near-bottom -0.10 -0.09 -0.03 -0.24 -0.09 0.20 0.19 0.11 0.25 0.21 0.11 0.28 0.63** 0.13 0.42* 0.90*** 0.32 0.64*** 0.27 0.47* MeHg / Chlorophyll a, Open Water Near-surface -0.39 -0.41 -0.39 -0.37 -0.41 0.09 0.11 0.01 0.06 0.09 0.26 0.20 0.55** 0.35 0.29 0.24 0.76*** 0.78*** 0.62** 0.57** 0.35THg, Prey Fish -0.38 -0.39 -0.35 -0.37 -0.39 -0.52* -0.52* -0.54* -0.53* -0.53* 0.63** 0.55* -0.06 -0.14 -0.03 -0.03 -0.23 0.08 0.17 0.27 0.13 0.04Se, Prey Fish -0.18 -0.16 -0.11 -0.31 -0.16 -0.08 -0.08 -0.18 -0.02 -0.06 -0.06 -0.14 0.05 -0.26 0.10 0.09 -0.03 0.07 -0.19 0.20 0.16 0.02 0.12SO4 0.24 0.25 0.27 0.17 0.25 0.44* 0.44* 0.34 0.48* 0.45* -0.25 -0.30 0.42* 0.02 0.52* 0.22 0.48* 0.24 -0.10 0.35 0.16 0.22 -0.23 0.76***SO4, Bank Near-bottom 0.27 0.28 0.29 0.22 0.28 0.49* 0.50* 0.38 0.54* 0.51* -0.32 -0.37 0.42* 0.03 0.50* 0.24 0.47* 0.20 -0.12 0.31 0.14 0.19 -0.25 0.74*** 0.99***SO4, Bank Near-surface 0.24 0.25 0.27 0.17 0.25 0.45* 0.46* 0.33 0.49* 0.47* -0.26 -0.31 0.42* 0.03 0.53** 0.22 0.48* 0.24 -0.09 0.36 0.16 0.22 -0.24 0.74*** 1.00*** 0.99***SO4, Open Water Near-bottom 0.24 0.25 0.27 0.17 0.25 0.42 0.43 0.32 0.46* 0.43* -0.25 -0.30 0.40 0.00 0.51* 0.21 0.47* 0.22 -0.12 0.34 0.15 0.21 -0.21 0.77*** 1.00*** 0.99*** 1.00***SO4, Open Water Near-surface 0.24 0.25 0.27 0.17 0.25 0.45* 0.46* 0.34 0.49* 0.47* -0.26 -0.31 0.42* 0.03 0.53** 0.23 0.48* 0.24 -0.10 0.36 0.17 0.22 -0.24 0.75*** 1.00*** 0.99*** 1.00*** 1.00***THg in sediment -0.13 -0.14 -0.10 -0.18 -0.14 -0.07 -0.05 -0.12 -0.09 -0.05 0.48* 0.39 0.37 0.14 0.11 0.15 0.47* 0.42 0.34 0.17 0.26 0.56** 0.15 -0.36 -0.25 -0.27 -0.24 -0.25 -0.23THg in water 0.36 0.36 0.37 0.31 0.36 0.37 0.35 0.27 0.35 0.38 -0.21 -0.16 0.55** 0.67*** 0.34 0.28 0.43* 0.34 0.36 0.09 0.08 0.20 -0.28 -0.30 0.00 0.03 0.02 0.00 0.01 0.37THg in water, Bank Near-bottom 0.31 0.31 0.31 0.31 0.31 0.12 0.10 -0.04 0.10 0.14 -0.26 -0.25 0.35 0.53* 0.11 0.10 0.24 0.15 0.26 -0.09 -0.08 0.07 -0.19 -0.29 -0.06 -0.03 -0.06 -0.06 -0.05 0.39 0.88***THg in water, Bank Near-surface 0.37 0.37 0.37 0.37 0.37 0.32 0.33 0.27 0.26 0.32 -0.19 -0.23 0.41 0.51* 0.24 -0.06 0.53* 0.20 0.25 0.00 -0.27 0.31 -0.31 -0.40 0.01 0.04 0.03 0.01 0.02 0.46* 0.85*** 0.74***THg in water, Open Water Near-bottom 0.30 0.30 0.30 0.30 0.30 0.34 0.31 0.23 