U.S. Department of the Interior

U.S. Geological Survey

Open File Report 2011–1297

Prepared in cooperation with the National Park Service, Whiskeytown National Recreation 

Area and the Burned Area Response Program

Concentrations of Mercury and other Metals in 

Black Bass (Micropterus spp.) from Whiskeytown Lake, 

Shasta County, California, 2005

Concentrations of Mercury and other 

Metals in Black Bass (Micropterus spp.) 

from Whiskeytown Lake, Shasta County, 

California, 2005

By Jason T. May, Roger L. Hothem, Marissa L. Bauer, and Larry R. Brown

Prepared in cooperation with the National Park Service, Whiskeytown National 

Recreation Area and the Burned Area Response Program

Open-File Report 2011–1297 

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2012

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Suggested citation:

May, J.T., Hothem, R.L., Bauer, M.L., and Brown, L.R., 2012, Concentrations of mercury and other metals in black bass 

(Micropterus spp.) from Whiskeytown Lake, Shasta County, California, 2005: U.S. Geological Survey, Open-File 

Report 2011–1297, 16 p. 
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Purpose and Scope .......................................................................................................................................5

Field Methods and Sample Preservation Techniques .............................................................................5

Laboratory Methods of Chemical Analysis ...............................................................................................5

Quality Assurance and Quality Control ......................................................................................................6

Results and Discussion.................................................................................................................................7

Acknowledgements.....................................................................................................................................15

References....................................................................................................................................................15

Figures

1. Map showing fish sampling locations within Whiskeytown Lake, Shasta County,

California ........................................................................................................................................2

2. Graph showing mercury concentration for all bass (Micropterus spp.) samples

collected from Whiskeytown Lake, California, 2005, in relation to total length ...............14

3. Correlation plot of mercury concentration in fillet samples in relation to

whole-body samples for for all bass (Micropterus spp.) samples collected from

Whiskeytown Lake, California, 2005 ........................................................................................15

Tables

1. Sites within Whiskeytown Lake, California, sampled during 2005 .......................................3

2. Total mercury concentrations in fillet and whole-body samples of largemouth

bass (Micropterus salmoides) and spotted bass (M. punctulatus) collected from

Whiskeytown Lake, California, June 7–9, 2005........................................................................3

3. Concentrations of selected metals and sulfur in whole-body samples of

largemouth bass (Micropterus salmoides) and spotted bass (Micropterus

punctulatus) collected from Whiskeytown Lake, California, June 2005..............................8
iv

Multiply By To obtain

Length

millimeter (mm) 0.03937 inch (in)

Mass

microgram (μg) 0.000000035 ounce, avoirdupois (oz)

milligram (mg) 0.000035 ounce, avoirdupois (oz)

gram (g) ounce, avoirdupois (oz)

kilogram (kg) 2.205 pound avoirdupois (lb)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F=(1.8×°C)+32

Horizontal coordinate information is referenced to the “North American Datum of 1983 (NAD 

83)”

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) 

or micrograms per liter (μg/L).

Conversion Factors, Horizontal Datum, Acronym and 

Abbreviations, and Chemical Elements

Conversion Factors

Si to Inch/Pound

Acronyms, Abbreviations, and Chemical Notation

(additional information given in parentheses)

CRV certified reference value

CVAAS cold vapor atomic-absorption spectroscopy

CVAFS cold vapor atomic-fluorescence spectrometry

dw dry weight

ICP-MS coupled plasma–mass spectroscopy

ICP-OES inductively coupled plasma–optical emission spectroscopy

LOD limit of detection

MDL method detection limit

MOhm megaohm

NPS National Parks Service

NRA National Recreation Area

NRCC National Research Council of Canada

OEHHA Office of Environmental Health Hazard Assessment

QA quality assurance

QC quality control
v

RPD relative percent difference

SRM standard reference material

SV screening value

TERL Trace Element Research Laboratory (College Station, Texas)

USEPA U.S. Environmental Protection Agency

USGS U.S. Geological Survey

WHIS Whiskeytown National Recreation Area

v/v The formula for volume percent (v/v) is: [Volume of solute (mL)/

Volume of solution (mL)] x 100

ww wet weight

HgT total mercury

Hg2+ divalent mercury

ppm part per million (μg/g)

spp. species (plural)

WHIS Whiskeytown National Recreation Area

Chemical Elements

Al aluminum

As arsenic

Ag silver

B boron

Ba barium

Be beryllium

Ca calcium

Cd cadmium

Co cobalt

Cr chromium

Cu copper

Fe iron

Hg mercury

K potassium

Mg magnesium

Mn manganese

Mo molybdenum

Na sodium

Ni nickel

P phosphorus

Pb lead

S sulfur

Se selenium
vi

Sr strontium

Ti titanium

V vanadium

Zn zinc

Chemical Compounds, Isotopes,and 

other Chemical Notation

CH3 methyl radical

CH4 methane

CH2

Cl2 methylene chloride

CuSO4 copper sulfate

Fe(II) ferrous (divalent) iron

Fe(III) ferric (trivalent) iron

HCl hydrochloric acid

HF hydrofluoric acid

HNO3 nitric acid

Hg0 elemental mercury

Hg+ mercurous ion

Hg2+ mercuric ion

Hg(II) divalent mercury

HgCl2 mercuric chloride

HgT total mercury

203Hg(II) mercury-203 radiotracer divalent inorganic mercury

KBr potassium bromide

MeHg methylmercury (monomethylmercury)

N2 nitrogen gas

NaBEt4 sodium tetra-ethyl borate

O2 oxygen gas

SiO2 silicon dioxide, or silica

SnCl2 stannous chloride
Abstract

This report presents the results of a reconnaissance study 

conducted by the U.S. Geological Survey (USGS) to determine mercury (Hg) and other selected metal concentrations 

in Black bass (Micropterus spp.) from Whiskeytown Lake, 

Shasta County, California. Total mercury concentrations were 

determined by cold-vapor atomic absorption spectroscopy 

(CVAAS) in fillets and whole bodies of each sampled fish. 

Selected metals scans were performed on whole bodies (less 

the fillets) by inductively coupled plasma–mass spectroscopy 

(ICP-MS) and inductively coupled plasma–optical emission 

spectroscopy (ICP-OES). Mercury concentrations in fillet samples ranged from 0.06 to 0.52 micrograms per gram 

(μg/g) wet weight (ww). Total mercury (HgT) in the same fish 

whole-body samples ranged from 0.04 to 0.37 (μg/g, ww). 

Mercury concentrations in 17 percent of “legal catch size” 

(≥305 millimeters in length) were above the U.S. Environmental Protection Agency water-quality criterion for the protection 

of human health of 0.30 μg/g (ww). These data will serve as 

a baseline for future monitoring efforts within Whiskeytown 

Lake.

Introduction

Historic gold mining and naturally occurring mercury 

from geothermal sources has left many areas of California 

subject to mercury contamination. (California Department of 

Conservation, 2000; Alpers and others, 2005). The KlamathTrinity Mountains Region, specifically Trinity Lake and the 

upstream watershed, have previously documented elevated 

levels of mercury in resident sport fish (May and others, 

2005). The highest density historical mine sites within the 

Clear Creek Watershed occur in the upper Clear Creek area, 

and are likely sources of contamination to the local environment and Whiskeytown Lake (fig. 1; Moore and Hughes, 

2003). Run-off from abandoned mine lands has resulted in 

elevated levels of metals in the stream sediments (Moore 

and Hughes, 2003). Pristine water quality was identified by 

the Whiskeytown National Recreation Area (WHIS) and the 

National Parks Service (NPS) as WHIS’s Government Performance Results Act Goal Ia4 in their General Management 

Plan (National Parks Service, 1999). Whiskeytown Lake also 

serves as the domestic water supply for several nearby cities 

including Redding and Anderson. Additionally, the lake stores 

water for the Central Valley Project and functions as a major 

recreation area in Northern California, providing recreation 

for 700,000 visitors annually. Sport fishing is a popular recreational activity at Whiskeytown Lake and its tributaries. The 

lake supports recreational fishing for several species including 

two black bass species, largemouth bass (Micropterus salmoides) and spotted bass (M. punctulatus), which were collected 

as part of this reconnaissance effort. These lake fish samples 

are part of an ongoing effort that was begun in 2002 to characterize and monitor mercury and other metals ‘hot spots’ in the 

Upper Clear Creek watershed and WHIS.

During 2005, the U.S. Geological Survey (USGS) conducted a reconnaissance investigation in cooperation with the 

WHIS to assess mercury contamination associated with historical mining in the Clear Creek watershed. During this study, 

the USGS collected 63 black bass (44 largemouth bass and 19 

spotted bass) from three locations within Whiskeytown Lake: 

Clear Creek, Brandy Creek, and Whiskey Creek arms (fig. 1; 

tables 1 and 2). Mercury levels were determined in boneless/

skinless fillet tissue of each fish and the remaining whole-body 

sample of the same fish. Additional trace-metal analyses were 

also done on the remaining whole body. 

