Prepared in cooperation with the U.S. Bureau of Reclamation 

Physical and Chemical Characteristics Including Total and 

Geochemical Forms of Phosphorus in Sediment from the 

Top 30 Centimeters of Cores Collected in October 2006 at 

26 Sites in Upper Klamath Lake, Oregon

Open-File Report 2011–1168

U.S. Department of the Interior

U.S. Geological Survey
Cover: Coring operations during the October 2006 collection of sediment cores 

from Upper Klamath Lake, Oregon. 
ii

Prepared in cooperation with the U.S. Bureau of Reclamation

Physical and Chemical Characteristics Including Total and 

Geochemical Forms of Phosphorus in Sediment from the 

Top 30 Centimeters of Cores Collected in October 2006 at 

26 Sites in Upper Klamath Lake, Oregon

By Nancy S. Simon and Sarah N. Ingle

Open-File Report 2011–1168

U.S. Department of the Interior

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

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2011 

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Suggested citation:

Simon, N.S., and Ingle, S.N., 2011, Physical and chemical characteristics including total and geochemical forms of 

phosphorus in sediment from the top 30 centimeters of cores collected in October 2006 at 26 sites in Upper Klamath

Lake, Oregon: U.S. Geological Survey Open-File Report 2011–1168, 49 p., available only at

http://pubs.usgs.gov/of/2011/1168/.

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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 material contained within this report. 

iii
iv

Contents

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

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

Lakebed Phosphorus: A Controlling Factor for Water Quality in Upper Klamath Lake.............................................. 2

Problem...................................................................................................................................................................... 3

Objectives .................................................................................................................................................................. 3

Purpose and Scope ................................................................................................................................................... 4

Study Design and Methods............................................................................................................................................ 4

Sampling Locations.................................................................................................................................................... 4

Sample Collection...................................................................................................................................................... 4

Sample Preparation ................................................................................................................................................... 4

Sample Analysis ........................................................................................................................................................ 5

Sediment pH........................................................................................................................................................... 5

Microwave-Assisted Digestion of Sediment Samples............................................................................................. 5

Total Phosphorus ................................................................................................................................................... 5

Sequential Extraction ............................................................................................................................................. 6

Carbon and Nitrogen Concentrations ..................................................................................................................... 6

Metals Analysis (Aluminum, Calcium, Iron, and Titanium)...................................................................................... 6

Physical and Chemical Characteristics of Lakebed Sediment ....................................................................................... 6

Water Content and Particle Size ................................................................................................................................ 7

Distribution of Phosphorus, Geochemical Fractions of Phosphorus and Chemical Constituents............................... 7

Summary ....................................................................................................................................................................... 7

References Cited........................................................................................................................................................... 8

Acknowledgments ........................................................................................................................................................10

Figures

1. Map showing location of Upper Klamath Lake, Oregon, and sampling sites ...................................................11

2. Flow chart of sequential extraction procedure used to separate inorganic phosphorus (P) from sediment 

samples collected in October 2006 from Upper Klamath Lake, Oregon. .........................................................12

Tables

1. Comparison of concentrations of total and inorganic phosphorus (P) in sediment from cores collected October 

2006 from Upper Klamath Lake, Oregon, with other data from reports in the literature...................................13

2. Analytical data for sediment cores collected October 24–26, 2006, from Upper Klamath Lake, Oregon.........14

3. Names and locations of sampling sites where sediment cores were collected on October 24–26, 2006, from 

Upper Klamath Lake, Oregon ..........................................................................................................................48

4. Analytical reporting limits for bed sediments....................................................................................................49
v

Conversion Factors

SI to Inch/Pound

Multiply By To obtain

Length

centimeter (cm) 0.3937 inch (in.)

millimeter (mm) 0.03937 inch (in.)

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi)

Area

square meter (m2) 0.0002471 acre 

square kilometer (km2) 247.1 acre

square centimeter (cm2) 0.001076 square foot (ft2)

square meter (m2) 10.76 square foot (ft2) 

square centimeter (cm2) 0.1550 square inch (ft2) 

square kilometer (km2) 0.3861 square mile (mi2)

Volume

liter (L) 1.057 quart (qt)

liter (L) 0.2642 gallon (gal)

cubic meter (m3) 264.2 gallon (gal) 

cubic decimeter (dm3) 0.2642 gallon (gal) 

cubic centimeter (cm3) 0.06102 cubic inch (in3) 

cubic decimeter (dm3) 61.02 cubic inch (in3) 

liter (L) 61.02 cubic inch (in3) 

cubic decimeter (dm3) 0.03531 cubic foot (ft3) 

cubic meter (m3) 35.31 cubic foot (ft3)

Mass

kilogram (kg) 2.205 pound avoirdupois (lb)

megagram (Mg) 1.102 ton, short (2,000 lb)

megagram (Mg) 0.9842 ton, long (2,240 lb)

Density

gram per cubic centimeter (g/cm3) 62.4220 pound per cubic foot (lb/ft3)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows: °F=(1.8×°C)+32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:°C=(°F-32)/1.8

Concentrations of chemical constituents in water are given either in milligrams per liter (mg L-1) or micrograms per liter (μg L-1). 

Use of liter (L) as a special name for cubic decimeter (dm3) is restricted to the measurement of liquids and gases.
1

Physical and Chemical Characteristics Including Total and 

Geochemical Forms of Phosphorus in Sediment from the 

Top 30 Centimeters of Cores Collected in October 2006 at 

26 Sites in Upper Klamath Lake, Oregon

By Nancy S. Simon and Sarah N. Ingle

Abstract

This study of phosphorus (P) cycling in eutrophic Upper Klamath Lake (UKL), Oregon (Oreg.)

was conducted by the U.S. Geological Survey in cooperation with the U.S. Bureau of Reclamation. 

Lakebed sediments from the upper 30-cm of cores collected from 26 sites were characterized. Cores 

were sampled at 0.5, 1.5, 2.5, 3.5, 4.5, 10, 15, 20, 25, and 30 cm. Prior to freezing, water content and 

sediment pH were determined. After being freeze-dried, all samples were separated into greater than 

63-micron (μm) particle-size (coarse) and less than 63-μm particle-size (fine) fractions. In the surface 

samples (0.5 to 4.5 cm below the sediment water interface), approximately three-fourths of the particles 

were larger than 63-μm. The ratios of the coarse particle-size fraction (>63 μm) and the fine particlesize fraction (<63 μm) were approximately equal in samples at depths greater than 10 cm below the 

sediment water interface. 

Chemical analyses included both size fractions of freeze-dried samples. Chemical analyses 

included determination of total concentrations of aluminum (Al), calcium (Ca), carbon (C), iron (Fe), 

poorly crystalline Fe, nitrogen (N), P, and titanium (Ti). Total Fe concentrations were the largest in 

sediment from the northern portion of UKL, Howard Bay, and the southern portion of the lake. 

Concentrations of total Al, Ca, and Ti were largest in sediment from the northern, central, and 

southernmost portions of the lake and in sediment from Howard Bay. Concentrations of total C and N 

were largest in sediment from the embayments and in sediment from the northern arm and southern 

portion of the lake in the general region of Buck Island. Concentrations of total C were larger in the 

greater than 63-μm particle-size fraction than in the less than 63-μm particle-size fraction. 

Sediments were sequentially extracted to determine concentrations of inorganic forms of P, 

including loosely sorbed P, P associated with poorly crystalline Fe oxides, and P associated with 

mineral phases. The difference between the concentration of total P and sum of the concentrations of 

inorganic forms of P is referred to as residual P. Residual P was the largest fraction of P in all of the 

sediment samples. In UKL, the correlation between concentrations of total P and total Fe in sediment is 

poor (R2

<0.1). The correlation between the concentrations of total P and P associated with poorly 

crystalline Fe oxides is good (R2=0.43) in surface sediment (0.5 to 4.5 cm below the sediment water 

interface) but poor (R2<0.1) in sediments at depths between 10 cm and 30 cm. Phosphorus associated 

with poorly crystalline Fe oxides is considered bioavailable because it is released when sediment 

conditions change from oxidizing to reducing, which causes dissolution of Fe oxides. 
2

Introduction

The estimated internal load of phosphorus (P) is larger than the calculated external load of P to 

Upper Klamath Lake (UKL). Only one-third of the total load of P to UKL has been determined to come 

from external sources (Oregon Department of Environmental Quality, 2002). Discussions of 

remediation efforts for eutrophic UKL focus on attenuation of the internal load of P from bottom 

sediments. Several reports of chemical data including concentrations of P sediment cores have appeared 

in the literature (Sanville and others, 1974; Wildung and others, 1977; Klamath Consulting Service, 

Inc., 1983; Eilers and others, 2001; Simon and others, 2009) (table 1). None of these reports includes a 

set (collected on the same date) of cores collected from multiple sites that is representative of the lake as 

a whole. This report provides a snapshot of the distribution of total P, geochemical forms of P, and other 

chemical constituents in sediment cores from sampling sites distributed areally in UKL. 

Lakebed Phosphorus: A Controlling Factor for Water Quality in Upper Klamath 

Lake 

A National Research Council report found that large-scale adult mortality of two endangered 

sucker species in Upper Klamath Lake (UKL), Oregon (Oreg.), was attributable to large zones of 

hypoxia resulting from organic decomposition following blooms of the nitrogen (N)-fixing cyanophyte 

Aphanizomenon flos-aquae (AFA) (National Research Council, 2004). The algal biomass, with its 

associated P, settles in the water column when large blooms of AFA senesce (decline or collapse). 

