Biomonitoring of Environmental Status and Trends (BEST) 

Program: Environmental Contaminants and their Effects on 

Fish in the Columbia River Basin

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2004—5154

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Front cover. The U.S. map shows the Columbia River Basin (green) and stations sampled in this study (orange). Shown in gray are

major river basins and stations in the conterminous U.S. sampled during other Biomonitoring of Environmental Status and Trends Program (BEST) investigations.
Biomonitoring of Environmental Status and

Trends (BEST) Program: Environmental

Contaminants and their Effects on Fish in

the Columbia River Basin

By Jo Ellen Hinck, Christopher J. Schmitt, Timothy M. Bartish, Nancy D. Denslow,

Vicki S. Blazer, Patrick J. Anderson, James J. Coyle, Gail M. Dethloff, and Donald

E. Tillitt

Scientific Investigations Report 2004—5154

U.S. Department of the Interior

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

Gale A. Norton, Secretary

U.S. Geological Survey

Charles G. Groat, Director

U.S. Geological Survey, Reston, Virginia: 2004

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Hinck, J.E., Schmitt, C.J.; Bartish, T. M., Denslow, N.D.; Blazer, V.S., Anderson, P.J.; Coyle, J.J., Dethloff, G.M. and Tillitt, D.E., 2004, Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental Contaminants and 

their Effects on Fish in the Columbia River Basin: U.S. Geological Survey, Columbia Environmental Research Center, 

Columbia, Missouri, Scientific Investigations Report 2004—5154, 125 p.
In Memoriam 

This report is dedicated to Tim Bartish, our 

leader of the BEST Program. We were all saddened 

by the sudden loss of Tim when he passed away from 

pancreatic cancer on 13 February 2004. Tim provided the BEST Program with leadership since 1996; 

first as assistant coordinator, then as coordinator. 

Tim was a true leader and provided the program with 

a stable course of direction while he was at the helm. 

He was both a biologist concerned about the integrity of our nation’s aquatic resources and a friend 

concerned about the people that he interacted with 

each and every day. The BEST Program has moved 

from a conceptual model, through the demonstration 

stages, to a true national monitoring program under 

the direction, patience, and care of Tim. We feel that 

the program has made tremendous progress over the 

past few years, and that progress would have never 

been realized without the foresight, guidance, and 

strength of Tim Bartish. 
ii Environmental Contaminants and their Effects on Fish 
Preface iii 

Preface 

The study described in this report was conducted as part of the USGS Biomonitoring of Environmental Status and Trends (BEST) program. BEST evolved from previous federal monitoring programs including the National Pesticide Monitoring Program (NPMP) of the 1960s which 

was renamed the National Contaminant Biomonitoring Program (NCBP) in the early 1970s 

which also screened for elemental contaminants. The U.S. Fish and Wildlife Service (USFWS) 

participated in the NPMP and maintained the NCBP by monitoring concentrations of persistent contaminants in freshwater fish and avian wildlife through 1986. The BEST program was 

initiated in the 1990s to build on information produced by these earlier programs and to provide 

more biologically relevant information regarding potential contaminant effects on lands and 

species under USFWS management. The program was transferred to the National Biological Survey in 1993 and ultimately to USGS in 1996. The Large Rivers program of BEST has 

principal emphasis to identify, monitor, and assess the effects of chemical contaminants on 

the fish health in the nation’s large rivers. The 1997 Columbia River Basin (CRB) study was 

implemented with a companion investigation of the Rio Grande Basin. The 1997 investigations 

represented continuations of a pilot study conducted in the Mississippi River Basin in 1995. 

Acknowledgements 

This study was conducted jointly by the USGS, through its research centers in Columbia, Missouri (Columbia Environmental Research Center, CERC) and Kearneysville, West Virginia 

(Leetown Science Center, LSC); and the U.S. Fish and Wildlife Service (USFWS), through its 

Ecological Services (ES) Field Offices in Portland, Oregon, Spokane, Washington, and Boise, 

Idaho. The study was facilitated through a Research Work Order with the USGS-Florida Cooperative Fish and Wildlife Research Unit at the University of Florida (UF), Gainesville, Florida. 

Many individuals representing USGS, USFWS, UF, and other organizations contributed 

substantially during the conduct of the study. C. Bunck (USGS) managed the BEST program 

during most of the study, and S. Finger (USGS) coordinated much of the work. S. Zylstra and 

T. Buerger organized and J. Buck (all USFWS) supervised field portions of the study. Chemical analyses were conducted at laboratories operated by Mississippi State University and the 

Research Triangle Institute through contracts with the USFWS. These contracts are managed by the USFWS Patuxent Analytical Control Facility (PACF); J. Moore and P. McDonald 

(PACF) facilitated this part of the study. Laboratory analyses for biomarkers were performed 

by D. Nicks and S. Birke (CERC), D. Bowling (LSC), and M. Chow and K. Kroll (UF). D. 

Bowling and K. Spring (LSC) assisted in the histology slide preparation, and E. Frankenberry 

(LSC) for assisted with the macrophage aggregate evaluation. A. Donahue (CERC) aged 

the fish, produced report graphics, and edited draft versions of the report. B. Wright and M. 

Ellersieck assisted with statistical analyses. R. Lipkin (CERC) managed the bibliographic 

database and prepared the report for publication. J. Whyte (CERC), P. Cirone (USEPA, Seattle, 

Washington), and M. Munn (USGS Tacoma, Washington) reviewed all or portions of the report 

and provided additional information. 
iv Environmental Contaminants and their Effects on Fish 
Contents v 

Contents 

Preface .......................................................................................................................................................... iii


Acknowledgements..................................................................................................................................... iii


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


Introduction ................................................................................................................................................... 2


Columbia River Basin Overview ........................................................................................................ 2


Hydrology and Environmental Setting ..................................................................................... 2


Land Ownership .......................................................................................................................... 4


Urban and Metropolitan Areas................................................................................................. 4


Hydroelectric Power and Dams ............................................................................................... 5


Water Quality ............................................................................................................................... 5


Impairments ........................................................................................................................ 5


Fish Consumption Advisories........................................................................................... 6


U.S. Department of the Interior Resources at Risk from Contaminants in the CRB ........ 6


Extant Sources of Information on Contaminants in the CRB ........................................................ 6


National Contaminant Biomonitoring Program...................................................................... 6


National Estuary Program ....................................................................................................... 7


Columbia River Basin Fish Contaminant Survey.................................................................... 7


Contaminant Load Contributions to the Lower Columbia River (LCR) ................................ 7


Bi-State Water Quality Program ............................................................................................... 8


USGS National Water Quality Assessment (NAWQA) Program ......................................... 8


Major Sources of Contaminants to the Columbia River Basin ..................................................... 9


Air Pollution Patterns ................................................................................................................. 9


Agriculture ................................................................................................................................. 10


Mining and Extractive Industries ........................................................................................... 10


Industrial and Municipal Sources.......................................................................................... 10


Comprehensive Environmental Response, Compensation, and Liability Act ................. 11


Materials and Methods ............................................................................................................................. 13


Collection Sites .................................................................................................................................. 13


Target Species and Sampling Strategy .......................................................................................... 13


Monitoring Methods Overview........................................................................................................ 13


Field Procedures ................................................................................................................................ 17


Fish Collection .......................................................................................................................... 17


Sample Processing................................................................................................................... 17


Laboratory Analyses ......................................................................................................................... 18


Composite Sample Preparation.............................................................................................. 18


Elemental Analysis and Moisture Content ........................................................................... 18


Organochlorine Chemical Analysis and Lipid Content ....................................................... 18


H4IIE Rat Hepatoma Cell Bioassay ........................................................................................ 19


EROD Activity............................................................................................................................. 21


Fish Health Indicators ...................................................................................................................... 21


General Histopathological Analyses ..................................................................................... 21


Quantitative Organism-Level Indicators ............................................................................... 21


Macrophage Aggregates ........................................................................................................ 21


Reproductive Indicators ................................................................................................................... 21


Gonadal Histopathology .......................................................................................................... 21


Vitellogenin ................................................................................................................................ 22

vi Environmental Contaminants and their Effects on Fish 

Data Set Composition and Statistical Analyses ........................................................................... 23


Results and Discussion.............................................................................................................................. 24


Geographic Distribution and Demographic Characteristics of the Fish Collected................. 24


Accumulative contaminants, H4IIE Bioassay, and EROD Activity ............................................. 28


Elemental Contaminants ................................................................................................................... 28


Arsenic ....................................................................................................................................... 28


Selenium..................................................................................................................................... 30


Mercury ...................................................................................................................................... 31


Lead..... ........................................................................................................................................ 40


Cadmium..................................................................................................................................... 41


Zinc...... ........................................................................................................................................ 42


Copper.. ....................................................................................................................................... 43


Chromium and Nickel ............................................................................................................... 43


Organochlorine Chemicals............................................................................................................... 45


DDT and its primary metabolites ............................................................................................ 45


Cyclodiene pesticides: ............................................................................................................. 50


Chlordane and heptachlor.............................................................................................. 50


Dieldrin .............................................................................................................................. 50


Endrin.... ............................................................................................................................. 51


Other Organochlorine Compounds ........................................................................................ 51


Mirex.... .............................................................................................................................. 51


Toxaphene ......................................................................................................................... 51


Hexachlorocyclohexanes (HCH) ................................................................................... 52


Hexachlorobenzene (HCB) ............................................................................................. 52


Total PCBs, H4IIE-Derived Dioxin Equivalents, and EROD Activity ............................................ 52


Total PCBs .................................................................................................................................. 52


H4IIE Bioassay .......................................................................................................................... 53


Ethoxyresorufin O-Deethylase (EROD) Activity ................................................................... 53


EROD in Bass .................................................................................................................... 56


EROD in Carp .................................................................................................................... 57


EROD in Largescale Sucker ........................................................................................... 57


EROD in Other Fishes ...................................................................................................... 59


Accumulative Contaminants, H4IIE, and EROD Activity: Summary ........................................... 59


Fish Health Indicators ....................................................................................................................... 60


Organism-Level Indicators ...................................................................................................... 60 


External Gross Lesions ................................................................................................... 60


Health Assessment Index............................................................................................... 60


Condition and Organosomatic Indices ........................................................................................... 62


Condition and Organosomatic Indices in Bass........................................................... 65


Condition and Organosomatic Indices in Carp ........................................................... 67


Condition and Organosomatic Indices in Largescale Sucker .................................. 67


Cellular and Histopathological Indicators ............................................................................ 68


MAMM .............................................................................................................................. 68


MEANAREA ...................................................................................................................... 71


TISSOC............................................................................................................................... 73


Fish Health Indicators: Summary .................................................................................................... 74


Reproductive Biomarkers................................................................................................................. 80


Gonadal Histopathology .......................................................................................................... 80

Contents vii


Female Bass .............................................................................................................................. 80


Male Bass .................................................................................................................................. 83


Female Carp ............................................................................................................................... 84


Male Carp................................................................................................................................... 86


Female Largescale Sucker...................................................................................................... 87


Male Largescale Sucker ......................................................................................................... 89 


Reproductive Biomarker: Summary................................................................................................ 90 


Spatial patterns in contaminant concentrations and biomarker responses ........................... 93


Geographic Summaries ........................................................................................................... 93 


Upper Columbia River (UCR) .......................................................................................... 93


Snake River (SR) .............................................................................................................. 96


Middle Columbia River (MCR)........................................................................................ 98


Lower Columbia River (LCR)......................................................................................... 101


Correlations Between Contaminant Concentrations and Biological Endpoints .......... 102


Summary and Conclusions...................................................................................................................... 103


References................................................................................................................................................. 104


Appendix 1. ................................................................................................................................................ 119


Appendix 2. ................................................................................................................................................ 123


Figures 

1. Map of the Columbia River Basin.......................................................................................................... 3


2. 	Map of land ownership in the Columbia River Basin including government and private land 


and sites sampled in 1997........................................................................................................... 4


3. 	Concentrations of arsenic (As) and selenium (Se) by station and taxon in whole body fish 


composite samples collected in the Columbia River Basin in 1997 .................................. 30


4. 	 Concentrations of mercury (Hg) by station and taxon in whole body fish composite samples 


collected in the Columbia River Basin in 1997 ...................................................................... 40


5. 	 Concentrations of lead (Pb) and cadmium (Cd) by station and taxon in whole body fish com­


posite samples collected in the Columbia River Basin in 1997 .......................................... 40


6. 	 Concentrations of zinc (Zn), copper (Cu), chromium (Cr), and nickel (Ni) by station and taxon 


in whole body fish composite samples collected in the Columbia River Basin in 1997 . 42


7. 	 Weighted geometric mean concentrations of p,p’-DDT, DDE, and DDD by station in whole 


body fish composite samples collected in the Columbia River Basin in 1997 ................. 45


8. 	 Concentrations of p,p’-DDE, toxaphene, total chlordanes, and dieldrin by station and taxon in 


whole body fish composite samples collected in the Columbia River Basin in 1997 ..... 46


9. 	 Weighted geometric mean concentrations of chlordane-related compounds by station in 


whole body fish composite samples collected in the Columbia River Basin .................. 49


10. 	Concentrations of total PCBs and H4IIE bioassay-derived TCDD-EQ by station and taxon in 


whole body fish composite samples collected in the Columbia River Basin in 1997 ..... 52


11. 	Hepatic microsomal EROD activity by station in female and male bass, carp, and largescale 


sucker collected in the Columbia River Basin in 1997......................................................... 57


12. 	Health assessment index (HAI) score by station in bass, carp, and largescale sucker col­


lected in the Columbia River Basin in 1997............................................................................ 65


13. 	Fish health indicators by station in female and male bass collected in the Columbia River 


Basin in 1997............................................................................................................................... 68

viii Environmental Contaminants and their Effects on Fish 

14. 	Fish health indicators by station in female and male carp collected in the Columbia River 


Basin in 1997............................................................................................................................... 71


15. 	Fish health indicators by station in female and male largescale sucker collected in the 


Columbia River Basin in 1997................................................................................................... 71 


16. 	Splenic macrophage aggregate parameters by station in female and male bass collected in 


the Columbia River Basin in 1997 ............................................................................................ 73


17. 	Splenic macrophage aggregate parameters by station in female and male carp collected in 


the Columbia River Basin in 1997 ............................................................................................ 75


18. 	Splenic macrophage aggregate parameters by station in female and male largescale sucker 


collected in the Columbia River Basin in 1997 ...................................................................... 78


19. Gonadal stages in female fish species ............................................................................................ 81


20. Gonadal stages in male fish species ................................................................................................ 82


21. 	Gonadal stage proportions by taxon and gender in bass, carp, and largescale sucker col­


lected in the Columbia River Basin in 1997............................................................................ 83


22. 	Gonadal stage proportions by station in female and male bass collected in the Columbia 


River Basin in 1997..................................................................................................................... 84


23. 	Reproductive health indicators by station in female and male bass collected in the Columbia 


River Basin in 1997..................................................................................................................... 86


24. 	Gonadal stage proportions by station in female and male carp collected in the Columbia 


River Basin in 1997..................................................................................................................... 89


25. 	Reproductive health indicators by station in female and male carp collected in the Columbia 


River Basin in 1997..................................................................................................................... 90


26. 	Gonadal stage proportions by station in female and male largescale sucker collected in the 


Columbia River Basin in 1997................................................................................................... 91 


27. 	Reproductive health indicators by station in female and male largescale sucker collected in 


the Columbia River Basin in 1997 ............................................................................................ 92


28. 	Maximum concentrations of mercury, selenium, and lead in composite samples of whole 


fish. ............................................................................................................................................... 95


29. 	Mean hepatic ethoxyresorufin O-deethylase (EROD) activity in bass, carp, and largescale 


sucker)......................................................................................................................................... 96


30. Plasma vitellogenin in male bass, carp, and largescale sucker.................................................. 97


31. 	Maximum concentrations of total DDT, toxaphene, and total chlordanes, in composite 


samples of whole fish ............................................................................................................... 99


32. Maximum concentrations of PCBs and TCDD-EQ in composite samples of whole fish... ..... 100


Tables 

1. National Wildlife Refuges located in the Columbia River Basin.. ................................................... 7


2. 	 Selected protected species identified as having special status by various agencies within 


the Columbia River Basin ........................................................................................................... 8


3. Stations sampled in 1997 and collection date in the Columbia River Basin ............................... 12


4. Methods incorporated into the Columbia River Basin in 1997 ...................................................... 14


5. 	 Organochlorine chemical and elemental contaminants measured in whole body fish compos­


ite samples .................................................................................................................................. 15


6. 	 Monitoring and assessment strategy for polycyclic aromatic and polyhalogenated hydrocar­


bons.............................................................................................................................................. 17


7. 	 Detection limits and results of quality assurance for elemental contaminants analyzed in 


whole body fish composites from the Columbia River Basin ............................................. 19


8. Nominal limits of detection and results of quality assurance for organochlorine chemicals 
Contents ix 

analyzed in whole body fish composites collected from the Columbia River Basin ...... 20


9. Fish species collected from the Columbia River Basin in 1997. ................................................... 24


10. 	Number of fish collected organized by species, station, and gender in the Columbia River 


Basin in 1997. .............................................................................................................................. 26


11. Lengths, weights, and ages of bass collected in the Columbia River Basin in 1997 ................ 27


12. Lengths, weights, and ages of common carp collected in the Columbia River Basin in 1997 28


13. 	Lengths, weights, and ages of largescale suckers collected in the Columbia River Basin in 


1997 .............................................................................................................................................. 29


14. 	Occurrence and censoring concentrations for elemental contaminants in composite 


samples of whole fish from the Columbia River Basin in 1997........................................... 31


15. 	Geometric mean, minimum, and maximum concentrations of elemental contaminants in fish 


collected in the Columbia River Basin in 1997 ...................................................................... 32


16. 	Spatial trends of chemical contaminants in fish collected in the Columbia River Basin 


in 1997 .......................................................................................................................................... 35


17. 	Historical trends of chemical contaminants in fish collected from NCBP stations in the 


Columbia River Basin ................................................................................................................ 36


18. 	Occurrence of organochlorine chemical residues in composite samples of whole fish in the 


Columbia River Basin in 1997 ................................................................................................... 44 


19. 	Geometric mean, minimum, and maximum concentrations of organochlorine chemical con­


taminant in fish from stations in the Columbia River Basin in 1997................................... 47


20. 	 Results of preliminary analysis-of-variance investigating the effects of various factors on 


biomarker responses in carp, bass, and largescale sucker in the Columbia River Basin 


in 1997 .......................................................................................................................................... 54


21. 	Geometric mean and range of microsomal EROD activities in fish collected in the Columbia 


River Basin in 1997..................................................................................................................... 58


22. 	Number and location of external lesions identified on fish collected in the Columbia River 


Basin in 1997 ............................................................................................................................... 61


23. 	Distribution of Health Assessment Index scores among bass, common carp, and largescale 


sucker collected in the Columbia River Basin in 1997......................................................... 63


24. 	Arithmetic mean of condition factor by station, number of samples, minimum, maximum, and 


standard error in the target species collected in the Columbia River Basin in 1997 ..... 66


25. 	Arithmetic mean of hepatosomatic index by station, number of samples, minimum, maxi­


mum, and standard error in bass collected in the Columbia River Basin in 1997........... 69


26. Arithmetic mean of splenosomatic index by station, number of samples, minimum, maximum, 

and standard error in the target species collected in the Columbia River 


Basin in 1997 ............................................................................................................................... 70


27. 	Arithmetic mean of macrophage aggregate density by station, number of samples, minimum, 


maximum, and standard error in the target species collected in the Columbia River 


Basin in 1997 ............................................................................................................................... 72


28. 	Mean age-adjusted station means for splenic macrophage aggregate parameters 


in bass .......................................................................................................................................... 74


29. 	Arithmetic mean of macrophage aggregate area by station, number of samples, minimum, 


maximum, and standard error in the target species collected in the Columbia River 


Basin in 1997 ............................................................................................................................... 76


30. 	Arithmetic mean of percent of splenic tissue occupied by macrophage aggregates by sta­


tion, number of samples, minimum, maximum, and standard error in the target species 


collected in the Columbia River Basin in 1997 ...................................................................... 79


31. 	Arithmetic mean of gonadosomatic index by station, number of samples, minimum, maxi­


mum, and standard error in the target species collected in the Columbia River Basin in 


1997 .............................................................................................................................................. 85


32. Arithmetic mean of vitellogenin by station number of samples, minimum, maximum, and 
x Environmental Contaminants and their Effects on Fish 

standard error in fish collected in the Columbia River Basin in 1997 ............................... 87


33. 	Arithmetic mean of percent atresia by station, number of samples, minimum, maximum, and 

standard error in female fish collected in the Columbia River Basin in 1997 .................. 88 

34. Summary of chemical and biological indicator results, by sub-basin and station ................... 94


35. 	Statistically significant Spearman Rank correlations between biomarkers and 

contaminants ............................................................................................................................ 103 

Appendix 1. Lengths, weights, and ages of non-target species collected in the Columbia River 

Basin in 1997 ............................................................................................................................. 120 

Appendix 2. 	 Fish health indicators for non-target species collected in the Columbia River Basin 

in 1997 ........................................................................................................................................ 124 

Conversion Factors 

Multiply By To obtain 

Length 

centimeter (cm) 0.3937 inch (in) 

millimeter (mm) 0.03937 inch (in) 

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi) 

Area 

square kilometer (km2

) 0.3861 square mile (mi) 

cubic kilometer (km3

) 0.2399 cubic mile (mi3) 

Volume 

milliliter (mL) 0.03381 fl uid ounce (fl . oz) 

liter (L) 1.057 quart (qt) 

liter (L) 0.2642 gallon (gal) 

cubic meter (cm3

) 0.0002642 million gallons (Mgal) 

Mass 

kilogram (kg) 2.205 pound, avoirdupois (lb) 

Concentration 

microgram per gram (μg/g) = part per million (ppm; 106

) 

nanogram per gram (ng/g) = part per billion (ppb; 109

) 

picogram per gram (pg/g) = part per trillion (pptr; 1012) 

milligram per millimeter (mg/mL) = part per thousand (ppt; 103

) 

milligram per liter (mg/L) = part per million (ppm; 106

) 

microgram per liter (μg/L) = part per billion (ppb; 109

) 

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

 °F=(1.8×°C)+32 

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

 °C=(°F-32)/1.8 
Abstract 1 

Biomonitoring of Environmental Status and Trends (BEST) 

Program: Environmental Contaminants and their Effects 

on Fish in the Columbia River Basin 

By Jo Ellen Hinck1, Christopher J. Schmitt1, Timothy M. Bartish2, Nancy D. Denslow3, Vicki S. Blazer4, Patrick 

J. Anderson5

, James J. Coyle2, Gail M. Dethloff6, and Donald E. Tillitt1 

Abstract 

This project examined and analyzed 560 fish representing 

eight species collected from 16 stations in the Columbia River 

Basin (CRB) from September 1997 to April 1998. Ten of the 

16 sampling locations were historical National Contaminant 

Biomonitoring Program (NCBP) sites where organochlorine 

and elemental contaminants in fish had been monitored from 

1969 through 1986. Five sites were co-located at U.S. Geological Survey (USGS)-National Stream Quantity Accounting Network (NASQAN) stations at which water quality is 

monitored. The sampling location at Marine Park in Vancouver, Washington did not correspond to either of the established 

monitoring programs. Eight of the sampling locations were 

located on the Columbia River; three were on the Snake River, 

two were on the Willamette River, and one site was on each of 

the Yakima, Salmon and Flathead Rivers. 

Common carp (Cyprinus carpio), black bass (Micropterus sp.), and largescale sucker (Catostomus macrocheilus) 

together accounted for 80% of the fish sampled during the 

study. Fish were weighed and measured then field-examined 

for external and internal lesions, and liver, spleen, and gonads 

were weighed to compute somatic indices. Selected tissues 

1

U.S. Geological Survey, Columbia Environmental Research Center 

(CERC), 4200 New Haven Road, Columbia, MO 65201. 

2

U.S. Geological Survey, BEST Program, Fort Collins Science Center 

(FORT), 2150 Centre Avenue, Building C, Fort Collins, CO 80526. 

3

Protein Chemistry and Molecular Biomarkers Laboratory, P.O. Box 

100156 Health Center, University of Florida, Gainesville, FL 32610. 

4

U.S. Geological Survey, Leetown Science Center (LSC), 1700 Leetown 

Rd., Kearneysville, WV 24530. 

5

Johnson Controls, c/o U.S. Geological Survey, Fort Collins Science Center 

(FORT), 2150 Centre Avenue, Building C, Fort Collins, CO 80526. 

6

AScI Corporation, c/o U.S. Geological Survey, Columbia Environmental 

Research Center (CERC), 4200 New Haven Road, Columbia, MO 65201. 

and fluids were obtained and preserved for analysis of fish 

health and reproductive biomarkers. Composite samples of 

whole fish from each station were grouped by species and gender and analyzed for persistent organic and inorganic contaminants and for dioxin-like activity using the H4IIE rat hepatoma 

cell bioassay. 

Several contaminants were measured at concentrations 

that exceeded wildlife guidelines or thresholds and have been 

previously identified as chemicals of concern in the CRB. 

Concentrations of lead (>0.4 μg/g ww) in the upper Columbia River, selenium (>0.6 μg/g ww) in the lower Salmon 

and middle Columbia Rivers, and mercury (>0.1 μg/g ww) 

throughout the basin exceeded one or more wildlife criteria in 

composite fish samples. One or more fish samples from all 

stations except those in the upper CRB had concentrations of 

total DDT (>0.15 μg/g ww) that could be potentially harmful to piscivorous wildlife. Other organochlorine pesticide 

concentrations did not exceed criteria or were isolated to fish 

samples from a single sampling location. Concentrations 

of total PCBs (>0.11 μg/g ww) and TCDD-EQs (>5 pg/g) 

exceeded wildlife guidelines in fish samples from the middle 

and lower Columbia sub-basins, and ethoxyresorufin O-deethylase (EROD) activity was also elevated in fish samples at 

many of the same stations. However, trend analysis reflected 

decreasing or stable concentrations of total PCBs, p,p’-DDE, 

mercury, selenium, and lead in fish samples at stations where 

historical data were available. 

Geographic differences for the biomarkers support that 

fish in the CRB were exposed to contaminants although spatial 

trends were not apparent. The variation in biomarker results, 

including spleen and liver size, concentrations of vitellogenin, 

and presence of ovotestes, demonstrates the necessity to 

evaluate multiple species. Several male bass collected near 

Lewiston, Idaho and Warrendale, Oregon were identified as 

having ovotestes, a condition that may be caused by many factors including exposure to environmental contaminants. Male 

bass, carp, and sucker containing low concentrations of vtg 
2 Environmental Contaminants and their Effects on Fish 

were common in the CRB, but comparatively high concentrations were measured only in males from Creston, Montana, 

Grand Coulee, Washington, and Pasco, Washington. Results 

of this study indicate that some organochlorines and metals 

remain at concentrations of concern for CRB fish, and biomarker responses are consistent with contaminant exposure in 

fish at specific locations within the CRB. 

Introduction 

The Columbia River, including major tributaries, is the 

most important economic driver in the Pacific Northwest. 

This region which utilizes the river for transportation, irrigation, food, electrical power, recreation, and more. The Columbia River system also supports numerous extractive industries 

including mining, timber, rangelands, and commercial fishing. 

These uses and demands on the river have affected water 

and habitat quality and have resulted in listings of impaired 

waters, fish consumption advisories, and threatened species. 

Although numerous federal and state programs have investigated contaminants and water quality throughout the Columbia River Basin (CRB), adverse impacts from environmental 

contaminants to fish within this system are poorly understood 

(Schneider, 2002). Grazing, logging, mining, agriculture, 

irrigation, and industrial and urban land uses have all been 

associated with degraded water quality in the CRB (Joy and 

Patterson, 1997; Rinella and others, 1993; Schneider, 2002; 

Wentz and others, 1998; Williamson and others, 1998). 

We studied the Columbia River and several of its largest 

tributaries during fall 1997 and early spring 1998 as part of the 

Biomonitoring of Environmental Status and Trends (BEST) 

Program’s large river monitoring activities. The BEST 

Program is unique among national monitoring programs with 

its emphasis on characterizing the effects of environmental 

contaminants on the health of the fish and their supporting 

habitat. BEST accomplishes this through the application of 

both chemical concentration measurements and by evaluating the physiological, morphological, and histopathological 

responses of contaminant exposure by the organism. The 

primary objective of our study was to document the occurrence and distribution of contaminants and their effects on fish 

in the CRB, and to evaluate the potential risk represented by 

these contaminants to other biota. Secondary objectives were 

to compare biomonitoring results from the CRB to other major 

river systems in the U.S., and to further define benchmarks 

for the quantification of long-term trends and interpretation of 

biomarker results. These latter objectives were achieved by 

building on the results of similar investigations conducted in 

the Mississippi River Basin (MRB) in 1995 (Schmitt, 2002a) 

and the Rio Grande Basin (RGB) in 1997 (Schmitt and others, 2004). Together, the 1997 projects were also designed to 

evaluate the compatibility of the BEST large rivers component 

with the USGS National Stream Quantity Accounting Network (NASQAN) program, which monitors concentrations 

of dissolved pesticides and other constituents in the waters of 

large U.S. rivers (Hooper and others, 2001). In addition, 1997 

fish concentrations were compared to historical and contemporaneous data sets from the basin (Lower Columbia River 

Estuary Partnership (LCREP), 1991; Maccoy, 2001; Schmitt 

and others, 1999b; Tetra Tech Inc., 1996; U.S. Environmental 

Protection Agency (USEPA), 2002a). 

Data for the 1997 CRB study are reported in this document and have been incorporated into an interactive national 

database at: <www.cerc.usgs.gov/data/best/search/index.htm>. 

Results from this study, together with those from similar investigations conducted in other river basins, will help resource 

managers and scientists assess contaminant impacts on fish 

and wildlife and human consumers of those fish, and will 

identify areas within the CRB that warrant further investigation of contaminant threats. 

Columbia River Basin Overview 

Hydrology and Environmental Setting 

The Columbia River is the largest river of the Pacific 

Northwest and the fourth largest river in the U.S. The CRB 

was formed during the last ice age 12,000-19,000 years ago 

when ice dams repeatedly failed, forming the general route of 

the present day river. The river originates at Columbia Lake 

in the Rocky Mountains of British Columbia, flows for 1,214 

miles (mi), and drains approximately 259,000 square miles 

(mi2). Fifteen percent (39,000 mi2) of the CRB is located 

within Canada. The average annual runoff at the mouth of 

the Columbia River is 198 million acre-feet with average year 

round flows of 275,000 cubic feet per second, second only to 

the Missouri-Mississippi River system. 

The major tributaries of the Columbia River in the U.S. 

include the Snake, Pend Oreille, Bitterroot, Clark Fork, Willamette, Deschutes, Kootenai, Yakima, Flathead, Salmon, 

and Spokane Rivers (Fig. 1). The Snake River is the largest 

tributary of the Columbia River, flowing 1,038 mi from its 

headwaters in Yellowstone National Park in Wyoming to its 

confluence with the Columbia in southern Washington. The 

Willamette, the second largest CRB tributary, is the 13th largest river in the contiguous U.S. in terms of stream flow (Kammerer, 1990) and provides approximately 15% of the Columbia’s annual discharge (Bastasch, 2002). There are numerous 

agricultural waterways and natural streams that drain agricultural lands of central Washington, although the Yakima 

River is one of the dominant agricultural systems. The lower 

Columbia River has salt water intrusion 23 mi upstream from 

the mouth, and tidal influences can extend 146 mi upstream to 

the Bonneville Dam. 

The CRB has a diverse ecology that ranges from temperate rain forest to arid steppes and has a complex matrix 
Introduction 3 

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Upper Columbia River stations 

Snake River stations 

Midddle Columbia River stations 

Lower Columbia River stations 

Major Dams 

Major Cities 

BEST CRB Stations: 

$

Columbia River Hydrology 

Columbia River Basin (CRB) 

Figure 1. Map of the Columbia River Basin including state boundaries, major cities, major rivers and tributaries, and sites sampled in 

1997 (March/April 1998 for Vancouver, Washington (506) and Beaver Army Terminal, Oregon (501)). See Table 3 for station descriptions. 

of mountains, high plateaus, deserts, river valleys, and deep 

gorges. There are nine ecological provinces located within the 

CRB (Bailey, 1995). The Intermountain Semi-Desert Province 

is the largest ecoregion which includes the plains and plateaus 

of the Columbia and Snake Rivers and the Wyoming Basin 

and is characterized as semiarid with cool temperatures. The 

average annual precipitation ranges from <10-20 inches (in), 

and the average annual temperature is approximately 50°F. 

The chief vegetation in this ecoregion has historically been 

sagebrush with short grasses (Bailey, 1995). The second largest province is the Middle Rocky Mountain Steppes followed 

by the Cascade mixed/Coniferous Forest Province, and the 

Southern and Northern Rocky Mountain Steppes. These provinces are generally characterized as mixed evergreen-deciduous forest with much colder temperatures and greater amounts 

of precipitation. The remaining ecoregions, including the 

Sierran Steppe, the Pacific Lowlands, and the Great PlainsPalouse Dry Steppes, only have a portion of their area located 

within the CRB (Bailey, 1995). 

Three distinct air mass types including moist marine air 

from the west, dry continental air from the east and south, and 

dry, cold artic air from the north influence the CRB (Ferguson, 

1999; Quigley and others, 1997). Most precipitation occurs 

during the winter except in the far eastern and southern areas 

of the basin, which receive the most of their precipitation during the summer (Ferguson, 1999). Temperature and precipitation varies throughout the basin depending on the elevation 

and location of mountain ranges. Precipitation ranges from 

6 in per year in the arid and semi-arid regions to 150 in per 

year in the eastern Cascade Mountains. Most of the basin is 

influenced by a rain shadow effect from the Cascade Mountains. One exception is Columbia Gorge area, which allows 

moist air to pass through. Arctic air is blocked by mountain 

ranges in British Columbia; however, some artic air masses 
enter the basin through the Columbia, Okanogan, and Pend 

Oreille valleys which results in spring and summer precipitation (Ferguson, 1999). The Columbia Plateau and Snake River 

valleys are usually the driest areas of the CRB. Water from 

rainfall or snowmelt is slowly absorbed by the arid soils which 

often results in significant runoff (Ferguson, 1999).

Land Ownership

In the U.S. portion of the CRB, the federal government 

owns >52% of the land with private land ownership at 39%, 

and the remainder of ownership is partitioned among Native 

American lands and state and local government lands (Fig. 

2) (Quigley, 1997). The U.S. Forest Service (USFS) and the 

U.S. Bureau of Land Management (USBLM) own and manage 

most of the federal lands. Approximately 24% of the USFS 

land and 10% of the USBLM lands are located in the CRB 

(Quigley, 1997). In general, USFS and USBLM administered 

lands are located in the high desert and mountainous regions 

of the basin whereas private lands are predominately located 

in river valleys and plateaus. Most private lands in the basin 

are located in the Willamette Valley, the Columbia Plateau, 

Yakima River Basin, and the Snake River Basin (Fig. 2).

Urban and Metropolitan Areas

The CRB covers approximately 8% of the U.S. land area 

and contains about 1.2% of the U.S. population (Quigley, 

1997). Thirty-one percent of the CRB population lives in 

urban areas compared to the U.S. average of 78% (Quigley, 

1997). Population density within the basin is one-third of the 

U.S. average (Quigley, 1997). The largest city in the CRB 

Figure 2. Map of land ownership in the Columbia River Basin including government and private land and sites sampled in 1997.

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Upper Columbia River stations

Snake River stations

Middle Columbia River stations

Lower Columbia River stations

BEST CRB Stations:

Major Cities

Columbia River Hydrology

Federal-State Lands and Ownership in CRB:

Federal Lands

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Private Lands

State Lands

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4 Environmental Contaminants and their Effects on Fish
5 

is Portland, with a population >500,000. Four other cities 

including Spokane, Salem, Eugene, and Boise have populations >100,000. The largest metropolitan area is the PortlandVancouver-Beaverton metropolitan area. Other metropolitan 

areas include Boise, Eugene-Springfield, Richland-Kennewick-Pasco, Spokane, Yakima, and Pocatello. The Canadian 

portion of the basin does not have any large urban or metropolitan areas; most towns have populations <10,000. 

Hydroelectric Power and Dams 

The CRB is often cited as the most hydroelectrically 

developed river system of the world. Development of the 

major dams and storage reservoirs within the CRB took place 

from the early 1900s through the 1970s for irrigation, water 

storage, electrical power, and river transportation. There are 

>150 hydroelectric projects in the basin including 18 mainstem dams on the Columbia and Snake Rivers, representing 

40% of the total hydropower production in the U.S. (Dietrich, 

1995). The U.S. Army Corps of Engineers operates nine of 

ten federal projects on the Columbia and Snake Rivers (Fig. 

1). Most federal dams on the lower Columbia and lower 

Snake Rivers are run-of-river dams that are primarily operated for power generation and navigation. Four federal dams 

(Bonneville, The Dalles, John Day, and McNary) have navigation locks that allow boats and barges to move upstream as 

far as Richland, Washington and Lewiston, Idaho. Five of the 

federal dams are storage dams of which the Grand Coulee is 

the largest. 

The U.S. Bureau of Reclamation (USBOR) has been 

operating in the CRB since 1904. The USBOR has been 

involved with >39 projects, including 72 dams, dikes, and 

diversions and >4,700 mi of canals (Bonneville Power 

Administration (BPA), 2001). USBOR delivers water to 175 

irrigation districts within the Pacific Northwest region, which 

includes approximately 2.9 million acres of irrigated crops 

with an estimated annual crop value of $2.2 billion (BPA, 

2001). The largest of these projects is known as the USBOR 

Columbia River Project, which diverts 2.7 million acre-feet 

of water to irrigate 672,000 acres of land mainly within the 

Columbia Plateau (BPA, 2001). The key structure of the 

Columbia Project is the Grand Coulee Dam which is located 

on the main stem of the Columbia River. Extensive irrigation including 300 mi of main canals, approximately 2,000 

mi of laterals, and 3,500 mi of drains and wasteways extend 

southward from the Columbia Plateau to Pasco and Richland, 

Washington (BPA, 2001; Schneider, 2002). 

The Yakima Project, another large USBOR irrigation 

project, irrigates approximately 464,000 acres for growing grains, alfalfa hay, silage, dry beans, fruits, sugar beets, 

potatoes, sweet corn, and many specialty crops (BPA, 2001). 

Releases from both the Columbia and Yakima projects are 

made in July and August to ensure adequate water in the lower 

Introduction 

Columbia River for fish migration (BPA, 2001). Other smaller 

irrigation projects in the CRB are the Boise Project in Idaho 

and Oregon, the Mindoka Project in Idaho, the Deschutes Project in Oregon, and the Palisades Project in Idaho and Wyoming (Bastasch, 2002; BPA, 2001; Schneider, 2002). Much of 

the water diverted for irrigation is routed back to the river as 

irrigation return flows, which introduce nutrients and contaminants into streams and rivers. Several large-scale programs 

(Bi-State Water Quality Program, National Water Quality 

Assessment (NAWQA), and NASQAN) and focused studies in 

the CRB have cited agriculture and agriculture return flows as 

contributing to degraded water quality; however, the extent of 

the degradation is not well understood (Schneider, 2002). 

Dams on the Columbia and Snake Rivers are noted for 

blocking anadromous fish migration and are contributors to 

degraded water quality (Schneider, 2002). Most often these 

dams affect water temperature, increase dissolved gases 

(mostly nitrogen), modify flow regimes, and are associated 

with industrial spills. Both water releases and periodic dredging allows for the navigation of barges up and down the rivers. 

Dredging operations have also contributed to degraded water 

quality by releasing contaminants from sediment (Schneider, 

2002). 

Water Quality 

Impairments 

Waters (rivers, streams, lakes) that do not meet defined 

water quality standards are listed as impaired. Section 303(d) 

of the Clean Water Act requires each state to assess all surface 

waters and list those that are impaired. There are hundreds 

of water bodies throughout the CRB on the 1998 303(d) list, 

and most are located on small tributaries and are included for 

temperature, dissolved gas, and flow modifications impairments. Other common impairments include dissolved oxygen, 

bacteria, pathogens, sediments, and pH. The review of 1998 

303(d) listed waters for this report focused only on those listings associated with rivers or reservoirs related to the Columbia River and its major tributaries. The lower Columbia River 

has numerous impairments due to DDT (2,2-bis (p-chlorophenyl)-1,1,1-trichloroethane), DDE (2,2-bis (p-chlorophenyl)-

1,1-dichloroethylene), dieldrin, phthalates, and PCB (polychlorinated biphenyl) (USEPA, 2002b). DDT and DDE are 

also noted for impairing reaches throughout the Yakima, lower 

Willamette, lower Snake, Walla Walla, and Pudding Rivers, 

and numerous creeks and reservoirs that are predominantly 

in agricultural areas. Dieldrin impairments are also common 

in agriculture areas in the lower Columbia River, middle and 

lower Willamette River, Yakima River, Owyhee River, Palouse 

River, and many creeks (USEPA, 2002b). Impairments due 

to PCBs occur in the lower Columbia (mouth to Bonneville 

Dam), Lower Willamette, Yakima, and lower Spokane Rivers (USEPA, 2002b). Nutrient impairments, which include 
6 Environmental Contaminants and their Effects on Fish 

nitrates and phosphorus, are widely distributed throughout the 

CRB usually in smaller watersheds and on larger rivers including the lower Willamette, Clark Fork, Spokane, Umatilla, and 

the Malheur Rivers (USEPA, 2002b). A single dioxin impairment for the Columbia Slough near the Willamette River in 

Portland is listed for the CRB (Oregon Department of Environmental Quality (ODEQ), 2000). Most metal impairments 

are associated with mining activities and urban areas such as 

Portland and Spokane (USEPA, 2002b). Arsenic (As) impairments occur from the mouth of the Columbia River to McNary 

Dam (USEPA, 2002b), and mercury (Hg) impairments occur 

on the Yakima, Owyhee, Columbia (Roosevelt Lake to the 

international border), and Snake Rivers (Washington border to 

the Salmon River) (USEPA, 2002b). 

Fish Consumption Advisories 

Fish consumption advisories are designed to protect 

human health and are also good indicators of water quality because most advisories are issued after assessing results 

from fish tissues. The USEPA National Listing of Fish and 

Wildlife Advisories (NLFWA) database was queried for all the 

states associated with the CRB (USEPA, 2003a). There were 

>30 fish consumption advisories in the CRB during the early 

1990s through 1998. The advisory review for this report only 

included those associated with rivers or reservoirs of the major 

tributaries. Mercury, dioxins, and PCBs were the most common contaminants associated with these advisories. 

The mainstem of the Columbia River is associated with 

two fish consumption advisories. The first advisory for DDT, 

dioxins, and PCBs for all freshwater fish is located from the 

mouth of the Columbia River to Bonneville Dam (USEPA, 

2003a). The second advisory, issued in 2000 for PCBs in 

shellfish and crayfish, is located above Bonneville Dam at 

river mile 147 (USEPA, 2003a) and is associated with the 

Bradford Landfill. Public health officials investigated contamination possibilities at this site in the early 1990s (Schneider, 

2002), and it was determined that electrical equipment buried 

at the site contaminated soil and sediments in a localized area. 

The Willamette River has several advisories for As, creosote, pentachlorophenol (near a wood treatment site located 

in Portland), Hg, and PCBs (USEPA, 2003a). The source of 

the Hg is thought to come from natural volcanic and mineral 

sources in the headwaters of the river and from a number of 

point sources along the river (Bastasch, 2002). The Willamette River advisories were revised in 2000 to include all fish 

for PCBs, organoclorinated pesticides, and dioxins (USEPA, 

2003a). The Snake River is under a Hg advisory for all fish by 

the state of Oregon (USEPA, 2003a). This advisory extends 

from the Oregon/Washington border to the point at which the 

river leaves Idaho below the town of Adrian. An advisory for 

the Yakima River was issued for DDT and DDE in all bottomdwelling fish. This advisory includes the Yakima River and 

all its tributaries and agricultural drains between the city of 

Yakima and its confluence with the Columbia River (USEPA, 

2003a). The Spokane River is under fish advisories for lead 

(Pb) and PCBs (USEPA, 2003a). 

There are two mainstem reservoirs with advisories. The 

advisory for Brownlee, located on the Snake River, was issued 

in 1994 because of Hg in common carp (Cyprinus carpio, 

henceforth carp) and game fish (USEPA, 2003a). Two advisories are listed for Lake Roosevelt. The first advisory, issued 

in 1994 for dioxins in whitefish (Coregonus clupeaformis) 

(USEPA, 2003a), has been attributed to a pulp mill in British 

Columbia (Schneider, 2002). A Hg advisory was issued for 

walleye (Stizostedion vitreum) in 2002 after high concentrations were reported in fish from Lake Roosevelt (Munn, 2000; 

Munn and Short, 1997). 

U.S. Department of the Interior (DOI) Resources 

at Risk from Contaminants in the CRB 

Thirty National Wildlife Refuges (NWRs) managed by 

the USFWS are located in the CRB. BEST sampling sites 

were located within 30 km of seven NWRs (Table 1). Multiple species within the CRB have been designated as having special status (that is, threatened, endangered, sensitive), 

although this designation is complicated by federal and state 

authorities using a variety of status listings. Hundreds of plant 

and animal species within the CRB have been listed by a variety of agencies, and several species are commonly recognized 

(Table 2) (USFWS, 2004). 

Extant Sources of Information on Contaminants 

in the CRB 

National Contaminant Biomonitoring Program 

The National Contaminant Biomonitoring Program 

(NCBP), formally the National Pesticide Monitoring Program 

(NPMP), was maintained by the USFWS from the late 1960s 

through the 1980s. The main objective of this program was 

to document temporal and spatial trends of organochlorine 

and elemental concentrations in fish (Schmitt and others, 

1999b). By the mid-1980s, the program reported concentrations of many persistent contaminants such as organochlorine 

pesticides, PCBs, and Hg were decreasing in whole body fish 

samples. Historical concentration data are available for fish 

samples, including carp, largescale sucker (Catostomus macrocheilus), bass (Micropterus sp.), and northern pikeminnow 

(Ptychochelius oregonesis), collected at 10 CRB sites (Stations 

117, 98, 41, 43, 42, 96, 97, 44, 46, and 45; Table 3) from 1969 

through 1986 (Schmitt and others, 1999b). These historical 

data were compared to our 1997 data to examine temporal 

trends in fish sample concentrations. 
7 

Table 1. National Wildlife Refuges (NWRs) located 

in the Columbia River Basin. BEST sampling sites 

located within 30 km of a NWR are listed. 

NWR Name BEST Site within 30 

km of NWR 

Ankeny NWR 

Baskett Slough NWR 

Camas NWR 

Cold Springs NWR 

Columbia NWR 

Conboy Lake NWR 

Deer Flat NWR 

Grays Lake NWR 

Julia Butler Hansen NWR for Station 501 

the Columbian Whitetail Deer 

Kootenai NWR 

Lee Metcalf NWR 

Lewis and Clark NWR 

Little Pend Oreille NWR 

McKay Creek NWR 

McNary NWR Station 96 

Minidoka NWR 

National Bison Range 

National Elk Refuge 

Nine-Pipe NWR 

Pablo NWR 

Ridgefield NWR Stations 505 and 506 

Saddle Mountain NWR Station 503 

Steigerwald Lake NWR Stations 502 and 506 

Swan River NWR 

Toppenish NWR Station 44 

Tualatin River NWR Station 505 

Turnbull NWR 

Umatilla NWR 

William L. Finley NWR 

National Estuary Program 

The USEPA administers the National Estuary Program 

(NEP), which was established in 1987 by amendments to the 

Clean Water Act and places responsibility for protecting estuaries to the local level. Public and private stakeholders work 

through committees to identify problems, determine actions, 

and develop implementation plans to protect estuaries and 

their natural resources. The lower Columbia River Estuary 

Plan (Plan) focused on the 146 mi of tidally influenced section of the river below the Bonneville Dam. The Plan identified toxic contaminants as an issue of concern for the overall 

health of the Columbia River estuary citing pesticides in water, 

dioxin and metals in some sediment samples, and a host of 

organic and inorganic contaminants in the tissues of fish and 

wildlife (LCREP, 1991). 

Introduction 

Columbia River Basin Fish Contaminant Survey 

This study was undertaken in 1996-1998 to evaluate the 

risks posed to members of the tribes comprising the Columbia River Intertribal Fish Commission (CRITFC) (USEPA, 

2002a). Sampling locations were selected based upon input 

from tribal members, and analytes were chosen based on 

resulsts from other studies in the CRB. Eleven species including anadromous and resident fish were collected. Whole body, 

fillet (skin off except for sturgeon samples), and egg samples 

(n=281) were collected, and composite fish tissues except for 

sturgeon samples were analyzed for a suite of 132 contaminants including 51 semi-volatile chemicals, 26 pesticides, 

18 metals, seven PCBs, 20 dioxins, and 10 furans. More 

specifically, seven Aroclors®, 13 dioxin-like PCB congeners, 

seven chlorinated dioxins, and 10 chlorinated furan congeners 

were included in the analysis. Many contaminants including various semi-volatile chemicals, pesticides, metals, and 

PCBs were not detected although analytical methods may have 

resulted in high detection limits for some PAHs and semi-volatile chemicals. Hexachlorobenzene, chlordane (and related 

compounds), and DDT and its metabolites were the most 

frequently detected pesticides. Of the seven PCB analyzed, 

Aroclor® 1254 and 1260 were the most frequently detected, 

and four were never detected. Chlorinated dioxins and furans 

were widely detected; white sturgeon (Acipenser transmontanus) had the greatest concentrations. Antimony and silver 

(Ag) were the only inorganic contaminants of the sixteen 

analyzed that were not detected. 

Contaminant Load Contributions to the Lower 

Columbia River (LCR) 

Rosetta and Borys (1996) estimated the contaminant load 

contributions to the LCR (Columbia River below Bonneville 

Dam) based on discharge volumes and concentrations reported 

by permitted point sources and extrapolating from instantaneous analytical and flow measurements. The segment of the 

LCR proximal to and downstream from Portland received the 

highest organic and metal loads. Approximately 52% of the 

waste water volume discharged to the LCR came from sewage 

treatment plants, 39% from paper and allied product manufacturers, and 8% from chemical and primary metal production. While contributing only 39% of the total flows, paper 

and allied product manufacturers added 71% of the suspended 

sediment load to the LCR. The study also identified 147 

facilities that were likely to contribute dioxins and furans to 

the river, 98 of which were discharged to either the Willamette 

or lower Columbia Rivers. 
8 Environmental Contaminants and their Effects on Fish 

Table 2. Selected protected species identified as having special status by various agencies within the Columbia River 2 Basin. 1

Quigley and others, 1997. USFWS Threatened and Endangered Species System (TESS) webpage. 


<https://ecos.fws.gov/ecos/sec/species.do> (accessed 1/6/04)


Common Name Scientific Name Designation 

White Sturgeon1 Acipenser transontanus Endangered – USFWS, State of Idaho 

Sensitive – BLM 

Pacific Lamprey 1 Lampetra tridentate Endangered – Idaho Dept of Fish and Game 

Sockeye Salmon 1 Oncorynchus nerka Endangered – USFWS (Upper Snake River in 

Idaho) 

Chum Salmon1 Oncorhynchus keta Sensitive – Oregon 

Coho Salmon1 Oncorhynchus kisutch Endangered – NMFS (petitioned) 

Costal Cutthroat Trout1 Oncorhynchus clarki clarki Threatened – NMFS 

Critical Species – Oregon Dept of Fish and 

Wildlife 

Pygmy Whitefish1 Prosopium coulteri Monitor Species – Washington 

Burbot1 Lota lota Threatened – Idaho 

Sensitive – Region 1 USFS 

Sand Roller1 Percopis transmontana Special Concern – Idaho 

Monitor Species – Washington 

Borax Lake chub2 Gila boraxobius Endangered – USFWS 

Brown pelican2 Pelecanus occidentalis Endangered – USFWS 

Bruneau Hot springsnail2 Pyrgulopsis bruneauensis Endangered – USFWS 

Columbian white-tailed deer2 Odocoileus virginianus leucurus Endangered – USFWS 

Lost River sucker 2 Deltistes luxatus Endangered – USFWS 

Mountain yellow-legged frog 2 Rana muscosa Endangered – USFWS 

Oregon chub2 Oregonichthys crameri Endangered – USFWS 

Canada Lynx 2 Lynx Canadensis Threatened – USFWS 

Lahontan cutthroat trout2 Oncorhynchus clarki henshawi Threatened – USFWS 

Northern spotted owl2 Strix occidentalis caurina Threatened – USFWS 

Piping Plover2 Charadrius melodus Threatened – USFWS 

Steller sea-lion2 Eumetopias jubatus Threatened – USFWS 

Western snowy plover2 Charadrius alexandrinus nivosu Threatened – USFWS 

Bi-State Water Quality Program 

The legislatures of Oregon and Washington along with 

contributions from port authorities and industry funded a 

four year initiative titled the Lower Columbia River Bi-State 

Water Quality Program (Tetra Tech Inc., 1996). The Bi-State 

Program focused on evaluating water quality in the Columbia 

River from the Bonneville Dam to the Pacific Ocean. One of 

the Bi-State Program initiatives was to evaluate the health of 

the river (Tetra Tech Inc., 1996). The evaluation concluded 

that there was strong evidence that many of the contaminants 

present in the LCR had the potential to have negative effects 

on wildlife. Sediments in select locations contained heavy 

metals, organochlorine pesticides, dioxins, furans, and other 

organic compounds at concentrations capable of harming 

wildlife. 

USGS National Water Quality Assessment 

(NAWQA) Program 

The NAWQA Program has conducted numerous assessments in five study units within the CRB. These study units 

include the Central Columbia Plateau (Washington and Idaho), 

upper Snake River Basin (Idaho and Wyoming), Willamette 

River Basin (Oregon), Yakima River Basin (Washington), 

and the Northern Rockies Intermontaine Basins (Washington, 

Idaho, and Montana). Pesticides were frequently detected 

below drinking water standards in ground water in the Central 

Columbia Plateau. Dieldrin, 1,2-dibromoethane (EDB), and 

1,2-dichloropropane (1,2-DCP) were found to exceed drinking 

water standards in only 2% of the wells (Williamson and others, 1998), whereas the herbicide atrazine and its breakdown 

products were detected most often in ground water. Commonly used pesticides in the Palouse subunit of the Central 

Columbia Plateau were not detected in ground water, but 10 

pesticides were detected in surface water. Nutrients have 

stimulated plant growth in streams which have contributed 

to dissolved oxygen levels below requirements by some fish 

species. Erosion has degraded habitat and mobilized sediment 

contaminated with persistent pesticides or total PCBs resulting in guidelines being exceeded at 22% of the sites sampled. 

The waterborne concentrations of agricultural pesticides (that 

is, currently used organophosphate insecticides) occasionally 

exceeded criteria for the protection of aquatic life in some 

streams. 

Concentrations of nitrate in surface water in the upper 

Snake River Basin did not exceed the drinking water standard 

but were highest downstream from agricultural areas (Clark 

and others, 1998). Pesticides were generally detected in sur­
9 

face water in the spring and early summer following seasonal 

applications; however, some pesticides were detected at low 

concentrations throughout the year. Detected pesticides in 

surface water did not exceed established water quality criteria. 

Excessive aquatic vegetation, low dissolved oxygen, and high 

water temperatures due to a combination of nutrient and sediment inputs and reduced stream flows characterize the middle 

Snake River. Pollution sources in the middle Snake River 

include discharges from fish hatcheries and municipal wastewater and agriculture irrigation returns. 

Nutrients in surface water and ground water have 

degraded water quality in the Willamette Valley (Wentz and 

others, 1998). Total phosphorus concentrations exceeded 

values recommended to prevent nuisance plant growth in 

nearly half of the streams sampled. Elevated nitrate concentrations were associated with irrigated agricultural areas. Total 

dioxin and furan concentrations in stream and lake sediments exceeded the USEPA guideline for risks to fish at two 

sites located downstream of Portland and Corvallis, Oregon, 

although tissue concentrations did not exceed the threshold for 

risks to predator fish. Banned organochlorine pesticides and 

PCBs persisted in sediment and aquatic biota from streams 

and lakes. Sediment concentrations of organochlorine pesticides exceeded USEPA guidelines for protection of aquatic 

life at 10 of 47 sites with chlordane, DDT, and their related 

constituents accounting for most exceedances. Fish tissue 

concentrations of these chemicals collected at 17 sites did not 

exceed criteria for protection of fish-eating wildlife. Chromium (Cr) and nickel (Ni) in sediment commonly exceeded 

guidelines. The highest measured sediment concentrations 

of cadmium (Cd), Pb, Ag, and zinc (Zn) were found in urban 

streams. Mercury concentrations in bed sediment were found 

to be the highest downstream from the abandoned Black Butte 

Mine located south of Eugene, Oregon. Elevated concentrations of Hg in fish have resulted in consumption advisories in 

some streams and reservoirs. 

Numerous studies in the Yakima River Basin have 

detected pesticides associated with irrigation drainwater 

throughout the basin (Ebbert and Embrey, 2002; Rinella and 

others, 1993; 1999). Pesticide studies conducted in 1999 

and 2000 detected at least 20 pesticides basin wide (Ebbert 

and Embrey, 2002). The most frequently detected herbicide 

was atrazine, whereas azinphos-methyl was the most widely 

detected insecticide. Maximum concentrations of azinphosmethyl, carbaryl, diazinon, lindane, and p,p’-DDE have 

exceeded USEPA chronic-toxicity guidelines for the protection 

of aquatic life. The highest detection frequencies and concentrations of pesticides generally occurred during irrigation 

season and in the lower reaches of the Yakima (Ebbert and 

Embrey, 2002; Rinella and others, 1999). 