Concentrations of Mercury and other Metals in 

Black Bass (Micropterus spp.) from Whiskeytown Lake, 

Shasta County, California, 2005

By Jason T. May1, Roger L. Hothem2, Marissa L. Bauer1, and Larry R. Brown1

1

U.S. Geological Survey, California Water Science Center

2

U.S. Geological Survey, Western Ecological Research Center
2 Concentrations of mercury and other metals in black bass, Whiskeytown Lake, Shasta County, California, 2005

Whiskeytown National

Recreation Area

Extent of sampling areas

EXPLANATION

Gold mine, production and prospect

Map Source: MAS/MILS (Minerals Availability System/Minerals 

Information Location System) database compiled by U.S. Bureau of 

Mines, now archived by USGS

Upper Clear Creek

Clear Creek Arm Whiskey Creek Arm

Whiskeytown

Lake

0

0 1 2

1 2 Miles

Kilometers

Brandy/Boulder Creek Area

CALIFORNIA

Area of

 map

Pacific Ocean

San

Francisco

Figure 1. Fish sampling locations within Whiskeytown Lake, Shasta County, California.
 3

Table 1. Sites within Whiskeytown Lake, California, sampled during 2005.

[USGS, U.S. Geological Survey; °, degree; ʹ, minutes; N, north; W, west]

Official site name

Short 

name 

code

USGS site code

Range of collection areas

Upper 

latitude

Upper 

longitude

Lower 

latitude

Lower 

longitude

Whiskeytown Lake at Brandy Creek 

Arm near Whiskeytown, California

LKBB 403710122341501 40° 37.544' N 122° 35.046' W 40° 36.971' N 122° 33.469' W

Whiskeytown Lake at Clear Creek 

Arm near Whiskeytown, California

LKCC 403854122354801 40° 38.836' N 122° 36.232ʹ W 40° 38.806' N 122° 35.394' W

Whiskeytown Lake at Whiskey Creek 

Arm near Whiskeytown, California

LKWC 403859122332301 40° 39.174' N 122° 33.393' W 40° 38.875' N 122° 33.358' W

Table 2. Total mercury concentrations in fillet and whole-body samples of largemouth bass (Micropterus salmoides) and spotted bass 

(M. punctulatus) collected from Whiskeytown Lake, California, June 7–9, 2005. —Continued

[LKBB, Brandy/Boulder Creek area; LKCC, Clear Creek arm; LKWC, Whiskey Creek arm; LMBA, largemouth bass; SPBA, spotted bass; HgT, total mercury; 

g, gram; μg; microgram; mm, millimeter; wt., weight]

Site Species

Total 

length 

(mm)

Fillet code

Fillet 

sample 

mass 

(g)

Fillet HgT 

(μg/g,

wet wt.)

Fillet 

moisture 

(percent)

Whole-body 

code

Whole 

body 

sample 

mass (g)

Whole 

body HgT 

(μg/g, 

wet wt.)

Whole 

body 

moisture 

(percent)

LKBB LMBA 360 LKBB-060705-001F 63.7 0.119 81.8 LKBB-060705-001W 644.1 0.088 76.7

LKBB LMBA 382 LKBB-060705-002F 76.7 0.157 82.6 LKBB-060705-002W 684.0 0.108 77.6

LKBB LMBA 403 LKBB-060705-003F 114.5 0.343 80.4 LKBB-060705-003W 878.6 0.219 73.3

LKBB LMBA 345 LKBB-060705-006F 47.0 0.137 81.9 LKBB-060705-006W 474.3 0.083 76.8

LKBB LMBA 325 LKBB-060705-007F 62.3 0.214 81.4 LKBB-060705-007W 405.4 0.146 76.6

LKBB LMBA 330 LKBB-060705-008F 53.5 0.198 81.3 LKBB-060705-008W 432.1 0.123 75.4

LKBB LMBA 315 LKBB-060705-009F 43.7 0.169 81.7 LKBB-060705-009W 279.6 0.132 77.1

LKBB LMBA 318 LKBB-060705-011F 34.8 0.084 81.7 LKBB-060705-011W 390.2 0.052 77.4

LKBB LMBA 210 LKBB-060705-022F 7.8 0.096 81.3 LKBB-060705-022W 109.8 0.073 76.4

LKBB LMBA 180 LKBB-060705-023F 10.8 0.069 81.7 LKBB-060705-023W 62.0 0.054 76.8

LKBB LMBA 176 LKBB-060705-025F 4.8 0.135 82.9 LKBB-060705-025W 48.2 0.089 76.6

LKBB SPBA 385 LKBB-060705-005F 76.1 0.233 79.7 LKBB-060705-005W 708.6 0.167 73.1

LKBB SPBA 327 LKBB-060705-012F 28.5 0.209 82 LKBB-060705-012W 334.1 0.173 76.3

LKBB SPBA 293 LKBB-060705-013F 15.7 0.091 81.1 LKBB-060705-013W 261.2 0.069 75.5

LKBB SPBA 311 LKBB-060705-014F 28.1 0.267 80.9 LKBB-060705-014W 337.7 0.192 76.5

LKBB SPBA 249 LKBB-060705-017F 23.7 0.104 79.5 LKBB-060705-017W 152.2 0.073 75.6

LKBB SPBA 238 LKBB-060705-018F 18.6 0.118 79.8 LKBB-060705-018W 148.4 0.085 74.3

LKBB SPBA 235 LKBB-060705-019F 12.7 0.148 81.6 LKBB-060705-019W 98.3 0.11 75.9

LKBB SPBA 212 LKBB-060705-020F 13.0 0.096 79.3 LKBB-060705-020W 82.6 0.062 73.8

LKBB SPBA 173 LKBB-060705-026F 6.1 0.092 82.4 LKBB-060705-026W 44.8 0.064 77.1

LKBB SPBA 145 LKBB-060705-027F 3.3 0.074 81.4 LKBB-060705-027W 26.9 0.048 77.0

LKCC LMBA 443 LKCC-060805-001F 93.3 0.469 81.3 LKCC-060805-001W 1,056.10 0.258 74.7

LKCC LMBA 385 LKCC-060805-002F 73.3 0.252 80.5 LKCC-060805-002W 660.1 0.138 74.9

LKCC LMBA 370 LKCC-060805-003F 77.5 0.240 81.1 LKCC-060805-003W 699.5 0.134 75.7

LKCC LMBA 370 LKCC-060805-004F 68.4 0.21 80.7 LKCC-060805-004W 653.2 0.127 75.5

Table 2. Total mercury concentrations in fillet and whole-body samples of largemouth bass (Micropterus salmoides) and spotted 

bass (M. punctulatus) collected from Whiskeytown Lake, California, June 7–9, 2005. 

[LKBB, Brandy/Boulder Creek area; LKCC, Clear Creek arm; LKWC, Whiskey Creek arm; LMBA, largemouth bass; SPBA, spotted bass; HgT, total mercury; g, gram; μg; microgram; mm, millimeter; wt., weight]
4 Concentrations of mercury and other metals in black bass, Whiskeytown Lake, Shasta County, California, 2005

Table 2. Total mercury concentrations in fillet and whole-body samples of largemouth bass (Micropterus salmoides) and spotted bass 

(M. punctulatus) collected from Whiskeytown Lake, California, June 7–9, 2005. —Continued

[LKBB, Brandy/Boulder Creek area; LKCC, Clear Creek arm; LKWC, Whiskey Creek arm; LMBA, largemouth bass; SPBA, spotted bass; HgT, total mercury; 

g, gram; μg; microgram; mm, millimeter; wt., weight]

Site Species

Total 

length 

(mm)

Fillet code

Fillet 

sample 

mass 

(g)

Fillet HgT 

(μg/g,

wet wt.)

Fillet 

moisture 

(percent)

Whole-body 

code

Whole 

body 

sample 

mass (g)

Whole 

body HgT 

(μg/g, 

wet wt.)