When microorganisms use oxygen dissolved in lake water to decompose algal biomass, dissolved 

oxygen concentrations in the water column drop to levels insufficient to support fish respiration. The

availability of phosphorus (P) is considered the controlling factor in development of algal blooms in 

UKL (National Research Council, 2004). Management of P concentrations in the water column is 

considered directly related managing the size and composition of algal blooms 

To evaluate the benefits of remediation actions in the watershed and wetlands, including the 

reduction of external loads of P, and to obtain realistic expectations for recovery time in the ecosystem, 

it is important to understand processes controlling internal loading and to determine amounts and forms 

of P stored in the lake sediment. 

Although studies have addressed the degree to which anthropogenic factors affected the structure 

and function of the natural marshes of UKL, the delivery of nutrient loads to the lake, as well as the 

effect of hydraulic operations on lake water quality and resident aquatic life, little definitive work has 

been done to quantitatively estimate the amount of total P contained within the lakebed sediment, or 

more importantly, the bioavailability of P within the sediment. This reservoir of P within the sediment is 

thought to be the cause of a large internal P load in the lake water each year that results in increased 

eutrophic impacts (that is, nuisance levels of algae). AFA has been the dominant form of algae in the 

lake since the 1960s (Dileanis and others, 1996). Blooms of this algae result in extremely high pH and 

low dissolved-oxygen levels in the water column that are likely influencing fish productivity. The 

Oregon Department of Environmental Quality (2002) states that P reduction is the most effective, longterm nutrient management option used to control algal biomass in UKL. 

Even with stringent TMDLs on inflowing P loads from the tributaries to UKL, the potentially 

large internal supply of P from the lakebed could produce highly eutrophic conditions for years or even 

decades to come (Marsden, 1989; Kleeberg and Kozerski, 1997). Upper Klamath Lake is a large, 

shallow lake with a mean depth of 2.8 m full pool (Wood and others, 2008). Following external nutrient 

reduction, shallow lakes tend to be more resistant to recovery than deep lakes (Phillips and others, 2005; 
3

Kleeberg and Kozerski, 1997). The current TMDL for P is based, in part, on the hypothesis that P bound 

to Fe in lakebed sediments will be released rapidly when water column pH rises because of the

consumption of carbon dioxide in lake water by multiplying algae, whose growth is fueled by the 

external loading of P. Work by Fisher and Wood (2004), however, shows that the release of P from bed 

sediment at higher pH levels could explain no more than 10% of the annual internal loading of 

phosphorus. Therefore, mechanisms other than those that are being used as the basis for the TMDL are 

likely controlling the internal release of P into the lake water. The success of the total maximum daily 

load (TMDL) requirements for UKL is related to whether the model used for internal loading is correct.

Problem

The addition of P from the sediment to the water column occurs at the sediment water interface. 

Algal cells accumulate on surficial sediment when blooms of the cyanophyte AFA die. When organic 

matter at depth in the sediment is microbially degraded, the P released in the degradation process is 

added to sediment interstitial water, creating larger interstitial water concentrations of P and a 

concentration gradient that results in diffusion of P upward towards the sediment water interface. The 

deposition of algal debris on the sediment surface and the diffusion of P from depth in sediments results 

in an increase in P concentrations in the surface layers (<5 cm) of lake bottom. The reservoir of total P 

in the upper 5 cm of the lakebed most likely will continue to contribute to the annual internal load of P 

for years to come (Marsden, 1989; Kleeberg and Kozerski, 1997). Determination of P concentrations in 

the deeper sediments (dating back to the 1800s) provides data to estimate the natural background 

concentration of P in UKL sediments The background concentrations might be subtracted from P 

concentrations measured in the upper 5 cm of sediment to determine how much of the P in the surface 

sediments has been added in modern times. 

The analyses done in this study included determining the concentrations of explanatory 

indicators in sediment samples. The distributions of concentrations of Al and Ti in sediment cores assist 

investigators in determining changes in the historic delivery of sediments and P from tributaries to the 

body of a lake. Because Al and Ti have terrestrial sources, concentrations of Al and Ti in sediments can 

be used to estimate the contribution of detrital mineral matter to lake bottom sediments.

Previous work by the U.S. Geological Survey (USGS) in UKL has provided some insight into 

possible mechanisms involving the loss and (or) accumulation of P in bottom sediments. Simon and 

others (2009) report that in a study of cores in 2005 from four sites in UKL (fig. 1), concentrations of P 

in sequentially extracted geochemical phases changed during the period between the onset (April) and 

development (July) of an AFA bloom. They found that in the cores collected at the Bare Island site, P 

concentrations associated with poorly crystalline Fe oxides in the surficial sediment decreased between 

April and July. This finding indicates that sediment in the vicinity of Bare Island might be actively 

contributing to the internal loading of P during an AFA bloom. Conversely, however, the cores 

collected by these investigators at the Mid Lake site had essentially no Fe-bound P and concentrations 

of organic P increased appreciably between April to July. The data from Simon and others (2009) 

provided some insight into mechanisms and intersite variability of P release, but their study indicated 

that a significant number of cores needed to be collected and analyzed in a systematic and representative 

way to characterize the geospatial extent and the principle mechanism(s) contributing to the internal

loading of P from bed sediment to lake water. 

Objectives

Task 1 – Determine the mass (reservoir) of total P in the sediment column between the sedimentwater interface and 30 cm below the sediment-water interface in sediment cores collected from UKL to 
4

evaluate the geospatial distribution of P in UKL lake sediment over approximately the last 100 years. 

Phosphorus analyses presented in this report include the determination of total P concentrations and 

concentrations of forms of P, determined by chemical extractions of sediment samples. Concentrations 

of forms of inorganic P, which includes loosely bound P, P associated with poorly crystalline Fe oxides, 

and P minerals, will be summed and subtracted from concentrations of total P. This difference, called 

residual P, includes P associated with organic matter. Loosely bound P and P associated with poorly 

crystalline Fe oxides are readily added to water associated with sediment solid particles.

Task 2 – Determine the geospatial distribution of explanatory indicators in 1-cm intervals of the 

upper 5 cm and 5-cm intervals to a depth of 30 cm of UKL bed-sediment cores. With data for the 

concentrations of metals and C with which P is known to bond, mechanisms for P retention and release 

can be formulated.

Purpose and Scope

This report describes the methods used to characterize water content and particle size in samples 

of lakebed sediment. Methods of chemical analysis also are described. Data are tabulated for each of 

26 sites by particle size for depth intervals to 30 cm. This report provides information about where and 

how much P is stored in UKL sediments. The data will help identify locations where remediation might 

be a management option. In addition, this report provides auxiliary chemical information to assist in 

examining models of processes that result in the release or retention of P in UKL sediments.

Study Design and Methods

Sampling Locations

Upper Klamath Lake has a surface area of approximately 259 square kilometers (km2). To obtain 

a representative set of samples for UKL as a whole, a 10.3-km2

 grid was superimposed on a map of the 

lake and sampling sites were selected at random with each unit of the grid. The grid indicated that 26 

cores would be required to provide representative samples for the whole lake.

Sample Collection

One core, approximately 30 cm in length, was collected in October 2006 at each of 26 sites. A 

map showing the 26 sites that were sampled between 24 October and 26 October, 2006, is presented in 

figure 2. Table 3 lists the names and location (latitude and longitude) for each of the sites. The cores 

were collected using a gravity corer containing a plastic butyrate core liner (6.75 cm). The plastic core 

liner was removed from the core barrel while the coring assembly was in a vertical position. Cores were 

sectioned on the boat dock. 

Sediment cores were sectioned at 1-cm intervals from the zone of the core closest to the interface 

between the sediment and the water column to a depth of 5 cm. Samples of sediment between depths of 

10 cm and 30 cm were collected by removing 2-cm sections at 5-cm intervals. For example, the 10-cm 

sample was the material between 9 cm and 11 cm on the tape measuring the length of the core. The 

central portion of each section was transferred to glass screw-cap jars, placed on ice, and shipped 

overnight to the lab in Reston, Virginia (Va.), where they were frozen. 

Sample Preparation

Samples were weighed before and after freeze drying to determine water content.
5

Sediment samples were freeze-dried because the most labile form of P, exchangeable P, was 

shown by Andrieux-Loyer and Aminot (1996) to be stable during the freeze-drying process. In 

preparation of sediment samples, dry sieving is considered preferable to wet sieving to prevent leaching 

of exchangeable P by sieving water (Andrieux-Loyer and Aminot, 1996). Each sample of freeze-dried 

sediment was gently broken up and placed in a 260-mesh (61-μm particle-size) sieve. The sieve was 

agitated, and the fine particles that passed through the screen were collected until the weight of particles 

passing through the sieve after one-half hour of shaking weighed no more than 10 mg. Material 

remaining in the sieve was returned to the mortar and pestle and ground until all of the remaining 

sample passed through a 60-mesh (230-μm particle-size) screen. 

Sample Analysis

Analytical reporting limits, determined for factors measured in this study, are based on the 

detection limits for the analytical methods (table 4). Quality assurance was addressed in the traditional 

manner through analyses of sample duplicates and standard reference samples. Standard reference 

material LKSD–1 was included with each set of microwave digestion samples. 

Sediment pH

When the weights of the wet sediment were measured prior to freezing, an aliquot of 1 to 2 cubic 

centimeters (cm3

) of sediment was transferred to a disposable centrifuge tube. The pH of the wet 

sediment was measured using an Orion Ross electrode and an Orion Model 525A pH meter. The meter 

was recalibrated after completion of each subset of 10 samples. 