Water quality issues with the northern Rocky Mountains 

Intermontane Basins study unit are mainly associated with 

mining activities and other extractive industries than from 

municipal and industrial wastes. Mining waste and tailings 

have affected surface and ground water in the watersheds of 

both the Clark Fork-Pend Oreille and Spokane Rivers (BeckIntroduction 

with, 2002; Maret and Skinner, 2000). Mine tailings in the 

study unit typically contain high concentrations of the trace 

metals such as As, Cd, copper (Cu), Pb, and Zn. Several fish 

kills in the Clark Fork River since 1984 have been attributed 

to the toxic effects of these trace metals (Maret and Skinner, 

2000). Other water quality issues include high concentrations 

of PCBs in fish tissues. Concentrations of PCBs in sportfish 

fillets collected from the Spokane River exceeded the human 

consumption criterion for edible fish tissue while concentrations of total PCBs in most rainbow trout (Oncorhynchus 

mykiss; whole body and fillets) and largescale sucker (whole 

body) samples exceeded the criterion for fish-eating wildlife 

(Maccoy, 2001). Concentrations of PCBs in fish from the 

Spokane River have remained 10 times higher than protective 

criteria for more than six years (Maccoy, 2001). 

NAWQA also assessed the occurrence and distribution of 

organochlorine pesticides and PCBs in aquatic biota as part of 

a national water quality assessment program from 1992-1995 

(Wong and others, 2000). Whole body freshwater fish were 

collected from 234 sites across the U.S. in the early 1990s. 

Wong and others (2000) concluded that organochlorine pesticides were high in agricultural regions and urban areas. 

Major Sources of Contaminants to the Columbia 

River Basin 

Air Pollution Patterns 

Air pollution patterns are typically influenced by weather 

fronts and geography. The most common patterns are temperature inversions which trap pollutants near the ground, wind 

patterns moving pollutants through the mountain passes, and 

rains depositing pollutants (Ferguson, 1999). Schoettle and 

others (1999) identified numerous pollutants of concern for the 

interior CRB including sulfur oxides, nitrogen oxides, ozone, 

small airborne particles, radionuclides, and numerous hazardous pollutants such as Hg, PCBs, and dioxins. Schoettle and 

others (1999) were able to generalize geographic distributions 

of air pollutant concentrations after assessing snowpack chemistry patterns and monitoring data. Areas west of Yellowstone 

National Park in Wyoming and a small area within Montana 

had the greatest concentrations of air pollutants (mostly 

sulfate, nitrates, and acidity) in the CRB. Collection sites at 

lower elevations had greater concentrations of these pollutants 

than high elevation snowpack sites, a pattern that was attributed to seasonal precipitation. Greater concentrations of air 

pollutants were measured in the summer rather than the winter 

when snow accumulation is greater. 
10 Environmental Contaminants and their Effects on Fish 

Agriculture 

The main agriculture centers of the CRB are along 

the lower Columbia River, the Willamette Valley, valleys 

and plateaus of the Snake River, and the Columbia Plateau. 

Approximately 7.3 million acres (using 6% of the total annual 

flow) are irrigated in the CRB, and the majority of the irrigated acreage (7.1 million acres) is in the U.S. Major crops 

include alfalfa, potatoes, mint, beets, beans, fruits, and grapes. 

The counties with the largest number of farms operating are 

located in the Willamette and Yakima sub-basins according 

to the U.S. Department of Agriculture (USDA) 1997 Agriculture census (USDA, 1997). Basins with the largest acreage in 

orchard crops were the Yakima, Willamette, and Hood River 

Basins. In 1997, 73% (80,000 acres) of orchards in Yakima 

County were treated with chemicals to control insects and 

diseases (USDA, 1997). 

The NAWQA and NASQAN programs have investigated pesticides and other agricultural related contaminants in 

surface water and ground water throughout the CRB. Toxic 

chemicals were common in water, sediments, and fish tissues, 

and concentrations of these chemicals were greater than anticipated (Schneider, 2002). Most pesticides were detected in fish 

tissues at least once (Schneider, 2002) and found in complex 

mixtures (Clark and others, 1998; Wentz and others, 1998; 

Williamson and others, 1998). Exceedences of DDT and its 

byproducts, PCBs, and other pesticides and herbicides were 

measured in many basins; however, the Yakima basin had fish 

with some of the highest concentrations of DDT measured 

in the U.S. (Rinella and others, 1993). Persistent pesticide 

loads from irrigated agricultural areas of the lower Yakima 

River Basin have long been recognized as serious impairments to water quality, and data indicate that piscivorous 

wildlife are still likely at risk from exposure to DDT, dieldrin, 

and other pesticides in Yakima River fish (Joy and Patterson, 

1997). Fish communities studied in the NAWQA basins were 

routinely degraded at urban and agriculturally influenced sites 

(Clark and others, 1998; Wentz and others, 1998; Williamson 

and others, 1998). 

Mining and Extractive Industries 

Mining was an important historical activity throughout 

the CRB. Today, most of the mining in the CRB is focused 

on metals (gold, Ag, iron (Fe), Hg, Cu, and Zn) and industrial 

minerals such as phosphate, limestone, dolomite, and perlite 

(Quigley, 1997). Aggregate mining (extraction of sand and 

gravel) is distributed throughout the basin often occurring 

near towns and waterways. Mining for metallic minerals and 

phosphates are limited to relatively small specific locations in 

the basin but are important on a national scale (Quigley, 1997). 

Phosphate deposits primarily located in the Snake River headwaters accounts for 4% of the world’s production and 12% of 

the U.S. output. Gold production in Washington, Montana, 

and Idaho accounts for 11% of the total national output, and 

Ag production in Idaho and Montana contributes 30% of the 

national output. There are numerous small heap leach fields 

throughout the basin located on or near floodplains with the 

potential of contaminating streams and rivers (Quigley, 1997). 

Other metals commonly mined in the CRB are molybdenum 

and magnesium. Twenty counties within the CRB contributed 

>90% of the non-fuel mineral production and accounted for 

<25% of the mining economy during 1980 to 1992 (Quigley, 

1997). The U.S. Bureau of Mines estimated that approximately 14,000 mines were inactive or abandoned in the CRB, 

and 190 of these sites were classified as potentially hazardous to the environment (Quigley, 1997). The NAWQA study 

units have all reported trace metal contamination from mining 

impacts (Clark and others, 1998; Wentz and others, 1998; Williamson and others, 1998). 

There are several specific mining areas that are important 

in the upper CRB. The Coeur d’Alene (CDA) River is a tributary of the Spokane River in northern Idaho. The CDA River 

and surrounding basin have been heavily contaminated by tailings from a century of Pb mining and related activities in the 

area around Kellogg, Idaho. Farag and others (1998) reported 

juvenile perch (Perca flavescans) from the CDA River basin 

have bioaccumulated metals, and metals could bioaccumulate 

to concentrations that cause physiological effects in indigenous fish (Farag and others, 1995). In another study, laboratory cutthroat trout (Oncorhynchus clarki) were fed benthic 

macroinvertebrates from the CDA River which resulted in 

reduced feeding activity, histological changes, and metallothionein induction (Farag and others, 1999). Mining activities in the CDA River basin have also resulted in Pb-related 

problems in multiple bird species (Henny and others, 1994; 

2000). The upper Clark Fork River basin in western Montana contains one of the largest ore deposits of Cu, Cd, Pb, 

manganese (Mn), and Zn and has received mining waste from 

Butte and Anaconda since 1880 (Woodward and others, 1994). 

Laboratory studies have reported tissue metal accumulation, 

physiological changes, and decreased survival and growth in 

rainbow trout fed a metal-contaminated invertebrate diet from 

the Clark Fork River (Farag and others, 1994; Woodward and 

others, 1994). 

Industrial and Municipal Sources 

The distribution, magnitude, and types of contaminants 

released in the CRB by industrial and municipal point and 

non-point sources exert both proximal and basin-wide impacts. 

To better understand these impacts and to support a more 

comprehensive analysis of our findings, records describing 

the location and types/amounts of contaminants released to 

the air (fugitive emissions) and surface waters of the CRB 

from 1990 to 1997 were reviewed. Location and discharge 

data for permitted facilities were derived from the USEPA’s 

Better Assessment Science Integrating Point and Nonpoint 

Sources (BASINS ver 3.0) analysis system (USEPA, 2001) 

and through the USEPA Envirofacts Toxic Release Inventory 
11 

(TRI) (USEPA, 2003b) and Permit Compliance System (PCS) 

(USEPA, 2003c). Information on the Comprehensive Environmental Response, Compensation, and Liability Information 

System (CERCLIS) sites, a database to archive information on 

hazardous waste and remediation efforts at Superfund sites, 

was accessed through BASINS for 1997 (USEPA, 2003d). 

Unique CERCLIS identification numbers were used to query 

the Envirofacts CERCLIS database for Record of Decisions or 

for site documentation. Summaries of point-source discharges 

were derived from BASINS data. 

The primary wastewater discharges in British Columbia 

include a Pb-Zn smelter at Trail and a pulp mill at Castlegar. 

The smelter has historically released significant quantities 

of As, Cd, Cu, Cr, Pb, Hg and Zn (Erwin and Munn, 1997; 

Schmitt and others, 2002a). The pulp mill typically releases 

organic compounds including furans, dioxins, chlorophenols, 

resin, and fatty acids (Serdar, 1997). In addition, the cities of 

Castlegar and Trail discharge treated municipal waste into the 

Columbia River. 

Industrial discharges in the U.S. portion of the basin 

cluster in and near major population centers. Facilities discharging under the National Pollution Elimination Discharge 

System (NPDES) into the Spokane River and its tributaries in 

and near Spokane, Washington include two municipal wastewater treatment works and aluminum, paper, and chemical 

production facilities. Spokane is also host to >50 industrial 

facilities including food preparation, wood and paper product 

manufacture, paint and coating operations, plastic, metal and 

electronics manufacturing operations. Several food-related 

facilities located 30 mi upstream of Twin Falls, Idaho discharged >400,000 pounds (lbs) of nitrates and ammonia into 

the Snake River. The Boise River upstream of its confluence 

with the Snake River, received >700,000 lbs of nitrates from 

a food-processing facility and ammonia from an aquaculture operation. The Snake River, after its confluence with 

the Boise River, received an additional load (160,000 lbs in 

1996) of nitrate compounds from a third food-related facility. 

Private and publicly owned hatchery operations are distributed throughout the basin, and the largest of these operations 

may produce one million pounds of fish annually. The largest 

impact of hatchery operations is phosphorus loading, which 

has contributed to the growth of aquatic vegetation, decreased 

oxygen, and increased temperature in the middle Snake watershed. Other discharges into the Snake River from 1995-1997 

include Zn (>6,000 lbs), methanol (300,000 lbs), and formaldehyde (>5,000 lbs) from a pulp and paper mill near Lewiston, 

Idaho. Facilities in the Tri-Cities of Kennewick, Richland, and 

Pasco, Washington area include food-related, chemical, mill, 

and metal operations and waste water treatment facilities. The 

U.S. Department of Energy (USDOE) Hanford site has three 

sites discharging to surface waters under NPDES permits. 

The Portland area hosts the largest and most diverse array 

of manufacturing and production facilities in the basin operating under TRI or NPDES. The Willamette Valley has >170 

facilities operating with PCS permits including wastewater 

treatment, paper, chemical, metal, lumber, and food producIntroduction 

tion facilities. The types of TRI facilities in the Portland 

area include >250 operations, comprising food, textile, mill 

works, cabinet, pulp and paper chemical printing, plastics, 

glass, ferrous and non-ferrous metal products, electroplating, machine parts, electronic and computer, motor vehicles, 

and surgical and optical manufacturing facilities. The Willamette River received discharges from a number of industrial 

facilities, including ship building operations, semi conductor 

manufacturers, and several paper mills which contributed Cu 

(16,000 lbs), manganese (43,000 lbs), nitrate chemicals (>2.8 

million lbs), and Zn (51,000 lbs) from 1995-1997. Facilities 

in the Willamette Valley, discharging >5,000 lbs of individual 

contaminants to the Willamette River include two non-ferrous 

smelter/rolling plant, three paper/pulp mills, and two wood 

products manufacturers. Industrial facilities in this area cluster 

in the urban centers of Eugene, Corvallis, Albany, and Salem. 

In the upper CRB, a paper and pulp mill discharged nitrate 

compounds (>200,000 lbs) to the Pend Oreille River, and an 

aluminum producing facility released fibrous aluminum oxide 

(>11,000 lbs) in 1997. 

Comprehensive Environmental Response, 

Compensation, and Liability Act (CERCLA -

Superfund) Site Summary 

The CRB has 102 CERCLIS sites with national priority 

list (NPL) sites located in multiple states including Idaho (4), 

Montana (2), Oregon (8), and Washington (27). The majority of these sites are clustered in three areas including Central 

Washington, Eastern Washington/Western Idaho, and the 

Portland metropolitan area. With the exception of the Hanford site, the CERCLIS sites were combined and summarized 

according to the geographic clusters. 

The Hanford site is composed of four administrative units 

(Areas 100, 200, 300, and 1100). These NPL sites are part 

of a USDOE complex 35 mi north of Richland, Washington. 

Radioactive waste, heavy metals, PCBs, and volatile organic 

compounds (VOCs) have contaminated ground water, soil, 

sludges, and/or surface water at this site. 

Eleven CERCLIS sites including eight NPL sites are 

clustered in Central Washington (northeast of Wenatchee and 

southwest of Grande Coulee). This cluster includes industrial 

(2), landfill (4), national defense (3), and mining (2) sites. 

Most sites involve ground water, soil, and sludge contamination. 

Fourteen CERCLIS sites including industrial (7), disposal 

(3), mining (3), and U.S. Army Corps of Engineers are located 

in Eastern Washington/Western Idaho. Five of the 14 sites are 

included on the NPL. Ground water, soil, sludge, and mining 

wastes are contaminated with a variety of organic and heavy 

metals. 

The Portland metropolitan area cluster (including Vancover, Washington) contains 33 CERCLIS sites (primarily 

industrial) including 11 NPL sites. These sites involve con­
12 

Table 3. Location, program of origin, and collection dates of sampling stations in the Columbia River Basin (CRB). Stations are grouped by sub-basin and ordered upstream 

to downstream. 

Station River Location Program (NASQAN Collection date(s) Latitude, Longitude number station ID) 

Upper Columbia River (UCR)

Flathead 117 Creston, MT NCBP 10/31/97-11/1/97 48°09’01.09”N, 114°11’29.71”W

 Columbia 504 Northport, WA NASQAN (12400520) 11/3/97-11/4/97 48°58’21.70”N, 117°38’48.92”W Columbia 98 Grand Coulee, WA NCBP 11/6/97-11/7/97 47°57’44.85”N, 118°58’53.84”W Snake River (SR) 

Snake 41 Hagerman, ID Salmon 43 Riggins, ID Snake 42 Lewiston, ID 

Snake 96 Ice Harbor Dam, WA 

NCBP 10/2/97 42°47’36.21”N, 114°56’18.10”W

NCBP 9/30/97 45°35’43.42”N, 116°16’55.00”W

NCBP 9/24/97-9/25/97 46°24’54.28”N, 117°02’03.49”W 

NCBP 10/8/97-10/9/97 46°41’51.68”N, 118°53’07.88”W 

Middle Columbia River (MCR)

Columbia 503 Vernita Bridge, WA 

Columbia 97 Pasco, WA 

Yakima 44 Granger, WA 

NASQAN (12472900) 10/13/97-10/14/97 46°37’28.40”N, 119°51’31.45”W

NCBP 10/10/97-10/11/97 46°31’49.22”N, 119°16’42.07”W

NCBP 10/15/97-10/16/97 46°20’49.31”N, 120°12’27.03”W 

Lower Columbia River (LCR) 

Columbia 46 Cascade Locks, OR NCBP 

Columbia 502 Warrendale, OR NASQAN (14128910) 

Columbia 506 Vancouver, WA --

Willamette 45 Oregon City, OR NCBP 

Willamette 505 Portland, OR NASQAN (14211720) Columbia 501 Beaver Army Terminal, NASQAN (14246900)

OR 

11/18/97-11/20/97 45°41’23.11”N, 121°51’00.41”W

11/25/97-11/26/97 45°38’00.82”N, 121°58’42.57”W

4/2/98 45°35’44.21”N, 122°32’13.61”W 

11/21/97-11/24/97 45°19’03.47”N, 122°39’57.50”W

11/14/97-11/17-97 45°33’04.51”N, 122°41’43.74”W

3/31/98-4/1/98 46°10’57.86”N, 123°04’13.87”W 

Environmental Contaminants and their Effects on Fish 
13 

tamination of ground water, soil, and sludge with a variety of 

metals (Cr, Ni, Cu, and Pb), cyanide, fluoride, VOCs, PCBs, 

polycyclic aromatic hydrocarbons and trichloroethane (TCE). 

In addition to the industrial sites, two well fields for the city of 

Vancouver, Washington are contaminated with TCE. 

Materials and Methods 

Collection Sites 

Site selection for the 1997 BEST CRB study incorporated sites from previous investigations including NCBP and 

NASQAN. The overlap of sites allowed for comparison of 

fish tissue contaminant concentrations among studies. Fish 

were collected at sixteen sites in the CRB (Fig. 1; Table 3). 

Eight of the 16 sites were located on the Columbia River, two 

sites were on the Willamette River, three sites were on the 

Snake River, and one site was on each of the Yakima, Salmon, 

and Flathead Rivers. Seven sites were located in Washington, 

five sites were in Oregon, three sites were in Idaho, and one 

site was in Montana. Stations were grouped into four subbasins including the upper Columbia River (UCR), Snake 

River (SR), middle Columbia River (MCR), and lower Columbia River (LCR). These groups are not based on hydrology 

but rather geography to aid the reader in the physical location 

and distribution of sampling locations. The LCR had the most 

number of stations (Fig. 1). Ten sites corresponded to historical NCBP sampling stations, and five other sites represented 

NASQAN stations. Most fish were collected between early 

September and November 1997, but Stations 501 and 506 

were not sampled until April 1998 (Table 3). Sampling at 

each site was completed during one visit spanning 1-4 days. 

Target Species and Sampling Strategy 

This study was designed to retain comparability with 

historical NCBP data (Schmitt and others, 1999b) and other 

investigations based on composite samples of whole fish while 

also accommodating the biological measurements incorporated into the overall investigation (Schmitt and Dethloff, 

2000). Many of the biological instruments are gender-specific and require live or freshly killed individual fish. It was 

desirable to collect the same species at each site in a basin 

to standardize fish health and biomarker results. In previous NCBP collections (Schmitt and others, 1999b), the most 

prevalent bottom-dwelling species was carp, and the most 

prevalent predator species was the largemouth bass (Micropterus salmoide). These were also the targeted species in other 

BEST projects (Schmitt, 2002a; Schmitt and others, 2004). 

These species have a widespread distribution, abundant extant 

contaminant data, and thorough biological endpoint data. 

Materials and Methods 

Therefore, carp and largemouth bass were the preferred taxa at 

all CRB sites. Alternate species were permitted if these taxa 

could not be obtained. Preferred alternate species included 

sucker (Catostomidae) as alternate benthivores, and other 

black bass (Micropterus sp., henceforth bass) as piscivores. 

The collection target at each site was 10 (each) adult male and 

female of each taxon for a total of 40 fish per site. Collectors 

were instructed to obtain adult carp and bass of a size representative of those believed to be present based on extant information and to avoid extremely large or small fish. More than 

two species were collected at sites with incomplete quotas for 

the target or preferred alternate taxa could not be obtained. 

Monitoring Methods Overview 

A suite of chemical and biological methods was used 

to characterize the exposure of fish to contaminants and the 

effects of exposure (Schmitt and Dethloff, 2000). The suite 

included reproductive biomarkers, measures of cytochrome 

P450 enzyme induction, fish health assessments, and chemical 

analyses of fish carcasses (Table 4). Additional information 

on these methods is available elsewhere (see Schmitt, 2002a; 

Schmitt and Dethloff, 2000; Whyte and others, 2000; 2004). 

Concurrent determination of tissue residue concentrations 

along with the suite of fish health, immune system responses, 

and reproductive assessments supports the interpretation of 

relationships between exposure and biological responses. 

Table 5 identifies the organochlorine chemical and elemental contaminants measured in the fish carcass composite 

samples. These analytes were selected to provide the maximum amount of information on accumulative contaminants 

of interest at minimal cost and to maintain continuity with the 

historical NCBP database. Instrumental analyses of specific 

planar halogenated hydrocarbons (PHHs), such as PCB, 

polychlorinated dibenzo-p-dioxin (PCDD), and polychlorinated dibenzofuran (PCDF) congeners, were not included due 

to their high analysis cost. Instead, extracts of the composite samples were screened with the H4IIE rat hepatoma cell 

bioassay (Tillitt and others, 1991; Whyte and others, 2004), 

which responds to planar PHHs (Table 6). In addition, the 

livers of the individual fish were assayed for ethoxyresorufin 

O-deethylase (EROD) activity, which indicates recent exposure to exogenous AhR ligands including PHHs and planar 

aromatic hydrocarbons (PAHs) (Kennedy and Jones, 1994; 

Pohl and Fouts, 1980; Whyte and others, 2000). Together 

these assays and analyses allow for the estimation of the relative concentrations of potential biological effects of PHHs and 

PAHs without the expense of instrumental analyses for these 

compounds (Table 6). 

Measurement of fish health at various levels of biological 

organization, immune system responses, and reproductive status were included in the suite of indicators to address potential 

impacts from non-accumulative contaminants and contaminant mixtures (Table 4). Measures of fish health included: 
14 Environmental Contaminants and their Effects on Fish 

Table 4. Methods incorporated into the Columbia River Basin in 1997. 

Method Description Tissue(s) 

examined Sensitivity Primary 

reference(s) 

Histopathology Microscopic examination for 

the presence of lesions; can 

provide early indication of 

chemical exposure 

Liver, gill, 

gonads, spleen, 

and kidney 

Overall organism 

health and 

contaminants 

Hinton and others (1992); 

Hinton (1993); Goodbred 

and others (1997) 

Ethoxyresorufin Odeethylase (EROD) 

activity 

Enzyme induction by planar 

hydrocarbons 

Liver PCBs; 

chlorinated , 

dioxins, and 

furans; PAHs 

Pohl and Fouts (1980); 

Kennedy and Jones (1994); 

Whyte and others (2000) 

Macrophage 

aggregate analysis 

Macrophages are important in 

the immune system, serving as 

a first line of defense for the 

organism and as an antigen 

processing cell 

Spleen Multiple 

contaminants 

including PAHs 

and metals 

Blazer and others (1994; 

1997) 

H4IIE bioassay A screening tool to determine 

the presence of certain classes 

of planar halogenated 

compounds 

Whole fish 

(composite 

samples) 

PCBs; 

chlorinated 

dioxins and 

furans 

Tillitt and others (1991); 

Whyte and others (2004) 

Vitellogenin A precursor of egg yolk, 

normally synthesized in the 

liver of female fish 

Blood plasma Endocrinemodulating 

substances 

Denslow and others (1999) 

Chemical analyses Organochlorine chemical 

residues and elemental 

contaminants 

Whole fish 

(composite 

samples) 

Specific analytes Schmitt and others (1999a) 

Somatic indices The relative mass of some 

organs is often indicative of 

chemical exposure 

Gonads, spleen, 

liver 

Overall organism 

health 

Grady and others (1992) 

Necropsy-based fish 

health 

assessment 

Visual assessment of 

external/internal anomalies (for 

example, lesions, parasites, 

tumors), which may indicate 

contaminant-related stress 

All Overall organism 

health 

Goede (1988, 1996); 

Adams and others (1993); 

Adams (1990) 

1) gross observations for abnormalities; 2) condition and 

organosomatic indices; and 3) histopathological examination 

(Goodbred and others, 1997; Hinton, 1993; Hinton and others, 

1992). Gross observations and determination of indices based 

on relative fish and organ sizes such as condition factor (CF), 

hepatosomatic index (HSI), and splenosomatic index (SSI) 

are relatively simple and indicative of cumulative, organismlevel changes (Grady and others, 1992). However, they are 

non-specific in terms of causal mechanisms which may reflect 

early, subtle alterations and may foreshadow subsequent 

effects at the individual- or population-level. 

In addition to being an indicator of overall organism 

health, the SSI is also a measure of immune system stress. 

Other immune system indicators included the measurement 

of macrophage aggregates (MA) in preserved spleen tissue 

samples (Table 4). Macrophage aggregates, also known as 

melanomacrophage centers, are discrete aggregations of pigment-bearing macrophages found in the spleen, kidney, and 

sometimes liver of advanced teleosts (Agius, 1980). These 

specialized cells are thought to be responsible for centralizing foreign material and debris for destruction, detoxification or reuse, storing waste products, contributing to immune 

response, and storing/recycling iron (Ellis and others, 1976; 

Ferguson, 1976). Although they may be affected by a variety 

of factors, MA measurements have responded to contaminant 

exposure in both field and laboratory studies (Blazer and others, 1997; Wolke, 1992). 

Measures of reproductive condition included plasma 

vitellogenin (vtg) concentrations, gonadosomatic index (GSI), 

and gonadal histopathology (Table 4). Contaminants, particularly estrogen mimics, have been shown to impact reproduction in laboratory and field studies although reproductive condition in fish can be influenced by many factors (for example, 

gender, age, reproductive stage, season, water temperature) 
15 

Table 5. Organochlorine chemical and elemental contaminants measured in whole body fish composite samples.—Continued Contaminant class and analyte Chemical name(s) or atomic symbol Principal uses and sources to aquatic ecosystems Organochlorine chemicals 

p,p'-DDE p,p'-DDD (TDE) p,p'-DDT o,p'-DDE o,p'-DDD (TDE) o,p'-DDTTotal polychlorinated biphenyls (PCBs) DieldrinEndrinHeptachlor epoxide cis-Chlordanetrans-Chlordane 

cis-Nonachlor

trans-Nonachlor

Oxychlordane (octachlor epoxide) 

Toxaphene α-Hexachlorocyclohexane (HCH) 

2,2-bis (p-chlorophenyl)-1,1-dichloroethylene 

2,2-bis (p-chlorophenyl)-1,1-dichloroethane 

2,2-bis (p-chlorophenyl)-1,1,1-trichloroethane 

2-(o-chlorophenyl)-2-(p-chlorophenyl)-1,1-

dichloroethylene 

2-(o-chlorophenyl)-2-(p-chlorophenyl)-1,1-

dichloroethane 

2-(o-chlorophenyl)-2-(p-chlorophenyl)-1,1,1-

trichloroethane 

Mixture containing as many as 209 mono- through 

octa-chloro-substituted biphenyl congeners. 

1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4a,5,8,8ahexahydro-1,4-endnnno-exo-5,8-dimethanonaphthalene 

1,2,3,4,10,10-hexachloro-6,7-epoxy-1,4,4a,5,6,7,8,8aoctahdyro-1,4- endo-endo-5,8-dimethanonaphthalene 

1,4,5,6,7,8,8-heptachloro-2,3-epoxy-3a,4,7,7atetrahydro-4,7-methano-1H-indene 

 1,2,4,5,6,7,8,8-octachloro-2,3,3a,4,7,7a-hexahydro-4,7-

methano-1H-indene (1-α,2-α,3a-α,4-β,7-β,7a-α)

1,2,4,5,6,7,8,8-octachloro-2,3,3a,4,7,7a- hexahydro-4,7-

methano-1H-indene(1-α,2-β,3a-α,4-β, 7-β,7a-α)

1,2,3,4,5,6,7,8,8-nonachloro-2,3,3a,4,7,7a- hexahydro4,7-methano-1H-indene (1-α,2-α, 3-α, 3a-α, 4-β, 7-β, 

7a-α)

 1,2,3,4,5,6,7,8,8-nonachloro-2,3,3a,4,7,7a- hexahydro4,7-methano-1H-indene(1-α,2-β,3-α, 3a-α,4-β,7-β,7aα)

2,3,4,5,6,6a,7,7-octachloro-1a,1b,5,5a,6, 6a-hexahydro2,5-methano-2H-indeno(1,2-b)oxirene (1a-α,1b-β,2-

α,5-α,5a-β,6-β,6a-α)

Chlorinated camphene mixture averaging 62% chlorine 

by weight 1,2,3,4,5,6-hexachlorocyclohexane 

DDT-metabolite

Insecticide; DDT-metabolite 

Insecticide

o,p'-DDT metabolite 

o,p'-DDT metabolite p,p'-DDT impurity

Dielectric, hydraulic, and transformer fluids; lubricants; extenders; de-dusting agents; carbonless copy paper Insecticide; aldrin metabolite Insecticide; isodrin metabolite Heptachlor metabolite; technical chlordane constituent/metabolite Insecticide; technical chlordane constituent 

Technical chlordane constituent 

Technical chlordane constituent 

Technical chlordane constituent 

cis-Chlordane metabolite 

Insecticide; herbicide 

Constituent of insecticide mixture containing various 

HCH isomers; also know as α-benzene hexachloride 

(BHC) 

Materials and Methods 
16 Table 5. Organochlorine chemical and elemental contaminants measured in whole body fish composite samples.—Continued 

Contaminant class and analyte Chemical name(s) or atomic symbol Principal uses and sources to aquatic ecosystems 

β-HCHδ-HCHγ-HCH (Lindane) Hexachlorobenzene (HCB) Mirex

Elemental contaminants 

ArsenicCadmiumChromiumCopperLeadMercuryNickelSeleniumZinc 

1,2,3,4,5,6-hexachlorocyclohexane 1,2,3,4,5,6-hexachlorocyclohexane 1,2,3,4,5,6-hexachlorocyclohexane 

Perchlorobenzene 

1,1a,2,2,3,3a,4,5,5,5a,5b,6-dodecachloro- octahydro1,3,4-metheno-1H-cyclobuta(cd)pentalene 

As

Cd

CrCu

Pb

HgNi

Se

Zn 

Technical HCH (BHC) constituent 

Technical HCH (BHC) constituent 

Insecticide; technical HCH (BHC) constituent 

Fungicide; industrial intermediate 

Insecticide; fire retardant 

Industrial sources; herbicides; defoliants

Mining, smelting and other industrial sources; urban 

runoff; sewage discharges 

Mining, tanning, and other refractory and chemical industrial sourcesMining, smelting and other industrial sources 

Mining, smelting and other industrial sources; urban 

runoff; atmospheric pollution; fishing sinkers; lead shot 

Herbicides; fungicides; pulp, paper, and textile effluents;open-cycle chloralkali cells; landfills; mining; atmospheric pollution Mining, smelting, and other industrial sources 

Coal-fired powerplants; irrigation return flows 

Mining, smelting and other industrial sources; urban 

runoff

Environmental Contaminants and their Effects on Fish 
Materials and Methods 17 

Table 6. Monitoring and assessment strategy for 

polycyclic aromatic and polyhalogenated 

hydrocarbons (PAHs and PHHs). a Total PCBs 

were determined by gas chromatography with 

electron-capture detection. b 7-ethoxyresorufin Odeethylase. c H4IIE bioassay was performed after 

reactive cleanup to remove AhR-active PAHs. d 

And other planar organic compounds. + responds; 

– does not respond; *AhR-active isomers and 

congeners only. 

Contaminants 

Endpoint PCDDs & PCBs PAHs d 

PCDFs 

GC-ECD a + - -

(carcass) 

EROD activity b * * * 

(liver) 

H4IIE bioassay c * * -

(carcass) 

(Allen and others, 1999; Gimeno and others, 1998). Estrogen 

mimics are capable of stimulating the production of vtg, a 

precursor of yolk protein, in the livers of oviparous vertebrates, and a number of endocrine disrupting compounds have 

been shown to induce abnormal vitellogenesis (Servos, 1999; 

Tyler and others, 1998). Vitellogenin production is normally 

associated with female fish; however, it can be produced in 

males if estrogen or an estrogen-like chemical is present. The 

detection of levels typical of early- to mid-vitellogenic females 

in male fish has been associated with exposure to exogenous 

estrogens (Bowman and others, 2002; Denslow and others, 

1999; Folmar and others, 1996; 2000; 2001). Vitellogenin was 

measured in both male and female fish to document these and 

other possible alterations and to establish baseline concentrations. The GSI and gonadal histopathology [stage, presence 

of atretic oocytes, and intersex conditions (presence of female 

reproductive tissue in males or vice-versa)] were also assessed 

as measures of reproductive health and status. The GSI relates 

the proportional size of the gonad to the body size and may 

reflect changes resulting from a variety of physiological factors such as reproductive stage and environmental factors, 

including exposure to contaminants. Elevated occurrence of 

atretic (unfertilized and/or reabsorbed) eggs has been noted in 

fish exposed to contaminants (Cross and Hose, 1988; Johnson 

and others, 1988), although other factors may also be involved. 

Feminization of male fish (that is, intersex condition) has been 

reported in laboratory and field studies of contaminants (Allen 

and others, 1999; Gimeno and others, 1997; 1998; Jobling and 

others, 1998). 

Field Procedures 

Fish Collection 

Fish were collected by electrofishing from a boat along 

the shoreline or backwater areas of the river being sampled. 

All specimens of the target species were collected, irrespective of size, although electrofishing tends to be biased toward 

larger fish (Reynolds, 1983). More than 10 fish of a given 

species and gender were processed at some sites. Global 

Positioning System (GPS) coordinates were obtained for the 

upstream and downstream extents of the area from which fish 

were collected. Fish were held in on-board live wells and 

transported to shore for processing, usually within a few hours 

of collection. Fish at certain stations were held alive overnight 

in tanks or net pens containing ambient river water following 

night collections. 

Sample Processing 

The methods used to process the fish have been fully 

described (Table 4) (Schmitt and Dethloff, 2000). Briefly, 

a live fish was selected and identified to species. A blood 

sample was collected from the posterior caudal artery and 

vein with a heparinized needle and syringe and placed on 

[wet] ice. Plasma from this blood sample was later obtained 

for determination of the vtg concentration. The fish was 

weighed, measured, and subdued. Observations of external 

features were recorded, and tissue anomalies were removed 

by dissection and preserved in 10% neutral buffered formalin 

for histopathological analysis. The abdominal cavity of the 

fish was dissected open and the liver (in species with a discrete 

liver), spleen, and gonads were removed and weighed. Liver 

weights for carp and sucker were not determined because 

these species have a dispersed hepatic organ. The liver, gall 

bladder, posterior and anterior kidneys, gonads, mesenteric fat 

(in certain species), and spleen were examined, and the gender 

of the fish was determined. Pieces of liver collected for EROD 

activity analysis were immediately flash-frozen in a dry iceethanol slush, then transferred to a liquid nitrogen dry-shipper 

for storage and shipment. Samples of gonad, kidney, spleen, 

and additional pieces of liver were collected and preserved in 

10% neutral buffered formalin for histopathological examination, gender confirmation (gonad), and macrophage aggregate 

analysis (spleen). Scales were collected for age determination 

upon completion of the internal examination and dissection. 

Remaining tissues (those not frozen or fixed) were placed 

back into the body cavity and the entire fish was wrapped in 

aluminum foil. The wrapped carcass was labeled and placed 

in a polyethylene bag with other carcasses of the same species 

and gender. These samples were chilled and later frozen for 

analysis of organochlorine chemical and elemental contaminants and dioxin-like activity (with the H4IIE bioassay). The 
18 Environmental Contaminants and their Effects on Fish 

entire field procedure was typically conducted in 15-20 min 

(per fish), and tissue samples, especially liver for EROD 

analysis, were collected and frozen as rapidly as possible. 

Blood samples were centrifuged and the plasma was aspirated 

and frozen in dry ice following the processing of the fish. 

Laboratory Analyses 

Composite fish samples were shipped frozen in dry ice 

to laboratories managed by the Patuxent Analytical Control 

Facility (PACF) of the USFWS where they were prepared and 

analyzed for organic and elemental contaminants. These laboratories also prepared the composite samples for H4IIE bioassay analyses, which were conducted by the USGS (United 

States Geological Survey) CERC (Columbia Environmental 

Research Center). PACF oversaw quality assurance (QA) and 

quality control (QC) associated with these procedures. Recovery of spiked materials in the samples were evaluated to assess 

the quality of the procedures but were not used to adjust the 

concentration of the reported analytes. Additional information 

on sample preparation and chemical methods are presented 

by Schmitt and others (2002b). Cryogenically frozen liver 

samples for EROD analysis were also shipped to CERC for 

analysis. Cryogenically frozen plasma samples were similarly 

shipped to the Protein Chemistry Research Laboratory of the 

University of Florida for analysis of vtg. All preserved tissue 

samples were shipped to the National Fish Health Laboratory 

of the USGS Leetown Science Center (LSC) for histopathological analysis. Information on these latter procedures are 

given by Blazer and others (2002) and McDonald and others (2002). Scales were processed for age determination as 

described by Jearld (1983), with age (years) estimated from 

the number of completed annuli. 

Composite Sample Preparation 

Carcass samples were stored frozen (-20oC) at the lead 

analytical laboratory (Lab 1) until they were processed. 

Carcasses were composited by gender and species from each 

sampling station (for example, Station 42 female carp), and 

total number of individual fish in the composite sample varied. 

The carcass of each individual fish was sawed into pieces for 

processing, and the pieces were then mixed and homogenized 

in a commercial meat grinder. One sub-sample (100 g) of the 

composite was re-frozen (-20o

C) and shipped frozen to Lab 2 

for analysis of moisture content and elemental contaminants. 

A 10-g subsample was extracted with methylene chloride, 

subjected to the reactive cleanup procedure described in following sections, ampulated, and shipped to CERC for use in 

the H4IIE bioassay. Another 10-g subsample was retained by 

Lab 1 for analysis of organochlorine chemicals by gas chromatography with electron capture detection (GC-ECD) and 

gravimetric determination of lipid content. 

Elemental Analysis and Moisture Content 

The 100-g sub-samples were freeze-dried and moisture 

loss was determined by weight loss during lyophilization at 

Lab 2. Freeze-dried fish (25-50 g) were digested in nitric acid. 

Concentrations of total As, Pb, and selenium (Se) in the digestates were determined by graphite furnace atomic absorption 

spectroscopy (AA). Concentrations of Hg were determined 

by cold vapor AA. Concentrations of aluminum (Al), barium 

(Ba), beryllium (Be), boron (B), Cd, Cr, cobalt (Co), Cu, Fe, 

magnesium (Mg), Mn, molybdenum (Mo), Ni, Ag, strontium 

(Sr), thallium (Th), vanadium (Va), and Zn were determined 

by inductively coupled plasma emission spectroscopy (ICPES) 

without pre-concentration. Quality assurance measures for 

elemental analyses included the analysis of reagent blanks, 

duplicate samples, certified reference materials, and fortified 

samples (Table 7). Results for the other measures were typical 

for the elements reported here and indicate that the analytical 

results accurately reflect true concentrations in the samples. 

Dry-weight (dw) limits of detection (LOD) were determined 

individually for each analyte in each sample, but were nominally 5 μg/g for Al; 15 μg/g for Fe and Mg; 0.19 μg/g for Be, 

Cd, and Hg; 0.3 μg/g for Sr; 0.4 μg/g for Pb; 0.9 μg/g for As, 

Ba, Cr, Cu, Mo, Ni, Se, and V; 2 μg/g for B; 1.5 μg/g for Zn; 

and 0.5 μg/g for Mn (Table 7). These values, as well as the 

analytical results, were converted to wet-weight (ww) concentrations for statistical analysis and reporting. Additional information on the analyses of samples for elemental contaminants 

has been reported elsewhere (Schmitt and others, 2002b). 

Organochlorine Chemical Analysis and Lipid 

Content 

At Lab 1, one 10-g subsample of each ground composite 

sample was mixed with anhydrous sodium sulfate and Soxhletextracted with hexane, concentrated by rotary evaporation, and 

dried to constant weight for gravimetric lipid determination. 

Tissue extracts were re-dissolved in petroleum ether and fractionated on Florisil® in two fractions. A fraction containing 

relatively polar organochlorine insecticides, was concentrated 

for quantification of residues by dual megabore-column GCECD. Another fraction further processed by column chromatography on silicic acid to separate HCB (hexachlorobenzene), 

mirex, PCBs, and hydrophobic organochlorine pesticides. 

Each of the resultant fractions were concentrated and analyzed by megabore-column GC-ECD. Precision and accuracy 

of these determinations were ascertained through included 

analyses of duplicates and fortified samples (n=5), and residue 

identities were confirmed in selected samples. Recovery efficiency ranged from 88.6% for α-BHC to 99.2% for mirex, but 

averaged 80-95% for most analytes (Table 8). Based on these 

results, the analyses were determined to accurately represent 

the true residue concentrations in the samples. The nominal 

LOD for individual compounds was 0.01 μg/g ww and the 
Materials and Methods 19 

Table 7. Nominal limits of detection (LOD) and results of quality assurance (QA) for elemental contaminants a (μg dry-weight) analyzed in whole body fish composites from the Columbia River Basin. Sample size 

equals 5 for all contaminants except for Hg where n=6. b Maximum concentration of elemental contaminants 

in reagent blanks on a wet-weight basis assuming 75% moisture. c Reference material was NRCC TORT-2 

(Lobster hepatopancreas). 

Element 

n 

As Cd Cr Cu Hg Ni Pb Se Zn 

Reagent blanks a (μg dw) 5

Min. 0.00 0.00 

Max. 0.06 0.02 

Mean 0.02 0.01 

0.00 0.02 0.00 0.00 0.00 0.01 0.00 

0.06 0.10 0.00 0.07 0.05 0.07 0.12 

0.03 0.06 0.00 0.04 0.02 0.04 0.07 

b Max. (μg/g ww) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Duplicate sample analyses 5 

 (% difference) 

Min. 1.57 0.26 2.64 1.80 1.93 1.44 1.57 1.34 2.75 

Max. 32.9 16.7 57.5 26.4 26.0 71.8 6.04 21.6 9.22 

Mean 9.01 6.31 22.9 9.48 10.2 18.8 3.86 7.87 6.47 

Reference materials c 5

 (% recovery) 

Min. 86.6 101 96.8 87.9 93.2 93.0 86.7 99.1 88.6 

Max. 106 109 128 93.9 103 97.6 112 107 98.6 

Mean 92.9 105 120 92.1 99.3 95.5 105 103 95.3 

Cert. conc. (μg/g dw) 21.6 26.7 0.77 106 0.27 2.50 0.35 5.6 180 

Fortified spiked sample 5 

 (% recovery) 

Min. 88.2 97.6 96.2 94.1 88.4 99.2 100 94.9 81.3 

Max. 108 110 109 103 96.9 109 106 110 114 

Mean 99.7 104 104 100 93.3 104 103 101 102 

Nominal LOD (μg/g dw) 1.0 0.2 0.5 0.5 0.2 1.0 0.4 1.0 2.0 

LOD was 0.03 μg/g ww multi-component chemicals (toxaphene and PCBs) (Table 8). Chemical concentrations were 

not adjusted for recovery efficiency. Additional information 

on the organic analyses has been reported elsewhere (Schmitt, 

2002b). 

H4IIE Rat Hepatoma Cell Bioassay 

The 10-g sub-samples for H4IIE analysis were kept 

frozen at Lab 1 until the initiation of sample processing. Full 

details of processing have been previously described (Schmitt 

and others, 2002b). Briefly, samples were thawed, homogenized, and column extracted with methylene chloride. Percent 

lipid was determined gravimetrically on a 1% portion of the 

extract. The remainder was concentrated and cleaned up by 

two-stage column chromatography. Extracts were evaporated, 

re-dissolved with isooctane, ampulated, and shipped to CERC 

for analysis. Matrix QC samples (blanks and spikes) prepared 

at Lab 1 and at CERC included ground tissues from laboratory-raised bluegill (Lepomis macrochirus) and samples of 

a CERC standard positive control tissue (carp from Saginaw 

Bay, Michigan). These QC samples were processed concurrently with the 1997 samples. 

The H4IIE bioassay was performed on the composite 

sample extracts according to the method of Tillitt and others 

(1991) as modified for 96-well microtiter plates (Tysklind and 

others, 1994). The H4IIE cells were seeded at 7000 cells/ 

well in 300 μL of D-MEM culture media (Tillitt and others, 

1991) and were dosed with sample extracts or standards in 

isooctane after a 24 hour (h) incubation (Schmitt and others, 

2002b; Whyte and others, 2004). 2,3,7,8-tetrachlorodibenzop-dioxin (TCDD) was the standard and at least three TCDD 

standard curves were analyzed each day. A linear regression 

was performed on the data from each well to determine an 

EROD rate (pmol/min). The amount of protein in each well 

was determined by the fluorescamine assay (Lorenzen and 

Kennedy, 1993) and used to normalize the dose to each well 

and EROD activity. The doses of each sample (g-equivalents/ 

mg cellular protein) or TCDD standard (pg TCDD/mg cellular 
20 Environmental Contaminants and their Effects on Fish 

Table 8. Nominal limits of detection (LOD) and results of quality assurance (QA) for 

organochlorine chemicals (μg wet-weight) analyzed in whole body fish composites collected from 

the Columbia River Basin. Minimum, maximum, and mean fortified spike recovery percentages 

and duplicate sample difference percentages are presented unless otherwise indicated (ND, not a determined). Toxaphene- and PCB-fortified samples were not analyzed because 

multicomponent analytes interfered with the spike analyses. b All toxaphene and total PCB 

samples had an LOD of 0.03 μg/g except sample 506B which had a LOD of 0.05 μg/g. 

Fortified spike recoveries Duplicate sample LOD differences 

(μg/g) Analyte Min. Max. Mean Min. Max. Mean 

Lipid 

Moisture 

o,p’-DDD 

o,p’-DDE 

o,p’-DDT 

p,p’-DDD 

p,p’-DDE 

p,p’-DDT 

cis-Chlordane

trans Chlordane 

cis-Nonachlor 

trans-Nonachlor

Oxychlordane 

Heptachlor epoxide 

Dieldrin 

Endrin 

HCB 

Mirex 

-BHC 

-BHC 

-BHC 

-BHC 

Toxaphene a

Total PCBs a

ND 

ND 

93.5 

90.0 

85.0 

83.5 

84.5 

87.5 

88.5 

87.5 

88.0 

90.0 

85.0 

86.5 

90.5 

94.0 

73.5 

95.0 

78.0 

86.5 

84.0 

81.0 

ND 

ND 

ND 

ND 

105 

99.0 

97.0 

99.0 

97.0 

102 

104 

100 

102 

98.5 

100 

98.0 

100 

104 

93.5 

102 

94.0 

98.0 

97.5 

95.0 

ND 

ND 

ND 

ND 

99.0 

95.1 

91.3 

91.0 

91.4 

91.9 

96.5 

94.7 

95.0 

94.5 

93.5 

93.8 

96.1 

99.0 

84.1 

99.2 

88.6 

94.0 

90.9 

90.3 

ND 

ND 

1.9 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

10.8 

3.3 

0 

0 

0 

12.5 

9.2 

0 

0 

0 

0 

9.5 

0 

0 

16.7 

0 

0 

0 

0 

0 

0 

0 

0 

20.3 

4.7 

1.5 

0 

0 

0 

2.5 

5.8 

0 

0 

0 

0 

2.6 

0 

0 

3.3 

0 

0 

0 

0 

0 

0 

0 

0 

6.5 

ND 

ND 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.01 

0.03/0.05 b 

0.03/0.05 b 

protein) were plotted against EROD activity (pmol/min/mg blocks of approximately 40. LOD and limit of quantitation 

cellular protein, hereafter pmol/min/mg) to develop dose- (LOQ) were computed separately for each block. LODs 

response curves. The linear portions of these curves were used ranged from 0-1 pg/g and LOQs were 1 pg/g (rounded to 

to compare the relative potencies of the samples to the TCDD the nearest whole number). The results of the QA program 

standard. TCDD-equivalents (TCDD-EQ) were determined by indicated that the bioassays accurately reflected the dioxin-like 

a slope-ratio assay (Finney, 1980) as described by Ankley and potency of the extracts (Birke and Tillitt, 2000a). 

others (1991). Variance estimates were based on an additive 

model of variance (Finney, 1980) and were calculated as previously described (Ankley and others, 1991; Tillitt and others, 

1991). 

Quality assurance procedures and results are documented 

by Birke and Tillitt (2000a). Samplese were analyzed in 
21 

EROD Activity 

Cryogenically frozen liver samples were stored at –80°C 

by CERC until the preparation of microsomal fractions which 

were used the day they were prepared. The kinetic microsomal assays were conducted in 96-well microtiter plates 

(Birke and Tillitt, 2000b; Whyte and others, 2000). Briefly, 

triplicate determinations of EROD activity were performed 

on 5-μL portions of each microsomal preparation, and mean 

EROD activity was reported. Protein content was determined 

using the fluorescamine protein assay (Lorenzen and Kennedy, 1993) in the same 96-well microtiter plate as the EROD 

analyses. A positive control material [liver microsomes 

from laboratory-raised channel catfish (Ictalurus punctatus) 

injected with 10 mg/kg of benzo(a)pyrene] and an additional 

reference material [liver microsomes of wild flathead catfish 

(Pylodictis olivaris) obtained from the Missouri River near 

Easley, Missouri] were also analyzed. A linear regression was 

performed on the data from each well to determine an EROD 

rate (pmol/min) along with its associated estimate of variance. The amount of protein was used to normalize EROD 

activity (pmol/min/mg) in each well. A rigorous QA program 

was followed for the EROD assays as described in Birke and 

Tillitt (2000b). LODs ranged from 0–0.15 pmol/min/mg 

while LOQs ranged from 0-0.35 pmol/min/mg. The results 

of this QA program indicated that the results of the bioassay 

accurately reflected the hepatic EROD rates of the samples 

analyzed. 

Fish Health Indicators 

General Histopathological Analyses 

Tissues (liver, kidney, spleen, gill, gonad, and grossly 

visible lesions) preserved in 10% neutral buffered formalin 

(NBF) were shipped to the LSC and prepared for routine 

histopathological analysis (Blazer and others, 2002). Paraffinembedded tissue sections (6-μm) mounted on glass slides were 

stained with hematoxylin and eosin (H & E) for microscopic 

examination. 

Quantitative Organism-Level Indicators 

The prevalence of gross external pathological disorders 

was determined with a rating of present (1) or not present 

(0) deduced from the field data. The gross pathologies were 

selected for consistency with other monitoring programs that 

have used this type of assessment (Fournie and others, 1996). 

Gross abnormalities included grossly visible disorders of the 

eye (exophthalmia, hemorrhage, opacity, emboli, missing), 

opercles, (shortening, deformities, parasites), and body surface 

(ulcers, parasites, discolored areas or tumors). In addition, 

Materials and Methods 

disorders of the fins (hemorrhage, fraying, and so forth) and 

skeleton (curvature) were also included. Numerical values 

were assigned to internal and external observations of lesions 

recorded in the field, and a necropsy-based fish health assessment (HAI) score was calculated for each fish by summing 

these values for all organs (Blazer and others, 2002). An 

index was only computed for a fish if there was a complete 

assessment. 

Body and organ weights measured in the field were used 

to calculate condition and organosomatic indices. Condition 

factor was computed as body weight/length3

. The hepatosomatic index was calculated as HSI = liver weight/(total body 

weight – gonad weight) X 100. Similarly, the splenosomatic 

index was calculated as SSI = spleen weight/(total body 

weight – gonad weight) X 100. The weight of the gonads 

was subtracted from the body weight in the computation of 

HSI and SSI to minimize the effect of the reproductive cycle 

on these indices (Schmitt and Dethloff, 2000). Gonadosomatic index was calculated as GSI = gonad weight/total body 

weight X 100. Additional information on these indices is 

given by Schmitt and Dethloff (2000) and Blazer and others 

(2002). 

Macrophage Aggregates 

Macrophage aggregates (MA) and MA pigments in 

spleen sections were visualized through a staining procedure 

called the Perl’s method (Luna, 1992). Using this method, 

melanin, a melanosome pigment derived from tyrosine 

metabolism, stains black; hemosiderin, a protein-bound iron 

pigment, stains blue; and ceroid/lipofuscin, lipogenic pigments 

arising from the oxidation of unsaturated lipids, stains yellowtan. All MA measurements were made with a computer-based 

image analysis system, and included the number of aggregates 

in 2 mm2 of tissue (MAMM) and the area occupied by aggregates. The percentage of tissue occupied by MAs (TISSOC) 

and mean area of the MAs (MEANAREA) were computed 

from these measurements (Blazer and others, 2002). 

Reproductive Indicators 

Gonadal Histopathology 

The posterior tip of the gonad was dissected in the field 

and fixed immediately in 10% NBF. Transverse sections were 

processed for routine light microscopy (embedded in paraffin, 

sectioned at 6 μm, and stained with H & E). 

Female gonadal tissue was staged using developmental 

stages (designated 0-5) to classify each section (Blazer, 2002; 

Nagahama, 1983; McDonald and others, 2000; Rodriguez 

and others, 1995; Treasurer and Holliday, 1981). Carp and 

bass ovaries typically contain oocytes in several develop­
22 Environmental Contaminants and their Effects on Fish 

mental stages and were classified according to the maturity 

of the predominant stage of oogenesis of each tissue sample. 

Ovaries containing only previtellogenic chromatin nucleoli 

and perinuclear oocytes, which were identified by cytoplasm 

that stained basophilic with H & E, were assigned to stage 0. 

Samples containing many oocytes with cortical alveoli in addition to the previtellogenic chromatin nucleoli and perinuclear 

oocytes characteristic of stage 0 were assigned to stage 1. 

Ovaries containing primarily oocytes with cortical alveoli and 

yolk globules filing the cytoplasm were classified as stage 2 

(early vitellogenic). Those containing larger oocytes in which 

the cortical alveoli were pushed to the periphery of the cell, 

yolk globules filled the center, and the chorion of the developing oocytes were thicker than in earlier stages were designated 

as stage 3 (mid-vitellogenic). Ovaries containing oocytes 

with fused yolk globules that appear as a homogeneous mass 

were designated as stage 4 (mature). Ovaries containing 

post-ovulatory follicles, which can be observed for some time 

after ovulation, are typically assigned to stage 5 (spent). After 

the ovarian tissues were staged they were further examined 

by light microscopy for atresia and other pathologies. One 

hundred oocytes in each sample were counted when possible 

to determine atresia. Those showing morphological evidence 

of resorption or necrosis were quantified and the percent of 

atretic oocytes were calculated. 

Analogous to the procedure used to stage ovaries, male 

gonadal tissue was classified into five developmental stages 

(0-4) according to the maturity of the predominant stage of 

spermatogenesis of each tissue sample (Blazer, 2002; Nagahama, 1983). Immature, undeveloped, or regressed testes 

containing only spermatogonia were classified as stage 0 

(immature) whereas those containing primarily spermatocytes 

and spermatids were designated as stage 1 (early spermatogenic). Stage-2 (mid-spermatogenic) testes contain approximately equal proportions of spermatocytes, spermatids, and 

spermatozoa, and testes containing primarily mature spermatozoa were identified as stage 3 (late spermatogenic). Stage-4 

gonadal tissue is post-spawning or spent. Testicular tissue was 

also examined microscopically for any abnormalities such as 

intersex and other pathologies. Male fish were classified as 

intersex when individual or small foci of undeveloped oocytes 

were observed within testicular tissue (that is, when an ovotestis condition was detected). 

Vitellogenin 

A sandwich ELISA was used to determine concentrations of vtg in plasma samples obtained from bass, carp, and 

largescale sucker (Denslow and others, 1999). Monoclonal 

antibodies (mAb) developed specifically against bass (3G2) 

or carp (2D4) vtg were utilized. Wells of a microtiter plate 

were saturated with 10 μg/mL of species-specific mAb in 

phosphate-buffered saline (50 μL/well). Plates were incubated overnight, then washed with Tris-buffered saline-Tween 

(TBST). Blocking reagent (10% BSA in TBST, 360 μL/well) 

was added to each well and allowed to incubate for 2 h. Plates 

were washed with TBST and 50 μL of standard or samples 

were added and incubated overnight. Unknown plasma 

samples were diluted from 1:10,000 (bass) to 1:1000,000 

(carp) in 1% BSA-TBST containing 10 kIU/mL of Aprotinin 

as protease inhibitor. Standard curves were prepared by diluting purified vtg in diluted plasma from control male fish of the 

same species tested. After overnight incubation, plates were 

washed with TBST and 50 μL of 1:1000 rabbit polyclonal 

antiserum in 1% BSA-TBST was added to each well. After a 

2 h incubation, plates were washed and 50 μL of goat anti-rabbit F(ab)2 alkaline phosphatase conjugate in 1% BSA-TBST 

was added to each well as the secondary antibody. The plates 

were incubated for another 2 h, then washed and 100 μL of 

p-nitrophenyl phosphate in carbonate buffer was added to each 

well and incubated for 30 min. The reaction was stopped by 

addition of 50 μL/well of 3N NaOH. Plates were read at 405 

nm in an automated microtiter plate reader (Spectromax Pro, 

Applied Biosystems). Concentrations of the unknowns were 

determined from the standard curves. 

Concentrations of plasma vtg were determined by 

direct ELISA using the monoclonal antibody, 2C11 (HL 1689) 

for the largescale sucker ELISA. The plasma samples were 

diluted 1:200, 1:10,000, 1:100,000, and 1:1,000,000 with 

10mM phosphate, 150mM NaCl, 0.02% azide, 10 KIU/mL 

Aprotinin, pH 7.6 (PBSZ-AP). Vitellogenin standards (0, 

0.005, 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0 

μg/mL) containing 1:200, 10k, 100k, and 1000k male white 

sucker (Catostomus commersoni) plasma (in PBSZ-AP) 

were added to account for matrix effect (Denslow and others, 

1999). Samples and standards were loaded onto a 96-well 

ELISA plate (NUNC) in triplicate and stored overnight at 4oC 

in a humidified container. The following day the plates were 

washed four times with PBSZ and then blocked with 1% BSA 

in 10mM tris, 150mM NaCl, 0.05% tween, 0.02% azide, 10 

KIU/mL Aprotinin, pH 7.6 (1% BSA/TBSTZ-AP) for 2 h at 

room temperature. The plates were rewashed with PBSZ (4 

times) and the monoclonal, loaded to each plate. The lowest 

dilution (1:200) was probed with 3 μg/mL of the mAb and 

dilutions of 10k and higher with 1.0 μg/mL. After the addition of the mAb, the plates were stored at 4oC overnight in 

the humidified container. The following day the plates were 

washed and the biotinylated secondary antibody (goat anti 

mouse IgG-biotin) was added to each well at 1:1000 dilution 

in 1% BSA/TBSTZ-AP and incubated at room temperature 

for 2 h. The plates were washed, and strepavidin-alkaline 

phosphatase was added at 1:1000 dilution in 1% BSA/TBSTZAP and incubated for 2 h at room temperature. After washing 

the plates for the final time, the color was developed by adding 

1 mg/mL p-nitro-phenyl phosphate in carbonate buffer (0.03M 

carbonate, 2mM MgCl2

, pH 9.6) and measuring the color 

using an ELISA plate reader (SpectraMax Plus384, Applied 

Biosystems) at 405 nm. Concentrations of the unknowns were 

determined from the standard curves. 

