U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2007–5222

Prepared in cooperation with the Indiana Department of Environmental Management, 

Division of Water, Assessment Branch

Relations of Principal Components Analysis Site Scores to 

Algal-Biomass, Habitat, Basin-Characteristics, Nutrient, and 

Biological-Community Data in the West Fork White River 

Basin, Indiana, 2001

Relations of Principal Components 

Analysis Site Scores to Algal-Biomass, 

Habitat, Basin-Characteristics, Nutrient, 

and Biological-Community Data in the 

West Fork White River Basin, Indiana, 2001

By Jeffrey W. Frey, Brian J. Caskey, and B. Scott Lowe

Prepared in cooperation with the Indiana Department of Environmental 

Management, Division of Water, Assessment Branch

Scientific Investigations Report 2007–5222

U.S. Department of the Interior

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

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2007

For product and ordering information:

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

Telephone: 1-888-ASK-USGS

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment:

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

Telephone: 1-888-ASK-USGS

Any use of trade, product, or firm names 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:

Frey, J.W., Caskey, B.J., and Lowe, B. S., 2007, Relations of Principal Component Analysis site scores algal-biomass, 

habitat, basin-characteristics, nutrient, and biological community data in the West Fork White River Basin, Indiana, 

2001: U.S. Geological Survey Scientific Investigations Report 2007–5222, 25 p.
iii

Contents

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

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

Purpose and Scope ..............................................................................................................................2

Description of the West Fork White River Basin.............................................................................3

Study Methods ...............................................................................................................................................3

Site Selection and Sampling Strategies ...........................................................................................3

Algal-Biomass, Habitat, Nutrient, and Biological-Community Data-Collection and 

Processing Methods ..............................................................................................................3

Data Analysis.........................................................................................................................................7

Basin-Characteristics Data........................................................................................................8

Nutrient Data ................................................................................................................................8

Principal Components Analysis.................................................................................................8

Comparison With U.S. Environmental Protection Agency Data .........................................9

Relations of the Principal Components Analysis Site Scores to Algal-Biomass, Habitat, 

Basin-Characteristics, Nutrient, and Biological-Community Data ............................................

.............................................................................................................................................................9

Drainage-Area and Land-Use Analysis ..................................................................................................11

Comparison of the Data to Ecoregion Nutrient Criteria ........................................................................15

Conclusions...................................................................................................................................................21

Acknowledgments.......................................................................................................................................21

References....................................................................................................................................................21

Appendix 1.....................................................................................................................................................24

Figures

1. Map showing location of the 34 algal-biomass sampling sites in West Fork 

White River Basin, Indiana, 2001................................................................................................4

2. Graphs showing the percentage of drainage area and agricultural, forest, and 

urban land use in the West Fork White River Basin, Indiana, 2001....................................12

Tables

1. Location and basin characteristics of the 34 algal-biomass sampling sites in the 

West Fork White River Basin, Indiana, July through September 2001. ...............................5

2. Significant Spearman’s rho relations of the yearly periphyton Principal 

Components Analysis axis 1 site scores (PC1) to algal biomass, habitat, basin 

characteristics, and nutrients and fish- and invertebrate-community attributes 

and metric scores, 2001.............................................................................................................10

3. Significant Spearman’s rho relations of the yearly seston Principal 

Components Analysis axis 1 site scores (PC1) to algal biomass, habitat, basin 

characteristics, and nutrients and fish- and invertebrate-community attributes 

and metric scores, 2001............................................................................................................11
iv

4. Basin characteristics of the 34 algal-biomass sampling sites in the West Fork 

White River Basin, Indiana, July through September 2001. ................................................13

 5. Total Kjeldahl nitrogen as N values collected in 2001 from the Indiana Department 

of Environmental Management/U.S. Geological Survey study and the published 

U.S. Environmental Protection Agency values for Aggregate Nutrient Ecoregions 

VI and IX and Level III Ecoregions 55 and 72. ........................................................................15

6. Nitrite plus nitrate as N values collected in 2001 from the Indiana Department of 

Environmental Management/U.S. Geological Survey study and the published 

U.S. Environmental Protection Agency values for Aggregate Nutrient Ecoregions 

VI and IX and Level III Ecoregions 55 and 72. ........................................................................16

7. Total nitrogen as N values collected in 2001 from the Indiana Department of 

Environmental Management/U.S. Geological Survey study and the published 

U.S. Environmental Protection Agency values for Aggregate Nutrient Ecoregions 

VI and IX and Level III Ecoregions 55 and 72. ........................................................................17

8. Total phosphorus as P values collected in 2001 from the Indiana Department of 

Environmental Management/U.S. Geological Survey study and the published 

U.S. Environmental Protection Agency values for Aggregate Nutrient Ecoregions 

VI and IX and Level III Ecoregions 55 and 72. ........................................................................18

9. Mean periphyton chlorophyll a values collected in 2001 from the Indiana 

Department of Environmental Management/U.S. Geological Survey study and 

the published U.S. Environmental Protection Agency values for Aggregate 

Nutrient Ecoregions VI and IX and Level III Ecoregions 55 and 72. ...................................19

10. Mean seston chlorophyll a values collected in 2001 from the Indiana 

Department of Environmental Management/U.S. Geological Survey study and 

the published U.S. Environmental Protection Agency values for Aggregate 

Nutrient Ecoregions VI and IX and Level III Ecoregions 55 and 72. ...................................20
v

Multiply By To obtain

centimeter (cm) 0.3937 inch (in.)

square kilometer (km2) 0.3861 square mile (mi2)

cubic meter per second (m3/s) 35.31 cubic foot per second (ft3/s)

liter (L) 0.2642 gallon (gal)

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

°F=(1.8×°C)+32

Horizontal coordinate information used in the map is referenced to the North American Datum 

of 1927 (NAD 27). Sampling-site coordinate information used a Global Positioning System (GPS) 

referenced to North American Datum of 1983 (NAD 83), which then was converted to NAD 27.

Concentrations of chemical and algal-biomass constituents in water are given either in 

milligrams per liter (mg/L) or micrograms per liter (μg/L). Concentrations of periphyton algal 

biomass are given in milligrams per meter squared (mg/m2).

Conversion Factors and Datum
vi

Abbreviations 

Abbreviations and acronyms used in this report:

PC1 Principal components analysis first axis site score

EPT Ephemeroptera, Plecoptera, and Trichoptera

USEPA U.S. Environmental Protection Agency

N nitrogen

P phosphorus

CWA Clean Water Act

IBI Index of Biotic Integrity

TN total nitrogen

TP total phosphorus

CHLa chlorophyll a

TKN total Kjeldahl nitrogen

IDEM Indiana Department of Environmental Management

USGS U.S. Geological Survey

WMP Watershed Monitoring Program

PCA Principal components analysis

AFDM ash-free dry mass

POC particulate organic carbon

IN Indiana

NAWQA National Water-Quality Assessment Program

NWQL National Water Quality Laboratory

QHEI Qualitative Habitat Evaluation Index

NLCD National Land Cover Dataset

r

s

 Spearman’s rho statistic
Abstract 

Data were gathered from July through September 2001 

at 34 randomly selected sites in the West Fork White River 

Basin, Indiana for algal biomass, habitat, nutrients, and biological communities (fish and invertebrates). Basin characteristics (drainage area and land use) and biological-community 

attributes and metric scores were determined for the basin of 

each sampling site. Yearly Principal Components Analysis site 

scores were calculated for algal biomass (periphyton and seston). The yearly Principal Components Analysis site scores for 

the first axis (PC1) were related, using Spearman’s rho, to the 

seasonal algal-biomass, basin-characteristics, habitat, seasonal 

nutrient, biological-community attribute and metric score data. 

The periphyton PC1 site score, which was most influenced by ash-free dry mass, was negatively related to one (percent closed canopy) of nine habitat variables examined. Of the 

43 fish-community attributes and metric scores examined, the 

periphyton PC1 was positively related to one fish-community 

attribute (percent tolerant). Of the 21 invertebrate-community 

attributes and metric scores examined, the periphyton PC1 was 

positively related to one attribute (Ephemeroptera, Plecoptera, 

and Trichoptera (EPT) index) and one metric score (EPT index 

metric score). The periphyton PC1 was not related to the five 

basin-characteristic or 12 nutrient variables examined. The 

seston PC1 site score, which was most influenced by particulate organic carbon, was negatively related to two of the 12 

nutrient variables examined: total Kjeldahl nitrogen (July) and 

total phosphorus (July). Of the 43 fish-community attributes 

and metric scores examined, the seston PC1 was negatively 

related to one attribute (large-river percent). Of the 21 invertebrate-community attributes and metric scores examined, the 

seston PC1 was negatively related to one attribute (EPT-tototal ratio). The seston PC1 was not related to the five basincharacteristics or nine habitat variables examined.

To understand how the choice of sampling sites might 

have affected the results, an analysis of the drainage area and 

land use was done. The 34 randomly selected sites in the West 

Fork White River Basin in 2001 were skewed to small streams. 

The dominant mean land use of the sites sampled was agriculture, followed by forest, and urban. 

The values for nutrients (nitrate, total Kjeldahl nitrogen, 

total nitrogen, and total phosphorus) and chlorophyll a (periphyton and seston) were compared to published U.S. Environmental Protection Agency (USEPA) values for Aggregate 

Nutrient Ecoregions VI and IX and Level III Ecoregions 55 

and 72. Several nutrient values were greater than the 25th

percentile of the published USEPA values. Chlorophyll a

(periphyton and seston) values were either greater than the 

25th percentile of published USEPA values or extended data 

ranges in the Aggregate Nutrient Ecoregions and Level III 

Ecoregions. If the proposed values for the 25th percentile were 

adopted as nutrient water-quality criteria, many samples in 

the West Fork White River Basin would have exceeded the 

criteria.

Introduction

Excessive inputs of nutrients into streams have humanhealth, economic, and ecological consequences. Excess 

amounts of nutrients—nitrogen (N) and phosphorus (P)—have 

been shown to be a source of eutrophication in aquatic ecosystems, which sometimes has been linked to fish kills, shifts in 

species composition, taste and odor in drinking-water supplies, and blooms of harmful algae in freshwater and estuaries 

(Munn and Hamilton, 2003; U.S. Environmental Protection 

Agency, 2000a,b).

The Clean Water Act (CWA) established a national goal 

of achieving water quality that provides for the protection and 

propagation of aquatic organisms and wildlife, and recreation 

in and on the water. In 1996, the U.S. Environmental Protection Agency’s (USEPA) National Water Quality Inventory 

identified excess amounts of nutrients as the second leading 

cause of impairment in rivers and streams across the United 

States (the first cause was siltation) (U.S. Environmental 

Relations of Principal Components Analysis Site Scores to 

Algal-Biomass, Habitat, Basin-Characteristics, Nutrient, 

and Biological-Community Data in the West Fork White 

River Basin, Indiana, 2001

By Jeffrey W. Frey, Brian J. Caskey, and B. Scott Lowe
2 Relation of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

Protection Agency, 1997a). The excess amounts of nutrients 

that have been documented in many rivers and streams have 

resulted in streams that do not meet the goal of the CWA in 

Indiana and the nation.

USEPA drinking-water criteria (maximum contaminant 

levels) are 10 mg/L for nitrate as N and 1 mg/L nitrite as N 

(U.S. Environmental Protection Agency, 2005). In addition, 

aquatic-life criteria established to protect aquatic organisms 

have been set for ammonia as N (the ammonia as N aquaticlife criteria varies with pH, temperature, and life-stage) (U.S. 

Environmental Protection Agency, 2005). These criteria do 

not address the effects on the biological communities resulting from increased nutrients in rivers and streams. Typically, 

nutrient concentrations must be extremely high to be toxic to 

biological communities; such concentrations rarely are found 

in the environment (Ohio Environmental Protection Agency, 

1999). For example, nitrate as N concentrations below 90 mg/L 

would not have direct effects on warmwater fish. Exceptions 

are concentrations of ammonia after accidental discharges 

from wastewater-treatment facilities, combined-sewer overflows, or confined-animal feedlots (Ohio Environmental 

Protection Agency, 1999). Previous analysis of the effects of 

nutrients on biological communities in Ohio found few relations between nutrients and fish and invertebrate-community 

data (Miltner and Rankin, 1998). Only total phosphorus was 

significantly correlated with any of the fish or invertebrate 

attributes or metrics (fish Index of Biotic Integrity [IBI] scores 

in headwater streams). 