Microwave-Assisted Digestion of Sediment Samples

Samples weighing 0.07 to 0.1 g were digested in concentrated nitric and hydrofluoric acids using 

microwave digestion equipment (Simon and others, 2009). An acid blank and reference standard 

LKSD–1 (Lynch, 1990) were included with every set of digest sediments. Ten milliliters (mL) of 

concentrated nitric acid were added approximately 16 hours before 2 mL of hydrofluoric acid were 

added to the Teflon vessels containing the weighed sediment samples. Soaking the samples in nitric acid 

helped wet the samples. The penetration of sediment particles with acid contributes to efficient 

dissolution of sediment particles. Immediately after addition of hydrofluoric acid, the vessels were 

closed, put in the instrument round table, and placed in a CEM Microwave Accelerated Reaction 

System (MARS). After the digestion sequence in the microwave, the samples were brought up to a 

volume of 100 mL using double deionized water. 

A statistical comparison using Welch’s t-test indicated that there is no statistical difference 

between the concentrations of the subject elements determined for LKSD–1 as analyzed in the Reston 

lab and concentrations of the subject elements as reported by the Canadian Certified Reference 

Materials Project (CCRMP) (Lynch, 1990). Data from a set of microwave digestion samples were 

considered acceptable if the concentrations of elements determined in the LKSD–1 standard run with 

the samples were within two standard deviations of the concentration reported in Lynch (1990). Welch’s 

t-test was used because the two sets of data being compared possibly have unequal variances. In 

Welch’s t-test, the denominator is based on a pooled variance estimate. 

Total Phosphorus

The diluted aliquots of microwave digests of sediment samples were analyzed for P 

concentrations using the method of Murphy and Riley (1962). 
6

Sequential Extraction

Although originally developed for use with marine sediments, the Ruttenberg (1992) method 

(also known as the SEDEX method) has been used for sequential extraction of P from freshwater 

sediments (Ruban and others, 1999; Brunberg and others, 2002; Filippelli and others, 2006) and from 

freshwater and estuarine sediments (Andrieux-Loyer and others, 2008). In this method, P is fractionated 

into loosely sorbed P and interstitial water P using MgCl2 (1 M, pH 8); easily reducible Fe-bound P 

using citrate-dithionite-bicarbonate (CDB) solution (pH 7.6); and P associated with carbonates and acidsoluble minerals using 1 N hydrochloric acid (HCl) (fig. 2). The concentrations of loosely sorbed P and 

P associated with poorly crystalline Fe-oxyhydroxides are operationally defined as bioavailable P 

(Ruban and others, 1999). 

Sediment samples weighing approximately 0.1 g were extracted using the SEDEX method 

(Ruttenberg, 1992) with the modifications of Anderson and Delaney (2000). The sodium acetate step 

was omitted, and the extraction time for the CDB extraction was increased to facilitate the dissolution of 

poorly crystalline Fe-oxyhydroxides. Dissolved reactive P (DRP) concentrations in all fractions were 

determined by the molybdenum blue method (Murphy and Riley, 1962). Butanol extraction of samples 

was not required for colorimetric P analysis of CDB extracts because concentrations of P in the CDB 

extracts were within detection limits of the colorimetric method, and dithionite solutions were heated in 

air to remove interference from sulfide ion. Residual P concentrations were calculated by subtracting the 

sum of the concentrations of P recovered in the sequential extraction procedure (inorganic P) from the 

concentrations of total P. Concentrations of Fe were determined in CDB fractions using a Perkin-Elmer 

Model 5100 ICP–AES.

Carbon and Nitrogen Concentrations

Sediments were analyzed for total C and total N using 20 mg of freeze-dried, ground samples. 

Flash oxidation of each sample was followed by separation of the gaseous products using a Carlo Erba 

EA 1108 Elemental Analyzer. Two aliquots of sediment samples from the Mid Lake (ML) site were 

analyzed: one aliquot was analyzed without treatment with HCl to determine the total C concentration, 

and a second aliquot was treated with HCl vapors to remove carbonates before analysis to determine the 

concentration of organic C. This experiment was done to test the statement in Bradbury and others 

(2004) that UKL sediments are carbonate free. We analyzed sediment from the ML site where 

concentrations of Ca in the sediment were determined to be greater than in sediment from other sites 

sampled in this study. The similarity in C concentrations before and after HCl treatment indicated that 

total C was organic C, with no detectable carbonates present (data not shown). 

Metals Analysis (Aluminum, Calcium, Iron, and Titanium)

Microwave digests were diluted 1:20 with 0.5 percent nitric acid and analyzed for Al, Ca, Fe, 

and Ti using a Perkin-Elmer Model 5100 ICP–AES.

Physical and Chemical Characteristics of Lakebed Sediment

Data from the 26 cores presented in this report give a geospatial distribution of sediment particle 

size, total P, loosely bound P, P associated with poorly crystalline Fe oxides; mineral forms of P, Fe, 

and Fe in poorly crystalline Fe oxides; and Al, C, Ca, N, and Ti (table 2). 
7

Water Content and Particle Size

The percentage of water in sediment samples is inversely related to the percentage of particles.

The percentage of water in whole sediment samples is small at sites 9, 21, and 23. At these sites, the 

concentrations of chemical constituents in sediment solids have more of an effect on the amount of 

chemical constituent in the sediment than at sites where the percentage of water is larger.

Examination by microscope of the sediment indicates that large numbers of diatom frustules are 

present. These silicon structures act as a diluent in the calculation of the concentrations of chemical 

constituents in these sediment samples. Visual examination of sediments indicates that the fine fraction 

(<63 μm) contains fewer aggregates of diatom frustules than the coarse fraction (>63 μm) of sediment.

In general, the fraction of coarse particles is larger in sediment from sites in the northern portion of the 

lake than in the southern portion of the lake. 

Distribution of Phosphorus, Geochemical Fractions of Phosphorus and Chemical Constituents 

Concentrations of total Al, Fe, P, and Ti calculated as milligrams per gram (mg g-1) dry weight 

sediment are largest in cores from sites located in the northern portion of the lake as well in cores from 

sites in Howard Bay and the southernmost portion of the lake. 

Concentrations of total P were largest in the top 1 cm of sediment. This surface sediment is at 

the sediment water interface and is the contact between bottom sediment and overlying water column.

The concentrations of total P in the top 1 cm of sediment at sites 23, 25, and 26 (sites along the northern 

rim of UKL) are larger than 0.6 mg g-1 dry weight. The concentrations of total P in the top 1 cm of 

sediment at sites 7, 18, and 21 are larger than 0.5 mg g-1 dry weight sediment. The concentrations in the 

top 1 cm of sediment at all other sample sites in this study were less than 0.5 mg g-1 dry weight. 

In UKL surface sediment, the correlation between concentrations of total P and total Fe is poor 

(R2<0.1). In the case of simple linear regression, R2 is the square of the sample correlation coefficient

between the outcomes and the values being used for prediction. There is a good correlation between 

concentrations of total P concentrations of dithionite-extractable Fe (poorly crystalline Fe oxides) for all 

samples collected for this study. The R2 for the linear relationship is 0.4, and the R2 for a second degree 

polynomial is 0.6, with total P concentrations increasing rapidly with increased concentrations of 

dithionite-extractable Fe.

The R2

 for the linear regression for the concentrations of total Fe and total Ti is greater than 0.9 

for both coarse and fine fractions of the sediment samples. This indicates that Fe and Ti might have a 

similar (probably terrestrial) source. The largest concentrations of Ti in bottom sediment are at sites 8, 

9, 17, 21, and 23, indicating that sediment accumulating at these sites has a terrestrial source.

Summary 

Concentrations of chemical constituents in the sediments collected for this study are affected by 

large numbers of diatom frustules in the sediment. The frustules have a diluent effect. This survey of 

surface sediment in UKL provides data that indicates that concentrations of total P, geochemical 

fractions of P, and chemical constituents in sediments of UKL are not uniformly distributed. The 

distribution of the total P indicates larger concentrations calculated both on a dry weight basis and on a 

wet weight basis (whole sediment) are present in sediment cores collected from the northern portion of 

the lake. The largest fraction of P in the sediment cores was residual P. One of the components in the 

residual fraction is organic P.
8

The concentrations of organic C in the coarse fraction are larger than the concentrations of 

organic C in the fine fraction of these sediment samples. Concentrations of C and N in sediment samples 

have patterns that differ from P concentrations in sediment samples. The largest concentrations of C and 

N occur in sediment in the southern portion, as well as the northern portion, of the lake. The largest 

concentrations of Ti, a metal associated with terrestrial material, were determined in sediment in the 

northeastern portion and the central part of the lake. The distribution of the total concentration of the 

metals Al, Ca, and Fe, was similar to the distribution of the concentrations of Ti.

References Cited

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sediments: Streamlining of the SEDEX procedure: Limnology and Oceanography, v. 45, p. 509–515, 

accessed March 22, 2010, at http://www.jstor.org/stable/2670508. 

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sediments: Water Research, v. 30, no. 11, p. 2805–2811 (also available 

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Andrieux-Loyer, F., Philippon, X., Bally, G., Kérouel, R.,Youenou, A., and Le Grand, J., 2008, 

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188 (also available at http://dx.doi.org/10.1023/B:JOPL.0000019232.74649.02). 

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lakes as revealed by sediment P-fractionation: Archiv für Hydrobiologie, v. 153, p. 491–502.

Dileanis, P.D., Schwarzbach, S.E., and Bennett, J., 1996, Detailed study of water quality, bottom 

sediment, and biota associated with irrigation drainage in the Klamath Basin, California and Oregon, 

1990–92: U.S. Geological Survey Water-Resources Investigations Report 95–4232, 68 p. (Also 

available at http://pubs.er.usgs.gov/djvu/WRI/wrir_95_4232.djvu).