0.32 0.31 -0.12 -0.05 0.45* 0.53* 0.29 0.56** 0.29 0.28 0.29 0.08 0.36 0.11 -0.25 -0.22 -0.02 -0.01 -0.01 0.00 -0.02 0.07 0.73*** 0.53* 0.43THg in water, Open Water Near-surface 0.44* 0.45* 0.46* 0.35 0.45* 0.48* 0.46* 0.38 0.46* 0.49* -0.28 -0.21 0.57** 0.62** 0.43* 0.29 0.46* 0.33 0.28 0.12 0.08 0.19 -0.41 -0.20 0.13 0.17 0.15 0.13 0.14 0.28 0.95*** 0.81*** 0.84*** 0.65** Dam Height -0.05 -0.02 0.02 -0.19 -0.02 -0.23 -0.25 -0.17 -0.19 -0.23 0.15 0.10 -0.27 -0.34 -0.32 0.08 -0.51* -0.23 -0.36 -0.32 0.04 -0.40 0.27 0.24 -0.19 -0.16 -0.20 -0.17 -0.20 -0.20 -0.27 -0.40 -0.38 -0.05 -0.29Lake Surface Area 0.19 0.20 0.22 0.11 0.20 -0.10 -0.14 0.06 -0.12 -0.10 0.11 0.19 -0.26 0.00 -0.24 -0.07 -0.54* -0.35 -0.18 -0.36 -0.23 -0.48* 0.09 -0.23 -0.48* -0.45 -0.51* -0.46* -0.51* -0.27 -0.07 -0.15 -0.08 0.00 -0.05 0.54* Lake Perimeter 0.15 0.17 0.20 0.00 0.17 -0.09 -0.11 0.09 -0.12 -0.10 0.15 0.17 -0.24 -0.06 -0.17 -0.11 -0.57* -0.28 -0.20 -0.29 -0.21 -0.51* 0.18 -0.02 -0.32 -0.31 -0.34 -0.31 -0.34 -0.27 -0.18 -0.29 -0.21 -0.16 -0.15 0.63** 0.91***Lake Elevation -0.16 -0.15 -0.15 -0.12 -0.15 -0.21 -0.23 -0.14 -0.14 -0.17 -0.01 0.09 -0.32 -0.20 -0.44 0.08 -0.43 -0.30 -0.16 -0.33 0.05 -0.33 0.03 -0.43 -0.64** -0.58** -0.64** -0.64** -0.64** -0.04 -0.10 -0.15 -0.09 0.03 -0.25 0.41 0.46* 0.27Lake Shape Index -0.30 -0.27 -0.23 -0.45 -0.27 -0.30 -0.30 -0.20 -0.38 -0.36 0.22 0.25 0.12 0.23 -0.05 0.20 -0.14 0.39 0.27 0.14 0.25 0.08 0.38 0.22 -0.08 -0.13 -0.10 -0.09 -0.10 -0.12 -0.20 -0.41 -0.35 0.00 -0.26 0.44 0.38 0.56* -0.03Conductivity 0.39 0.33 0.33 0.48 0.33 0.37 0.37 0.14 0.38 0.37 -0.25 -0.37 0.15 0.00 0.70* 0.03 0.32 0.15 -0.08 0.35 0.05 -0.02 -0.12 0.20 0.82** 0.78* 0.82** 0.82** 0.82** 0.22 0.29 0.64 0.61 0.18 0.40 -0.43 -0.70* -0.50 -0.68* -0.25Dissolved Oxygen, Near-bottom -0.58 -0.64 -0.64 -0.30 -0.64 -0.27 -0.27 -0.64 -0.35 -0.27 -0.30 -0.23 -0.33 0.17 -0.02 -0.73* -0.02 0.00 0.32 0.45 -0.65 0.35 -0.62 -0.15 0.32 0.25 0.32 0.32 0.32 -0.05 0.17 0.43 0.25 -0.07 -0.02 -0.72* -0.52 -0.53 -0.23 -0.32 0.35pH -0.21 -0.25 -0.25 -0.09 -0.25 0.32 0.32 0.02 0.25 0.32 -0.31 -0.21 0.01 0.41 0.21 -0.64 -0.08 -0.08 0.38 0.20 -0.71* 0.16 -0.29 -0.25 -0.09 -0.07 -0.09 -0.09 -0.09 0.09 0.00 0.22 0.33 -0.52 0.32 -0.51 0.17 0.13 -0.26 -0.37 0.03 0.43