Many streams have been placed by the USEPA on the 

CWA Section 303(d) list of impaired water bodies because of 

excess amounts of nutrients. In 2000, the USEPA proposed 

nutrient water-quality criteria for causal variables—total 

nitrogen (TN) and total phosphorus (TP)—and for response 

variables—periphyton and seston chlorophyll a (CHLa) and 

turbidity. Criteria also have been proposed for nitrate and total 

Kjeldahl nitrogen (TKN) because TN is the sum of nitrate 

and TKN. These proposed nutrient water-quality criteria are 

based on Aggregate Nutrient Ecoregions, areas with similar 

geographic features (topography, soils, geology, land use, 

and biogeography) (U.S. Environmental Protection Agency, 

2000a,b). USEPA reviewed selected data and set the proposed 

nutrient water-quality criteria for nitrate, TKN, TN, TP, CHLa 

(periphyton and seston), and turbidity at the 25th-percentile 

value of all data for each parameter.

USEPA mandated that by 2004 states either accept the 

proposed nutrient water-quality criteria or provide their own 

set of criteria that are more appropriate to the waters within 

each state (U.S. Environmental Protection Agency, 2000a,b). 

An extension was given to Indiana and other states that 

adopted plans describing the data needs and the process to 

develop nutrient water-quality criteria. Beginning in 2001, the 

Indiana Department of Environmental Management (IDEM) 

and the U.S. Geological Survey (USGS) are cooperating on 

several studies that will assist the State of Indiana in developing nutrient water-quality criteria as mandated by the USEPA. 

The multivariate approach used in this report should allow the 

results to be used in similar ecoregions in Illinois and Ohio.

Purpose and Scope

Data in this report were collected as part of an ongoing 

cooperative effort between IDEM and the USGS in which 

similar studies have been conducted as part of the IDEM 

probabilistic Watershed Monitoring Program (WMP) in the 

Whitewater River and East Fork White River Basins (2002), 

Upper Wabash River Basin (2003), Lower Wabash River and 

Kankakee River Basins (2004), and Ohio River and Great 

Lakes Basins (2005) (Indiana Department of Environmental 

Management, 2001). In all of these yearly WMP studies, 

IDEM collected habitat and biological-community data and 

the nutrient data from 2001 through 2003; to augment the 

IDEM WMP studies and better understand nutrient enrichment 

in streams, the USGS collected algal biomass during all years 

of the study and also collected nutrients in 2004 and 2005. The 

long-term goal of these studies is to provide data and analysis 

to aid IDEM in the development of nutrient water-quality criteria. An objective of this report was to develop a preliminary 

understanding of how algal biomass relates to biological community and environmental variables in the West Fork White 

River Basin in 2001. In this report, the environmental vari

ables included nutrients, habitat, and basin characteristics. 

An additional purpose of this report was to compile a list of 

the most statistically significant relations between algal biomass, nutrients, habitat, and biological attributes and metrics 

that may be helpful in future investigations.

Two approaches were used for the preliminary analysis 

of the data sets. The first approach included ordination and 

regression analyses of the algal biomass, nutrient, and environmental data. The second approach compared the CHLa 

and nutrient values collected by IDEM and USGS personnel 

to USEPA published values. The purpose of this preliminary 

analysis was to investigate all potential relations and identify 

those relations that were the strongest and warrant further 

investigation. 

This report discusses the relations of yearly Principal 

Components Analysis (PCA) site axis scores, which represent algal biomass (periphyton and seston), to habitat, basin 

characteristics, nutrient, and biological-community (fish 

and invertebrates) attributes and metric scores (appendix 1; 

Dufour, 2002). Data were collected at 34 randomly selected 

sites in the West Fork White River Basin in 2001. A discussion of the basin characteristics of the 34 sites describes how 

drainage area and land use affect the analysis. This report 

also compares nutrient values (nitrate plus nitrite as N, TKN 

as N, TN as N, TP as P) and CHLa (periphyton and seston) 

collected by IDEM and USGS for the West Fork White River 

Basin to values published by the USEPA for both Aggregate 

Nutrient Ecoregions (VI, Corn Belt and Northern Great Plains; 

IX, Southeastern Temperate Forested Plains and Hills) (U.S. 

Environmental Protection Agency, 2000a,b) and for Level III 
Study Methods 3

Ecoregions (55, Eastern Corn Belt Plains; 71, Interior Plateau; 

and 72, Interior River Lowland) (U.S. Environmental Protection Agency, 1997b). Aggregate Nutrient Ecoregions consist 

of one or more Level III Ecoregions (U.S. Environmental 

Protection Agency, 2000a,b).

In the text, the Aggregate Nutrient Ecoregions are 

referred to as Ecoregion VI or IX; Level III Ecoregions are 

referred to as Ecoregion 55, 71, or 72. The nutrients are 

described as concentrations of nitrate, TKN, TN, and TP. In 

this report, periphyton CHLa, ash-free dry mass (AFDM), 

seston CHLa, and particulate organic carbon (POC) are considered measures of algal biomass.

This report provides data from the West Fork of the 

White River. The White River drains a substantial area of 

central Indiana (fig. 1). The White River is joined by the East 

Fork White River near Petersburg, Indiana, before flowing 

into the Wabash River. The White River is labeled as such on 

USGS maps above the confluence with the East Fork White 

River but commonly is referred to as the “West Fork” of the 

White River. The IDEM Probabilistic Watershed Program 

refers to the West Fork White River Basin. In this report, the 

“West Fork White River Basin” will be used. 

Description of the West Fork White River Basin

The West Fork White River Basin drains more than 

12,414 km2 (Hogatt, 1975) of central and southern Indiana 

and is joined by the East Fork White River at Petersburg, Ind., 

before flowing into the Wabash River. In water year 2001, 

the annual mean streamflow at the USGS streamflow-gaging 

station West Fork White River at Newberry, IN (03360500) 

(fig. 1), was 119.6 m3/s, which was below the annual mean 

long-term streamflow (1929-2001) of 137.7 m3/s at Newberry 

(Stewart and others, 2002). 

The climate in the West Fork White River Basin is characterized as humid continental with well-defined winter and 

summer seasons. The mean monthly temperature ranges from 

-2.78°C in winter to 23.9°C in summer (Schnoebelen and others, 1999). The mean annual precipitation ranges from about 

96.5 cm in the northern part of the basin to 111.8 cm in the 

south (Schnoebelen and others, 1999).

The dominant land use is agriculture (71 percent), primarily row crops such as corn and soybeans. Nineteen percent 

of the basin area is forested (Baker and Frey, 1997). Typical 

of many streams in the state, most streams in the West Fork 

White Rive Basin have low gradients and velocities. The largest urban areas are Indianapolis (population about 791,930), 

Muncie (population about 67,430), and Anderson (population 

about 59,730) (U.S. Census Bureau, 2000) (fig. 1).

Study Methods

This study used field and analytical methods from the 

IDEM and the USGS. The following sections describe the site 

selection and sampling strategies; field and laboratory methods 

used in collecting, processing, and analyzing algal-biomass, 

habitat, basin-characteristics, nutrients, and biological-community data; and data analysis used in this report.

Site Selection and Sampling Strategies

Sampling sites were selected randomly by the USEPA as 

part of the IDEM probabilistic Watershed Monitoring Program 

(WMP) (Indiana Department of Environmental Management, 

1999, 2001). Each selected sampling site (table 1) represents 

a specific stream order; therefore, statistically valid extrapolations can be made from the randomly sampled streams to the 

entire class of streams of that order in a particular basin. The 

IDEM WMP works on a 5-year rotating basin schedule, focusing on 1–2 selected basins each year, with a complete assessment of the state at the end of each 5-year cycle. In 2001, 

the focus was the West Fork White River. After the sampling 

sites were selected and prior to collection of field data, IDEM 

personnel completed a visual assessment of the potential sampling sites and determined the reach to be sampled at each site. 

At each of the USEPA randomly selected sites, the latitude 

and longitude was used as the middle point of the reach, with 

half of the reach upstream and half downstream of the middle 

point.

During periods of stable flow from July through September 2001, 34 sites in the West Fork White River Basin (fig. 1, 

table 1) were sampled two times for algal biomass and three 

times for nutrients. The samples were collected three times to 

measure seasonal changes in the algal biomass and nutrients. 

Round one of sampling was done in July and August (summer), and round two of sampling was done in September (fall). 

In this report, round one sampling will be referred to as spring 

or July and round two as fall or September. Water also was 

sampled for nutrients in May by IDEM personnel, however 

this data was not included in the analysis. Nutrient and algalbiomass samples were collected at roughly the same time of 

day. Habitat, fish, and invertebrate communities were sampled 

once by IDEM personnel in July and August. Sites that 

required a boat to collect nutrient and algal-biomass samples 

were not sampled for algal biomass in 2001.

Algal-Biomass, Habitat, Nutrient, and 

Biological-Community Data-Collection and 

Processing Methods 

Algal-biomass samples were collected and processed for 

periphyton and seston, as described in USGS protocols, with 

several modifications. The National Water-Quality Assessment 

(NAWQA) Program algal protocols for periphyton (Porter 

and others, 1993) are a reach-based sampling methodology 

in which five periphyton subsamples are collected from five 

different locations within the sampling reach. At each location, the stream depth, velocity, shading, and substrate were 
4 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

Base from U. S. Geological Survey digital data,

scales ranging from 1:24,000 to 1:250,000, 1999

Albers Equal Area projection

Standard parallels 29° 30' and 45° 30', central meridian -86°

North American Datum, 1927

0

10

10

20

20

30

30

40 MILES 

40 KILOMETERS 

0

86°

40°

39°

87°

 EXPLANATION

U.S. ENVIRONMENTAL PROTECTION AGENCY AGGREGATE NUTRIENT ECOREGION VI,

 LEVEL III ECOREGION 55

U.S. ENVIRONMENTAL PROTECTION AGENCY AGGREGATE NUTRIENT ECOREGION IX,

 LEVEL III ECOREGION 71

U.S. ENVIRONMENTAL PROTECTION AGENCY AGGREGATE NUTRIENT ECOREGION IX,

 LEVEL III ECOREGION 72

MAJOR STREAM

WEST FORK WHITE RIVER DRAINAGE BASIN BOUNDARY

WEST FORK WHITE RIVER SAMPLING SITES WITH SITE IDENTIFIER

U.S. GEOLOGICAL SURVEY STREAMFLOW-GAGING STATION

321

U

U

U

WHITE RIVER AT NEWBERRY, IN

WEST FORK WHITE RIVER BASIN

INDIANA ! ! !

! !

!

!

!

! !

!

!

! !

! ! !

!

!

! !

! ! !

! !

!

!

!

!

! !

!

!

301

341

313

321

305

337

303

344

306

340

320 330 336

346 304 338

322

343 348 314 332

318 324

316

342 327

331

302 335

347 339

319 311 323

U

River White

West

Fork

Petersburg

Muncie

Eel River

Fall

Creek

Anderson

Indianapolis

Figure 1. Location of the 34 algal-biomass sampling sites in West Fork White River Basin, Indiana, 2001.
Study Methods 

5

Table 1. Location and basin characteristics of the 34 algal-biomass sampling sites in the West Fork White River Basin, Indiana, July through September 2001.[IDEM, Indiana Department of Environmental Management; USGS, U.S. Geological Survey; ID, identification number; USEPA, U.S. Environmental Protection Agency; FT, feet; US, upstream; INDPLS, Indianapolis; CR, County Road; SR, State Route; DS, downstream; CK, Creek.; FK, Fork; DCH, Ditch; NR, near; AV, Avenue; ST, Street; N, North; S, South; E, East; W, West; IN, Indiana]

Short IDEM 

site number1 USGS station ID USGS station name

USEPA 

Aggregate 

Nutrient 

Ecoregion2

Level III 

Ecoregion3

Latitude

(degrees)

Longitude

(degrees)