Whole 

body 

moisture 

(percent)

LKCC LMBA 345 LKCC-060805-006F 30.5 0.201 82.2 LKCC-060805-006W 487.8 0.15 76.0

LKCC LMBA 273 LKCC-060805-011F 19.6 0.115 80.4 LKCC-060805-011W 267.1 0.088 78.3

LKCC LMBA 223 LKCC-060805-012F 15.0 0.064 80.6 LKCC-060805-012W 125.8 0.045 75.2

LKCC LMBA 248 LKCC-060805-013F 15.2 0.107 80.2 LKCC-060805-013W 174.9 0.08 75.9

LKCC LMBA 260 LKCC-060805-014F 11.8 0.095 80.2 LKCC-060805-014W 213.3 0.072 79.1

LKCC LMBA 200 LKCC-060805-015F 11.7 0.074 80.9 LKCC-060805-015W 96.1 0.054 76.9

LKCC LMBA 195 LKCC-060805-016F 10.0 0.077 81.2 LKCC-060805-016W 68.7 0.055 76.4

LKCC LMBA 335 LKCC-060905-005F 53.9 0.186 81.4 LKCC-060805-005W 500.6 0.108 76.3

LKCC LMBA 283 LKCC-060905-008F 22.6 0.129 81.7 LKCC-060805-008W 273.5 0.106 77.1

LKCC LMBA 350 LKCC-060905-021F 48.5 0.149 81.4 LKCC-060905-021W 521.6 0.088 76.1

LKCC LMBA 300 LKCC-060905-022F 40.4 0.094 81.9 LKCC-060905-022W 329.5 0.074 77.6

LKCC LMBA 275 LKCC-060905-023F 31.9 0.115 80.2 LKCC-060905-023W 292.7 0.071 74.5

LKCC LMBA 202 LKCC-060905-025F 14.3 0.066 80.5 LKCC-060905-025W 84.3 0.049 74.3

LKCC SPBA 174 LKCC-060805-017F 6.8 0.089 81.6 LKCC-060805-017W 41.9 0.074 76.8

LKCC SPBA 288 LKCC-060905-010F 14.1 0.117 79.4 LKCC-060805-010W 247.3 0.076 76.5

LKCC SPBA 275 LKCC-060905-026F 29.6 0.11 79.0 LKCC-060905-026W 230.3 0.078 72.7

LKCC SPBA 290 LKCC-060905-027F 30.6 0.106 80.2 LKCC-060905-027W 250.8 0.082 73.9

LKWC LMBA 450 LKWC-060905-001F 93.6 0.39 81.7 LKWC-060905-001W 1,269.7 0.224 75.2

LKWC LMBA 415 LKWC-060905-002F 79.1 0.33 80.9 LKWC-060905-002W 861.3 0.182 75.2

LKWC LMBA 342 LKWC-060905-003F 36.2 0.166 81.8 LKWC-060905-003W 511.5 0.107 77.8

LKWC LMBA 330 LKWC-060905-004F 31.7 0.241 80.7 LKWC-060905-004W 445.2 0.155 75.9

LKWC LMBA 286 LKWC-060905-005F 37.0 0.218 80.5 LKWC-060905-005W 289.9 0.125 79.5

LKWC LMBA 304 LKWC-060905-006F 41.0 0.178 81.4 LKWC-060905-006W 322.4 0.121 78.8

LKWC LMBA 195 LKWC-060905-007F 10.2 0.197 80.5 LKWC-060905-007W 73.4 0.123 75.3

LKWC LMBA 165 LKWC-060905-008F 6.2 0.154 80.5 LKWC-060905-008W 45.8 0.106 75.7

LKWC LMBA 470 LKWC-060905-012F 64.9 0.518 82.8 LKWC-060905-012W 1,369.30 0.371 74.6

LKWC LMBA 358 LKWC-060905-013F 59.8 0.139 80.7 LKWC-060905-013W 634.5 0.09 74.5

LKWC LMBA 320 LKWC-060905-014F 26.2 0.193 81.6 LKWC-060905-014W 439.4 0.152 75.2

LKWC LMBA 337 LKWC-060905-015F 27.5 0.127 82.4 LKWC-060905-015W 483.8 0.103 79.3

LKWC LMBA 336 LKWC-060905-017F 30.0 0.2 80.8 LKWC-060905-017W 490.2 0.128 74.8

LKWC LMBA 306 LKWC-060905-019F 19.6 0.115 81.3 LKWC-060905-019W 346.2 0.086 77.8

LKWC LMBA 282 LKWC-060905-020F 14.3 0.175 83.2 LKWC-060905-020W 254.6 0.129 79.3

LKWC LMBA 188 LKWC-060905-021F 4.0 0.124 80.7 LKWC-060905-021W 67.2 0.077 75.6

LKWC SPBA 363 LKWC-060905-009F 30.9 0.329 77.9 LKWC-060905-009W 609 0.187 70.6

LKWC SPBA 214 LKWC-060905-010F 11.1 0.171 79.8 LKWC-060905-010W 90.4 0.134 73.6

LKWC SPBA 388 LKWC-060905-022F 34.8 0.228 80.0 LKWC-060905-022W 627.9 0.144 72.6

LKWC SPBA 275 LKWC-060905-023F 13.8 0.094 79.5 LKWC-060905-023W 210.9 0.07 74.7

LKWC SPBA 243 LKWC-060905-024F 12.2 0.11 79.9 LKWC-060905-024W 138.1 0.075 74.5
Laboratory Methods of Chemical Analysis 5

Purpose and Scope

The purpose of this report is to present information 

regarding the concentration of metals in sport fish from the 

Whiskeytown Lake. Data were collected by USGS personnel. In addition, this data report adds to the limited number of 

studies for metal concentration in sport fish for this lake. The 

data from this report will be of use to scientists, managers, 

and other persons concerned with the metals concentrations in 

sport fish from Whiskeytown Lake and regional sport fisheries.

Field Methods and Sample 

Preservation Techniques

Field and laboratory preparatory methods were similar 

to those used by May and others (2000, 2005). All fish were 

collected by using electrofishing equipment and dip nets. Fish 

were held in clean containers with ambient water until they 

were weighed, to the nearest gram, and measured for standard 

and total length, in millimeters. After recording the length 

and mass, spines or scales were removed from each fish for 

future age determination. Each fish was then wrapped in clean, 

heavy-duty aluminum foil, labeled, placed in a plastic bag on 

wet ice and held for less than 8 hours. The fish were then taken 

to the USGS Dixon Field Station laboratory, where they were 

stored frozen until they were processed and sent to the contract 

laboratory for chemical analyses.

The processing of fish followed standard procedures 

(U.S. Environmental Protection Agency, 1995). Fish were 

handled with powder-free latex gloves, and dissections were 

performed on a new sheet of heavy-duty aluminum foil for 

each fish. High-quality stainless steel instruments and disposable scalpel blades were used in the processing of the fish 

samples. Scalpel blades were changed and instruments were 

cleaned thoroughly between samples. Cleaning the instruments involved washing with deionized water and laboratory 

detergent, acid washing, and finally rinsing with deionized 

water before and after dissection of each fish specimen.

Larger fish were thawed and scaled before dissection. 

Boneless and skinless fillet portions were taken from the left 

upper medial-axial region of the fish in an approximately 

rectangular shape. Excised tissues were placed directly into 

labeled, chemically cleaned borosilicate-glass jars on a pretared balance. The sample mass was recorded, and a Teflonlined lid was screwed atop each jar and sealed with Parafilm. 

Fish tissue samples were stored frozen in sealed sample jars 

until they were packed in coolers with dry ice and shipped to 

the contract analytical laboratory at Texas A&M University 

in College Station, Texas. The remaining whole-body of each 

fish was packaged into jars with Teflon-lined lids and analyzed 

for total metals.

Laboratory Methods of Chemical 

Analysis

Analysis of mercury (Hg) in fish samples was done at 

the Trace Element Research Laboratory (TERL) at Texas 

A&M University in College Station, Texas, under the direction of Dr. Robert Taylor. Samples were received frozen and 

were assigned unique identification numbers upon arrival at 

the laboratory. Tissue samples were transferred to labeled, 

tared polyethylene zip-lock bags, weighed, and lyophilized in 

a Labconco Freezone 12L freeze dryer. Moisture content was 

determined by weight loss following freeze drying for both 

fillet and whole-body samples. 

Procedures that require tissue samples to be freeze-dried 

to determine mercury concentrations result in removal of the 

original moisture in the sample. Additionally, tissue moisture is a relative measure of the quality of the tissue sample. 

Moisture content was determined by weight loss upon freeze 

drying and is expressed as weight percentage of the original wet sample. Depending on sample size, either the whole 

sample or a representative aliquot was frozen and then dried 

under vacuum until a constant weight was attained. Samples 

were prepared and dried using plastic materials to minimize 

potential contamination artifacts.

Both fillet and whole-body tissue samples were prepared 

for analysis by powdering freeze dried tissue in a Spex 6800 

cryomill. Samples were transferred to polycarbonate containers, chilled to liquid nitrogen temperatures, and ground to a 

fine powder with a stainless steel impacter in the cryomill. 