The LOD was 0.0005 mg/mL of plasma for sucker 

vtg direct ELISA, 0.002 mg/mL for bass vtg sandwich ELISA, 
23 

and 0.005 mg/mL for carp vtg sandwich ELISA. All assays 

were performed in triplicate and reported as the mean of the 

three measurements. The coefficient of variation was <10% 

for all samples analyzed. Inter-assay variability was routinely 

measured by analyzing controls on several plates and was 

found to be <10%. 

Data Set Composition and Statistical Analyses 

Species were grouped into larger taxon groupings for 

analysis. These included common carp, largescale sucker, 

bass (largemouth and smallmouth bass), longnose sucker 

(Catostomus catostomus), northern pikeminnow, rainbow trout 

and walleye. For indicators based on individual fish (that is, 

biomarkers and demographic endpoints), data are discussed in 

terms of the magnitudes of the means or medians for combined stages or each stage within a gender for different species 

or taxon grouping. Data were summarized graphically with 

boxplots presenting the range, median, mean, and 25th and 75th 

percentiles. Whiskers are 10th and 90th percentiles overlain 

by a scatter plot of individual fish data (Sigma Plot 7.0 2001, 

Microsoft, Inc.). Some biomarkers including EROD, vtg, and 

HAI were also analyzed more rigorously (see following sections). Transformations for statistical testing were applied as 

necessary to achieve the normality and homogeneity of variance required for the application of parametric statistical methods. The transformations were the same as those used in the 

analysis of the more extensive 1995 MRB data set including 

log transformation of EROD and vtg and rank transformation 

of HAI because the 1997 data set is relatively small (Schmitt, 

2002a). Concentrations of contaminants and TCDD-EQ in 

composite samples were also log-transformed. Transformations were not applied to the other variables analyzed. Raw 

data from this study can be obtained at <http://www.cerc.usgs. 

gov/data/best/search/>. 

Descriptive statistics (arithmetic mean, minimum, 

maximum, and standard error) were computed for length, 

weight, and age data for species and taxon groupings at each 

station. Fish for which only regenerated scales were collected 

(42 fish; 25 carp, 1 largemouth bass, 7 largescale sucker, 9 

northern pikeminnow) were reported as ND (not determined) 

and excluded from interpretation of age data and all analyses 

that included age as a factor. Fish for which the field gender 

identification could not be verified histologically (including 

four individuals from targeted species) were reported as NG 

(no gonad) and likewise excluded from analyses that included 

gender as a factor. Data for bass, carp, and largescale sucker 

are presented in tabular form and discussed. Because of the 

influence of fish size on concentrations of Hg in predatory 

fish, length and weights were also analyzed statistically (see 

next section). Length and weight data for all other species are 

presented only in tabular form. 

Composite samples (n=64) from 16 stations were 

analyzed for organochlorine chemical residues, elemental conMaterials and Methods 

taminants, and TCDD-EQ by the H4IIE bioassay. Seventeen 

samples (26.5%) from nine stations were carp, 17 samples 

(26.5%) from nine stations were largescale sucker, and 21 

(33%) samples from 11 stations were bass. The remaining 

nine samples (14%) were comprised of northern pikeminnow 

(six samples at five stations), rainbow trout (two samples at 

one station), and walleye (one sample at one station). All 

results for composite samples were converted to, analyzed 

statistically as, and reported as ww concentrations. A value of 

one-half the LOD was substituted for censored values in the 

computation of un-weighted geometric station means and for 

statistical analyses (Schmitt and others, 1999b). A value of 

one-half the LOD was also substituted for censored values in 

all graphs. 

Concentrations of many contaminants in 1997 composite samples were <LOD, which limited the extent and rigor 

of statistical analyses that could be performed. All data for 

composite samples (tissue concentrations and H4IIE results) 

are presented graphically and as tabular summaries. For p,p’-

DDE, PCBs, As, Cd, Cu, Hg, Pb, Se, and Zn, temporal and 

geographic differences were also examined statistically using 

ANOVA. Log-transformed concentrations of these analytes in 

carp, bass, largescale sucker, and northern pikeminnow were 

combined with historical NCBP data for these taxa (Schmitt 

and others, 1999b) at the 10 sites in the CRB (Stations 41, 42, 

43, 44, 45, 46, 96, 97, 98, and 117). These data were analyzed 

as a one-way ANOVA in which samples representing stations, 

collection years, and taxa were separated into 325 unique 

combinations (“treatments”). Selected pair-wise comparisons 

of least-squares treatment means representing 1997 concentrations contrasted against previous years within each station-taxon combination were then conducted using Fischer’s 

protected LSD. Treatments representing the 1997 stationtaxon means were also compared as part of this analysis. 

These single degree-of-freedom, non-orthogonal contrasts are 

essentially a series of t-tests using a pooled error mean-square 

(MSe

) that evaluate differences between- or among-samples of 

the same taxon. A nominal α-level of 0.01 was used in these 

comparisons to protect against experiment-wide error. Concentrations of Hg in predatory fish were log-transformed and 

length-adjusted (HgL) and weight-adjusted (HgW) concentrations due to the influence of size and age (Wiener and others, 

2002). The adjusted Hg values were computed by dividing 

the measured concentration in each composite sample by the 

mean length (m) and weight (kg) of the individual fish comprised by the sample (Brumbaugh and others, 2001). Mean 

age of the composite samples from some stations could not be 

estimated due to the large number of fish having re-generated 

scales; therefore, age-adjustment of the concentrations of Hg 

could not be performed. In addition, the NCBP fish collected 

historically were not aged. 

Many biomarkers differ among species, gender, and 

reproductive stages (Schmitt, 2002b; Schmitt and Dethloff, 

2000). Accordingly, a series of linear ANOVA models were fit 

to the individual fish data for bass, carp, and largescale sucker 

to determine the influence of selected factors on biomarker 
24 Environmental Contaminants and their Effects on Fish 

responses in these taxa. Station and gender were treated as 

class variables while age and stage were considered continuous variables in these models, and the models included both 

main effects and interactions. The results of these analyses 

were reported as F-values and significance levels and were 

used to guide the graphical presentation and discussion of the 

findings. Most means were not adjusted for the factors in the 

models because of the complexity of the models relative to the 

small size of the data set. The exception was the MA variables 

because of the known increase in MA density (MAMM) over 

time (Blazer and others, 2002). The MA data were re-analyzed with a model that included age as a class variable, and 

age-adjusted station means for MA parameters in bass, carp, 

and largescale sucker were estimated. There was no evidence 

that age was associated with MA data in carp and largescale 

sucker. Results are generally presented and discussed in terms 

of the magnitudes of the means or medians for combined genders or each gender within a species or taxon grouping and at 

different stations within a species or taxon grouping. 

Correlations between biomarker results and concentrations of selected contaminants in carp, bass, and largescale 

sucker were also examined. For these analyses, mean biomarker responses in the individual fish comprised by each 

composite sample were compared to contaminant data. Spearman rank correlations were computed for samples representing 

male and female bass, carp and largescale sucker (combined 

within taxon). 

Results and Discussion 

Geographic Distribution and Demographic 

Characteristics of the Fish Collected 

A total of 560 fish representing eight species from 16 

stations were collected in the CRB (Table 9). Bass, carp, and 

largescale sucker accounted for 80% of the fish collected. 

Only northern pikeminnow accounted >10% of the total fish 

count of the four remaining species. Largescale sucker were 

collected at ten stations, carp and smallmouth bass at nine, 

largemouth bass at eight, and northern pikeminnow at seven. 

The remaining three species were found at one or two stations (Table 10). Bass were found at twelve stations total, 

and alternate predator species (northern pikeminnow, walleye, 

and rainbow trout) were collected at stations from which bass 

could not be obtained, with the exception of Station 506. Size 

and count data for non-target species were summarized but not 

discussed (Appendix 1). 

Total length, weight, and age were examined in bass from 

the CRB. The mean total length (TL) of bass from the CRB 

was 339 mm (range 220-522 mm) and mean weight was 728 

g (range 114-2,600 g) (Table 11). The mean age for all bass 

collected was 5.1 y (range 3-12 y). Females outweighed males 

(808 g vs. 640 g) and were longer (348 mm vs. 329 mm) and 

older (5.3 y vs. 4.9 y). Male and female bass were generally 

smallest (mean TL and weight) at Station 42 and largest at 

Stations 503 and 502, respectively (Table 11). Smallmouth 

bass were collected at Stations 42, 43, and 503 while a mix of 

females of largemouth and smallmouth bass were collected at 

Stations 44, 45, 96, and 97, suggesting that species differences 

alone did not account for size variation. Mean female age was 

Table 9. Fish species collected from the Columbia River Basin in 1997. A total of 560 of fish were collected from 

16 stations. Target species are denoted by an asterisk (*). 

Species Collected # of individual collected # of stations at which 

collected Taxon grouping 

Common Carp* 157 9 Carp 

Largescale sucker 159 10 Sucker 

Largemouth bass* 80 8 Micropterus 

Longnose sucker 15 2 Sucker 

Northern pikeminnow 58 7 Ptychocheilus 

Rainbow trout 20 1 Trouts 

Smallmouth bass* 54 9 Micropterus 

Walleye 17 1 Stizostedion 
Results and Discussion 25 

Table 10. Number of fish collected organized by species, station, and gender in the Columbia 

River Basin in 1997. Stations are grouped by sub-basin and listed upstream to downstream. 

Station numbers are given in parenthesis. Species totals that include individual(s) of unknown 

gender are designated by an asterisk (*).—Continued 

Sub-basin, Station, and Species Males Females Species 

total Station total 

Upper Columbia River (UCR) 

Creston, MT (117) 44 

Largescale sucker 6 4 10 

Largemouth bass 10 11 21 

Longnose sucker 1 10 13* 

Northport, WA (504) 40 

Largescale sucker 10 10 20 

Rainbow trout 2 10 20* 

Grand Coulee, WA (98) 38 

Largescale sucker 10 10 20 

Longnose sucker 1 1 2 

Walleye 4 8 16* 

Snake River (SR) 

Hagerman, ID (41) 36 

Carp 10 10 20 

Largemouth bass 7 9 16 

Riggins, ID (43) 41 

Largescale sucker 9 11 20 

Northern pikeminnow 5 9 14 

Smallmouth bass 4 3 7 

Lewiston, ID (42) 30 

Carp 12 5 17 

Smallmouth bass 5 7 13* 

Ice Harbor Dam, WA (96) 28 

Carp 11 10 21 

Largemouth bass 1 0 1 

Smallmouth bass 2 4 6 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) 36 

Carp 11 10 21 

Northern pikeminnow 2 8 10 

Smallmouth bass 2 3 5 

Pasco, WA (97) 35 

Carp 9 11 20 

Largemouth bass 6 7 13 

Smallmouth bass 0 2 2 

Granger, WA (44) 41 

Carp 10 10 20 

Largemouth bass 2 4 6 

Northern pikeminnow 1 5 6 

Smallmouth bass 4 5 9 

Lower Columbia River (LCR) 

Cascade Locks, OR (46) 23 

Largescale sucker 9 11 21* 

Northern pikeminnow 0 2 2 
26 Environmental Contaminants and their Effects on Fish 

Table 10. Number of fish collected organized by species, station, and gender in the Columbia 

River Basin in 1997. Stations are grouped by sub-basin and listed upstream to downstream. 

Station numbers are given in parenthesis. Species totals that include individual(s) of unknown 

gender are designated by an asterisk (*).—Continued 

Sub-basin, Station, and Species Males Females Species 

total Station total 

Warrendale, OR (502) 38 

Carp 10 10 20 

Largescale sucker 0 3 3 

Largemouth bass 0 1 1 

 Northern pikeminnow 0 11 11 

Smallmouth bass 3 0 3 

Vancouver, WA (506) 22 

 Largescale sucker 10 11 21 

Smallmouth bass 1 0 1 

Oregon City, OR (45) 42 

Carp 10 4 14 

Largescale sucker 0 6 6 

 Largemouth bass 5 8 14* 

Smallmouth bass 1 7 8 

Portland, OR (505) 33 

 Largescale sucker 10 11 22* 

Largemouth bass 3 5 8 

Northern pikeminnow 0 2 2 

Walleye 0 1 1 

Beaver Army Terminal, OR (501) 33 

Carp 4 0 4 

 Largescale sucker 5 11 16 

 Northern pikeminnow 2 11 13 

lowest at Station 44 and highest at Station 117 whereas male 

mean age was lowest at Station 43 and highest at Stations 42, 

44, and 503. The mean age for females was greater than that 

for males with the exceptions of Stations 44 and 45. Mean age 

was not consistently related to mean size; that is, the oldest 

bass were not necessarily the largest, indicating growth rate 

differences among stations (Table 11). Overall, the average 

lengths, weights, and ages of bass from the CRB were similar 

to those obtained from the MRB in 1995 (Schmitt and others, 

2002a). Bass from the RGB also had similar lengths and 

weights but were younger (1.8 y) compared to bass from the 

CRB (5.1 y) (Schmitt and others, 2004). 

Total length, weight, and age were similar in carp 

throughout the CRB. The mean TL of carp was 534 mm 

(range 321-771 mm) and weighed 2,296 g (range 397-8,000 

g) (Table 12). The mean age for all carp collected was 4.5 y 

(range 2-12 y). Females outweighed males (2,739 g vs. 1,963 

g) and were longer (555 mm vs. 504 mm), but the average age 

for both female and male carp was between 4 and 5 y (4.9 y 

vs. 4.3 y). The largest male and female carp (mean TL and 

weight) were collected from Stations 45 and 96, and the smallest were collected from Station 41 (Table 12). Mean age was 

lowest at Station 41 and highest at Station 96 for female fish 

and Station 501 for male fish. As was true for bass, ranking of 

stations by mean age did not yield the same order as ranking 

by TL or weight, indicating differences in growth rates among 

stations. Overall, the average lengths and weights of carp 

from the CRB were similar to those obtained from the MRB 

in 1995 (Schmitt and others, 2002a); however, some CRB 

carp weighed less than carp of the same age collected in the 

MRB, indicating slower growth at some sites. Carp collected 

in the RGB in 1997 had similar lengths and weights but were 

generally (3.2 y) younger compared to carp in the CRB (4.5 

y) (Schmitt and others, 2004), a pattern that was also found in 

bass. 

Some differences in TL, weight, and age existed between 

male and female largescale sucker from the CRB. Largescale sucker averaged 473 mm in TL (range 310-592 mm) and 

weighed 1037 g (range 146-2,100 g) (Table 13). The mean 

age for all largescale sucker collected was 4.4 y (range 3-10 

y). Females outweighed males (1,167 g vs. 890 g) and were 

longer (494 mm vs. 448 mm). The mean ages for females and 

males were similar (4.5 y vs. 4.3 y). Male and female largescale sucker were generally smallest (mean TL and weight) 

at Stations 501 and 505 and largest at Station 504 (Table 13). 

Average weights and lengths for largescale sucker were relatively consistent compared to carp and bass. Mean ages were 

lowest for male and female largescale sucker at Station 46 and 
-- -- -- -- -- -- 

-- -- -- -- -- -- -- 

-- -- -- -- -- -- -- -- -- 

-- -- -- -- -- -- 

-- -- -- -- -- 

Results and Discussion 27 

Table 11. Lengths, weights, and ages of bass collected in the Columbia River Basin in 1997. Stations are grouped by sub-basin 

and listed upstream to downstream. Station numbers are given in parentheses. Sample size (n), arithmetic mean, standard 

deviation (SD), and range are also given. Fish in which gender could not be determined are identified as having no gonad (NG). 

Sub-basin and Length (mm) Weight (g) Age (years) Gender Station n Mean SD Range n Mean SD Range n Mean SD Range 

Entire Basin All 134 339 72.7 220-522 134 728 578 114-2600 132 5.1 1.63 3-12 

F 76 348 76.1 224-522 76 808 640 147-2600 74 5.3 1.77 3-12 

M 56 329 67.7 220-488 56 640 484 114-2200 56 4.9 1.43 3-8 

NG 2 291 40.3 262-319 2 376 211 226-525 2 6.0 0.00 6 

Upper Columbia River (UCR)

Creston, MT (117) F 11 412 79.1 279-496 11 1354 757 280-2600 10 7.1 2.91 3-12 

M 10 339 70.5 252-461 10 756 627 114-1880 10 4.8 1.75 3-8 

Snake River (SR) 

Hagerman, ID (41) F 9 365 68.3 257-492 9 891 511 253-2000 9 5.0 1.00 3-6 

M 7 344 33.5 314-397 7 673 210 444-970 7 4.4 0.98 3-6 

Riggins, ID (43) F 3 309 22.5 293-335 3 433 107 310-500 3 4.3 0.58 4-5 

M 4 271 26.9 247-308 4 273 91 140-350 4 4.0 1.15 3-5 

Lewiston, ID (42) F 7 251 21.6 224-269 7 216 55 147-283 7 4.8 1.30 3-6 

M 5 250 21.1 220-289 5 212 57 142-319 5 4.1 0.90 3-6 

NG 1 262 1 226 1 6.0 

Ice Harbor Dam, WA F 4 375 47.3 311-412 4 856 325 425-1150 4 5.3 0.96 4-6 

(96) M 3 388 87.2 330-488 3 1170 904 510-2200 3 5.0 1.00 4-6 

Middle Columbia River (MCR) 

Vernita Bridge, WA F 3 470 9.2 460-478 3 1859 170 1726-2050 3 7.0 1.00 6-8 

(503) M 2 457 26.2 438-475 2 1637 513 1274-2000 2 6.0 0.00 6 

Pasco, WA (97) F 9 338 84.0 251-522 9 783 776 204-2600 9 4.6 1.51 3-7 

M 6 314 87.3 240-440 6 534 476 144-1248 6 4.3 1.51 3-7 

Granger, WA (44) F 9 316 68.9 254-450 9 591 528 212-1803 9 4.0 0.87 3-5 

M 6 353 48.1 285-418 6 700 286 362-1138 6 5.8 0.75 5-7 

Lower Columbia River (LCR)

Warrendale, OR F 1 497 1 2550 0 

(502) M 3 363 35.2 326-396 3 781 250 535-1035 3 4.3 0.58 4-5 

Vancouver, WA F 0 0 0 

(506) M 1 380 1 897 1 5.0 

Oregon City, OR (45) F 15 321 41.1 255-383 15 513 208 235-831 15 5.6 1.18 4-8 

M 6 338 51.6 292-432 6 620 358 382-1306 6 6.5 1.52 4-8 

NG 1 319 1 525 1 6.0 6 

Portland, OR (505) F 5 328 29.5 280-355 5 571 189 306-758 5 5.4 1.14 4-7 

M 3 286 43.5 255-336 3 373 192 224-590 3 4.3 2.31 3-7 

highest at Station 98. Ranking of stations by mean age did not 

yield similar order to ranking by TL or weight, indicating differences in growth rates among stations for largescale sucker 

(Table 13). 
-- -- -- -- -- -- -- -- -- 

28 Environmental Contaminants and their Effects on Fish 

Table 12. Lengths, weights, and ages of common carp collected in the Columbia River Basin in 1997. Stations are grouped by sub-basin and 

listed upstream to downstream. Station numbers are given in parentheses. Sample size (n), arithmetic mean, standard deviation (SD), and 

range are also given. 

Sub-basin and 

Station 

Gender 

n 

Length (mm) 

Mean SD Range n 

Weight (g) 

Mean SD Range n 

Age (years) 

Mean SD Range 

Entire Basin All 157 534 93.6 321-771 157 2296 1310 397-8000 133 4.5 1.45 2-12 

F 69 557 102 355-771 69 2739 1603 603-8000 57 4.9 1.75 3-12 

M 87 516 83.7 321-677 87 1963 894 397-4000 75 4.3 1.13 2-8 

Snake River (SR) 

Hagerman, ID F 10 399 38.3 355-464 10 892 255 603-1289 9 3.4 0.53 3-4 

(41) M 10 364 27.4 321-406 10 683 171 397-900 10 3.3 0.48 3-4 

Lewiston, ID F 5 615 21.2 585-639 5 3540 462 2900-4200 3 5.3 0.58 5-6 

(42) M 12 547 50.6 440-601 12 2479 641 1300-3300 8 4.1 0.83 3-5 

Ice Harbor F 10 654 73.7 535-745 11 4219 1743 2150-6738 9 6.3 3.20 3-12 

Dam, WA (96) M 11 595 38.4 560-667 11 2891 579 2200-4000 9 4.9 1.36 3-7 

Middle Columbia River (MCR) 

Vernita Bridge, F 10 607 61.0 475-661 10 3178 961 1376-4550 7 5.4 1.62 4-8 

WA (503) M 11 523 84.2 416-667 11 1853 744 917-2950 11 3.7 0.65 3-5 

Pasco, WA (97) F 11 518 64.4 439-626 11 2041 855 1105-3750 10 5.1 1.79 3-9 

M 9 501 36.5 461-581 9 1473 313 1200-2200 9 4.8 1.39 4-8 

Granger, WA F 10 520 59.2 428-615 10 1818 676 898-3150 8 4.0 0.53 3-5 

(44) M 10 489 43.1 444-590 10 1437 442 1038-2500 7 4.0 1.15 2-5 

Lower Columbia River (LCR) 

Warrendale, OR F 10 572 61.6 500-696 10 2724 972 1670-4500 8 5.0 0.93 4-6 

(502) M 10 514 64.1 383-625 10 1961 699 819-3400 9 4.9 1.05 4-7 

Oregon City, F 4 677 107 562-771 4 5313 2504 2650-8000 4 4.8 0.50 4-5 

OR (45) M 10 563 67.3 465-677 10 2586 910 1351-3800 8 4.6 0.74 4-6 

Beaver Army F 0 0 0 

Terminal, OR M 4 548 64.3 499-642 4 2223 889 1436-3500 4 5.0 1.41 3-6 

(501)

Accumulative contaminants, H4IIE Bioassay, 

and EROD Activity 

Elemental Contaminants 

Arsenic 

Concentrations of As were >LOD (0.21-0.31 μg/g ww) 

in 16 samples (25%) from nine stations (Fig. 3). The highest 

concentrations (0.52-0.56 μg/g ww) were in fish from Stations 

96, 504, and 505, with the maximum concentration occurring in male carp from Station 96 (Table 14; Fig. 3). Geometric mean concentrations of As were greatest at Stations 502 

(0.31 μg/g ww) and 96 (0.37 μg/g ww) (Table 15). 

Among-station differences for concentrations of As were 

significant in bass and carp but not in northern pikeminnow 

or largescale sucker (Table 16). Concentrations of As in bass 

were significantly greater at Stations 502 and 505 than at Station 42, and concentrations of As in carp were significantly 

greater at Station 96 than at Stations 41, 45, and 503 (Table 

16; Fig. 3). 

Concentrations of As changed significantly over time 

at several stations in collections from 1971-1997 (Table 17). 

Concentrations in carp at Stations 96, 97, 44, and 45, largescale sucker at Stations 98, 46, and 45, and bass at Stations 

43 and 44 differed significantly from 1997 values (Table 17). 

Increasing or decreasing temporal trends were not evident in 

concentrations at any station with the exception of bass from 

Station 43 which had increasing concentrations of As (0.13 

μg/g ww in 1971 to 0.22 μg/g ww in 1997) (Table 17). NCBP 

composite concentrations of As did not exceed 0.5 μg/g ww 
-- -- -- -- -- -- 

-- -- -- -- -- -- -- -- -- 

-- -- -- -- -- -- -- -- -- 

-- -- -- -- -- -- 

Results and Discussion 29 

Table 13. Lengths, weights, and ages of largescale sucker collected in the Columbia River Basin in 1997. Stations are grouped by subbasin and listed upstream to downstream. Station numbers are given in parenthesis. Sample size (n), arithmetic mean, standard 

deviation (SD), and range are also given. Fish in which gender could not be determined are listed as juvenile (J). 

Sub-basin 

and Station Gender 

n 

Length (mm) 

Mean SD Range n 

Weight (g) 

Mean SD Range n 

Age (years) 

Mean SD Range 

Entire Basin All 159 473 56.5 310-592 159 1037 378 146-2100 152 4.4 0.97 3-10 

F 88 494 55.4 370-592 88 1167 384 482-2100 85 4.5 1.05 3-10 

M 69 448 43.5 334-544 69 890 297 331-1754 65 4.3 0.82 3-6 

J 2 393 117 310-476 2 429 400 146-712 2 3.0 0.00 3 

Upper Columbia River (UCR) 

Creston, MT F 4 531 21.5 501-551 4 1479 216 1237-1762 4 4.3 0.50 3-5 

(117) M 6 453 30.1 410-504 6 909 270 597-1306 4 4.3 0.50 4-5 

Northport, F 10 552 23.4 514-592 10 1712 226 1223-2100 10 4.6 0.70 3-5 

WA (504) M 10 511 23.5 472-544 10 1408 177 1115-1754 10 4.8 0.42 4-5 

Grand F 10 552 24.5 517-592 10 1379 215 1156-1865 10 5.4 2.2 3-10 

Coulee, WA M 10 482 15.0 458-507 10 1015 133 732-1183 9 5.2 0.67 4-6 

(98)

Snake River (SR) 

Riggins, ID F 11 479 24.7 435-516 11 998 146 725-1200 10 4.4 0.52 4-5 

(43) M 9 436 22.3 416-485 9 781 88 700-975 9 3.8 0.83 3-5 

Lower Columbia River (LCR) 

Cascade F 11 544 24.9 508-592 11 1542 189 1264-1892 11 3.6 0.67 3-5 

Locks, OR M 9 462 23.2 418-494 9 982 152 799-1236 9 3.6 0.73 3-5 

(46) J 1 476 1 712 1 3.0 

Warrendale, F 3 472 37.2 441-513 3 964 218 827-1216 3 4.7 0.58 4-5 

OR (502) M 0 0 0 

Vancouver, F 11 469 37.9 395-503 11 1021 264 536-1472 11 5.0 0.45 4-6 

WA (506) M 10 408 32.5 334-442 10 631 134 331-803 10 4.0 0.67 3-5 

Oregon City, F 6 438 23.6 409-469 6 1020 282 812-1570 6 4.7 0.82 4-6 

OR (45) M 0 0 0 

Portland, OR F 11 453 49.1 370-565 11 767 143 482-1032 11 4.5 0.52 4-5 

(505) M 10 409 25.3 375-445 10 645 118 458-866 10 4.4 0.52 4-5 

J 1 310 1 146 1 3 

Beaver F 11 444 47.2 374-515 11 826 250 485-1149 9 4.0 0.87 3-5 

Army M 5 407 7.7 396-414 5 627 41 578-688 4 3.8 0.50 3-4 

Terminal 

(501)

from 1980-1986; concentrations >0.2 μg/g ww were measured 

in fish samples from Stations 41, 44, 46, 96, and 98 (Schmitt 

and others, 1999b). The USEPA measured whole body concentrations of As in smallmouth bass and largescale sucker, 

and concentrations ranged from 0.16-0.17 μg/g ww and 

0.074-0.32 μg/g ww, respectively, in the CRB from 1996-1998 

(USEPA, 2002b). Concentrations of As in bass and carp were 

measured in previous BEST projects in the MRB and RGB. 

Concentrations of As in bass ranged from 0.10-0.57 μg/g ww 

in the MRB (Schmitt and others, 2002b) and 0.04-0.25 μg/g 

ww in the RGB (Schmitt and others, 2004). Carp had concentrations of As ranging from 0.12-0.32 μg/g ww in the MRB 

(Schmitt and others, 2002b) and 0.05-0.55 μg/g ww in RGB 

(Schmitt and others, 2004), concentrations similar to those 

measured in the CRB. 

Arsenic tends to accumulate in planktivorous clupeids such as gizzard shad (Dorosoma cepedianum) and also 

sculpins (Cottus sp.) to a greater degree than in other fishes 

(Hunter and others, 1981; Schmitt and Brumbaugh, 1990; 

Wagemann and others, 1978) and can be further accumulated 
30 Environmental Contaminants and their Effects on Fish 

0.8 

0.6 

0.4 

0.2 

0 

1.2 

1 

0.8 

0.6 

0.4 

0.2 

0 

As 

Bass 

Sucker 

117 504 98 41 43 42 96 503 97 44 46 502 506 45 505 501 

Se 

Common Carp 

Pikeminnow 

Walleye 

Trout 

Upper Columbia R. Snake R. Mid-Columbia R. Lower Columbia R. 

μg/g μg/g 

Station 

Figure 3. Concentrations (μg/g ww) of arsenic (As) and selenium 

(Se) by station and taxon in whole body fish composite samples 

collected in the Columbia River Basin in 1997. Censored values are plotted as one half the LOD. Stations are ordered from 

upstream to downstream and are grouped by sub-basin. See 

Table 3 for station descriptions. 

by piscivores (Hunter and others, 1981). The occurrence 

of planktivorous clupeids at some sites and the dynamics of 

the ecosystems in which they occur may therefore confound 

trends for As. Schmitt and others (2002b) speculated that 

the comparatively high concentrations of As in largemouth 

bass from the southern parts of the MRB, especially in storage impoundments and the river systems containing them, at 

least partly reflected the presence of gizzard shad and other 

planktivorous clupeids. Ecosystem and hydrologic differences 

among stations may also partly explain the varying concentrations in carp and bass from the CRB. 

The concentrations of As detected in the freshwater 

fishes collected from the CRB in 1997 (0.14–0.56 μg/g ww) 

are not considered a hazard to the fish, piscivorous fishes, or 

wildlife (USEPA, 1984). A review by Jarvinen and Ankley 

(1999) included several laboratory studies in which effects of 

As were evaluated relative to whole body concentrations. For 

example, concentrations of 8.1-13.5 μg/g ww were associated 

with loss of equilibrium and 5.4 μg/g ww caused increased 

mortality in rainbow trout fingerlings (McGreachy and Dixon, 

1990; 1992). Adult bluegill experienced reduced survival and 

growth at 11.6 μg/g ww (Gilderhus, 1966). Concentrations in 

all fish from the CRB were less than these effect levels. 

Selenium 

Detectable concentrations of Se (>0.2 μg/g ww) were 

present at all stations in 55 of 64 composites (86%), with the 

maximum concentration measured in female carp from Station 

97 (Table 14). Concentrations ranged from 0.19-1.10 μg/g ww 

with concentrations ≥0.5 μg/g ww in composite samples from 

Stations 41, 42, 43, 44, 96, 97, 502, and 503 (Fig. 3). Concentrations of Se were generally greatest in carp and bass (Fig. 3). 

The geometric station mean for Se was greatest in fish samples 

from Station 97 (0.89 μg/g ww) followed by Stations 41 and 

503 (Table 15); station means for all other fish samples from 

were <0.50 μg/g ww. 

Among-station differences for concentrations of Se 

were significant in carp, largescale sucker, and bass but not in 

northern pikeminnow (Table 16). Concentrations in carp were 

significantly greater at Stations 45 and 97 than at Stations 41 

and 42 (Table 16; Fig. 3), and concentrations at Station 97 

were also significantly greater than Station 45. Concentrations 

of Se in largescale sucker were significantly greater at Stations 

43, 46, 98, 501 and 506 than at Station 45 (Table 16; Fig. 3). 

Concentrations in bass were significantly lower at Stations 45 

and 117 than at all other stations, and Stations 43, 97, and 503 

had concentrations of Se that were significantly greater than 

Stations 42, 44, and 505 (Table 16; Fig. 3). 

Concentrations of Se changed significantly from 1972­

1997 at several stations based on historical NCBP data (Table 

17). Concentrations in carp at Stations 42 and 97, largescale 

sucker at Stations 98, 46, and 45, bass at Station 44, and 

northern pikeminnow from Station 43 differed significantly 

from historical concentrations (Table 17). However, clear 

increasing or decreasing temporal trends were not evident at 

any of these stations (Table 17). Concentrations in 1997 were 

generally within the range of 1980-1986 NCBP concentrations 

(0.1-1.2 μg/g ww), with carp concentrations from Station 97 

remaining at approximately 1 μg/g ww (Schmitt and others, 

1999b). Walsh and others (1977) found similar concentrations 

of Se in largescale sucker and northern pikeminnow from the 

LCR. The USEPA determined whole body concentrations for 

Se in smallmouth bass and largescale sucker to range from 

0.48-0.71 μg/g ww and <0.18-0.50 μg/g ww, respectively, in 

the CRB from 1996-1998 (USEPA, 2002b). Munn and others (1995) measured concentrations of Se <0.2 μg/g ww in 

rainbow trout fillets from the UCR. Previous BEST projects 

measured concentrations of Se in bass and carp. Bass concentrations ranged from 0.20-4.46 μg/g ww in the MRB (Schmitt 

and others, 2002) and 0.47-1.23 μg/g ww in the RGB (Schmitt 

and others, 2004). Carp collected in 1995 from the MRB had 

concentrations of Se ranging from 0.12-4.66 μg/g ww (Schmitt 
31 

Table 14. Occurrence (percentages of samples or stations) and censoring concentrations for elemental contaminants in composite samples of whole fish from the Columbia 

River Basin in 1997. The maximum concentrations and associated sample information (station, species, and gender) from this study are also given. NA, not applicable. 

Analyte Samples Stations Censoring range Maximum 1997 concentration (% of 64) (% of 16) (μg/g) (μg/g) Station Gender Species ArsenicCadmiumChromiumCopperLeadMercuryNickelSeleniumZinc 

25

42

100

100

23

92

38

86

100 

56

75

100

100

50

100

81

100

100 

0.21-0.32

0.04-0.06

NA

NA

0.09-0.14

0.05-0.06

0.22-0.33

0.22-0.27

NA 

0.56

0.51

11.20

3.92

9.29

0.61

1.18

1.10

105.6 

Ice Harbor Dam, WA (96) 

Vernita Bridge, WA (503) 

Vancouver, WA (506) 

Ice Harbor Dam, WA (96) 

Northport, WA (504) 

Riggins, ID (43)

Vancouver, WA (506) 

Pasco, WA (97)

Oregon City, OR (45) 

M Carp 

F Carp 

M Largescale sucker 

M Carp 

F Largescale sucker 

F Northern pikeminnow 

F Largescale sucker 

F Carp 

F Carp 

and others, 2002b), and concentrations from the RGB ranged 

from 0.23-1.73 μg/g ww (Schmitt and others, 2004). 

Several Se studies were included in a review by Jarvinen 

and Ankley (1999) on the effects of inorganic chemicals to 

aquatic organisms. Various studies from this review have 

shown that whole body concentrations of Se between 8-16 

μg/g dw have led to reproductive failure in fathead minnows (Pimephales promelas) (Schultz and Hermanutz, 1990) and 

bluegill (Coyle and others, 1993; Gillespie and Baumann, 

1986; Hermanutz and others, 1992). Results from Coyle 

and others (1993) indicated that concentrations of Se present 

in the egg stage or at hatch affected larval survival. These 

results indicate it is essential to examine multiple life stages 

to correctly assess toxicity/tissue concentration relationships 

(Jarvinen and Ankley, 1999). Whole body concentrations of 

Se should not exceed 4 μg/g dw (0.8 μg/g ww assuming 80% 

moisture) to avoid toxicity to the fish and should not exceed 3 

μg/g dw (0.6 μg/g ww assuming 80% moisture) to avoid toxicity to piscivorous wildlife according to the criteria of Lemly 

(1996). Smallmouth bass at Stations 43 and 503 and carp and 

largemouth bass at Station 97 exceeded one or both thresholds. 

Mercury 

Mercury was detected (>0.05 μg/g ww) from all stations 

in 59 of 64 samples with the maximum concentration (0.61 μg/ 

g ww) measured in female northern pikeminnow from Station 

43 (Table 14). Concentrations were >0.25 μg/g ww in samples 

from Stations 43, 44, 45, 117, 501, 502, 503, and 505 (Fig. 4). 

The geometric mean was greatest at Station 43 (0.34 μg/g ww) 

followed by Stations 117 (0.24 μg/g ww) and 44 (0.23 μg/g 

ww) (Table 15). Concentrations were greatest in predatory 

fishes (Fig. 4). 

Predatory fish (bass, northern pikeminnow) accumulate 

greater concentrations of Hg than bottom feeding fish (carp, 

sucker) (Fig. 4) (Schmitt and others, 1999b), and concentrations in predatory fish increase with size (that is, heavier and 

longer fish have greater concentrations of Hg). Therefore, it 

becomes necessary to examine concentration of Hg adjusted 

for weight and length. It is difficult to relate the concentrations of Hg in composite samples to individual length and 

weight measurements, but overall trends or patterns can be 

identified. The length or weight adjusted concentrations of Hg 

in fish were greater (many >0.5 μg/g ww) than the unadjusted 

concentrations (only one >0.5 μg/g ww) (Fig. 4). 

Concentrations of Hg in bass and carp differed significantly among stations (Table 16). Un-adjusted concentrations 

of Hg in bass were significantly greater at Stations 43, 45, and 

117 than at Station 97 in carp (Table 16; Fig. 4). Un-adjusted 

concentrations of Hg were significantly greater at Stations 

42, 44, and 45 than at Stations 41 and 97 (Table 16; Fig. 

4). The weight-adjusted (HgW) and length-adjusted (HgL) 

concentrations of Hg did not differ significantly among stations for northern pikeminnow or largescale sucker; however, 

differences in bass and carp were significant (Table 16). The 

Results and Discussion 
Continued

32 Environmental Contaminants and their Effects on Fish 

Table 15. Geometric mean, minimum, and maximum concentrations (μg/g, wet-weight) of elemental contaminants in fish collected in 

the Columbia River Basin in 1997. Censored values were replaced by one-half the value for the LOD for the computation of station 

means, but only if at least one value exceeded detection limits. The maximum geometric station mean is shown in bold for each 

contaminant. Stations are grouped by sub-basin and are ordered upstream to downstream.— 

Element Station As Cd Cr Cu Hg Ni Pb Se Zn 

Upper Columbia River (UCR) 

Creston, MT (117) 

(n = 4) 

Northport, WA (504) 

(n = 4) 

Grand Coulee, WA (98) 

(n = 3) 

Snake River (SR) 

Hagerman, ID (41) 

(n = 4) 

Riggins, ID (43) 

(n = 5) 

Lewiston, ID (42) 

(n = 4) 

Ice Harbor Dam, WA, (96) 

(n = 4) 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) 

(n = 4) 

Pasco, WA (97) 

(n = 4) 

Granger, WA (44) 

(n = 6) 

Lower Columbia River (LCR) 

Cascade Locks, OR (46) 

(n = 2) 

Mean 

Min. 

Max. 

Mean 

Min. 

Max. 

Mean 

Min. 

Max. 

Mean 

Min. 

Max. 

Mean 

Min. 

Max. 

Mean 

Min. 

Max. 

Mean 

Min. 

Max. 

Mean 

Min. 

Max. 

Mean 

Min. 

Max. 

Mean 

Min. 

Max. 

Mean 

Min. 

Max. 

<0.28 

<0.23 

<0.28 

0.19 

<0.26 

0.52 

<0.25 

<0.21 

<0.25 

<0.30 

<0.25 

<0.30 

0.15 

<0.23 

0.41 

<0.32 

<0.26 

<0.32 

0.37 

0.27 

0.56 

0.14 

<0.26 

<0.30 

0.16 

<0.24 

0.32 

0.15 

<0.25 

0.43 

<0.26 

<0.23 

<0.26 

0.03 

<0.05 

0.05 

0.10 

<0.05 

0.42 

0.10 

<0.05 

0.46 

<0.06 

<0.05 

<0.06 

0.05 

<0.05 

0.08 

0.04 

<0.05 

0.11 

0.07 

<0.05 

0.27 

0.12 

<0.06 

0.51 

0.09 

<0.05 

0.39 

<0.06 

<0.05 

<0.06 

0.08 

0.06 

0.10 

0.69 

0.50 

1.06 

1.08 

0.43 

3.42 

0.75 

0.52 

2.15 

1.72 

0.91 

3.70 

0.73 

0.38 

2.47 

0.76 

0.69 

0.85 

1.27 

0.80 

3.96 

1.51 

0.50 

3.38 

1.87 

0.66 

3.72 

1.41 

0.53 

3.22 

1.87 

1.25 

2.78 

0.62 

0.40 

0.96 

1.71 

1.10 

3.46 

0.83 

0.53 

1.36 

0.81 

0.44 

1.32 

0.87 

0.71 

1.01 

0.82 

0.50 

1.07 

1.24 

0.49 

3.92 

1.68 

0.92 

3.32 

0.90 

0.47 

1.55 

0.89 

0.51 

1.65 

1.07 

0.97 

1.19 

0.24 

0.20 

0.31 

0.06 

<0.05 

0.15 

0.13 

0.12 

0.15 

0.07 

<0.05 

0.24 

0.34 

0.15 

0.61 

0.18 

0.14 

0.21 

0.12 

0.10 

0.20 

0.16 

0.08 

0.30 

0.07 

<0.05 

0.18 

0.23 

0.16 

0.48 

0.11 

0.10 

0.13 

<0.27 <0.11 <0.30 19.4 

<0.22 <0.09 <0.24 16.0 

<0.27 <0.11 <0.30 23.6 

0.31 1.25 0.29 31.9 

<0.27 0.22 <0.26 19.5 

0.74 9.29 0.43 50.9 

0.21 0.23 0.31 22.5 

<0.25 <0.10 0.30 14.3 

0.56 1.58 0.32 36.0 

0.17 <0.12 0.51 35.7 

<0.27 <0.10 0.50 16.5 

0.27 <0.12 0.54 77.0 

0.19 0.07 0.48 19.9 

<0.24 <0.10 0.24 17.3 

0.58 0.17 0.84 24.1 

<0.32 <0.13 0.36 33.3 

<0.26 <0.10 0.27 15.9 

<0.32 <0.13 0.50 66.8 

0.24 <0.14 0.48 28.6 

<0.26 <0.10 0.44 11.6 

0.47 <0.14 0.54 71.4 

0.29 0.09 0.52 27.5 

<0.27 <0.10 0.41 14.4 

0.59 0.33 0.70 75.5 

0.28 0.07 0.89 38.3 

<0.24 <0.09 0.80 15.1 

0.75 0.14 1.10 104.5 

0.18 <0.11 0.34 23.4 

<0.25 <0.10 0.28 14.6 

0.46 <0.11 0.53 80.9 

0.61 0.07 0.30 21.9 

0.53 <0.1 0.26 19.6 

0.69 0.11 0.35 24.5 
Results and Discussion 33 

Table 15. Geometric mean, minimum, and maximum concentrations (μg/g, wet-weight) of elemental contaminants in fish collected in 

the Columbia River Basin in 1997. Censored values were replaced by one-half the value for the LOD for the computation of station 

means, but only if at least one value exceeded detection limits. The maximum geometric station mean is shown in bold for each 

contaminant. Stations are grouped by sub-basin and are ordered upstream to downstream.—Continued 

Element Station As Cd Cr Cu Hg Ni Pb Se Zn 

Warrendale, OR (502) 

(n = 4) 

Mean 

Min. 

0.31 

<0.27 

0.08 

<0.05 

0.89 

0.61 

1.07 

0.58 

0.21 

0.07 

<0.27 

<0.27 

<0.11 

<0.11 

0.40 

0.28 

25.9 

12.4 

Max. 0.42 0.40 2.09 2.93 0.49 <0.27 <0.11 0.50 94.0 

Vancouver, WA (506) 

(n = 2) 

Mean 

Min. 

0.16 

0.14 

0.07 

0.05 

6.76 

4.08 

1.38 

1.19 

0.09 

0.08 

0.97 

0.80 

0.24 

0.22 

0.23 

0.19 

20.4 

19.5 

Max. 0.18 0.10 11.20 1.60 0.10 1.18 0.27 0.28 21.4 

Oregon City, OR (45) 

(n = 6) 

Mean 

Min. 

<0.28 

<0.22 

<0.06 

<0.04 

0.78 

0.52 

0.82 

0.53 

0.17 

0.10 

0.15 

<0.22 

<0.11 

<0.09 

<0.27 

<0.22 

24.3 

14.7 

Max. <0.28 <0.06 1.23 1.35 0.30 0.29 <0.11 <0.27 105.6 

Portland, OR (505) 

(n = 4) 

Mean 

Min. 

0.18 

<0.23 

0.02 

<0.05 

1.00 

0.30 

0.92 

0.34 

0.16 

0.11 

0.26 

<0.26 

0.07 

<0.09 

0.23 

<0.24 

16.5 

14.2 

Max. 0.53 <0.05 2.91 1.46 0.26 0.50 0.21 0.34 20.3 

Beaver Army Terminal, OR (501) 

(n = 4) 

Mean 

Min. 

0.20 

<0.22 

0.06 

<0.05 

1.27 

0.89 

1.15 

0.81 

0.16 

0.09 

0.18 

<0.25 

<0.11 

<0.09 

0.36 

0.29 

30.2 

17.6 

Max. 0.42 0.14 1.80 1.40 0.38 0.37 <0.11 0.46 82.0 

relative rankings of the stations for bass and northern pikeminnow was similar for Hg, HgL, and HgW (Table 16); however, 

the magnitude of the among-sample differences at each station 

were smaller for the adjusted values (Fig. 4), indicating that 

some of the observed differences were related to fish size. 

Nevertheless, most relative differences remained after adjusting for fish size, which suggests that spatial differences were 

not entirely artifacts of fish size. 

Concentrations of Hg in fish changed significantly from 

1969-1997 at several stations based on historical NCBP collections in the CRB (Table 17). These changes were fairly 

consistent for Hg, HgL, and HgW (Table 17). The size range 

of the bass from these stations was smaller than the range by 

the NAWQA Program’s National Hg pilot study (Brumbaugh 

and others, 2001) in which HgL and HgW were first used to 

normalize concentrations of Hg relative to fish size. Overall, 

concentrations of Hg in carp at Stations 42, 96, and 97, largescale sucker at Stations 117, 98, 43, 46, and 45, and northern pikeminnow from Station 43 differed significantly from 

historical concentrations (Table 17). Increasing or decreasing 

temporal trends were not evident at any of these stations. In 

addition, and as noted for the geographic differences, the 

ordering of the years within taxa was similar for Hg, HgL, and 

HgW (Table 17). These results indicate that the among-year 

concentration differences were also not overly influenced by 

differences in the sizes of the fish comprised by the samples. 

Concentrations of Hg in 1997 were comparable to those from 

1980-1986 when species differences are considered (Schmitt 

and others, 1999b). 

Several other studies have reported concentrations 

of Hg in the CRB. Walsh and others (1977) found similar concentrations of Hg in largescale sucker and northern 

pikeminnow from the LCR. Serdar and others (1994) measured concentrations of Hg ranging from 0.12-0.18 μg/g ww 

in largescale sucker collected near Station 504. The USEPA 

determined whole body concentrations of Hg in smallmouth 

bass and largescale sucker to range from 0.22-0.36 μg/g ww 

and <0.058-0.25 μg/g ww, respectively, in the CRB from 

1996-1998 (USEPA, 2002b). Concentrations of Hg ranged 

from 0.21-0.37 μg/g ww in composite walleye fillets from the 

UCR in 1994 (Munn and others, 1995). Concentrations of 

Hg <0.35 μg/g ww were documented in northern pikeminnow 

collected from Stations 42, 45, and 46 in the CRB from 1969­

1981 (Eisler, 1985; Lowe and others, 1985). Previous BEST 

projects have measured Hg in carp and bass. Concentrations 

of Hg ranged from 0.04-0.34 μg/g ww in carp and 0.05-0.45 

μg/g ww in bass in the MRB in 1995 (Schmitt and others, 

2002b). Similar concentrations of Hg were measured in carp 

(0.03-0.20 μg/g ww) and bass (0.07-0.45 μg/g ww) in the RGB 

(Schmitt and others, 2004). 

Many Hg toxicity studies in adult fish are not associated with environmentally relevant concentrations (Wiener 

and Spry, 1996). Fish populations are most at risk from 

Hg at existing exposure levels during embryonic and larval 
ontinued 

34 Table 16. Spatial trends of chemical contaminants in fish collected in the Columbia River Basin in 1997. Least-squares mean concentrations (all in μg/g ww unless otherwise noted) of 

arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), length-adjusted Hg (HgL; μg/g/m ww), weight-adjusted Hg (HgW; μg/g/kg ww), lead (Pb), selenium (Se), zinc (Zn), p,p’-DDE and PCB.

Values within each group of taxon-station means followed by the same letter are not significantly different (P<0.01 Fisher’s protected LSD). Also shown are ANOVA F-values, degrees-offreedom (df), and significance levels (*0.01<P0.05; **P0.01). Stations are listed upstream to downstream within each taxon grouping.—C 

Contaminant Station and species As Cd Cu Hg HgW HgL Pb Se Zn DDE PCB 

CarpHagerman, ID (41) Lewiston, ID (42) Ice Harbor Dam, WA (96) Verita Bridge, WA (503) Pasco, WA (97)Granger, WA (44) Warrendale, OR (502) Oregon City, OR (45) Beaver Army Terminal, OR (501) Largescale sucker Creston, MT (117) Northport, WA (504) Grand Coulee, WA (98) Riggins, ID (43)Ice Harbor Dam, WA (46) Vancouver, WA (506) Oregon City, OR (45) 

Portland, OR (505) Beaver Army Terminal, OR (501) 

BassCreston, MT (117) Hagerman, ID (41) Riggins, ID (43)Lewiston, ID (42) Ice Harbor Dam, WA (96) Vernita Bridge, WA (503) Pasco, WA (97)Granger, WA (44) Warrendale, OR (502) Oregon City, OR (45) Portland, OR (505) 

0.130 a 

0.152 ab 

0.453 b

0.139 a 

0.197 ab

0.238 ab 

0.238 ab 

0.131 a 

0.257 ab 

0.116

0.260

0.107

0.218

0.123

0.161

0.108

0.117

0.215

0.132 ab

0.148 ab 

0.127 ab

0.135 a 

0.306 ab 

0.147 ab

0.127 ab 

0.138 ab

0.400 b

0.123 ab 

0.265 b 

0.026 a 

0.060 ab 

0.188 c 

0.412 c 

0.345 c 

0.027 a 

0.294 c 

0.026 a 

0.135 bc 

0.033 ab 

0.375 c 

0.376 c 

0.066 ab 

0.076 b 

 0.069 ab 

0.022 ab 

0.023 a 

0.063 ab 

0.027

0.030

0.058

0.027

0.028

0.030

0.025

0.028

0.027

0.025

0.027 

1.082 ab 

0.959 a 

2.525 c 

2.219 bc 

1.534 abc 

1.578 abc 

2.220 bc 

1.237 abc 

1.402 abc 

0.898 a 

2.636 b 

1.299 ab 

0.873 a 

1.071 a 

1.384 ab 

1.080 ab 

1.422 ab 

1.343 ab 

0.429

0.612

1.007

0.707

0.611

0.919

0.534

0.605

0.577 

0.584

0.589 

0.026 a 

0.190 c 

0.100 bc 

0.091 bc 

0.045 ab 

0.163 c 

0.096 bc 

0.117 c 

0.115 bc 

0.209

0.111

0.120

0.171

0.115 

0.093

0.118

0.118

0.096

0.271 b 

0.178 ab 

0.443 b 

0.172 ab 

0.141 ab 

0.153 ab 

0.103 a 

0.188 ab 

0.192 ab 

0.251 b 

0.230 ab 

0.033 a 

0.064 ab 

0.029 a 

0.038 ab 

0.026 a 

0.101 b 

0.042 ab 

0.032 a 

0.052 ab 

0.181

0.072

0.101

0.194

0.095

0.115

0.115

0.167

0.133

0.268 abcd 

0.230 abc 

1.297 e 

0.759 de 

0.180 abc 

0.086 a 

0.161 ab 

0.340 bcd 

0.245 abcd 

0.457 cde 

0.498 cde 

0.068 a 

0.381 c 

0.160 abc

0.162 abc 

0.089 ab

0.323 c 

0.177 bc 

0.189 bc 

0.210 abc 

0.427

0.209

0.232

0.374

0.229

0.212

0.268

0.273

0.225

0.724 abc

0.504 abc 

1.542 c

0.668 abc 

0.391 ab 

0.328 ab

0.314 a 

0.578 abc

0.528 abc

0.766 bc 

0.750 abc 

0.052 a 

0.061 a 

0.062 a 

0.272 b 

0.086 a 

0.054 a 

0.054 a 

0.053 a 

0.051 a 

0.046 a 

6.169 e 

1.036 d 

0.130 bc 

0.073 ab 

0.243 c 

0.043 ab 

0.098 abc 

0.044 a 

0.053

0.059

0.051

0.054

0.057

0.059

0.051

0.055

0.055

0.049

0.053 

0.501 a 

0.400 a 

0.512 ab 

0.495 ab 

0.991 c 

0.355 ab 

0.458 ab 

0.380 b 

0.464 ab 

0.188 ab 

0.195 ab 

0.308 b 

0.268 b 

0.304 b 

0.233 b 

0.108 a 

0.170 ab 

0.300 b 

0.132 a 

0.521 bc 

0.838 c 

0.330 b 

0.448 bc 

0.698 c 

0.808 c 

0.375 b 

0.497 bc 

0.123 a 

0.317 b 

73.26 0.155 ab 0.015 a 

65.30 0.575 c 0.145 a 

65.18 0.802 c 0.234 b 

73.36 0.785 c 0.300 b 

86.96 0.251 ab 0.029 a 

78.33 0.668 bc 0.077 a 

81.84 0.290 abc 0.134 b 

75.63 0.100 a 0.312 b 

81.97 0.510 abc 0.250 b 

22.81 a 0.005 a 0.015 a 

48.23 b 0.020 a 0.156 cd 

35.40 b 0.012 a 0.015 ab 

22.07 a 0.194 bc 0.015 cd 

21.88 a 0.304 bc 0.103 d 

20.41 a 0.135 b 0.287 cd 

18.89 a 0.250 bc 0.015 bc 

18.93 a 0.096 b 0.209 d 

19.16 a 0.665 c 0.141 cd 

16.45 ab 0.005 a 0.015 a 

17.41 ab 0.350 bc 0.015 a 

17.26 ab 0.200 bc 0.015 a 

17.01 ab 0.110 b 0.184 b 

12.53 a 0.230 bc 0.026 a 

14.44 ab 0.510 bc 0.300 b 

16.83 ab 0.206 b 0.025 a 

15.28 b 0.817 c 0.223 b 

12.44 ab 0.180 bc 0.380 b 

15.98 ab 0.186 b 0.020 a 

14.37 ab 0.146 b 0.467 b 

Environmental Contaminants and their Effects on Fish 
35 

Table 16. Spatial trends of chemical contaminants in fish collected in the Columbia River Basin in 1997. Least-squares mean concentrations (all in μg/g ww unless otherwise noted) of 

arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), length-adjusted Hg (HgL; μg/g/m ww), weight-adjusted Hg (HgW; μg/g/kg ww), lead (Pb), selenium (Se), zinc (Zn), p,p’-DDE and PCB.

Values within each group of taxon-station means followed by the same letter are not significantly different (P<0.01 Fisher’s protected LSD). Also shown are ANOVA F-values, degrees-offreedom (df), and significance levels (*0.01<P0.05; **P0.01). Stations are listed upstream to downstream within each taxon grouping.—Continued 

Contaminant Station and species As Cd Cu Hg HgW HgL Pb Se Zn DDE PCB 

Northern pikeminnow

Riggins, ID (43)Vernita Bridge (503) Granger, WA (44) Warrendale, OR (502) Beaver Army Terminal, OR (501) F-valuedf (model, error)

0.122

0.128

0.125

0.299

0.135

5.45

156,93 

 0.036 ab 

 0.135 b 

 0.025 a 

0.054 ab 

0.027 a 

12.08

156,93 

0.759 a 

2.321 b 

1.035 ab 

0.949 ab 

0.806 ab 

4.44

80,56 

0.521

0.302

0.480

0.490

0.377

10.61

186,100 

0.831

0.291

0.798

0.428

0.460

11.45

186,100 

1.350

0.619

1.162

0.953

0.853

10.90

186,100 

0.049

0.051

0.050

0.053

0.054

10.11

123,70 

0.484

0.413

0.317

0.280

0.328 

9.26

156,93 

20.78

19.58

16.05

17.14

17.57

31.49

80,56 

 0.093 a 0.048 a 

 0.280 ab 1.300 c 

 0.800 b 0.170 b 

0.370 ab 0.680 bc 

0.220 ab 0.380 bc 

7.19 9.05 

209,112 93,64 

stages partially due to maternal transfer (Wiener and Spry, 

1996). Behavioral effects in laboratory studies have been 

documented in fish containing whole body concentrations of 

0.7-5.4 μg/g ww (Kania and O’Hara, 1974; Wiener and Spry, 

1996). Grayling (Thymallus thymallus) fry with 0.27 μg/g ww 

of Hg had permanent impairment of their feeding efficiency 

and competitive ability (Fjeld and others, 1998). Jarvinen and 

Ankley (1999) reviewed various laboratory studies evaluating 

the effects of Hg on reproduction in freshwater fish. Included 

were studies that found reduced reproduction at whole body 

concentrations of 4.47 μg/g ww in fathead minnows (Snarski 

and Olson, 1982) and 9.4 μg/g ww in second-generation brook 

trout (McKim and others, 1976). Concentrations of Hg in the 

diet of 0.87 μg/g dw increased whole body concentrations of 

Hg over 10-fold, and suppressed hormone levels and inhibited 

gonadal development in female fathead minnows (Drevnick 

and Sandheinrich, 2003). Whole body concentrations associated with behavioral and reproductive effects were approximately 5 μg/g ww for brook trout (Salvelinus fontinalis) and 

10 μg/g ww for rainbow trout (Wiener and Spry, 1996; Wiener 

and others, 2002). However, caution should be used with 

these thresholds because many factors can contribute uncertainty to these critical tissue concentration estimates (Wiener 

and others, 2002). 