Eilers, J., Kann, J., Cornett, J., Moser, K., St. Amand, A., and Gubala, C., 2001, Recent paleolimnology

of Upper Klamath Lake, Oregon: Prepared for U.S. Bureau of Reclamation, Klamath Falls, Oregon by 

J.C. Headwaters, Inc., Roseburg, Oregon, 44 p. (also available 

at http://klamathwaterlib.oit.edu/u?/kwl,641). 

Filippelli, G. M., Souch, C., Menounos, B., Slater-Atwater, S., Jull, A.J.T., and Slaymaker, O., 2006, 

Alpine lake sediment records of the impact of glaciation and climate change on the biogeochemical 

cycling of soil nutrients: Quaternary Research, v. 66, p. 158–166 (also available 

at http://dx.doi.org/10.1016/j.yqres.2006.03.009). 

Fisher, L.H., and Wood, T.M., 2004, Effect of water-column pH on sediment-phosphorus release rates 

in Upper Klamath Lake, Oregon, 2001: U.S. Geological Survey Water-Resources Investigations 

Report 03–4271, 25 p. (Also available at http://pubs.usgs.gov/wri/wri034271/). 

Klamath Consulting Service, Inc., 1983, EPA 314 clean lakes program 1981–1983: Phase 1: 

Diagnostic/Feasibility Study: Klamath County, Oregon, Klamath Falls, Oregon, 151 p. plus 

Appendix, accessed March 22, 2010, at http://klamathwaterlib.oit.edu/u?/kwl,1987. 

Kleeberg, A., and Kozerski, H.-P, 1997, Phosphorus release in Lake Großer Müggelsee and its 

implications for lake restoration: Hydrobiologia, v. 342/323, p. 9–26, accessed March 22, 2010, 

at http://www.springerlink.com/content/rk17gxm6h6v27225/fulltext.pdf. 
9

Lynch, J., 1990, Provisional Elemental Values for Eight New Geochemical Lake Sediment and Stream 

Sediment Reference Materials, LKSD–1, LKSD–2, LKSD–3, LKSD–4, STSD–1, STSD–2, STSD–3 

and STSD–4: Geostandards Newsletter, v. 14, no. 1, p. 153–167, accessed March 22, 2010, 

at http://www.crpg.cnrs-nancy.fr/Geostandards/GGR_volindex.html. 

Marsden, M.W., 1989, Lake restoration by reducing external phosphorus loading: the influence of 

sediment phosphorus release: Freshwater Biology, v. 21, p. 139–162 (also available 

at http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2427.1989.tb01355.x/pdf). 

Murphy, J., and Riley, J.P., 1962, A modified single solution method for the determination of phosphate 

in natural waters: Analytical Chemical Act, v. 27, p. 31–36 (also available at 

http://dx.doi.org/10.1016/S0003-2670(00)88444-5). 

National Research Council, Committee on endangered and threatened fishes in the Klamath River 

Basin, 2004, Executive summary: Endangered and threatened fishes in the Klamath River Basin: 

Causes of decline and strategies for recovery: The National Academies, Washington, D.C.: National 

Academies Press, 385 p., accessed November 6, 2009, 

at http://www.nap.edu/openbook.php?record_id=10838. 

Oregon Department of Environmental Quality, 2002, Upper Klamath Lake Drainage Total Maximum 

Daily Load (TMDL) and Water Quality Management Plan (WQMP): State of Oregon Department of 

Environmental Quality, p. 586, accessed March 22, 2010, 

at http://www.fs.fed.us/r6/frewin/projects/waterqual/UprKlamathTMDL.pdf.

Phillips, G., Kelly, A., Pitt, J.A., Sanderson, R. and Taylor, E., 2005, The recovery of a very shallow 

eutrophic lake, 20 years after the control of effluent derived phosphorus: Freshwater Biology, v. 50, p. 

1628–1638 (also available at http://dx.doi.org/10.1111/j.1365-2427.2005.01434.x). 

Ruban, V. J., López-Sánchez, F., Pardo, P., Rauret, G., Muntau, H., and Quevauviller, P., 1999, 

Selection and evaluation of sequential extraction procedures for the determination of phosphorus 

forms in lake sediment: Journal of Environmental Monitoring, v. 1, p. 51–56 (also available 

at http://dx.doi.org/10.1039/a807778i). 

Ruttenberg, K.C., 1992, Development of a sequential extraction method for different forms of 

phosphorus in marine sediments: Limnology and Oceanography, v. 37, p. 1460–1482, accessed March 

22, 2010, at http://www.jstor.org/stable/2837963. 

Sanville, W.D., Powers, C.F., and Gahler, A.R., 1974, Sediments and sediment-water nutrient 

interchange in Upper Klamath Lake, Oregon, EPA–660/3–74–015, National Environmental Research 

Center, Office of Research and Development: U.S. Environmental protection Agency, Corvallis, 

Oregon, v. 97330, 45 p., accessed May 18, 2011, 

at http://dspace.udel.edu:8080/dspace/handle/19716/1378. 

Simon, N.S., Lynch, D., and Gallaher, T.N., 2009, Phosphorus fractionation in sediment cores collected 

in 2005 before and after onset of an Aphanizomenon flos-aquae bloom in Upper Klamath Lake, OR, 

USA: Water, Air and Soil Pollution, v. 204, nos. 1–4, p. 139–153, accessed March 22, 2010, 

at http://springerlink.com/content/06580113p6q415v7/fulltext.pdf. 

Wildung, R.E., Schmidt, R.L. and Routson, R.C., 1977, The phosphorus status of eutrophic lake 

sediments as related to changes in limnological conditions—phosphorus mineral components: Journal 

of Environmental Quality, v. 16, p. 100–104, also available

at http://dx.doi.org/10.2134/jeq1977.00472425000600010022x. 

Wood, T.M., Cheng, R.T., Gartner, J.W., Hoilman, G.R., Lindenberg, M.K., and Wellman, R.E., 2008, 

Modeling hydrodynamics and heat transport in Upper Klamath Lake, Oregon, and implications for 

water quality: U.S. Geological Survey Scientific Investigations Report 2008–5076, p. 48. (Also 

available at http://pubs.usgs.gov/sir/2008/5076/). 
10

Acknowledgments

We greatly appreciate the excellent work of the field crew from the USGS office in Klamath 

Falls, Oregon (Oreg.). They collected the cores analyzed in this study, and provided the photograph that 

appears on the cover of this report. The photo shows coring operations during the October 2006 

collection of sediment cores from Upper Klamath Lake, Oregon. 
11

Figure 1. Map showing location of Upper Klamath Lake, Oregon, and sampling sites. 
12

Figure 2. Flow chart of sequential extraction procedure used to separate inorganic phosphorus (P) from 

sediment samples collected in October 2006 from Upper Klamath Lake, Oregon. 
13

Table 1. Comparison of concentrations of total and inorganic phosphorus (P) in sediment from cores collected October 2006 from Upper Klamath Lake, 

Oregon, with other data from reports in the literature.

[DW, dry weight; H3BO3, boric acid ; HCl, hydrochloric acid; HF, hydrofluoric acid; HNO3, nitric acid; mg g-1, milligrams per gram; Na2CO3, sodium 

carbonate] 

Location in Upper 

Klamath Lake

Study site 

nearest to site 

in published 

study

Year of sample 

collection Authors of study Method of analysis for total phosphorus

Concentration of total 

phosphorus mg g-1

DW: average of 

sediment, 1–10 cm

Concentration of 

inorganic phosphorus , 

mg g-1 DW: average of 

sediment, 1–10 cm

Lake outlet Site 1 1968–1969 Sanville and others 

(1974)

Not reported 0.40±0.86

Pelican Marina Site 1 1969 and 1970 Wildung and others 

(1977)

Na2CO3 fusion

0.66±0.018 0.35

Buck Island Site 2 1968–1969 Sanville and others 

(1974)

Not reported 0.26±0.65

Buck Island Site 2 1969 and 1970 Wildung and others 

(1977)

Na2CO3 fusion

1.03±0.03 0.30±0.03

Howard Bay Site 3 1968–1969 Sanville and others 

(1974)

Not reported 0.58±1.16

Howard Bay Site 3 1969 and 1970 Wildung and others 

(1977)

Na2CO3 fusion

1.03±0.05 0.57±0.05

Howard Bay Site 3 2005 Simon and others 

(2009)

Microwave digestion, 

HNO3 + HF

0.63±0.10 April 0.16±0.05 April

0.46±0.14 July 0.14±0.07 July

Mid Lake Site 9 2005 Simon and others 

(2009)

Microwave digestion, 

HNO3 + HF

0.37±0.11 April 0.09±0.02 April

0.46±0.14 July 0.08±0.05 July

Bare Island Site 16 2005 Simon and others 

(2009)

Microwave digestion, 

HNO3 + HF

0.66±0.15 April 0.21±0.17 April

0.62±0.07 July 0.12±0.13 July

Mouth of 

Shoalwater Bay

Site 19 1998 Eilers and others (2001) Microwave digestion, 

HNO3 + HF + HCl + 

H3BO3

0.9

Ball Bay Site 14 2005 Simon and others 

(2005)

Microwave digestion, 

HNO3 + HF

0.81±0.10 April 0.23±0.12 April

0.85±0.11 July 0.13±0.08 July
14

Table 2. Analytical data for sediment cores collected October 24–26, 2006, from Upper Klamath Lake, Oregon

[Al, aluminum; Ca, calcium; DW, dry weight; Fe, iron; HCl, hydrochloric acid; m, meter; mg g-1, milligram per gram; NA, not available; P, phosphorus; Ti, titanium]

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 1: North of the city of Klamath Falls