Homogenized samples were stored in zip-lock bags until analyzed. Aliquots of dry, powdered tissue samples were weighed 

to the nearest 0.0001 g and transferred to polypropylene digestion vessels. Samples were digested at a temperature of 95°C 

with nitric and hydrochloric acids and hydrogen peroxide (3, 

1, and 2 mL milliliters, respectively) in a CPI graphite block 

digester. Digest solutions were made to volume with Milli-Q 

18 MOhm (megaohm) deionized water and were stored in 

polyethylene bottles until analyzed.
6 Concentrations of mercury and other metals in black bass, Whiskeytown Lake, Shasta County, California, 2005

Three methods were used to determine metal concentrations in fish tissue: cold-vapor atomic absorption spectroscopy (CVAAS) for HgT in filets and whole body; inductively 

coupled plasma–mass spectroscopy (ICPMS); and, inductively 

coupled plasma–optical emission spectroscopy (ICP-OES) for 

other trace metals in the whole body.

Before samples were analyzed for Hg by CVAAS, the Hg 

was converted to the divalent mercury (Hg2+) form. Mercury 

was digested using a modified version of U.S. Environmental 

Protection Agency (USEPA) methods 245.5 and 245.6 (U.S. 

Environmental Protection Agency, 1991, 1995, 2001, 2003). 

Tissue samples were homogenized in the original sample containers by using a Tekmar Tissumizer, and then subsampled. 

Tissue subsamples were digested with nitric acid, sulfuric 

acid, potassium permanganate, and potassium persulfate in 

polypropylene tubes in a water bath at 90 to 95 degrees Celsius (°C). Before analysis, hydroxylamine hydrochloride was 

added to reduce excess permanganate, and the samples were 

brought to volume using distilled-deionized water.

In the CVAAS procedure for determination of Hg, 

divalent mercury (Hg2+) in aqueous samples (digests of tissue 

samples) is reduced to the elemental state (Hg0) by a strong 

reducing agent (stannous chloride). Gaseous Hg0 enters the 

sweep gas and is introduced into an atomic absorption cell, 

where light produced by a mercury-vapor lamp is absorbed 

by the free Hg0 atoms. Mercury concentration in the sample 

is determined by comparing light absorption of the sample 

with that of external calibration standards. The range limit of 

detection (LOD) for these analyses was 0.01 to 0.06 μg/g, dry 

weight (dw).

Inductively coupled plasma–mass spectroscopy was used 

during the metals scan to determine arsenic (As), cadmium 

(Cd), lead (Pb), and selenium (Se). Tissue digests were diluted 

with Milli-Q 18 MOhm deionized water as necessary to 

reduce their nitric acid concentrations to no greater than 2 percent v/v (volume by volume )and were then analyzed in pulse 

mode on a Perkin Elmer/Sciex DRC 2 ICP-MS instrument 

equipped with a dynamic reaction cell to eliminate molecular 

ion interferences on several elements (For example: As, Se, 

Cr, and V). Elemental concentrations were determined using 

internal standards to compensate for slight matrix effects and 

instrumental performance changes.

Inductively coupled plasma–optical emission spectroscopy was used to determine aluminum (Al), barium (Ba), calcium (Ca), chromium (Cr), copper (Cu), iron (Fe), potassium 

(K), magnesium (Mg), manganese (Mn), sodium (Na), nickel 

(Ni), phosphorus (P), sulfur (S), strontium (Sr), titanium (Ti), 

and zinc (Zn) in fish samples. Digest solutions were analyzed 

undiluted on an axial Spectro CirOs instrument, using internal 

standards to compensate for matrix effects and instrument 

drift. Final calculations utilized off-peak background correction and inter-element correction equations.

Quality Assurance and Quality Control

As part of normal quality-assurance (QA) and qualitycontrol (QC) procedures, a standard number of procedural 

blanks, laboratory duplicate samples, spiked samples, and 

standard reference materials were analyzed at the TERL during 2005–2006 for each set of fish samples from Whiskeytown 

Lake.

Procedural blanks were analyzed to quantify the amount 

of total mercury and other metals that may have been added 

inadvertently during sample processing. A total of 4 procedural blanks were analyzed. All QA/QC results were within 

acceptable limits for TERL standards for all the samples.

Laboratory replicate samples were analyzed to provide 

a measure of the precision of the methods used for analysis. 

Fifteen of the 63 samples were used as laboratory replicates. 

After the sample was homogenized, two separate subsamples 

were taken and analyzed. Replicates had to meet certain 

criteria to fall within the 95 percent confidence interval. If 

the sample concentration was within 2 to 10 times the limit 

of detection (LOD), the replicate had to be within 20 percent 

of the original value. If the sample concentration was greater 

than 10 times the LOD, the replicate sample had to be within 

10 percent of the original value.
Results and Discussion 7

Relative percentage difference (RPD) is another measure 

of precision for replicate samples. It is computed as 100 times 

the absolute value of the difference between two replicate 

analyses divided by their mean. Values of RPD ranged from 

0.24 to 9.17 percent, well within acceptable limits are set by 

TERL.

Spiked samples were analyzed to provide a measure of 

the accuracy of the methods used for analysis. Subsamples 

from 18 of the 63 fish were used as spiked samples and were 

evaluated for spike recovery. After the sample was homogenized, two separate subsamples were taken, one was processed 

as a sample, and the other spiked with a known quantity of 

analyte. Spike recovery was calculated as the measured concentration from the spiked sample minus the measured concentration from the unspiked sample, divided by the expected 

concentration in the spiked sample, and multiplied by 100 percent. Spike recoveries were determined to be between 93.5 to 

107 percent. Spike recoveries were considered acceptable if 

the average recovery was 85 to 115 percent (Robert Taylor, 

Trace Element Researach Laboratory, College Station, Texas, 

written commun., 2011).

Standard reference material (SRM) was analyzed to 

provide an estimate of range in accuracy of the laboratory 

instrument used for the determination of total mercury concentration and to ensure that this method produced results that 

were comparable to those obtained by an independent organization. The SRM used by the TERL was dogfish (Squalus sp.) 

muscle (DORM-2), certified by the National Research Council 

Canada (NRCC) as having a certified reference value (CRV) 

of 4.64 μg/g mercury (dry). The percentage recovery for the 

18 analyses of DORM-2 in the three sample sets ranged from 

82.7 to 107 percent, which is within acceptable limits (Robert 

Taylor, Trace Element Research Laboratory, College Station, 

Texas, written commun., 2011).

Results and Discussion

A total of 63 black bass (largemouth and spotted bass) 

were collected and processed for total mercury in fillet and 

whole-body samples (table 2). Whole-body samples were 

also analyzed for total metals (table 3). Total mercury in fillet samples ranged from 0.06 to 0.52 μg/g ww (wet weight) 

and 0.04 to 0.37 μg/g ww in whole-body samples. Mercury 

concentrations in 5 of the 30 black bass fillet samples that 

were of legal catch size (≥305 millimeters in length) exceeded 

the USEPA water-quality criterion for the protection of 

human health (0.3 μg/g ww), (U.S. Environmental Protection 

Agency, 2001). Black bass collected from Whiskeytown Lake 

show a general trend of increasing mercury concentration 

with increasing size (figure 2) and similar concentrations of 

total mercury in fillet and whole-body samples (r2 = 0.937) 

(figure 3). 

Each whole-body sample was processed for total metals 

scan. The following metals of ecological importance 

are reported alphabetically in μg/g dry weight with mean 

μg/g, range μg/g, and percent of non-detects (percent nd) in 

parentheses: arsenic (1.1μg/g , 1.82–0.746 μg/g), cadmium 

(1.11 μg/g , 1.35–0.024 μg/g, 2 percent nd), copper (2.18 μg/g 

, 9.54–0.89 μg/g), mercury (0.466 μg/g, 1.46–0.18 μg/g), 

nickel (5.83 μg/g, 172.0–0.46 μg/g, 24 percent nd), lead 

(0.088 μg/g, 0.205–0.047 μg/g, 90 percent nd), selenium 

(2.4 μg/g, 3.83–1.8 μg/g), and zinc (75.39 μg/g, 121.0–

48.4 μg/g). Visual comparisons of the ranges of data from 

metal scans indicated that there is no substantial difference 

between collection area or species for any metal.
8 Concentrations of mercury and other metals in black bass, Whiskeytown Lake, Shasta County, California, 2005 Table 3. Concentrations of selected metals and sulfur in whole-body samples of largemouth bass (Micropterus salmoides) and spotted bass (Micropterus punctulatus) collected from Whiskeytown Lake, California, June 2005.—Continued [Concentrations are in micrograms per gram (μg/g), dry weight except where otherwise noted. Geometric means are reported for element concentrations; arithmetic means are reported for length, moisture, and mass. Abbreviations: g, gram; LKBB, Brandy/Boulder Creek area; LKCC, Clear Creek area; LKWC, Whiskey Creek area; mm, millimeter; NC, mean was not calculated if the element was detected in fewer than <50 percent of the samples; –, not applicable; ^, differences in laboratory dectection limit are established by laboratory calibration curves for each batch of chemical analyses, therefore, they are not the same for every run; <, below the limit of detection; %, percent] Species Whole body code (site-date-sample) Total length (mm) Moisture (%) Sample mass (g) Aluminum^ Arsenic Barium Cadmium Calcium Chromium Copper Iron Mercury Magnesium 