Dietary intake of Hg is a concern for piscivorous wildlife 

because Hg bioaccumulates up the food chain. Dietary concentrations of Hg in wildlife as low as 0.3 μg/g ww have been 

associated with reproductive impairment in common loons (Gavia immer) (Barr, 1986), and reproduction in mallards (Anas platyrhynchos) was affected at concentrations as low as 

0.1 μg/g ww (Heinz, 1979). Dietary concentrations of Hg at 

0.25-1.0 μg/g ww may also be toxic to piscivorous mammals 

(studies reviewed by Wolfe and others, 1998). Neurotoxicity and mortality occurred in adult mink (Mustela vison) after 

chronic exposure to dietary concentrations of Hg >1 μg/g ww 

(Dansereau and others, 1999; Wobeser and others, 1976; Wren 

and others, 1987). Consequently, guidelines for the protection 

of piscivorous wildlife range from 0.5-1.0 μg/g ww (Eisler, 

1987; Thompson, 1996) and values as low as 0.1 μg/g ww for 

mammals and 0.02 μg/g ww for birds have been derived from 

water quality criteria and bioaccumulation factors (Yeardley 

and others, 1998). Selenium affords a degree of protection 

against Hg toxicity in wildlife by demethylation to inorganic 

mercury when Se and Hg are in molar ratio of 1:1 (Dietz and 

others, 1990; Heinz and Hoffman, 1998; Scheuhammer and 

others, 1998; Wiener and others, 2002). However, studies 

have shown Se-enhanced Hg embryo toxicity in birds (Heinz 

and Hoffman, 1998). Reproductive effects may be exacerbated, even though the significant amounts of Se may protect 

adult birds from the toxic effects of Hg. Concentrations of Hg 

in largemouth bass at Station 117, smallmouth bass from Station 43, and northern pikeminnow from Stations 43, 44, 501, 

502, and 503 exceeded 0.3 μg/g ww, and at least one sample 

from all stations exceeded 0.1 μg/g ww (Fig. 4). Therefore, 

our results indicate that Hg is a contaminant of concern in the 

CRB. 

Results and Discussion 
Continued

36 

Table 17. Historical trends of chemical contaminants in fish collected from NCBP stations in the Columbia River Basin. Least-squares mean concentrations (all in μg/g ww unless 

otherwise noted) of arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), length-adjusted Hg (HgL; μg/g/m ww), weight-adjusted Hg (HgW; μg/g/kg ww), selenium (Se), lead (Pb), zinc (Zn), p,p’-DDE, and PCB. Values within each group of taxon-station means followed asterisks differ significantly (*0.01<P0.05; **P0.01, Fisher’s protected LSD) from 1997 means. Also 

shown are ANOVA F-values, degrees-of-freedom (df), and significance levels. ND, no data/not measured. Stations are listed upstream to downstream within each taxon grouping.— 

Station and Year Contaminant 

Species As Cd Cu Hg HgW HgL Se Pb Zn DDE PCBs 

CarpHagerman, ID 1974 ND (41) 1997 0.130 Lewiston, ID 1970 ND (42) 1971 0.074 

1972 0.140 

1973 0.180 1997 0.152 

Ice Harbor Dam, 1971 0.106 ** WA (96) 1997 0.453 Pasco, WA (97) 1970 ND 

1971 0.039 ** 

1972 0.120 1973 0.180 

1974 ND 

1976 0.296 

1980 0.069 * 

1997 0.197 

Granger, WA 1970 ND (44) 1971 0.039 ** 

1972 0.200 1973 0.025 ** 1974 ND 1978 0.170 

1997 0.238 

Oregon City, OR 1970 ND (45) 1973 0.025 ** 

ND

0.026

ND

0.047

0.880 ** 

0.060

0.060

0.074 * 

0.188

ND

0.098 ** 

1.800 ** 

0.025 ** 

ND

0.050 ** 

0.049 ** 

0.345

ND

0.025

0.420 **

0.025

ND

0.050

0.027

ND

0.025 

ND

1.082

ND

ND

ND

ND

0.959

ND

2.525

ND

ND

ND

ND

ND

ND

1.374

1.534

ND

ND

ND

ND

ND

1.187

1.578

ND

ND 

ND

0.026

0.250

0.300

0.170

0.060 * 

0.190

0.214 * 

0.100

0.070

0.075

0.120 * 

0.005 ** 

ND

0.020 * 

0.045

0.045

0.230

0.171

0.240

0.070

ND

0.215

0.163

0.170

0.150 

ND

0.033

0.240 ** 

0.302 ** 

0.121

0.049

0.064

0.294 ** 

0.029

0.119 ** 

 0.127 ** 

0.265 ** 

0.014

ND

0.063 * 

0.090 ** 

0.026

0.483 ** 

0.329 ** 

0.661 ** 

0.129

ND

0.433 ** 

0.101

0.075

0.254 ** 

ND

0.068

0.643

0.804 * 

0.391

 0.137 * 

 0.381

0.660 ** 

0.160

0.219 * 

0.241 ** 

0.387 ** 

0.016 ** 

ND

0.068

0.136

 0.089

0.805 * 

0.567

0.900 * 

0.206

ND

0.630

 0.323

0.352

0.413

ND

0.501

ND

ND

0.170 ** 

0.300

0.400

ND

0.512

ND

ND

0.400 ** 

0.668

ND

ND

0.832

0.991

ND

ND

0.400

0.220

ND

0.542

0.355

ND

0.180

ND

0.052

ND

0.110

0.050

0.050

0.061

0.074

0.062

ND

0.369 ** 

0.200

0.087

ND

0.210 * 

 0.288 ** 

0.086

ND

0.050

0.050

0.050

ND

 0.118 * 

0.054

ND

0.050 

ND 0.314 ND

 73.26 0.155 0.015 

ND 0.470 ND

ND 0.159 * ND 

ND 1.100 ND 

ND 0.310 ND 

65.30 0.575 0.145 

ND 0.405 ND

 65.18 0.802 0.234 

ND 1.120 * ND

ND 0.334 ND 

ND 0.670 ND 

ND 0.255 ND 

ND 1.543 ** ND 

ND 0.135 0.150 ** 

78.83 0.194 0.224 ** 

86.96 0.251 0.029 

ND 1.230 ND

 ND 1.045 ND 

ND 2.200 ND 

ND 0.520 ND 

ND 2.612 * ND 

92.46 1.215 0.524 ** 

78.33 0.668 0.077 

ND 0.340 ND

ND 0.350 ND 

Environmental Contaminants and their Effects on Fish 
37 

Table 17. Historical trends of chemical contaminants in fish collected from NCBP stations in the Columbia River Basin. Least-squares mean concentrations (all in μg/g ww unless 

otherwise noted) of arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), length-adjusted Hg (HgL; μg/g/m ww), weight-adjusted Hg (HgW; μg/g/kg ww), selenium (Se), lead (Pb), zinc (Zn), p,p’-DDE, and PCB. Values within each group of taxon-station means followed asterisks differ significantly (*0.01<P0.05; **P0.01, Fisher’s protected LSD) from 1997 means. Also 

shown are ANOVA F-values, degrees-of-freedom (df), and significance levels. ND, no data/not measured. Stations are listed upstream to downstream within each taxon grouping.— Continued

Station and Year Contaminant 

Species As Cd Cu Hg HgW HgL Se Pb Zn DDE PCBs 

1974 ND ND ND ND ND ND ND ND ND 0.880 ** ND 

1997 0.131 0.026 1.237 0.117 0.032 0.189 0.380 0.053 75.63 0.100 0.312 

Largescale sucker 

Creston, MT 1980 0.063 0.014 * 0.913 0.099 * 0.169 0.254 0.198 0.100 * 18.21 0.030 ** 0.200 ** (117) 1984 0.073 0.020 0.864 0.171

1986 0.117 0.020 3.143 ** 0.176

1997 0.116 0.033 0.898 0.209

0.165 0.395 0.180 0.063 20.09 0.014 0.173 ** 

0.155 0.366 0.172 0.101 * 19.72 0.014 0.075 ** 

0.181 0.427 0.188 0.046 22.81 0.005 0.015 

Northport, WA 1971 0.164 0.114 ** ND 0.049 * 0.103 0.145 ND 0.722 ND 0.052 * ND(504) 1976 0.300 0.330 ND 0.020 ** 

1978 0.200 0.357 0.849 0.0671980 0.281 * 0.216 0.837 0.125

1984 0.137 0.092 ** 1.040 0.088

1997 0.107 0.376 1.299 0.120

0.026 ** 0.046 ** ND 2.570 * ND 0.024 0.495 ** 

0.082 0.152 0.224 1.115 55.39 ** 0.040 * 0.474 ** 

0.153 0.294 0.195 * 0.653 28.07 0.055 ** 0.274 ** 

0.205 0.271 0.224 0.253 ** 21.05 ** 0.024 0.250 ** 

0.101 0.232 0.308 1.036 35.40 0.012 0.015 

Riggins, ID (43) 1969 ND ND ND

1970 ND ND ND1971 0.134 0.072 ND

1972 0.126 0.180 * ND1973 0.200 0.025 ND

1974 ND ND ND

1976 0.500 0.120 ND

1984 0.114 0.020 ** 0.816

1986 0.110 0.048 0.539

1997 0.218 0.066 0.873

Cascade Locks, 1969 

0.230 0.317 0.596 ND ND ND 0.140 ND0.405 * 0.388 0.908 * ND ND ND 0.110 ND 

0.262 0.330 0.662 ND 0.084 ND 0.229 ND 

0.113 0.200 0.316 0.224 0.141 ND 0.104 ND 

0.150 0.184 0.337 0.320 0.050 * ND 0.120 ND 

ND ND ND ND ND ND 0.180 ND 

0.190 0.246 0.411 ND 0.230 ND 0.130 0.194 ** 

0.098 0.206 0.267 0.299 0.154 20.97 0.014 ** 0.200 ** 

0.125 0.166 0.291 0.261 0.181 19.14 0.014 ** 0.075 ** 

0.171 0.194 0.374 0.268 0.130 22.07 0.194 0.015 

ND ND ND 0.270 0.298 * 0.644 * ND ND ND 0.360 ND

OR (46) 1970 ND ND ND 0.210

1971 0.183 0.025 ** ND 0.200

1972 0.025 ** 0.160 ND 0.230

1973 0.045 * 0.081 ND 0.320 ** 

1974 ND ND ND ND

0.231 0.489 ND ND ND 0.220 ND 

 0.245 * 0.492 * ND 0.145 ND 0.388 ND 

0.298 * 0.566 * 0.140 ** 0.100 ND 0.470 ND 

0.381 ** 0.714 ** 0.088 ** 0.353 ** ND 0.248 ND 

ND ND ND ND ND 0.200 ND 

Results and Discussion 
38 

Table 17. Historical trends of chemical contaminants in fish collected from NCBP stations in the Columbia River Basin. Least-squares mean concentrations (all in μg/g ww unless 

otherwise noted) of arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), length-adjusted Hg (HgL; μg/g/m ww), weight-adjusted Hg (HgW; μg/g/kg ww), selenium (Se), lead (Pb), zinc (Zn), p,p’-DDE, and PCB. Values within each group of taxon-station means followed asterisks differ significantly (*0.01<P0.05; **P0.01, Fisher’s protected LSD) from 1997 means. Also 

shown are ANOVA F-values, degrees-of-freedom (df), and significance levels. ND, no data/not measured. Stations are listed upstream to downstream within each taxon grouping.— Continued

Station and Year Contaminant 

Species As Cd Cu Hg HgW HgL Se Pb Zn DDE PCBs 

1976 0.870 ** 0.150 ND 0.050

1978 0.324 * 0.055 1.209 0.0741980 0.434 ** 0.030 * 0.903 0.071

1984 0.220 0.040 1.010 0.100

1997 0.123 0.076 1.071 0.115

0.138 0.159 ND 0.100 ND 0.127 1.308 ** 

0.088 0.173 0.420 0.249 ** 22.45 0.284 0.367 * 

0.080 0.164 0.258 0.100 18.34 0.535 0.335 * 

0.105 0.234 0.240 0.090 20.79 0.730 0.550 ** 

0.095 0.229 0.304 0.073 21.88 0.304 0.103 

Oregon City, OR 1969 ND ND ND 0.180 0.331 0.510 ND ND ND 0.150 ND(45) 1970 ND ND ND 0.349 * 

1971 0.050 0.025 ND 0.299 * 

1972 0.059 0.022 ND 0.098 1973 0.025 ** 0.025 ND 0.126 

1974 ND ND ND ND 

1980 0.070 0.014 0.913 0.186 

1997 0.108 0.022 1.080 0.118 

0.440 ** 0.882 ** ND ND ND 0.604 ND 

0.367 * 0.744 * ND 0.050 ND 0.250 ND 

0.180 0.304 0.104 0.100 ND 0.447 ND 

0.248 0.449 0.067 0.050 ND 0.255 ND 

ND ND ND ND ND 0.274 ND 

0.160 0.262 0.214 * 0.140 * 22.54 0.177 0.917 ** 

0.115 0.268 0.108 0.043 18.89 0.250 0.015 

BassRiggins, ID 1971 0.025 ** 0.025 ND 0.360 0.794 ** 1.254 ND 0.050 ND 0.140 ND(43) 1972 0.025 ** 0.025 ND

1973 0.050 0.025 ND

1974 ND ND ND

1986 0.015 ** 0.006 ** 1.182

1997 0.127 0.058 1.007

Lewiston, ID 1969 

0.210 0.772 ** 0.861 0.680 0.050 ND 0.360 ND 

0.220 0.346 ** 0.656 0.830 0.050 ND 0.140 ND 

ND ND ND ND ND ND 0.050 ND 

0.248 0.386 0.730 0.606 0.170 * 12.97 0.060 0.075 * 

0.443 1.297 1.542 0.838 0.051 17.26 0.200 0.015 

(42) 

ND ND ND 0.150 1.102 0.844 ND ND ND 0.300 ND

1970 ND ND ND 0.210 

1971 0.060 0.025 ND 0.280 1978 0.050 0.010 0.380 0.190 1997 0.135 0.027 0.707 0.172 

0.579 0.752 ND ND ND 0.330 ND 

0.703 1.021 ND 0.050 ND 0.610 ** ND 

0.322 0.558 0.440 0.100 15.41 0.280 0.350 0.759 0.668 0.330 0.054 17.01 0.110 0.184 

Granger, WA 1969 ND ND ND 0.140 0.343 0.551 ND ND ND 0.940 ND(44) 1970 ND ND ND 0.270

1973 0.025 ** 0.025 ND 0.180

1974 ND ND ND ND

0.425 0.864 ND ND ND 1.660 ND 

0.233 0.514 0.100 ** 0.050 ND 0.770 ND 

ND ND ND ND ND 1.400 ND 

Environmental Contaminants and their Effects on Fish 
39 

Table 17. Historical trends of chemical contaminants in fish collected from NCBP stations in the Columbia River Basin. Least-squares mean concentrations (all in μg/g ww unless 

otherwise noted) of arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), length-adjusted Hg (HgL; μg/g/m ww), weight-adjusted Hg (HgW; μg/g/kg ww), selenium (Se), lead (Pb), zinc (Zn), p,p’-DDE, and PCB. Values within each group of taxon-station means followed asterisks differ significantly (*0.01<P0.05; **P0.01, Fisher’s protected LSD) from 1997 means. Also 

shown are ANOVA F-values, degrees-of-freedom (df), and significance levels. ND, no data/not measured. Stations are listed upstream to downstream within each taxon grouping.— Continued

Station and Year Contaminant 

Species As Cd Cu Hg HgW HgL Se Pb Zn DDE PCBs 

1997 0.138 0.028 0.605 0.188 0.340 0.578 0.375 0.055 15.28 0.817 0.223 

Oregon City, 1976 0.250 0.050 ND 0.130 0.573 0.556 ND 0.120 * ND 0.060 0.650 ** OR (45) 1997 0.123 0.025 0.584 0.251 0.457 0.766 0.123 0.049 15.98 0.186 0.020 Northern pikeminnowRiggins, ID 1970 ND ND ND 1.700 ** 3.748 ** 5.109 ** ND ND ND 0.740 ** ND(43) 1971 0.071 0.025 ND 0.710

1972 0.070 0.025 ND 0.180 * 

1978 0.160 0.010 * 0.640 0.2201980 0.050 0.020 0.760 0.2601997 0.122 0.036 0.759 0.521

1.844 * 2.240 ND 0.050 ND 0.312 * ND 

1.323 0.762 0.270 * 0.050 ND 0.220 ND 

0.346 0.574 0.340 0.100 20.51 0.520 * 0.900 ** 

5.732 ** 1.551 0.580 0.100 22.12 0.020 * 0.150 

0.831 1.350 0.484 0.049 20.78 0.093 0.048 

Granger, WA 1972 0.100 0.050 ND 0.640 2.822 * 2.333 0.400 0.050 ND 2.700 ND(44) 1997 0.125 0.025 1.035 0.480 0.798 1.162 0.317 0.050 16.05 0.800 0.170 ANOVA-F -- 5.45 12.08 4.44 10.61 11.45 10.90 10.11 9.26 31.49 7.19 9.05 

df -- 156,93 156,93 80,56 186,100 186,100 186,100 123,70 156,93 80,56 209,112 93,64 

Results and Discussion 
0.4 

0.6 

1 

1.5 

2 

1.5 

40 Environmental Contaminants and their Effects on Fish 

0.8 Hg 

Bass 

HgL 

117 504 98 41 43 42 96 503 97 44 46 502 506 45 505 501 

Snake R. 

Common Carp 

Sucker 

Pikeminnow 

Walleye 

Trout 

Upper Columbia R. Mid-Columbia R. Lower Columbia R. 

HgW 

10 

1 

8 

Pb 

Cd 

117 504 98 41 43 42 96 503 97 44 46 502 506 45 505 501 

Snake R. 

Common Carp 

Bass 

Sucker 

Pikeminnow 

Walleye 

Trout 

Upper Columbia R. Mid-Columbia R. Lower Columbia R. 

6 

μg/g μg/g

μg/g/kg μg/g/m μg/g 

4 

2 0.2 

0 

0 0.8 

0.6 

0.4 

0.5 0.2 

0 0 

Station 

Figure 5. Concentrations (μg/g ww) of lead (Pb) and cadmium (Cd) 

by station and taxon in whole body fish composite samples collected in the Columbia River Basin in 1997. Censored values are 

plotted as one half the LOD. Stations are ordered from upstream 

to downstream and are grouped by sub-basin. See Table 3 for 

0.5 station descriptions. 

stations (Table 14). Concentrations ranged from 0.10-9.3 μg/g 

ww with the maximum concentrations measured in female 

largescale sucker from Station 504. Samples from Stations 98, 0 

503, and 504 had concentrations >0.3 μg/g ww, and Station 

504 had the greatest geometric mean (1.25 μg/g ww) (Table Station 

15; Fig. 5); all other station geometric means were <0.24 μg/g 

ww. Concentrations in bass, northern pikeminnow, and walleye samples were <LOD. 

Concentrations of Pb differed spatially in carp and largescale sucker but not in bass and northern pikeminnow (Table 

16). Concentrations of Pb in carp were significantly greater at 

Station 503 than other stations (Table 16; Fig. 5). Concentrations of Pb in largescale sucker were significantly greater at 

Stations 43, 98, 504, and 506 than at Stations 117 and 501. 

Concentrations of Pb in largescale sucker at Stations 98 and 

504 were the greatest and were significantly different from one 

another and all other stations (Table 16; Fig. 5). 

Concentrations of Pb changed significantly at several stations in collections from 1971-1997 based on historical NCBP 

Figure 4. Concentrations (μg/g ww) of mercury (Hg) by station 

and taxon in whole body fish composite samples collected in the 

Columbia River Basin in 1997. Unadjusted (Hg), length-adjusted 

(HgL), and weight-adjusted (HgW) concentrations are shown. 

Censored values are plotted as one half the LOD. Stations are 

ordered from upstream to downstream and are grouped by subbasin. See text for computations and Table 3 for station descriptions 

Lead 

Concentrations of Pb in fish from the CRB were >LOD 

(0.09-0.14 μg/g ww) in 15 of 64 samples (23%) from eight 
41 

data (Table 17). Concentrations of Pb in carp at Stations 97 

and 44, largescale sucker at Stations 117, 98, 43, 46, and 45, 

and bass at Stations 43 and 45 differed significantly among 

years (Table 17). In general, a decline in concentrations of Pb 

in the CRB seen in the 1980s continued (Schmitt and others, 1999b); however, Station 98 had elevated concentrations 

(>0.35 μg/g ww) in 1980-1986 and 1997. Upstream from 

Station 98, largescale sucker from Station 504 had concentrations of Pb three to five times greater than in fish from any 

other station. Station 504 is 31-33 km downstream from a 

smelting complex located in British Columbia, which historically discharged slag and slurry effluent containing elemental 

contaminants into the CRB (Bortelson and others, 1994). 

Schmitt and others (2002a) reported liver concentrations of Pb 

of 1.34 μg/g ww in largescale sucker collected from Station 

504 in 1992. Serdar and others (1994) measured concentrations ranging from 3.0-12.0 μg/g ww in largescale sucker 

collected near Station 504. Other studies have documented 

high concentrations of Pb in bottom feeding fish collected near 

Pb smelters (Schmitt and others, 1993). Concentrations in the 

northern hog sucker (Hypentelium nigricans) and black redhorse (Moxostoma duduesnii) of 4.57 μg/g ww and 11.22 μg/g 

ww, respectively, collected near Pb smelters in Missouri are 

comparable to concentrations in largescale sucker from Station 

504 in 1997. The USEPA determined whole body concentrations for Pb in smallmouth bass and largescale sucker to range 

from 0.01-0.14 μg/g ww and 0.027-1.10 μg/g ww, respectively, 

in the CRB from 1996-1998 (USEPA, 2002b). Walsh and others (1977) also found similar concentrations of Pb in largescale sucker, smallmouth bass, and northern pikeminnow from 

the LCR. Whole body composite concentrations of Pb ranged 

from 0.01-0.69 μg/g ww in carp and 0.01-0.49 μg/g ww in 

bass in the MRB (Schmitt and others, 2002b). Another BEST 

project in the RGB also reported concentrations of Pb in carp 

(0.07-0.43 μg/g ww) and bass (0.03-0.83 μg/g ww) (Schmitt 

and others, 2004). 

The effects threshold of Pb in fish is ≥0.4 μg/g ww based 

on whole body concentrations (Holcombe and others, 1976; 

as reviewed in Jarvinen and Ankley, 1999). Holcombe and 

others (1976) determined that whole body concentrations of 

Pb were associated with reduced hatch ability (0.4 μg/g ww) 

and reduced growth (4.0-8.8 μg/g ww) in third generation 

brook trout at various life stages. Effects on heme synthesis 

have been associated with carcass concentrations of Pb >1.0 

μg/g ww and varying indirectly with Zn burden (Schmitt and 

others, 1993). Concentrations in largescale sucker from Stations 98 and 504 exceeded this value and the lowest thresholds of Holcombe and others (1976) but all concentrations in 

largescale sucker from the CRB were <0.34 μg/g ww in 1997. 

Most CRB fish did not approach these values although Pb 

appears to be a potential problem, at least in catostomids, at 

Stations 98 and 504. 

Results and Discussion 

Cadmium 

Concentrations of Cd in fish from the CRB were >LOD 

(0.043-0.063 μg/g ww) in 27 samples (42%) from 12 stations 

(Table 14). Eleven composite samples yielded concentrations 

>0.2 μg/g ww (Fig. 5) with the maximum concentration (0.51 

μg/g ww) measured in female carp from Station 503. The 

greatest station geometric mean was calculated for Station 

503 (0.12 μg/g ww) (Table 15). Carp and largescale sucker 

consistently had greater concentrations of Cd at most stations compared to other species collected. Similar patterns 

were reported the MRB (Schmitt and others, 2002b) and RGB 

(Schmitt and others, 2004) where carp had concentrations 

greater than predator species collected concomitantly. 

Spatial differences in concentrations of Cd were significant in carp, largescale sucker, and northern pikeminnow 

but not in bass (Table 16). Concentrations were significantly 

greater in carp at Stations 96, 97, 501, 502, and 503 than at 

Stations 41, 44, and 45 (Table 16; Fig. 5). Concentrations of 

Cd in largescale sucker were significantly greater at Stations 

46, 98, 504 than at Station 505; Stations 98 and 504 were also 

significantly greater than Station 46 (Table 16; Fig. 5). Concentrations of Cd in northern pikeminnow were significantly 

greater at Station 503 than at Stations 44 and 501 (Table 16; 

Fig. 5). 

Concentrations of Cd in fish from the CRB changed 

significantly at several stations from 1971-1997 based on historical NCBP data (Table 17). Concentrations in carp at Stations 42, 96, 97, and 44, largescale sucker at Stations 117, 98, 

43, and 46, and bass and northern pikeminnow at Station 43 

differed significantly among years (Table 17). Increasing or 

decreasing temporal trends were not clearly evident at any station except carp from Station 97 (Table 17). Composites from 

NCBP collections (1980-1986) had relatively low concentrations of Cd (<0.1 μg/g ww), with the exception of largescale 

sucker samples from Station 98 (Schmitt and others, 1999b). 

Serdar and others (1994) measured whole body concentrations 

ranging from 0.35-0.48 μg/g ww in largescale sucker collected 

near Station 504. The USEPA determined whole body concentrations for Cd in smallmouth bass and largescale sucker 

to range from 0.005-0.019 μg/g ww and 0.013-0.25 μg/g ww, 

respectively, in the CRB from 1996-1998 (USEPA, 2002b). A 

1994 study of the UCR reported concentrations of Cd in fillets 

of smallmouth bass, walleye, and rainbow trout to be <0.03 

μg/g ww (Munn and others, 1995), which are less than whole 

body concentrations measured in that region in 1997. Previous BEST projects from the MRB and RGB measured Cd in 

bass and carp. MRB concentrations ranged from 0.03-0.51 

μg/g ww in carp and 0.02-0.21 in bass μg/g ww (Schmitt and 

others, 2002b) while RGB concentrations were 0.02-0.12 

μg/g ww in carp and were <LOD in bass (Schmitt and others, 

2004). 

Birds and mammals are comparatively resistant to Cd; 

dietary toxicity thresholds were >100 μg/g in the studies 

reviewed by Eisler (1985). Nevertheless, Eisler (1985) suggested that a Cd concentration of 2 μg/g in fish is evidence of 
42 Environmental Contaminants and their Effects on Fish 

μg/g μg/g μg/g μg/g

200 

150 

100 

50 

0 

5 

4 

3 

2 

1 

0 

5 

4 

3 

2 

1 

0 

0.8 

0.6 

0.4 

0.2 

0 

Zn 

Cu 

Cr 

117 504 98 41 43 42 96 503 97 44 46 502 506 45 505 501 

Ni 

Common Carp 

Bass 

Sucker 

Pikeminnow 

Walleye 

Trout 

Upper Columbia R. Snake R. Mid-Columbia R. Lower Columbia R. 

Station 

Figure 6. Concentrations (μg/g ww) of zinc (Zn), copper (Cu), 

chromium (Cr), and nickel (Ni) by station and taxon in whole body 

fish composite samples collected in the Columbia River Basin in 

1997. Censored values are plotted as one half the LOD. Stations 

are ordered from upstream to downstream and are grouped by 

sub-basin. See Table 3 for station descriptions. 

contamination, that 5 μg/g is potentially life-threatening to the 

fish, and that 13-15 μg/g is a threat to higher trophic levels. 

A review by Jarvinen and Ankley (1999) included several 

laboratory studies in which whole body concentrations of Cd 

in freshwater fish ranging from 0.12-15.6 μg/g ww resulted 

in reduced survival and/or growth, and concentrations of 2-8 

μg/g ww caused decreased spawning and number of embryos 

produced in freshwater fish. Concentrations of Cd were well 

less than these benchmarks even though some 1997 concentrations exceeded historical NCBP concentrations. 

Zinc 

Concentrations of Zn in fish from the CRB ranged from 

11.6-105.6 μg/g ww, with the maximum measured in female 

carp from Station 45 (Table 14; Fig. 6). All carp samples had 

concentrations >54 μg/g ww while all other species samples 

were <51 μg/g ww. All geometric station means were similar 

(Table 15). Concentrations of Zn differed spatially in largescale sucker and bass but not in carp or northern pikeminnow 

(Table 16). Concentrations in largescale sucker were significantly greater at Stations 98 and 504 than other stations, 

similar to patterns in concentrations of Pb in largescale sucker 

(Table 16; Fig. 6). Concentrations in bass were significantly 

greater at Station 503 than at Station 43 (Table 16; Fig. 6). 

Concentrations of Zn changed significantly at Station 98 

in largescale sucker in collections from 1978-1997 based on 

historical NCBP data (Table 17). Concentrations of Zn from 

samples collected in 1978-1986 ranged from 13-33 μg/g ww 

with the exception of two carp samples (75 and 82 μg/g ww) 

from Station 97 (Schmitt and others, 1999b); carp from the 

same station in 1997 had concentrations ranging from 72-105 

μg/g ww. Historically, largescale sucker concentrations (13.3-

28.7 μg/g ww) were less than 1997 concentrations (17.7-50.9 

μg/g ww). The USEPA determined whole body concentrations 

of Zn in smallmouth bass and largescale sucker to range from 

15-18 μg/g ww and 16-38 μg/g ww, respectively, in the CRB 

from 1996-1998 (USEPA, 2002b). Serdar and others (1994) 

measured concentrations of Zn ranging from 23.1-84.5 μg/g 

ww in largescale sucker collected near Station 504. 

Concentrations of Zn >100 μg/g ww in whole carp have 

been reported from many locations throughout the Midwest 

(Schmitt, 2002a; Schmitt and others, 1999a). Sun and Jeng 

(1998) also reported concentrations of Zn >100 μg/g ww in 

carp. Common carp partition much of the Zn in their digestive 

tissue and, in general, have much greater concentrations than 

other species examined (Sun and Jeng, 1998). The growth and 

survival of American flagfish (Jordanella floridae), a cyprinid, 

exposed over a life-cycle (larvae-to-adult) were affected at 

concentrations of 40-64 μg/g ww (Spehar, 1976) as cited by 

Jarvinen and Ankley (1999). This is well within the range of 

concentrations normally encountered in carp but lower than 

levels typical for other fishes in the CRB (Schmitt and Brumbaugh, 1990; Schmitt and others, 1999b). Only concentrations 
43 

in carp and largescale sucker exceeded these threshold values 

in the CRB, so it is unlikely that either fish or higher trophic 

level organisms are adversely affected by Zn (Eisler, 1993). 

Copper 

Copper was detected in all samples ranging from 0.34-

3.92 μg/g ww, with the maximum concentration measured in 

male carp from Station 96 (Table 14). Comparatively high 

concentrations (>1.5 μg/g ww) were measured in carp at Stations 44, 96, 97, 502, and 503, northern pikeminnow at Station 

503, and largescale sucker at Stations 504 and 506 (Fig. 6). 

Stations 503 and 504 had geometric mean values >1.5 μg/g 

ww (1.68 and 1.71 μg/g ww, respectively) (Table 15). 

Concentrations of Cu were statistically different among 

stations in carp, largescale sucker, and northern pikeminnow 

but not in bass (Table 16). Concentrations of Cu in carp were 

significantly greater at Station 96 than at Stations 41 and 42; 

Stations 502 and 503 also had concentrations significantly 

greater than Station 42 (Table 16; Fig. 6). Concentrations of 

Cu in largescale sucker were significantly greater at Station 

504 than at Stations 43, 46, and 117 (Table 16; Fig. 6). Concentrations in northern pikeminnow were significantly greater 

at Station 503 than at Station 43 (Table 16; Fig. 6). 

In general, concentrations of Cu in fish collected in 1997 

were similar to historical NCBP concentrations (Schmitt and 

others, 1999b). Concentrations of Cu in largescale sucker 

changed significantly at Station 117 in collections from 1978­

1997 (Table 17). Largescale sucker collected from Stations 

41, 44, and 117 had concentrations >3.0 μg/g ww in 1980­

1986. Serdar and others (1994) measured concentrations of 

Cu ranging from 1.2-10.4 μg/g ww in largescale sucker collected near Station 504 in 1992-1993. Largescale sucker were 

only collected from Station 117 in this study, and concentrations of Cu had decreased to 0.84-0.96 μg/g ww. The USEPA 

determined whole body concentrations for Cu in smallmouth 

bass and largescale sucker to range from 0.50-0.56 μg/g ww 

and 0.80-5.6 μg/g ww, respectively, in the CRB from 1996­

1998 (USEPA, 2002b). Concentrations of Cu were reported 

in whole body composite samples of carp and bass in previous 

BEST projects. Concentrations of Cu were 0.47-2.68 μg/g ww 

in carp and 0.35-0.72 μg/g ww in bass in the MRB (Schmitt 

and others, 2002b). Similar concentrations were measured in 

carp (0.56-1.8 μg/g ww) and bass (0.36-0.95 μg/g ww) in the 

RGB (Schmitt and others, 2004). 

The ecological relevance of the concentrations of Cu 

in fish from the CRB is not known. Of the studies reviewed 

by Jarvinen and Ankley (1999), only the work of Stouthort 

and others (1996) was relevant; these authors determined that 

concentrations of 11.1-11.7 μg/g ww were associated with 

reduced survival of carp larvae, and concentrations of 42 μg/g 

ww reduced egg survival. However, no tissue-based criteria 

for Cu are available for the protection of avian and mammalian 

wildlife (Eisler, 1997). 

Results and Discussion 

Chromium and Nickel 

Chromium was detected in all samples (0.3-11.2 μg/g 

ww), with the maximum concentration measured in male largescale sucker from Station 506 (Table 14; Fig. 6). Geometric 

station means were <1.9 μg/g ww, with the exception of Station 506 (6.76 μg/g ww) (Table 15). The USEPA determined 

whole body concentrations of Cr in smallmouth bass and largescale sucker to range from 0.11-0.23 μg/g ww and 0.13-0.60 

μg/g ww, respectively, collected in the CRB from 1996-1998 

(USEPA, 2002b). Eisler (1986) suggested that concentrations 

of Cr >4 μg/g dw (approximately 1 μg/g ww) in the tissues and 

organs of fish and wildlife indicate environmental contamination; however, the significance of such a value is unclear. 

Most 1997 samples and station means had concentrations 

>1.0 μg/g ww (Fig. 6; Table 15). Concentrations of Cr were 

not determined by the NCBP (Schmitt and others, 1999b). 

Although Cr was measured as part of the 1995 MRB BEST 

project, concentrations were not reported (Schmitt and others, 2002b). Concentrations of Cr in whole body composite 

samples ranged from 0.38-71.8 μg/g ww in carp and 0.71-70.1 

μg/g ww in bass in the RGB (Schmitt and others, 2004). A 

recent review of the literature (Jarvinen and Ankley, 1999) 

found no studies linking whole body concentrations of Cr to 

survival or growth effects in freshwater fishes. 

Concentrations of Ni were >LOD (0.22-0.33 μg/g ww) in 

24 of 64 samples (38%) from 13 stations (Table 14). Concentrations ranged from 0.23-1.18 μg/g ww, with the maximum 

occurring female largescale sucker from Station 506 (Table 14; 

Fig. 6). Geometric station means were <0.31 μg/g ww, with 

the exception of samples from Stations 46 (0.61 μg/g ww) and 

506 (0.97 μg/g ww) (Table 15). Concentrations of Ni were 

not determined by the NCBP (Schmitt and others, 1999b). 

Although Ni was measured as part of the 1995 MRB BEST 

project, concentrations were not reported (Schmitt and others, 

2002b). The USEPA determined whole body concentrations 

of Ni in smallmouth bass and largescale sucker to range from 

0.054-0.096 μg/g ww and 0.055-11.0 μg/g ww, respectively, 

collected in the CRB from 1996-1998 (USEPA, 2002b). The 

BEST program measured greater concentrations of Ni in carp 

(0.18-4.21 μg/g ww) and bass (0.23-3.29 μg/g ww) in the RGB 

compared to the CRB (Schmitt and others, 2004). Like Cu, 

studies are also lacking for linkages of whole body concentrations to effects for Ni (Jarvinen and Ankley, 1999), and tissue-based criteria for the protection of fishes and piscivorous 

wildlife are not available for this metal. 

Data for additional elements (Al, B, Ba, Be, Fe, Mg, 

Mn, Mo, Sr, V), along with all other data from this study, are 

available at <http://www.cerc.usgs.gov/data/best/search/>. Of 

these, B, Be, and Mo were <LOD in all samples. 
44 

Table 18. Occurrence (percentages of samples and stations with concentrations >0.01 μg/g ww for individual compounds and >0.03 μg/g ww for toxaphene and total 

PCBs) of organochlorine chemical residues in composite samples of whole fish in the Columbia River Basin in 1997. The maximum concentrations and associated sample information (station, species, and gender) from this study are also given. ND, not detected. a Sum of cis- and trans-chlordanes and nonachlors; oxychlordane; and 

heptachlor epoxide, with censored values represented as one half the LOD. b1,1a,2,2,3,3a,4,5,5,5a,5b,6-Dodecachloro-octahydro-1,3,4-metheno-1Hcyclobuta(cd)pentalene. c Perchlorobenzene. d Sum of -, , , and -hexachlorocyclohexane, with censored values represented as one half the LOD. 

Samples Stations Maximum 1997 concentration Analyte(s) (% of 64) (% of 16) μg/g Station Gender Species 

p,p’-DDT 20 38 p,p’-DDD (TDE) 67 75 

p,p’-DDE 94 94 Total p,p’-homologs 100 100 

o,p’-DDT 8 19 o,p’-DDD (TDE) 3 6 o,p’-DDE 3 6 

Dieldrin 20 44 Endrin 3 6 

cis-Chlordane 6 19 trans-Chlordane 3 6 

cis-Nonachlor 3 6 

trans-Nonachlor 23 50 Oxychlordane 3 6 Heptachlor epoxide 3 6 Total chlordane-related residues a 100 100 

Toxaphene 3 6 

0.310 Granger, WA (44) M/F Largemouth bass 

0.200 Vernita Bridge, WA (503) M Carp 

1.200 Granger, WA (44) M Smallmouth bass 

1.390 Granger, WA (44) M Smallmouth bass 

0.043 Vernita Bridge, WA (503) M Carp 

0.010 Vancouver, WA (506) M/F Largescale sucker 

0.010 Vancouver, WA (506) M/F Largescale sucker 

0.029 Lewiston, ID (42) M Carp 

0.010 Vancouver, WA (506) M/F Largescale sucker 

0.020 Portland, OR (505) F Largemouth bass 

0.010 Vancouver, WA (506) M/F Largescale sucker 

0.010 Vancouver, WA (506) M/F Largescale suck 

0.100 Lewiston, ID (42) M Carp 

0.010 Vancouver, WA (506) M/F Largescale sucker 

0.010 Vancouver, WA (506) M/F Largescale sucker 

0.125 Lewiston, ID (42) M Carp 

0.050 Vancouver, WA (506) M/F Largescale sucker 

b Mirex 3 6 

Hexachlorobenzene (HCB) c 6 13 

Total PCBs 67 81 

0.010 Vancouver, WA (506) M/F Largescale sucker 

0.020 Ice Harbor Dam, WA (96) F Carp 

1.300 Vernita Bridge, WA (503) F Northern pikeminnow 

d Hexachlorocylohexane (HCH) 6 13 0.020 Ice Harbor Dam, WA (96) F Carp 

Environmental Contaminants and their Effects on Fish 
Results and Discussion 45 

μg/g wet-weight 

1 

0.9 

0.8 

0.7 

0.6 

0.5 

0.4 

0.3 

0.2 

0.1 

0 

98 41 43 96 503 

DDT 

DDE 

DDD 

117 504 42 97 44 46 502 506 45 505 501 

Upper Columbia R. Snake R. Mid-Columbia R. Lower Columbia R. 

Station 

Figure 7. Weighted geometric mean concentrations (μg/g ww) of p,p’-DDT, DDE, and DDD by station in whole body fish composite 

samples collected in the Columbia River Basin in 1997. Censored values are represented by one half the LOD in the computation of 

means and totals but are not shown in the figure. Stations are ordered from upstream to downstream and are grouped by sub-basin. 

See Table 3 for station descriptions. 

Organochlorine Chemicals 

DDT and its primary metabolites 

Concentrations of DDT, both p,p and o,p congeners, 

were measured in fish in the CRB. Use of DDT was banned 

in the U.S. in 1972, but concentrations of this persistent 

organochlorine insecticide and its metabolites remain present 

in the environment from historical use and as a consequence 

of atmospheric transport. Elevated concentrations of DDT 

residues are most common in cotton-growing areas of the U.S. 

and near former sites of production and formulation, although 

atmospheric transport from sites where DDT is still used can 

also deposit these chemicals (Schmitt and others, 2002b). Our 

study found the parent compound, p,p’-DDT, exceeded LOD 

(>0.01 μg/g ww) in 13 of 64 samples (20%) from six stations 

(Table 18) and accounted for 3.1% of the total detected DDT 

(p,p’-homologs) in fish sampled in 1997. The greatest concentrations (individual samples and geometric station means) 

of p,p’-DDT and total DDT were from Station 44 (Table 18; 

Figure 7). Bass from Station 44 had concentrations of p,p’-

DDT ranging from 0.06-0.31 μg/g ww. Stations 46 and 505 

also had samples that were >LOD, and samples from Stations 

96, 503, and 506 had trace amounts of p,p’-DDT present in the 

fish (0.01-0.02 μg/g ww). 

The major metabolite of p,p’-DDT, p,p’-DDE, was 

detected in 60 of 64 fish composites (Table 18) and accounted 

for 87% of the total detected DDT (Fig. 7). Stations 117, 504, 

and 98 in the UCR had concentrations <LOD (0.01 μg/g ww) 

in fish samples (Fig. 8). Composite samples with concentrations >0.5 μg/g ww included carp from Station 42 (0.56 and 

0.59 μg/g ww), carp, bass, and northern pikeminnow from 

Station 44 (0.50-1.2 μg/g ww), carp from Station 96 (0.70-

0.92 μg/g ww), carp and largescale sucker from Station 501 

(0.51–0.68 μg/g ww), and carp and bass from Station 503 

(0.51–1.1 μg/g ww). Geometric station means were greatest at 

Stations 44, 503, 501, and 96 (Table 19). 
46 Environmental Contaminants and their Effects on Fish 

1.5 

1 

0.5 

0 

0.06 

0.04 

0.02 

0 

0.2 

0.15 

0.1 

0.05 

0 0.04 

0.03 

0.02 

0.01 

0 

-DDE 

Bass 

117 504 98 41 43 42 96 503 97 44 46 502 506 45 505 501 

p,p' Common Carp 

Sucker 

Pikeminnow 

Walleye 

Trout 

Toxaphene 

Total Chlordanes 

Dieldrin 

Upper Columbia R. Snake R. Mid-Columbia R. Lower Columbia R. 

μg/g μg/g μg/g μg/g 

Station 

Figure 8. Concentrations (μg/g ww) of p,p’-DDE, toxaphene, total 

chlordanes, and dieldrin by station and taxon in whole body fish 

composite samples collected in the Columbia River Basin in 1997. 

Total chlordanes are the sum of cis- and trans-chlordanes and 

nonachlors, heptachlor epoxide, and oxychlordane. Censored 

values are plotted as one half the LOD. Stations are ordered from 

upstream to downstream and are grouped by sub-basin. See 

Table 3 for station descriptions. 

Among-station differences in concentrations of p,p’-DDE 

were significant in carp, largescale sucker, bass, and northern 

pikeminnow (Table 16). Concentrations of p,p’-DDE were 

significantly greater in carp at Stations 42, 96, and 503 than at 

Stations 41, 45, and 97; Station 44 samples also had concentrations of p,p’-DDE significantly greater than Station 45 

(Table 16; Fig. 8). Concentrations of p,p’-DDE in largescale 

sucker were significantly greater at Station 501 than at Stations 98, 117, 504, 505, and 506; Stations 43, 45, 46, 505, and 

506 also had concentrations of p,p’-DDE significantly greater 

than Stations 98, 117, and 504 (Table 16; Fig. 8). Concentrations of p,p’-DDE in bass were significantly lower at Station 

117 that at all other stations. Station 44 also had concentrations of p,p’-DDE in bass that were significantly greater than 

Stations 42, 45, 97, and 505 (Table 16; Fig. 8). Concentrations of p,p’-DDE in northern pikeminnow were significantly 

greater at Station 44 than at Station 43 (Table 16; Fig. 8). 

Concentrations of p,p’-DDE changed significantly at 

several stations from 1969-1997 based on historical NCBP 

data (Table 17). Concentrations of p,p’-DDE in carp at Stations 42, 97, 44, and 45, largescale sucker at Stations 117, 98, 

43, 46, and 45, and bass and northern pikeminnow at Station 

43 differed significantly among years (Table 17). Decreasing temporal trends were evident in samples at Stations 117 

(largescale sucker), 97 (carp), and 43 (northern pikeminnow). 

Increasing temporal trends were not clearly evident at any 

station. Johnson and others (1988) reported on the persistence 

of DDT in the Yakima River drainage (near Station 44) and 

concluded that irrigation diversions increased concentrations 

of DDT compounds in the water. Other studies found lower 

concentrations of p,p’-DDE in fish from the LCR compared to 

our findings (Curtis and others, 1993; ODEQ, 1994; USEPA, 

1992). Previous BEST projects measured p,p’-DDE in carp 

and bass. Concentrations of p,p’-DDE ranged from 0.01-8.3 

μg/g ww in carp and 0.01-0.53 μg/g ww in bass in the MRB 

(Schmitt and others, 2002b), and concentrations in the RGB 

were slightly less than the MRB in carp (0.01-0.67 μg/g ww) 

and bass (0.01-0.40 μg/g ww) (Schmitt and others, 2004). 

Concentrations of p,p’-DDE in carp and bass in the MRB 

and RGB were generally less than CRB concentrations with 

the exception of MRB stations in western Mississippi which 

consistently had carp concentrations >2.0 μg/g ww (Schmitt 

and others, 2002). Carp and bass from the lower SR and MCR 

consistently exceeded the 95th percentile (0.33 μg/g ww) for 

concentrations of p,p’-DDE measured in fish collected in a 

nationwide survey in 1992-1995 (Wong and others, 2000). 

Concentrations of p,p’-DDD are due to p,p’-DDT breakdown and use as an insecticide. This compound accounted 

for 10.2% of the total detected DDT (≥0.01 μg/g ww) and 

was detected in 43 of 64 composite samples. Relatively high 

concentrations (0.1–0.2 μg/g ww) were measured in fish composite samples from Stations 96 and 503. Geometric station 

means did not exceed 0.06 μg/g ww with the exception of fish 

samples at Station 503 (0.11 μg/g ww) (Table 19). Wong and 

others (2000) detected p,p’-DDD (≤1.2 μg/g ww) in 42% of 

fish collected in a nationwide survey in 1992-1995. 
Continued

47 

Table 19. Unweighted geometric mean, minimum, and maximum concentrations (μg/g ww unless otherwise indicated) of organochlorine chemical contaminant in fish 

collected from the Columbia River Basin in 1997. Censored values were replaced by one-half of the LOD value for the computation of station means, but only if at least one value exceeded detection limits. Total DDT are the total of p,p’-DDT homologs. Total chlordane is the sum of cis-chlordane, trans-chlordane, cis-nonachlor, transnonachlor, heptachlor epoxide and oxychlordane; heptachlor epoxide and oxychlordane were not detected in any samples but were included in total chlordane at 0.005 μg/g 

(one half the LOD). The maximum geometric station mean is shown in bold for each contaminant. Stations are grouped by sub-basin and are listed upstream to downstream.— 

p,p’- p,p’- p,p’- Total cis- trans- cis- trans- Total Toxa- TCDD-EQ Station Dieldrin Total PCBs DDD DDE DDT DDT a Chlordane Chlordane Nonachlor Nonachlor Chlordane phene (pg/g) 

Upper Columbia River (UCR)Creston, MT Mean <0.01 <0.01 <0.01 0.02 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 0.40 (117) Min. <0.01 <0.01 <0.01 0.02 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 0.34 

(n = 4) Max. <0.01 <0.01 <0.01 0.02 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 0.67 

Northport, WA Mean <0.01 0.02 <0.01 0.03 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.11 1.50 (504) Min. <0.01 0.01 <0.01 0.02 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 1.00 

(n = 4) Max. <0.01 0.03 <0.01 0.04 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.35 5.00 

Grand Coulee, Mean <0.01 0.01 <0.01 0.02 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 1.19 WA (98) Min. <0.01 0.01 <0.01 0.02 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 1.00 

(n = 3) Max. <0.01 0.02 <0.01 0.03 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 2.00 

Snake River (SR) Hagerman, ID Mean 0.02 0.23 <0.01 0.26 <0.01 <0.01 <0.01 0.01 0.03 <0.01 <0.03 <0.03 1.81 (41) Min. 0.01 0.15 <0.01 0.17 <0.01 <0.01 <0.01 0.01 0.03 <0.01 <0.03 <0.03 0.67 (n = 4) Max. 0.03 0.36 <0.01 0.39 <0.01 <0.01 <0.01 0.01 0.04 <0.01 <0.03 <0.03 4.00 

Riggins, ID (43) Mean <0.01 0.15 <0.01 0.16 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.02 0.39 (n = 5) Min. <0.01 0.09 <0.01 0.10 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 0.10 

Max. <0.01 0.25 <0.01 0.26 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.05 2.00 

Lewiston, ID Mean 0.02 0.25 <0.01 0.28 <0.01 <0.01 <0.01 0.01 0.04 0.01 <0.03 0.16 1.41 (42) Min. <0.01 0.10 <0.01 0.11 <0.01 <0.01 <0.01 0.01 0.03 <0.01 <0.03 0.05 1.00 

(n = 4) Max. 0.09 0.59 <0.01 0.69 <0.01 <0.01 <0.01 0.10 0.13 0.03 <0.03 0.64 2.00 

Ice Harbor Mean 0.06 0.43 0.01 0.50 0.01 <0.01 <0.01 0.01 0.04 0.01 <0.03 0.08 8.20

Dam, WA (96) Min. 0.02 0.23 <0.01 0.26 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 3.00 

(n = 4) Max. 0.19 0.92 0.01 1.12 0.02 <0.01 <0.01 0.02 0.06 0.02 <0.03 0.26 43.00 

Middle Columbia River (MCR)Vernita Bridge, Mean 0.11 0.48 0.01 0.60 <0.01 <0.01 <0.01 <0.01 0.03 0.01 <0.03 0.49 6.29

WA (503) Min. 0.07 0.28 <0.01 0.35 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.20 6.00 

(n = 4) Max. 0.20 1.10 0.02 1.31 <0.01 <0.01 <0.01 <0.01 0.03 0.01 <0.03 1.30 8.00 

Results and Discussion 
48 Table 19. Unweighted geometric mean, minimum, and maximum concentrations (μg/g ww unless otherwise indicated) of organochlorine chemical contaminant in fish 

collected from the Columbia River Basin in 1997. Censored values were replaced by one-half of the LOD value for the computation of station means, but only if at least one value exceeded detection limits. Total DDT are the total of p,p’-DDT homologs. Total chlordane is the sum of cis-chlordane, trans-chlordane, cis-nonachlor, transnonachlor, heptachlor epoxide and oxychlordane; heptachlor epoxide and oxychlordane were not detected in any samples but were included in total chlordane at 0.005 μg/g 

(one half the LOD). The maximum geometric station mean is shown in bold for each contaminant. Stations are grouped by sub-basin and are listed upstream to downstream.—Continued 

p,p’- p,p’- p,p’- Total cis- trans- cis- trans- Total Toxa- TCDD-EQ Station Dieldrin Total PCBs DDD DDE DDT DDT a Chlordane Chlordane Nonachlor Nonachlor Chlordane phene (pg/g)

Pasco, WA Mean 0.04 0.23 <0.01 0.27 <0.01 <0.01 <0.01 <0.01 0.03 0.01 <0.03 0.03 4.82 (97) Min. 0.02 0.17 <0.01 0.20 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 3.00 

(n = 4) Max. 0.07 0.35 <0.01 0.43 <0.01 <0.01 <0.01 <0.01 0.03 0.01 <0.03 0.06 6.00 

Granger, WA Mean 0.05 0.73 0.04 0.90 <0.01 <0.01 <0.01 <0.01 0.03 0.01 <0.03 0.15 1.09 (44) Min. 0.04 0.46 <0.01 0.51 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.04 1.00 

(n = 6) Max. 0.08 1.20 0.31 1.39 <0.01 <0.01 <0.01 <0.01 0.03 0.02 <0.03 0.62 2.00 

Lower Columbia River (LCR) Cascade Locks, Mean 0.05 0.30 0.02 0.38 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.10 4.47 OR (46) Min. 0.04 0.25 0.01 0.30 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.08 2.00 

(n = 2) Max. 0.08 0.37 0.03 0.48 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.13 10.00 

Warrendale, OR Mean 0.04 0.27 <0.01 0.32 <0.01 <0.01 <0.01 0.01 0.03 <0.01 <0.03 0.33 5.03 (502) Min. 0.03 0.18 <0.01 0.22 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.12 3.00 

(n = 4) Max. 0.07 0.40 <0.01 0.47 <0.01 <0.01 <0.01 0.02 0.04 <0.01 <0.03 0.68 8.00 

Vancouver, WA Mean 0.03 0.13 0.02 0.18 0.01 0.01 0.01 0.01 0.06 0.01 0.05 0.29 2.65 (506) Min. 0.03 0.13 0.01 0.18 0.01 0.01 0.01 0.01 0.06 0.01 0.05 0.11 1.00 

(n = 2) Max. 0.03 0.14 0.02 0.19 0.01 0.01 0.01 0.01 0.06 0.01 0.05 0.75 7.00 

Oregan City, Mean 0.01 0.14 <0.01 0.16 <0.01 <0.01 <0.01 0.01 0.03 <0.01 <0.03 0.04 2.20 OR (45) Min. <0.01 0.03 <0.01 0.04 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 <0.03 1.00 

(n = 6) Max. 0.03 0.46 <0.01 0.48 <0.01 <0.01 <0.01 0.01 0.04 <0.01 <0.03 0.36 9.00 

Portland, OR Mean 0.04 0.12 0.01 0.17 0.01 <0.01 <0.01 0.01 0.04 0.01 <0.03 0.31 3.81 (505) Min. 0.01 0.05 <0.01 0.07 <0.01 <0.01 <0.01 <0.01 0.03 <0.01 <0.03 0.19 2.00 

(n = 4) Max. 0.08 0.42 0.07 0.51 0.02 <0.01 <0.01 0.03 0.07 0.02 <0.03 0.52 7.00 

Beaver Army Mean 0.03 0.42 <0.01 0.47 <0.01 <0.01 <0.01 0.01 0.03 <0.01 <0.03 0.24 2.11 Terminal, OR Min. 0.01 0.22 <0.01 0.26 <0.01 <0.01 <0.01 0.01 0.03 <0.01 <0.03 0.06 0.34 

(501) Max. 0.07 0.68 <0.01 0.70 <0.01 <0.01 <0.01 0.01 0.04 <0.01 <0.03 0.38 8.00 (n = 4)

Environmental Contaminants and their Effects on Fish 
Results and Discussion 49 

μg/g wet-weight 

0.07 

0.06 

0.05 

0.04 

0.03 

0.02 

0.01 

0 

117 504 98 41 43 42 96 503 97 44 46 502 506 45 505 501 

Heptachlor epoxide 

Oxychlordane 

cis-Chlordane 

trans-Chlordane 

cis-Nonachlor 

trans-Nonachlor 

Upper Columbia R. Snake R. Mid-Columbia R. Lower Columbia R. 

Station 

Figure 9. Weighted geometric mean concentrations (μg/g ww) of chlordane-related compounds (cis- and trans-chlordanes and nonachlors, heptachlor epoxide, and oxychlordane) by station in whole body fish composite samples collected in the Columbia River Basin 

in 1997. Censored values are represented by one half the LOD in the computation of means and totals but are not shown in the figure. 

Stations are ordered from upstream to downstream and are grouped by sub-basin. See Table 3 for station descriptions. 

Geometric means for total DDT (p,p’-homologs) were 

highest at Stations 44, 503, 501, and 96 (Fig. 7). Stations 98, 

117, and 504 were the only stations to have concentrations 

of total DDT <0.15 μg/g ww in fish samples; however, all 

stations had samples with concentrations <1 μg/g ww. Historically, low concentrations of total DDT have been recorded in 

fish at Stations 43, 98, and 117 (Schmitt and others, 1999b). 

Station 45 had comparatively low concentrations of all three 

homologs in 1986 fish samples. Station 44 has had fish samples with higher concentrations in the past due to use of DDT 

in agricultural areas along the Yakima watershed (Schmitt and 

others, 1990). Relatively high concentrations of total DDT 

were still present as reported in this other studies (Munn and 

Gruber, 1997). Mean p,p’-DDT homolog concentrations from 

Stations 44 and 96 exceeded 1986 NCBP concentrations in 

1997 (Schmitt and others, 1999a). The USEPA determined 

whole body concentrations for p,p’-DDT and p,p’-DDE for a 

variety of fish species including smallmouth bass and largescale sucker from the CRB in 1996-1998 (USEPA, 2002b). 

Concentrations in smallmouth bass ranged from 0.97-1.7 μg/g 

ww for p,p’-DDE and 0.044-0.08 μg/g ww for p,p’-DDT; 

concentrations in largescale sucker ranged from 0.028-1.30 

μg/g ww for p,p’-DDE and <0.001-0.18 μg/g ww for p,p’-

DDT. Concentrations of total DDT in carp (0.02-0.70 μg/g 

ww) and bass (0.02-0.43 μg/g ww) in the RGB were similar to 

those in the CRB (Schmitt and others, 2004). 