-0.5 > 63 μm 0.52 0.48 0.04 0.20 0.05 0.19 7.04 0.93 29.55 1.59 48.00 12.15 2.78

-1.5 0.80 0.35 0.03 0.20 0.05 0.06 6.64 0.85 28.20 1.39 46.71 12.19 2.64

-2.5 0.58 0.48 0.03 0.20 0.04 ND 6.69 0.86 13.28 1.27 22.39 6.96 1.29

-3.5 0.69 0.40 0.02 0.16 0.05 0.17 6.20 0.83 29.84 1.11 48.65 13.14 2.78

-4.5 0.59 0.40 0.01 0.14 0.04 0.21 6.43 0.84 30.31 1.22 50.74 13.63 2.85

-0.5 < 63 μm 0.48 0.50 0.05 0.19 0.05 0.21 6.41 0.82 27.02 1.65 41.30 11.13 2.46

-1.5 0.20 0.33 0.04 0.15 0.06 0.08 6.28 0.76 27.23 1.41 45.24 11.95 2.64

-2.5 0.43 0.32 0.02 0.13 0.06 0.24 5.94 0.77 25.51 1.01 37.36 10.62 2.49

-3.5 0.31 0.32 0.02 0.12 0.04 0.20 5.60 0.69 25.47 1.07 38.06 10.16 2.50

-4.5 0.42 0.34 0.01 0.11 0.04 0.19 5.55 0.71 26.66 1.01 36.68 9.88 2.54

1.8 0.92 6.67 -0.5 All particles 0.49 0.05 0.19 0.05 0.20 6.74 0.88 28.34 1.62 44.80 11.66 2.62

1.8 0.91 6.18 -1.5 0.34 0.03 0.19 0.05 0.07 6.57 0.83 28.01 1.40 46.42 12.15 2.64

1.8 0.90 6.05 -2.5 0.42 0.03 0.17 0.05 0.09 6.46 0.83 18.76 1.18 29.19 8.64 1.83

1.8 0.90 6.33 -3.5 0.37 0.02 0.15 0.05 0.18 6.04 0.79 28.57 1.10 45.50 12.25 2.70

1.8 0.90 6.19 -4.5 0.38 0.01 0.12 0.04 0.21 6.14 0.80 29.19 1.15 45.48 12.23 2.76

-10 > 63 μm 0.46 0.29 0.01 0.08 0.05 0.15 5.04 0.67 31.95 1.45 73.49 22.52 2.99

-15 0.47 0.29 0.01 0.06 0.04 0.10 4.05 0.56 23.50 0.74 46.00 13.62 2.47

-20 0.34 0.29 0.01 0.06 0.05 0.10 5.03 0.67 33.36 1.08 56.65 11.99 3.05

-25 0.31 0.29 0.01 0.04 0.05 0.09 4.89 0.65 33.18 0.87 66.08 15.29 3.31

-30 0.37 0.29 0.01 0.03 0.06 0.04 4.60 0.61 31.67 0.90 62.55 13.88 3.27

-10 < 63 μm 0.54 0.14 0.01 0.05 0.04 0.13 4.06 0.56 22.10 1.28 32.07 7.81 2.00

-15 0.53 0.19 0.01 0.04 0.03 0.11 3.94 0.59 20.30 0.77 31.66 7.32 1.94

-20 0.66 0.14 0.00 0.03 0.04 0.11 3.85 0.56 30.73 1.06 34.86 7.05 2.32

-25 0.69 0.16 0.01 0.02 0.04 0.08 3.59 0.53 25.48 0.76 32.30 6.93 2.18

-30 0.63 0.18 0.01 0.02 0.05 0.10 3.39 0.47 25.99 0.79 34.26 7.77 2.32

1.8 4.90 -10 All particles 0.21 0.01 0.06 0.05 0.14 4.52 0.61 26.64 1.36 51.16 14.59 2.46

1.8 5.57 -15 0.24 0.01 0.05 0.04 0.10 3.99 0.57 21.81 0.76 38.43 10.29 2.19

1.8 5.52 -20 0.19 0.01 0.04 0.04 0.11 4.25 0.60 31.62 1.07 42.20 8.71 2.56

1.8 5.65 -25 0.20 0.01 0.03 0.04 0.09 4.00 0.57 27.87 0.80 42.82 9.53 2.53

1.8 6.02 -30 0.22 0.01 0.03 0.05 0.08 3.84 0.52 28.10 0.83 44.76 10.03 2.67
15

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 2: Buck Island

-0.5 > 63 μm 0.80 0.58 0.04 0.11 0.04 0.39 7.53 0.96 27.37 1.93 36.65 9.96 2.55

-1.5 0.93 0.46 0.03 0.09 0.05 0.30 7.06 0.90 27.10 1.53 40.27 10.17 2.60

-2.5 0.52 0.48 0.02 0.05 0.05 0.37 7.38 0.94 28.12 1.50 37.52 10.50 2.76

-3.5 0.86 0.40 0.01 0.04 0.04 0.32 6.65 0.83 27.60 1.28 42.19 10.24 2.64

-4.5 0.64 0.38 0.01 0.03 0.04 0.29 6.73 0.88 29.33 1.15 38.86 10.91 2.79

-0.5 < 63 μm 0.20 0.59 0.04 0.07 0.05 0.43 6.71 0.83 28.98 2.10 43.08 13.08 2.73

-1.5 0.06 NA 0.03 0.06 0.06 NA 6.28 0.76 NA 1.61 NA NA NA

-2.5 0.50 0.40 0.01 0.06 0.05 0.28 5.94 0.78 27.16 1.26 40.55 10.73 2.59

-3.5 0.13 0.40 0.01 0.03 0.05 0.31 4.80 0.66 26.26 1.14 46.15 13.16 2.59

-4.5 0.37 0.44 0.02 0.03 0.04 0.36 5.93 0.78 27.44 1.22 39.00 10.79 2.57

1.8 0.89 6.36 -4.5 All particles 0.58 0.04 0.10 0.04 0.40 7.37 0.94 27.68 1.96 37.91 10.57 2.58

1.8 0.90 6.46 -3.5 0.43 0.03 0.08 0.05 0.28 6.95 0.88 25.22 1.52 37.47 9.47 2.42

1.8 0.91 6.41 -2.5 0.45 0.02 0.05 0.05 0.33 6.82 0.88 28.21 1.41 39.79 10.83 2.73

1.8 0.92 6.42 -1.5 0.40 0.01 0.04 0.04 0.31 6.36 0.81 27.22 1.26 42.40 10.54 2.61

1.8 0.93 6.50 -0.5 0.40 0.01 0.03 0.04 0.31 6.46 0.84 28.73 1.18 39.03 10.90 2.72

-10 > 63 μm 0.66 0.37 0.01 0.05 0.04 0.27 6.40 0.84 28.73 1.08 38.70 9.91 2.53

-15 0.67 0.23 0.02 0.02 0.03 0.17 5.12 0.72 22.08 0.90 38.33 9.85 2.11

-20 0.53 0.26 0.01 0.03 0.03 0.19 4.81 0.66 21.84 0.70 34.03 8.29 1.99

-25 0.39 0.27 0.01 0.03 0.04 0.19 5.64 0.75 22.11 0.72 34.43 8.51 2.28

-30 0.51 0.18 0.01 0.01 0.03 0.12 5.10 0.73 18.87 0.45 30.55 7.06 1.89

-10 < 63 μm 0.34 0.35 0.01 0.03 0.06 0.24 4.49 0.60 24.05 1.00 38.83 10.50 2.30

-15 0.33 0.15 0.01 0.02 0.04 0.08 3.92 0.56 19.07 0.73 37.33 11.54 1.84

-20 0.47 0.14 0.01 0.02 0.04 0.07 3.79 0.53 20.55 0.65 33.75 10.25 1.86

-25 0.61 0.21 0.01 0.03 0.03 0.15 3.25 0.46 16.01 0.52 27.66 6.16 1.42

-30 0.49 0.15 0.02 0.02 0.04 0.09 3.85 0.55 17.41 0.39 30.29 7.02 1.64

1.8 6.66 -10 All particles 0.36 0.01 0.04 0.05 0.26 5.74 0.76 27.12 1.06 38.74 10.11 2.45

1.8 6.14 -15 0.21 0.02 0.02 0.04 0.14 4.73 0.67 21.08 0.84 38.00 10.41 2.02

1.8 6.50 -20 0.20 0.01 0.02 0.03 0.13 4.33 0.60 21.23 0.67 33.90 9.21 1.93

1.8 6.66 -25 0.23 0.01 0.03 0.03 0.17 4.18 0.57 18.37 0.59 30.28 7.07 1.75

1.8 7.10 -30 0.17 0.01 0.01 0.03 0.10 4.49 0.64 18.15 0.42 30.42 7.04 1.77
16

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 3: Howard Bay (Wocus Bay)