Largemouth Bass (LMBA)

LKBB-060705-001W 360 76.7 644.1 140 0.93 10.9 1.35 60,700 11.3 2.9 280 0.377 1,650

LKBB-060705-002W 382 77.6 684 66.6 1.16 9.25 0.07 75,900 21.9 2.41 254 0.481 1,950

LKBB-060705-003W 403 73.3 878.6 <4.64 1.27 5.09 0.11 63,000 365 4.74 1,900 0.821 1,650

LKBB-060705-006W 345 76.8 474.3 9.94 1.01 10.9 0.05 68,300 35 2.52 288 0.359 1,700

LKBB-060705-007W 325 76.6 405.4 9.66 1.04 5.53 0.05 58,500 8.92 1.32 146 0.626 1,650

LKBB-060705-008W 330 75.4 432.1 8.61 0.99 5.64 0.05 55,400 5.62 3.51 111 0.5 1,590

LKBB-060705-009W 315 77.1 279.6 <4.66 0.89 4.27 0.05 46,800 4.36 1.6 108 0.578 1,560

LKBB-060705-011W 318 77.4 390.2 5.46 0.9 7.07 0.02 46,600 3.55 1.45 98.9 0.232 1,530

LKBB-060705-022W 210 76.4 109.8 6.7 1.2 7.52 0.06 69,700 <0.47 1.41 52.7 0.311 1,860

LKBB-060705-023W 180 76.8 62 6.6 1.29 7.86 0.05 62,100 3.14 2.52 71.7 0.232 1,840

LKBB-060705-025W 176 76.6 48.2 12.7 1.82 6.13 0.06 92,700 2.88 1.87 89.6 0.38 2,010

Mean for all LMBA collected 304 76.4 400 10.2 1.11 6.9 0.07 62,440 7.645 2.204 163.8 0.4142 1,720

Spotted bass (SPBA)

LKBB-060705-005W 385 73.1 708.6 6.4 0.85 4.93 0.05 58,800 79.6 1.97 710 0.619 1,570

LKBB-060705-012W 327 76.3 334.1 11.3 1.07 4.46 <0.02 56,800 2.77 1.22 72.3 0.729 1,630

LKBB-060705-013W 293 75.5 261.2 15.1 0.98 6.04 0.04 55,700 2.72 0.89 81.4 0.283 1,750

LKBB-060705-014W 311 76.5 337.7 8.08 0.9 4.91 0.03 48,000 0.55 1.29 66.3 0.819 1,570

LKBB-060705-017W 249 75.6 152.2 14.2 0.75 3.23 0.06 40,000 2.5 1.49 96.5 0.301 1,410

LKBB-060705-018W 238 74.3 148.4 6.01 1.27 6.06 0.05 54,800 1.06 1.4 49 0.331 1,660

LKBB-060705-019W 235 75.9 98.3 13.9 1.13 6.64 0.06 66,700 1.04 1.34 61.1 0.457 1,850

LKBB-060705-020W 212 73.8 82.6 <4.74 1.44 5.87 0.02 58,000 1.68 1.01 40.7 0.235 1,650

LKBB-060705-026W 173 77.1 44.8 <6.82 1.37 5.2 0.05 67,500 2.05 1.83 65.4 0.278 1,750

LKBB-060705-027W 145 77 26.9 13.6 1.17 7.02 0.09 68,700 1.71 1.97 79.3 0.208 1,820

Mean for all SPBA collected 257 75.5 219 8 1.07 5.32 0.04 56,800 2.358 1.396 83.71 0.3812 1,661

Mean for all fish (both species) 

from LKBB

–

–

– 9.127 1.092 6.132 0.05 59,700 4.367 1.773 119 0.3981 1,692

Percentage of fish from LKBB 

with concentrations above detection limits 

–

–

– 85.7 100 100 95.2 100 95.2 100 100 100 100

Table 3. Concentrations of selected metals and sulfur in whole-body samples of largemouth bass (Micropterus salmoides) and spotted bass (Micropterus punctulatus) collected from Whiskeytown Lake, California, June 2005.[Concentrations are in micrograms per gram (μg/g), dry weight except where otherwise noted. Geometric means are reported for element concentrations; arithmetic means are reported for length, moisture, and mass. Abbreviations: g, gram; LKBB, Brandy/Boulder Creek area; LKCC, Clear Creek area; LKWC, Whiskey Creek area; mm, millimeter; NC, mean was not calculated if the element was detected in fewer than <50 percent of the samples; –, not applicable; ^, differences in laboratory dectection limit are established by laboratory calibration curves for each batch of chemical analyses, therefore, they are not the same for every run; <, below the limit of detection; %, percent]
Results and Discussion 

9

Table 3. Concentrations of selected metals and sulfur in whole-body samples of largemouth bass (Micropterus salmoides) and spotted bass (Micropterus punctulatus) collected from Whiskeytown Lake, California, June 2005.—Continued[Concentrations are in micrograms per gram (μg/g), dry weight except where otherwise noted. Geometric means are reported for element concentrations; arithmetic means are reported for length, moisture, and mass. Abbreviations: g, gram; LKBB, Brandy/Boulder Creek area; LKCC, Clear Creek area; LKWC, Whiskey Creek area; mm, millimeter; NC, mean was not calculated if the element was detected in fewer than <50 percent of the samples; –, not applicable; ^, differences in laboratory dectection limit are established by laboratory calibration curves for each batch of chemical analyses, therefore, they are not the same for every run; <, below the limit of detection; %, percent] 

Species Whole body code (site-date-sample) Total length (mm) Moisture (%) Sample mass (g) Aluminum^ Arsenic Barium Cadmium Calcium Chromium Copper Iron Mercury Magnesium 

Largemouth Bass (LMBA)

LKCC-060805-001W 443 74.7 1,056.10 <4.88 1 3.6 0.12 57,400 4.11 1.78 90.7 1.02 1,550

LKCC-060805-002W 385 74.9 660.1 8.45 1.13 8.39 0.11 71,200 1.91 5.34 86.4 0.548 1,700

LKCC-060805-003W 370 75.7 699.5 78.2 1.12 7.32 0.12 60,500 1.65 2.2 173 0.551 1,630

LKCC-060805-004W 370 75.5 653.2 55.5 1.07 6.02 0.05 61,900 3.02 2.15 136 0.517 1,700

LKCC-060805-005W 335 76.3 500.6 14.1 0.94 8.24 0.14 53,300 4.01 9.54 91.5 0.456 1,450

LKCC-060805-006W 345 76 487.8 21.3 1.18 10.3 0.08 60,000 3.32 4.34 162 0.626 1,800

LKCC-060805-008W 283 77.1 273.5 11.9 0.98 7.25 0.09 57,900 1.91 1.36 102 0.465 1,670

LKCC-060805-011W 273 78.3 267.1 322 1.51 6.55 0.1 39,100 2.67 2.86 641 0.405 1,550

LKCC-060805-012W 223 75.2 125.8 15.3 1.18 3.59 0.03 59,000 0.91 1.3 57.4 0.18 1,570

LKCC-060805-013W 248 75.9 174.9 11.5 0.94 2.55 0.04 51,000 0.86 0.99 51.8 0.333 1,560

LKCC-060805-014W 260 79.1 213.3 14.7 0.78 3.4 0.04 28,400 2.22 1.23 97.2 0.343 1,390

LKCC-060805-015W 200 76.9 96.1 13 1.29 4.24 0.06 58,800 0.87 1.88 59 0.232 1,620

LKCC-060805-016W 195 76.4 68.7 5.25 1.11 3.34 0.03 57,900 0.61 1.12 43 0.235 1,660

LKCC-060905-021W 350 76.1 521.6 <4.68 1.13 7.64 0.05 65,400 1.76 1.13 84.6 0.368 1,730

LKCC-060905-022W 300 77.6 329.5 16.9 0.97 6.09 0.05 39,500 1.05 4.45 90 0.331 1,440

LKCC-060905-023W 275 74.5 292.7 8.17 1.08 6.4 0.05 48,100 1.69 4.15 86.3 0.278 1,410

LKCC-060905-025W 202 74.3 84.3 22.8 1.19 5.6 0.07 58,600 0.96 2.59 76.3 0.189 1,610

Mean for all LMBA collected 297.5 76.15 382.64 15.27 1.083 5.507 0.064 53,420 1.687 2.289 97.56 0.3765 1,586