Mixed-Effects Models

!  Dependent Variable: Largemouth Bass, 350 mm size standardized (log transformed)

!  Random Variables1.  Lake – account for spatial autocorrelation2.  Prey Species / Lake (nested random effect)

!  Fixed Variables: various additive combinations of:•  Prey fish Hg•  Water parameter (MeHg)•  Sediment parameter (Total Mercury)•  Lake property parameter (Lake Shape Index)

Table6. Linearmixed-effectsmodelcandidatesetfor350mmlargemouthbassmercury(dependentvariable).Preyfishspecies/lakewasincludedinthemodelasanestedrandomeffect.P-valueshighlightedinredindicatesignificantfactorsineachmodel.Modelshighlightedingreywerenotconsideredbetterthanthenullmodel.

Factorp-values

FixedEffects AICc InterceptTHgPreyFish MeHgwater THgsediment

LakeShapeIndex

Null 3008.671 THgPreyFish+LakeShapeIndex 2993.053 0 0.0001 0.15THgPreyFish 2993.178 0 0.0001 THgPreyFish+THgsediment+LakeShapeIndex 2994.894 0 0.0001 0.69 0.15THgPreyFish+THgsediment 2995.039 0 0.0001 0.71THgPreyFish+MeHgwater+LakeShapeIndex 2995.043 0 0.0001 0.92 0.15THgPreyFish+MeHgwater 2995.168 0 0.0001 0.92THgPreyFish+MeHgwater+THgsediment+LakeShapeIndex 2996.883 0 0.0001 0.92 0.69 0.15THgPreyFish+MeHgwater+THgsediment 2997.025 0 0.0001 0.01 0.71 LakeShapeIndex 3007.033 0 0.05THgsediment+LakeShapeIndex 3008.968 0 0.8 0.05MeHgwater+LakeShapeIndex 3009.03 0 0.95 0.05THgsediment 3010.600 0 0.79MeHgwater 3010.666 0 0.95MeHgwater+THgsediment+LakeShapeIndex 3010.964 0 0.95 0.8 0.05

!  Mystery remains unsolved!  Clear relationship with prey fish!  Lake shape also an influence!  Positive association of bank aqueous MeHg/Chl-a and

350 mm bass Hg!  Negative association of DOC and prey fish Hg!  Analysis handicapped by

•  Limited range in bass mercury•  Detection limit and data issues

!  Approaches to solving the mystery•  Expanding the empirical dataset•  Intensive process studies at selected lakes

MQ2: Why do some lakes have relatively low concentrations of methylmercury in sport fish?

!  Approaches to solving the mystery•  Expanding the empirical dataset

!  More lakes, wider range of bass Hg

!  Complete and quantitative datasets

!  Spatially and temporally representative data

!  Solid information on lake and watershed attributes

•  Intensive process studies at selected lakes

MQ2: Why do some lakes have relatively low concentrations of methylmercury in sport fish?

MQ3: Did the 2007-8 survey accurately characterize the status of lakes in which only rainbow trout were collected?