Multiple studies have suggested criteria to protect wildlife from DDT toxicity. Concentrations of total DDT in fish 

>0.15 μg/g ww are potentially harmful to the brown pelican 

(Pelicanus occidentalis), a sensitive avian species (Anderson 

and others, 1975), and wildlife criteria as low as 0.20 μg/g ww 

has been suggested by Newell and others (1987). According 

to studies reviewed by Blus (1996), concentrations of 1-3 μg/g 

ww are potentially hazardous to most piscivorous birds. A 

review by Jarvinen and Ankley (1999) associated toxic effects 

to fish with whole body concentrations as low as 0.5 μg/g ww. 

Reduced survival has been reported with whole body concentrations of total DDT in fry or fingerlings in cutthroat trout 

(Oncorhynchus clarki) (0.57 μg/g ww) (Cuerrier and others, 

1967), rainbow trout (1.14-1.42 μg/g ww) (Cuerrier and others, 1967; Hopkins and others, 1969), brook trout (0.46-5.03 

μg/g ww) (Cuerrier and others, 1967; Macek, 1968), lake trout 

(S. namaycush) (2.93 μg/g ww) (Burdick and others, 1964), 

coho salmon (O. kisutch) (1.09-2.76 μg/g ww) (Johnson and 
50 Environmental Contaminants and their Effects on Fish 

Pecor, 1969), and chinook salmon (O. tshawytscha) (11.6-

21.7 μg/g ww) (Buhler and others, 1969). Reduced survival 

has been reported with whole body concentrations of total 

DDT in juvenile and adult green sunfish (Lepomis cyanellus) 

and pumpkinseed (L. gibbosus) (24 μg/g ww) (Hamelink and 

others, 1971), fathead minnows (57-209 μg/g ww) (Jarvinen 

and others, 1976; 1977), and goldfish (Carassius auratus) 

(200-400 μg/g ww) (Rhead and Perkins, 1984). No station 

had a geometric mean concentration of total DDT >1.0 μg/g 

ww (Fig. 7). However, individual samples from Stations 44, 

96, and 503 exceeded 1.0 μg/g ww. All stations except those 

from the UCR (Stations 117, 504, and 98) had individual fish 

sample concentrations of total DDT >0.15 μg/g ww. 

Technical DDT contains o,p’-DDT as an impurity, and 

residues of this compound and its metabolites also remain 

widespread (Schmitt and others, 1985; 1999b; 2002b). Concentrations of these compounds were not detected in bass or 

carp in the RGB in 1997 (Schmitt and others, 2004). Comparatively low concentrations of o,p’-DDT (0.01–0.043 μg/g 

ww) were detected in samples from Stations 503, 505, and 

506 in the CRB. Largescale sucker from Station 506 had trace 

concentrations of o,p’-DDE and o,p’-DDD (0.01 μg/g ww 

for each). Although the o,p’ homologs have historically been 

considered relatively benign, o,p’-DDD is weakly estrogenic 

(Ackerman and others, 2002; Guillette and others, 1996; Toppari and others, 1996), as are many other pesticides and their 

metabolites (Tyler and others, 1998). Wong and others (2000) 

reported o,p’-DDT (≤0.14 μg/g ww) was detected in only 6% 

of fish collected in a nationwide survey in 1992-1995. The 

total risk to fish and wildlife represented by concentrations of 

o,p’-DDT is unknown. 

Cyclodiene pesticides: 

Chlordane and heptachlor 

Chlordane is a mixture of cyclopentadiene-derived 

compounds that was widely used as a soil insecticide. Concentrations of these compounds are typically greatest in fish 

from corn-growing regions, urban areas in the “termite belt” 

or southeastern U.S., and near production and formulation 

facilities (Schmitt, 2002b; Schmitt and others, 1999b). Six 

chlordane-related components and metabolites were measured 

in the 1997 samples: cis-chlordane, trans-chlordane, cis-nonachlor, trans-nonachlor, oxychlordane, and heptachlor epoxide 

(Table 18). Heptachlor epoxide is a metabolite of heptachlor, 

which is a minor constituent of chlordane and was also used 

historically as an insecticide. Environmental concentrations of 

heptachlor epoxide result from both sources. Oxychlordane is 

a metabolite of cis-chlordane. Concentrations of trans-chlordane, cis-nonachlor, oxychlordane and heptachlor epoxide 

were <LOD (0.01 μg/g ww) in all samples with the exception 

of largescale sucker samples from Station 506 (Table 18). Cischlordane exceeded LOD (0.01 μg/g ww) in samples from Stations 505 (0.02 μg/g ww) and 96 (0.016 μg/g ww) and at LOD 

in both largescale sucker composites from Station 506 (Table 

18; Fig. 9). Trans-nonachlor, the most frequently detected 

chlordane constituent, was detected (0.01 μg/g ww) in 15 of 64 

samples (23%) from eight stations (Table 18). Concentrations 

ranged from 0.01-0.10 μg/g ww, with the maximum concentration measured in male carp from Station 42 (Fig. 8). Male 

and female largemouth bass samples from Station 505 had 

concentrations of 0.03 μg/g ww, and samples from Stations 41, 

45, 96, 501, 502, and 506 had trace concentrations (0.01-0.02 

μg/g ww) (Fig. 8). 

NCBP concentrations from samples collected 1980-1986 

for all of these compounds except trans-nonachlor were either 

not detected or detected at trace concentrations (0.005 or 0.01 

μg/g ww) (Schmitt and others, 1999b). Concentrations of 

trans-nonachlor were 0.03 μg/g ww in largescale sucker and 

northern pikeminnow samples from Stations 45 and 46 in 

1980; all other samples had trace concentrations. Wong and 

others (2000) reported concentrations of chlordane compounds 

in fish from a nationwide survey. Trans-nonachlor (≤0.12 μg/g 

ww) was detected in 34%, cis-chlordane (≤0.15 μg/g ww) in 

24%, cis-nonachlor (≤0.05 μg/g ww) in 19%, trans-chlordane 

(≤0.06 μg/g ww) in 17%, oxychlordane (≤0.03 μg/g ww) in 

12%, and heptachlor epoxide (≤0.02 μg/g ww) in 6% of the 

fish samples. 

Concentrations of total chlordanes (sum of six compounds) in 1997 ranged from 0.03-0.13 μg/g ww, with the 

maximum concentrations measured in male carp from Station 

42; other samples did not exceed 0.072 μg/g ww (Fig. 8). All 

geometric station means for total chlordane were ≤0.06 μg/g 

ww (Table 19). Munn and Gruber (1997) reported similar 

concentrations of chlordane in largescale sucker and carp from 

the mid-CRB. A USEPA study (USEPA, 1992) also reported 

similar concentrations in the LCR. Chlordane residues >0.1 

μg/g ww are of concern for the health of predatory fish and 

fish-eating birds (Eisler, 1990). Total chlordane was measured 

in the MRB in carp (0.05 to >0.5 μg/g ww) and bass (0.05 to 

<0.4 μg/g ww) (Schmitt and others, 2002b). Concentrations 

of total chlordane in the RGB in carp (0.03-0.05 μg/g ww) and 

bass (0.03-0.06 μg/g ww) were similar to those measured in 

the CRB (Schmitt and others, 2004). 

Dieldrin 

Most environmental dieldrin is present due to the breakdown of aldrin, which has not been used since 1974. Concentrations were ≥LOD (0.01 μg/g ww) in the CRB were found in 

20% of the samples from seven sites (Table 18). Concentrations were greatest for male and female carp from Station 42, 

0.029 and 0.026 μg/g ww, respectively (Fig. 8). Concentrations ranged from 0.014-0.023 μg/g ww for male smallmouth 

bass, male carp, and female smallmouth bass from Station 44. 

Trace concentrations (0.01–0.02 μg/g ww) were detected in 

samples from Stations 96, 97, 503, 505, and 506. All geometric station means were <0.01 μg/g ww (Table 19). 
51 

Historically, concentrations of dieldrin in fish samples 

were ≤LOD (0.01 μg/g ww) at Stations 41, 43, 44, 98 and 

117 (Schmitt and others, 1999b). In contrast, concentrations in samples at Stations 42, 45, 96 and 97 were ≥0.2 μg/g 

ww. Relatively high measured concentrations were measured 

in fish samples from Station 44 in 1997 but not from 1980­

1986. Species differences could account for the differences in 

accumulation rather than greater inputs to the site. Munn and 

Gruber (1997) reported similar concentrations in largescale 

sucker and carp from the mid-CRB. Several other studies 

found similar concentrations in the LCR (Curtis and others, 

1993; ODEQ, 1994; USEPA, 1992). Previous BEST projects 

from the MRB (Schmitt and others, 2002) and RGB (Schmitt 

and others, 2004) reported trace concentrations of dieldrin in 

most carp (0.01-0.25 μg/g ww) and bass (0.01-0.08 μg/g ww). 

Dieldrin was detected at concentrations of ≤0.26 μg/g ww in 

29% of fish sampled in a nationwide survey from 1992-1995 

(Wong and others, 2000). 

These concentrations probably do not represent a significant threat to either fish or piscivores (Jarvinen and Ankley, 

1999; Peakall, 1996). As cited in Jarvinen and Ankley (1999), 

whole body concentrations in juvenile rainbow trout of 0.36-

2.13 μg/g ww were determined to have no effect on survival 

or growth of juvenile rainbow trout, but concentrations of 5.65 

μg/g ww reduced survival (Macek and others, 1970; Shubat 

and Curtis, 1986). 

Endrin 

Endrin, one of the most toxic organochlorine pesticides 

to fish (Johnson and Finley, 1980), was used on comparatively 

few crops in the past. Concentrations of endrin were ≤LOD 

(0.01 μg/g ww) in all samples from all locations (Table 18). 

Only trace levels of endrin (≥0.01 μg/g ww) have been found 

at the NCBP sites since 1980 (Schmitt and others, 1999b). 

Other studies reported similar results in the LCR (Curtis and 

others, 1993; ODEQ, 1994; USEPA, 1992). Previous BEST 

projects from the MRB (Schmitt and others, 2002b) and RGB 

(Schmitt and others, 2004) also reported non-detected or trace 

concentrations (0.01 μg/g ww) of endrin in carp and bass. 

Endrin was detected at concentrations of ≤0.02 μg/g ww in 2% 

of fish sampled in a nationwide survey from 1992-1995 (Wong 

and others, 2000). 

Other Organochlorine Compounds 

Mirex 

Mirex was used as an insecticide to combat red imported 

fire ants (Solenopsis wagneri) in the southern U.S. Elsewhere, 

mirex was used as a flame retardant and as a polymerizing 

agent (Kaiser, 1987). Consistent with previous NCBP findings 

(Schmitt and others, 1999b), concentrations of mirex were 

Results and Discussion 

≤LOD (0.01 μg/g ww) in the 1997 CRB samples (Table 18). 

Other studies reported similar concentrations in the LCR (Curtis and others, 1993; ODEQ, 1994; USEPA, 1992) and other 

U.S. river basins (Schmitt and others, 2002b; 2004). Mirex 

was not detected in a 1992-1995 U.S. fish survey (Wong and 

others, 2000). 

Toxaphene 

Toxaphene was the most heavily used insecticide in the 

U.S. following the ban on DDT (Schmitt and Winger, 1980). 

Use of toxaphene in the U.S. peaked in the late 1970s and the 

pesticide was subsequently banned. Concentrations of toxaphene in NCBP fish samples peaked in the mid-1970s, reflecting use (Schmitt and others, 1999b). Although toxaphene was 

used mostly on cotton, this pesticide has been atmospherically transported to remote locations and residues have been 

detected in fish from the Arctic and the Great Lakes (Muir and 

others, 1999; Schmitt and others, 1999b). In 1997, toxaphene 

was detected (>0.03 μg/g ww) in only two largescale sucker 

samples from Station 506 in the CRB (Fig. 8; Table 18). 

Fish from Stations 42, 44, 46, 96, and 98 had concentrations of toxaphene ranging from 0.2-1.0 μg/g ww from 

1980-1986 based on historical NCBP data (Schmitt and others, 1999b). Other studies also reported low concentrations 

in the LCR (Curtis and others, 1993; ODEQ, 1994; USEPA, 

1992) and in the RGB (Schmitt and others, 2004). However, 

concentrations of toxaphene in carp in the MRB (0.05-8.3 μg/g 

ww) were greater than in the CRB, with concentrations >2.0 

μg/g ww in the lower MRB cotton producing region (Schmitt 

and others, 2004). Toxaphene was detected at concentrations 

of ≤0.21 μg/g ww in 0.4% of fish sampled in a 1992-1995 

nationwide survey (Wong and others, 2000). 

Acute and chronic effects of toxaphene on freshwater fish 

have been reported at whole body concentrations ≥0.4 μg/g 

ww (Eisler and Jacknow, 1985; Jarvinen and Ankley, 1999). 

Only male and female largescale sucker samples from Station 

506 exceeded this threshold. Jarvinen and Ankley (1999) 

reviewed multiple laboratory studies on acute and chronic 

effects of toxaphene. Among these were several by Mayer and 

others (1975; 1978). These authors reported that adult brook 

trout containing whole body concentrations of 0.4 μg/g ww 

produced eggs with reduced viability, and lake trout (Salvelinus namaycush) and white sucker containing 0.035-0.203 μg/g 

ww also produced eggs with reduced viability (Mayer and 

others, 1975). Survival and growth of freshwater fish (several 

species) at various life stages were reduced at concentrations 

>0.90 μg/g ww (Mayer and others, 1975; 1978). It should be 

noted that the complete composition of the toxaphene components present cannot be determined based on the low-resolution analytical methods used on the 1997 samples (Ribick and 

others, 1982), and the composition and toxicity of weathered 

toxaphene can vary greatly (Bidleman and others, 1993; 

Gooch and Matsumura, 1987; Harder and others, 1983; Ribick 

and others, 1982). 
52 Environmental Contaminants and their Effects on Fish 

Hexachlorocyclohexanes (HCH) 

Four HCH isomers (α-, β-, δ-, γ-HCH) were measured in 

the 1997 CRB samples. Although a mixture of isomers was 

historically used on cotton and other crops in the U.S., only γHCH (lindane) is still used in North America for some agricultural and domestic applications. HCH isomers are relatively 

short-lived. All samples from the CRB had concentrations 

≤LOD (0.01 μg/g ww) (Table 18). Concentrations of α- and 

γ- HCH were ≤LOD (0.01 μg/g ww) in samples collected from 

NCBP sites from 1980-1986 (Schmitt and others, 1999b) and 

in other U.S. basins sampled by the BEST program (Schmitt 

and others, 2002b; 2004). Wong and others (2000) rarely 

detected (<5% frequency) HCH isomers in a nationwide fish 

survey from 1992-1995. 

Hexachlorobenzene (HCB) 

HCB was produced for use as a fungicide and was a 

by-product of the production of other chlorinated hydrocarbons. This compound is less toxic to fish than many other 

persistent organochlorines (Schmitt and others, 1999b), but 

contains toxic impurities. Concentrations of HCB were ≤LOD 

(0.01 μg/g ww) in all samples with the exception of Station 

96. Concentrations in male and female carp from Station 96 

were 0.01-0.02 μg/g ww, respectively. Traces of HCB were 

measured in samples from Station 96 in 1986 (Schmitt and 

others, 1999b). In general, historical concentrations of HCB 

from the CRB sites were ≤LOD (0.01 μg/g ww). Previous 

BEST projects also measured concentrations of HCB ≤0.01 

μg/g ww in carp and bass (Schmitt and others, 2002b; 2004). 

HCB was detected at concentrations of ≤0.03 μg/g ww in 7% 

of fish sampled in a nationwide survey from 1992-1995 (Wong 

and others, 2000). 

Total PCBs, H4IIE-Derived Dioxin Equivalents, 

and Ethoxyresorufin O-Deethylase (EROD) 

Activity 

Total PCBs 

Total PCBs were >LOD (0.03 μg/g ww) in 43 of 64 

samples (67%) from 13 stations (Table 18). Concentrations 

ranged from 0.03-1.3 μg/g ww, with the maximum concentrations measured in female northern pikeminnow from Station 

503 (Table 18; Fig. 10). Other samples with concentrations 

≥0.5 μg/g ww included male smallmouth bass from Station 42 

(0.64 μg/g ww), female smallmouth bass from Station 44 (0.62 

μg/g ww), female northern pikeminnow from Station 502 

(0.68 μg/g ww), male largemouth bass from Station 505 (0.52 

μg/g ww), and female largescale sucker from Station 506 (0.75 

pg/g μg/g 

1.5 

1 

0.5 

0 

40 

12 

10 

8 

6 

4 

2 

0 

Bass 

Sucker 

98 41 43 42 96 503 97 44 46 45 Snake R. 

50 

Total PCBs Common Carp 

Pikeminnow 

Walleye 

Trout 

117 504 502 506 505 501 

Upper Columbia R. Mid-Columbia R. Lower Columbia R. 

Figure 10. Concentrations of total PCBs (μg/g ww) and H4IIE bioassay-derived TCDD-EQ (pg/g) by station and taxon in whole body 

fish composite samples collected in the Columbia River Basin in 

1997. Stations are ordered from upstream to downstream and are 

grouped by sub-basin. See Table 3 for station descriptions. 

μg/g ww). Geometric station means were greatest (≥0.30 μg/g 

ww) in samples at Stations 502, 503, and 505 (Table 18). 

Like p,p’-DDE, among-station differences for concentrations of PCBs were significant in carp, largescale sucker, bass, 

and northern pikeminnow (Table 16). Concentrations in carp 

were significantly greater at Stations 45, 96, 501, 502 and 503 

than at Stations 41, 42, 44, and 97 (Table 16; Fig. 10). Concentrations of PCBs in largescale sucker were significantly 

greater at Stations 43, 46, 501, 504, 505, and 506 than at 

Stations 98 and 117; Stations 46 and 505 also had concentrations of PCBs significantly greater than Station 45 (Table 16; 

Fig. 10). Concentrations of PCBs in bass were significantly 

greater at Stations 42, 44, 502, 503, and 505 that Stations 41, 

43, 45, 96, 97, and 117 (Table 16; Fig. 10). Concentrations in 

northern pikeminnow were significantly lower at Station 43 

than at all other stations; fish samples at Station 503 also had 
53 

concentrations of PCBs that were significantly greater than 

Station 44 (Table 16; Fig. 10). 

Concentrations of PCBs changed significantly at several stations from 1976-1997 (Table 17). Concentrations of 

PCBs in 1997 were significantly lower than historical NCBP 

concentrations in carp at Stations 97 and 44, largescale sucker 

at Stations 117, 98, 43, 46, and 45, bass at Stations 43 and 45, 

and northern pikeminnow at Station 43 (Table 17). 

Similar concentrations of PCBs (0.03-1.3 μg/g ww) were 

found in other studies in the SR (Clark and Maret, 1998) and 

CRB (Foster and others, 2001; Tetra Tech Inc., 1996). The 

USEPA determined whole body concentrations for Aroclor® 

mixtures (1254 and 1260) in smallmouth bass and largescale 

sucker to range from 0.046-0.19 μg/g ww and <0.014-0.10 

μg/g ww, respectively, in the CRB in 1996-1998 (USEPA, 

2002b). Fish composites analyzed for Aroclor® mixtures 

(1248, 1254, 1260) from 1980-1986 generally contained trace 

residues (≤0.2 μg/g ww) (Schmitt and others, 1999b). In 1980, 

northern pikeminnow and largescale sucker samples collected 

at Stations 45, 46, and 117 contained concentrations between 

0.3-0.7 μg/g ww (Schmitt and others, 1999b). Concentrations 

of PCBs ranged from 0.05-3.3 μg/g ww in carp and 0.05-2.0 

μg/g ww in bass in the MRB (Schmitt and others, 2002b) and 

were not detected in the RGB (Schmitt and others, 2004). 

Total PCBs were detected in 80% of fish sampled in a nationwide survey from 1992-1995, with concentrations ranging 

from <0.05-72 μg/g ww (Wong and others, 2000). 

The New York State Department of Environmental Conservation (NYSDEC) wildlife guideline for total PCBs in fish 

is 0.11 μg/g ww (Newell and others, 1987), a concentration 

exceeded by at least one fish sample from all stations except 

Stations 43 and 97 (Fig. 10). However, the toxicity of individual PCB congeners ranges over several orders of magnitude 

(Ahlborg and others, 1994; van den Berg and others, 1998) 

and varies with the endpoint being considered (Hansen, 1998). 

Decreased survival of fry at approximately 5 μg/g ww of 

Aroclor® 1254 has been reported in several laboratory studies (Hansen and others, 1973; Schimmel and others, 1974 as 

cited in Monosson, 1999). Niimi (1996) as cited in Beyer and 

others (1996) determined that fish tissue concentrations of 100 

μg/g ww can affect reproduction in females or be lethal, and 

concentrations of 50 μg/g ww can reduce growth and survival 

in offspring. However, these concentrations may be lower in 

more sensitive fish species (Niimi, 1996). Mink fed Great 

Lakes fish or fish products with concentrations of PCBs of 

0.48 μg/g ww had inferior reproductive performance and offspring survival (Hornshaw and others, 1983). Concentrations 

of PCBs in fish are decreasing compared to historical NCBP 

concentrations but exceed several criteria. Therefore, PCBs 

remain at levels of concern at some CRB stations. 

H4IIE Bioassay 

Twenty-one bass samples from eleven stations in the 

CRB were analyzed for dioxin-like activity. TCDD-EQs in 

Results and Discussion 

female bass (n=9) ranged from <1.33-7 pg/g, male bass (n=9) 

ranged from <0.68-7.0 pg/g, and a male and a female bass 

sample were <LOQ. Three intersex samples had TCDD-EQs 

ranging from 1–6 pg/g. Individual samples with relatively 

high total PCBs did not have the highest TCDD-EQ levels 

(Fig. 10). Overall, TCDD-EQs for bass were relatively low. 

The H4IIE bioassay was used to analyze seventeen carp 

samples from nine stations (Table 18; Fig. 10). The TCDDEQ in female carp (n=8) ranged from <LOD to 43 pg/g; 

whereas male carp (n=9) ranged from 1–9 pg/g. Concentraions of PCBs in carp samples did not exceed 0.5 μg/g ww 

total PCBs suggesting the value of 43 pg/g found in female 

carp at Station 96 may be caused by other compounds (for 

example, PCDDs and PCDFs). The other carp and two bass 

composite samples collected from Station 96 were ≤7 pg/g 

(Fig. 10). 

Seventeen largescale sucker samples from nine stations 

were analyzed for TCDD-EQs. TCDD-EQ in the female largescale sucker (n=9) ranged from <0.68–10 pg/g; one sample 

was <LOQ. TCDD-EQ in male largescale sucker (n=8) 

ranged from <0.35–2 pg/g; three samples were <LOQ. Only 

two largescale sucker samples (female samples from Station 

46 and 506) were >5 pg/g (Fig. 10). Female largescale sucker 

from Station 506 (7 pg/g) had total PCBs >0.5 μg/g ww. 

Similar to the bass samples from the CRB, largescale sucker 

samples had relatively low TCDD-EQs. TCDD-EQs were 

also relatively low (0-8 pg/g) for rainbow trout, walleye, and 

northern pikeminnow samples. 

Previous studies have examined TCDD-EQ levels in 

fish. The dietary threshold for toxicity of TCDD is 4.4 pg/g in 

mammals (Heaton and others, 1995; Tillitt and others, 1996) 

and 5 pg/g in avian wildlife (Nosek and others, 1992). Most 

of the TCDD-EQ levels in fish from the CRB are similar to 

those reported in fish from reference sites in previous studies 

(Giesy and others, 1995; Schmitt and others, 2002b; 2004; 

van den Heuvel and others, 1995) and from sites in the LCR 

(Bonn, 1997). TCDD-EQ values ≥60 pg/g were reported and 

levels ≥20 pg/g were widespread in fish samples from the 

MRB (Schmitt and others, 2002b). TCDD-EQ values were 

low in carp (<1-3 pg/g) and bass (<1-6 pg/g) in the RGB 

(Schmitt and others, 2004). CRB station means ranged from 

0.39-8.0 pg/g (Table 19). Five samples ranged from 8-10 pg/g. 

One TCDD-EQ value (43 pg/g) in female carp from Station 

96 was notably greater than all other samples and approached 

the threshold for toxic effects in fish (30 pg/g) (Schmitt and 

others, 2002b and references cited therein; Walker and others, 

1996; Whyte and others, 2004). 

Ethoxyresorufin O-Deethylase (EROD) Activity 

EROD activity varies among fish species, between 

genders, and reproductive stage (Schmitt and others, 2002b; 

Whyte and others, 2000). A significant ANOVA model for 

bass containing the factors station, gender, and developmental 

stage explained 49% of the total variance in EROD activity 
—Continued

-- 

-- 

-- 

-- 

--- --- 

--- --- 

--- --- 

-- 

-- 

54 Environmental Contaminants and their Effects on Fish 

Table 20. Results of preliminary analysis-of-variance investigating the effects of various factors on biomarker responses in carp, bass, 

and largescale sucker in the Columbia River Basin in 1997. Shown are degrees-of-freedom (df), F-values with levels of significance 

(*0.01<P0.05; **P0.01), and coefficients of determination (R2

). 

Variable, source, and Bass Carp Largescale sucker 

(transformation) df F R2 df F R2 df F R2 

EROD (log) 

Model 37 2.41** 0.49 25 7.28** 0.59 22 1.06 0.19 

Station 8 1.66 6 1.31 7 0.73 

Gender 1 4.51* 1 0.50 1 1.25 

Station*Gender 6 1.71 2 0.11 0 

Stage 1 0.53 1 3.02 1 0.11 

Stage*Station 8 0.87 6 2.46* 7 0.66 

Stage*Gender 1 4.21* 1 2.10 1 1.34 

Stage*Station*Gender 6 1.14 2 0.26 0 

Error 92 125 97 

Condition Factor 

Model 38 2.40** 0.50 27 1.37 0.23 28 4.25** 0.48 

Station 8 3.95** 7 0.35 9 3.44** 

Gender 1 4.46* 1 0.01 1 0.06 

 Station*Gender 6 2.61* 2 0.00 0 

Stage 1 2.40 1 0.00 1 0.41 

Stage*Station 8 3.45** 7 0.04 9 2.1* 

Stage*Gender 1 2.53 1 0.01 1 0.18 

Stage*Station*Gender 6 2.23* 2 0.00 0 

Error 93 127 128 

Splenosomatic Index 

Model 22 1.45 0.23 16 6.72** 0.43 15 7.64** 0.49 

Station 11 1.16 8 6.85** 8 12.02** 

Gender 1 0.05 1 30.1** 1 0.00 

Station*Gender 10 1.38 7 2.29* 6 1.91 

Error 107 140 120 

Hepatosomatic Index 

Model 22 3.66** 0.43 ND ND ND ND ND ND 

Station 11 4.17** ND ND ND ND 

Gender 1 1.33 ND ND ND ND 

Station*Gender 10 2.56** ND ND ND ND 

Error 108 ND ND 

HAI (rank) 

Model 38 3.76** 0.61 27 1.40 0.23 28 1.25 0.22 

Station 8 2.45* 7 0.48 9 0.58 

Gender 1 0.12 1 0.14 1 0.07 

 Station*Gender 6 0.22 2 3.12* 0 

Stage 1 1.38 1 3.29 1 0.93 

Stage*Station 8 0.75 7 0.66 9 0.89 

Stage*Gender 1 0.12 1 0.03 1 0.06 

Stage*Station*Gender 6 0.29 2 2.03 0 

Error 92 127 128 
-- 

-- 

Results and Discussion 55 

Table 20. Results of preliminary analysis-of-variance investigating the effects of various factors on biomarker responses in carp, bass, 

and largescale sucker in the Columbia River Basin in 1997. Shown are degrees-of-freedom (df), F-values with levels of significance 

(*0.01<P0.05; **P0.01), and coefficients of determination (R2

).—Continued 

Variable, source, and Bass Carp Largescale sucker 

(transformation) df F R2 df F R2 df F R2 

TISSOC 

Model 40 7.29** 0.60 33 5.36* 0.37 35 2.50** 0.44 

Station 10 1.95* 8 0.81 9 1.58 

Gender 1 3.46 1 0.25 1 2.43 

Station*Gender 8 2.00 7 1.00 7 1.22 

Age 1 12.05** 1 2.58 1 2.80 

Age*Station 10 2.47* 8 0.76 9 2.35* 

Age*Gender 1 4.89* 1 0.24 1 3.06 

Age*Station*Gender 8 2.34* 7 0.91 7 2.04 

Error 80 92 112 

MEANAREA 

Model 40 2.14** 0.52 33 1.24 0.31 35 2.53** 0.44 

Station 10 1.21 8 1.00 9 2.07* 

Gender 1 4.48* 1 0.04 1 0.32 

Station*Gender 8 1.84 7 1.26 7 2.65* 

Age 1 5.46* 1 2.75 1 2.49 

Age*Station 10 1.46 8 0.88 9 2.83** 

Age*Gender 1 5.11* 1 0.19 1 0.63 

Age*Station*Gender 8 2.19* 7 1.04 7 3.74** 

Error 80 92 112 

MAMM 

Model 40 2.16** 0.52 33 1.77* 0.39 35 1.12 0.26 

Station 10 1.33 8 0.57 9 0.84 

Gender 1 0.74 1 0.19 1 0.77 

Station*Gender 8 0.59 7 0.21 7 0.76 

Age 1 3.03 1 0.84 1 0.08 

Age*Station 10 1.51 8 0.54 9 0.74 

Age*Gender 1 0.40 1 0.56 1 0.56 

Age*Station*Gender 8 0.57 7 0.16 7 0.67 

Error 80 92 112 

Gonadosomatic Index 

Model 38 16.08** 0.87 27 12.95** 0.73 28 12.12** 0.73 

Station 8 0.77 7 2.41* 9 5.26** 

Gender 1 0.85 1 2.75 1 3.49 

Station*Gender 6 0.76 2 0.57 0 

Stage 1 16.74** 1 2.57 1 14.05**

 Stage*Station 8 1.79 7 1.81 9 10.19** 

Stage*Gender 1 14.07** 1 10.37** 1 0.64 

Stage*Station*Gender 6 1.86 2 1.71 0 

Error 92 127 127 
-- 

-- 

56 Environmental Contaminants and their Effects on Fish 

Table 20. Results of preliminary analysis-of-variance investigating the effects of various factors on biomarker responses in carp, bass, 

and largescale sucker in the Columbia River Basin in 1997. Shown are degrees-of-freedom (df), F-values with levels of significance 

(*0.01<P0.05; **P0.01), and coefficients of determination (R2

).—Continued 

Variable, source, and Bass Carp Largescale sucker 

(transformation) df F R2 df F R2 df F R2 

Vitellogenin (log) 

Model 37 13.44** 0.85 25 79.86** 0.94 22 55.68** 0.93 

Station 8 1.13 6 0.99 7 0.33 

Gender 1 0.00 1 6.49* 1 6.02* 

Station*Gender 6 1.44 2 1.33 0 

Stage 1 5.97* 1 9.32** 1 0.01 

Stage*Station 8 0.80 6 1.92 7 0.74 

Stage*Gender 1 18.78** 1 12.11** 1 0.15 

Stage*Station*Gender 6 1.26 2 1.53 0 

Error 87 125 97 

Atresia 

Model 34 1.33 0.54 20 2.36* 0.57 31 1.36 0.44 

Station 6 0.46 1 0.32 2 0.54 

Stage 1 0.10 1 0.24 1 1.38 

Stage*Station 6 0.27 1 0.34 2 0.68 

Age 1 1.66 1 0.30 1 2.26 

Age*Station 6 0.79 1 0.35 2 0.74 

Stage*Age 1 0.17 1 0.28 1 2.19 

Stage*Age*Station 6 0.43 1 0.39 2 0.77 

Error 38 36 53 

(log-transformed), with gender and a stage-gender interaction 

being significant (Table 20). The ANOVA model for carp was 

also significant and explained 59% of the total variance, and 

like bass, EROD activity did not differ significantly among 

stations after accounting for all other effects. In addition, the 

interaction of stage and gender was also significant in carp 

(Table 20). Gender and developmental stage of largescale 

sucker did not influence EROD activity (Table 20). However, analysis of the larger 1995 MRB BEST data set, which 

spanned a wider range of EROD values, also indicated that 

gender was a significant variable (Schmitt and others, 2002b). 

Therefore, EROD activity was tabulated and evaluated by 

gender. 

EROD in Bass 

Mean EROD activity in female bass was greatest (40.4 

pmol/min/mg) at Station 505 (n=5), ranging from 30.2-57.4 

pmol/min/mg (Fig. 11; Table 21). All other geometric station 

means for female bass were <21.8 pmol/min/mg. Most female 

bass with EROD levels >20 pmol/min/mg were identified as 

stage-1 fish, which supports the interaction determined by 

the ANOVA modeling (Table 20). Adams and others (1994) 

determined basal EROD activity for female bass to be 0-5 

pmol/min/mg, which is less than basal EROD activity (0-16 

pmol/min/mg) determined for female bass from the MRB 

(Schmitt and others, 2002b). Fish from Stations 42, 43, 44, 

45, 96, 97, 117, and 505 had EROD activity >16 pmol/min/ 

mg; however, only Stations 45, 117, and 505 had EROD values consistently >16 pmol/min/mg. 

EROD activities were similar in male and female bass. 

Mean EROD activity in male bass was greatest (68.3 pmol/ 

min/mg) at Station 505 (n=3), ranging from 47.6-99.4 pmol/ 

min/mg (Fig. 11; Table 21). All other geometric station means 

for male bass were <18.1 pmol/min/mg with the exceptions 

of Stations 45 (29.4 pmol/min/mg) and 117 (27.8 pmol/min/ 

mg). Unlike female bass in which stage-1 fish had the greatest EROD activity, most male bass with EROD activity >20 

pmol/min/mg were stage 2 and 3, which supports the interaction determined by ANOVA modeling (Table 20). 

Other studies have examined EROD activity in bass. 

Adams and others (1994) determined basal EROD activity for 

male bass to be 0-17 pmol/min/mg, which is slightly less than 

basal EROD activity (0-22 pmol/min/mg) determined for male 

bass from the MRB (Schmitt and others, 2002b). EROD activities in bass at RGB stations ranged from 21.3-108 pmol/min/ 

mg in females and 17.0-75.9 pmol/min/mg in males (Schmitt 

and others, 2004). Fish from Stations 42, 43, 44, 45, 97, 117, 

and 505 had EROD activity >22 pmol/min/mg; however, only 

Stations 45, 117, and 505 had EROD values consistently >22 

pmol/min/mg. Two bass in which no gonads were collected 
S

S

S

S

SS

S

S

S

S

S

SS

S

S

S

Results and Discussion 57 

1000 had EROD rates of 43.1 pmol/min/mg (Station 42) and 48.8 

pmol/min/mg (Station 45). 

100 

Bass-female 

Bass-male 

EROD in Carp 

10 Mean EROD activity in female carp was greatest (10.3 

pmol/min/mg) at Station 45, ranging from 6.54-22.9 pmol/ 

min/mg (Fig. 11; Table 21). All other geometric station means 1000 

for female carp were <3.17 pmol/min/mg. Schlenk and others 

(1996) determined basal EROD activity for carp from uncon­ 100 

taminated sites to be 0-5 pmol/min/mg, which is similar to 

basal EROD activity (0-4 pmol/min/mg) determined for carp 10 from the MRB (Schmitt and others, 2002b). Fish from Stations 41, 42, 45, 96, 502, and 503 had EROD activity greater 1 than these basal levels; however, only Station 45 had female 

carp with EROD values consistently exceeding basal EROD 

1000 

Carp-female 

Carp-male 

Largescale sucker-female 

Largescale sucker-male 

Upper 

Columbia R. Snake R. 

MidColumbia R. Lower 

Columbia R. 

Mean EROD activity in male carp was greatest (10.6 

10 pmol/min/mg) at Station 503, ranging from 3.88-212 pmol/ 

min/mg (Fig. 11; Table 21). Geometric means for male carp 

1 at the other stations ranged from 0.89 pmol/min/mg (Station 

97) to 8.76 pmol/min/mg (Station 96). Unlike the female carp, 

0.1 several stations had multiple individual EROD activities that 

100 levels from previous studies. 

pmol/min/mg 

exceeded basal EROD levels in previous studies (Schlenk and 1000 

others, 1996; Schmitt and others, 2002b), including fish from 

Stations 42, 45, 96, and 503 with measured EROD levels >10 

pmol/min/mg. 

Other studies have examined EROD activity in common carp. EROD activities in carp were <10 pmol/min/mg in 

females but were greater in males (many >20 pmol/min/mg) 

in the RGB (Schmitt and others, 2004). Several studies have 

100 

10 

1 

0.1 

reported juvenile carp in laboratory control groups to have 

EROD activities ranging from 7.1-25 pmol/min/mg (Kosmala 100 and others, 1998; Marionnet and others, 1997; 1998; Taysee 

and others, 1998). In studies examining adult carp, EROD 

activity in laboratory control groups ranged from 2.7-14.3 

10 

1 pmol/min/mg (Deér and others, 1996) and 41.9 pmol/min/mg 1000 (Solé and others, 2000). Machala and others (1997) dem100 onstrated that microsomal EROD activity in carp was a very 

sensitive and specific biomarker of the early effects of PAHs 10 

and PCBs. 

1 

0.1 

EROD in Largescale Sucker 0.01 

Mean EROD activity in female largescale sucker was 0.001 117 5049841434296 503974446 502 50645 505 501

greatest (30.7 pmol/min/mg) at Station 505, ranging from 

8.45-107 pmol/min/mg (Fig. 11; Table 21). All other geo- Station metric station means for female largescale sucker were <23.0 

Figure 11. Hepatic microsomal EROD activity (pmol/min/mg) by station in female and male bass (Micropterus sp.), carp, and largescale sucker collected in the Columbia River Basin in 1997. Shown 

for each group are points representing individual fish and the mean 

(red horizontal line), median (black horizontal line), interquartile 

range (box), and the 10th and 90th percentiles (whiskers). Stations 

are ordered from upstream to downstream and are grouped by 

sub-basin. See Table 3 for station descriptions. 

pmol/min/mg. Mean EROD activities in male largescale 

sucker were comparable to females with the greatest activity (30.5 pmol/min/mg) measured at Station 43. All other 

geometric station means for male largescale sucker were <19.7 

pmol/min/mg. 

Basal EROD levels for largescale sucker have not 

been reported previously; however, white sucker and long­
nued 

-- -- 

-- -- 

-- -- 

-- 

-- -- 

-- -- 

-- -- 

-- -- 

-- -- -- 

-- 

-- -- 

-- -- 

-- -- 

-- -- 

-- -- 

-- -- 

-- -- 

-- -- 

-- -- 

-- -- 

-- -- 

-- -- 

-- -- 

-- 

-- -- -- -- 

-- -- -- -- 

-- 

-- 

-- -- -- -- 

-- -- 

-- -- 

-- -- -- 

-- -- -- -- 

58 Environmental Contaminants and their Effects on Fish 

Table 21. Geometric mean and range of microsomal EROD activities (pmol/min/mg protein) in fish collected in the Columbia River 

Basin in 1997. Censored values were represented by one half the LOQ in the computation of geometric means. Fish in which gender 

was undetermined or no gonad was obtained are listed as juvenile. The maximum geometric station mean is shown in bold for each 

taxon. Stations are ordered upstream to downstream.—Conti 

Species and Station n 

Female 

Range Mean n 

Male 

Range Mean n 

Juvenile 

Range Mean 

Bass 

Upper Columbia River 

Creston, MT (117) 11 11.5-33.8 18.5 10 14.2-51.8 27.8 0 

Snake River 

Hagerman, ID (41) 9 3.89-15.79 8.52 7 4.32-15.9 7.75 0 

Riggins, ID (43) 3 5.68-233 21.8 4 4.82-34.0 16.4 0 

Lewiston, ID (42) 5 10.0-32.9 16.3 7 10.9-31.8 18.1 1 43.1 

Ice Harbor Dam, WA (96) 4 6.87-17.2 10.9 3 2.3-18.1 8.2 0 

Middle Columbia River 

Vernita Bridge, WA (503) 3 3.60-7.61 5.21 2 4.76-8.27 6.28 0 

Pasco, WA (97) 9 3.15-23.8 11.3 6 10.2-29.7 15.2 0 

Granger, WA (44) 9 4.3-33.9 10.9 6 0.18-36.7 6.9 0 

Lower Columbia River 

Warrendale, OR (502) 1 11.6 3 11.0-22.1 15.8 0 

Oregon City, OR (45) 15 2.65-42.2 12.5 5 10.1-82.8 29.4 1 48.8 

Portland, OR (505) 5 30.2-57.4 40.4 3 47.6-99.4 68.3 0 

Common Carp 

Snake River 

Hagerman, ID (41) 10 0.58-8.77 2.01 10 1.35-4.66 2.52 0 

Lewiston, ID (42) 5 0.18-6.66 2.11 12 0.18-11.5 3.31 0 

Ice Harbor Dam, WA (96) 10 0.88-5.72 2.44 11 2.35-24.4 8.76 0 

Middle Columbia River 

Vernita Bridge, WA (503) 10 1.45-8.24 3.01 11 3.88-212 10.6 0 

Pasco, WA (97) 11 0.05-1.43 0.27 9 0.06-4.32 0.89 0 

Granger, WA (44) 10 0.85-3.02 1.62 10 0.89-25.1 3.00 0 

Lower Columbia River 

Warrendale, OR (502) 10 1.64-10.8 3.17 10 3.60-51.7 6.82 0 

Oregon City, OR (45) 4 6.54-22.9 10.3 10 0.98-19.0 7.82 0 

Largescale Sucker 

Upper Columbia River 

Creston, MT (117) 4 5.27-151 16.2 6 0.60-20.0 9.36 0 

Northport, WA (504) 10 4.00-12.8 7.23 10 9.53-42.6 19.5 0 

Grand Coulee, WA (98) 10 9.07-67.8 22.0 10 6.00-59.8 19.7 0 

Snake River 

Riggins, ID (43) 11 8.43-33.5 15.7 9 5.39-86.5 30.5 0 

Lower Columbia River 

Cascade Locks, OR (46) 11 9.49-48.7 19.5 9 0.99-108 14.1 1 9.31 

Warrendale, OR (502) 3 3.50-60.7 23.0 0 0 

Oregon City, OR (45) 6 8.35-24.8 15.6 0 0 

Portland, OR (505) 11 8.45-107 30.7 10 0.04-107 13.2 2 28.2 

Longnose sucker 

Upper Columbia River 

Creston, MT (117) 10 2.36-11.0 5.05 1 18.0 2 4.12-6.57 5.20 

Grand Coulee, WA (98) 1 3.00 1 7.34 0 

Northern pikeminnow 

Snake River 

Riggins, ID (43) 9 0.18-4.33 1.31 5 0.18-7.79 2.22 0 

Middle Columbia RIver 

Vernita Bridge, WA (503) 8 2.10-102 10.7 2 2.07-26.1 7.4 0 

Granger, WA (44) 5 0.18-3.37 0.78 1 0.18 0 

Lower Columbia River 

Cascade Locks, OR (46) 2 3.11-48.1 12.2 0 0 
-- -- -- -- 

-- -- -- -- 

-- -- -- -- -- 

Results and Discussion 59 

Table 21. Geometric mean and range of microsomal EROD activities (pmol/min/mg protein) in fish collected in the Columbia River 

Basin in 1997. Censored values were represented by one half the LOQ in the computation of geometric means. Fish in which gender 

was undetermined or no gonad was obtained are listed as juvenile. The maximum geometric station mean is shown in bold for each 

taxon. Stations are ordered upstream to downstream.—Continued 

Species and Station n 

Female 

Range Mean n 

Male 

Range Mean n 

Juvenile 

Range Mean

 Warrendale, OR (502) 11 0.64-5.53 2.14 0 0 

Portland, OR (505) 2 1.59-2.44 1.97 0 0 

Rainbow trout 

Upper Columbia River 

Northport, WA (504) 10 1.19-25.2 9.18 2 6.85-12.0 9.05 8 4.94-41.5 15.1 

Walleye 

Upper Columbia River 

Grand Coulee, WA (98) 8 9.45-51.8 24.3 4 16.7-26.3 19.5 4 25.8-30.7 28.3 

Lower Columbia River 

Portland, OR (505) 1 4.83 0 0 

nose sucker have reported EROD levels ranging from 5-15 

pmol/min/mg (Whyte and others, 2000). Other studies have 

reported EROD activities to range from 8.5-10 pmol/min/mg 

in white sucker from reference or uncontaminated sites (Couillard and Hodson, 1996; Schrank and others, 1997). EROD 

activity in white sucker from a site contaminated by PCBs, 

PAHs, and heavy metals was determined to be 35.2 pmol/min/ 

mg (Schrank and others, 1997). Stations 43, 45, 46, 98, 117, 

502, 504, and 505 had EROD activities >15 pmol/min/mg for 

male and female fish. Basin-wide means for both males (23.1 

pmol/min/mg) and females (18.4 pmol/min/mg) exceeded the 

basal EROD level. Two juvenile largescale sucker had EROD 

rates of 9.3 pmol/min/mg (Station 46) and 28.2 pmol/min/mg 

(Station 505). 

EROD in Other Fishes 

Hepatic EROD activity was measured in longnose sucker, 

northern pikeminnow, rainbow trout, and walleye, in addition 

to the target species (bass, carp, and largescale sucker). EROD 

activity varies greatly among fishes, and there are relatively 

few reports of basal activity against which to judge the relative 

induction associated with many of these results (Whyte and 

others, 2000). Those for which such comparisons can be made 

are summarized below. 

Longnose sucker were collected from Stations 98 and 117 

in the UCR. Only one female and one male were collected 

from Station 98, and the EROD activity was 3.0 and 7.3 pmol/ 

min/mg, respectively. EROD activity ranged from 2.4-11.0 

pmol/min/mg in females, 18.0 pmol/min/mg in a male, and 

4.1-6.6 pmol/min/mg in juvenile longnose sucker collected at 

Station 117. These values are <2-fold lower than previously 

reported basal activities for this species (Kloepper-Sams and 

Benton, 1994; Kloepper-Sams and others, 1994; Swanson 

and others, 1992). Northern pikeminnow were collected 

from Stations 43, 44, 46, 502, 503, and 505. EROD activities 

ranged from 0.18-102 pmol/min/mg in females with fish from 

Stations 46 and 503 having the greatest mean EROD activity. 

EROD activity in males ranged from 0.18-26.1 pmol/min/mg 

with Station 503 having the greatest station mean. These 

levels are similar to those previously reported in fish from 

the Willamette River in the LCR (Curtis and others, 1993). 

Rainbow trout, collected exclusively from Station 504, had 

EROD activities of 1.2-25.2 pmol/min/mg in females, 6.9-12.0 

pmol/min/mg in males, and 4.4-41.5 pmol/min/mg in juveniles, and were less than many of the EROD activities in other 

rainbow trout field studies (many, reviewed by Whyte and 

others, 2000). Walleye were collected from Stations 98 and 

505. Walleye from Station 98 had EROD activities of 9.5-51.8 

pmol/min/mg for females, 16.7-26.3 pmol/min/mg for males, 

and 25.8-30.7 pmol/min/mg for juveniles. These levels are 

similar to basal activities for this species reported by Williams 

and others (1997). 

Accumulative Contaminants, H4IIE, and EROD 

Activity: Summary 

Concentrations of most contaminants measured in fish 

from the CRB were low with a few exceptions. Most elemental contaminant concentrations were relatively low; however, 

Pb, Hg, and Se exceeded protective criteria at multiple stations. Concentrations of Pb >4 μg/g ww were measured in 

largescale sucker at Stations 98 and 504 in the UCR. These 

stations are located downstream from a smelting complex. 

Concentrations of Hg exceeded 0.3 μg/g ww, a threshold value 

thought to cause reproductive impairment to loons, in predatory fish at various stations throughout the CRB. All samples 

from Station 97 and bass from Stations 43 and 503 exceeded 

0.06 μg/g ww for Se, the threshold toxic to piscivorous 

wildlife. Comparison of 1997 concentrations with historical 

NCBP data revealed that most temporal trends for organochlorine and elemental contaminants were decreasing, continuing 

two-decade trends for accumulative contaminants at these sta­
60 Environmental Contaminants and their Effects on Fish 

tions (Table 17). However, concentrations of As, Cd, and Se 

for select species had increasing concentrations in 1997. 

Organochlorines were measured at concentrations of 

concern at some sites within the CRB. DDT-derived residues 

(mostly as p,p’-DDE) were detected at all stations with the 

exception of Station 117. Concentrations potentially toxic to 

fish-eating wildlife (>1.0 μg/g ww) occurred in fish from stations located in the MCR (Stations 44, 97, and 503). However, comparison of 1997 concentrations with historical data 

revealed decreasing trends for p,p’-DDE including Stations 

44 and 97 (Table 17). These higher concentrations are most 

likely due to past DDT use in the agricultural areas in the 

watersheds. These stations had little or no p,p’-DDT detected, 

indicating the continued weathering of residual DDT rather 

than the input of new material. Toxaphene and mirex were 

detected at trace concentrations in largescale sucker from Station 506 in the lower CRB. 

Cyclodiene pesticides were present at fewer stations and 

lower concentrations than DDT. All stations had chlordane 

residues that were less than the criteria for protecting predatory fish and fish-eating birds (0.1 μg/g ww). Endrin was 

≤LOD in fish samples at all stations. Dieldrin was detected at 

trace concentrations in the lower SR and LCR, and concentrations >0.02 μg/g ww were measured in fish from three stations 

located in the lower SR and Yakima River. Concentrations of 

all other organochlorine pesticides were <LOD. 

Concentrations of total PCBs were also generally low. 

PCBs were detected at 81% of the stations; however, only 

Station 503 had a sample with concentrations >1.0 μg/g ww. 

Similar to dieldrin, the greatest concentrations occurred in fish 

from the lower SR and LCR. Concentrations of PCBs were 

generally lowest in the upper SR and UCR. HCB was only 

detected in trace quantities at two stations. 

Dioxin-like contaminants, as indicated by the H4IIE rat 

hepatoma cell bioassay, were detected at all stations except 

Station 117. Based on the potential for reproductive impairment and biomagnification factors, H4IIE bioassay values 

in fish >5 pg/g may be hazardous to avian and mammalian 

wildlife which consume fish. Multiple stations throughout the 

CRB had concentrations >5 pg/g. Female carp from Station 

96 had the highest measured TCDD-EQ concentration (43 pg/ 

g) of the study, being four times greater than any other sample. 

Dioxin-like activity was not well correlated with concentrations of total PCBs, suggesting the presence of one or more 

other dioxin-like compounds. 

EROD activity can be influenced by numerous factors 

including species (Addison and others, 1991; Segner and others, 1995), fish size and age (Khan and Payne, 2002b; Peters 

and Livingstone, 1995; Pluta, 1993), nutrition (Ankley and 

others, 1989), reproductive status (Campbell and others, 1976; 

Schrek and Hopwood, 1974), water temperature (Khan and 

Payne, 2002a; Machala and others, 1997), and capture activity 

(Machala and others, 1997). Results of the EROD assay determined that elevated activities were not consistent among target 

species. Bass had elevated EROD activity at one station in the 

UCR and two stations in the lower Willamette River. EROD 

activity in male carp was elevated in the lower SR and MCR; 

EROD activity in male and female carp was elevated at one 

station in the lower Willamette River. Largescale sucker had 

EROD activity greater than basal levels throughout the CRB. 

EROD activities did not correlate to either PCBs or TCDDEQs for bass, carp, or sucker. This suggests that at some 

stations high EROD activities were caused by exposure of the 

fish to labile contaminants that did not survive the reactive 

cleanup used to process the samples for the H4IIE bioassay. 

Fish Health Indicators 

Organism-Level Indicators 

External Gross Lesions 

External gross lesions were identified during the fish 

health examination in the field. The fish health assessment 

found that 74% of all fish collected from the CRB had external 

gross lesions (abnormalities). These lesions were categorized by location including lesions on the body surface, eyes, 

opercles, and fins. The percentage of fish with external lesions 

ranged from 50% at Station 98 to 100% at Station 44 (Table 

22). Statistical analyses found no significant differences 

between genders for carp, bass, or largescale sucker; therefore, genders were combined for data analysis. The percentage of bass with lesions (67%) was less than the basin-wide 

percentage for all species (74%). Fish from Stations 42, 43, 

and 503 had gross lesions on <50% of those surveyed (Table 

22). The basin-wide percentage of carp with lesions (83%) 

was the greatest of all the target species, and greater than carp 

from other basins sampled by the BEST program (Schmitt 

and others, 2002b; 2004). All stations except Station 97 

had >75% of carp with gross lesions (Table 22). Largescale 

sucker had lesions on 78% of the fish surveyed and all stations 

had percent lesions >60% (Table 22). Most the lesions were 

attributed to eroded, frayed, hemorrhagic, or emboli fins. The 

percent of lesions for these fish are high and caution needs to 

be used when interpreting these data. Many lesions identified 

are not a result of exposure to environmental contaminants 

but are more likely due to holding time in nets prior to fish 

processing or normal wear as a fish ages. 

Health Assessment Index 

The health assessment index (HAI) is a systematic 

method to identify external and internal lesions for each fish 

during the field health assessment. A higher HAI score indicates a greater number of lesions were identified on the fish. 

The HAI may vary depending on gender and gonadal stage. 
—Continued 

Results and Discussion 61 

Table 22. Number and location of external lesions identified on fish collected in the Columbia River Basin in 1997. Body, eyes, 

opercles, and fins of each fish were examined for the presence of lesions, and the proportion of fish with lesions was calculated. 

Stations are grouped by sub-basin and ordered upstream to downstream. 

Lesion Location 

Station and Species n Body Eyes Opercles Fins Total no. 

w/lesions Proportion 

Upper Columbia River (UCR) 

Creston, MT (117) 

All 44 8 0 4 17 24 0.545 

Bass 21 2 0 1 12 12 0.571 

 Largescale sucker 10 3 0 0 3 6 0.600 

Longnose sucker 13 3 0 3 2 6 0.462 

Northport, WA (504) 

All 40 9 6 2 14 23 0.575 

 Largescale sucker 20 8 4 2 10 17 0.850 

 Rainbow trout 20 1 2 0 4 6 0.300 

Grand Coulee, WA (98) 

All 38 3 15 0 7 19 0.500 

 Largescale sucker 21 2 13 0 4 15 0.714 

Longnose sucker 1 0 1 0 1 1 1.000 

Walleye 16 1 1 0 2 3 0.188 

Snake River (SR) 

Hagerman, ID (41) 

All 36 20 3 12 34 34 0.944 

 Common Carp 20 8 1 5 20 20 1.000 

Bass 16 12 2 7 14 14 0.875 

Riggins, ID (43)

 All 41 5 5 0 21 26 0.634 

Bass 7 1 0 0 3 3 0.429 

 Largescale sucker 20 2 2 0 11 13 0.650 

 Northern pikeminnow 14 2 3 0 7 10 0.714 

Lewiston, ID (42) 

All 30 7 3 4 12 17 0.567 

 Common Carp 17 7 2 4 9 13 0.765 

Bass 13 0 1 0 3 4 0.308 

Ice Harbor Dam, WA (96) 

All 28 8 4 1 16 20 0.714 

 Common Carp 21 8 4 1 12 16 0.762 

Bass 7 0 0 0 4 4 0.571 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) 

All 36 9 7 2 26 28 0.778 

 Common Carp 21 7 3 1 17 18 0.857 

Bass 5 0 1 0 2 2 0.400 

 Northern pikeminnow 10 2 3 1 7 8 0.800 

Pasco, WA (97)

 All 35 3 3 1 13 19 0.543 

 Common Carp 20 2 2 1 6 10 0.500 

Bass 15 1 1 0 7 9 0.600 

Granger, WA (44) 

All 41 11 11 3 41 41 1.000 

 Common Carp 20 6 5 3 20 20 1.000 

Bass 15 2 2 0 15 15 1.000 

 Northern pikeminnow 6 3 4 0 6 6 1.000 

Lower Columbia River (LCR) 

Cascade Locks, OR (46) 

All 23 5 3 0 17 18 0.783 

 Largescale sucker 21 5 3 0 16 17 0.810 

 Northern pikeminnow 2 0 0 0 1 1 0.500 

Warrendale, OR (502) 

All 38 2 11 2 28 32 0.842 

 Common Carp 20 1 3 1 17 17 0.850 

Bass 4 0 1 0 4 4 1.000 

 Largescale sucker 3 0 0 1 1 2 0.667 

 Northern pikeminnow 11 1 7 0 6 9 0.818 
62 Environmental Contaminants and their Effects on Fish 

Table 22. Number and location of external lesions identified on fish collected in the Columbia River Basin in 1997. Body, eyes, 

opercles, and fins of each fish were examined for the presence of lesions, and the proportion of fish with lesions was calculated. 

Stations are grouped by sub-basin and ordered upstream to downstream.—Continued 

Lesion Location 

Station and Species n Body Eyes Opercles Fins 

w

Total no. 

/lesions Proportion 

Vancouver, WA (506) 

All 22 9 0 4 12 17 0.773 

Bass 1 0 0 1 0 1 1.000 

 Largescale sucker 21 9 0 3 12 16 0.762 

Oregon City, OR (45) 

All 42 14 4 2 28 36 0.857 

 Common Carp 14 5 1 0 10 13 0.929 

Bass 22 5 3 2 13 18 0.818 

Largescale sucker 6 4 0 0 5 5 0.833 

Portland, OR (505) 

All 33 14 3 0 28 29 0.879 

Bass 8 2 1 0 5 6 0.750 

 Largescale suckers 22 12 1 0 21 21 0.955 

 Northern pikeminnow 2 0 1 0 2 2 1.000 

 Walleye 1 0 0 0 0 0 0.000 

Beaver Army Terminal, OR (501) 

All 33 15 1 1 22 29 0.879 

 Common Carp 4 0 0 1 3 4 1.000 

 Largescale suckers 16 7 1 0 11 13 0.813 

 Northern pikeminnow 13 8 0 0 8 12 0.923 

Basin Total 

All 560 142 79 38 336 412 0.735 

 Common carp 157 44 21 17 114 131 0.834 

Bass 134 25 12 11 82 92 0.687 

 Largescale sucker 160 52 24 6 94 125 0.781 

 Northern pikeminnow 58 16 18 1 37 48 0.828 

 Longnose sucker 14 3 1 3 3 7 0.500 

 Walleye 17 1 1 0 2 3 0.176 

 Rainbow trout 20 1 2 0 4 6 0.300 

The gender and gonadal stage did not influence HAI in bass, 

carp, or largescale sucker (Table 20). Therefore, the HAI data 

for genders were combined for data analysis. 