Spotted 

bass (SPBA)LKCC-060805-010W 288 76.5 247.3 11 0.98 4.75 0.04 46,900 1.01 0.98 68.2 0.325 1,560 LKCC-060805-017W 174 76.8 41.9 7.24 1.18 3.07 0.07 51,900 0.81 1.03 50.5 0.317 1,700 LKCC-060905-026W 275 72.7 230.3 <4.66 0.99 5.47 0.1 49,800 4.36 1 146 0.284 1,380 LKCC-060905-027W 290 73.9 250.8 10.3 0.91 5.13 0.08 46,700 3.49 1.44 117 0.313 1,450

Mean for all SPBA collected 256.8 74.98 192.57 6.612 1.011 4.498 0.067 48,780 1.875 1.098 87.58 0.3094 1,518

Mean for all fish (both species) 

collected from LKCC

– – – 13.02 1.06 5.29 0.064 52,500 1.721 1.99 95.57 0.3627 1,573

Percentage of fish from LKCC 

with concentrations above detection limits

– – – 85.7 100 100 100 100 100 100 100 100 100
10 Concentrations of mercury and other metals in black bass, Whiskeytown Lake, Shasta County, California, 2005 Table 3. Concentrations of selected metals and sulfur in whole-body samples of largemouth bass (Micropterus salmoides) and spotted bass (Micropterus punctulatus) collected from Whiskeytown Lake, California, June 2005.—Continued [Concentrations are in micrograms per gram (μg/g), dry weight except where otherwise noted. Geometric means are reported for element concentrations; arithmetic means are reported for length, moisture, and mass. Abbreviations: g, gram; LKBB, Brandy/Boulder Creek area; LKCC, Clear Creek area; LKWC, Whiskey Creek area; mm, millimeter; NC, mean was not calculated if the element was detected in fewer than <50 percent of the samples; –, not applicable; ^, differences in laboratory dectection limit are established by laboratory calibration curves for each batch of chemical analyses, therefore, they are not the same for every run; <, below the limit of detection; %, percent] Species Whole body code (site-date-sample) Total length (mm) Moisture (%) Sample mass (g) Aluminum^ Arsenic Barium Cadmium Calcium Chromium Copper Iron Mercury Magnesium 

Largemouth Bass (LMBA)

LKWC-060905-001W 450 75.2 1,269.7 <4.38 0.94 7.06 0.17 58,000 1.07 2.77 78.1 0.902 1,500

LKWC-060905-002W 415 75.2 861.3 4.75 1.12 9.84 0.12 59,400 1.64 2.25 101 0.735 1,570

LKWC-060905-003W 342 77.8 511.5 106 1.27 9.53 0.11 67,400 2.96 1.86 195 0.484 1,840

LKWC-060905-004W 330 75.9 445.2 11.4 0.95 7.59 0.12 41,100 3.72 2.67 177 0.643 1,380

LKWC-060905-005W 286 79.5 289.9 14 1.25 15.3 1.04 57,000 0.806 4.46 123 0.61 1,700

LKWC-060905-006W 304 78.8 322.4 13.5 0.93 7.33 0.28 45,500 2.82 4.97 135 0.573 1,600

LKWC-060905-007W 195 75.3 73.4 10.2 1.39 4.35 0.062 58,100 1.25 2.01 69.4 0.497 1,790

LKWC-060905-008W 165 75.7 45.8 17.7 1.52 4.93 0.112 59,200 2.11 2.21 80.7 0.438 1,730

LKWC-060905-012W 470 74.6 1,369.3 <4.54 1.08 4.32 0.17 52,200 3.82 1.02 83.7 1.46 1,490

LKWC-060905-013W 358 74.5 634.5 4.55 0.99 6.86 0.07 45,600 1.84 1.33 92 0.354 1,420

LKWC-060905-014W 320 75.2 439.4 <4.38 0.96 2.31 0.08 34,400 2.51 1.31 64.8 0.611 1,280

LKWC-060905-015W 337 79.3 483.8 26.8 0.92 7.62 0.05 39,800 1.47 1.63 84.1 0.499 1,430

LKWC-060905-017W 336 74.8 490.2 <4.38 1.24 4.95 0.05 50,900 4.36 1.59 81.6 0.509 1,450

LKWC-060905-019W 306 77.8 346.2 8.57 1.04 7.01 0.07 46,100 1.47 2.56 90.9 0.386 1,600

LKWC-060905-020W 282 79.3 254.6 <4.74 0.89 5.26 0.09 45,700 1.52 1.57 79.5 0.625 1,500

LKWC-060905-021W 188 75.6 67.2 9.33 1.1 4.64 0.14 59,100 1.31 2.87 51.1 0.314 1,650

Mean for all LMBA collected 317.8 76.53 494.03 7.533 1.085 6.244 0.115 50,450 1.934 2.116 93.13 0.5607 1,551

Spotted bass 

(SPBA)

LKWC-060905-009W 363 70.6 609 <4.70 0.86 1.94 0.07 30,400 1.97 1.27 67.5 0.636 1,150

LKWC-060905-010W 214 73.6 90.4 <4.72 1.07 6.54 0.64 50,300 1.01 1.25 40.6 0.508 1,690

LKWC-060905-022W 388 72.6 627.9 <4.66 1.1 5.99 0.03 54,800 1.84 1.02 59.1 0.524 1,590

LKWC-060905-023W 275 74.7 210.9 7.79 1.68 4.71 0.06 54,200 0.602 1.84 43.5 0.277 1,700

LKWC-060905-024W 243 74.5 138.1 4.54 1.51 3.83 0.06 50,200 0.648 1.51 45.7 0.295 1,640

Mean for all SPBA collected 296.6 73.2 335.27 NC 1.207 4.24 46,950 1.074 1.351 50.3 0.4248 1,538

Mean for all fish (both species) 

collected for LKWC

–

–

– 6.235 1.113 5.69 0.11 49,590 1.681 1.902 80.42 0.5248 1,548

Percentage of fish from LKWC 

with concentrations above detection limits

–

–

– 61.9 100 100 100 100 100 100 100 100 100

Mean for all fish (both species) 

collected from sites

–

–

– 9.05 1.09 5.69 0.07 53,770 2.329 1.886 97.07 0.4232 1,603
Results and Discussion 11

Table 3. Concentrations of selected metals and sulfur in whole-body samples of largemouth bass (Micropterus salmoides) and spotted bass (Micropterus punctulatus) collected from Whiskeytown Lake, California, June 2005.—Continued[Concentrations are in micrograms per gram (μg/g), dry weight except where otherwise noted. Geometric means are reported for element concentrations; arithmetic means are reported for length, moisture, and mass. Abbreviations: g, gram; LKBB, Brandy/Boulder Creek area; LKCC, Clear Creek area; LKWC, Whiskey Creek area; mm, millimeter; NC, mean was not calculated if the element was detected in fewer than <50 percent of the samples; –, not applicable; ^, differences in laboratory dectection limit are established by laboratory calibration curves for each batch of chemical analyses, therefore, they are not the same for every run; <, below the limit of detection; %, percent]

Species Whole body code (site-date-sample) Total length (mm) Moisture (%) Sample mass (g) Manganese Nickel^ Phosphorus Potassium Sodium Sulfur Selenium Strontium Titanium Zinc

Largemouth Bass (LMBA)

LKBB-060705-001W 360 76.7 644.1 35.3 4.91 32,700 11,900 4,770 8,360 2.42 125 5.43 81.7

LKBB-060705-002W 382 77.6 684 19.6 10.5 38,500 11,700 5,140 7,850 2.11 130 3.91 61.7

LKBB-060705-003W 403 73.3 878.6 33.8 172 32,900 10,500 4,140 8,120 1.96 98.1 1.26 60.8

LKBB-060705-006W 345 76.8 474.3 15.5 14.3 35,400 11,700 5,120 8,400 2.35 133 1.14 64.2

LKBB-060705-007W 325 76.6 405.4 5.46 2.71 32,200 11,900 4,350 9,050 2.31 116 1.34 66.1

LKBB-060705-008W 330 75.4 432.1 5.84 2.57 30,400 11,200 4,160 8,990 2.16 87 0.93 67.2

LKBB-060705-009W 315 77.1 279.6 6.55 2.18 27,900 12,600 4,020 9,820 2.59 75.9 0.78 70.1

LKBB-060705-011W 318 77.4 390.2 3.05 1.62 27,200 12,400 4,390 8,760 2.41 94.2 0.86 60.9

LKBB-060705-022W 210 76.4 109.8 10.3 <0.469 37,400 10,900 3,870 7,860 2.36 105 1.34 76.4

LKBB-060705-023W 180 76.8 62 15.7 1.34 34,600 11,100 4,000 8,420 2.58 105 1.06 92.8

LKBB-060705-025W 176 76.6 48.2 8.4 1.25 44,700 10,100 5,120 8,090 2.28 146 2.41 121

Mean for all LMBA collected 304 76.4 400 11.1 3.577 33,670 11,430 4,438 8,502 2.314 108.5 1.501 73.13