301 384211087065501 EAGAN DITCH 1000 FT US CR 350N NR WASHINGTON, IN IX 72 38.70314 -87.11519

302 400620086050901 HINKLE CK 1500 FT US EAST 216TH ST AT DEMING, IN VI 55 40.10550 -86.08569303 391009086403001 RICHLAND CREEK 2200 FT US SR 43 AT WHITEHALL, IN IX 71 39.16925 -86.67497304 393410086085901 HONEY CR 2300 FT US SR 135 AT STONES CROSSING, IN VI 55 39.56947 -86.14986305 385847087123301 BREWER DCH 2000 FT DS CR 1450W NR PLEASANTVILLE, IN IX 72 38.97981 -87.20928306 392659086181801 SOUTH PRONG STOTTS CK 1200 FT US SR 44 AT COPE, IN VI 55 39.44967 -86.30492311 401606085532301 POLYWOG CK 3000 FT US CR 300S AT NEW LANCASTER, IN VI 55 40.26842 -85.88969313 384949087024201 KANE DITCH 1200 FT DS CR 700E NR EPSOM, IN IX 72 38.83017 -87.04497314 394234086112801 LICK CREEK 1200 FT DS SOUTH HARDING ST AT INDPLS VI 55 39.70931 -86.19117316 395256086242601 BEAMAN DITCH 3800 FT US CR 800N NR BROWNSBURG, IN VI 55 39.88219 -86.40722318 394734086133501 LITTLE EAGLE CREEK 2100 FT US WEST 16TH ST INDPLS VI 55 39.79292 -86.22642319 401451086110701 KIGIN DITCH 300 FT US CR 900W NR EKIN, IN VI 55 40.24744 -86.18542320 393046086573501 BIG WALNUT CK 3700 FT US 1-70 NR PLEASANT GARDENS IX 72 39.51281 -86.95969321 385116086565701 UNNAMED CREEK 3500 FT DS CR 1100E NR FARLEN, IN IX 72 38.85442 -86.94911322 393855086245601 W FK WHITE LICK CK 1500 FT US I-70 NR PLAINFIELD VI 55 39.64856 -86.41567323 401449085311801 JAKES CREEK 600 FT DS CR 700W AT BETHEL, IN VI 55 40.24683 -85.52169324 395003086410401 BIG WALNUT CREEK 1600 FT US CR 900E NR BARNARD, IN VI 55 39.83422 -86.68439327 400046085370901 FALL CREEK 1300 FT DS CR 300E NR EMPORIA, IN VI 55 40.01286 -85.61917330 393022086313401 LAMBS CREEK 1600 FT DS BEREAN RD NR WILBUR,IN IX 71 39.50614 -86.52622
6 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001 Table 1. Location and basin characteristics of the 34 algal-biomass sampling sites in the West Fork White River Basin, Indiana, July through September 2001.—Continued [IDEM, Indiana Department of Environmental Management; USGS, U.S. Geological Survey; ID, identification number; USEPA, U.S. Environmental Protection Agency; FT, feet; US, upstream; INDPLS, Indianapolis; CR, County Road; SR, State Route; DS, downstream; CK, Creek.; FK, Fork; DCH, Ditch; NR, near; AV, Avenue; ST, Street; N, North; S, South; E, East; W, West; IN, Indiana] Short IDEM site number1 USGS station ID USGS station name USEPA Aggregate Nutrient Ecoregion2 Level III Ecoregion3 Latitude (degrees) Longitude (degrees) 340 392755086444401 MILL CREEK 3800 FT US CR 1150N AT WALLACE JUNCTION IX 71 39.46536 -86.74544 341 384333087082001 N FK PRARIE CK 3000 FT US CR 100E NR WASHINGTON, IN IX 72 38.72586 -87.13886 342 395935086163801 EAGLE CREEK 2600 FT US WEST 146TH ST AT ZIONSVILLE VI 55 39.99303 -86.27725 343 394214086065501 LICK CK 600 FT DS OF CARSON AV AT BEECH GROVE, IN VI 55 39.70392 -86.11519 344 392116087052501 TURKEY CREEK 500 FT US CR 665 NR SALINE CITY, IN IX 72 39.35447 -87.09036 346 393402086384301 MUD CREEK 5300 FT DS CR 1100W AT LITTLE POINT, IN VI 55 39.56731 -86.64531 347 401219085344901 KILLBUCK CREEK 500 FT DS CR 800N NR GILMAN, IN VI 55 40.20533 -85.58031 348 394307086474301 BLEDSOE BRANCH 500 FT US CR 400N NR FILLMORE, IN VI 55 39.71867 -86.79542

1The full IDEM site number has a prefix of INRB, for example INRB01-301.2U.S. Environmental Protection Agency, 2000a,b.3U.S. Environmental Protection Agency, 1997b.
Study Methods 7

recorded. The subsamples were composited and marked as a 

single sample. At each site, periphyton samples were collected 

using the same substrate type—epilithic (rocks), epidendric 

(sticks), or epipsammic (sand)—during the sampling period. 

One modification to this study from the NAWQA protocols 

was that 10 periphyton subsamples were collected from the 

same substrate as close to the center of the reach as possible. 

Then five subsamples were selected that best represented the 

average algal cover at the sampled reach and these subsamples 

were composited into a single sample (Charles and others, 

2000).

Seston samples were collected, following NAWQA 

surface-water sample protocols (Shelton, 1994), along the 

IDEM-specified transect with a 3-L bottle and a 0.476-cm 

nozzle; either a grab sample or a multiple vertical method was 

used. After the seston sample was collected, it was processed, 

following NAWQA algal protocols (Porter and others, 1993). 

Algal-biomass samples were collected, homogenized, and 

filtered onto glass-fiber filters in the field by USGS personnel. 

All filters collected by the USGS were placed on dry ice and 

transported to the USGS Indiana Water Science Center laboratory for analysis. The CHLa and AFDM filters were analyzed 

at the USGS Indiana Water Science Center laboratory; all the 

POC filters were analyzed at the USGS National Water Quality Laboratory (NWQL) in Lakewood, Colorado. 

Concentrations of CHLa were determined, following 

USEPA method 445, with a Turner Designs TD-700 fluorometer outfitted for CHLa analysis (Arar and Collins, 1997). 

There were two exceptions to method 445; filters were ground 

in Nalgene centrifuge tubes instead of glass to counter the 

problem of tube breakage, and samples were centrifuged at 

1,500 revolutions per minute (approximately 320 g) for 

15 minutes. At the modified centrifuge rate, the filter residue and acetone solution separated well. If samples did not 

separate well, they were placed in the centrifuge a second time 

or care was taken not to decant the solute. For consistency, all 

samples were allowed to steep for 2.5 hours. Concentrations of 

AFDM were determined, following USGS method B-3520-85 

(Britton and Greeson, 1988) with two exceptions: the samples 

were filtered in the field, and the filters were not baked and 

weighed in the crucibles before use. 

Quality-assurance methods for algal biomass samples 

included triplicate filters from the same sample to measure 

variability and a blank filter collected at each sampling reach 

to measure bias. Additionally, a fifth filter was collected at 

each site and 15 percent of these fifth CHLa filters were analyzed at the NWQL to measure laboratory variability.

Habitat assessments were collected one time, July 

through August 2001, at each site by IDEM personnel following standard IDEM methods (Indiana Department of Environmental Management, 1992). Habitat assessments were made 

at the same time fish communities were sampled. Habitat 

assessments include in-stream and riparian measurements that 

are incorporated into the Qualitative Habitat Evaluation Index 

(QHEI). A list of these habitat metrics are listed in appendix 1 

(Dufour, 2002). 

Nutrient samples (ammonia, nitrate, TKN, TN, and TP) 

were collected by IDEM personnel following approved IDEM 

methods (Beckman, 2000). Nutrient quality-assurance methods followed approved IDEM methods (Bowren and Ghiasuddin, 1999). The nutrient samples were preserved by IDEM 

personnel, placed on wet ice, and taken to an independent 

laboratory (Test America, Indianapolis) for analysis. 

Biological-community (fish and invertebrates) samples 

were collected one time, July through September 2001, at each 

site by IDEM personnel following standard IDEM methods 

(Indiana Department of Environmental Management, 1992; 

Barbour and others, 1999). IDEM personnel calculated the 

biological-community attributes and metric scores for this 

study. Attributes are the raw data and metric scores are rankings of the data from poor (a score of one), fair to good (a 

score of three), and excellent (a score of 5). The metric scores 

are ranked using a large data set that includes unimpaired 

reference sites to impaired sites. Each attribute has a corresponding metric score (Dufour, 2002). A list of the fish and 

invertebrate attributes and metrics are listed in appendix 1.

Data sets for sampling dates, laboratory-analysis dates, 

and algal-biomass (periphyton and seston) are available at:

http://in.water.usgs.gov/NAWQAWHMI/neet.php

Data Analysis

In large environmental datasets, natural variability often 

masks the relations among variables. An objective of this 

report was to develop a preliminary understanding of how 

algal biomass relates to biological community and environmental variables in the West Fork White River Basin in 2001. 

In this report, the environmental variables included nutrients, 

habitat, and basin characteristics. Two approaches were used 

for the preliminary analysis of the data sets. The first approach 

included ordination and regression analyses of the algal biomass, nutrient, and environmental data. The second approach 

compared the CHLa and nutrient values collected by IDEM 

and USGS personnel to USEPA published values. These 

approaches provided an exploratory analysis to identify which 

biological and environmental variables were significantly 

related to algal biomass. These approaches also were used as 

a data censoring tool and allowed researchers to determine the 

relations of interest to use as a starting point in future studies.

The ordination approach consisted of determining yearly 

site scores for the periphyton and seston data using PCA. The 

ordination approach consisted of determining site scores for 

the periphyton and seston data using PCA. In each PCA two 

measures of algal biomass for periphyton (CHLa and AFDM) 

and seston (CHLa and POC) were used. The site scores are 

considered yearly because all of the seasonal algal biomass 

data are included in the PCA site score determination. The 

regression approach related the periphyton and seston PCA 

site scores from the first axis to five basin characteristics, nine 

habitat, 12 nutrient variables, and 43 fish and 21 invertebrate 

attribute and metric scores. All data were normalized to a 
8 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

z-score prior to use in the data analyses, allowing for comparison of variables that were recorded in different units.

Basin-Characteristics Data

The basin characteristics used in this analysis were drainage area and land use (percentage of agriculture, forest, other, 

and urban) and these were determined by the USGS for this 

study. Drainage area was derived from the basin boundaries. 

Basin boundaries for each site were generated following the 

method outlined by Ries, III, and others (2004). This method 

combines the National Elevation Dataset, Digital Elevation 

Model data, and the National Hydrography Dataset, which is a 

comprehensive set of digital surface-water features. The basin 

boundaries were used to extract land-use information from 

the National Land Cover Dataset (NLCD) (U.S. Geological 

Survey, 2000). This conversion allowed the land-use data to be 

compared among and between basins. Each sampling site was 

assessed to determine in which Aggregate Nutrient Ecoregion 

(U.S. Environmental Protection Agency, 2000a,b) and Level 

III Ecoregion (U.S. Environmental Protection Agency, 1997b) 

it was located.

Nutrient Data

The nutrients used in this analysis were dissolved ammonia as N, dissolved nitrate plus nitrite as N, total Kjeldahl 

nitrogen as N, total nitrogen as N, and total phosphorus as 

P. Because concentrations of nitrate typically are two orders 

of magnitude greater than nitrite and because nitrite usually does not exceed 0.5 mg/L in surface water (National 

Research Council, 1978), concentrations of nitrite plus 

nitrate are referred to as nitrate in this report. Concentrations 

of total nitrogen were calculated as the sum of nitrate and 

TKN. Almost all of the ammonia data were censored below 

the reporting levels and were not included in the analysis. 

For nutrient analyses, the scope of this report is narrowed to 

nitrate, TKN, TN, and TP. Nutrient data was analyzed separately for the summer (July and August) and the fall (September) samples; the seasonal nutrient and the seasonal algal-biomass data were then compared to the PC1 sites scores using 

Spearman’s rho to determine the most significant seasonal 

relations. Because algal-biomass samples were not collected in 

spring (May), comparisons between spring nutrient and spring 

algal-biomass concentrations could not be done.

Principal Components Analysis

Principal Components Analysis, an ordination technique, was used to calculate individual yearly algal-biomass 

site scores for the periphyton and seston samples. PCA site 

scores (Gauch, 1982; Jongman and others, 1995; McCune 

and Grace, 2002) are theoretical variables that minimize the 

total residual sum of squares after fitting straight lines to the 

algal-biomass data. Mean CHLa (periphyton and seston) and 

AFDM values were calculated from the three filters for each 

sample. Mean algal-biomass (periphyton and seston) and other 

data were normalized prior to running the ordination analysis. 

To calculate the yearly periphyton PCA site scores, the mean 

periphyton CHLa and mean AFDM data from the July and the 

September sampling were used; for the yearly seston PCA site 

scores the mean seston CHLa and POC data from the July and 

the September sampling were used.