Most HAI values for bass (80%) ranged from 0-100 

(Table 23; Fig. 12). Mean HAI values ranged from 30-63 for 

fish at all stations except Stations 44 (85), 45 (87), and 41 

(135) (Fig. 12). Bass with HAI ratings >120 were collected 

from Stations 41, 44, 45, 503, and 505. Bass collected from 

Stations 41, 44, and 45 had consistently higher HAI values 

than bass collected from the other stations (Fig. 12). Blazer 

and others (2002) determined similar HAI values for bass in 

the MRB with mean station HAI ranging from 14-130 and 

a reference station with an HAI score of approximately 50. 

Other studies have designated HAI values <20 as un-impacted 

(Schmitt, 2002a). 

Most HAI values for carp (82%) ranged from 0-70, indicating most carp were identified as having zero to three lesions 

(Fig. 12; Table 23). Mean HAI data for fish at all stations 

ranged from 42-64 with the exception of Station 501 (Fig. 

12). Stations that had fish with HAI >110 included Stations 

44, 96, 502, and 503, although these data do not indicate that 

any particular station was notable for numerous abnormalities in carp (Fig. 12). These data are similar to HAI data for 

carp from the MRB (Blazer and others, 2002), which determined carp to have mean station HAI values of approximately 

0-90 for females and 1-95 for males. The RGB BEST study 

determined most individual carp and bass had HAI values <60 

(Schmitt and others, 2004). 

Most (95%) of HAI values for largescale sucker were 0­

100 (Fig. 12; Table 23), and station mean values ranged from 

30-63. Largescale sucker from Stations 43, 117, and 502 had 

HAI values <70 (Fig. 12). Two or more sucker at the remaining stations had HAI values ≥100. However, HAI among 

stations did not differ for largescale sucker (Table 20). HAI 

values ranging from 0-60 for individual fish for largescale 

sucker from the LCR have been reported by the Bi-State Water 

Quality Program (Tetra Tech Inc., 1996). 

Condition and Organosomatic Indices 

These indices are calculated from body and organ weight 

in individual fish and considered general indicators of the 

overall health of the fish and alterations of these indices may 

be indicative of effects resulting from exposure to contaminants (Schmitt and Dethloff, 2000). These indices can vary 

among species, gender, and developmental stage. 
—Continued 

63 

Table 23. Distribution of Health Assessment Index (HAI) scores among bass, common carp, and largescale sucker collected in the Columbia River Basin in 1997. Station totals 

where HAI scores were not available for all individual fish are noted with an asterisk (*). 

HAI Score 

Species and station 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Total 

BassUpper Columbia River (UCR) 

Creston, MT (117) 

Snake River (SR) 

Hagerman, ID (41) Riggins, ID (43) Lewiston, ID (42) Ice Harbor Dam, WA (96) 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) Pasco, WA (97) Granger, WA (44) 

Lower Columbia River (LCR) 

Warrendale, OR (502) Vancouver, WA (506) Oregon City, OR (45) Portland, OR (505) 

Basin Total Common CarpSnake River (SR) 

Hagerman, ID (41) Lewiston, ID (42) Ice Harbor Dam, WA (96) 

3

0

0

3

0

0

0

0

0

0

0

0

6

0

2

3 

3

0

0

1

0

0

1

1

0

0

0

1

7

0

2

0 

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0 

5

0

4

4

2

3

1

2

0

0

1

2

24

0

4

1 

7

1

2

2

3

1

2

2

2

1

4

0

27

8

2

5 

1

0

0

0

0

0

0

0

0

0

0

0

1

3

1

0 

1

0

0

3

1

0

5

0

0

0

3

1

14

0

0

3 

1

0

1

0

1

0

3

2

2

0

2

2

14

4

1

5 

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

0 

0

2

0

0

0

0

1

0

0

0

2

0

5

0

0

1 

0

1

0

0

0

0

1

2

0

0

4

1

9

3

4

1 

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0 

0

0

0

0

0

0

0

0

0

0

1

0

1

0

0

1 

0

1

0

0

0

1

0

6

0

0

3

1

12

0

0

0 

0

4

0

0

0

0

0

0

0

0

0

0

4

0

0

1 

0 0 0 21 

0 4 

0 0 

0 0 

0 0 

3 16 

0 7 

0 13 

0 7 

0 0 

0 0 

0 0 

0 5 

0 14* 

0 15 

0 0 

0 0 

0 2 

0 0 

0 6 

0 4 

0 1 

0 22 

0 8 

3 133 

0 0 

0 0 

0 0 

0 20 

0 17 

0 21 

Results and Discussion 
64 

Table 23. Distribution of Health Assessment Index (HAI) scores among bass, common carp, and largescale sucker collected in the Columbia River Basin in 1997. Station totals 

where HAI scores were not available for all individual fish are noted with an asterisk (*).—Continued 

HAI Score 

Species and station 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Total 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) Pasco, WA (97) Granger, WA (44) 

Lower Columbia River (LCR) 

Warrendale, OR (502) Oregon City, OR (45) 

Beaver Army Terminal, OR (501) 

Basin Total Largescale sucker Upper Columbia River (UCR) 

Creston, MT (117) Northport, WA (504) Grand Coulee, WA (98) 

Snake River (SR) 

Riggins, ID (43) 

Lower Columbia River (LCR) 

Cascade Locks, OR (46) Warrendale, OR (502) Vancouver, WA (506) Oregon City, OR (45) Portland, OR (505) Beaver Army Terminal, OR (501) 

Basin Total 

1

2

0

0

0

0

8

1

1

2

0

1

0

2

0

0

1

8 

3

0

3

3

2

3

16

3

1

0

1

4

1

1

1

2

2

16 

1

0

0

0

0

0

2

0

0

0

0

0

0

1

0

0

0

1 

2

6

1

2

1

0

17

3

3

5

7

2

1

4

1

1

3

30 

5

3

3

6

2

0

34

0

2

0

8

8

0

4

0

8

3

33 

0

1

0

0

0

0

5

0

0

0

0

0

0

1

0

0

0

1 

0

6

0

1

1

1

12

3

3

4

3

2

1

2

0

0

1

19 

5

2

7

4

6

0

34

0

4

3

1

2

0

1

2

7

3

23 

0

0

2

0

0

0

4

0

1

0

0

0

0

1

0

0

0

2 

0

0

1

2

2

0

6

0

3

3

0

0

0

1

0

0

0

7 

2

0

0

0

0

0

10

0

0

0

0

1

0

2

2

3

3

11 

0

0

1

1

0

0

2

0

1

0

0

0

0

0

0

0

0

1 

1

0

1

0

0

0

3

0

0

2

0

0

0

0

0

1

0

3 

0

0

1

1

0

0

2

0

0

0

0

1

0

1

0

0

0

2 

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0 

1 0 

0 0 

0 0 

0 0 

0 0 

0 0 

1 0 

0 0 

1 0 

1 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

2 0 

0 21 

0 20 

0 20 

0 20 

0 14 

0 4 

0 157 

0 10 

0 20 

0 20 

0 20 

0 21 

0 3 

0 21 

0 6 

0 22 

0 16 

0 159 

Environmental Contaminants and their Effects on Fish 
S

S

SSSSS

S

SSS

SS

S

SS

65 

180 Bass 

150 

120 

90 

60 

30 

0 

180 Carp 

150 

120 

90 

60 

30 

0 

180 

150 

120 

90 

60 

30 

0 

Upper 

Snake R. 

Lower 

Largescale sucker 

Columbia R. 

MidColumbia R. Columbia R. 

117 504

98

41

434296

503

974446

502 506

45

505

501 

Station 

Figure 12. Health assessment index (HAI) score by station in bass 

(Micropterus sp.), carp, and largescale sucker collected in the 

Columbia River Basin in 1997. Shown for each group are points 

representing individual fish and the mean (red horizontal line), 

median (black horizontal line), interquartile range (box), and the 

10th and 90th percentiles (whiskers). Stations are ordered from 

upstream to downstream and are grouped by sub-basin. See 

Table 3 for station descriptions. 

Condition and Organosomatic Indices in Bass 

The gender and/or developmental stage influenced 

condition factor and organosomatic indices in bass (Table 20). 

Therefore, the data for male and female bass were examined 

separately for CF and HSI so as not to confound the potential 

Results and Discussion 

effects other variables may have on the fish health indicators 

with the effects caused by gender or developmental stage. 

The basin-wide mean CF for female bass was 1.6, and station 

means ranged from 1.3 at Station 42 to 1.8 at Station 503 

(Table 24; Fig. 13). Female bass from Station 502 (n=1) had a 

CF of 2.1. Stations 41, 44, 97, 117, 502, and 503 had fish with 

a CF >1.9. Across all stations, 91% of bass had CF between 

1.1-1.9 (Fig. 13), the range of CF in small- and largemouth 

bass in a nationwide survey (Carlander, 1977). These data are 

similar to a more recent study which determined female largemouth bass in a laboratory control group to have CF between 

1.2 and 1.3 (Sepúlveda and others, 2001). Female bass had 

mean station CF that ranged from approximately 1.0-2.0 in the 

MRB (Blazer and others, 2002) and approximately 1.5 in the 

RGB (Schmitt and others, 2004). CF for female bass varied 

significantly among stations in the CRB (Table 20). 

Male bass had a basin-wide mean CF of 1.5 with station means ranging from 1.3 at Station 42 to 1.7 at Station 96 

(Table 24). Stations 41, 43, 96, and 117 had fish with a CF 

>1.9; Stations 43, 97, and 117 had fish with a CF <1.0. Most 

(86%) male bass had CF between 1.1-1.9 (Fig. 13). Sepúlveda 

and others (2001) determined male largemouth bass in a 

laboratory control group to have CF between 1.1-1.3. CF for 

male bass did vary among stations in the CRB (Table 20). 

The mean station CF values in the CRB were similar to those 

found in male bass from the MRB (Blazer and others, 2002), 

RGB (Schmitt and others, 2004), and other locations across 

the U.S. (Carlander, 1977). 

Of the three target species, only bass have discrete livers. 

Thus, HSI was only calculated for bass. The mean HSI for 

female bass in the basin was 1.4%, and station means ranged 

from 1.0% at Station 502 to 2.3% at Station 503 (Table 25). 

With the exception of Station 503, all station means were 

<1.7% for CF. Indices >2.1% were calculated for fish at Stations 43, 45, 97, and 503; however, most female bass (90%) 

had HSI between 0.9-2.4% (Fig. 13). Station 503 was the 

only station that consistently had female bass with HSI >2.0%, 

while Station 502 (n=1) had the minimum HSI. These data 

were similar to previous studies. Female bass had HSI station 

means ranging from 0.6-2.0% in the MRB (Blazer and others, 

2002) and were approximately 1.0% in the RGB (Schmitt 

and others, 2004). Gingerich (1982) determined a comparative range for normal liver weight in fish to be 1-3% of the 

total body weight. In other studies, HSI in female bass from 

a control group ranged from 0.9-1.8% (Sepúlveda and others, 

2001; 2003). 

The mean basin-wide HSI for male bass was 1.4%. Station means ranged from 1.0% at Station 97 to 2.0% at Station 

43 for male bass (Table 25). Station means did not exceed 

1.7% with the exception of fish at Station 43. Indices >2.2% 

were calculated for male bass at Stations 43, 44, and 117; 

however, most male bass (90%) had HSI between 0.8-2.2% 

(Fig. 13). Several laboratory studies determined male largemouth bass to have HSI ranging from 0.7-1.7% (Sepúlveda 

and others, 2001; 2003). HSI in male bass varied among stations in the CRB (Table 20). HSI calculated for male bass in 
-- -- --

-- -- --

66 Environmental Contaminants and their Effects on Fish 

Table 24. Arithmetic mean of condition factor (CF) by station, number of samples ( n ), minimum 

(min.), maximum (max.), and standard error (SE) in the target species collected in the Columbia 

River Basin in 1997. Stations are grouped by taxon and sub-basin and ordered upstream to 

downstream. The maximum station mean for each taxon is shown in bold.—Continued 

Taxon and Station n Mean Min. Max. SE 

Bass - female 

Basin total 74 1.57 1.21 2.15 0.03 

Upper Columbia River (UCR) 

Creston, MT (117) 11 1.67 1.29 2.13 0.08 

Snake River (SR) 

Hagerman, ID (41) 9 1.67 1.45 1.92 0.06 

Riggins, ID (43) 3 1.46 1.23 1.81 0.18 

Lewiston, ID (42) 5 1.34 1.23 1.45 0.04 

Ice Harbor Dam, ID (96) 4 1.55 1.41 1.64 0.05 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) 3 1.79 1.58 1.95 0.11 

Pasco, WA (97) 9 1.59 1.29 2.15 0.09 

Granger, WA (44) 9 1.53 1.21 1.98 0.08 

Lower Columbia River (LCR) 

Warrendale, OR (502) 1 2.08 

Oregon City, OR (45) 15 1.46 1.29 1.68 0.03 

Portland, OR (505) 5 1.56 1.39 1.80 0.08 

Bass - male 

Basin total 60 1.51 0.59 2.21 0.04 

Upper Columbia River (UCR) 

Creston, MT (117) 10 1.54 0.71 2.21 0.13 

Snake River (SR) 

Hagerman, ID (41) 7 1.61 1.42 1.97 0.07 

Riggins, ID (43) 4 1.38 0.83 1.99 0.24 

Lewiston, ID (42) 7 1.33 1.22 1.49 0.03 

Ice Harbor Dam, ID (96) 3 1.75 1.42 1.95 0.17 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) 2 1.69 1.52 1.87 0.17 

Pasco, WA (97) 6 1.45 0.59 1.81 0.18 

Granger, WA (44) 6 1.52 1.37 1.60 0.03 

Lower Columbia River (LCR) 

Warrendale, OR (502) 3 1.59 1.54 1.67 0.04 

Vancouver, WA (506) 1 1.63 

Oregon City, OR (45) 6 1.48 1.33 1.62 0.05 

Portland, OR (505) 3 1.50 1.35 1.59 0.07 

Carp 

Basin total 157 1.36 0.91 1.91 0.01 

Snake River (SR) 

Hagerman, ID (41) 20 1.38 1.18 1.63 0.03 

Lewiston, ID (42) 7 1.12 1.04 1.23 0.07 

Ice Harbor Dam, ID (96) 21 1.39 0.91 1.91 0.04 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) 21 1.32 0.99 1.82 0.04 

Pasco, WA (97) 20 1.29 0.93 1.53 0.03 

Granger, WA (44) 20 1.23 1.01 1.53 0.03 

Lower Columbia River (LCR) 

Warrendale, OR (502) 20 1.39 1.16 1.66 0.03 

Oregon City, OR (45) 14 1.46 1.21 1.75 0.04 

Beaver Army Terminal, OR (501) 4 1.30 1.16 1.41 0.05 
Results and Discussion 67 

Table 24. Arithmetic mean of condition factor (CF) by station, number of samples ( n ), minimum 

(min.), maximum (max.), and standard error (SE) in the target species collected in the Columbia 

River Basin in 1997. Stations are grouped by taxon and sub-basin and ordered upstream to 

downstream. The maximum station mean for each taxon is shown in bold.—Continued 

Taxon and Station n Mean Min. Max. SE 

Largescale Sucker 

Basin total 158 0.94 0.45 1.67 0.01 

Upper Columbia River (UCR) 

Creston, MT (117) 10 0.97 0.67 1.16 0.04 

Northport, WA (504) 19 1.04 0.90 1.23 0.02 

Grand Coulee, WA (98) 20 0.86 0.70 1.06 0.02 

Snake River (SR) 

Riggins, ID (43) 20 0.92 0.84 1.04 0.01 

Lower Columbia River (LCR) 

Cascade Locks, OR (46) 21 0.96 0.66 1.13 0.02 

Warrendale, OR (502) 3 0.91 0.84 0.99 0.04 

Vancouver, WA (506) 21 0.95 0.80 1.25 0.02 

Oregon City, OR (45) 6 1.20 0.97 1.67 0.10 

Portland, OR (505) 22 0.87 0.45 1.07 0.04 

Beaver Army Terminal, OR (501) 16 0.92 0.78 1.06 0.02 

the CRB were similar to previous studies (Blazer and others, 

2002; Gingerich, 1982), but greater than male bass in the RGB 

(Schmitt and others, 2004). 

Overall, none of the CRB stations had consistently 

elevated SSI values. The basin-wide mean for SSI in 

bass was 0.15%, and station means ranged from 0.10% 

at Station 96 to 0.25% at Station 42 (Table 26). Stations 42 and 505 had fish with SSI >0.60%; however the 

majority (95%) of fish SSI were 0.06-0.34% (Fig. 13). The 

SSI in bass did not vary significantly among stations (Table 

20). In previous studies, bass from the MRB had similar SSI 

to those found in the CRB with station mean SSI ranging from 

0.09-0.24% (Blazer and others, 2002). Similar results were 

reported by Schmitt and others (2004) for bass in the RGB 

with station means ranging from approximately 0.1-0.2%. 

Condition and Organosomatic Indices in Carp 

The gender and/or developmental stage influenced CF but 

not SSI in carp (Table 20). The data for male and female carp 

were also examined separately for SSI, but combined for CF. 

The basin-wide mean CF was 1.4 for carp, and station means 

ranged from 1.2 at Station 44 to 1.9 at Station 42 (Table 24). 

All individual fish had CF values ranging from 0.9-1.9 (Fig. 

14). CF did not vary significantly among stations for carp 

(Table 20). CF data from the CRB were similar to data from 

previous studies. CF station means in carp ranged from 1.1-

1.5 in the MRB (Blazer and others, 2002) and 1.2-1.5 in the 

RGB (Schmitt and others, 2004). Carlander (1969) performed 

a survey of carp across the U.S. and determined the mean CF 

range from 1.2 to >2.0. 

The basin-wide mean for SSI in female carp was 0.24% 

(Table 26). Station means for female carp ranged from 0.15% 

at Station 42 to 0.39% at Station 45, and all other station 

means were 0.2-0.3% (Table 26). Station 42 had three fish 

with SSI <0.01%, and Stations 45 and 97 had one individual 

fish each with an SSI >0.5% (Fig. 14). SSI for female carp 

increased upstream to downstream in CRB, supporting that 

SSI did vary significantly among stations (Table 20). Female 

carp from the MRB had slightly greater SSI than carp from 

the CRB, with station means ranging from 0.09-0.87% (Blazer 

and others, 2002), but station means in female carp from the 

RGB (approximately 0.1-0.3%) were similar to SSI in the 

CRB (Schmitt and others, 2004). 

Male carp had greater SSI values compared to female 

carp having a basin-wide mean of 0.34%, and station means 

ranged from 0.22% at Station 41 to 0.47% at Station 45 (Table 

26). Multiple fish from Stations 42, 45, 501, and 502 had SSI 

>0.60% (Fig. 14). Stations 45 and 502 consistently had male 

carp with SSI values >0.3%, recalling Station 45 was previously noted for relatively high SSI for female carp. Similar to 

female carp, SSI in male carp varied significantly among stations increasing upstream to downstream (Fig. 14; Table 20). 

SSI station means in male carp from the MRB ranged from 

0.04-0.50% (Blazer and others, 2002), which is less than the 

SSI for carp from the CRB. Male carp from the RGB had SSI 

that ranged from 0.1-0.4% which is similar to those measured 

in the CRB (Schmitt and others, 2004). 

Condition and Organosomatic Indices in Largescale 

Sucker 

Gender and/or developmental stage did not influence fish 

health indicators in largescale sucker (Table 20), so the data 

for males and females were combined for data analysis. 

The basin-wide mean for largescale sucker CF was 0.9. 

The mean CF was greatest (1.2) in largescale sucker at Station 

45, while all other station means were <1.0 (Table 24). All 

fish had CF values <1.3 with the exception of one fish from 

Station 45 (Fig. 15). Certain largescale sucker had greater CF 
2.0 

3.0 

0.0 

1.2 

68 Environmental Contaminants and their Effects on Fish 

2.5 

3.5 

CF-female 

CF-male 

HSI-female 

HSI-male 

values, but CF values did not differ significantly among stations (Table 20). Previous studies examining CF in sucker are 

limited. The state of Minnesota set standards that considered 

white sucker with CF <1.0 to be in poor condition (Carlander, 1.5 

1969). 

Mean SSI values were similar among CRB stations 1.0 

although some individual values increased the variability of 

2.5 the data. The basin-wide mean SSI for largescale sucker was 

0.25% and station means ranged from 0.17% at Station 501 2.0 to 0.37% at Station 117 (Table 26). Spleen weights were not 

available for largescale sucker from Station 43. Two fish from 1.5 Station 117 and one fish from Station 504 had SSI >0.6%, 

and largescale sucker at Station 117 had the greatest vari- 1.0 ability (SE±0.06) in SSI data. SSI <0.1% were calculated for 

fish from Stations 46, 501, and 506. Most values (91%) were 0.5 

between 0.12-0.43% (Fig. 15). Mean station SSI in largescale 

sucker decreased upstream to downstream in CRB, supporting that SSI did vary significantly among stations (Table 20). 

Previous studies on SSI in largescale sucker have not been 

documented. Fish health indicators for non-target species are 

located in Appendix 2. 

Cellular and Histopathological Indicators 

2.5 

2.0 

1.5 

1.0 

0.5 

% 

%

%

3.0 

2.5 

2.0 

1.5 

1.0 

0.5 

Macrophage aggregates (MA) are believed to house 

endogenous and exogenous waste products and are active in 

the immune responses to these materials (Schmitt and Dethloff, 2000). Three macrophage aggregate parameters, density or number of aggregates per mm2 (MAMM), mean size 

of aggregates in μm2 (MEANAREA), and percent of tissue 

occupied by macrophage aggregates (TISSOC) were analyzed 

for carp, bass, and largescale sucker in this study. Gender 

1.0 

Mid 

SSI 

Upper 

Columbia R. Snake R. Columbia R. 

Lower 

Columbia R. 

carp, and largescale sucker (Table 20). The MA data were 

examined separately, where appropriate, so as not to confound 

the potential effects other variables may have on the immune 

0.8 

0.6 biomarkers with the effects caused by gender or age. 

0.4 

0.2 

MAMM 

and age influenced macrophage aggregate parameters in bass, 

Gender and age did not influence MAMM in bass, carp, 

and largescale sucker (Table 20); therefore, genders were 

117 504

98

41

434296

503

97

44

46

502

506

45

505

501 

combined for data analysis. The basin-wide mean MAMM 

for bass was 6.3 MA/mm2

, and station means ranged from 4.1 

MA/mm2 at Station 502 to 9.5 MA/mm2 at Station 43 in bass 

(Table 27). Individual MAMM in bass ranged from 0.6-19.4 

MA/mm2 (Fig. 16). MAMM values >15 MA/mm2 were measured in bass at Stations 41 and 117. Most (90%) of bass had 

MAMM of 1.8–12.4 MA/mm2; Stations 41, 42, 43, 44, and 

117 had fish with MAMM >12.4 MA/mm2. MAMM did not 

differ significantly among stations (Table 20). Age-adjusted 

MAMM values were computed because age was a significant 

variable for other MA parameters in bass (Tables 20 and 28). 

Age-adjusted station order was similar to non-adjusted station 

Station 

Figure 13. Fish health indicators by station in female and male 

bass (Micropterus sp.) collected in the Columbia River Basin in 

1997. Indicators include condition factor (CF), hepatosomatic 

index (HSI), and splenosomatic index (SSI). Females and males 

were plotted separately when analysis-of-variance modeling 

determined gender was a significant factor. Shown for each 

group are points representing individual fish and the mean (red 

horizontal line), median (black horizontal line), interquartile range 

(box), and the 10th and 90th percentiles (whiskers). Stations are 

ordered from upstream to downstream and are grouped by subbasin. See Table 3 for station descriptions. 
Results and Discussion 69 

Table 25. Arithmetic mean of hepatosomatic index (HSI; %) by station, number of samples (n ), 

minimum (min.), maximum (max.), and standard error (SE) in bass collected in the Columbia River 

Basin in 1997. Stations are grouped by gender and sub-basin and ordered upstream to downstream. The maximum station mean for each gender is shown in bold. 

Taxon and Station n Mean Min. Max. SE 

Bass - female 

Basin total 73 1.42 0.53 2.62 0.05 

Upper Columbia River (UCR) 

Creston, MT (117) 11 1.23 0.98 1.72 0.07 

Snake River (SR) 

Riggins, ID (43) 3 1.72 1.11 2.48 0.40 

Lewiston, ID (42) 4 1.63 1.21 2.04 0.19 

Ice Harbor Dam, ID (96) 4 1.42 1.15 1.71 0.12 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) 3 2.33 2.27 2.44 0.05 

Pasco, WA (97) 9 1.20 0.53 2.62 0.19 

Granger, WA (44) 9 1.15 0.88 1.44 0.05 

Lower Columbia River (LCR) 

Warrendale, OR (502) 1 1.00 -- --

Oregon City, OR (45) 15 1.65 1.15 2.37 0.10 

Portland, OR (505) 5 1.62 1.40 1.90 0.09 

Bass - male 

Basin total

Upper Columbia River (UCR)

Creston, MT (117)

Snake River (SR)

Hagerman, ID (41)

Riggins, ID (43)

Lewiston, ID (42)

Ice Harbor Dam, ID (96)

Middle Columbia River (MCR)

Vernita Bridge, WA (503)

Pasco, WA (97)

Granger, WA (44)

Lower Columbia River (LCR)

Warrendale, OR (502)

Vancouver, WA (506)

Oregon City, OR (45)

Portland, OR (505)

60 1.36 0.73 3.17 0.05 

10 1.32 0.79 2.33 0.13 

7 1.27 0.76 1.90 0.14 

4 2.00 1.57 3.17 0.39 

7 1.31 1.17 1.57 0.06 

3 1.09 0.99 1.17 0.06 

2 1.54 1.44 1.63 0.09 

6 0.94 0.73 1.17 0.07 

6 1.58 1.08 2.20 0.15 

3 1.61 1.42 1.71 0.09 

1 1.58 -- --

6 1.41 1.13 1.68 0.09 

3 1.15 0.87 1.48 0.18 

order with Stations 502 and 505 having the lowest and Station 

43 having the greatest MAMM. Age-adjusted station means 

for bass (genders combined) ranged from 4.28 MA/mm2 at 

Station 502 to 10.41 MA/mm2 at Station 43, and these differences were significant (Table 28). These data are similar 

to MAMM station means in bass from the MRB (2.2-11.2 

MA/mm2

) (Blazer and others, 2002) and RGB (approximately 

4-8 MA/mm2

) (Schmitt and others, 2004). 

The mean MAMM for carp in the CRB was 6.7 MA/ 

mm2

. MAMM values for individual fish ranged from 0.6-

22.4 MA/mm2 excluding a carp without MA data from Station 

41 (Table 27; Fig. 17). Most values (90%) were 1.2-11.8 

MA/mm2

, and Stations 42, 97, and 503 had multiple fish with 

MAMM values >15 MA/mm2

. Station means for MAMM 

ranged from 3.0 MA/mm2 at Station 41 to 10.2 MA/mm2 at 

Station 42 for carp (5.8-7.8 MA/mm2) (Table 27). MAMM 

in carp did not vary significantly among stations (Table 20). 

Carp from the MRB had similar MAMM station means (5.1-

18.3 MA/mm2

) (Blazer and others, 2002). Stations means for 

female (approximately 1-16 MA/mm2) and male (approximately 4-14 MA/mm2

) carp in the RGB were also similar to 

the CRB (Schmitt and others, 2004). 

The basin-wide mean MAMM for largescale sucker was 

6.8 MA/mm2

, and station means for MAMM in largescale 

sucker ranged from 4.9 MA/mm2 at Station 45 to 8.7 MA/mm2 

at Station 117 (Table 27). Individual MAMM in largescale 

sucker ranged from 1.8-20.0 MA/mm2 with most (90%) 

ranging from 2.9-11.7 MA/mm2

 (Fig. 18). Three fish from 
70 Environmental Contaminants and their Effects on Fish 

Table 26. Arithmetic mean of splenosomatic index (SSI; %) by station, number of samples ( n ), minimum 

(min.), maximum (max.), and standard error (SE) in the target species collected in the Columbia River Basin 

in 1997. Stations are grouped by taxon and sub-basin and ordered upstream to downstream. The maximum station mean for each taxon is shown in bold. 

Taxon and Station n Mean Min. Max. SE 

Bass 

Basin total

Upper Columbia River (UCR)

Creston, MT (117)

Snake River (SR)

Hagerman, ID (41)

Riggins, ID (43)

Lewiston, ID (42)

Ice Harbor Dam, ID (96)

Middle Columbia River (MCR)

Vernita Bridge, WA (503)

Pasco, WA (97)

Granger, WA (44)

Lower Columbia River (LCR)

Warrendale, OR (502)

Vancouver, WA (506)

Oregon City, OR (45)

Portland, OR (505)

132 0.15 0.04 1.03 0.01 

21 0.13 0.06 0.27 0.01 

16 0.15 0.06 0.29 0.02 

7 0.17 0.07 0.29 0.03 

12 0.25 0.06 0.90 0.08 

7 0.10 0.06 0.18 0.01 

5 0.11 0.09 0.15 0.01 

14 0.13 0.06 0.28 0.02 

15 0.14 0.04 0.41 0.03 

4 0.23 0.15 0.34 0.04 

1 0.11 -- -- --

22 0.12 0.07 0.22 0.01 

8 0.24 0.07 1.03 0.12 

Carp - female 

Basin total 70 0.24 0.00 0.63 0.01 

Snake River (SR) 

Hagerman, ID (41) 10 0.20 0.15 0.28 0.01 

Lewiston, ID (42) 5 0.15 0.00 0.41 0.08 

Ice Harbor Dam, ID (96) 10 0.27 0.17 0.43 0.02 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) 10 0.23 0.17 0.33 0.02 

Pasco, WA (97) 11 0.29 0.19 0.56 0.03 

Granger, WA (44) 10 0.20 0.15 0.29 0.02 

Lower Columbia River (LCR) 

Warrendale, OR (502) 10 0.26 0.15 0.34 0.02 

Oregon City, OR (45) 4 0.39 0.23 0.63 0.09 

Carp - male 

Basin total 

Snake River (SR)

Hagerman, ID (41)

Lewiston, ID (42)

Ice Harbor Dam, ID (96)

Middle Columbia River (MCR)

Vernita Bridge, WA (503)

Pasco, WA (97)

Granger, WA (44)

Lower Columbia River (LCR)

Warrendale, OR (502)

Oregon City, OR (45)

Beaver Army Terminal, OR (501)

87 0.34 0.01 0.66 0.01 

10 0.22 0.18 0.30 0.01 

12 0.30 0.01 0.64 0.04 

11 0.29 0.14 0.50 0.03 

11 0.26 0.17 0.37 0.02 

9 0.38 0.23 0.57 0.04 

10 0.36 0.14 0.51 0.03 

10 0.46 0.31 0.65 0.04 

10 0.47 0.33 0.66 0.04 

4 0.33 0.18 0.61 0.10 

Largescale sucker 

Basin total 

Upper Columbia River (UCR)

Creston, MT (117)

Northport, WA (504)

Grand Coulee, WA (98)

Lower Columbia River (LCR)

Cascade Locks, OR (46)

Warrendale, OR (502)

Vancouver, WA (506)

Oregon City, OR (45)

Portland, OR (505)

Beaver Army Terminal, OR (501)

137 0.25 0.08 0.66 0.01 

9 0.37 0.14 0.65 0.06 

19 0.36 0.15 0.66 0.03 

20 0.31 0.21 0.43 0.02 

21 0.24 0.08 0.36 0.02 

3 0.24 0.20 0.31 0.03 

21 0.18 0.08 0.28 0.01 

6 0.20 0.10 0.29 0.04 

22 0.22 0.12 0.40 0.02 

16 0.17 0.09 0.27 0.01 
S

S

SSSSS

S

SSS

SS

S

SS

S

S

SSSSS

S

SSS

SS

S

SS

0.0 

Results and Discussion 71 

2.5 CF 

Lower 

SSI-female 

Upper 

Columbia R. Snake R. 

MidColumbia R. Columbia R. 

SSI-male 

1.8 

% 

CF 

SSI 

Upper 

Columbia R. Snake R. 

MidColumbia R. 

Lower 

Columbia R. 

2.0 

1.5 

1.0 

0.5 

1.6 

1.4 

1.2 

1.0 

0.8 

0.6 

0.4 

0.6 0.2 

0.7 

0.6 0.4 

0.5 

0.2 0.4 

%

%

0.3 

0.2 

0.6 0.1 

0.0 

0.4 

117

504

9841434296

503

974446

502

506

45

505501 

Station 

Figure 15. Fish health indicators by station in female and male 0.2 largescale sucker collected in the Columbia River Basin in 1997. 

Indicators include condition factor (CF) and splenosomatic index 

(SSI). Shown for each group are points representing individual 0.0 117 5049841434296 503974446 502 50645 505 501 

fish and the mean (red horizontal line), median (black horizontal 

line), interquartile range (box), and the 10th and 90th percentiles 

(whiskers). Stations are ordered from upstream to downstream 

Station 

Figure 14. Fish health indicators by station in female and male 

carp collected in the Columbia River Basin in 1997. Indicators 

include condition factor (CF) and splenosomatic index (SSI). 

Females and males were plotted separately when analysis-ofvariance modeling determined gender was a significant factor. 

Shown for each group are points representing individual fish 

and the mean (red horizontal line), median (black horizontal line), 

interquartile range (box), and the 10th and 90th percentiles (whiskers). Stations are ordered from upstream to downstream and are 

grouped by sub-basin. See Table 3 for station descriptions. 

Stations 501 and 506 had MAMM values that >15.0 MA/mm2. 

As in the carp and bass, MAMMs did not significantly differ 

among stations for largescale sucker (Table 20). Previous 

studies on MAMM in largescale sucker have not been documented. 

and are grouped by sub-basin. See Table 3 for station descriptions. 

MEANAREA 

Gender and age influenced MEANAREA in bass, but not 

in carp or largescale sucker (Table 20); therefore, genders were 

examined separately in bass. The MEANAREA station mean 

in female bass was greatest (5,095 μm2) at Station 505, ranging from 1,675-8,735 μm2 (Table 29). All other station means 

for female bass were <4,670 μm2. Stations 43, 45, 96, 117 

and 505 had bass that had MEANAREA >5,000 μm2 (Fig. 16). 

These data did not support that MEANAREA varied significantly among stations for female bass (Table 20). Blazer and 

others (2002) found MEANAREA station means ranged from 

1,049-4,440 μm2

 for bass in the MRB. Schmitt and others 

(2004) reported similar station means (approximately 3,000-

5,000 μm2) for bass in the RGB. 

The MEANAREA station mean for male bass was greatest (5,991 μm2

) at Station 502 (n=3), ranging from 1,820-9,985 

μm2 (Table 29). All other station means for male bass ranged 
72 Environmental Contaminants and their Effects on Fish 

Table 27. Arithmetic mean of macrophage aggregate density (MAMM) by station, number of samples (n ), 

minimum (min.), maximum (max.), and standard error (SE) in the target species collected in the Columbia 

River Basin in 1997. Stations are grouped by taxon and sub-basin and ordered upstream to downstream. 

The maximum station mean for each taxon is shown in bold. MAMM are measured in MA/mm2. 

Taxon and Station n Mean Min. Max. SE 

Bass 

Basin total 124 6.30 0.59 19.41 0.32 

Upper Columbia River (UCR)

Creston, MT (117) 18 5.82 1.76 19.41

Snake River (SR)

Hagerman, ID (41) 15

Riggins, ID (43) 7

Lewiston, ID (42) 11

Ice Harbor Dam, WA (96) 7

Middle Columbia River (MCR)

Vernita Bridge, WA (503) 5

Pasco, WA (97) 14

Granger, WA (44) 13

Lower Columbia River (LCR)

Warrendale, OR (502) 4

Oregon City, OR (45) 22

Portland, OR (505) 8

0.93 

7.57 2.35 15.29 0.93 

9.50 2.94 14.12 1.65 

7.54 1.18 12.94 1.11 

7.56 4.12 10.59 0.75 

9.06 5.88 10.59 0.84 

4.45 0.59 12.35 1.17 

6.06 0.59 12.94 0.91 

4.41 1.76 7.06 1.14 

5.59 2.35 10.59 0.50 

4.12 1.76 8.24 0.87 

Carp 

Basin total 

Snake River (SR)

Hagerman, ID (41)

Lewiston, ID (42)

Ice Harbor Dam, ID (96)

Middle Columbia River (MCR)

Vernita Bridge, WA (503)

Pasco, WA (97)

Granger, WA (44)

Lower Columbia River (LCR)

Warrendale, OR (502)

Oregon City, OR (45)

Beaver Army Terminal, OR (501)

153 6.66 0.00 22.35 0.29 

17 3.04 0.00 8.24 0.47 

17 10.24 3.53 22.35 1.07 

21 6.81 4.12 11.76 0.42 

20 6.68 0.59 15.29 0.87 

20 6.91 2.35 15.88 0.65 

20 7.85 2.94 11.76 0.62 

20 5.68 1.76 12.35 0.70 

14 5.92 1.76 12.35 0.82 

4 6.32 2.35 12.35 2.14 

Largescale sucker 

Basin total 

Upper Columbia River (UCR)

Creston, MT (117)

Northport, WA (504)

Grand Coulee, WA (98)

Snake River (SR)

Riggins, ID (43)

Lower Columbia River (LCR)

Cascade Locks, OR (46)

Warrendale, OR (502)

Vancouver, WA (506)

Oregon City, OR (45)

Portland, OR (505)

Beaver Army Terminal, OR (501)

156 6.82 1.76 20.00 0.26 

9 8.69 3.53 13.53 1.12 

19 7.37 4.12 12.35 0.55 

20 5.38 2.35 10.00 0.46 

20 6.38 1.76 14.12 0.80 

21 8.24 2.94 13.53 0.57 

3 5.29 4.71 6.47 0.59 

1 7.12 1.76 17.65 3.87 

6 4.90 2.94 6.47 0.47 

22 5.51 1.76 10.00 0.41 

16 8.01 1.76 20.00 1.33 
25

12 

Results and Discussion 73 

from 2,118-4,838 μm2 with multiple stations having MEANAREA >5,000 μm2

 (Fig. 16). As in female bass, these data did 

not support that MEANAREA significantly differed among 

stations for male bass (Table 20). The mean size of aggregates 

in older male bass tended to be larger than younger males. 

The ANOVA model indicated that age was a significant 

variable for MEANAREA in bass (Table 20), thus ageadjusted values were computed (Table 28). Age-adjusted 

station geometric means for bass (genders combined) ranged 

from 2,194 μm2 at Station 97 to 4,416 μm2

 at Station 43, and 

these differences were significant (Table 28). 

The MEANAREA station mean in carp was greatest 

(5,850 μm2

) at Station 44, ranging from 2,097-11,911 μm2 

(Table 29). All other station means for carp were <4,581 μm2, 

and the basin-wide mean was 4,057 μm2. Individual carp had 

MEANAREA ranging from 0 μm2 at Station 41 to 11,911 μm2 

at Station 44 with the majority (90%) of fish having values of 

1,400–8,400 μm2 (Fig. 17). Carp from Stations 41, 42, 44, 96, 

502, and 503 had MEANAREA values >8,000 μm2; however, 

MEANAREA did not differ significantly among stations 

(Table 20). Blazer and others (2002) found MEANAREA 

station means ranged from 1,670-4,684 μm2

 in carp from the 

MRB. Station means ranged from approximately 1,500-8,000 

μm2

 in carp from the RGB (Schmitt and others, 2004). 

The MEANAREA station mean for largescale sucker was 

greatest (4,941 μm2

) at Station 502 (n=3), ranging from 3,506-

6,321 μm2 (Table 29). All other station means for largescale 

sucker ranged from 2,821-4,502 μm2, and the basin-wide 

mean was 3,580 μm2 (Fig. 18). Individual fish MEANAREA 

ranged from 716 μm2 at Station 43 to 25,066 μm2 at Station 46. 

Multiple stations had fish exceeding 5,000 μm2

; however, most 

largescale sucker (90%) had MEANAREA of 1,450-7,500 

μm2

 (Fig. 18). As in carp and bass, MEANAREA did not vary 

significantly among stations for largescale sucker (Table 20). 

There were interactions determined to be significant by the 

statistical analyses (Table 20); however, no clear trends were 

identified. 

TISSOC 

Age influenced TISSOC in bass, but not in carp or largescale sucker (Table 20); therefore, genders were examined sep10000 

Upper Lower 

 MAMM 

MEANAREA-male 

TISSOC 

MEANAREA-female 

Columbia R. Snake R. 

Mid 

Columbia R. Columbia R. 

20 

15 

10 

5 

0 

12000 

2 2 2 % μm μm #/mm 

10000 

8000 

6000 

4000 

2000 

12000 

8000 

6000 

4000 

2000 

10 

8 

6 

4 

2 

0 

117 

504

98

41

43

42

96

503

97

44

46

502

506

45

505

501 

Station 

arately in bass. Mean TISSOC was greatest (4.0%) in female 

bass from Station 43, ranging from 1.0-9.7% (Table 30), and 

all other station means for female bass were <3.6%. Stations 

42, 43, 45, 117, and 505 had female bass that had TISSOC 

>6.0% (Fig. 16), but most fish (84%) had TISSOC between 

0.4-5.0%. Age had a positive correlation with TISSOC (Table 

20), and the fish with TISSOC >6.0% were also the oldest 

(>9 years). Age was a significant factor for TISSOC in bass 

(Table 20); therefore, age-adjusted values were computed 

(Table 28). Similar to MAMM, age-adjusted station order 

was similar to non-adjusted station order for TISSOC. Ageadjusted station geometric means for bass (genders combined) 

ranged from 0.6% at Station 97 to 4.5% at Station 43, and 

Figure 16. Splenic macrophage aggregate parameters by station in female and male bass (Micropterus sp.) collected in the 

Columbia River Basin in 1997. Parameters include macrophage 

aggregate density (MAMM), macrophage aggregate area (MEANAREA), and percent of splenic tissues occupied by macrophage 

aggregates (TISSOC). Females and males were plotted separately 

when analysis-of-variance modeling determined gender was a 

significant factor. Shown for each group are points representing 

individual fish and the mean (red horizontal line), median (black 

horizontal line), interquartile range (box), and the 10th and 90th 

percentiles (whiskers). Stations are ordered from upstream to 

downstream and are grouped by sub-basin. See Table 3 for station descriptions. 
74 Environmental Contaminants and their Effects on Fish 

Table 28. Mean age-adjusted station means for splenic macrophage aggregate (MA) parameters in bass. 

Arithmetic means for MA density (MAMM) and geometric means for mean MA area (MEANAREA) and percent 

tissue occupied (TISSOC) adjusted to the basin-wide mean age (5.1 y) using analysis-of-covariance (ANCOVA) are 

shown. ANCOVA F-values and degrees-of-freedom (df) for the analyses (**P0.01; *0.01<P0.05) are also presented. 

Means followed by the same letter within each column are not significantly different (P>0.05, Fischer’s protected 

LSD). See text for description of variables and statistical procedures. 

Station MAMM (No./mm2) MEANAREA (μm) TISSOC (%) 

Creston, MT (117) 4.84 ab 2374 ab 0.97 ab 

Hagerman, ID (41) 7.86 cd 3239 bcd 2.30 cde 

Riggins, ID (43) 10.41 d 4404 d 4.45 d 

Lewiston, ID (42) 8.11 cd 4206 d 2.97 de 

Ice Harbor Dam, ID (96) 7.62 bcd 2368 abc 1.75 bcd 

Vernita Bridge, WA (503) 7.85 abcd 2698 abcd 1.88 bcde 

Pasco, WA (97) 5.00 ab 2194 a 0.63 a 

Granger, WA (44) 6.64 abc 3350 bcd 1.85 cd 

Warrendale, OR (502) 4.28 abc 4416 cd 1.67 abcde 

Oregon City, OR (45) 5.02 ab 3221 bcd 1.46 bc 

Portland Oregon, OR (505) 4.29 a 3255 abcd 1.21 abc 

ANCOVA 

Model (df 11,111) 4.50** 4.29** 6.99** 

Station (df 10,111) 3.53** 2.42** 4.18** 

Age (df 1,111) 19.99** 27.00** 38.70** 

these differences were significant (Table 28). TISSOC station 

means in bass from the MRB ranged from 0.3-3.8%, and a reference station from the study had <1.0% TISSOC (Blazer and 

others, 2002). The TISSOC station mean was approximately 

2-3% in bass in the RGB (Schmitt and others, 2004). 

The TISSOC station mean in carp was greatest (4.7%) 

at Station 44, ranging from 1.0-11.2% (Table 30). All other 

station means for female carp were <3.6%, and the basin-wide 

mean for carp was 2.7%. Stations 42, 44, 96 and 503 had fish 

that had TISSOC >6.0% (Fig. 17); however, most carp (82%) 

had TISSOC of 0.60-5.0%. As with MAMM and MEANAREA, the lowest values for TISSOC were found in carp from 

Station 41; only one fish at this station had a TISSOC value 

>2%. TISSOC did not differ significantly among stations for 

carp (Table 20). TISSOC station mean in carp was 1.2-6.4% 

in the MRB (Blazer and others, 2002) and approximately 1­

13% in the RGB (Schmitt and others, 2004). 

The TISSOC mean for largescale sucker was greatest 

(3.6%) at Station 46, ranging from 0.9-17.7% (Table 30). All 

other station means for female largescale sucker were <2.8%. 

Stations 43, 46, 501, and 504 each had one fish with TISSOC 

>6.0% (Fig. 18), but most sucker (92%) had TISSOC between 

0.50-6.0%. The station mean of Station 46 was 2.9% for largescale sucker when the maximum value (5.6%) was removed. 

As with both MAMM and MEANAREA for largescale sucker, 

CRB stations did not vary significantly in TISSOC (Table 20). 

TISSOC data for largescale sucker have not been previously 

reported. 

Fish Health Indicators: Summary 

Fish health indictors for this monitoring effort were 

selected to evaluate major organ systems and their functions 

(Schmitt and others, 2002b). The BEST program continued 

to accumulate information on the target species for comparison with various large river basins and regions throughout the 

U.S. and for the determination of “normal” ranges for many of 

these indicators. The fish health indicators can be affected by 

various factors (that is, age, gender, reproductive status, geographic location) other than contaminants, but were selected to 

reflect overall organismal health of the fish and their populations. 

Species (or genera) were analyzed separately in attempt 

to eliminate as many confounding factors as possible. Potential effects of gender and age on comparisons among stations 

were evaluated statistically. Analysis of the data indicated no 

effect of gender on external lesions, MAMM, TISSOC, HAI in 

carp, bass, and largescale sucker, CF and MEANAREA in carp 

and largescale sucker, and SSI in bass and largescale sucker. 

Of the remaining indicators, CF and MEANAREA in bass and 

SSI in carp differed between genders; therefore, males and 

females were evaluated separately for these indicators. HSI 

in bass was analyzed by gender due to the role of the liver in 

vitellogenesis (Scott and Pankhurst, 1992). Age is known 

to significantly influence MA density, at least in some fishes 

(Brown and George, 1985) including largemouth bass (Blazer 

and others, 1987). For these reasons age was considered in the 

statistical model for station comparisons of these parameters. 

Most of the endpoints measured in CRB fish were limited 

to the target species (that is, bass, carp, and largescale sucker) 

to remain consistent with other portions of the study. However, some endpoints such has external lesions were measured 
S

S

SS

S

SS

S

SSS

S

S

S

SS

25 

12 

Results and Discussion 75 

estuarine and freshwater systems (Fournie and others, 1996; MAMM 

MEANAREA 

Sanderson and van den Berg, 1999). Numerous studies have 20 correlated the high prevalence of external anomalies with 

exposure to anthropogenic stressors (Fournie and others, 1996; 15 McCain and others, 1992; Sindermann, 1979). Fin erosion 

(Cross, 1985; Lindesjoo and Thulin, 1990; Murchelano and 10 Ziskowski, 1982; Reash and Berra, 1989), skin and liver 

tumors (Baumann and others, 1991; Malins and others, 1988; 5 Vogelbein and others, 1990), and skeletal deformities (Bengtsson, 1979; Bengtsson and others, 1985; Mehrle and others, 0 1982) are the anomalies most commonly associated with 14000 

μm 2 #/mm2 % 

degraded environments. Other lesions including eye anomalies and skin ulcerations have also been suggested to be results 

of anthropogenic stress (Hargis and Zwerner, 1988). However, 

most external lesions identified in CRB fish were frayed or 

hemorrhagic fins which are not necessarily associated with 

exposure to contaminants. 

The overall proportion of fish with external lesions was 

0.74 (of a total of 560 fish examined). Leonard and Orth 

(1986) found that the proportion of fish with abnormalities 

in small cool water streams was 0.080-0.344 in “degraded” 

streams and 0-0.01 for streams only mildly affected. In a 

12000 

10000 

8000 

6000 

4000 

2000 

0 

study of streams in Ohio, proportions ranged from 0.0004- TISSOC 

Upper 

Columbia R. Snake R. 

MidColumbia R. 

Lower 

Columbia R. 

0.081 for DELT (deformities, erosions, lesions, tumors) 10 anomalies (Sanderson and van den Berg, 1999). Background 

prevalence of gross abnormalities in estuarine fishes was 8 

estimated to be 0.5% in the mid-Atlantic and 0.88% in the 

Louisiana Providence (Fournie and others, 1996). Caution 

must be exercised when comparing the CRB results with those 

6 

4 of other studies and even in comparing stations with in study 

for a number of reasons. First, errors in proportion of anoma­ 2 

lous fish can result from biased or differential examination of 

0 fish, species composition, habitat, and other factors unrelated 

to environmental degradation are widely recognized (Leonard and Orth, 1986). In the present study, this error could be 

compounded by the fact that multiple individuals from several 

117504

98

41

43

4296

503

974446

502

506

45

505

501 

Station 

offices and organizations were involved in assessing external 

anomalies. A second confounding factor in comparing the 

results of various studies is the different anomalies that are 

considered. All external in the IBI fish health metric signs 

of disease, parasites, and anomalies are considered (Karr, 

1981). In contrast, Fournie and others (1996) examined only 

the eyes, body surface, fins, and branchial chamber, noting 

discolorations, raised scales, exophthalmia, white or black 

spots, ulcers, fin erosion, visible tumors and parasites. Sanders and others (1999) noted only deformities of the fins, head, 

vertebrae, barbels, and opercles including erosion of the fins, 

opercles, barbels, and lesions (open sores, ulcerations), but not 

external parasites. Abnormalities of the body surface, eyes, 

opercles, and fins, including deformities and parasites were 

evaluated in this 1997 study. 

External lesions were identified on 69% of the 134 bass 

from 12 stations, on 83% of the 157 carp from nine stations, 

and on 78% of the 160 largescale sucker from nine stations 

from fish collected from the CRB in 1997. A greater proportion of carp and largescale sucker had external lesions at 12 

Figure 17. Splenic macrophage aggregate parameters by station 

in female and male carp collected in the Columbia River Basin 

in 1997. Parameters include macrophage aggregate density 

(MAMM), macrophage aggregate area (MEANAREA), and percent 

of splenic tissues occupied by macrophage aggregates (TISSOC). 

Females and males were plotted separately when analysis-ofvariance modeling determined gender was a significant factor. 

Shown for each group are points representing individual fish 

and the mean (red horizontal line), median (black horizontal line), 

interquartile range (box), and the 10th and 90th percentiles (whiskers). Stations are ordered from upstream to downstream and are 

grouped by sub-basin. See Table 3 for station descriptions. 

in all species. The proportion of fish with disease or anomalies, irrespective of species, is used as a health metric in the 

Index of Biotic Integrity (IBI) (Karr, 1981; Leonard and Orth, 

1986) and the EIB, estuarine biotic integrity index (Deegan 

and others, 1997). A number of recent studies have compared 

sites using external anomalies of all fish species collected in 
—Continued

76 Environmental Contaminants and their Effects on Fish 

Table 29. Arithmetic mean of macrophage aggregate area (MEANAREA) by station, number of 

samples (n ), minimum (min.), maximum (max.), and standard error (SE) in the target species collected 

in the Columbia River Basin in 1997. Stations are grouped by taxon and sub-basin and ordered 

upstream to downstream. The maximum station mean for each taxon is shown in bold. MEANAREA is 

measured in μm2

. 

Taxon and Station n Mean Min. Max. SE 

Bass - female 

Basin total 70 3519 700 9886 220 

Upper Columbia River (UCR) 

Creston, MT (117) 9 3995 2144 5323 358 

Snake River (SR) 

Hagerman, ID (41) 8 3191 2333 4804 341 

Riggins, ID (43) 3 4670 2004 7192 1499 

Lewiston, ID (42) 4 3644 744 4850 974 

Ice Harbor Dam, ID (96) 4 3067 1009 6300 1138 

Middle Columbia River (MCR) 

Vernita Bridge, WA (503) 3 3457 2318 4296 590 

Pasco, WA (97) 8 2171 700 4618 437 

Granger, WA (44) 9 2872 822 4258 402 

Lower Columbia River (LCR) 

Warrendale, OR (502) 1 3880 -- -- --

Oregon City, OR (45) 15 3955 1545 9886 562 

Portland, OR (505) 5 5095 1675 8735 1458 

Bass - male 

Basin total

Upper Columbia River (UCR)

Creston, MT (117)

Snake River (SR)

Hagerman, ID (41)

Riggins, ID (43)

Lewiston, ID (42)

Ice Harbor Dam, WA (96)

Middle Columbia River (MCR)

Vernita Bridge, WA (503)

Pasco, WA (97)

Granger, WA (44)

Lower Columbia River (LCR)

Warrendale, OR (502)

Oregon City, OR (45)

Portland, OR (505)

52 3521 823 10481 276 

8 2584 823 5379 609 

7 3235 1957 5565 449 

4 3902 1839 6383 1036 

6 4713 3127 6306 452 

3 2246 1783 3157 456 

2 3381 3035 3727 346 

6 2362 851 3460 421 

4 4463 3071 6549 760 

3 4991 1820 9985 2527 

6 4838 2567 10481 1222 

3 2118 1594 3146 514 

Carp 

Basin total 

Snake River (SR)

Hagerman, ID (41)

Lewiston, ID (42)

Ice Harbor Dam, ID (96)

Middle Columbia River (MCR)

Vernita Bridge, WA (503)

Pasco, WA (97)

Granger, WA (44)

Lower Columbia River (LCR)

Warrendale, OR (502)

Oregon City, OR (45)

Beaver Army Terminal, OR (501)

153 4057 0 11911 188 

17 2690 0 8895 475 

17 3946 1240 10665 564 

21 4581 1861 10935 482 

20 4079 799 8344 485 

20 3437 1708 5902 303 

20 5850 2097 11911 591 

20 3788 715 11716 628 

14 4021 1236 7866 550 

4 3074 1763 4116 489 
Results and Discussion 77 

Table 29. Arithmetic mean of macrophage aggregate area (MEANAREA) by station, number of 

samples (n ), minimum (min.), maximum (max.), and standard error (SE) in the target species collected 

in the Columbia River Basin in 1997. Stations are grouped by taxon and sub-basin and ordered 

upstream to downstream. The maximum station mean for each taxon is shown in bold. MEANAREA is 

measured in μm2

.—Continued 

Taxon and Station n Mean Min. Max. SE 

Largescale sucker 

Basin total 154 3580 716 25066 206 

Upper Columbia River (UCR) 

Creston, MT (117) 9 2821 1535 3935 219 

Northport, WA (504) 19 3934 1039 7964 448 

Grand Coulee, WA (98) 20 3728 1671 7504 382 

Snake River (SR) 

Riggins, ID (43) 20 3210 716 8238 391 

Lower Columbia River (LCR) 

Cascade Locks, OR (46) 20 4502 2000 25066 1106 

Warrendale, OR (502) 3 4941 3506 6321 813 

Vancouver, WA (506) 20 3004 1431 8778 378 

Oregon City, OR (45) 6 4199 1000 8461 1100 

Portland, OR (505) 21 3315 820 9660 426 

Beaver Army Terminal, OR (501) 16 3289 1237 13868 738 

of the 16 stations where bass and carp or largescale sucker 

were collected. Fournie and others (1996) reported a higher 

prevalence of external lesions on demersal fishes compared to 

pelagic fishes from the Gulf of Mexico. These findings were 

also similar to the finding of Sanders and others (1999), who 

used external anomalies to characterize biological integrity 

of seven Ohio streams. Of the 2,624 carp they collected, 

28.5% had external anomalies versus only 2.9% of 5,037 bass 

(largemouth, spotted, and smallmouth). Schmitt and others 

(2002) found that 28% of bass and 20% of carp collected from 

the MRB had external lesions. Similar proportions of external 

lesions were reported in bass (27%) and carp (29%) in the 

RGB (Schmitt and others, 2004). In the CRB, high proportions of bass with external lesions (>75%) were collected from 

Station 41 in the SR, Station 44 in the MCR, and Stations 45, 

502, 505, and 506 in the LCR. However, at Stations 502 and 

506 few bass (n<10) were collected. Carp with high proportion of external lesions (>75%) were collected from Stations 

41, 42, and 96 of the SR, Stations 44 and 503 of the MCR, 

and Stations 45, 501, and 502 of the LCR. Largescale sucker 

with proportions of external lesions >75% were collected from 

Station 504 of the UCR and Stations 45, 46, 501, 505, and 506 

of the LCR. High percentages of external lesions for bass and 

carp or largescale sucker were found at Stations 41, 44, 45, 

502, 505, and 506. Histopathological examinations of external 

lesions collected by field personnel are summarized in the 

Geographical Summary section. 