-0.5 > 63 μm 0.66 0.59 0.03 0.11 0.05 0.40 8.39 1.04 27.55 1.07 37.29 9.84 2.47

-1.5 0.75 0.51 0.02 0.10 0.05 0.33 7.76 0.97 28.18 0.92 38.21 9.73 2.49

-2.5 0.61 0.35 0.02 0.09 0.05 0.20 7.47 0.92 28.04 0.92 40.45 10.53 2.49

-3.5 0.81 0.36 0.02 0.10 0.05 0.20 7.04 0.79 28.85 0.73 37.92 10.11 2.53

-4.5 0.53 0.29 0.01 0.08 0.05 0.15 7.11 0.82 29.68 0.61 41.75 10.72 2.64

-0.5 < 63 μm 0.34 0.55 0.02 0.10 0.06 0.37 7.17 0.75 26.73 0.95 41.11 11.44 2.40

-1.5 0.20 0.53 0.02 0.10 0.05 0.36 6.28 0.64 25.55 0.99 39.90 11.49 2.35

-2.5 0.40 0.52 0.03 0.08 0.05 0.36 6.44 0.70 27.16 1.27 37.55 10.56 2.40

-3.5 0.17 0.42 0.02 0.07 0.06 0.28 6.22 0.77 26.43 0.66 37.55 11.94 2.55

-4.5 0.50 0.48 0.01 0.09 0.06 0.32 6.43 0.79 26.90 0.80 31.71 9.65 2.37

0.6 0.95 6.34 -0.5 All particles 0.58 0.03 0.11 0.06 0.39 7.97 0.94 27.27 1.03 38.60 10.39 2.44

0.6 0.94 5.95 -1.5 0.49 0.02 0.10 0.05 0.32 7.08 0.86 26.29 0.89 36.70 9.61 2.34

0.6 0.93 6.36 -2.5 0.42 0.02 0.08 0.05 0.27 7.18 0.85 28.16 1.08 39.96 10.72 2.50

0.6 0.93 6.54 -3.5 0.37 0.02 0.09 0.05 0.21 6.81 0.78 28.07 0.71 37.39 10.30 2.50

0.6 0.92 6.14 -4.5 0.40 0.01 0.09 0.06 0.24 7.00 0.83 29.25 0.72 38.07 10.54 2.59

-10 > 63 μm 0.53 0.27 0.01 0.01 0.05 0.20 6.99 0.96 31.18 0.51 38.77 9.99 2.54

-15 0.59 0.27 0.01 0.06 0.04 0.17 6.99 1.00 30.51 0.49 36.25 9.06 2.45

-20 0.61 0.25 0.00 0.06 0.03 0.16 6.74 0.99 26.33 0.45 37.01 8.52 2.14

-25 0.57 0.11 0.00 0.05 0.03 0.03 6.74 0.99 21.77 0.57 32.45 7.71 1.99

-30 0.56 0.08 0.00 0.01 0.03 0.05 6.39 0.90 21.76 0.54 32.66 7.80 2.03

-10 < 63 μm 0.47 0.36 0.01 0.06 0.05 0.25 5.28 0.69 26.30 0.42 35.60 10.24 2.38

-15 0.41 0.32 0.00 0.06 0.05 0.21 4.83 0.65 25.56 0.44 35.80 10.01 2.27

-20 0.39 0.19 0.00 0.07 0.04 0.08 4.47 0.64 22.51 0.39 35.00 9.12 1.97

-25 0.43 0.29 0.00 0.08 0.03 0.18 3.99 0.59 17.65 0.42 31.49 8.10 1.62

-30 0.44 0.28 0.00 0.04 0.03 0.22 3.97 0.59 17.48 0.36 32.40 8.38 1.63

0.6 6.20 -10 All particles 0.32 0.01 0.03 0.05 0.22 6.18 0.83 28.86 0.47 37.27 10.11 2.46

0.6 6.46 -15 0.29 0.01 0.06 0.05 0.18 6.10 0.86 28.48 0.47 36.07 9.45 2.37

0.6 6.47 -20 0.23 0.00 0.06 0.04 0.13 5.84 0.85 24.82 0.43 36.22 8.75 2.07

0.6 5.59 -25 0.19 0.00 0.06 0.03 0.09 5.57 0.82 20.01 0.51 32.04 7.88 1.83

0.6 5.58 -30 0.17 0.00 0.02 0.03 0.12 5.32 0.76 19.88 0.46 32.54 8.06 1.86
17

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 4: Mouth of Howard Bay, South

-0.5 > 63 μm 0.78 0.35 0.01 0.09 0.07 0.18 6.42 0.77 15.14 0.99 36.19 9.13 1.47

-1.5 0.81 0.35 0.00 0.08 0.06 0.20 6.51 0.77 14.32 0.98 29.22 7.96 1.37

-2.5 0.77 0.33 0.01 0.02 0.06 0.25 6.57 0.78 14.59 0.94 28.37 7.13 1.33

-3.5 0.84 0.37 0.00 0.07 0.06 0.24 6.71 0.80 14.64 0.92 27.88 6.85 1.30

-4.5 0.82 0.36 0.00 0.07 0.05 0.23 6.80 0.83 14.99 0.88 29.98 7.91 1.34

-0.5 < 63 μm 0.21 0.27 0.01 0.07 0.09 0.10 5.22 0.59 13.44 0.78 34.72 10.38 1.49

-1.5 0.19 0.41 0.00 0.04 0.08 0.29 5.67 0.63 14.03 0.69 26.25 6.07 1.40

-2.5 0.22 0.35 0.00 0.02 0.07 0.26 5.47 0.60 12.74 0.78 19.86 9.81 1.36

-3.5 0.16 0.34 0.01 0.04 0.08 0.22 5.13 0.55 13.37 0.48 20.59 11.44 1.33

-4.5 0.17 0.22 0.01 0.06 0.07 0.08 5.03 0.55 13.00 0.72 31.25 9.60 1.37

1.7 0.91 6.26 -0.5 All particles 0.33 0.01 0.08 0.08 0.16 6.08 0.72 14.56 0.93 35.35 9.26 1.45

1.7 0.90 5.60 -1.5 0.36 0.00 0.07 0.06 0.22 6.35 0.74 14.27 0.92 28.64 7.59 1.37

1.7 0.90 5.92 -2.5 0.34 0.00 0.02 0.06 0.25 6.29 0.74 14.10 0.90 26.31 7.69 1.33

1.7 0.90 5.98 -3.5 0.37 0.00 0.06 0.06 0.24 6.45 0.76 14.42 0.85 26.68 7.58 1.31

1.7 0.90 6.01 -4.5 0.34 0.00 0.07 0.06 0.21 6.43 0.77 14.50 0.84 29.89 8.11 1.33

-10 > 63 μm 0.58 0.37 0.01 0.06 0.04 0.26 6.41 1.12 9.29 2.11 15.63 3.58 0.90

-15 0.51 0.48 0.02 0.09 0.04 0.33 6.72 0.97 9.38 1.04 14.32 3.61 0.92

-20 0.53 0.48 0.03 0.08 0.05 0.32 6.77 1.00 9.32 0.86 15.01 3.68 0.95

-25 0.59 0.44 0.03 0.11 0.05 0.26 6.40 0.95 9.58 0.84 14.29 4.43 0.93

-30 0.56 0.42 0.04 0.13 0.04 0.21 5.62 0.82 9.28 0.71 13.99 4.28 0.87

-10 < 63 μm 0.42 0.39 0.01 0.07 0.05 0.26 5.20 0.75 9.02 0.86 18.72 4.59 0.95

-15 0.49 0.40 0.02 0.09 0.05 0.25 5.18 0.75 8.60 0.86 16.64 4.31 0.90

-20 0.47 0.38 0.02 0.07 0.04 0.24 5.18 0.77 8.13 0.72 16.21 4.03 0.87

-25 0.41 0.37 0.03 0.09 0.05 0.21 4.66 0.69 7.89 0.62 14.96 3.95 0.82

-30 0.44 0.35 0.04 0.07 0.05 0.19 4.18 0.62 7.96 0.59 12.69 4.05 0.74

1.7 6.36 -10 All particles 0.38 0.01 0.06 0.04 0.26 5.91 0.97 9.18 1.59 16.92 4.00 0.92

1.7 6.85 -15 0.44 0.02 0.09 0.04 0.29 5.97 0.86 8.99 0.95 15.45 3.95 0.91

1.7 7.22 -20 0.43 0.03 0.08 0.04 0.28 6.03 0.89 8.76 0.80 15.57 3.84 0.91

1.7 7.12 -25 0.41 0.03 0.10 0.05 0.24 5.69 0.84 8.88 0.75 14.56 4.23 0.88

1.7 7.73 -30 0.39 0.04 0.11 0.04 0.20 5.00 0.73 8.71 0.66 13.42 4.18 0.82
18

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 5: Rattlesnake Point, South

-0.5 > 63 μm 0.77 0.54 0.01 0.12 0.05 0.36 7.89 0.89 15.92 3.64 23.08 4.83 1.23

-1.5 0.83 0.33 0.01 0.13 0.05 0.14 7.60 0.87 12.06 1.72 17.64 4.09 1.19

-2.5 0.89 0.34 0.01 0.04 0.04 0.26 7.17 0.80 13.50 1.14 22.14 5.04 1.11

-3.5 0.84 0.33 0.00 0.06 0.04 0.23 6.56 0.71 13.35 0.82 21.96 5.08 1.12

-4.5 0.81 0.31 0.00 0.07 0.05 0.19 6.62 0.73 13.41 0.79 20.30 5.60 1.16

-0.5 < 63 μm 0.21 0.48 0.01 0.26 0.06 0.15 6.34 0.67 13.09 1.13 14.12 5.71 1.15

-1.5 0.17 0.26 0.01 0.17 0.00 0.08 6.40 0.70 7.75 1.03 11.35 2.02 1.15

-2.5 0.10 0.41 0.01 0.13 0.06 0.21 5.82 0.61 13.01 0.65 21.89 4.66 1.20

-3.5 0.16 0.24 0.00 0.06 0.06 0.12 5.50 0.58 12.72 0.80 26.38 7.40 1.23

-4.5 0.19 0.19 0.00 0.05 0.05 0.10 5.35 0.57 12.26 0.75 24.66 7.13 1.19

1.0 0.94 5.88 -0.5 All particles 0.51 0.01 0.14 0.05 0.31 7.39 0.82 14.97 3.03 20.67 4.91 1.19