In this report, a positive site score indicates an increase in 

algal-biomass along the axis and a negative site score indicates 

a decrease in algal-biomass along the axis. Only the principal 

components (PC) site scores from the first axis (PC1) are presented in this preliminary analysis, because the PC1 axis best 

explains the algal-biomass data (McCune and Grace, 2002). 

In theory, the PC1 site scores should be related to the variables that were used in the calculations, and the variable with 

the highest loading accounts for the majority of the variation, 

which should also have the highest correlation coefficient. 

As a validation step, the yearly periphyton and yearly seston 

PC1 site scores were related to the algal biomass-values, using 

Spearman’s rho. The purpose of this preliminary analysis was 

to investigate all potential relations and identify those relations that were the strongest and warrant further investigation. In this report, for a relation to be considered statistically 

significant using PCA, the Spearman’s rho statistic (rS) was 

required to be greater than the absolute value of 0.45 and have 

at least a 95 percent significance level based on the sample 

size. Although an rS of 0.45 is considered significant, it has a 

possibility of introducing a Type I error.

Several procedures—such as the Bonferroni correction—

are available for adjusting the significance level when performing a large number (or “family”) of tests simultaneously 

(Van Sickle, 2003). This adjustment reduces the chances of a 

Type I error (the relation is declared present when the relation is not present) at a specific alpha level. Although useful 

in reducing Type I error, this technique increases the chance 

of producing a Type II error (no relation declared when a 

relation is present). In this study, the goal was to investigate 

all potential relations and identify which relations were the 

strongest. Because this was a preliminary analysis and there 

were a limited number of significant relations, no corrections 

were applied. 

The yearly PC1 site scores spatially represent the (periphyton and seston) algal-biomass and were related, using 

Primer V.6.1.5 (Primer-E Ltd, 2006), to the habitat, basincharacteristics (drainage area and land use), seasonal nutrient 

(summer (July) and fall (September) nitrate, TKN, TN, and 

TP), seasonal algal biomass (summer (July) and fall (September) CHLa, AFDM, and POC), and biological-community 

(fish and invertebrates) attributes and metric score data collected in 2001. Spearman’s rank order (rho) correlations are 

the preferred method when determining relations among environmental data because (1) the initial sample size was greater 

than 30 for most variables and (2) environmental data typically 

are not normally distributed. Although the data from this study 

were normalized prior to analysis, all variables were not nor-
Relations of the Principal Components Analysis Site Scores 9

mally distributed, requiring a non-parametric statistic. PC site 

scores were related in a correlation matrix to determine the 

strongest relations. The variables with the strongest relations 

could help in the development of nutrient criteria.

Comparison With U.S. Environmental Protection 

Agency Data 

The USEPA proposed criteria in 2000 for nitrate, TKN, 

TN, TP, CHLa (periphyton and seston), and turbidity at the 

25th-percentile value of all data for each parameter for each 

Aggregate Nutrient and Level III Ecoregion. Consequently, the 

second analytical approach was to determine how the data collected by IDEM and USGS for CHLa and nutrients compared 

to USEPA published values (U.S. Environmental Protection 

Agency, 2000a,b). For the USEPA method, the median value 

for each parameter for each stream was calculated. Then, percentiles were determined for each of the four seasons in each 

ecoregion and the 25th-percentile of the combined four seasons 

was used as the proposed criteria. In this report, median 

nutrient (nitrate, TKN, TN, and TP) and CHLa values were 

calculated for all streams sampled within the same Aggregate 

Nutrient and Level III Ecoregions. However, seasonal statistics 

were not calculated because IDEM and USGS did not collect 

winter samples or spring samples—USEPA considers May 

as part of spring. In this report, the median values for all the 

streams within a specific ecoregion were used to calculate 

descriptive statistics (ranges—minimum and maximum—and 

percentiles—10th, 25th, 50th, 75th, and 90th). For CHLa (periphyton and seston), a mean of the three filters collected at 

each site was calculated and then a median of the means for 

all streams within each ecoregion was used to calculate the 

descriptive statistics. The descriptive statistics then were compared to published USEPA values for Ecoregions VI, IX, 55, 

and 72 (U.S. Environmental Protection Agency, 2000a,b).

Relations of the Principal Components 

Analysis Site Scores to Algal-Biomass, 

Habitat, Basin-Characteristics, 

Nutrient, and Biological-Community 

Data

PCA was used to calculate PC1 site scores from the 

algal-biomass (periphyton and seston) data for each site (all 

seasons). The periphyton PC1 site score was constrained by 

AFDM (July); the PC2 was constrained by CHLa (September). The combination of PC1 (60.6 percent) and PC2 (25.6 

percent) site scores accounted for 86.2 percent of the total 

variation. The seston PC1 site score was constrained by the 

POC (September); the PC2 was constrained by the CHLa 

(September). The combination of PC1 (57.4 percent) and PC2 

(23.6 percent) accounted for 81.0 percent of the variation. 

Because the PC1 site score accounted for a large amount of 

the total variation in both of the algal-biomass data sets, only 

PC1 (periphyton and seston) site scores were compared to the 

seasonal algal-biomass, habitat, basin-characteristics (drainage 

area and land use), seasonal nutrient, and biological-community (fish and invertebrates) attributes and metric score data.

The periphyton PC1 site score (table 2) was negatively 

related to two algal-biomass variables: mean periphyton CHLa 

(July) and mean AFDM (July and September). Although 

this result does not offer inferences about the relations of the 

periphyton PC1 site score to the environmental or biologicalcommunity (fish and invertebrate attributes and metric scores) 

data, these relations demonstrate that the periphyton PC1 

site score represents an algal-biomass gradient that is largely 

defined by CHLa (July) and AFDM (July and September). 

The periphyton PC1 site score, which is most influenced 

by July CHLa, was negatively related to one of nine habitat 

parameters (percent closed canopy) that were examined. This 

suggests that as the amount of closed canopy cover decreases 

the periphyton algal biomass increases. It is expected that as 

canopy cover opens, more light would reach the stream and 

increase algal-biomass growth (Vannote and others, 1980). 

The periphyton PC1 site score was positively related to one 

fish-community attribute (appendix 1) of 21 examined (percent tolerant), one invertebrate-community attribute of ten 

examined (EPT index), and one invertebrate-community metric score of ten examined (EPT index metric score). The shift 

to more tolerant fish species as algal biomass increases suggests a decrease from fair to poor water quality (Simon, 1991). 

One mechanism that could explain this shift to tolerant species 

is the increase in certain tolerant fish species (green sunfish, 

white sucker) capable of handling large diurnal swings in 

dissolved oxygen related to high algal-biomass levels. Often 

the higher the EPT index the better the water quality (Voelker, 

2003). However, many EPT taxa are filter feeders (Isonychia

and Hydropsyche) which might benefit from increased algalbiomass concentrations. The periphyton PC1 was not related 

to the basin characteristics or nutrients. 

The seston PC1 site score (table 3), which is most 

influenced by September POC, was negatively related to four 

algal-biomass variables: mean seston CHLa (July and September) and POC (July and September). Although these relations 

do not offer inferences to the relations of the seston PC1 site 

score to the environmental or biological-community (fish and 

invertebrate attributes and metric scores) data, these relations 

demonstrate that the seston PC1 site score represents an algalbiomass gradient that is largely defined by CHLa (July and 

September) and POC (July and September).

The seston PC1 site score was also negatively related to 

two nutrient variables: TKN (July) and TP (July). The only 

significant relations with nutrients were in July and suggest 

that as algal-biomass increases in July, it reduces the nutrient 

concentrations through algal uptake. It also suggests that the 

best time to sample seston would be during the summer and 

fall to find significant relations between nutrients and algal 
10 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

Table 2. Significant Spearman’s rho relations of the yearly periphyton Principal Components Analysis axis 1 site scores (PC1) to algal 

biomass, habitat, basin characteristics, and nutrients and fish- and invertebrate-community attributes and metric scores, 2001.

[rs, Spearman’s rho statistic (probability <0.05); n, number of samples; ns, no statistically significant relations EPT, Ephemeroptera, Plecoptera, Trichoptera]

Category Parameter and attribute/metric r

s

Parameter

Periphytonalgal biomass (n=30) Mean ash-free dry mass, July -0.8051

Mean ash-free dry mass, September - .5172

Mean periphyton chlorophyll a, July - .8857

Habitat (n=30) Percent open canopy - .4969

Basin characteristics (n=30) ns ns

Nutrients (n=30) ns ns

Attribute/metric

Fish (n=30) Percent tolerant .4830

Invertebrates (n=16) EPT index .6439

EPT index metric score .6356

biomass. One possible reason for significant relations in summer and fall may be that nutrient concentrations are uniformly 

high during the spring (compared to the summer and fall) 

because of application of fertilizer and increased runoff from 

more-frequent and larger precipitation events. Also, higher 

algal growth tends to occur during periods of stable flow and 

warmer weather typically associated with fall. Because algalbiomass samples were not collected in the spring, it was not 

possible to determine from this study if spring is the time to 

see relations between the algal-biomass and nutrients. However, in similar IDEM/USGS studies conducted in 2002 in the 

East Fork White River and Whitewater River Basins (Caskey 

and others, 2007) and in 2003 in the Upper Wabash River 

Basin (Leer and others, 2007), the most numerous and most 

significant relations between algal-biomass and nutrients were 

in the fall and summer.

The seston PC1 site score was not significantly related to 

the habitat and basin-characteristics variables. The seston PC1 

site score was negatively related to one fish-community attribute of 21 examined, large-river percent, and one invertebratecommunity attribute of ten examined, EPT-to-total ratio. The 

significant relation suggests that as algal-biomass increases, 

the percent of large river fish decreases is probably more a 

function of the lack of large river sites sampled in the 2001 

study than an ecological reason; no boat sites were sampled in 

2001. The decrease in the EPT to total ratio as algal biomass 

increases suggests a decrease in water quality. 

The only significant relation in Ohio streams that Miltner 

and Rankin (1998) found between nutrients and biological communities was with the fish community. No relations 

between nutrients and the invertebrate community were found. 

In this 2001 study, both fish and invertebrate community variables showed statistically significant relations to algal-biomass 

and suggest that both biological communities may be a useful 

measure of nutrient enrichment in streams. Significant relations between algal-biomass and fish- and invertebrate-community data were found in the data analysis for similar studies 

in the East Fork White River and Whitewater River Basins in 

2002 (Caskey and others, 2007) and the Upper Wabash River 

Basin in 2003 (Leer and others, 2007). Additionally, a change 

in fish-community composition was suggested in the 2002 and 

2003 studies. In the 2002 study, as periphyton algal biomass 

increased, fish-community composition shifted from one dominated by carnivores and other niche-specific specialists to a 

community dominated by generalist-feeding and pioneer species. In the 2003 study, as periphyton algal biomass increased, 

fish-community composition shifted from one dominated by 

insectivores to a community dominated by tolerant species. 

The low number and weak relations of the periphyton and 

seston PC1 site scores to the invertebrate community (attributes and metric scores) may be the result of three possible 

factors: (1) sample size, (2) sample method, and (3) taxonomic 

resolution of invertebrate data. In multivariate studies, sample 

size has been shown to affect the inferences that can be drawn 

from a data set; this may be why no relations were noted 

between the PC1 (periphyton and seston) and the invertebratecommunity attributes and metric scores. In this study, invertebrates were collected only at sites with riffles; only 16 or 

19 sites had algal-biomass and invertebrate community data; 

compared to 30 and 33 sites for the algal-biomass and fishcommunity data. Another possible reason for the lack of invertebrate-community attributes and metric score relations could 
Drainage-Area and Land-Use Analysis 11

be related to the collection methods. The invertebrate-community samples were collected from a specific habitat type (riffle) 

within the sampling reach; this targeted-habitat approach 

represents only the habitat sampled. If a multihabitat approach 

had been used for the collection of the invertebrate communities it may have revealed a community more representative 

of the entire sampling reach; this multihabitat approach may 

have increased the number of significant relations between the 

PC1 sites scores and the invertebrate-community attributes and 

metrics. Finally, the lack of invertebrate-community attribute/

metric score relations also could be the result of invertebrateidentification resolution. IDEM identifies invertebrates to 

family level; therefore, it is possible that if identification were 

to a lower taxonomic level, a statistically significant relation 

between PC1 (periphyton and seston) and invertebrate-community attributes and metric scores could be documented.

Drainage-Area and Land-Use Analysis 

Basin characteristics such as drainage area and land use 

can affect the relations between nutrients, algal biomass, and 

biological-community data. To understand how the choice of 

sampling sites might have affected the results, an analysis of 

the drainage area and land use was done. The drainage area 

and land-use values in this section were determined by the 

USGS for this study.