The HAI, which is also an assessment of grossly visible lesions, is more comprehensive than the incidence of 

external lesions accounting for both external and internal 

abnormalities. The HAI has been used to assess largemouth 

bass populations, particularly in the Tennessee Valley Authority (TVA) reservoirs in the Southeast. The mean HAI for all 

TVA reservoirs was 62, the “healthiest” reservoir average 17, 

and the worst had a mean of 79 in a survey of 28 reservoirs 

(Adams and others, 1993). The HAI of largemouth bass from 

PCB-contaminated Hartwell Reservoir ranged from 42 at the 

reference site to 64 at an intermediate site, and, 74 at the most 

contaminated site. Station mean HAI scores for largemouth 

bass averaged 42 and ranged from 18 at minimally impacted 

sites to 94 at sites with combined stressors from the Catawba 

River system influenced by industrial and sewage effluents 

(Coughlin and others, 1996). Therefore, Coughlan and others 

(1996) suggested that only bass between 250 and 459 mm 

(TL) be included, because a positive linear relation between 

fish weight and HAI score was noted. A number of stations 

in the CRB had individual bass >450 mm. To our knowledge, 

this methodology has had limited use with carp and largescale 

sucker. Common carp from the MRB had individual HAI 

scores ranging from 0-160, with most sub-basin means having 

scores <40 (Blazer and others, 2002). Most (72%) carp and 

bass from the RGB had HAI scores between 0-60 (Schmitt 

and others, 2004). White sucker from the upper MRB had 

individual HAI scores ranging from 0-90 (BEST Program, 

unpublished data). The Bi-State Water Quality Program 

conducted a fish health study in the lower CRB in 1994 (Tetra 

Tech Inc., 1996). Largescale sucker had generally low HAI 

scores ranging from 0-60 for individual fish. HAI scores in 

individual fish from the lower CRB collected in 1997 ranged 

from 0-130; station means throughout the basin did not exceed 

63. None of the station means were <20 for any of the target 

species. Only bass from three CRB stations (Stations 41, 44, 

and 45) exceeded the “worst” HAI station mean of 79 in the 

TVA study (Adams and others, 1993), and only bass from 

Station 41 exceeded the highest HAI station mean of 94 in the 

Catawba study (Coughlan and others, 1996). 
S

S

SSSSS

S

SSS

SS

S

SS

30000 

0 

20 

78 Environmental Contaminants and their Effects on Fish 

25 ent has been linked to elevated CF (Adams and others, 1992; MAMM 

McMaster and others, 1991), whereas diminished CF had 

been observed after exposure to contaminants such as metals 

and petroleum (Kiceniuk and Khan, 1987; Miller and others, 

1992; Munkittrick and Dixon, 1988). Condition factor can 

20 

15 

also vary among locations within a species (Doyon and others, 

1988; Fisher and others, 1996). A review by Carlander (1969) 

determined mean CF to range from 1.2 to >2.0 in the U.S. 

A similar review of largemouth and smallmouth bass found 

mean CFs of 1.1-1.9 and 1.2-1.9, respectively (Carlander, 

1977). Mean CF for bass had greater ranges (1.3-2.1 for 

2 

% μm 2 #/mm 

10 

5 

females and 1.3-1.8 for males) than other species. Bass with MEANAREA 

TISSOC 

Upper 

Columbia R. Snake R. 

MidColumbia R. 

Lower 

Columbia R. 

CF >2.0 were found at Stations 97, 117, and 502; CF of <1.0 25000 in individual fish were found in males at Stations 43, 97, and 

117. The range of CF station means for carp in the CRB was 20000 

1.1-1.4. Individual fish with CFs <1.0 were found in the MCR 

15000 at Stations 96, 97, and 503; no station was notable for low CF 

in carp. Largescale sucker had the lowest CF ranging from 10000 0.9-1.2. Individual largescale sucker from Station 505 had the 

three lowest CF calculated. 

The HSI may vary with season (Beamish and others, 

5000 

0 1996; Delahunty and de Vlaming, 1980), temperature (Fine 

and others, 1996), and nutrition (Daniels and Robinson, 1986; 

Foster and others, 1993) as well as gender and changes in 

16 gonadal status (Fabacher and Baumann, 1985; Förlin and 

Haux, 1990; Grady and others, 1992). It is also the organoso12 matic index for which changes are most often associated with 

contaminant exposure (Adams and McLean, 1985). Increased 

8 HSI had been reported with exposure of feral fish to organic 

contaminants, most often PAHs and PCBs, whereas laboratory exposures of fish to metals, crude oil, certain pesticides, 

and bleached kraft mill effluent have resulted in HSI decreases 

4 

(Schmitt and Dethloff, 2000). However, two studies found 

HSI increased in largemouth bass after exposure to bleached/ 

117

504

unbleached kraft mill effluents (Sepúlveda and others, 2001, 

984143

42

96

503

97

4446

502506

45

505501 

2003). A comparative range for normal liver weight in fish 

is 1-3% of body weight, with relative weights >2% being 

uncommon (Gingerich, 1982). In the CRB, only bass were 

included in HSI calculations due to the diffuse nature of carp 

and sucker livers. For female bass, station means ranged from 

1.0-2.3% with Stations 45 (in the Willamette River of the 

LCR) and 503 (in the MCR) having several individuals with 

HSI >2.0%. 

The SSI is measured to determine changes in the relative size of the spleen, a primary hematopoietic organ in fish. 

The SSI can differ among species, gender, and location and 

can change over age, size, gonadal development, and season 

(Krykhtin, 1976; Ruklov, 1979; White and Fletcher, 1985). 

Studies have also documented changes in relative spleen size 

with exposure to chemical contaminants. Decreased SSI had 

been reported in fish exposed to organic contaminants alone or 

in combination with metals, but increased SSI has rarely been 

documented with contaminant exposure (Schmitt and Dethloff, 

2000). An increase in SSI is considered indicative of disease 

or immune problems (Goede and Barton, 1990). Capture and 

holding stress have been reported to alter SSI and HSI in field 

Station 

Figure 18. Splenic macrophage aggregate parameters by station 

in female and male largescale sucker collected in the Columbia 

River Basin in 1997. Parameters include macrophage aggregate 

density (MAMM), macrophage aggregate area (MEANAREA), 

and percent of splenic tissues occupied by macrophage aggregates (TISSOC). Females and males were plotted separately 

when analysis-of-variance modeling determined gender was a 

significant factor. Shown for each group are points representing 

individual fish and the mean (red horizontal line), median (black 

horizontal line), interquartile range (box), and the 10th and 90th 

percentiles (whiskers). Stations are ordered from upstream to 

downstream and are grouped by sub-basin. See Table 3 for station descriptions. 

Condition factor may indicate changes at the organism 

level and is directly affected by nutrition (Tyler and Dunn, 

1976), and also by season, sexual maturation, and disease 

(Adams and others; Denton and Yousef, 1976; 1982; Möller, 

1985). Exposure to contaminants such as pulp mill efflu­
Results and Discussion 79 

Table 30. Arithmetic mean of percent of splenic tissue occupied by macrophage aggregates (TISSOC) 

by station, number of samples (n ), minimum (min.), maximum (max.), and standard error (SE) in the target 

species collected in the Columbia River Basin in 1997. Stations are grouped by taxon and sub-basin 

and ordered upstream to downstream. The maximum station mean for each taxon is shown in bold. 

TISSOC is measured as a %. 

Taxon and Station n Mean Min. Max. SE 

Bass 

Basin total

Upper Columbia River (UCR)

Creston, MT (117)

Snake River (SR)

Hagerman, ID (41)

Riggins, ID (43)

Lewiston, ID (42)

Ice Harbor Dam, WA (96)

Middle Columbia River (MCR)

Vernita Bridge, WA (503)

Pasco, WA (97)

Granger, WA (44)

Lower Columbia River (LCR)

Warrendale, OR (502)

Oregon City, OR (45)

Portland, OR (505)

124 2.40 0.08 9.73 0.18 

18 1.10 0.20 9.06 0.52 

15 2.51 0.55 5.32 0.37 

7 4.00 0.97 9.73 1.11 

11 3.55 0.09 6.12 0.64 

7 2.17 0.71 5.56 0.64 

4 3.06 2.19 3.98 0.41 

14 1.09 0.08 3.97 0.37 

13 2.00 0.18 4.74 0.39 

4 2.31 0.56 5.28 1.11 

22 2.49 0.42 7.40 0.43 

8 2.18 0.28 6.68 0.98 

Carp 

Basin total 

Snake River (SR)

Hagerman, ID (41)

Lewiston, ID (42)

Ice Harbor Dam, ID (96)

Middle Columbia River (MCR)

Vernita Bridge, WA (503)

Pasco, WA (97)

Granger, WA (44)

Lower Columbia River (LCR)

Warrendale, OR (502)

Oregon City, OR (45)

Beaver Army Terminal, OR (501)

153 2.73 0.00 11.21 0.16 

17 0.94 0.00 4.71 0.26 

17 3.58 1.12 6.90 0.37 

21 3.10 0.88 6.29 0.33 

20 3.00 0.07 7.53 0.48 

20 2.32 0.54 5.08 0.26 

20 4.65 1.04 11.21 0.61 

20 1.92 0.34 5.13 0.32 

14 2.08 0.66 4.75 0.30 

4 2.05 0.41 3.81 0.72 

Largescale sucker 

Basin total 

Upper Columbia River (UCR)

Creston, MT (117)

Northport, WA (504)

Grand Coulee, WA (98)

Snake River (SR)

Riggins, ID (43)

Lower Columbia River (LCR)

Cascade Locks, OR (46)

Warrendale, OR (502)

Vancouver, WA (506)

Oregon City, OR (45)

Portland, OR (505)

Beaver Army Terminal, OR (501)

156 2.35 0.06 17.70 0.15 

9 2.60 0.54 5.09 0.47 

19 2.82 0.67 6.23 0.33 

20 1.90 0.62 3.90 0.20 

20 2.06 0.13 7.06 0.35 

21 3.57 0.86 17.70 0.76 

3 2.53 2.27 2.97 0.22 

20 1.95 0.06 5.10 0.33 

6 2.02 0.25 4.48 0.67 

22 1.81 0.14 4.54 0.23 

16 2.34 0.22 6.88 0.45 
80 Environmental Contaminants and their Effects on Fish 

studies (Schmitt and Dethloff, 2000). 

Stations in the CRB are described as having high or low 

SSI relative to one another because “normal” ranges are not 

available for bass, carp, or largescale sucker. For bass, SSI 

ranged from 0.1-0.3% with Stations 96, 503, and 506 having 

the lowest stations means. Stations 42, 502, and 505 had the 

highest mean SSI for bass. Three individual bass from Stations 42 and 505 had SSI values >0.6%. There were multiple 

bass with low SSI values at multiple stations. For carp, mean 

station SSI ranged from 0.2-0.4% in females and 0.2-0.5% in 

males. Low SSI station means in female carp and low individual SSI values occurred in both female and male carp from 

Station 42 in the SR. The greatest SSI values (>0.5%) in carp 

occurred in the LCR at multiple stations (Stations 45, 501, 

502). SSI in largescale sucker ranged from 0.2-0.4%. Individual fish from stations in the UCR had SSI values >0.5%, 

whereas fish from the LCR had SSI values <0.1%. 

Laboratory investigations and field studies in which fish 

were collected from specific contaminated sites have generally indicated increases in MA parameters relative to reference 

sites or groups (Blazer and others, 1994; 1997; Wolke, 1992). 

MA parameters have been used as bioindicators in other 

programs such as the USEPA’s Environmental Monitoring and 

Assessment Program (EMAP) of estuaries (Fournie and others, 2001; Summers and others, 1993) and National Oceanic 

and Atmospheric Administration (NOAA) Status and Trends 

programs (Chang and others, 1998). Some studies have used 

splenic MAs whereas others have utilized hepatic MAs. Most 

of these studies have been performed in marine or estuarine 

environments. Most previous studies have only evaluated MA 

density, and even for this parameter, regional baseline information does not exist to establish a “normal” value for any 

species. To our knowledge, there have not been any studies 

evaluating carp, bass, or largescale sucker MA and potential 

effects of contaminant exposure. One study did report an 

increase in MA in largemouth bass exposed to thermal effluent 

from a nuclear power plant (Blazer and others, 1987). Numerous studies have reported factors that can affect MAs in other 

species. The factors include size, nutritional status (Agius, 

1979; 1980; Agius and Roberts, 1981; Wolke and others, 

1985), age (Blazer and others, 1987; Brown and George, 1985; 

Couillard and Hodson, 1996), and exposure time (many as 

reported in Schmitt and Dethloff, 2000). 

MA parameters were also evaluated in the CRB in 

1997. Station means for MA density in the CRB were 4.1-

9.5 MA/mm2

 in bass, 3.0-10.2 MA/mm2 in carp, and 4.9-8.5 

MA/mm2 in largescale sucker. Statistical analyses of the data 

suggested there was not a consistent relationship between age 

and MA density in the target species from the CRB. Fournie 

and others (2001) suggested than splenic MA densities of >40 

MA/mm2 in at least one fish from a site were correlated with 

hypoxic stress or high levels of sediment contamination using 

data collected in the EMAP-Estuaries program for a variety of 

estuarine fishes and irrespective of age. There is insufficient 

data to know if this is a reasonable reference number for freshwater fishes or how MA may be correlated with body burdens 

of various contaminants. However, fish collected from the 

CRB did not exceed 40 MA/mm2

. Only Station 42 in the SR 

had an individual carp with >20 MA/mm2; all individual bass 

and largescale sucker were <20 MA/mm2. 

Reproductive Biomarkers 

Gonadal Histopathology 

Gonadal histopathology and gonadosomatic index (GSI) 

are reproductive indicators that provide structural information 

about gonadal health and maturational stage. Gonadal histopathology can be affected by season, age, gender, and pollutants (Schmitt and Dethloff, 2000). Reproductive biomarkers 

were evaluated relative to the stage of gonad development of 

fish from the CRB. The gender and developmental stage of 

bass and carp influenced the reproductive biomarkers (Table 

20). Therefore, the data for male and female bass and carp 

were examined separately, so as not to confound the potential 

effects other variables may have on the reproductive biomarkers with the effects caused by gender and stage of gonad 

development. Due to the relatively small size of the data set, 

statistical methods (for example, log transformations) were 

not used to adjust station means for stage although stage was 

found to be an important variable for determining GSI and vtg 

for certain species. Instead, patterns or trends are discussed in 

the data in relation to fish reproductive stage at each station. 

Stages of reproductive development are described in Figures 

19 and 20. 

Female Bass 

Examining the stage of gonad development is critical for 

the interpretation of reproductive biomarkers. Female bass 

were in stages 0-3 with the majority (55%) identified as stage 

1 (Fig. 21). Stage-2 and -3 ovaries represented 22% and 18%, 

respectively, of female bass collected, while 4% of female bass 

were identified as stage 0. Fish in stage 0 were present at Stations 42, 44, and 97 (Fig. 22). Females in stage 1 were found 

at all stations where bass were collected with the exception of 

Station 506; stage-2 and stage-3 females were each collected 

from five stations. Stage distributions differed among stations 

(Fig. 22). 

GSI was greatest (2.9%) in female bass at Station 45, 

ranging from 0.5-7.2% (Table 31), and other station means 

were <2.4%. Only Station 45 had fish with GSI >4% (Fig. 

23). Female bass GSI did not vary significantly among 

stations although GSI and stage had a significant correlation (Table 20). Stage-3 female bass had the greatest GSI 

values. GSI station means in female bass were <2% in the 

MRB (McDonald and others, 2002) and 0.6-0.9% in the RGB 

(Schmitt and others, 2004). Other laboratory studies deter­
Results and Discussion 81 

Figure 19. Gonadal stages in female fish species. A. Stage-1 (immature) ovary containing only previtellogenic oocytes. B. Stage-2 

(early vitellogenic) containing cortical alveolar (a) and previtellogenic oocytes. C. Early stage-3 ovary containing cortical alveolar (a) 

and more advanced oocytes (b). Yolk vacuoles are being pushed to the periphery, and yolk globules are filling the central portion of the 

oocyte. D. Late stage-3 ovary with enlarged oocytes. A thin layer of yolk vacuoles line the periphery, yolk globules fill the cytoplasm, 

and the chorion (arrow) is thickened. E. Stage-4 (late vitellogenic) ovary containing enlarged oocytes and condensed yolk globules. F. 

Stage-5 (spent) ovary containing post-ovulatory follicles (shown at the ends of the arrow). H&E stain (X 165). 
82 Environmental Contaminants and their Effects on Fish 

Figure 20. Gonadal stages in male fish species. A. Stage-1 (early spermatogenic) testes can contain all stages of spermatogenesis, 

spermatogonia (arrows), spermatocytes (a), spermatids (b) and spermatozoa (c). H&E stain (X 824). B. Stage-1 testes in which spermatocytes and spermatids predominate. H&E (X 412). C. Stage-2 (mid-spermatogenic) testes containing approximately equal numbers 

of spermatocytes, spermatids and spermatozoa. H&E (X 412). D. Stage-3 (late spermatogenic) testes containing primarily mature spermatozoa. H&E (X 412). 

mined GSI in female largemouth bass to range from 2.7-4.0% 

(Sepúlveda and others, 2001; 2003). 

The gender and developmental stage of bass influenced 

concentrations of vtg (Table 20), resulting in females and 

males being examined separately. Mean vtg in female bass 

was greatest (14.2 mg/mL) at Station 503, ranging from 12.1-

17.7 mg/mL (Table 32). Station 503 consistently had female 

bass with greater concentrations of vtg. Other station means 

for female bass ranged from 0.1-7.0 mg/mL, and concentrations of vtg did not vary significantly among stations. Most 

female bass (75%) had concentrations of vtg between 0.2-3.0 

mg/mL (Fig. 23) which were similar to concentrations of vtg 

found by several other studies (Schmitt and others, 2004; 

Sepúlveda and others, 2001; 2003). Female bass from Stations 

43, 44, 45, 96, 97, and 503 had concentrations of vtg >10.0 

mg/mL, although a stage pattern was not apparent for these 

fish. In general, stage-2 and-3 fish tended to have greater concentrations of vtg than stage-0 and -1. McDonald and others 

(2002) determined similar stage patterns and concentrations 

of vtg in female bass from the MRB. Collection date did not 

appear to influence concentrations of vtg, since low concentrations of vtg were collected on the same date as high concentrations from female bass at the same station. 

Mean percent atresia in bass was similar among stations in the CRB. Mean percent atresia was greatest (12%) in 

female bass at Station 502 (n=1) (Table 33), and all other station means were <7.1%. With the exception of one individual 

fish from Station 41, all values were <15% (Fig. 23). Overall, 

station means did not significantly differ for percent atresia, 

but female bass at Stations 41, 502, and 505 generally had 

higher values (Fig. 23). Atresia station means in bass ranged 

from approximately 0-6% in the MRB (McDonald and others, 
Results and Discussion 83 

% 

100

90

80

70

60

50

Bass 

Stage 5 

Stage 3 

Stage 2 

Stage 1 

Stage 0 

M F M F M

 (n=69) 

F

20 

1 

11 

26 

4 

41 

16 

13 

34 

51 

1 

10 

58 

1 

2 

2 

65 

21 

44 

22 

1 

 (n=58) (n=74) (n=85) (n=70) 

Common Carp 

 (n=88) 

Largescale Sucker 

40

30

20

10

0 

Species 

Figure 21. Gonadal stage proportions by taxon and gender in bass, carp, and largescale sucker collected in the Columbia River Basin in 

1997. Sample sizes for each stage and gender by taxon are located next to the boxes within the figure. 

2002) and 0-30% in the RGB (Schmitt and others, 2004), and 

a reference station from the MRB had a mean percent atresia 

of about 3%. Fish from Stations 41, 42, 502, 503, and 505 had 

mean percent atresia >3%. 

Male Bass 

Developmental stage of gonads in male bass differed 

among stations, similar to female bass (Table 20). Male bass 

were in stages 0-3, and stage-2 testes represented the gonadal 

stage 45% of male bass collected (Fig. 21). No single stage 

was present at all stations where male bass were collected, 

while stage-2 fishes were present at all stations with the exceptions of Stations 502 and 503 (Fig. 23). 

Intersex gonads were seen only in male bass in the CRB. 

Five (smallmouth bass) of 56 male bass had evidence of an 

ovotestes. Three of seven male bass collected from Station 42 

had ovotestis in stage 0, 1, and 2. Two of three male bass from 

Station 502 had ovotestis in stage 3. Therefore, a relatively 

high percentage of male bass from these two stations had ovotestes. Other endpoints were examined to investigate possible 

correlations to these ovotestes males. Age or size relationship 

was not found at either station. However, ovotestes males 

from Station 42 had the greatest HSI, GSI, and MA parameters 

from that station, and ovotestes males from Station 502 had 

the greatest HSI and MEANAREA from that station. Male 

bass from Station 42 had high concentrations of PCBs and had 

the greatest concentration of trans-nonachlor for combined 

composite samples while male bass from Station 502 had 

high concentrations of As. The only male at Station 42 with 

a detectable vtg concentration (0.011 mg/mL) was identified 

as ovotestes and had the greatest HSI (1.57%) of all male bass 

from that station. 

GSI in male bass were similar among CRB stations. GSI 

in male bass was greatest (0.9%) at Stations 96 and 505 (Table 

31), while other station means ranged from 0.2-0.8%. Only 

Stations 96 and 97 had fish with GSI >1.0% (Fig. 23). Male 

bass GSI did not vary significantly among stations (Table 20), 

and GSI and stage were not correlated. GSI station means 

in male bass ranged from approximately 0.1-0.7% in the 

MRB (McDonald and others, 2002) and 0.2-0.4% in the RGB 

(Schmitt and others, 2004). GSI in male largemouth bass from 

two laboratory studies ranged from <0.5-0.95% (Sepúlveda 

and others, 2001; 2003). 

Concentrations of vtg were also measured in male bass. 

Most male bass (90%) had concentrations of vtg <LOD (0.002 

mg/mL) (Fig. 23). Stations 42, 43, 96, 97, and 117 each 
84 Environmental Contaminants and their Effects on Fish 

100 

80 

60 

M F M F M F M F M F M F M F M F M F M M F M F 0 

20 

40 

/97 /97 /97 /

6 

3 

14 

6 

1 

1 

3 

7 

3 

2 

43 

32 

1 

1 

1 

3 

2 

3 

3 

96 

21 

1 

1 

2 

/ / 97 /97 

2 3 6 1 

7 

1 

44 /97 

11 

2 

3 

3 

2 

3 

4/

31 1

45 

45 

2 

4 

6 

505 

51 

2 

% 

Figure 22. Gonadal stage proportions by station in female and male bass (Micropterus sp.) collected in the Columbia River Basin in 1997. 

Station sample sizes for each stage are located in the boxes within the figure. 

Stations are ordered from upstream to downstream and are grouped by sub-basin. 

Station 

Stage 3 

Stage 2 

Stage 1 

Stage 0 

117 41 

Upper 

Columbia R. Snake R. Mid-Columbia R. Lower Columbia R. 

9/24-25 10/31-11/1 10/2 9/30 97 42 10/10-11/97 503 10 13-14 97 10/8-9 10/15-16 502 10/25-26/97 506 

2/98 11/21-24/97 11/14-17/97 

The collection dates for each station are located below 

the station number. See Table 3 for station descriptions. 

had one male bass with concentrations of vtg >0.01 mg/mL. 

Concentrations >0.01 mg/mL indicate an estrogenic response 

in these male bass, but should not be considered a general 

problem at any of these stations since these concentrations 

were limited to individual fish. The maximum concentration 

of vtg in male bass was 0.67 mg/mL at Station 97, a concentration indicative of exposure to endocrine disruption (Fig. 

23). These data are similar to concentrations found in male 

bass from the MRB (McDonald and others, 2002) and RGB 

(Schmitt and others, 2004). Several laboratory studies determined male largemouth bass concentrations of vtg to range 

from <LOD (0.001 mg/mL) to 0.32 mg/mL (Sepúlveda and 

others, 2001; 2003). 

Two bass with no preserved gonad were collected from 

Stations 42 and 45; concentrations of vtg were 0.04 mg/mL 

and <LOD (0.002 mg/mL), respectively. 

Female Carp 

Reproductive stage of gonads in female carp differed 

among stations (Table 20). Most female carp (83%) were 

identified as stage 2. Stage-0 and -3 each represented 1.5%, 

and stage-1 ovaries represented 14% (Fig. 21). Females in 

stage 2 were found at all stations where carp were collected 

(Fig. 24). Stage-0 females were collected from Station 41, 

stage-1 females were collected from Stations 41, 44, and 503, 

and stage-3 females were collected from Stations 501 and 502. 

GSI in female carp varied among stations in the CRB. 

GSI was greatest (14.4%) in female carp at Station 502, ranging from 8.2-20.5% (Table 31). Other station means were 

>10.0% for female carp with the exception of Station 41. 

Stations 44, 45, 502 and 503 had fish with GSI >16%, but the 

majority (86%) of female carp had a GSI <15% (Fig. 25). GSI 

in female carp varied significantly among stations with an 

increasing trend upstream to downstream (Fig. 25; Table 20). 

GSI station means in female carp ranged from approximately 

1-18% in the MRB (McDonald and others, 2002) and 5-20% 

in the RGB (Schmitt and others, 2004). 

The gender and developmental stage of carp influenced 

concentrations of vtg (Table 20), resulting in females and 

males being examined separately. Mean vtg in female carp 

was greatest (3.9 mg/mL) at Station 42, ranging from 1.4-7.4 

mg/mL (Table 32). All other station means for female carp 

were <2.2 mg/mL. Most the female carp (86%) had concen­
Results and Discussion 85 

Table 31. Arithmetic mean of gonadosomatic index (GSI; %) by station, number of samples (n) , minimum (min.) maximum (max.), and 

standard error (SE) in the target species collected in the Columbia River Basin in 1997. Stations are grouped by taxon and sub-basin 

and ordered upstream to downstream. The maximum station mean for each taxon is shown in bold. 

Female	 Male Taxon and Station n Mean Min. Max. SE n Mean Min. Max. SE 

Bass 

Basin total 74

Upper Columbia River (UCR)

Creston, MT (117) 11

Snake River (SR)

Hagerman, ID (41) 9

Riggins, ID (43) 3

Lewiston, ID (42) 5

Ice Harbor Dam, WA (96) 4

Middle Columbia River (MCR)

Vernita Bridge, WA (503) 3

Pasco, WA (97) 9

Granger, WA (44) 9

Lower Columbia River (LCR)

Warrendale, OR (502) 1

Vancouver, WA (506) 0

Oregon City, OR (45) 15

Portland, OR (505) 5

1.7 0.0 7.2 0.2 60 0.46 0.0 1.7 0.0 

1.3 0.7 2.3 0.1 10 0.25 0.2 0.4 0.0 

1.5 0.2 2.0 0.2 7 0.38 0.2 0.5 0.0 

1.4 1.2 1.6 0.1 4 0.52 0.3 0.9 0.1 

0.5 0.0 0.9 0.2 7 0.49 0.0 0.7 0.1 

1.9 0.7 3.1 0.6 3 0.91 0.4 1.7 0.4 

2.1 1.7 2.6 0.3 2 0.85 0.8 0.9 0.0 

1.2 0.4 3.3 0.3 6 0.38 0.0 1.6 0.2 

1.5 0.5 2.4 0.2 6 0.55 0.2 0.9 0.1 

2.4 -- -- 3 0.83 0.6 1.0 0.1 

-- -- -- -- 1 0.95 -- --

2.9 0.5 7.2 0.6 6 0.32 0.2 0.5 0.0 

1.4 1.1 1.9 0.1 3 0.26 0.3 0.3 0.0 

Carp 

Basin total 70 

Snake River (SR)

Hagerman, ID (41) 10

Lewiston, ID (42) 5

Ice Harbor Dam, ID (96) 10

Middle Columbia River (MCR)

Vernita Bridge, WA (503) 10

Pasco, WA (97) 11

Granger, WA (44) 10

Lower Columbia River (LCR)

Warrendale, OR (502) 10

Oregon City, OR (45) 4

Beaver Army Terminal, OR (501) 0

10.3 0.6 20.5 0.6 87 5.8 0.0 11.0 0.2 

2.1 0.6 4.9 0.5 10 4.1 2.8 6.2 0.4 

10.8 5.9 13.2 1.3 12 4.4 0.0 6.0 0.5 

10.0 4.5 15.2 1.2 11 6.2 4.8 8.2 0.3 

10.8 3.5 19.5 1.5 11 4.8 1.1 8.8 0.8 

10.1 5.6 13.3 0.7 9 5.2 3.3 7.9 0.5 

12.9 8.0 17.7 1.0 10 6.9 3.7 11.0 0.6 

14.4 8.2 20.5 1.2 10 7.9 5.4 10.1 0.5 

14.3 12.1 16.9 1.2 10 6.4 4.8 7.8 0.3 

-- -- -- -- 4 7.2 6.1 8.4 0.6 

Largescale sucker 

Basin total 88 

Upper Columbia River (UCR)

Creston, MT (117) 4

Northport, WA (504) 10

Grand Coulee, WA (98) 10

Snake River (SR)

Riggins, ID (43) 11

Lower Columbia River (LCR)

Cascade Locks, OR (46) 11

Warrendale, OR (502) 3

Vancouver, WA (506) 11

Oregon City, OR (45) 6

Portland, OR (505) 11

Beaver Army Terminal, OR (501) 11

4.4 0.3 13.4 0.3 70 4.6 0.0 8.3 0.2 

4.8 3.6 7.0 0.8 6 3.4 0.0 5.6 1.0 

4.3 1.9 5.9 0.3 9 5.2 3.6 6.9 0.4 

2.6 1.1 4.2 0.2 10 4.4 3.5 5.7 0.3 

2.0 0.3 2.8 0.2 9 4.1 2.9 6.0 0.3 

4.1 2.6 6.2 0.3 9 5.4 4.2 8.0 0.4 

3.6 2.4 4.2 0.6 0 -- -- -- --

6.4 0.5 13.4 1.2 10 4.8 3.9 6.2 0.3 

3.4 1.9 4.5 0.4 0 -- -- -- --

4.3 3.2 5.5 0.3 10 4.6 3.2 5.7 0.3 

7.6 0.9 13.1 1.1 5 5.7 4.1 8.3 0.7 

trations of vtg between 0.1-3.0 mg/mL (Fig. 25). Only four 

female carp had concentrations of vtg >3.0 mg/mL, and three 

of these fish were from Station 42. Vitellogenin did not vary 

significantly among stations although developmental stage 

influenced concentrations of vtg in carp (Table 20). The greatest concentrations of fish vtg were found in stage-2 female 

carp; stage-0, -1, and -3 fish had lower concentrations of vtg 

although samples were limited to a few individual fish in 

these stages. A stage-0 female carp (Station 41) and a stage-3 

female (Station 502) had concentrations of vtg of 0.01 mg/mL 

and 0.12 mg/mL, respectively. In another study, female carp 

from the MRB had mean station concentrations of vtg as great 

as 2.9 mg/mL (McDonald and others, 2002). Schmitt and 

others (2004) reported female carp to have station mean concentrations of vtg of approximately 1-25 mg/mL in the RGB. 

Collection date did not appear to influence concentrations of 
S

S

SSSSS

S

SSS

SS

S

SS

6 

1.6 

86 Environmental Contaminants and their Effects on Fish 

8 

100 

GSI-female 

GSI-male 

vtg-female 

vtg in 1997, since low concentrations of vtg were collected on 

the same date as high concentrations in female carp from the 

same station. 

Mean percent atresia in carp was similar among CRB 

stations. Mean percent atresia was greatest (17.6%) in female 

carp at Station 42, ranging from 3-27% (Table 33). All other 

station means ranged from 0.2% at Station 41 to 10.9% at 

Station 96. Stations 42, 96, 97, and 503 had fish with percent 

mg/mL

%

%

4 

2 

0 

atresia >20% although most carp had <20% of eggs that were 

atretic (Fig. 25). These data did not support a difference in 

percent atresia among stations for female carp (Table 20). 

However, a trend of decreasing percent atresia was apparent 

(Fig. 25). Percent atresia station means in carp from the MRB 

ranged from approximately 0-25%, and a reference station 

from the study had <5% mean atresia (Schmitt and others, 

2002). Female carp in the RGB had 1-13% atresia (Schmitt 

and others, 2004). Female carp at Stations 42, 44, 96, 97, and 

503 had mean atresia >5% (Table 33). 

1.2 

0.8 

0.4 

0.0 

10

1 Male Carp 

0.1 Two male carp, one from Station 502 and one from 

Station 503, had histologically identified abnormalities. The 0.01 

abnormal carp tissue from Station 503 was a tumor of multiple 

0.001 cell origin with a leiomyoma, a tumor of smooth muscle, and a 

0.0001 seminoma, tumor of germ cell origin. The abnormal carp tis- vtg-male 

0.1 All male carp were identified as stage 2 (40%) and stage 

3 (60%) (Fig. 21). Most male carp from Stations 41, 42, 96, 

0.01 97, and 503 were stage 2; whereas, fish at Stations 44 and 501 

were mostly identified as stage 3 (Fig. 24). All males at Stations 45 and 502 were identified as stage 3. 0.001 

GSI in male bass varied among CRB stations. GSI was 

sue from Station 502 was a proliferation of fibrous tissue and 

inflammation. 

% mg/mL

30 

Upper 

Snake R. 

Lower 

atresia-female 

Columbia R. 

Mid 

Columbia R. Columbia R. 

10.1% (Table 31). Other station means ranged from 4.1-7.2%. 

Stations 44 and 502 had fish with GSI >9% (Fig. 25). Most 

20 (91%) of the male carp had a GSI of 2.5-9.0%. GSI in male 

carp varied significantly among stations with an increasing 

trend moving upstream to downstream (Fig. 25; Table 20). 10 

GSI station means in male carp ranged from approximately 

2-12% in the MRB (McDonald and others, 2002) and 1-13% 

greatest (7.9%) in male carp at Station 502, ranging from 5.4-

in the RGB (Schmitt and others, 2004). 

Most (87%) male carp had concentrations of vtg <LOD 

117504

(0.005 mg/mL). All of the detected concentrations of vtg were

98

41

434296

503

97

44

46

502506

45

505

501 

Station 

Figure 23. Reproductive health indicators by station in female and 

male bass (Micropterus sp.) collected in the Columbia River Basin 

in 1997. Indicators include gonadosomatic index (GSI), vitellogenin (vtg), and atresia. Shown for each group are points representing individual fish and the mean (red horizontal line), median 

(black horizontal line), interquartile range (box), and the 10th and 

90th percentiles (whiskers). Stations are ordered from upstream 

to downstream and are grouped by sub-basin. See Table 3 for 

station descriptions. 

measured in stage-3 males except in two fish; a stage-2 male at 

Station 503 (0.02 mg/mL) and a male that could not be staged 

(no normal gonadal tissue collected) at Station 502 (0.01 mg/ 

mL). Concentrations of vtg in male carp from Stations 45, 96, 

502, and 503 were 0.01-0.04 mg/mL (Table 32; Fig. 25). Concentrations of vtg in individual fish from Stations 45, 502, and 

503 were >0.01 mg/mL (Table 32), which indicates an estrogenic response in these fish. Most mean station concentrations 

of vtg in male carp were also near LOD (0.001 mg/mL) in the 

MRB (McDonald and others, 2002) and RGB (Schmitt and 

0 
Results and Discussion 87 

Table 32. Arithmetic mean of vitellogenin (vtg; mg/mL) by station, number of samples ( n ), minimum (min.), maximum (max.), and standard

 error (SE) in fish collected in the Columbia River Basin in 1997. Censored values were represented by one half the LOD in the 

computation of means. The percent of males that had detectable concentrations of vtg are also presented. Stations are grouped 

by taxon and sub-basin and ordered upstream to downstream. Samples for which gonads were unavailable were not included 

in this table. The maximum station mean for each taxon is shown in bold. 

Female Male Taxon and Station n Mean Min. Max. SE n % Mean Min. Max. SE 

Bass 

Basin total 69 2.70

Upper Columbia River (UCR)

Creston, MT (117) 11 0.93

Snake River (SR)

Hagerman, ID (41) 9 0.25

Riggins, ID (43) 2 6.95

Lewiston, ID (42) 3 0.06

Ice Harbor Dam, WA (96) 3 5.16

Middle Columbia River (MCR)

Vernita Bridge, WA (503) 3 14.29

Pasco, WA (97) 9 3.88

Granger, WA (44) 9 3.32

Lower Columbia River (LCR)

Warrendale, OR (502) 1 0.08

Oregon City, OR (45) 14 2.60

Portland, OR (505) 5 0.07

0.00 33.67 0.71 58 9 0.016 0.001 0.669 0.012 

0.16 2.36 0.20 10 10 0.008 0.001 0.083 0.008 

0.03 1.54 0.17 7 0 0.001 0.001 0.001 --

0.11 13.79 6.84 4 25 0.008 0.001 0.032 0.008 

0.03 0.09 0.02 7 14 0.002 0.001 0.011 0.002 

0.04 15.15 5.00 3 33 0.022 0.001 0.055 0.017 

12.13 17.67 1.71 2 0 0.001 0.001 0.001 --

0.00 33.67 3.72 6 17 0.112 0.001 0.669 0.112 

0.02 13.63 1.67 6 0 0.001 0.001 0.001 --

-- -- -- 2 0 0.001 0.001 0.001 --

0.001 17.41 1.25 6 0 0.001 0.001 0.001 --

0.001 0.14 0.03 3 0 0.001 0.001 0.001 --

Carp 

Basin total 70 1.57 

Snake River (SR)

Hagerman, ID (41) 10 0.70

Lewiston, ID (42) 5 3.94

Ice Harbor Dam, ID (96) 10 2.14

Middle Columbia River (MCR)

Vernita Bridge, WA (503) 10 1.38

Pasco, WA (97) 11 2.20

Granger, WA (44) 10 1.84

Lower Columbia River (LCR)

Warrendale, OR (502) 10 0.36

Oregon City, OR (45) 4 0.48

0.003 7.37 0.15 83 12 0.002 0.003 0.037 0.001 

0.01 2.81 0.30 10 0 0.003 0.003 0.003 --

1.44 7.37 1.04 12 0 0.003 0.003 0.003 --

1.46 3.11 0.21 11 9 0.001 0.003 0.009 0.001 

0.13 2.33 0.24 11 27 0.006 0.003 0.037 0.004 

1.36 2.99 0.16 9 0 0.003 0.003 0.003 --

0.54 2.89 0.23 10 0 0.003 0.003 0.003 --

0.003 1.00 0.10 10 60 0.008 0.003 0.035 0.003 

0.07 0.99 0.23 10 10 0.001 0.003 0.010 0.001 

Largescale sucker 

Basin total 66 38.78 

Upper Columbia River (UCR)

Creston, MT (117) 4 43.05

Northport, WA (504) 10 55.72

Grand Coulee, WA (98) 10 14.06

Snake River (SR)

Riggins, ID (43) 11 31.52

Lower Columbia River (LCR)

Cascade Locks, OR (46) 11 62.82

Warrendale, OR (502) 3 20.25

Oregon City, OR (45) 6 66.46

Portland, OR (505) 11 17.46

0.09 166.4 4.09 55 9 0.0163 0.0003 0.469 0.010 

0.09 80.80 16.62 6 16 0.052 0.0003 0.306 0.051 

27.19 119.1 8.00 9 0 0.0003 0.0003 0.0003 0.000 

0.10 46.71 5.32 10 20 0.049 0.0003 0.469 0.047 

3.55 63.82 6.36 9 0 0.0003 0.0003 0.0003 0.000 

0.38 128.8 10.27 9 11 0.003 0.0003 0.021 0.002 

4.41 34.66 8.76 0 -- -- -- -- --

1.26 166.4 22.98 0 -- -- -- -- --

0.61 31.94 3.14 10 10 0.007 0.0003 0.066 0.007 

Longnose sucker 

Upper Columbia River (UCR) 

Creston, MT (117) 10 16.9 0.00 63.57 7.51 1 100 0.006 -- -- --

Grand Coulee, WA (98) 1 4.06 -- -- -- 1 10 0.0003 -- -- --

others, 2004). Villeneuve and others (2002) determined male 

carp to have concentrations of vtg <0.002 mg/mL in a laboratory study. As in female carp, vtg in male carp did not vary 

significantly among CRB stations. 

Female Largescale Sucker 

Female largescale sucker were identified as stage 1 

(24%), stage 2 (50%), and stage 3 (25%) with one female in 

stage 5 at Station 98 (Fig. 21). Stage-2 females were present 

at all stations where largescale sucker were collected (Fig. 26). 

Stage-1 and stage-3 fish were each represented at five stations. 
88 Environmental Contaminants and their Effects on Fish 

Table 33. Arithmetic mean of percent atresia by station, number of samples ( n ), minimum (min.) 

maximum (max.), and standard error (SE) in female fish collected in the Columbia River Basin in 1997. 

Stations are grouped by taxon and sub-basin and ordered upstream to downstream. The maximum 

station mean is shown in bold for each taxon. 

Taxon and Station	 n Mean Min. Max. SE 

Bass 

Basin total 74

Upper Columbia River (UCR)

Creston, MT (117) 11

Snake River (SR)

Hagerman, ID (41) 9

Riggins, ID (43) 3

Lewiston, ID (42) 5

Ice Harbor Dam, WA (96) 4

Middle Columbia River (MCR)

Vernita Bridge, WA (503) 3

Pasco, WA (97) 9

Granger, WA (44) 9

Lower Columbia River (LCR)

Warrendale, OR (502) 1

Oregon City, OR (45) 15

Portland, OR (505) 5

3.4 0 32 0.5 

2.5 0 5 0.5 

7.1 0 32 3.3 

2.0 0 4 1.2 

3.2 0 11 2.2 

2.5 1 7 1.5 

4.0 3 6 1.0 

2.2 0 10 1.1 

1.3 0 5 0.6 

12.0 -- -- --

2.6 0 10 0.7 

6.2 2 14 2.2 

Carp 

Basin total 70 

Snake River (SR)

Hagerman, ID (41) 10

Lewiston, ID (42) 5

Ice Harbor Dam, ID (96) 10

Middle Columbia River (MCR)

Vernita Bridge, WA (503) 10

Pasco, WA (97) 11

Granger, WA (44) 10

Lower Columbia River (LCR)

Warrendale, OR (502) 10

Oregon City, OR (45) 4

6.6 0 30 0.9 

0.2 0 1 0.1 

17.6 3 27 4.5 

10.9 1 30 3.1 

8.7 0 27 2.6 

6.6 0 23 2.2 

5.9 0 16 1.8 

3.7 0 15 1.5 

2.0 1 4 0.7 

Largescale sucker 

Basin total 

Upper Columbia River (UCR)

Creston, MT (117)

Northport, WA (504)

Grand Coulee, WA (98)

Snake River (SR)

Riggins, ID (43)

Lower Columbia River (LCR)

Cascade Locks, OR (46)

Warrendale, OR (502)

Vancouver, WA (506)

Oregon City, OR (45)

Portland, OR (505)

Beaver Army Terminal, OR (501)

88 2.0 0 16 0.3 

4 1.8 0 4 1.0 

10 1.1 0 7 0.8 

10 2.5 1 6 0.5 

11 1.8 0 9 0.9 

11 3.7 0 16 1.4 

3 0.0 0 0 0 

11 0.9 0 6 0.6 

6 1.2 0 4 0.7 

11 4.1 0 12 1.2 

11 1.3 0 12 1.1 
Results and Discussion 89 

% 

100 

80 

60 

M F M F M F M F M F M F M F M F M 

41 

7 1 

7 

3 

2 

/97 

42 

/

57 

5 

96 

/

6 

5 

6 1 

9 

4 

97 

5 

4 

44 

/97 

2 2 

88 

9 9 

1 

45 

/

10 4 

501 

/

1 

3 

Stage 3 

Stage 2 

Stage 1 

Stage 0 

Snake R. Mid-Columbia R. Lower Columbia R. 

10/31-11/1 9/30 97 10/10-11 97 

10 

503 

10/13-14/97 10/8-9/97 

11 

10/15-16

502 

10/25-26/97 11/21-24 97 3/31-4 1/98 

40 

20 

0 

Station 

Figure 24. Gonadal stage proportions by station in female and male carp collected in the Columbia River Basin in 1997. Station sample 

sizes for each stage are located in the boxes within the figure. The collection dates for each station are located below the station number. Stations are ordered from upstream to downstream and are grouped by sub-basin. See Table 3 for station descriptions. 

GSI in female largescale sucker varied in the CRB. GSI 

was greatest (7.6%) in female largescale sucker from Station 501 ranging from 0.9-13.1% (Table 31), and other station 

means ranged from 2.0-6.4%. GSI >7% were measured in 

female largescale sucker from Stations 501 and 506 (Fig. 27) 

although most (90%) values ranging from 1.0-9.0%. GSI 

varied significantly among stations in female sucker (Table 

20), and GSI and stage had a significant correlation. Stage-3 

females had the greatest GSI values. 

The gender of largescale sucker influenced the reproductive biomarkers (Table 20), resulting in females and males 

being examined separately. Samples from Stations 501 and 

506 were not available for analysis. Mean vtg in female 

largescale sucker was greatest (66.4 mg/mL) at Station 45, 

ranging from 1.3-166.4 mg/mL (Table 32). Other station 

means for female largescale sucker ranged from 14.1-62.8 

mg/mL; concentrations of vtg did not vary significantly among 

stations. All stations had individual fish with high concentrations of vtg. Stations 45, 46, 117 and 504 had numerous 

largescale sucker with concentrations of vtg >50 mg/mL (Fig. 

27). As in female carp and bass, collection date did not appear 

to influence concentrations of vtg in largescale sucker, since 

low concentrations of vtg were collected on the same date as 

high concentrations from the same station. Previous vtg data 

are not available for largescale sucker. Concentrations of vtg 

in female longnose sucker from another BEST project with 

concentrations were <0.001-10.7 mg/mL (Hinck and others, in 

review). 

Atresia in female largescale sucker was examined in the 

CRB. Mean percent atresia was greatest (4.1%) in largescale 

sucker at Station 505, ranging from 0-12% (Table 33). All 

other station means were <3.7%. Atresia in fish from Stations 

46, 501 and 505 were >10%, although the majority (97%) 

of the females had <10% of eggs that were atretic (Fig. 27). 

Station means did not significantly differ for percent atresia, 

but Stations 46 and 505 generally had higher values (Fig. 27). 

Percent atresia data for largescale sucker have not been previously reported. 

Male Largescale Sucker 

Ninety-four percent of male largescale sucker were identified as stage 3 (Fig. 21). Two males at Station 43 were stage 

2, and two males at Station 117 were stage 0 (Fig. 26). 

GSI was greatest (5.7%) in male largescale sucker at 
S

S

SSSSS

S

SSS

SS

S

SS

25 

100 

0.01 

0.1 

90 Environmental Contaminants and their Effects on Fish 

Station 501 (Table 31) ranging from 4.1-8.3%; other station 

means ranged from 3.4-5.4%. Fish at Stations 46 and 501 had GSI-female 

GSI-male 

atresia-female 

vtg-female 

vtg-male 

Upper 

Columbia R. Snake R. 

MidColumbia R. 

Lower 

Columbia R. 

oocytic atresia) and vtg are the best techniques available for 

measuring reproductive function as well as the effects of 

contaminants, whether endocrine disrupting or on reproductive health. The biomarkers are influenced by age, species, 

20 

15 

10 

5 

0 

12 

GSI that exceeded 7% with most (93%) values ranged from 

2.5-7.0% (Fig. 27). GSI varied significantly among stations in 

male largescale sucker (Table 20). All male sucker were stage 

3 with the exception of four individual fish; therefore, evaluation of stage as a significant variable in predicting GSI was not 

possible. Previous GSI data are not available for largescale 

sucker. 

% mg/mL mg/mL

%

%

Concentrations of vtg in male largescale sucker were 

10 

8 

6 

4 

2 

0 

<LOD in 46 of 53 (87%) samples. Concentrations >LOD 

(0.0005 mg/mL) were found in fish at Stations 46, 98, 117, 

and 505, and detected concentrations of vtg were 0.001-0.47 

mg/mL (Table 32; Fig. 27). Male sucker from Stations 46, 

98, 117, and 505 had concentrations of vtg >0.01 mg/mL, a 

concentration that indicates an estrogenic response in these 

fish. These elevated concentrations were limited to individual 

fish at Stations 46, 177, and 505, but Station 98 had two fish 

with concentrations >0.01 mg/mL which may warrant fur10 

1 

0.1 

0.01 

0.001 

ther investigation of endocrine disrupting chemicals at this 

site. Previous vtg data are not available for largescale sucker. 

Concentrations of vtg from longnose sucker are available 

from another BEST project with concentrations ranging from 

<0.001-0.047 mg/mL (Hinck and others, in review). 

Reproductive Biomarker: Summary 

The biomarkers used in this study including GSI, gonadal 

histopathology (used for the analysis of gender, stage, and 

water temperature, photoperiod, and other biotic and abiotic 

30 

20 

10 

0 

factors and can greatly fluctuate during the reproductive cycle. 

A well-designed study controlling these variables can provide 

valuable data and important insights into reproductive health. 

These biomarkers have proven to be valuable measures of 

reproductive activity and dysfunction in a variety of laboratory 

studies, as well as several field studies (including this study) 

designed to monitor the effects of environmental contaminants 

on the reproductive activity in streams. 

The GSI is often used to evaluate reproductive status and 

117504

health, although interpretations of GSI measurements rely on

9841434296

503

974446

502506

45

505501 

understanding natural variations among fish of the same age, 

gender, and species. Environmental influence and behavioral 

patterns may also confound the data. Considerable gonad 

size variation has been reported throughout the reproductive 

cycle of many animal species (de Vlaming and others, 1981). 

Gonads constituted a substantially greater proportion of the 

total body mass in carp than in bass as noted in previous studies (for example, McDonald and others, 2002). GSI in largescale sucker were generally between those of carp and bass. 

Fish from Stations 41 (carp), 42 (male carp), and 43 (largeStation 

Figure 25. Reproductive health indicators by station in female and 

male carp collected in the Columbia River Basin in 1997. Indicators include gonadosomatic index (GSI), vitellogenin (vtg), and 

atresia. Shown for each group are points representing individual 

fish and the mean (red horizontal line), median (black horizontal 

line), interquartile range (box), and the 10th and 90th percentiles 

(whiskers). Stations are ordered from upstream to downstream 

and are grouped by sub-basin. See Table 3 for station descriptions. 
Results and Discussion 91 

% 

100 

80 

60 

Stage 5 

Stage 3 

Stage 2 

Stage 1 

Stage 0 

M F M F M F M F M F F M F F M F M F 

2 4 

4 

/

10 4 

6 

98 /

10 9 

1 

43 

2 

7 

1 

46 

9 7 

4 

502 

2 

1 

506 

10 1 

5 

5 

45 11/

2 

4 

505 

10 

1 

/

5 1 

1 

9 

117 

Upper Columbia R. Snake R. Lower Columbia R. 

9/24-25/97 

504 11/3-4 97 11/6-7 97 10/2/97 

10 

11/18-20/97 10/25-26/97 4/2/98 21-24/97 11/14-17/97 

10 

501 3/31-4/1 98 

40 

20 

0 

Station 

Figure 26. Gonadal stage proportions by station in female and male largescale sucker collected in the Columbia River Basin in 1997. 

Station sample sizes for each stage are located in the boxes within the figure. The collection dates for each station are located below 

the station number. Stations are ordered from upstream to downstream and are grouped by sub-basin. See Table 3 for station descriptions. 

scale sucker) consistently had relatively low GSI. The GSI in 

fish from Stations 502 (male carp and bass), 45 (female bass), 

501 (female largescale sucker), and 506 (female largescale 

sucker) were elevated. The GSI was low in individual fish 

from Stations 42 (bass) and 41 (carp). 

Gonadal histopathology was used in this study to confirm 

gender, assign reproductive stage, and detect anatomical 

abnormalities such as the presence of ovotestes and excessive 

oocyte atresia. In general, fish of the same gender/taxon were 

in similar stages of gonadal maturity, despite differences in 

sampling times and locations. Males were predominantly in 

stages 2 and 3, and females were in stages 1 and 2. Because 

the reproductive biomarkers used in this study are known 

to vary over the course of the reproductive cycle, stage was 

given close attention in the interpretation of these data. Those 

stations at which most fish were outside of the normal range 

of maturation were identified in the results section, and future 

efforts should be made to reveal the reason or reasons for 

either advanced or delayed gonadal development. 

Oocyte atresia, as defined by an involution or resorption 

of vitellogenic oocytes by the ovaries, has been sufficiently 

validated as a histological biomarker (that is, lesions in laboratory studies have been correlated with chemical exposure) and 

these same lesions detected in fish from contaminated sites. 

Although oocyte atresia is a normal physiological event in all 

fish, it can become a pathological condition following exposure to certain environmental contaminants (Cross and Hose, 

1988; 1989; Johnson and others, 1988; Kirubagaran and Joy 

1988); however, it is also important to note that other factors 

may also be involved (June, 1970; 1977). McDonald and others (2002) reported atresia ≥25% for female carp and >10% 

for female bass may be of concern and were defined as high. 

The percent atresia was < 20% for female carp, and <10% for 

female bass and largescale sucker in the CRB. High atresia 

values in individual fish were found at Station 42 for carp and 

bass, Stations 41 and 502 for bass, and Stations 46, 501, and 

505 for sucker. Carp at Station 42 had a high station mean 

percent atresia (17.6%). 

There was variability in the percent atresia among CRB 

stations although stations were not significantly different from 

one another (Tables 20 and 33) However, without a more 

thorough understanding of normal percentages in healthy individuals it is difficult to reach a conclusion regarding the degree 

of oocyte atresia that affects reproduction. Other biomark­
S

S

SSSSS

S

SSS

SS

S

SS

10 

10 

100 

1000 

0 

12 

16 

1 

92 Environmental Contaminants and their Effects on Fish 

16 ers appeared to be normal in female carp from the stations at GSI-female which mean atresia was high, except MAMM. Basin-wide 

mean oocyte atresia was less in female bass (3.4%) than 

female carp (6.6%), and lowest in largescale sucker (2.0%) 

12 

(Table 33). 

Five male smallmouth bass from two stations (Stations 

8 

42 and 502) were identified as histologically abnormal and 

having ovotestes; that is, they were male fish with foci of ovarian tissue. The significance of this is unclear because most 

4 

0 

% mg/mL mg/mL

%

%

of these males had normal GSI and low or undetectable vtg GSI-male 

vtg-female 

vtg-male 

well as in female carp at Station 502. However, incidences of 

high concentrations of vtg were not consistent across species/ 

taxon. Concentrations of vtg in female largescale sucker were 

1 

0.1 consistently 15-20 times greater than concentrations in female 

concentrations. To our knowledge, the background occur­ 8 

6 

4 

2 

0 

rence of intersex male bass has not been established. These 

fish with ovotestes were not functional hermaphrodites. The 

testes appeared functional and contained later stages of spermatogenesis (that is, having mature sperm), and the oocytes 

were characterized by only a few previtellogenic, very small 

oocytes. Other studies have reported high proportions (>40%) 

of largemouth bass (Schmitt and others, 2004) and smallmouth 

bass (McDonald and others, 2002) with ovotestes at certain 

sampling locations in the U.S. 

Relatively low concentrations of vtg were recorded for 

female bass and largescale sucker at Stations 502 and 505 as 

bass and carp. Individual female bass had high concentrations at Stations 97 and 503, and a male bass at Station 97 

had a vtg concentration of 0.67 mg/mL, a level that indicates 

exposure to endocrine disrupting chemicals. Individual male 

bass from Stations 42, 43, 96, 97, and 117 had concentrations 

of vtg >0.01 mg/mL. These results did not indicate a general 

estrogenic response in male bass at any of these stations. With 

the exception of two relatively high concentrations in female 

carp at Station 42, no station was notable for vtg in female 

0.1 

0.01 

0.001 

0.0001 

atresia-female 

Upper 

Columbia R. Snake R. 

MidColumbia R. 

Lower 

Columbia R. 

indicates an estrogenic response at these two sites. Mean 

station concentrations of vtg were greatest (>60 mg/mL) for 

female largescale sucker at Stations 45 and 46. Male larges8 

4 cale sucker from Stations 46, 98, 117, and 505 had concentrations of vtg >0.01 mg/mL. Male sucker from Stations 98 

carp. Male carp from Stations 45, 502, and 503 had concentrations of vtg >0.01 mg/mL, and multiple male individuals 

from Stations 502 and 503 exceeded this concentration which 

and 117 had very high concentrations of vtg (>0.30 mg/mL), 

which indicates these fish had estrogenic responses as a result 

of exposure to environmental conditions at these sites. Recent

117504

9841434296

503

974446

502506

45

505501 

Station 

Figure 27. Reproductive health indicators by station in female and 

male largescale sucker collected in the Columbia River Basin in 

1997. Indicators include gonadosomatic index (GSI), vitellogenin 

(vtg), and atresia. Shown for each group are points representing 

individual fish and the mean (red horizontal line), median (black 

horizontal line), interquartile range (box), and the 10th and 90th 

percentiles (whiskers). Stations are ordered from upstream to 

downstream and are grouped by sub-basin. See Table 3 for station descriptions. 

studies have localized vtg receptors to the testes, muscle, and 

spermatocytes (Bidwell and Carlson, 1995; Tao and others, 

1996). 

A 1995 reconnaissance study by Goodbred and others 

(1997) reported detectable concentrations of vtg in males from 

the reference site and confirmed that small amounts of vtg can 

be present in healthy males. Vitellogenin was measured in 

male bass from Stations 43, 96, 97, and 117, male carp from 

Stations 45, 96, 502, and 503, and male largescale sucker from 

Stations 46, 98, 117, and 505. The females from these same 
93 

stations did not have elevated concentrations of vtg; therefore, 

elevated concentrations of vtg were gender specific at CRB 

stations. Station 502 was the only site with more than three 

male fish with detectable concentrations of vtg. Concentrations of vtg ranged from 0.007-0.035 mg/mL in male carp 

from Station 502. Stations 96 and 117 had measured vtg in 

bass and carp. Stations with vitellogenic males were distributed throughout the CRB, and the SR only had one station 

where vtg was detected in male fish. 

Concentrations of vtg were correlated with stage and 

differed significantly among stages for female bass from the 

CRB. Indeed, stage assessments are based in part on the deposition of vitelline granules in the developing oocyte; therefore, 

it is not surprising that stage and vtg in females are correlated. 