Spotted bass (SPBA)

LKBB-060705-005W 385 73.1 708.6 10.9 30.4 31,600 10,700 4,040 8,040 1.92 92.7 0.93 59.9

LKBB-060705-012W 327 76.3 334.1 2.03 0.89 31,900 12,300 4,240 8,760 2.44 98 1.15 82.4

LKBB-060705-013W 293 75.5 261.2 3.01 0.8 31,900 13,500 4,130 8,950 2.1 110 1.28 71

LKBB-060705-014W 311 76.5 337.7 2.08 <0.461 28,600 13,000 3,640 8,500 2.24 85.3 0.92 62.8

LKBB-060705-017W 249 75.6 152.2 8.09 0.96 25,400 12,100 3,200 7,730 1.95 72.6 3.62 56.5

LKBB-060705-018W 238 74.3 148.4 3.94 0.55 31,100 11,500 3,860 7,750 2.08 98.9 1.08 91.5

LKBB-060705-019W 235 75.9 98.3 2.69 <0.477 35,800 11,100 3,150 8,150 2.34 126 1.3 92.3

LKBB-060705-020W 212 73.8 82.6 3.68 0.69 32,600 10,500 3,670 7,330 1.85 108 0.94 97.1

LKBB-060705-026W 173 77.1 44.8 4.34 1.17 37,800 11,200 4,310 9,090 2.46 114 1.17 116

LKBB-060705-027W 145 77 26.9 13.3 0.74 37,300 11,900 4,110 9,110 2.74 111 1.67 113

Mean for all SPBA collected 257 75.5 219 4.367 0.9065 32,190 11,740 3,814 8,319 2.196 100.5 1.28 81.77

Mean for all fish (both species) 

from LKBB

–

–

– 7.117 1.86 32,960 11,580 4,129 8,414 2.257 104.6 1.391 77.13

Percentage of fish from LKBB 

with concentrations above detection limits 

–

–

– 100 85.7 100 100 100 100 100 100 100 100
12 Concentrations of mercury and other metals in black bass, Whiskeytown Lake, Shasta County, California, 2005 Table 3. Concentrations of selected metals and sulfur in whole-body samples of largemouth bass (Micropterus salmoides) and spotted bass (Micropterus punctulatus) collected from Whiskeytown Lake, California, June 2005.—Continued [Concentrations are in micrograms per gram (μg/g), dry weight except where otherwise noted. Geometric means are reported for element concentrations; arithmetic means are reported for length, moisture, and mass. Abbreviations: g, gram; LKBB, Brandy/Boulder Creek area; LKCC, Clear Creek area; LKWC, Whiskey Creek area; mm, millimeter; NC, mean was not calculated if the element was detected in fewer than <50 percent of the samples; –, not applicable; ^, differences in laboratory dectection limit are established by laboratory calibration curves for each batch of chemical analyses, therefore, they are not the same for every run; <, below the limit of detection; %, percent] Species Whole body code (site-date-sample) Total length (mm) Moisture (%) Sample mass (g) Manganese Nickel^ Phosphorus Potassium Sodium Sulfur Selenium Strontium Titanium Zinc

Largemouth Bass (LMBA)

LKCC-060805-001W 443 74.7 1,056.10 4.91 1.85 31,600 11,100 4,000 8,200 2.24 89.6 0.9 61.9

LKCC-060805-002W 385 74.9 660.1 7.34 0.9 36,400 10,300 4,340 7,880 1.8 136 1.21 65.3

LKCC-060805-003W 370 75.7 699.5 10.6 0.87 33,200 11,600 4,430 8,090 2.04 116 3.19 71.1

LKCC-060805-004W 370 75.5 653.2 7.53 1.56 33,600 11,500 4,400 7,990 2.06 96.4 3.14 58.7

LKCC-060805-005W 335 76.3 500.6 7.05 1.62 29,200 10,600 4,500 7,990 2.21 90.7 1.48 70.8

LKCC-060805-006W 345 76 487.8 7.87 1.42 32,500 12,600 4,410 8,670 2.04 123 1.52 73.2

LKCC-060805-008W 283 77.1 273.5 12.5 0.64 32,600 12,400 4,190 8,250 2.21 108 1.55 74.3

LKCC-060805-011W 273 78.3 267.1 25 1.66 25,200 12,700 3,490 8,440 2.31 61.1 10.6 66

LKCC-060805-012W 223 75.2 125.8 7.8 <0.465 32,700 10,300 3,500 8,440 2.05 87.7 1.45 72.9

LKCC-060805-013W 248 75.9 174.9 4.08 <0.483 29,900 11,400 3,520 9,090 2.02 66.4 1.3 67.9

LKCC-060805-014W 260 79.1 213.3 3.22 0.59 20,500 13,600 3,210 9,990 2.24 48.7 1.49 53.8

LKCC-060805-015W 200 76.9 96.1 14.6 <0.468 33,100 11,500 4,010 8,780 2.13 82.5 1.27 79.7

LKCC-060805-016W 195 76.4 68.7 5.04 <0.479 33,300 12,000 3,670 9,250 2.4 80.3 1.04 84.1

LKCC-060905-021W 350 76.1 521.6 13 0.78 34,600 11,600 4,530 8,150 2.26 117 0.97 72.1

LKCC-060905-022W 300 77.6 329.5 5.29 0.69 24,300 12,300 4,190 8,990 2.34 81.3 1.11 63.3

LKCC-060905-023W 275 74.5 292.7 9.48 0.88 27,600 10,600 3,760 8,270 2.11 86.7 0.96 66.5

LKCC-060905-025W 202 74.3 84.3 13.4 <0.488 33,000 11,000 3,850 8,540 2.09 89.7 1.66 84

Mean for all LMBA collected 297.5 76.15 382.64 8.18 0.672 30,480 11,560 3,979 8,514 2.145 89.06 1.587 69.28

- Spot

ted bass 

(SPBA)

LKCC-060805-010W 288 76.5 247.3 2.71 0.61 28,200 11,800 3,510 8,480 2.13 92.5 1.09 72.7

LKCC-060805-017W 174 76.8 41.9 3.09 <0.481 30,900 12,000 3,750 8,550 2.7 82.9 1.01 115

LKCC-060905-026W 275 72.7 230.3 4.13 0.52 28,500 10,000 3,340 7,490 2.03 82.4 6.29 56.4

LKCC-060905-027W 290 73.9 250.8 3.07 <0.467 27,200 10,800 3,320 7,520 1.89 92.2 16.2 71.5

Mean for all SPBA collected 256.8 74.98 192.57 3.21 0.3643 28,670 11,120 3,476 7,994 2.167 87.37 3.254 76.2

Mean for all fish (both species) 

collected from LKCC

–

–

– 6.845 0.5981 30,130 11,480 3,878 8,412 2.149 88.73 1.82 70.55

Percentage of fish from LKCC 

with concentrations above detection limits

–

–

– 100 66.7 100 100 100 100 100 100 100 100
Results and Discussion 13

Table 3. Concentrations of selected metals and sulfur in whole-body samples of largemouth bass (Micropterus salmoides) and spotted bass (Micropterus punctulatus) collected from Whiskeytown Lake, California, June 2005.—Continued[Concentrations are in micrograms per gram (μg/g), dry weight except where otherwise noted. Geometric means are reported for element concentrations; arithmetic means are reported for length, moisture, and mass. Abbreviations: g, gram; LKBB, Brandy/Boulder Creek area; LKCC, Clear Creek area; LKWC, Whiskey Creek area; mm, millimeter; NC, mean was not calculated if the element was detected in fewer than <50 percent of the samples; –, not applicable; ^, differences in laboratory dectection limit are established by laboratory calibration curves for each batch of chemical analyses, therefore, they are not the same for every run; <, below the limit of detection; %, percent]

Species Whole body code (site-date-sample) Total length (mm) Moisture (%) Sample mass (g) Manganese Nickel^ Phosphorus Potassium Sodium Sulfur Selenium Strontium Titanium Zinc

Largemouth Bass (LMBA)