The random site selection in 2001 in the West Fork White 

River Basin was skewed to small streams. Of the 34 sites sampled in the West Fork White Basin, 61.8 percent were headwater streams (less than 50 km2

); all of the sites were wadeable, 

small streams less than 854 km2 (fig. 2A). In the West Fork 

White River Basin, drainage-basin size ranged from 1.5 km2 to 

853.8 km2 (table 4). Because of the small basin size for many 

of the sites, the lack of relations among the periphyton PC1 

and the habitat, basin-characteristics, nutrient, and biologicalcommunity data was not expected. The River Continuum 

Concept (Vannote and others, 1980) suggests that periphyton 

would dominate primary production in smaller streams, with 

more suitable substrate (rock, sticks, sand), shallower water, 

and less turbidity than in larger streams. As streams get larger, 

deeper, and have less shading, seston would dominate primary 

production. It follows that the significant relations would 

be with the periphyton instead of the seston algal biomass. 

Because larger (boat) sites were not sampled for algal biomass 

in 2001, it is possible that there was not enough of a gradient 

to observe significant relations with basin size.

Although there were no large streams sampled in the 

West Fork White River Basin, there was still a gradient from 

headwater to medium-sized (wadeable) streams (fig. 2A). The 

large range of basin drainage area that was sampled could 

account for, or influence, the significant relations documented 

by the PC1 (periphyton and seston) and the environmental 

and biological-community data. Previous studies suggest that 

drainage-basin size (stream order) could mask relations of 

Table 3. Significant Spearman’s rho relations of the yearly seston Principal Components Analysis axis 1 site scores (PC1) to algal 

biomass, habitat, basin characteristics, and nutrients and fish- and invertebrate-community attributes and metric scores, 2001.

[rs, Spearman’s rho statistic (probability <0.05); n, number of samples; ns, no statistically significant relations; N, nitrogen; P, phosphorus; EPT, Ephemeroptera, 

Plecoptera, Trichoptera

Category Parameter and attribute/metric r

s

Parameter

Seston algal biomass (n=33) Particulate organic carbon, July -0.8332

Particulate organic carbon, September - .8325

Mean seston chlorophyll a, July - .7390

Mean seston chlorophyll a, September - .5842

Habitat (n=33) ns ns

Basin characteristics (n=33) ns ns

Nutrients (n=33) Total Kjeldahl nitrogen-N, July - .6518

Total phosphorus-P, July - .5049

Attribute/metric

Fish (n=33) Large-river percent - .5833

Invertebrates (n=19) EPT to total ratio - .4915
12 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

environmental variables to biological communities. Stream 

size was significant in explaining relations between algalcommunity assemblages (Carpenter and Waite, 2000) and 

fish-community assemblages (Caskey, 2003) and environmental variables. Different fish and algal communities were found 

in small streams compared to large streams. Additionally, 

stronger relations were found between nutrients and fish- and 

invertebrate-community attributes and metric scores when 

data was analyzed by basin size (Frey and Caskey, 2007). 

Miltner and Rankin (1998) found the only significant relations between nutrients (TP and total inorganic nitrogen) and 

biological communities (fish) were in headwater streams. For 

this report, to keep the sample size large, analysis was done on 

all sites combined.

The dominant mean land use of the sites sampled in the 

West Fork White River Basin was agriculture (81.0 percent), 

followed by forest (10.5 percent) and urban (7.5 percent) 

(table 4). Of the streams that were sampled, 71 percent of the 

sites had at least 76 percent agricultural land use in the basin 

(fig. 2B). Agricultural land use of the West Fork White River 

Basin sites ranged from 39.7 to 98.7 percent (table 4). In a 

study of Midwest agriculturally dominated landscapes, Wang 

and others (1997) noted when land use within a drainage basin 

is less than 50 percent agriculture, biological-community 

relations are complex and difficult to identify. As the percentage of agricultural land use increases to more than 50 percent, 

however, a significant negative relation can be observed with 

fish Index of Biological Integrity (IBI) scores. Because most 

basins in this study had more than 76 percent agricultural land 

use, an agricultural land-use gradient was not found. This lack 

of an agricultural land-use gradient potentially could mask 

relations among the PC1 site scores (periphyton and seston) 

and the environmental variables and biological-community 

(fish and invertebrates) attributes and metric scores. 

About 88 percent of the sites in the West Fork White 

River Basin had basins that consisted of less than 25 percent 

forest land use (fig. 2C). The forested land use of the West 

Fork White River Basin sites ranged from 0.2 to 54.7 percent 

(table 4). Studies have shown that forested landscapes are less 

likely to have elevated nutrients. This is in part because an 

established riparian zone acts as a buffer and filters surfacewater runoff (Jordan and others, 1993).

Almost all of the sites in the West Fork White River 

Basin had basins that consisted of less than 25 percent urban 

land use (fig. 2D). The urban land use of the West Fork 

White River Basin sites ranged from 0 to 55.0 percent; about 

92 percent of the sites had less than 10 percent urban land use 

(table 4). Studies from across the United States have shown 

that agricultural and urban landscapes can have elevated levels 

of nutrients (Mueller and Helsel, 1996). If nutrient concentrations were elevated at all the sites, the lack of a nutrient 

gradient could potentially mask relations among the PC1 

(periphyton and seston) and the environmental variables and 

biological-community (fish and invertebrates) attributes and 

metric scores.

Figure 2. Graphs showing the percentage of drainage area and 

agricultural, forest, and urban land use in the West Fork White 

River Basin, Indiana, 2001.

0

20

40

60

80

100

0-25 26-50 51-75 76-100

PERCENTAGE OF BASIN, AGRICULTURE

PERCENTAGE OF SITES

WITHIN BASIN

B.

0

20

40

60

80

100

0-50 51-1000 > 1,000

DRAINAGE AREA (SQUARE KILOMETERS)

PERCENTAGE OF SITES WITHIN BASIN

Headwater

Wadeable Boat

0

20

40

60

80

100

0-25 26-50 51-75 76-100

PERCENTAGE OF BASIN, FOREST 

PERCENTAGE OF SITES

WITHIN BASIN

C.

20

40

60

80

100

0-25 26-50 51-75 76-100

PERCENTAGE OF BASIN, URBAN

PERCENTAGE OF SITES

WITHIN BASIN

D.

A.

0
Drainage-Area and Land-Use Analysis 13

Table 4. Basin characteristics of the 34 algal-biomass sampling sites in the West Fork White River Basin, Indiana, July through September 2001.[IDEM, Indiana Department of Environmental Management; USGS, U.S. Geological Survey; ID, identification number; USEPA, U.S. Environmental Protection Agency; FT, feet; US, upstream; INDPLS, Indianapolis; CR, County Road; SR, State Route; DS, downstream; CK, Creek.; FK, Fork; DCH, Ditch; NR, near; AV, Avenue; ST, Street; N, North; S, South; E, East; W, West; IN, Indiana]

Short IDEM 

site number1 USGS station name Drainage area (km2) Land use (percentage)2 Ag Forest Urban Other

301 EAGAN DITCH 1000 FT US CR 350N NR WASHINGTON, IN 21.7 95.9 2.9 1.1 0.0302 HINKLE CK 1500 FT US EAST 216TH ST AT DEMING, IN 46.9 96.7 2.0 .3 1.0303 RICHLAND CREEK 2200 FT US SR 43 AT WHITEHALL,IN 17.9 49.8 45.8 .6 3.8304 HONEY CR 2300 FT US SR 135 AT STONES CROSSING,IN 7.8 90.3 1.1 8.6 .0305 BREWER DCH 2000 FT DS CR 1450W NR PLEASANTVILLE,IN 32.1 49.8 37.7 .4 12.1306 SOUTH PRONG 1200 FT US SR 44 AT COPE,IN 83.7 77.9 21.0 .7 .4311 POLYWOG CK 3000 FT US CR 300S AT NEW LANCASTER, IN 38.0 98.0 .9 .5 .6313 KANE DITCH 1200 FT DS CR 700E NR EPSOM,IN 23.4 90.0 4.8 5.1 .1314 LICK CREEK 1200 FT DS SOUTH HARDING ST AT INDPLS 58.5 39.7 5.0 55.0 .4316 BEAMAN DITCH 3800 FT US CR 800N NR BROWNSBURG, IN 6.9 98.7 .2 1.2 .0318 LITTLE EAGLE CREEK 2100 FT US WEST 16TH ST INDPLS 49.6 44.8 5.3 49.4 .5319 KIGIN DITCH 300 FT US CR 900W NR EKIN, IN 4.1 98.0 1.2 0 .9320 BIG WALNUT CK 3700 FT US 1-70 NR PLEASANT GARDENS 853.8 81.7 16.4 1.2 .8321 UNNAMED CREEK 3500 FT DS CR 1100E NR FARLEN, IN 1.5 60.6 38.8 0 .6322 W FK WHITE LICK CK 1500 FT US I-70 NR PLAINFIELD 160.5 89.0 7.9 2.6 .6323 JAKES CREEK 600 FT DS CR 700W AT BETHEL, IN 46.1 73.9 5.3 19.8 1.0324 BIG WALNUT CREEK 1600 FT US CR 900E NR BARNARD, IN 308.8 96.7 2.2 .8 .3327 FALL CREEK 1300 FT DS CR 300E NR EMPORIA, IN 118.3 92.3 5.9 1.1 .7330 LAMBS CREEK 1600 FT DS BEREAN RD NR WILBUR,IN 30.2 43.9 54.7 .4 1.1331 CICERO CREEK 5000 FT US SR 38 AT NOBLESVILLE, IN 558.0 94.2 1.4 1.9 2.5332 PLUM CREEK 1800 FT US CR 800N AT NEW MAYSVILLE, IN 4.9 97.1 2.9 0 0335 WHITE RIVER 2800 FT DS CR 200S NR WINCHESTER, IN 26.7 97.4 2.3 0 .3336 BILLY CREEK 400 FT DS CR 125S NR HARMONY,IN 19.3 74.9 13.3 10.1 1.7337 SLOAN DITCH 4800 FT DS SR 67 NR DIXON,IN 9.4 86.9 1.8 11.3 .1
14 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001 Table 4. Basin characteristics of the 34 algal-biomass sampling sites in the West Fork White River Basin, Indiana, July through September 2001.—Continued [IDEM, Indiana Department of Environmental Management; USGS, U.S. Geological Survey; ID, identification number; USEPA, U.S. Environmental Protection Agency; FT, feet; US, upstream; INDPLS, Indianapolis; CR, County Road; SR, State Route; DS, downstream; CK, Creek.; FK, Fork; DCH, Ditch; NR, near; AV, Avenue; ST, Street; N, North; S, South; E, East; W, West; IN, Indiana] Short IDEM site number1 USGS station name Drainage area (km2

)

Land use (percentage)2

Ag Forest Urban Other

338 E FK WHITE LICK CK 1400FT US OLD 67 MOORESVILLE 125.7 79.7 5.3 14.5 .5339 LAMBERSON DITCH 1300 FT US CR 700N NR AROMA, IN 14.5 96.6 .9 1.6 .9340 MILL CREEK 3800 FT US CR 1150N AT WALLACE JUNCTION 563.1 91.5 7.5 0.7 0.3341 N FK PRARIE CK 3000 FT US CR 100E NR WASHINGTON,IN 159.7 91.2 7.5 .1 1.2342 EAGLE CREEK 2600 FT US WEST 146TH ST AT ZIONSVILLE 154.8 95.8 2.6 .7 .8343 LICK CK 600 FT DS OF CARSON AV AT BEECH GROVE,IN 46.6 43.3 5.4 50.9 .4344 TURKEY CREEK 500 FT US CR 665 NR SALINE CITY, IN 13.7 84.2 13.4 .1 2.3346 MUD CREEK 5300 FT DS CR 1100W AT LITTLE POINT,IN 93.4 95.4 3.3 1.3 .1347 KILLBUCK CREEK 500 FT DS CR 800N NR GILMAN, IN 158.8 85.8 5.1 8.1 1.0348 BLEDSOE BRANCH 500 FT US CR 400N NR FILLMORE, IN 12.6 71.5 24.5 4.0 0

Minimum 1.5 39.7 .2 0 0

Mean 113.8 81.0 10.5 7.5 1.1

Median 42.0 89.5 5.2 1.1 .6

Maximum 853.8 98.7 54.7 55.0 12.1

Standard deviation 188.9 19.1 13.9 14.8 2.1

1The full IDEM site number has a prefix of INRB, for example INRB01-301.2Land-use percentages were determined by the U.S. Geological Survey using the National Land Cover Dataset (U.S. Geological Survey, 2000).
Drainage-Area and Land-Use Analysis 15

Comparison of the Data to Ecoregion 

Nutrient Criteria

The values for nutrients (nitrate, TKN, TN, and TP) and 

CHLa (periphyton and seston) were compared to published 

USEPA values for the respective ecoregions. A comparison 

of the values from the IDEM/USGS and USEPA data sets 

was done to (1) determine whether USEPA data, which were 

used to set the nutrient water-quality criteria, and the IDEM/

USGS data had similar ranges of values; and (2) determine if 

the IDEM/USGS streams would exceed the proposed USEPA 

25th-percentile nutrient water-quality criteria for the ecoregions. Of the 34 sites sampled, 22 sites on 21 streams were in 

Ecoregion VI; 12 sites on 12 streams were in Ecoregion IX 

(fig. 1, table 1). All of the 22 streams sampled in Ecoregion 

VI were also in Ecoregion 55. Nine of the 12 streams sampled 

in Ecoregion IX were in Ecoregion 72; the 3 remaining sites 

sampled in Ecoregion IX were in Ecoregion 71. Because only 

three streams were in Ecoregion 71, no comparison was made 

with published USEPA values. In general, the range of data for 

most variables was similar between the USEPA and IDEM/

USGS data sets, although some variables had new maximum 

concentrations. Concentrations of CHLa for periphyton provide a new range because of the small amount of periphyton 

data in the USEPA data set. 