Although fish were collected in their non-reproductive season, 

sampling took three months to complete. Therefore, it is 

reasonable that female fish collected months apart could be in 

different stages of their respective reproductive cycle. Low or 

non-detectable concentrations of vtg in fish at Stations 42 and 

505 did not seem to be related to sampling time (late September for Station 42 and mid-November for Station 505). At 

both stations, the females analyzed were almost exclusively in 

stage 0 and 1. At many of the stations with higher vtg means, 

such as Stations 43 and 503, fish were also predominantly in 

stage 1. Both of these stations were also sampled late in the 

fall. Thus, while sampling over a six-month period is not ideal 

for assessing any of the reproductive biomarkers, it did not 

appear to be the reason for differences in stage. However, geographical location is another potentially complicating factor. 

Only one female carp in this study had a concentration of vtg <LOD, although several station means were low. 

Female carp were predominantly stage 2 (83%). Even so, vtg 

concentrations of stage-2 females ranged from <0.005-7.4 

mg/mL. Although the stations (Stations 45 and 502) with the 

lowest vtg means were also among the latest sites sampled 

(late November), most female carp (and the only individuals contributing to the station means) were stage 2. Thus, 

late collection, immature gonads, or both are not reasonable 

explanations for the variability observed. In addition, the age 

of the fish collected for the study did not appear to influence 

the reproductive stage of the gonads. 

All female largescale sucker in this study had concentrations of vtg >LOD. Female largescale sucker were predominantly stage 2 (56%) with concentrations ranging from 

0.087-166 mg/mL. Stage-1 females were predominantly from 

Stations 43 and 46 and had vtg concentrations ranging from 

0.375-87 mg/mL. Stage-3 females were mainly from Station 

504 with concentrations ranging from 27-119 mg/mL. One 

female from Station 98 was identified as stage 5 with a vtg 

concentration of 0.225 mg/mL. Neither stage nor age were 

correlated with vtg and all largescale sucker were collected 

near the same period of time (late fall). 

Results and Discussion 

Spatial patterns in contaminant concentrations 

and biomarker responses 

Geographic Summaries 

Geographic station summaries were made to highlight 

elevated contaminant concentrations and biomarker responses 

(Table 34). The highlighted findings indicate contaminant 

concentrations or EROD levels that exceeded known thresholds or were anomalous (that is, high or low) relative to other 

stations in the CRB. The colors for the reproductive and fish 

health biomarkers are relative and indicate the number and/or 

magnitude of the anomalies (including the number of gendertaxon categories in which they occurred) at a station. The 

summaries are intended only to draw attention to particular 

stations highlighted in the text, possibly for further investigation. It is important to recognize that increased frequencies of external lesions or elevated health assessment index 

(HAI) scores, which represent the cumulative total number of 

grossly visible internal and external lesions, do not necessarily 

indicate direct contaminant effects. Unfortunately, most of the 

lesions were not collected for histological examination. The 

two lesions that were collected exhibited epidermal erosion 

and inflammation. Many factors other than contaminants 

can indirectly influence fish health indicators and reproductive biomarkers including nutrients or organic matter and 

water temperature (see fish health indicator and reproductive 

biomarkers sections). More studies have determined criteria 

that assesses risk to fish and piscivorous wildlife associated 

with bioaccumulative contaminants and EROD than about 

long- and short-term risks represented by the other biomarkers. Therefore, greater relative risk has been associated with 

elevated contaminant concentrations and EROD rates than 

with anomalous fish health or reproductive biomarkers (Table 

34). 

Upper Columbia River (UCR) 

The UCR includes Stations 117, 504, and 98. Male and 

female largescale sucker were collected from all stations; 

however, different predator species were collected from each 

station. Walleye were collected from Station 98, rainbow 

trout were collected from Station 504, and bass were collected 

from Station 117. Longnose sucker were also collected from 

Stations 98 and 117. The UCR stations were sampled in early 

November 1997. Mercury impairments have been previously 

reported in the UCR from Roosevelt Lake to the international border (USEPA, 2002b). Fish consumption advisories 

have been issued for Lake Roosevelt for dioxins in whitefish 

(USEPA, 2003a), which have been attributed to a pulp mill in 

British Columbia, Canada (Schneider, 2002). 
94 Environmental Contaminants and their Effects on Fish 

Table 34. Summary of chemical and biological indicator results, by sub-basin and station. Within each column, colors indicate the severity, 

incidence, or both of the indicated condition or conditions at each station (green<yellow<red). These designations are relative; see text 

for explanations. Male and female bass, carp, and largescale sucker were collected from all sites unless otherwise indicated. See Table 3 and 

Figure 1 for station and sub-basin locations. Bold lettering denotes that threshold criteria was exceeded and/or high incidence of elevated 

occurrence. DDE, p ,p' -DDE; chlordane, total chlordanes; PCB, polychlorinated biphenyls; TCDD-EQ, dioxin-like activity as determined by 

H4IIE bioassay; Hg, mercury; Pb, lead; Se, selenium; EROD, ethoxyresorufin O -deethylase; SSI, splenosomatic index; HAI, health assessment 

index; HSI, hepatosomatic index; MA, macrophage aggregates (one or more parameters); vtg, vitellogenin; ovt, ovotestis; b, bass (Micropterus sp.); 

c, carp (Cyprinus carpio ); s, largescale sucker (Catostomus macrocheilus ); m, male; f, female. For SSI, - indicates smaller; all others larger. 

Sub-basin and Station Contaminants and EROD Fish Health Indicators Reproductive Biomarkers 

Upper Columbia River (UCR) 

117 (no carp) Hg (b), EROD (b,s) SSI (s), Ext. lesions (b,s) Vtg (ms) 

504 (sucker only) Hg, Pb, PCB, TCDD-EQ, EROD SSI, Ext. lesions 

98 (sucker only) Hg, Pb, EROD SSI, Ext. lesions Vtg (ms) 

Snake River (SR) 

41 (no sucker) Hg (b), EROD (c) Ext. lesions (c,b), HAI (b) 

43 (no carp) Hg (b), Se (b), EROD (b,s) 

42 (no sucker) Hg (b,c), DDE (c), chlordane (c), PCB (b,c), 

EROD (b,c) 

SSI (fc-), Ext. lesions (c), MA (c) Ovt (mb) 

96 (no sucker) Hg (b), DDE (c), PCB (c), TCDD-EQ (c,b), 

EROD (b,c) 

Ext. lesions (c) 

Mid-Columbia River (MCR) 

503 (no sucker) Hg (b), Se (b), DDE (c,b), PCB (c,b), TCDD-EQ 

(c,b), EROD (c) 

Ext. lesion (c), HSI (fb) Vtg (mc) 

97 (no sucker) Hg (b), Se (c,b), TCDD-EQ (c,b), EROD (b) Vtg (mb) 

44 (no sucker) Hg (b), DDE (c,b), PCB (b), EROD (c,b) Ext. lesions (c,b), HAI (b) 

Lower Columbia River (LCR) 

46 (sucker only) Hg, PCB, TCDD-EQ, EROD Ext. lesions 

502 (no m sucker) Hg (b,c), PCB (b,c), TCDD-EQ (c), EROD 

(c,s,b) 

Ext. lesions (c,b) Vtg (mc), Ovt (mb) 

506 (no carp, f bass) Hg (s), Toxaphene (s), PCB (s), TCDD-EQ (s) Ext. lesions (s) 

45 (no m sucker) Hg (b,c,s), PCB (c), TCDD-EQ (c,b), EROD 

(c,s,b) 

Ext. lesions (c,b,s), HAI (b) 

505 (no carp) Hg (b,s), PCB (b,s), TCDD-EQ (b,s), EROD 

(b,s) 

Ext. lesions (b,s) 

501 (no bass, f carp) DDE (c,s), PCB (c,s) Ext. lesions (c,s) 

Station 117 (Creston, Montana) 

Several contaminants and biomarkers were highlighted 

in fish at Station 117 (Table 34). The concentration of Hg in 

female bass (0.31 μg/g ww) exceeded criteria (0.3 μg/g ww) 

shown to cause reproductive impairment in loons (Barr, 1986) 

(Fig. 28). No other inorganic and organic contaminant concentrations exceeded criteria at Station 117. The mean station 

EROD activity exceeded basal levels set in the BEST 1995 

MRB study for male and female bass and female largescale 

sucker indicating exposure to exogenous AhR agonists (Fig. 

29). Largescale sucker from Station 117 had the greatest 

mean SSI (0.37%) of all CRB stations. External lesions were 

identified on >50% of the bass and largescale sucker collected 

from this station. However, most of these lesions were classified as fin abnormalities which could result from factors other 

than environmental contamination. Vitellogenin was the only 

reproductive biomarker highlighted at this station. Concentrations of vtg were >0.01 mg/mL in male bass (0.08 mg/mL) 

and male largescale sucker (0.31 mg/mL), which indicates 

an estrogenic response to environmental conditions in these 

individual fish (Table 34; Fig. 30). 

Station 504 (Northport, Washington) 

Fish at Station 504 exceeded threshold levels for numerous contaminants and several fish health biomarkers (Table 

34). The concentration of Hg in male largescale sucker (0.15 

μg/g ww) exceeded criteria (0.1 μg/g ww) shown to cause 

reproductive problems in mallards (Heinz, 1979) (Fig. 28). 

The concentrations of Pb in male and female largescale sucker 

were the greatest (>4.0 μg/g ww) in the CRB and exceeded 

numerous criteria (Fig. 28). Concentrations of PCBs in female 

largescale sucker and male rainbow trout exceeded the NYSDEC wildlife guideline of 0.11 μg/g ww (Newell and others, 

1987). The TCDD-EQ, a measure of dioxin-like activity, for 

female largescale sucker was 5 pg/g, the dietary threshold 
for avian wildlife (Nosek and others, 1992). Station mean 

EROD activity exceeded 10 pmol/min/mg for male largescale 

sucker indicating exposure to exogenous AhR agonists (Fig. 

29). Fish health indicators highlighted for this station include 

SSI and external lesions. Station 504 had the second highest 

mean SSI (0.36%) for largescale sucker throughout the CRB. 

Eighty-five percent of largescale sucker were identified as having external lesions, mostly located on the body surface and 

fins. Five of these external lesions were papillomas and two 

had thickened areas of epithelium with accumulations of pigmented macrophages around vessels in the dermis. One papilloma was an eye lesion composed of chronic granulomatosis 

inflammation throughout the choroids, iris and, retina. These 

lesions are similar to those previously described for Streptococcus and Staphylococcus infections of fish. No reproductive 

biomarker appeared to be anomalous at this station.

Station 98 (Grand Coulee, Washington)

Multiple contaminant concentrations, fish health indicators, and reproductive biomarkers were highlighted in fish at 

Station 98 (Table 34). The concentration of Hg in male and 

female largescale sucker and male walleye exceeded criteria 

(0.1 μg/g ww) shown to cause reproductive problems in mallards (Heinz, 1979) (Fig. 28). The concentrations of Pb in 

male and female largescale sucker exceeded criteria for reproduction success in multi-generational brook trout (Holcombe 

and others, 1976) (Fig. 28). Station mean EROD activity 

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41 Hg (μg/g) 

 <0.1 

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 >0.3 

Se (μg/g) 

 <0.6 

 0.6-0.8 

>0.8 

Pb (μg/g) 

 <0.4 

 >0.4 

Figure 28. Maximum concentrations (μg/g ww) of mercury (Hg, 

upper panel), selenium (Se, middle panel), and lead (Pb, lower 

panel) in composite samples of whole fish. A concentration of Hg 

of 0.1 μg/g ww in fish has been suggested as a guideline for the 

protection of piscivorous mammals (Yeardley and others, 1998), 

and concentrations of 0.3 μg/g ww cause reproductive impairment 

in the common loon (Gavia immer) (Wiener and Spry, 1996; Wiener 

and others, 2002). For Se, concentrations should be <0.6 μg/g ww 

to avoid toxicity to piscivorous wildlife and <0.8 μg/g ww to avoid 

toxicity to fish (Lemly, 1996). Concentrations of Pb of 0.04 μg/g ww 

have reduced egg hatch ability in brook trout (Holcombe and others, 1976). See Table 3 for station descriptions.

Results and Discussion 95
exceeded 10 pmol/min/mg for male and female largescale 

sucker indicating exposure to exogenous AhR agonists (Fig. 

29). External lesions were identified on 71% of the largescale 

sucker collected from this station. Most of these lesions were 

classified as eyes that were opaque which could result from 

factors other than environmental contaminants. Histologically, 

the eye lesions were composed of chronic granulomatosis 

inflammation in the choroid gland, cornea, and retina. Concentrations of vtg were >0.01 mm/mL in two male largescale 

sucker (0.02 mg/mL and 0.47 mg/mL), which indicates that 

exposure to endocrine disrupting chemicals is a concern at this 

site (Table 34; Fig. 30).

Snake River (SR)

Stations 41, 43, 42, and 96 were included in the SR. 

Both male and female bass and carp were collected from 

all stations except Station 43 where bass, largescale sucker, 

and northern pikeminnow were collected. The SR stations 

were sampled from late-September to early October in 1997. 

Mercury impairments have been previously reported in the 

SR from the Salmon River to the Washington border (USEPA, 

2002b). The SR is under a fish consumption advisory for all 

fish, beginning at the Oregon/Washington border and terminating below the town of Adrian (USEPA, 2003a). The Brownlee 

Reservoir, located on the mainstem of SR, was also issued a 

fish consumption advisory in 1994 because of Hg in carp and 

game fish (USEPA, 2003a). NAWQA reported pesticides 

were detected in surface water in spring and early summer following seasonal applications and high nutrient and sediment 

inputs from fish hatcheries, municipal wastewater, and irrigation returns in the SR (Clark and others, 1998).

Figure 29. Mean hepatic ethoxyresorufin O-deethylase (EROD) 

activity (pmol/min/mg protein) in bass (upper panel), carp (middle 

panel), and largescale sucker (lower panel). The thresholds 

indicated are levels identified in previous studies as indicative of 

exposure to exogenous Ah-R agonists (Schmitt and others, 2002b). 

See Table 3 for station descriptions.

S

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41 EROD (pmol/min/mg): Bass

 Male <22 or Female <16 

 Male ≥22 or Female ≥16 

 No Data 

EROD (pmol/min/mg): Common Carp

 Male <6 or Female <4 

 Male ≥6 or Female ≥4

 No Data 

EROD (pmol/min/mg): Largescale Sucker

 <10 

≥10 

 No Data 

96 Environmental Contaminants and their Effects on Fish
Station 41 (Hagerman, Idaho)

Several contaminants and biomarkers were highlighted 

at Station 41 (Table 34). The concentration of Hg in male 

and female bass exceeded criteria (0.1 μg/g ww) shown to 

cause reproductive problems in mallards (Heinz, 1979) (Fig. 

28). However, concentrations of Hg in carp were <LOD. No 

other inorganic or organic contaminant were not measured at 

concentrations of concern. TCDD-EQs were detected but did 

not exceed criteria in bass or carp. EROD activity exceeded 

levels set in the BEST 1995 MRB study for individual female 

carp, but the station mean (2.01 pmol/min/mg) did not exceed 

this criteria (Fig. 29). External lesions and HAI were the only 

fish health indicators highlighted at this station. External 

lesions were identified in 100% of carp and 88% of bass, the 

greatest percentages in the CRB. Most of the lesions were 

categorized as frayed and/or hemorrhagic fins. These are 

common abnormalities of fish that are not necessarily associated with contaminant influences. These external lesions and 

liver abnormalities were the main contributors of the inflated 

HAI scores of bass, which were the greatest in the CRB. The 

liver, kidney and spleen abnormalities identified during the 

field examination as white spots, nodules, and discolorations, 

were histologically identified as large numbers of helminth 

parasites with a few myxosporidian cysts in the kidney. Most 

of the skin lesions were proliferations of epidermal cells 

(mucous and epithelial) and inflammation, also in response to 

helminth parasites. Four of the fish had nodules of hyperplastic interrenal tissue within the anterior kidney. This could be 

indicative of chronic stress. No reproductive biomarkers were 

highlighted in fish at Station 41.

Station 43 (Riggins, Idaho)

Fish at Station 43 had several contaminants and biomarkers that exceeded criteria or were anomalous (Table 

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41

Vtg (mg/mL): Bass (males)

 <0.01 

≥0.01 

 No Data 

Vtg (mg/mL): Common carp (males)

 <0.01 

≥0.01 

 No Data 

Vtg (mg/mL): Largescale sucker (males)

 <0.01 

≥0.01 

 No Data 

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41

Figure 30. Plasma vitellogenin (vtg) in male bass (upper panel) 

carp (middle panel), and largescale sucker (lower panel). These 

thresholds indicate stations where at least one male bass had a 

detectable concentration of vtg (>0.01 mg/mL). See Table 3 for 

station descriptions.

Results and Discussion 97
98 Environmental Contaminants and their Effects on Fish 

34). Concentrations of Hg in the predators species, bass and 

northern pikeminnow, were the greatest (>0.4 μg/g ww) measured in the CRB and exceeded criteria (0.3 μg/g ww) shown 

to cause reproductive impairment in loons (Barr, 1986) (Fig. 

28). The concentration of Se in bass (0.84 μg/g ww) exceeded 

guidelines to protect fish and piscivorous wildlife (Lemly, 

1996). Organochlorine concentrations did not exceed criteria 

at this station. Dioxin-like activity as indicated by measurable 

amounts of TCDD-EQ was detected in female northern pikeminnow and bass but did not exceed criteria. The mean station 

EROD activity exceeded basal levels set in the BEST 1995 

MRB study for female bass (16 pmol/min/mg) and female 

largescale sucker (10 pmol/min/mg) with the station mean of 

male sucker (30.5 pmol/min/mg) being the greatest in the CRB 

(Fig. 29). No fish health indicators and only one reproductive 

biomarker, vtg, were highlighted at Station 43 (Fig. 30). Vtg 

was detected in one male bass (0.03 mg/mL); however, general 

exposure to endocrine disrupting chemicals at this site was not 

supported. 

Station 42 (Lewiston, Idaho) 

Multiple contaminants and biomarkers were highlighted 

in fish at Station 42 (Table 34). All samples had concentrations of Hg that exceeded criteria (0.1 μg/g ww) shown to 

cause reproductive problems in mallards (Heinz, 1979) (Fig. 

28). Concentrations of p,p’-DDE in male and female carp 

(>0.5 μg/g ww) exceeded several wildlife guidelines (Anderson and others, 1975; Jarvinen and Ankley, 1999; Newell and 

others, 1987). Male carp from Station 42 had the greatest 

concentration of total chlordane (0.13 μg/g ww) measured in 

the CRB, but the station mean was less than toxicity thresholds (Fig. 31). Concentrations of PCBs in male and female 

carp and male bass exceeded the NYSDEC wildlife guideline of 0.11 μg/g ww (Newell and others, 1987). Dieldrin 

was detected but trace concentrations were less than toxicity threshold to protect predatory fish and fish-eating birds. 

EROD activity exceeded levels set in the BEST 1995 MRB 

study for individual carp and bass, but only the station mean 

(16.3 pmol/min/mg) for female bass approached the criteria 

(16 pmol/min/mg) (Fig. 29). Several fish health indicators 

including SSI, external lesions, and macrophage aggregates 

were noteworthy at this station. Station 42 had the greatest 

SSI (0.25%) of bass in the CRB, while female carp from this 

station had lowest SSI (0.15%) of carp in the CRB. More than 

50% of the carp were identified as having external lesions, 

with most occurring on the body surface and fins. Mean station macrophage aggregate density (MAMM) in carp (10.2 

MA/mm2

) was the greatest of all CRB stations. Perhaps the 

most interesting discovery at Station 42 was that three of five 

male bass had ovotestes, although other reproductive biomarkers (that is, GSI and vtg) for these individuals appeared 

normal. 

Station 96 (Ice Harbor Dam, Washington) 

Fish at Station 96 had multiple contaminants and biomarkers that were of concern (Table 34). Carp and bass had 

concentrations of Hg near 0.1 μg/g ww, the criteria shown to 

cause reproductive problems in mallards (Heinz, 1979) (Fig. 

28). Concentrations of p,p’-DDE in male and female carp 

(>0.7 μg/g ww) exceeded several wildlife guidelines (Anderson and others, 1975; Jarvinen and Ankley, 1999; Newell and 

others, 1987). A similar pattern of p,p’-DDE in carp was 

identified at Station 42. Concentrations of PCBs in male and 

female carp (>0.2 μg/g ww) also exceeded criteria at Station 

96, but concentrations in bass were ≤LOD (Fig. 32). Dieldrin 

was detected, but trace concentrations were less than toxicity threshold to protect predatory fish and fish-eating birds. 

Female carp had the greatest TCDD-EQ (43 pg/g) measured in 

the CRB, and bass also had dioxin-like activity >5 pg/g (Fig. 

32). EROD activity exceeded levels set in the BEST 1995 

MRB study for individual male carp and female bass, but only 

the station mean (8.8 pmol/min/mg) for male carp exceeded 

the criteria (6 pmol/min/mg) (Fig. 29). More than 50% of the 

carp and bass were identified as having external lesions, with 

most occurring on the body surface and fins. However, body 

and fin abnormalities could result from factors other than environmental contamination. Vitellogenin was the only reproductive biomarker of concern at Station 96 with a single male bass 

having a concentration of 0.06 mg/mL (Fig. 30). 

Middle Columbia River (MCR) 

The MCR includes Stations 503, 97, and 44. Male and 

female bass and carp were collected from all stations; northern 

pikeminnow were also collected from Stations 44 and 503. 

The MCR stations were sampled in mid-October in 1997. 

Water quality impairments for p,p’-DDT, p,p’-DDE, and 

dieldrin have been reported for reaches throughout the Yakima 

River and reservoirs that are located in predominantly agricultural areas, and PCB and Hg impairments have also been 

reported (USEPA, 2002b). An advisory for p,p’-DDT and 

p,p’-DDE in all bottom fish was issued for the Yakima River, 

all its tributaries, and agricultural drains between the city of 

Yakima and its confluence with the Columbia River (USEPA, 

2003a). The NAWQA program also reported pesticides in 

surface water and PCBs in sediment were frequently detected 

in the MCR (Williamson and others, 1998). 

Station 503 (Vernita Bridge, Washington) 

Several contaminants and biomarkers were at concentrations or levels of concern in fish at Station 503 (Table 34). 

Concentrations of Hg in bass (0.15 μg/g ww), carp (0.10 μg/g 

ww), and northern pikeminnow (0.30 μg/g ww) exceeded 

one or more guidelines to protect wildlife (Barr, 1986; Heinz, 

1979) (Fig. 28). The concentration of Se in bass (0.70 μg/g 

ww) exceeded guidelines to protect fish and piscivorous 
wildlife (Lemly, 1996). Fish from Station 503 had among the 

greatest PCB concentrations measured in the CRB with a geometric station mean of 0.49 μg/g ww (Fig. 32). TCDD-EQs 

in all fish samples were also greater than the dietary threshold 

for avian wildlife (5 pg/g) (Nosek and others, 1992). Mean 

EROD activity in male carp (10.9 pmol/min/mg) exceeded criteria from the 1995 BEST MRB project (Schmitt and others, 

2002b), while mean EROD activity in the other fish from this 

site were not of concern (Fig. 29). Two fish health indicators, 

external lesions and HSI, were anomalous at in fish Station 

503. External lesions were identified in 86% of carp and 

80% of northern pikeminnow with most abnormalities being 

attributed to frayed or hemorrhagic fins, conditions that are 

not necessarily a result of contaminant exposure. The greatest 

mean HSI (2.33%) in the CRB was measured in female bass. 

Concentrations of vtg >0.01 mg/mL were measured in two 

male carp (0.02 mg/mL and 0.04 mg/mL), which is a concentration indicative of an estrogenic response to environmental 

conditions (Fig. 30). The mean concentration of vtg in female 

bass (14.3 mg/mL) was at least two times greater than bass 

from other CRB stations.

Station 97 (Pasco, Washington)

Fish at Station 97 had several contaminants and one 

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41 Toxaphene (μg/g) 

 <0.04 

≥0.04 

Total Chlordanes (μg/g) 

 <0.1 

 0.1-0.3 

Total p,p’-DDT (μg/g) 

 <0.15 

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$T

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41

Figure 31. Maximum concentrations (μg/g ww) of total DDT 

(upper panel, p,p’-homologs), toxaphene (middle panel), and total 

chlordanes (lower panel, sum of six components) in composite 

samples of whole fish. Concentrations of total DDT of 0.15 μg/g 

ww are potentially harmful to the brown pelican (Pelicanus occidentalis), the most sensitive avian species (Anderson, 1975), and 

1–3 μg/g ww is potentially harmful to other piscivorous birds (Blus, 

1996). For toxaphene, reviews by Jarvinen and Ankley (1999) and 

Eisler and Jacknow (1985) noted acute and chronic effects on 

freshwater fish at whole-body concentration ≥0.04 μg/g ww. For 

chlordane, concentrations >0.1 μg/g ww may affect the health 

of predatory fish and piscivorous birds (Eisler, 1990). See Table 

3 for station descriptions and text for explanation of chlordane 

components.

Results and Discussion 99
reproductive biomarker highlighted (Table 34). Female bass 

had a concentration of Hg (0.18 μg/g ww) that exceeded the 

criteria shown to cause reproductive problems in mallards 

(Heinz, 1979) (Fig. 28). Concentrations of Se from bass and 

carp (>0.8 μg/g ww) were the greatest measured in the CRB 

and exceeding guidelines to protect fish and piscivorous wildlife (Lemly, 1996). The TCDD-EQ for male and female bass 

and male carp exceeded 5 pg/g, the dietary threshold for avian 

wildlife (Nosek and others, 1992). EROD activity exceeding 

levels determined in the BEST 1995 MRB study for individual 

male and female bass, but the station means did not exceed 

the criteria (Fig. 29). Fish health indicators appeared normal 

at Station 97, and vtg was the only anomalous reproductive 

indicator. The concentration of vtg (0.67 mg/mL) in one male 

bass greatly exceeded detection limits and indicated that this 

male had an estrogenic response to environmental conditions 

at this site (Fig. 30). Both male and female bass had the greatest individual concentrations of vtg measured in the CRB.

Station 44 (Granger, Washington)

Multiple contaminants and several fish health indicators 

were highlighted in fish at Station 44 (Table 34). Concentrations of Hg in bass (>0.17 μg/g ww), carp (0.16 μg/g ww), and 

northern pikeminnow (0.48 μg/g ww) exceeded one or more 

guidelines to protect wildlife (Barr, 1986; Heinz, 1979) (Fig. 

28). Fish from Station 44 had some of the greatest concentrations of p,p’-DDE including male carp (1.0 μg/g ww), male 

and female bass (>0.9 μg/g ww), and female northern pikeminnow (0.8 μg/g ww). These concentrations of p,p’-DDE 

exceeded one or more wildlife guidelines (Anderson and 

others, 1975; Jarvinen and Ankley, 1999; Newell and oth-

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41

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41 Total PCBs (μg/g) 

 <0.11 

 0.11-1.0 

 >1.0 

TCDD-EQ (pg/g)

 <1.0 

 1.0-5.0 

 >5.0 

Figure 32. Maximum concentrations of PCBs (μg/g ww, upper 

panel) and TCDD-EQ (pg/g, lower panel) in composite samples of 

whole fish. The NYSDEC wildlife guideline for total PCBs is 0.11 

μg/g ww (Newell and others, 1987). TCDD-EQ levels >5 pg/g are 

potentially toxic to piscivorous avian and mammalian consumers 

wildlife, but the threshold for toxicity to fish is approximately 35 

pg/g (Nosek and others, 1992). See Table 3 for station descriptions.

100 Environmental Contaminants and their Effects on Fish
ers, 1987). Concentrations of PCBs in male carp (0.16 μg/g 

ww), male and female bass (0.12-0.62 μg/g ww), and female 

northern pikeminnow (0.17 μg/g ww) exceeded the NYSDEC 

wildlife guideline of 0.11 μg/g ww (Newell and others, 1987). 

Dioxin-like activity was detected in fish samples from Station 

44 but did not exceed criteria (5 pg/g) (Nosek and others, 

1992). EROD activity exceeded basal levels for individual 

bass and carp, but the station means did not exceed the criteria (Fig. 29). External lesions and HAI were the only fish 

health indicators of concern at Station 44. External lesions 

were identified on 100% of the fish from Station 44 although 

most of the abnormalities were attributed to frayed or split 

fins. Other lesions included body surface abnormalities and 

hemorrhagic eyes. These external lesions, liver abnormalities 

(nodules and focal discoloration), and kidney abnormalities 

(granular appearance and white nodules) were the main contributors of the inflated HAI scores (>130) of bass and were a 

result of helminth parasites and myxosporidian parasites. No 

reproductive biomarkers were anomalous in fish at Station 44. 

Lower Columbia River (LCR) 

Stations 46, 502, 506, 45, 505, and 501 were included in 

the LCR. Male and female largescale sucker were collected 

from all stations except Stations 45 and 502 where only female 

fish were collected. Carp were collected from Stations 45 

(male and female), 501 (male), and 502 (male and female). 

Male and female bass were collected from Stations 502, 505, 

and 45, and Station 506 had a single male bass. Female northern pikeminnow were collected from Station 46, 502, 505, and 

501; Station 501 was the only station where male northern 

pikeminnow were collected. All of the LCR stations were 

sampled in late November in 1997 except for Station 506 and 

501, which were sampled in early April 1998. 

Previously, the LCR has been the focus of many contaminant studies. Numerous water quality impairments due 

to nutrients, metals, p,p’-DDT, p,p’-DDE, dieldrin, phthalates, and PCBs have been reported in the LCR (ODEQ, 2000; 

USEPA, 2002b). Fish consumption advisories have been 

issued for p,p’-DDT, dioxins, and PCBs in all freshwater fish 

and for PCBs in shellfish and crayfish in the LCR. Specifically, the Willamette River has several fish consumption 

advisories for As, Hg, dioxins, organochlorinated pesticides, 

creosote, and PCBs (USEPA, 2003a). A previous study determined pesticides in water, dioxin, and metals in some sediment samples, and a host of organic and inorganic contaminants in the tissues of fish and wildlife were of concern from 

the mouth of the river to Bonneville Dam (LCREP, 1991). 

The Bi-State Water Quality Program found strong evidence 

that many of the contaminants present in the LCR had the 

potential to have negative effects on wildlife and sediments in 

select locations containing heavy metals, organochlorine pesticides, dioxins and furans and other organic compounds (Tetra 

Tech Inc., 1996). The NAWQA program also found many 

contaminants including PCBs, chlordane, p,p’-DDT, and Hg 

Results and Discussion 101 

were of concern in the LCR (Wentz and others, 1998; Wong 

and others, 2000). 

Station 46 (Cascade Locks, Oregon) 

Fish at Station 46 had a minimal number of contaminants 

and biomarkers of concern (Table 34). The concentration of 

Hg in female largescale sucker (0.13 μg/g ww) exceeded criteria shown to cause reproductive problems in mallards (Heinz, 

1979) (Fig. 28). Female largescale sucker also had concentrations of PCBs (0.13 μg/g ww) that exceeded the NYSDEC 

wildlife guideline of 0.11 μg/g ww, and a TCDD-EQ of 10 

pg/g exceeded the dietary threshold (5 pg/g) for avian wildlife (Nosek and others, 1992). Station mean EROD activity 

exceeded 10 pmol/min/mg for male (14.1 pmol/min/mg) and 

female (19.5 pmol/min/mg) largescale sucker indicating exposure to exogenous AhR agonists (Fig. 29). External lesions 

were identified on 81% of the largescale sucker from Station 

46. Most of these abnormalities were attributed to frayed or 

hemorrhagic fins, which may be an artifact of holding time 

after capture. Trace concentrations of vtg (0.02 mg/mL) were 

measured in male largescale sucker from Station 46 (Fig. 30). 

Station 502 (Warrendale, Oregon) 

Multiple contaminants and biomarkers were of concern 

in fish at Station 502 (Table 34). Contaminant analyses were 

not performed on largescale sucker from Station 502. Concentrations of Hg in female carp, male bass, and female northern 

pikeminnow exceeded criteria (0.1 μg/g ww) shown to cause 

reproductive problems in mallards (Heinz, 1979) (Fig. 28). 

Concentrations of PCBs in all fish exceeded the NYSDEC 

wildlife guideline of 0.11 μg/g ww (Newell and others, 1987). 

Dioxin-like activity (TCDD-EQ) was detected in all fish 

samples and exceeded the dietary threshold (5 pg/g) for avian 

wildlife (Nosek and others, 1992) in female carp and northern pikeminnow. EROD activity exceeded levels determined 

in the BEST 1995 MRB study for individual bass, carp, and 

largescale sucker, and the station means exceeded the criteria 

for male carp and female largescale sucker (Fig. 29). External 

lesions were the only fish health indicator to be highlighted in 

fish at Station 502. External lesions were identified on >84% 

of all fish examined with most lesions being attributed to 

frayed or hemorrhagic fins. Concentrations of vtg were >0.01 

mg/mL in three male carp (0.01-0.04 mg/mL) from Station 

502 (Fig. 30). These concentrations indicate that multiple 

male fish had an estrogenic response to environmental conditions at this station. In addition, two of three male bass had 

ovotestes, although other reproductive biomarkers (that is, GSI 

and vtg) for these individual fish appeared normal. The only 

other fish identified as having ovotestes were male bass from 

Station 42. 
102 Environmental Contaminants and their Effects on Fish 

Station 506 (Vancouver, Washington) 

Fish at Station 506 had a limited number of contaminants 

and biomarkers that were of concern (Table 34). The average 

concentration of Hg in male largescale sucker was 0.1 μg/g 

ww, a concentration shown to cause reproductive problems in 

mallards (Heinz, 1979) (Fig. 28). However, female largescale 

sucker had concentrations of Hg less than the criteria. Largescale sucker from Station 506 were the only samples that had 

toxaphene (0.05 μg/g ww), mirex (0.01 μg/g ww), and endrin 

(0.01 μg/g ww). The concentration of PCBs in female largescale sucker exceeded the NYSDEC wildlife guideline of 0.11 

μg/g ww (Newell and others, 1987) and was one of the highest 

concentrations (0.75 μg/g ww) measured in the CRB. The 

TCDD-EQ value for female largescale sucker also exceeded 

5 pg/g, the dietary threshold for avian wildlife (Nosek and 

others, 1992). External lesions were the only fish health 

indicator of concern at Station 506. External abnormalities 

were described in 76% of largescale sucker, with most lesions 

identified as body surface scars or hemorrhagic or frayed fins. 

No reproductive biomarkers were anomalous at Station 506. 

Station 45 (Oregon City, Oregon) 

Several contaminants and biomarkers in fish at Station 45 

were at concentrations or levels that were of concern (Table 

34). Concentrations of Hg in male and female bass, female 

carp, and female largescale sucker exceeded criteria (0.1 

μg/g ww) shown to cause reproductive problems in mallards 

(Heinz, 1979) but less than criteria (0.3 μg/g ww) shown to 

cause reproductive impairment in loons (Barr, 1986) (Fig. 

28). Concentrations of PCBs in bass and largescale sucker 

were less than protective criteria (0.11 μg/g ww), but male and 

female carp had concentrations >0.27 μg/g ww. Male bass and 

carp had TCDD-EQs that exceeded the dietary threshold for 

avian wildlife (5 pg/g) (Nosek and others, 1992). Mean station EROD activity exceeded levels for bass, carp, and largescale sucker (Schmitt and others, 2002b) (Fig. 29). The station 

mean EROD activity female carp (10.3 pmol/min/mg) was the 

greatest measured in the CRB. External lesions were identified on 87% of the fish collected from Station 45 with most 

abnormalities identified as body surface lesions and frayed 

fins. Bass were also identified as having multiple HAI scores 

>100. Many of these scores were attributed to abnormalities 

in the liver (nodules and discoloration), kidneys (nodules), and 

fins (frayed). The external lesions collected for histology, as 

well as nodules and discolored areas in the liver and spleen 

were a result of helminth parasites. Kidney lesions were due 

to helminth and myxosporidian parasites. Trace concentrations of vtg (0.01 mg/mL) were measured in male carp from 

Station 45 (Fig. 30). 

Station 505 (Portland, Oregon) 

Multiple contaminants and biomarkers were highlighted 

in fish at Station 505 (Table 34). Concentrations of Hg in 

bass and largescale sucker exceeded criteria (0.1 μg/g ww) 

known to cause reproductive problems in mallards (Heinz, 

1979). Concentrations of PCBs in bass and largescale sucker 

exceeded the NYSDEC wildlife guideline of 0.11 μg/g ww 

(Newell and others, 1987). TCDD-EQs in female bass and 

largescale sucker exceeded 5 pg/g, but male bass and largescale sucker did not exceed the dietary threshold for avian 

wildlife (Nosek and others, 1992). Bass and largescale sucker 

from Station 505 had the greatest mean station EROD activities determined in the CRB with individual EROD activities 

>50 pmol/min/mg. Over 75% of bass and largescale sucker 

were identified as having external lesions. Most of these 

abnormalities were defined as body surface lesions and frayed 

or hemorrhagic fins. These types of lesions are not necessarily 

indicative of exposure to environmental contaminants. Vitellogenin was the only reproductive biomarker of concern at 

Station 505 with male largescale sucker having trace concentrations of vtg (Fig. 30). 

Station 501 (Beaver Army Terminal, Oregon) 

Fish at Station 501 had few contaminants and one fish 

health indicator of concern (Table 34). All inorganic contaminants were less than criteria set to protect piscivorous 

fish and other wildlife. Concentrations of p,p’-DDE in male 

carp and male and female largescale sucker (>0.5 μg/g ww) 

exceeded several wildlife guidelines (Anderson and others, 

1975; Jarvinen and Ankley, 1999; Newell and others, 1987). 

Concentrations of PCBs in male carp, male largescale sucker, 

and female northern pikeminnow exceeded the NYSDEC 

wildlife guideline of 0.11 μg/g ww (Newell and others, 1987). 

A female northern pikeminnow was the only sample to have 

a TCDD-EQ that exceeded 5 pg/g, the dietary threshold for 

avian wildlife (Nosek and others, 1992). Most carp (100%), 

largescale sucker (82%), and northern pikeminnow (92%) 

from Station 501 were identified as having external lesions. 

These abnormalities were categorized as frayed fins in most 

fish, a condition that may be associated with holding time 

prior to fish processing. Reproductive indicators were not at 

levels or concentrations of concern at Station 501. 

Correlations Between Contaminant 

Concentrations and Biological Endpoints 

Spearman Rank correlations were examined to determine 

if chemical concentrations were related to biomarker responses 

in the CRB (Table 35). Correlations are reported for each 

gender and species. Ideally the analysis would only include 

samples above known levels of concerns for both chemical 

concentrations and biomarker responses. The limited sample 
Summary and Conclusions 103 

Table 35. Statistically significant Spearman Rank correlations (P <0.05) between biomarkers and contaminants. See text for biomarker 

definitions. 1

Black text, positive correlations; red text, negative correlations. 2Genders were not combined in this analysis because 

many biomarker differed between males and females. 3Percent atresia was measured in females only. Samples <LOD and samples 

sizes <5 were excluded from this analysis. m, male; f, female; b, bass; c, carp; s, largescale sucker. 

Biomarker1, 2 Total DDT PCBs TCDD-EQ Cd Cr Cu Fe Hg Pb Se Zn 

Age fc, ms fs fb 

Total Length fc fs fs, ms 

Weight fc mc fs, ms 

Condition Factor mb mc mc 

SSI ms fc fb, mb fb fc, fs 

HSI mb 

GSI mb ms 

MEANAREA mb mc ms fc 

MAMM mc fc, mc 

TISSOC fc mc mc 

Atresia3 fc fb 

HAI mb ms ms ms mb fc fs 

Vtg mb, fc 

EROD fb 

size of the CRB data does not allow for this inclusion. Contaminant and biomarker data <LOD and with sample sizes less 

than were excluded from the analysis. Multiple biomarker 

responses were found to be correlated with contaminant 

concentrations, but few correlations were present in more 

than one species, genders, or both (Table 35). These correlations are difficult to interpret because many of them cannot 

be readily explained from a contaminant aspect, and expected 

correlations (that is, EROD and PCBs or TCDD-EQ) were not 

significant. This may be due to the limited sample size of this 

study. In the future, this monitoring program hopes to combine data from all BEST projects and further explore correlations of biomarker responses to contaminant concentrations. 

Summary and Conclusions 

Overall, fish from the MCR and LCR had greater concentrations of organochlorine contaminants (total p,p’-DDT, 

PCBs) than fish from the UCR. These results are consistent 

with other studies from the CRB. PCBs and p,p’-DDE were 

the only contaminants where temporal trends could be evaluated. Concentrations of PCBs had declining trends in fish 

samples at all stations where data were available. This pattern 

was not reflected for p,p’-DDE which remained fairly consistent from 1969 to 1997. Except for Hg, Se, and Pb, concentrations of elemental contaminants were relatively low and stable 

or declining relative to historical levels in fish samples at most 

sites. Concentrations of Hg were elevated in bass and northern 

pikeminnow from the Salmon River at Riggins, Idaho (Station 

43) and from several other sites including Granger, Washington (Station 44) and Cascade Locks, Oregon (Station 46). 

Concentrations of Pb in largescale sucker remained comparable to high historical concentrations near Northport, Washington (Station 504) and Grand Coulee, Washington (Station 

98), stations located downstream from a Pb smelter located in 

British Columbia. Concentrations of Se in fish also remained 

high enough to constitute a hazard to piscivorous wildlife at 

Riggins, Idaho (Station 43), Vernita Bridge, Washington (Station 503), and Pasco, Washington (Station 97). Elevated concentrations of Se near Pasco, Washington had been reported 

previously. 

Concentrations of PCBs and TCDD-EQ were low in most 

CRB samples, but EROD rates in bass, carp, and largescale 

sucker exceeded threshold levels reported in the 1995 BEST 

MRB report (Schmitt and others, 2002b) and reflected exposure to exogenous AhR ligands at most sites. These results 

indicate that fish from some CRB sites were likely exposed 

to EROD-inducing chemicals other than PCBs, dioxins, and 

furans. A number of PAHs are known inducers of EROD 

activity, and some can have increased toxicity following 

CYP1A metabolism. However, the EROD activities measured 

in most CRB fish were low relative to levels reported in bass 

and carp from other river basins in the U.S. (Schmitt and others, 2002b; Whyte and others, 2000). 

Discernable spatial patterns of contaminant exposure 

were not evident in the CRB; however, results at specific stations indicate that fish throughout the CRB were exposed to a 

variety of contaminants. The enlarged spleens and prevalence 

of external lesions (excluding fin abnormalities) in the fish 

from the UCR suggest that the fish were diseased, possibly 

as a consequence of immune suppression caused by chemical 

exposure (Anderson and others, 1989; Hutchinson and Manning, 1996), but other factors such as age, size, growth rate, 

and gonadal development may have been involved (Krykhitin, 

1976; Ruklov, 1979). Many of the external lesions were proliferative responses of epidermal or mucous cells in the epidermis or inflammatory responses in the dermis due to parasites 

or undetermined causes. Many of the internal abnormalities 

were due to helminth or myxosporidian parasites. Immune 

suppression could play a role in these infections, however the 
104 Environmental Contaminants and their Effects on Fish 

presence and density of intermediate hosts in an ecosystem is 

also an important factor. Enlarged livers were found in female 

bass at Vernita, Washington (Station 503). The relatively 

small spleen size of fish from stations throughout the CRB is a 

condition that has been associated with exposure to a number 

of different chemicals including petroleum products and metals (Schmitt and Dethloff, 2000). Male bass with ovotestes 

were found at the Snake River near Lewiston, Idaho (Station 

42) and Columbia River near Warrendale, Oregon (Station 

502). Similar ovotestes have been induced in males of other 

species exposed to organochlorine pesticides, natural and synthetic estrogens, and sewage in controlled laboratory and field 

studies although many factors may be involved (Jobling and 

others, 1998; Purdom and others, 1994; Wester and Canton, 

1986). The incidence of ovotestes may have been underestimated by examining only a small proportion of the gonad of 

each fish. Male bass, carp, and largescale sucker containing 

low concentrations of vtg were relatively common, but males 

with comparatively high concentrations of vtg (that is, levels 

typical of early- mid-vitellogenic females) were also collected 

from Creston, Montana (Station 117), Grand Coulee, Washington (Station 98), and Pasco, Washington (Station 97). Biomarkers can be induced in fish by exposure to contaminants 

although a wide variety factors can cause these conditions (see 

reviews in Schmitt and Dethloff, 2000). 

Multiple species representing various trophic levels 

should be included in biomonitoring programs. Previous 

studies have found that chemical accumulation and biomarker 

patterns are species specific. Bass, carp, and largescale sucker 

from the CRB varied in contaminant accumulation and levels 

of effect for biomarkers in the present study. Concentrations 

of Hg in the CRB accumulated more in bass than in carp and 

sucker as reported in other studies (Schmitt and others, 2002b; 

2004). Conversely, carp and sucker had greater concentrations of Cd, Cu, Cr, and Ni compared to bass, and concentrations of Zn in carp were consistently four to five times greater 

than other species. Concentrations of pesticides were similar 

among bass, carp, and largescale sucker. EROD activities in 

carp were less than in bass and sucker throughout the CRB. 

Condition factor was greatest in bass and lowest in sucker, 

whereas SSI was lower bass than carp and sucker. Macrophage aggregate were similar in bass, carp, and sucker in the 

CRB in 1997. For reproductive indicators, GSI and atresia 

were greater in carp than in bass and sucker. However, vtg 

was much greater in sucker than in bass or carp. Results from 

this study demonstrate that evaluating multiple species from 

different levels of the food chain allows for a better understanding of how environmental contaminants affect biota. 

Results from this study also suggest that continued monitoring 

is warranted in the CRB. Various sites within the basin had 

concentrations that are potentially problematic to wildlife. 

Focused investigations are needed to further define contaminants and their effects on fish in the CRB. 

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Appendix 1 119


Appendix 1.

d 

Appendix 1. Lengths, weights, and ages of non-target species collected in the Columbia River Basin in 1997. Stations are grouped by sub-basin and listed upstream to 

downstream. Station numbers are given in parentheses. Sample size (n), arithmetic mean, standard deviation (SD), and range are also given. Fish in which gender could not be determined are identified as having no gonad (NG) or juveniles (J).—Continue 

Sub-basin and Length (mm) Weight (g) Age (years) 

Station Taxa Gender n Mean SD Range n Mean SD Range n Mean SD Range 

Entire Basin Northern All 58 444 

pikeminnow F 48 457 

M 10 382 

69.6 322-582 58 829 374 263-1624 49 8.7 2.33 5-14 

68.6 327-582 48 885 379 263-1624 41 9.1 2.19 6-14 

28.7 322-425 10 558 192 300-900 8 6.6 0.92 5-8 

Longnose All 15 404 65.0 296-505 15 705 323 233-1326 15 4.1 0.70 3-6 sucker F 11 416 51.6 331-505 

M 2 443 73.5 391-495 

NG 2 298 2.8 296-300 

11 744 251 361-1176 11 4.1 0.70 3-6 

2 938 549 550-1326 2 4.5 0.71 4-5 

2 255 30 233-276 2 3.5 0.71 3-4 

Rainbow trout All 20 387 104 

F 10 375 111 

M 2 504 50.9 

NG/J 8 374 92.6 

235-540 20 660 460 125-1576 20 2.2 1.04 1-5 

235-533 10 646 529 125-1576 10 2.5 1.18 1-5 

468-540 2 1084 250 907-1260 2 2.5 0.71 2-3 

238-490 8 571 380 125-1103 8 1.6 0.74 1-3 

Walleye All 17 370 49.3 

F 9 376 55.8 

M 4 396 21.4 

NG/J 4 329 30.5 

297-505 17 455 282 208-1428 17 2.5 0.80 2-5 

313-505 9 487 367 208-1428 2.6 2.5 1.01 2-5 

372-423 4 493 41 444-541 4 2.5 0.58 2-3 

297-368 4 344 209 214-652 4 2.5 0.58 2-3 

Upper Columbia River (UCR)Creston, MT Longnose F 10 411 (117) sucker M 1 495 

NG 2 298 

52.0 331-505 10 730 260 361-1176 10 4.1 0.74 3-6 

-- -- 1 1326 -- -- 1 5.0 -- --

2.8 296-300 2 255 30 233-276 2 3.5 0.71 3.4 

Northport, WA Rainbow trout F 10 375 

(504) M 2 504 

J 8 374 

Grand Coulee, Walleye F 8 360 

WA (98) M 4 396 

J 4 329 

111 235-533 10 646 529 125-1576 10 2.5 1.18 1-5 

50.9 468-540 2 1084 250 907-1260 2 2.5 0.71 2-3 

92.6 238-490 8 571 380 125-1103 8 1.6 0.74 1-3 

29.8 313-407 8 369 106 208-544 8 2.3 0.46 2-3 

21.4 372-423 4 455 41 208-1428 4 2.5 0.58 2-3 

30.5 297-368 4 344 209 214-652 4 2.5 0.58 2-3 

Longnose F 1 462 -- -- 1 889 -- -- 1 4.0 -- --sucker M 1 391 -- -- 1 550 -- -- 1 4.0 -- --

Snake River (SR) Riggins, ID Northern F 9 406 37.7 347-464 9 655 230 275-975 8 7.8 1.28 6-10 (43) pikeminnow M 5 367 25.3 322-385 5 600 245 300-900 4 6.8 0.96 6-8 

120 Environmental Contaminants and their Effects on Fish 
Appendix 1. Lengths, weights, and ages of non-target species collected in the Columbia River Basin in 1997. Stations are grouped by sub-basin and listed upstream to 

downstream. Station numbers are given in parentheses. Sample size (n), arithmetic mean, standard deviation (SD), and range are also given. Fish in which gender could not be determined are identified as having no gonad (NG) or juveniles (J).—Continued 

Sub-basin and Length (mm) Weight (g) Age (years) 

Station Taxa Gender n Mean SD Range n Mean SD Range n Mean SD Range 

Middle Columbia River (MCR)Vernita Bridge, Northern F 8 488 31.6 438-532 8 1039 181 785-1232 8 10.6 1.41 9-13 

WA (503) pikeminnow M 2 423 3.5 420-425 2 652 49 617-687 2 7.0 0.00 7 

Granger, WA Northern F 5 413 58.5 327-491 5 601 267 263-1005 5 6.8 1.10 6-8 (44) pikeminnow M 1 371 -- -- 1 419 -- -- 1 5.0 -- --Lower Columbia River (LCR) Cascade Locks, Northern F 2 541 12.0 532-549 2 1479 94 1411-1546 1 8.0 -- --OR (46) pikeminnow Warrendale, Northern F 11 514 39.0 377-582 11 1143 401 432-1624 10 11.0 2.50 6-14 

OR (502) pikeminnow

Portland, OR Northern F 2 363 17.7 350-375 2 371 46 338-403 0 -- -- --(505) pikeminnow

Walleye F 1 505 -- -- 1 1428 -- -- 1 5.0 -- --

Beaver Army Northern F 11 442 55.1 356-531 11 819 332 325-1386 10 8.7 1.34 7-11 Terminal, OR pikeminnow M 2 384 16.3 372-395 2 430 98 360-499 2 7.0 0.00 7 (501) 

Appendix 1 121

122 Environmental Contaminants and their Effects on Fish 
Appendix 2 123


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124 Environmental Contaminants and their Effects on Fish 

Appendix 2. Fish health indicators for non-target species collected in the Columbia River basin in 1997. Arithmetic 

mean, number of samples (n ), minimum (min.), maxiumum (max.), and standard error (SE) are given for gonadosomatic 

index (GSI; %), splenosomatic index (SSI; %), condition factor (CF), and health assessment index (HAI). Stations are 

grouped by taxon and ordered upstream to downstream. Fish with undetermined gender from which no gonad was 

obtained are listed as juvenile. 

Taxon and Female Male Juvenile 

Station n Mean Min. Max. SE n Mean Min. Max. SE n Mean Min. Max. SE 

Northern pikeminnow 

Riggins, ID (43) 

GSI 9 2.44 1.71 3.42 0.2 5 0.51 0.31 0.82 0.1 0 

SSI 9 0.11 0.08 0.17 0.0 5 0.10 0.05 0.16 0.0 0 

CF 9 0.94 0.59 1.04 0.0 5 1.19 0.88 1.67 0.2 0 

HAI 9 52.2 30 70 4.9 5 64.0 30 120 19.1 0 

Vernita Bridge, WA (503) 

GSI 8 2.63 2.01 3.46 0.2 2 0.67 0.66 0.67 0.0 0 

SSI 8 0.16 0.11 0.25 0.0 2 0.19 0.18 0.19 0.0 0 

CF 8 0.89 0.79 1.00 0.0 2 0.87 0.80 0.93 0.1 0 

HAI 8 47.5 10 100 9.6 2 30.0 30 30 0.0 0 

Granger, WA (44) 

GSI 5 1.83 0.66 2.42 0.3 1 0.82 0 

SSI 5 0.17 0.13 0.26 0.0 1 0.17 0 

CF 5 0.80 0.75 0.85 0.0 1 0.82 0 

HAI 5 130.0 100 160 9.5 1 130 0 

Cascade Locks, OR (46) 

GSI 2 3.23 3.18 3.28 0.1 0 0 

SSI 2 0.31 0.25 0.36 0.1 0 0 

CF 2 0.94 0.85 1.03 0.1 0 0 

HAI 2 5.0 0 10 5.0 0 0 

Warrendale, OR (502) 

GSI 11 3.21 2.02 6.27 0.3 0 0 

SSI 11 0.14 0.09 0.19 0.0 0 0 

CF 11 0.81 0.50 1.01 0.0 0 0 

HAI 11 90.0 10 160 11.7 0 0 

Portland, OR (505) 

GSI 2 1.21 1.07 1.35 0.1 0 0 

SSI 2 0.12 0.11 0.13 0.0 0 0 

CF 2 0.78 0.76 0.79 0.0 0 0 

HAI 2 85.0 70 100 15.0 0 0 

Beaver Army Terminal, OR (501) 

GSI 11 4.14 2.40 6.58 0.4 2 1.43 1.09 1.78 0.3 0 

SSI 11 0.15 0.10 0.19 0.0 2 0.20 0.18 0.22 0.0 0 

CF 11 0.89 0.70 0.96 0.0 2 0.75 0.70 0.81 0.1 0 

HAI 11 66.4 0 130 9.5 2 50.0 30 70 20.0 0 

Walleye 

Grand Coulee, WA (98) 

HSI 8 0.77 0.61 0.98 0.0 4 0.65 0.46 0.85 0.1 4 0.97 0.44 1.58 0.2 

GSI 8 0.36 0.28 0.46 0.0 4 3.47 3.11 3.78 0.1 4 0.04 0.02 0.05 0.0 

SSI 8 0.07 0.05 0.09 0.0 4 0.07 0.04 0.09 0.0 4 0.06 0.04 0.08 0.0 

CF 8 0.77 0.68 0.84 0.0 4 0.80 0.71 0.86 0.0 4 0.90 0.68 1.31 0.1 

HAI 8 18.8 0 60 7.9 4 27.5 0 70 15.5 4 30.0 0 60 12.2 

Portland, OR (505) 

HSI 1 1.71 0 0 

GSI 1 0.32 0 0 

SSI 1 0.11 0 0 

CF 1 1.11 0 0 

HAI 1 30 0 0 
Appendix 2 125 

Appendix 2. Fish health indicators for non-target species collected in the Columbia River basin in 1997. Arithmetic 

mean, number of samples (n ), minimum (min.), maxiumum (max.), and standard error (SE) are given for gonadosomatic 

index (GSI; %), splenosomatic index (SSI; %), condition factor (CF), and health assessment index (HAI). Stations are 

grouped by taxon and ordered upstream to downstream. Fish with undetermined gender from which no gonad was 

obtained are listed as juvenile.—Continued 

Taxon and Female Male Juvenile 

Station n Mean Min. Max. SE n Mean Min. Max. SE n Mean Min. Max. SE 

Longnose sucker 

Creston, MT (117)

GSI 10 6.50 0.59 12.40 1.4

SSI 10 0.28 0.14 0.39 0.0

CF 10 1.01 0.91 1.11 0.0

HAI 10 35.0 0 90 10.2

Grand Coulee, WA (98)

GSI 1 7.76 -- -- --

SSI 1 0.27 -- -- --

CF 1 0.90 -- -- --

HAI 1 30 -- -- --

NG 

1 5.35 -- -- -- 2 0.21 0.16 0.25 0.0 

1 0.33 -- -- -- 2 0.15 0.02 0.27 0.1 

1 1.09 -- -- -- 2 0.96 0.90 1.02 0.1 

1 30 -- -- -- 2 0 0 0 0.0 

1 5.24 -- -- -- 0 -- -- -- --

1 0.36 -- -- -- 0 -- -- -- --

1 0.92 -- -- -- 0 -- -- -- --

1 100 -- -- -- 0 -- -- -- --

Rainbow trout 

Northport, WA (504)

HSI 10 1.02 0.67 1.40 0.1

GSI 10 1.95 0.05 7.10 0.9

SSI 10 0.10 0.02 0.30 0.0

CF 10 0.98 0.86 1.17 0.0

HAI 10 24.0 0 70 9.8

2 0.86 0.80 0.92 0.1 8 0.80 0.67 0.96 0.0 

2 4.79 4.44 5.14 0.3 8 0.03 0.01 0.07 0.0 

2 0.11 0.10 0.12 0.0 8 0.07 0.05 0.10 0.0 

2 0.84 0.80 0.88 0.0 8 0.93 0.72 1.02 0.0 

2 45.0 30 60 15.0 8 16.3 0 60 7.8 
126 Environmental Contaminants and their Effects on Fish 
(BEST) Program: Environmental Contaminants and their Effects on Fish in the Columbia River Basin—USGS/SIR 2004—5154

i l

Hinck. J.E.; Schmitt, C.J.; Bartish, T.M.; Denslow, N.D.; Blazer, V.S.; Anderson, P.J.; Coyle, J.J.; Dethloff, G.M; Tillitt, D.E.—Biomonitoring of Environmental Status and Trends 

Pr nted on recyc ed paper