!  Minimally addressed!  Would require greater effort per lake!  Small dataset provides strong indication that

rainbow trout do not indicate general status of mercury in the food web

!  Significant information gap!  Prey fish a useful indicator for trout lakes

Next Steps

1.  Written corrections by Feb 202.  Finalize technical report - March3.  Draft a fact sheet? - March?4.  BOG review of fact sheet5.  Finalize fact sheet

!  Desired outcome: Obtain input on the plan and timeline for reporting the data and posting it to CEDEN and the Safe to Eat Portal.

2017

!  Sport fish•  Focus on bass and mercury•  PCBs and OCs in bottom-feeder in

selected lakes (20% for PCBs)•  New: Selenium in composites of all

species!  Prey fish•  Mercury and selenium (New) in

composites

Table1. Panel 2, 2017 BOG Fish Collection Summary

Region Waterbody Sport fish Prey spp

Black Bass Spp

Common Carp Bluegill Redear Green

Sunfish Catfish

Spp Crappie Brown Bullhead Other Bass

Spp Bluegill Threadfin

shad Silverside Green sunfish other

1 Iron Gate Reservoir 11 10 10 10 30

1 Pillsbury, Lake 22 20 20

2

Upper San Leandro

Reservoir 11 10 10 10 10 10

2 San Pablo Reservoir 11 10 10 10

2 Nicasio Reservoir 11 7 10 10 10

2 Coyote Lake 11 10 10 10 10

3 Cachuma, Lake 22 10 20 20

3 Pinto Lake 11 6 5 10 10

3 N Reservoir 11 10 10

3 Lopez Lake 11 10 10 10

3 Santa Margarita Lake 11 10 10 10 10

4 Crystal Lake

4 Wilderness Park Lake 4 9 10 10

4 Magic Johnson Lakes 11 10 10 10 10

4 Alondra Park Lake 11 10 10 10 7

4 Elizabeth Lake

5 New Hogan Lake 33 30 30

5 Whiskeytown Lake 33 30 30

5 Natomas, Lake 11 10 10 10 10 10 10 10

5 Isabella Lake 22 4 20 20 20

5

Mile Long Pond (One Mile

Lake) 11 10 10 10 10 10

5 Black Butte Lake 11 20 10 10

5 Davis Creek Reservoir 11 10 10 10

5 Los Banos Reservoir 11 10 10 10 10

5 Pardee Reservoir 22 20 10

5 Webb, Lake 11 10 10 10 10

5 Mountain Meadows Reservoir

5 Collins Lake 11 10 3 10 10 10 10

5 Lake of the Pines 11 10 10 10 10

5 Hensley Lake 19 10 6 11 1 8 20 20 21

6 Palmdale Lake 11 16 8 12 11 10 10 10 10 10

6 Silverwood Lake 11 3 10 9 6 5 10 10 11

7 Ferguson Lake 11 10

8 Elsinore, Lake 2

8 Evans Lake 8

9 Skinner Reservoir 11 10 7 10 1

9 Hodges, Lake 11 10 10 10

9 Jennings, Lake 11 10 10 10

9 Laguna Niguel Park Lake (Sulphur Ck Res) 11 10 10 10

9 Sutherland, Lake 11 10 10 10 10

Timeline for Releasing the 2017 Data!  Sampling – Completed in September 2017!  Analysis – Completed in xx!  State Board QA review and upload – Upload completed

xx, QA report completed xx!  SFEI review and data “report” generation – xx – issue to

resolve regarding data flow!  BOG review – xx!  Upload to CEDEN and Portal – xx

Item 7: General Timeline for 2018!  Clean Lakes – final tech report in March – fact

sheet?!  2015 Bass Lakes – final data report in March!  2016 Lakes – final data report and posting in

March!  2017 Bass Lakes – final data report in xx !  2018 Bight – intercalibration in April (June) –

sampling in May-Oct – sample distribution begins in June

!  Water Boards Science Symposium in June