The IDEM/USGS values for TKN fell within the range of 

the published values for Ecoregions VI, IX, 55, and 72 (table 

5). The IDEM/USGS 25th-percentile TKN values were greater 

than the published values for Ecoregions VI, IX, and 55. If the 

proposed USEPA TKN water-quality criteria for Ecoregions 

VI and IX were enacted, of the individual samples collected, 

65.1 percent in Ecoregion VI and 79.2 percent in Ecoregion IX 

would have exceeded those criteria. 

The IDEM/USGS values for nitrate fell within or were 

close to the range of the published values for Ecoregions VI, 

IX, 55, and 72 (table 6). The IDEM/USGS 25th-percentile 

nitrate value was greater than the published value for Ecoregion IX. A higher new maximum concentration was found for 

Ecoregion 55. If the proposed USEPA nitrate water-quality 

criteria for Ecoregions VI and IX were enacted, of the individual samples collected, 60.5 percent in Ecoregion VI and 70.8 

percent in Ecoregion IX would have exceeded those criteria.

Table 5. Total Kjeldahl nitrogen as N values collected in 2001 from the Indiana Department of Environmental Management/

U.S. Geological Survey study and the published U.S. Environmental Protection Agency values for Aggregate Nutrient Ecoregions VI

and IX and Level III Ecoregions 55 and 72.

[All data except number of streams are total Kjeldahl nitrogen as nitrogen values in milligrams per liter; N, nitrogen; IDEM, Indiana Department of Environmental Management; USGS, U.S. Geological Survey; USEPA, U.S. Environmental Protection Agency; shading indicates value exceeds published U.S. Environmental Protection Agency value for Aggregate Nutrient Ecoregions VI and IX, all seasons; bold text indicates value exceeds published U.S. Environmental 

Protection Agency value for Level III Ecoregions 55 and 72 reference conditions, all seasons; nc, not calculated in U.S. Environmental Protection Agency 

Nutrient Criteria documents]

Statistic

IDEM/

USGS 

values

USEPA values, 

all seasons1

IDEM/

USGS 

values

USEPA values, 

all seasons IDEM/

USGS 

values

USEPA values, 

all seasons

Aggregate 

Nutrient

Ecoregion VI2

Level III 

Ecoregion 552

Aggregate 

Nutrient

Ecoregion IX3

Level III 

Ecoregion 723

Number of streams 21 628 198 12 1,609 9 154

Minimum value .335 .025 .050 .280 .000 .280 .025

10th percentile .470 nc nc .280 nc .280 nc

25th percentile .600 .591 .400 .423 .300 .310 .539

50th percentile .800 nc nc .595 nc .635 nc

75th percentile 1.05 nc nc 1.04 nc 1.12 nc

90th percentile 1.55 nc nc 1.30 nc 1.55 nc

Maximum value 2.55 4.50 3.50 1.55 4.83 1.55 4.32 

1

Values are the median of all seasons for all samples collected from a single stream.

2

U.S. Environmental Protection Agency, 2000a.

3

U.S. Environmental Protection Agency, 2000b.
16 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

The IDEM/USGS values for TN fell within or were close 

to the range of the published values for Ecoregions VI, IX, 

55, and 72 (table 7). The IDEM/USGS 25th-percentile TN 

value was greater than the published value for Ecoregion IX. 

New minimum concentrations were found for Ecoregion VI 

and Ecoregion 55 and maximum concentration for Ecoregion 

55. If the proposed USEPA TN water-quality criteria for 

Ecoregions VI and IX were enacted, of the individual samples 

collected, 51.2 percent in Ecoregion VI and 75.0 percent in 

Ecoregion IX would have exceeded those criteria.

The IDEM/USGS values for TP fell within the range of 

the published values for Ecoregions VI, IX, 55, and 72 (table 

8). The IDEM/USGS 25th-percentile TP values were greater 

than the published values for Ecoregion VI, IX, and 55. The 

IDEM/USGS maximum concentrations were all lower than 

the published values for Ecoregions VI, IX, and 55; they 

were about eight times lower for Ecoregion VI. However, the 

IDEM/USGS minimum TP concentrations were higher than 

the published values for Ecoregions IV, IX, 55, and 72. A new 

maximum concentration was recorded for Ecoregion 72. If the 

proposed USEPA TP water-quality criteria for Ecoregions VI 

and IX were enacted, of the individual samples collected, 69.8 

percent in Ecoregion VI and 87.5 percent in Ecoregion IX 

would have exceeded those criteria.

The IDEM/USGS values for mean periphyton CHLa 

provide a new range or expand the range of the published 

values for Ecoregions VI, IX, 55, and 72 (table 9). The 

IDEM/USGS 25th-percentile mean periphyton CHLa value 

was about half of the published value for Ecoregion IX. A 

new maximum concentration was found for Ecoregion IX. If 

the proposed USEPA mean periphyton CHLa water-quality 

criterion for Ecoregion IX were enacted, of the individual 

samples collected, 31.8 percent in Ecoregion IX would have 

exceeded that criterion. No comparison was made for Ecoregion VI because of the lack of published values in the USEPA 

nutrient-criteria document (Environmental Protection Agency, 

2000a).

Table 6. Nitrite plus nitrate as N values collected in 2001 from the Indiana Department of Environmental Management/

U.S. Geological Survey study and the published U.S. Environmental Protection Agency values for Aggregate Nutrient Ecoregions VI and 

IX and Level III Ecoregions 55 and 72.

[All data except number of streams are nitrite plus nitrate as nitrogen values in milligrams per liter; N, nitrogen; IDEM, Indiana Department of Environmental 

Management; USGS, U.S. Geological Survey; USEPA, U.S. Environmental Protection Agency; shading indicates value exceeds published U.S. Environmental 

Protection Agency value for Aggregate Nutrient Ecoregions VI and IX, all seasons; bold text indicates value exceeds published U.S. Environmental Protection 

Agency value for Level III Ecoregions 55 and 72 reference conditions, all seasons; nc, not calculated in U.S. Environmental Protection Agency Nutrient Criteria 

documents]

Statistic

IDEM/

USGS 

values

USEPA values, 

all seasons1

IDEM/

USGS 

values

USEPA values, 

all seasons IDEM/

USGS 

values

USEPA values, 

all seasons

Aggregate 

Nutrient

Ecoregion VI2

Level III 

Ecoregion 552

Aggregate 

Nutrient

Ecoregion IX3

Level III 

Ecoregion 723

Number of streams 21 717 219 12 1,671 9 173

Minimum value .265 .010 .025 .009 .000 .009 .003

10th percentile .412 nc nc .013 nc .009 nc

25th percentile .510 .633 1.60 .214 .125 .018 .215

50th percentile 1.75 nc nc .880 nc .735 nc

75th percentile 2.55 nc nc 1.80 nc 1.30 nc

90th percentile 3.55 nc nc 2.40 nc 4.35 nc

Maximum value 8.40 10.7 8.13 4.35 9.78 4.35 8.63 

1

Values are the median of all seasons for all samples collected from a single stream.

2

U.S. Environmental Protection Agency, 2000a.

3

U.S. Environmental Protection Agency, 2000b.
Drainage-Area and Land-Use Analysis 17

The IDEM/USGS values for mean seston CHLa provide 

a new range or expand the range of the published values for 

Ecoregions VI, IX, 55, and 72 (table 10). The IDEM/USGS 

minimum concentrations were higher than the published values for Ecoregions VI and IX. The IDEM/USGS 25th-percentile mean seston CHLa value was higher than published value 

for Ecoregion 72. If the proposed USEPA mean seston CHLa 

water-quality criteria for Ecoregions VI and IX were enacted, 

of the individual samples collected, 51.2 percent in Ecoregion 

VI and 62.5 percent in Ecoregion IX would have exceeded 

those criteria.

Table 7. Total nitrogen as N values collected in 2001 from the Indiana Department of Environmental Management/

U.S. Geological Survey study and the published U.S. Environmental Protection Agency values for Aggregate Nutrient Ecoregions VI and 

IX and Level III Ecoregions 55 and 72.

[All data except number of streams are total nitrogen as nitrogen values in milligrams per liter; N, nitrogen; IDEM, Indiana Department of Environmental Management; USGS, U.S. Geological Survey; USEPA, U.S. Environmental Protection Agency; shading indicates a new minimum value or exceeds the published 

U.S. Environmental Protection Agency value for Aggregate Nutrient Ecoregions VI and IX, all seasons; bold text indicates a new minimum value or exceeds the 

published U.S. Environmental Protection Agency value for Level III Ecoregions 55 and 72 reference conditions, all seasons; nc, not calculated in U.S. Environmental Protection Agency Nutrient Criteria documents]

Statistic

IDEM/

USGS 

values

USEPA values, 

all seasons1

IDEM/

USGS 

values

USEPA values, 

all seasons IDEM/

USGS 

values

USEPA values, 

all seasons

Aggregate 

Nutrient

Ecoregion VI2

Level III 

Ecoregion 552

Aggregate 

Nutrient

Ecoregion IX3

Level III 

Ecoregion 723

Number of streams 21 77 2 12 274 9 21

Minimum value .745 .885 3.63 .298 .240 .298 .470

10th percentile 1.14 nc nc .323 nc .298 nc

25th percentile 1.54 2.18 3.63 .943 .692 .690 1.67

50th percentile 2.55 nc nc 1.63 nc 1.57 nc

75th percentile 3.50 nc nc 2.46 nc 2.34 nc

90th percentile 5.10 nc nc 2.99 nc 5.90 nc

Maximum value 9.26 10.1 3.78 5.90 12.4 5.90 7.09

1

Values are the median of all seasons for all samples collected from a single stream.

2

U.S. Environmental Protection Agency, 2000a.

3

U.S. Environmental Protection Agency, 2000b.
18 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

Table 8. Total phosphorus as P values collected in 2001 from the Indiana Department of Environmental Management/

U.S. Geological Survey study and the published U.S. Environmental Protection Agency values for Aggregate Nutrient Ecoregions VI and 

IX and Level III Ecoregions 55 and 72.

[All data except number of streams are total phosphorus as phosphorus values in milligrams per liter; P, phosphorus; IDEM, Indiana Department of Environmental Management; USGS, U.S. Geological Survey; USEPA, U.S. Environmental Protection Agency; shading indicates value exceeds published U.S. Environmental Protection Agency value for Aggregate Nutrient Ecoregions VI and IX, all seasons; bold text indicates value exceeds published U.S. Environmental Protection Agency value for Level III Ecoregions 55 and 72 reference conditions, all seasons; nc, not calculated in U.S. Environmental Protection Agency Nutrient 

Criteria documents]

Statistic

IDEM/

USGS 

values

USEPA values, 

all seasons1

IDEM/

USGS 

values

USEPA 

values, 

all seasons IDEM/

USGS 

values

USEPA 

values, 

all seasons

Aggregate 

Nutrient

Ecoregion VI2

Level III 

Ecoregion 552

Aggregate 

Nutrient

Ecoregion IX3

Level III 

Ecoregion 723

Number of streams 21 815 225 12 2,104 9 183

Minimum value .054 .005 .010 .015 .000 .015 .001

10th percentile .060 nc nc .029 nc .015 nc

25th percentile .086 .076 .063 .050 .037 .048 .083

50th percentile .120 nc nc .106 nc .110 nc

75th percentile .170 nc nc .270 nc .350 nc

90th percentile .215 nc nc .370 nc 1.77 nc

Maximum value .285 2.23 1.82 1.77 2.40 1.77 1.60

1

Values are the median of all seasons for all samples collected from a single stream.