1.0 0.91 6.30 -1.5 0.32 0.01 0.14 0.04 0.13 7.40 0.84 11.34 1.60 16.59 3.75 1.18

1.0 0.92 6.34 -2.5 0.35 0.01 0.05 0.04 0.25 6.99 0.78 13.38 1.09 22.00 4.97 1.11

1.0 0.91 6.47 -3.5 0.32 0.00 0.06 0.04 0.21 6.39 0.69 13.25 0.82 22.65 5.45 1.14

1.0 0.90 6.15 -4.5 0.29 0.00 0.06 0.05 0.17 6.38 0.70 13.20 0.78 21.13 5.89 1.16

-10 > 63 μm 0.66 0.40 0.01 0.06 0.04 0.28 6.36 0.85 13.46 2.10 17.71 4.32 1.13

-15 0.64 0.32 0.01 0.04 0.03 0.24 5.78 0.84 11.53 0.86 16.11 3.94 0.97

-20 0.65 0.26 0.01 0.05 0.03 0.17 5.16 0.75 10.63 0.73 16.85 3.96 0.90

-25 0.57 0.30 0.02 0.04 0.04 0.20 3.70 0.53 10.05 1.10 17.19 4.04 0.96

-30 0.46 0.33 0.02 0.08 0.05 0.18 4.67 0.65 11.84 0.65 22.99 5.42 1.18

-10 < 63 μm 0.34 0.37 0.02 0.06 0.06 0.23 4.55 0.60 10.65 1.22 17.72 4.86 1.04

-15 0.36 0.42 0.01 0.03 0.03 0.34 4.06 0.57 14.86 0.98 15.35 4.56 0.87

-20 0.35 0.35 0.02 0.01 0.04 0.28 4.29 0.59 9.75 0.73 20.97 4.37 0.87

-25 0.43 0.23 0.01 0.01 0.03 0.17 3.64 0.50 10.70 0.39 20.99 4.35 0.96

-30 0.54 0.23 0.02 0.03 0.03 0.15 3.09 0.45 11.24 0.69 19.15 4.19 0.92

1.0 6.16 -10 All particles 0.39 0.01 0.06 0.05 0.27 5.74 0.77 12.50 1.80 17.71 4.50 1.10

1.0 6.33 -15 0.36 0.01 0.04 0.03 0.28 5.16 0.74 12.74 0.91 15.84 4.16 0.93

1.0 7.09 -20 0.29 0.01 0.04 0.03 0.21 4.85 0.69 10.32 0.73 18.30 4.10 0.89

1.0 7.11 -25 0.27 0.02 0.03 0.04 0.19 3.67 0.52 10.33 0.80 18.81 4.17 0.96

1.0 7.19 -30 0.27 0.02 0.05 0.04 0.17 3.83 0.54 11.52 0.67 20.93 4.76 1.04
19

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 6: Mouth of Howard Bay, North (Squaw Point)

-0.5 > 63 μm 0.90 0.55 0.05 0.18 0.05 0.28 7.25 0.83 12.70 1.63 17.28 4.63 1.17

-1.5 0.87 0.50 0.03 0.14 0.05 0.29 6.75 0.79 12.38 1.05 19.33 5.52 1.23

-2.5 0.77 0.46 0.03 0.14 0.05 0.24 6.52 0.78 12.91 0.80 21.01 5.15 1.24

-3.5 0.76 0.42 0.02 0.12 0.05 0.23 6.29 0.74 12.42 0.82 20.81 5.52 1.25

-4.5 0.78 0.44 0.02 0.10 0.05 0.28 6.17 0.71 12.61 0.68 18.21 5.22 1.20

-0.5 < 63 μm 0.09 0.71 NA NA NA NA 6.64 0.68 12.72 NA 19.50 4.99 1.18

-1.5 0.13 0.47 0.03 0.14 0.05 0.25 6.01 0.65 11.47 0.92 18.39 5.14 1.13

-2.5 0.22 0.47 0.02 0.11 0.04 0.30 5.74 0.63 11.54 0.72 20.60 5.26 1.13

-3.5 0.23 0.40 0.02 0.05 0.05 0.28 5.40 0.58 11.48 0.69 19.47 4.78 1.13

-4.5 0.21 0.42 0.02 0.05 0.05 0.31 5.33 0.57 11.57 0.61 19.83 4.76 1.11

4.9 0.93 6.21 -0.5 All particles 0.56 0.04 0.16 0.04 0.25 7.13 0.81 12.60 1.46 17.34 4.15 1.16

4.9 0.91 6.61 -1.5 0.49 0.03 0.14 0.05 0.28 6.65 0.77 12.26 1.03 19.20 5.47 1.22

4.9 0.91 7.15 -2.5 0.46 0.03 0.13 0.05 0.25 6.26 0.74 12.44 0.77 20.65 5.11 1.20

4.9 0.90 6.57 -3.5 0.41 0.02 0.10 0.05 0.24 6.03 0.70 12.09 0.78 20.31 5.30 1.21

4.9 0.89 6.67 -4.5 0.43 0.02 0.08 0.05 0.28 5.95 0.68 12.30 0.66 18.43 5.08 1.17

-10 > 63 μm 0.62 0.35 0.02 0.08 0.04 0.22 5.66 0.80 10.39 0.53 19.33 4.77 0.96

-15 0.63 0.26 0.03 0.03 0.04 0.16 5.34 0.77 8.42 0.82 15.75 4.06 0.79

-20 0.66 0.22 0.04 0.07 0.05 0.06 5.63 0.79 9.26 0.67 16.70 4.43 0.88

-25 0.64 0.26 0.05 0.07 0.07 0.06 5.47 0.75 10.28 0.77 18.78 5.38 0.98

-30 0.64 0.28 0.06 0.09 0.05 0.07 4.82 0.65 8.94 0.46 15.55 4.23 0.82

-10 < 63 μm 0.38 0.52 0.02 0.06 0.04 0.40 4.67 0.57 9.43 0.49 16.25 3.97 0.87

-15 0.37 0.36 0.02 0.05 0.04 0.24 4.72 0.60 8.98 0.73 16.09 4.64 0.85

-20 0.34 0.51 0.04 0.06 0.05 0.36 4.41 0.57 8.67 0.54 16.25 3.94 0.81

-25 0.36 0.47 0.04 0.05 0.04 0.34 4.15 0.55 8.57 0.55 14.02 3.56 0.73

-30 0.36 0.35 0.06 0.06 0.05 0.18 3.97 0.50 8.69 0.51 16.79 3.98 0.76

4.9 7.08 -10 All particles 0.42 0.02 0.07 0.04 0.29 5.28 0.71 10.02 0.51 18.16 4.47 0.93

4.9 6.96 -15 0.30 0.03 0.04 0.04 0.19 5.12 0.71 8.63 0.79 15.88 4.27 0.81

4.9 7.83 -20 0.32 0.04 0.07 0.05 0.16 5.22 0.72 9.06 0.63 16.55 4.26 0.85

4.9 7.95 -25 0.34 0.05 0.06 0.06 0.16 4.99 0.68 9.66 0.69 17.06 4.72 0.89

4.9 7.42 -30 0.30 0.06 0.08 0.05 0.11 4.51 0.60 8.85 0.48 16.00 4.14 0.80
20

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 7: West of Hanks Marsh

-0.5 > 63 μm 0.77 0.58 0.06 0.13 0.05 0.33 6.71 0.75 15.25 2.01 22.09 6.90 1.33

-1.5 0.76 0.53 0.03 0.12 0.06 0.32 6.93 0.79 15.77 2.40 20.48 6.11 1.32

-2.5 0.76 0.52 0.03 0.18 0.06 0.26 6.94 0.82 16.19 2.29 21.23 6.25 1.34

-3.5 0.81 0.52 0.03 0.19 0.05 0.26 6.75 0.79 16.14 2.37 20.88 7.18 1.35

-4.5 0.78 0.52 0.02 0.15 0.05 0.30 6.91 0.80 15.57 2.45 19.23 5.29 1.26

-0.5 < 63 μm 0.21 0.53 0.07 0.13 0.08 0.26 5.37 0.56 15.01 1.74 27.35 9.20 1.42

-1.5 0.24 0.49 0.04 0.11 0.07 0.27 5.53 0.62 14.91 1.92 22.16 7.71 1.32

-2.5 0.24 0.53 0.03 0.12 0.06 0.32 5.36 0.59 14.79 2.28 22.98 8.08 1.35

-3.5 0.19 0.49 0.03 0.15 0.07 0.24 5.34 0.60 15.20 2.06 23.96 8.31 1.38

-4.5 0.21 0.50 0.02 0.18 0.06 0.23 4.37 0.62 14.99 2.29 23.57 7.29 1.32

0.8 0.93 6.84 -0.5 All particles 0.56 0.06 0.13 0.06 0.31 6.29 0.69 14.90 1.91 22.77 7.25 1.33