LKWC-060905-001W 450 75.2 1,269.7 10.3 0.62 30,600 10,100 4,060 7,720 2.09 99.4 1.16 59.3

LKWC-060905-002W 415 75.2 861.3 8.99 1.01 30,500 10,500 4,240 7,310 2.46 101 1.64 70.6

LKWC-060905-003W 342 77.8 511.5 17.7 1.05 36,300 12,700 4,860 9,360 2.92 112 9.4 72.3

LKWC-060905-004W 330 75.9 445.2 5.95 1.65 24,600 10,700 3,710 7,710 2.92 60.4 3.33 70.2

LKWC-060905-005W 286 79.5 289.9 37.2 0.71 31,200 11,900 4,780 8,620 3.73 84.8 1.21 71.8

LKWC-060905-006W 304 78.8 322.4 11 0.59 27,800 13,800 5,090 9,770 2.99 66.8 7.81 74.5

LKWC-060905-007W 195 75.3 73.4 5.56 <0.470 32,800 11,400 4,050 8,940 2.58 81.6 1.28 94.1

LKWC-060905-008W 165 75.7 45.8 11.7 1.02 32,800 11,300 3,720 8,560 2.16 84.8 1.52 98.3

LKWC-060905-012W 470 74.6 1,369.3 4.56 1.47 28,900 10,900 4,080 6,960 2.65 73.6 0.84 55

LKWC-060905-013W 358 74.5 634.5 14.8 1.54 26,300 10,400 3,770 7,550 2.78 87.2 0.8 104

LKWC-060905-014W 320 75.2 439.4 4.07 0.68 22,300 11,600 3,310 9,280 2.78 46.5 3.37 62.1

LKWC-060905-015W 337 79.3 483.8 16.2 0.87 24,700 13,200 4,190 8,900 3.72 63.2 1.21 62.5

LKWC-060905-017W 336 74.8 490.2 4.32 1.68 28,500 10,300 4,120 8,480 2.49 84.8 0.78 64.2

LKWC-060905-019W 306 77.8 346.2 4.08 <0.450 27,600 12,900 4,170 9,310 2.8 89.9 0.98 67.8

LKWC-060905-020W 282 79.3 254.6 9.65 0.66 27,400 12,500 4,560 9,090 3.83 71.6 0.77 69

LKWC-060905-021W 188 75.6 67.2 6.24 0.46 32,600 11,100 4,060 9,150 2.24 89.6 1.05 94.7

Mean for all LMBA collected 317.8 76.53 494.03 8.771 0.7762 28,840 11,530 4,149 8,504 2.776 79.32 1.598 73.09

Spotted bass 

(SPBA)

LKWC-060905-009W 363 70.6 609 1.8 0.65 20,100 9,640 2,730 7,030 2.18 49.7 0.85 48.4

LKWC-060905-010W 214 73.6 90.4 5.9 <0.470 29,500 10,500 3,550 7,790 3.62 68.2 0.78 100

LKWC-060905-022W 388 72.6 627.9 2.42 1.01 29,700 10,300 3,740 7,810 1.98 108 0.81 71.2

LKWC-060905-023W 275 74.7 210.9 3.01 <0.440 30,800 11,500 3,350 7,930 2.31 103 0.9 80

LKWC-060905-024W 243 74.5 138.1 2.69 <0.450 29,600 11,700 3,390 7,740 2.72 91.4 0.9 93

Mean for all SPBA collected 296.6 73.2 335.27 2.908 NC 27,610 10,700 3,334 7,653 2.503 80.81 0.8475 76.17

Mean for all fish (both species) 

collected for LKWC

– – – 6.744 0.6537 28,540 11,330 3,939 8,293 2.708 79.67 1.374 73.81

Percentage of fish from LKWC 

with concentrations above detection limits

– – – 100 76.2 100 100 100 100 100 100 100 100

Mean for all fish (both species) 

collected for from sites

– – – 6.9 0.8993 30,490 11,460 3,980 8,373 2.36 90.44 1.515 73.78
14 Concentrations of mercury and other metals in black bass, Whiskeytown Lake, Shasta County, California, 2005

Whiskey Creek Arm

Brandy/Boulder Creek Area

TOTAL MERCURY IN FILLET, IN MICROGRAMS PER GRAM OF WET WEIGHT

100 200 300 400 500

TOTAL LENGTH, IN MILLIMETERS

EXPLANATION

0.0

0.1

0.2

0.3

0.4

0.5

0.6

Largemouth bass (LMBA) Spotted bass (SPBA)

Clear Creek Arm

Whiskey Creek Arm

Brandy/Boulder Creek Area

Clear Creek Arm

Figure 2. Mercury concentration for all bass (Micropterus spp.) samples collected from Whiskeytown Lake, California, 2005 in relation 

to total length.

from Whiskeytown Lake are not as elevated as values from 

fish in the adjacent Trinity Lake and watershed (May and 

others 2005), it is evident that more samples are needed to 

thoroughly evaluate the potential risk these fish may pose to 

human and wildlife consumers. 

The data presented in this report represent a baseline 

for future monitoring efforts. Black bass in Whiskeytown 

Lake have elevated concentrations of total mercury and 

show a bioaccumulation effect of increasing mercury with 

increasing size. While mercury values from fish collected 
References 15

y = 0.5894x + 0.0135

R2 = 0.937

0.1

0.0

0.2

0.3

0.4

0.5

0.6

TOTAL MERCURY IN WHOLE BODY, IN MICROGRAMS PER GRAM OF WET WEIGHT

TOTAL MERCURY IN FILLET, IN MICROGRAMS PER GRAM OF WET WEIGHT 

0.0 0.1 0.2 0.3 0.4 0.5 0.6

Figure 3. Correlation plot of mercury concentration in fillet samples in relation to whole-body samples for for all bass (Micropterus 

spp.) samples collected from Whiskeytown Lake, California, 2005. 

Acknowledgements

Funding for this study was provided by the USGS–NPS 

Water Quality Cooperative Program, and the U.S. Department 

of Interior Burned Area Rehabilitation Program. We thank 

Jennifer Gibson, Russ Weatherbee, and Brian Rasmussen of 

the Whiskeytown National Recreation Area, who helped with 

procuring funding for these analyses and assisted with logistics associated with the collection. Skylar Feltman of USGS 

Biological Resources Discipline helped with processing fish 

samples. 

References

Alpers, C.N., Hunerlach, M.P., May, J.T., and Hothem, R.L., 

2005, Mercury contamination from historic gold mining in 

California: U.S. Geological Survey Fact Sheet 2005–3014, 

2nd ed., 6 p. Available at http://pubs.usgs.gov/fs/2005/3014/

fs2005_3014_v1.1.pdf

California Department of Conservation, 2000, California’s 

Abandoned mine lands: Chapter 3.3 Clear Creek Watershed, 

p. 41–47,Volume II: A report on the magnitude and Scope of 

the issue in the State: California Department of Conservation, Abandoned Mines Unit, Sacramento, California, 137 p. 

May, J.T., Hothem, R.L., Alpers, C.N., and Law, M.A., 2000, 

Mercury bioaccumulation in fish in a region affected by historic gold mining: The South Yuba River, Deer Creek, and 

Bear River Watersheds, California, 1999: U.S. Geological 

Survey, Open-File Report 00-367, 35 p. Available at 

http://pubs.usgs.gov/of/2000/0367/report.pdf

May, J.T., Hothem, R.L, and Alpers, C.N., 2005, Mercury 

Concentrations in fishes from select water bodies in Trinity 

County, California, 2000–2002: U.S. Geological Survey 

Open-File Report 2005–1321, 14 p. Available at 

http://pubs.usgs.gov/of/2005/1321/USGS_2005-1321.pdf

Moore, J.N., and Hughes, D., 2003, Trace metals in sediments 

of a mine impacted river basin: Clear Creek, California 

Project, Final Report: Department of Geology, University 

of Montana, Missoula, masters thesis, December 30, 2003, 

136 p. 
16 Concentrations of mercury and other metals in black bass, Whiskeytown Lake, Shasta County, California, 2005

National Park Service, 1999, General Management Plan and 

Environmental Impact Statement Whiskeytown Unit Shasta 

County, California, 117 p., accessed June, 2008 at http://

www.nps.gov/whis/parkmgmt/upload/GMPfinal.pdf

U.S. Environmental Protection Agency, 1991, Methods for 

the determination of metals in environmental samples: U.S. 

Environmental Protection Agency, Office of Research and 

Development, Environmental Monitoring Systems Laboratory, EPA- PA/600 4-91-010, 293 p.

U.S. Environmental Protection Agency, 1995, Guidance for 

assessing chemical contaminant data for use in fish advisories, Volume 1, Fish sampling and analysis (2nd ed.): 

U.S. Environmental Protection Agency, Office of Water, 

EPA823-R-95-007, variously paged.

U.S. Environmental Protection Agency, 2001, Water quality 

criterion for protection of human health—Methylmercury: 

U.S. Environmental Protection Agency, Office of Water, 

EPA-823-R-01-001, 269 p.

U.S. Environmental Protection Agency, 2003, Draft update 

IVA of SW-846, 7000 series, Method 7473, Mercury in solids and solutions by thermal decomposition, amalgamation, 

and atomic absorption spectrophotometry: U.S. Environmental Protection Agency, Office of Water, accessed July, 

2005 at 

http://www.epa.gov/epaoswer/hazwaste/test/up4a.htm#7_

series
May and others—Concentrations of Mercury and other Metals in Black Bass (Micropterus spp.) from Whiskeytown Lake, Shasta County, California, 2005—

Open File Report 2011–1297

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