2

U.S. Environmental Protection Agency, 2000a.

3

U.S. Environmental Protection Agency, 2000b.
Drainage-Area and Land-Use Analysis 19

Table 9. Mean periphyton chlorophyll a values collected in 2001 from the Indiana Department of Environmental Management/

U.S. Geological Survey study and the published U.S. Environmental Protection Agency values for Aggregate Nutrient Ecoregions VI

and IX and Level III Ecoregions 55 and 72.

[All data except number of streams are mean periphyton chlorophyll a values in milligrams per square meter; IDEM, Indiana Department of Environmental 

Management; USGS, U.S. Geological Survey; USEPA, U.S. Environmental Protection Agency; shading indicates value exceeds published U.S. Environmental 

Protection Agency value for Aggregate Nutrient Ecoregion IX, all seasons; nd, no data collected or published in U.S. Environmental Protection Agency Nutrient 

Criteria documents; nc, not calculated in U.S. Environmental Protection Agency Nutrient Criteria documents] 

Statistic

IDEM/

USGS 

values

USEPA values, 

all seasons1

IDEM/

USGS 

values

USEPA 

values, 

all seasons IDEM/

USGS 

values

USEPA 

values, 

all seasons

Aggregate 

Nutrient

Ecoregion VI2

Level III 

Ecoregion 552

Aggregate 

Nutrient

Ecoregion IX3

Level III 

Ecoregion 723

Number of streams 21 nd nd 12 6 9 nd

Minimum value 8.29 nd nd 2.00 11.0 2.00 nd

10th percentile 9.18 nd nd 7.33 nc 2.00 nd

25th percentile 18.5 nd nd 9.60 20.4 9.33 nd

50th percentile 35.4 nd nd 19.3 nc 10.6 nd

75th percentile 52.2 nd nd 46.5 nc 51.2 nd

90th percentile 89.6 nd nd 103 nc 197 nd

Maximum value 207 nd nd 197 62.0 197 nd

1

Values are the median of all seasons for all samples collected from a single stream.

2

U.S. Environmental Protection Agency, 2000a.

3

U.S. Environmental Protection Agency, 2000b.
20 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

Table 10. Mean seston chlorophyll a values collected in 2001 from the Indiana Department of Environmental Management/

U.S. Geological Survey study and the published U.S. Environmental Protection Agency values for Aggregate Nutrient Ecoregions VI

and IX and Level III Ecoregions 55 and 72.

[All data except number of streams are mean seston chlorophyll a values in micrograms per liter; IDEM, Indiana Department of Environmental Management; 

USGS, U.S. Geological Survey; USEPA, U.S. Environmental Protection Agency; bold text indicates a new minimum value or exceeds the published U.S. Environmental Protection Agency value for Level III Ecoregions 55 and 72 reference conditions, all seasons; nd, no data collected or published in U.S. Environmental Protection Agency Nutrient Criteria documents; nc, not calculated in U.S. Environmental Protection Agency Nutrient Criteria documents]

Statistic

IDEM/

USGS 

values

USEPA values, 

all seasons1

IDEM/

USGS 

values

USEPA 

values, 

all seasons IDEM/

USGS 

values

USEPA 

values, 

all seasons

Aggregate 

Nutrient

Ecoregion VI2

Level III 

Ecoregion 552

Aggregate 

Nutrient

Ecoregion IX3

Level III 

Ecoregion 723

Number of streams 21 63 nd 12 71 9 2

Minimum value .699 .250 nd 1.07 .225 1.07 1.50

10th percentile 1.03 nc nd 1.36 nc 1.07 nc

25th percentile 1.58 2.70 nd 1.84 2.25 2.29 1.50

50th percentile 4.54 nc nd 2.89 nc 3.04 nc

75th percentile 4.96 nc nd 5.93 nc 7.25 nc

90th percentile 6.83 nc nd 15.0 nc 15.8 nc

Maximum value 28.7 47.6 nd 15.8 36.7 15.8 6.55 

 1Values are the median of all seasons for all samples collected from a single stream.

2

U.S. Environmental Protection Agency, 2000a.

3

U.S. Environmental Protection Agency, 2000b.
Conclusions, Acknowledgments, and References 21

Conclusions

Excessive inputs of nutrients into streams have humanhealth, economic, and ecological consequences. In 2000, the 

U.S. Environmental Protection Agency (USEPA) proposed 

nutrient water-quality criteria to protect streams from excess 

nutrients. This report is one of several reports done as a cooperative effort between Indiana Department of Environmental 

Management (IDEM) and the U.S. Geological Survey (USGS) 

to collect new data to assist IDEM in determination of nutrient 

criteria. Data were gathered from July through September 

2001 at 34 randomly selected sites in the West Fork White 

River Basin, Indiana, for algal biomass, habitat, nutrients, and 

biological communities (fish and invertebrates). Basin characteristics (land use and drainage area) and biological-community attributes and metric scores were determined for the basin 

of each sampling site. Yearly Principal Components Analysis 

site scores were calculated for algal-biomass (periphyton and 

seston). The yearly Principal Components Analysis site scores 

for the first axis (PC1) were related using Spearman’s rho 

to the algal-biomass, habitat, basin-characteristics, nutrient, 

biological-community attribute and metric score data. Summer 

(July) appears to be the best time to sample to find significant relations between seston PC1 and nutrient variables and 

fish-community attributes and metric scores. From the initial 

analysis, fish- and invertebrate-community attributes and metric scores may reflect the impacts of increased algal-biomass 

associated with high concentrations of nutrients. 

The periphyton PC1 site score, which was most influenced by ash-free dry mass (AFDM), was negatively related to 

one habitat variable (percent closed canopy). The periphyton 

PC1 site scores were positively related to one fish-community 

attribute (percent tolerant); one invertebrate-community attribute, Ephemeroptera, Plecoptera, and Trichoptera (EPT index); 

and one invertebrate-community metric score (EPT index 

metric score). The periphyton PC1 was not related to the basin 

characteristics or nutrients.

The seston PC1 site score, which was most influenced 

by particulate organic carbon, was negatively related to two 

nutrient variables: total Kjeldahl nitrogen (July) and total 

phosphorus (July). The seston PC1 site scores were negatively 

related to one fish-community attribute (large-river percent) 

and one invertebrate-community attribute (EPT-to-total ratio). 

The seston PC1 was not related to the habitat or basin-characteristic data.

To understand how the choice of sampling sites might 

have affected the results, an analysis of the drainage area 

and land use was done. Of the 34 sites sampled in the West 

Fork White Basin, 61.8 percent were headwater streams (less 

than 50 km2); all of the sites were wadeable, small streams 

less than 854 km2. No boat sites were sampled and the lack 

of large streams may explain the lack of relations with basin 

size. The dominant mean land use of the sites sampled was 

agriculture (81.0 percent), followed by forest (10.5 percent) 

and urban (7.5 percent). Of the streams that were sampled, 71 

percent of the sites had at least 76 percent agricultural land 

use in the basin. This lack of an agricultural land-use gradient 

potentially could mask relations among the PC1 site scores 

(periphyton and seston) and the environmental variables and 

biological-community (fish and invertebrates) attributes and 

metric scores.

The values for nutrients (nitrate, TKN, TN, and TP) and 

chlorophyll a (CHLa) (periphyton and seston) were compared 

to published USEPA values for the respective ecoregions. 

CHLa (periphyton and seston) values were either greater than 

the 25th-percentile published USEPA values or extended data 

ranges in Aggregate Nutrient and Level III Ecoregions. If the 

values for the 25th percentile proposed by the USEPA were 

adopted as nutrient water-quality criteria, the percentage of 

samples in the West Fork White River Basin that would have 

exceeded these criteria ranged from 31.8 percent in Ecoregion 

IX for periphyton CHLa to 87.5 percent in Ecoregion IX for 

TP.

Acknowledgments

The authors thank Indiana Department of Environmental Management and U.S. Geological Survey personnel for 

collecting and processing the data. We also thank Patricia H. 

Long and Donald R. Leer of the USGS for editorial support, 

and Julie Hambrook Berkman of the USGS Ohio Water Science Center and Billy Justus of the USGS Arkansas Water 

Science Center for their technical reviews of the manuscript. 

Projects of this type are a team effort and could not have been 

completed without the efforts of the IDEM and USGS personnel, which are sincerely appreciated.

References

Arar, E.J., and Collins, G.B., 1997, In vitro determination of 

chlorophyll a and phaeophytin a in marine and freshwater 

algae by fluorescence (revision 1.2): U.S. Environmental 

Protection Agency, National Exposure Research Laboratory, Office of Research and Development, Cincinnati, 22 

p., accessed April 15, 2001, at www.epa.gov/nerlcwww/

m445_0.pdf

Baker, N.T., and Frey, J.W., 1997, Fish community and habitat data at selected sites in the White River Basin, Indiana, 1993–95: U.S. Geological Survey Open-File Report 

96–653A, 44 p.

Barbour, M.T., Gerritsen, Jeroen, Snyder, B.D., and Stribling, J.B., 1999, Rapid bioassessment protocols for use in 

streams and wadeable rivers—Periphyton, benthic macroinvertebrates and fish (2d. ed.): EPA 841–B–99–002, 

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

Washington, D.C.
22 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

Beckman, Timothy, ed., 2000, Surveys Section field procedure manual (revised April 2000): Indiana Department 

of Environmental Management, Office of Water Management, Assessment Branch, Surveys Section, IDEM 

032/02/006/2000, 70 p.

Bowren, Timothy, and Ghiasuddin, Syed, 1999, Quality assurance project plan for Indiana surface water quality monitoring programs (revision 2), June 1999: Indiana Department 

of Environmental Management, IDEM/32/01/1442/1999, 

70 p.

Britton, L.J., ed., and Greeson, P.E., 1988, Methods for collection and analysis of aquatic biological and microbiological 

samples: U.S. Geological Survey Techniques of WaterResources Investigations, book 5, chap. A4, 685 p.

Carpenter, K.D., and Waite, I.R., 2000, Relations of habitatspecific algal assemblages to land use and water chemistry 

in the Willamette Basin, Oregon: Environmental Monitoring 

and Assesment v. 64, p. 247–257.

Caskey, B.J., 2003, Relations of stream fish communities to 

physical and chemical parameters and land use in the Mississippi Alluvial Plain Ecoregion. U.S. Geological Survey 

Open-File Report OFR-03-31, 31 p.

Caskey, B.J., Frey, J.W., and Lowe, B.S., in press, Relations of 

principal component analysis site scores to algal-biomass, 

habitat, basin-characteristics, nutrient, and biologicalcommunity data in the Whitewater River and East Fork 

White River Basins, Indiana, 2002: U.S. Geological Survey 

Scientific Investigations Report 2007-5229.

Charles, Donald, Winter, Diane, and Hoffman, Michael, 2000, 

Field sampling procedures for the New Jersey Algae Indicators Project (revision 0[9/00]): Academy of Natural Sciences, Patrick Center for Environmental Research, Procedure No. P–13–64, 9 p.

Dufour, R.L., 2002, Guide to appropriate metric selection for 

calculating the Index of Biotic Integrity (IBI) for Indiana 

rivers and streams: Indiana Department of Environmental 

Management, Office of Water Quality, Assessment Branch, 

Biological Studies Section, accessed September 15, 2005, at 

http://www.in.gov/idem/water/assessbr/biostud/ibiflowchrt.

pdf

Frey, J.W., and Caskey, B.J., 2007, Nutrient, habitat, and 

basin-characteristics data and relations with fish- and 

invertebrate communities in Indiana streams, 1998–2000: 

U.S. Geological Survey Scientific Investigations Report 

2007–5076, 40 p.

Gauch, H.G., 1982, Multivariate analysis in community ecology: Cambridge University Press, United Kingdom, 298 p.

Hogatt, R.E., 1975, Drainage areas of Indiana streams: U.S. 

Geological Survey, Water Resources Division, 231 p.

Indiana Department of Environmental Management, 1992, 

Standard operating procedures—Appendices of operational 

equipment manuals and procedures (revision 1): Indiana 

Department of Environmental Management, Office of Water 

Management, Biological Studies Section, Surveillance and 

Standards Branch, IDEM/OWM/WQSSB/BSS–SOP [various pagination].

Indiana Department of Environmental Management, 1999, 

Summary of protocols: Probability based site assessment 

for Watershed Program field activities (revision 6): Indiana 

Department of Environmental Management, Office of Water 

Quality, Assessment Branch, IDEM 32/03/002/1999, 32 p.

Indiana Department of Environmental Management, 2001, 

Surface water quality monitoring strategy (revision September 2001): Indiana Department of Environmental Management, Office of Water Quality, Assessment Branch, IDEM 

32/01/016/1998, 3 p.

Jongman, R.H.G., Ter Braak, C.J.F., and Van Tongren, O.F.R., 

1995, Data analysis in community and landscape ecology: 

Cambridge University Press, United Kingdom, 299 p.

Jordan, T.E., Correll, D.L., and Weller, D.E., 1993, Nutrient 

interception by a riparian forest receiving inputs from adjacent cropland: Journal of Environmental Quality, 

v. 22, p. 467–473.

Leer, D.R, Caskey, B.J., Frey, J.W., and Lowe, B.S., 2007, 

Relations of principal components analysis site scores to 

algal-biomass, habitat, basin-characteristics, nutrient, and 

biological-community data in the Upper Wabash River 

Basin, Indiana, 2003: U.S. Geological Survey Scientific 

Investigations Report 2007-5231, 25 p. 

McCune, B. and Grace, J.B., 2002, Analysis of ecological 

communities: MjM Software Design, Gleneden Beach, 

Ore., USA, 300 p.

Miltner, R.J., and Rankin, E.T., 1998, Primary nutrients and 

the biotic integrity of rivers and streams: Freshwater Biology, v. 40, p. 143–158.

Mueller, D. K., and Helsel, D.R., 1996, Nutrients in the 

Nation’s waters—Too much of a good thing?: U.S. Geological Survey Circular 1136, 24 p.

Munn, M.D., and Hamilton, P.A., 2003, New studies intiated 

by the U.S. Geological Survey—Effects of nutrient enrichment on stream ecosystems: U.S. Geological Survey FactSheet FS–118–03, 4 p.

National Research Council, 1978, Nitrates—An environmental 

assessment: Washington, D.C., National Academy of Sciences, 723 p.
References 23

Ohio Environmental Protection Agency, 1999, Association 

between nutrients, habitat, and the aquatic biota in Ohio 

rivers and streams: Ohio Environmental Protection Agency 

Technical Bulletin MAS/1999–1–1, 78 p.

Porter, S.D., Cuffney, T.F., Gurtz, M.E., and Meador, M.R., 

1993, Methods for collecting algal samples as part of the 

National Water-Quality Assessment Program: 

U.S. Geological Survey Open-File Report 93–409, 39 p.

Primer-E Ltd, 2006, Primer User Manual / Tutorial (version 6): Plymouth Marine Laboratory, United Kingdom, 

111–119 p.

Ries, K.G., III, Steeves, P.A., Coles, K.D., Rea, A.H., and 

Stewart, D.W., 2004, Stream Stats: A U.S. Geological Survey web application for stream information: U.S. Geological Survey Fact Sheet, FS 2004–3115, 4 p.

Schnoebelen, D.J., Fenelon, J.M., Baker, N.T., Martin, J.D., 

Bayless, E.R., Jacques, D.V., and Crawford, C.G., 1999, 

Environmental setting and natural factors and human influences affecting water quality in the White River Basin, 

Indiana: U.S. Geological Survey Water-Resources Investigations Report 97–4260, 66 p.

Shelton, L.R., 1994, Field guide for collecting and processing stream-water samples for the National Water-Quality 

Assessment Program: U.S. Geological Survey Open-File 

Report 94–455, 646 p.

Simon, T. P., 1991, Development of index of biotic expectations for the ecoregions of Indiana, I. Central Corn Belt 

Plain: U.S. Environmental Protection Agency, Region V, 

Environmental Sciences Division, Monitoring and Quality 

Assurance Branch: Ambient Monitoring Section, Chicago, 

Ill., EPA905/9–9/025, 93 p.

Stewart, J.A., Keeton, C.R., Hammil, L.E., Nguyen, H.T., and 

Majors, D.K., 2002, Water resources data, Indiana, water 

year 2001: U.S. Geological Survey Water-Data Report 

IN–01–1, 678 p.

U.S. Census Bureau, GCT-PH1, Population, housing 

units, area, and density—2000, Indiana: accessed 

March 21, 2005, at http://factfinder.census.gov/servlet/

GCTTable?_bm=y&-context=gct&-ds_name=DEC_2000_

SF1_U&-CONTEXT=gct&-mt_name=DEC_2000_SF1_U_

GCTPH1_ST4&-tree_id=4001&-redoLog=true&-_

caller=geoselect&-geo_id=04000US18&-format=ST7|ST-7S&-_lang=en

U.S. Environmental Protection Agency, 1997a, National 

water quality inventory 1996—Report to Congress: U.S. 

Environmental Protection Agency, Office of Water, EPA 

841–R–97–008, 527 p.

U.S. Environmental Protection Agency, 1997b, Level III 

ecoregions of the conterminous United States (revision of 

Omernik, 1987): Corvallis, Oreg., U.S. Environmental Protection Agency, National Health and Environmental Effects 

Research Laboratory Map M–1, various scales.

U.S. Environmental Protection Agency, 2000a, Ambient water 

quality criteria recommendations—Information supporting 

the development of state and tribal nutrient criteria—Rivers 

and streams in Nutrient Ecoregion VI: U.S. Environmental 

Protection Agency, Office of Water, EPA 822–B–00–017.

U.S. Environmental Protection Agency, 2000b, Ambient 

water quality criteria recommendation—Information supporting the development of state and tribal nutrient criteria—Rivers and streams in Nutrient Ecoregion IX: U.S. 

Environmental Protection Agency, Office of Water, EPA 

822–B–00–019.

U.S. Environmental Protection Agency, 2005, Water quality criteria—Current national recommended water quality 

criteria: accessed September 15, 2005, at http://www.epa.

gov/waterscience/criteria/wqcriteria.html

U.S. Geological Survey, 2000, The national land cover dataset 

1992 (NLCD): accessed August 27, 2005, at

http://seamless.usgs.gov

Vannote, R.L., Minshall, G.W., Cummins, K.W., Sedell, J.R., 

and Cushing, C.E., 1980, The river continuum concept: 

Canadian Journal of Fisheries and Aquatic Sciences, 

v. 37, p. 130–137.

Van Sickle, John, 2003, Analyzing correlations between 

stream and watershed attributes: Journal of American Water 

Resources Association, v. 39, p. 717–726.

Voelker, D.C, 2003, Biological assessment of streams in the 

Indianapolis metropolitan area, Indiana, 1999–2001: U.S. 

Geological Survey Water-Resources Investigations Report 

03–4331, p. 7.

Wang, Lizhu, Lyons, John, Kanehl, Paul, and Gatti, Ronald, 

1997, Influences of watershed land use on habitat quality and biotic integrity in Wisconsin streams: Fisheries 

22:6–12.
24 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

Appendix 1. Metrics used by Indiana Department of Environmental Management for habitat, fish, and invertebrates (Dufour, 2002).

Metrics1 Definition

Habitat 

SubstrateScore A metric to evaluate substrate type, origin, silt cover, and embeddedness.

InstreamCoverScore Instream cover types and the amount (availability) of instream cover.

ChannelMorphologyScore Quality of the stream channel related to the creation and stability of instream habitat (channel 

sinuosity, channel development, channelization, stability, and modifications).

RiparianZoneandBankErosionScore Quality of the riparian buffer zone and flood-plain vegetation, looking at riparian width, 

predominant surrounding land uses, and bank-erosion status.

PoolGlideQualityScore Quality of pool/glide taking into account maximum pool depth, morphology, and velocity.

RiffleRunQualityScore Quality of riffle/run, taking into account riffle/run depth, substrate, and embeddedness.

GradientScore A measure of the influence of gradient and stream size on the biological community and available 

habitat.

Fish2

SpeciesCount Number of species, excluding hybrid species (exclude gizzard shad if in the Wabash River 

mainstem and drainage area is greater than 5,180 square kilometers).

DMS_SpeciesCount Number of darter, madtom, and sculpin species, excluding hybrid species.

Darter_SpeciesCount Number of darter species, excluding hybrid species.

Headwater_Percent Percent of headwater individuals.

LargeRiver_Percent Percent of large river individuals (exclude gizzard shad if in the Wabash River mainstem and 

drainage area greater than 5,180 square kilometers).

Sunfish_SpeciesCount Number of sunfish species, excluding hybrid species.

Centrarchid_SpeciesCount Number of centrarchidae species, excluding hybrid species. 

Minnow_SpeciesCount Number of minnow species, excluding hybrid species.

Sucker_SpeciesCount Number of sucker species, excluding hybrid species. 

RoundBodySucker_SpeciesCount Number of round-body sucker species, excluding hybrid species.

Salmonid_SpeciesCount Number of salmonid species, excluding hybrid species.

Sensitive_SpeciesCount Number of sensitive species, excluding hybrid species.

Tolerant_Percent Percent of tolerant individuals (exclude gizzard shad if in the Wabash River mainstem and drainage 

area greater than 5,180 square kilometers).

Omnivore_Percent Percent of omnivore individuals (exclude gizzard shad if in the Wabash River mainstem and 

drainage area greater than 5,180 square kilometers).

Insectivore_Percent Percent of insectivore or invertivore individuals (exclude gizzard shad if in the Wabash River 

mainstem and drainage area greater than 5,180 square kilometers).

Pioneer_Percent Percent of pioneer individuals.

Carnivore_Percent Percent of carnivore or piscivore individuals (exclude gizzard shad if in the Wabash River 

mainstem and drainage area greater than 5,180 square kilometers).

CatchPerUnitEffort Catch per unit effort (CPUE) or total number of individuals.

CPUElessShads Catch per Unit Effort (CPUE), excluding the number of gizzard shad individuals if in the Wabash 

River mainstem and drainage area greater than 5,180 square kilometers).

SimpleLithophil_Percent Percent of simple lithophilic species (exclude gizzard shad if in the Wabash River mainstem and 

drainage area greater than 5,180 square kilometers).

DELT_Percent

Percent of individuals with deformities, eroded fins, lesions, and tumors (DELT), including 

multiple DELTs (exclude gizzard shad if in the Wabash River mainstem and drainage area 

greater than 5,180 square kilometers).
Appendix 25

Appendix 1. Metrics used by Indiana Department of Environmental Management for habitat, fish, and invertebrates (Dufour, 2002).—

Continued

Metrics1 Definition

Invertebrates

Family Level HBI Summation of the tolerance value times the number of individuals for a specific family 

divided by the total count of individuals for families with a tolerance value.

Number of Taxa Number of families identified in the subsample.

Number of Individuals Total number of individuals for all families identified in the subsample.

Percent Dominant Taxa Highest number of individuals for a given family divided by the total number of individuals in 

the subsample.

EPT Index Total number of families represented in the orders Ephemeroptera, Plecoptera, and 

Trichoptera.

EPT Count Total number of individuals for orders Ephemeroptera, Plecoptera, and Trichoptera.

EPT Count to Total Number of Individuals Total number of individuals for orders Ephemeroptera, Plecoptera, and Trichoptera divided by 

the total number of individuals in the subsample.

EPT Count to Chironomid Count Total number of individuals for orders Ephemeroptera, Plecoptera, and Trichoptera divided by 

the total number of chironomidae.

Chironomid Count Total number of chironomids in the subsample.

Total Number of Individuals to Number of 

Squares Sorted

Total number of individuals in the subsample divided by the number of squares needed to 

reach the total number of individuals.

1

Each of the fish- and invertebrate community metrics also has a corresponding attribute with the same name but consists of the raw data. 

2

 Specific fish species associated with each metric can be found in Dufour, 2002. 
26 Relations of PCA Site Scores in the West Fork White River Basin, Indiana, 2001

Frey, Caskey, and Lowe—Relations of Principal Components Analysis Site Scores to Algal-Biomass, Habitat, Basin-Characteristics, Nutrient, and BiologicalCommunity Data in the West Fork White River Basin, Indiana, 2001—Scientific Investigations Report 2007–5222

Printed on recycled paper