0.8 0.92 6.56 -1.5 0.52 0.03 0.12 0.06 0.31 6.56 0.75 15.48 2.27 20.75 6.45 1.31

0.8 0.91 6.64 -2.5 0.53 0.03 0.17 0.06 0.27 6.56 0.76 15.85 2.29 21.65 6.69 1.35

0.8 0.91 6.84 -3.5 0.51 0.03 0.18 0.06 0.25 6.46 0.75 15.89 2.30 21.35 7.36 1.35

0.8 0.91 6.40 -4.5 0.52 0.02 0.16 0.05 0.29 6.33 0.76 15.36 2.40 20.07 5.70 1.27

-10 > 63 μm 0.46 0.48 0.01 0.07 0.06 0.34 6.65 0.87 14.97 2.09 23.19 5.46 1.26

-15 0.56 0.40 0.00 0.12 0.03 0.25 5.84 0.76 14.88 1.68 20.05 7.39 1.21

-20 0.56 0.34 0.00 0.10 0.04 0.20 6.07 0.80 15.01 1.46 20.54 7.83 1.28

-25 0.60 0.41 0.00 0.11 0.05 0.26 6.32 0.82 14.58 1.52 18.17 7.25 1.27

-30 0.63 0.36 0.00 0.11 0.04 0.22 6.32 0.84 15.05 1.63 19.62 7.73 1.29

-10 < 63 μm 0.54 0.55 0.01 0.13 0.05 0.36 4.87 0.60 12.86 1.57 23.78 6.11 1.16

-15 0.44 0.39 0.00 0.08 0.06 0.26 4.30 0.51 12.80 1.39 22.69 6.44 1.16

-20 0.44 0.43 0.00 0.05 0.06 0.33 4.28 0.51 13.35 1.30 25.08 6.62 1.20

-25 0.40 0.37 0.00 0.07 0.06 0.24 4.54 0.55 13.40 1.28 26.44 7.21 1.25

-30 0.37 0.37 0.00 0.08 0.05 0.23 4.52 0.54 13.23 1.31 23.76 6.67 1.21

0.8 6.38 -10 All particles 0.52 0.01 0.10 0.05 0.35 5.69 0.72 13.83 1.81 23.51 5.81 1.20

0.8 6.30 -15 0.40 0.00 0.10 0.04 0.25 5.17 0.65 13.97 1.55 21.20 6.98 1.19

0.8 6.44 -20 0.38 0.00 0.07 0.05 0.25 5.29 0.67 14.28 1.39 22.52 7.30 1.25

0.8 6.64 -25 0.39 0.00 0.09 0.05 0.25 5.60 0.71 14.11 1.43 21.51 7.24 1.26

0.8 5.76 -30 0.36 0.00 0.10 0.05 0.22 5.65 0.73 14.38 1.51 21.15 7.34 1.26
21

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 8: Near channel north west of Squaw Point

-0.5 > 63 μm 0.86 0.43 0.01 0.08 0.12 0.21 3.34 0.39 19.63 0.99 46.43 21.14 2.26

-1.5 0.87 0.45 0.01 0.08 0.13 0.23 3.30 0.37 19.86 0.96 50.14 21.24 2.37

-2.5 0.83 0.40 0.00 0.09 0.07 0.24 3.87 0.43 15.38 1.35 32.85 12.41 1.68

-3.5 0.87 0.36 0.00 0.08 0.09 0.19 4.28 0.49 15.93 1.43 32.62 13.44 1.78

-4.5 0.92 0.31 0.01 0.08 0.08 0.14 4.50 0.50 12.71 1.07 24.92 9.76 1.34

-0.5 < 63 μm 0.15 0.36 0.02 0.14 0.06 0.14 4.63 0.53 11.32 1.19 18.07 6.34 1.08

-1.5 0.13 0.35 0.02 0.12 0.06 0.16 4.13 0.46 11.39 0.84 19.35 7.05 1.16

-2.5 0.17 0.32 0.01 0.06 0.06 0.18 3.65 0.37 9.99 0.96 17.87 6.23 0.97

-3.5 0.16 0.29 0.01 0.04 0.07 0.17 3.15 0.35 10.09 0.77 19.74 6.55 0.97

-4.5 0.11 0.30 0.01 0.09 0.06 0.14 2.89 0.33 8.89 0.57 17.76 6.16 0.85

3.0 0.86 6.33 -0.5 All particles 0.42 0.01 0.09 0.11 0.20 3.56 0.41 18.52 1.03 42.50 19.07 2.10

3.0 0.87 6.53 -1.5 0.44 0.01 0.08 0.12 0.22 3.41 0.38 18.73 0.95 46.03 19.34 2.21

3.0 0.89 4.86 -2.5 0.38 0.00 0.08 0.07 0.23 3.83 0.42 14.45 1.28 30.28 11.35 1.56

3.0 0.90 5.22 -3.5 0.36 0.00 0.08 0.09 0.19 4.24 0.48 15.53 1.38 31.66 12.79 1.71

3.0 0.91 5.76 -4.5 0.32 0.01 0.09 0.08 0.15 4.46 0.50 12.67 1.05 24.88 9.66 1.32

-10 > 63 μm 0.59 0.32 0.01 0.04 0.04 0.22 5.10 0.64 16.70 0.41 30.95 9.49 1.59

-15 0.59 0.24 0.01 0.05 0.04 0.14 4.52 0.58 11.21 1.20 21.53 5.59 1.14

-20 0.44 0.26 0.02 0.04 0.04 0.15 4.76 0.61 12.42 0.82 23.85 6.15 1.28

-25 0.53 0.28 0.02 0.04 0.05 0.17 4.69 0.61 11.54 0.78 26.76 6.36 1.21

-30 0.56 0.35 0.02 0.01 0.05 0.27 3.10 0.60 11.46 0.89 26.22 6.00 1.23

-10 < 63 μm 0.41 0.28 0.01 0.04 0.03 0.20 3.88 0.45 9.70 0.78 16.03 3.73 0.88

-15 0.41 0.26 0.01 0.01 0.03 0.21 4.03 0.47 10.02 0.78 17.66 4.36 0.96

-20 0.56 0.21 0.01 0.03 0.03 0.14 3.75 0.39 9.50 0.66 17.82 4.34 0.91

-25 0.47 0.23 0.02 0.02 0.03 0.16 3.70 0.42 9.90 0.49 17.64 4.50 0.97

-30 0.44 0.20 0.02 0.02 0.03 0.13 3.54 0.37 10.83 0.57 21.76 4.95 1.03

3.0 5.87 -10 All particles 0.30 0.01 0.04 0.04 0.21 4.60 0.56 13.85 0.56 24.87 7.14 1.30

3.0 6.33 -15 0.25 0.01 0.03 0.04 0.17 4.32 0.53 10.72 1.02 19.94 5.08 1.07

3.0 7.06 -20 0.23 0.02 0.04 0.03 0.14 4.20 0.49 10.79 0.73 20.49 5.14 1.07

3.0 7.58 -25 0.26 0.02 0.03 0.04 0.17 4.22 0.52 10.77 0.64 22.45 5.48 1.10

3.0 7.54 -30 0.28 0.02 0.01 0.04 0.21 3.30 0.49 11.18 0.75 24.24 5.54 1.14
22

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 9: Mid Lake

-0.5 > 63 μm 0.85 0.30 0.00 0.06 0.11 0.13 2.23 0.23 17.76 1.02 55.99 21.33 2.16

-1.5 0.88 0.24 0.01 0.03 0.08 0.12 3.75 0.38 16.60 1.16 40.80 16.00 1.86

-2.5 0.88 0.21 0.01 0.02 0.07 0.11 3.82 0.39 16.26 0.96 30.70 9.00 1.54

-3.5 0.92 0.15 0.00 0.01 0.06 0.08 4.21 0.41 15.11 1.00 25.70 6.20 1.36

-4.5 0.94 0.08 0.00 0.00 0.05 0.02 4.29 0.44 15.53 1.07 23.13 4.47 1.23

-0.5 < 63 μm 0.17 0.34 0.00 0.08 0.10 0.16 3.85 0.42 13.10 1.33 25.50 13.09 1.61

-1.5 0.15 0.29 0.00 0.02 0.07 0.19 3.59 0.38 13.40 1.02 51.50 9.81 1.64

-2.5 0.15 0.20 0.01 0.03 0.06 0.10 2.73 0.25 12.04 0.81 20.20 10.14 1.21

-3.5 0.11 0.11 0.00 0.01 0.06 0.05 2.61 0.24 9.17 0.60 14.81 9.23 0.79

-4.5 0.09 0.16 0.01 0.01 0.00 0.14 2.79 0.24 12.63 NA 24.49 8.60 1.17

2.90 0.86 6.05 -0.5 All particles 0.31 0.00 0.06 0.11 0.14 2.55 0.27 17.32 1.09 51.98 20.37 2.11

2.90 0.87 5.73 -1.5 0.25 0.01 0.03 0.08 0.14 3.84 0.39 16.61 1.18 43.69 15.53 1.88

2.90 0.87 5.94 -2.5 0.21 0.01 0.02 0.07 0.11 3.76 0.38 16.08 0.96 29.99 9.41 1.53

2.90 0.88 5.64 -3.5 0.15 0.00 0.01 0.06 0.07 4.16 0.40 14.90 0.99 25.25 6.69 1.33

2.90 0.87 5.40 -4.5 0.08 0.00 0.01 0.05 0.03 4.28 0.44 15.72 1.01 23.92 4.96 1.27

-10 > 63 μm 0.74 0.18 0.00 0.04 0.05 0.08 4.50 0.60 16.23 0.89 20.49 3.51 1.55

-15 0.77 0.18 0.00 0.06 0.09 0.03 4.69 0.63 15.61 1.16 20.26 3.46 1.53

-20 0.75 0.19 0.00 0.05 0.08 0.06 5.09 0.66 17.93 1.09 18.72 3.16 1.68

-25 0.75 0.16 0.00 0.05 0.06 0.05 4.46 0.58 16.77 1.03 22.32 3.15 1.46

-30 NA NA NA NA NA NA NA NA NA NA NA NA NA

-10 < 63 μm 0.26 0.15 0.00 0.02 0.07 0.06 3.13 0.43 16.31 0.84 23.60 5.10 <1.52

-15 0.23 0.15 0.00 0.03 0.06 0.06 3.50 0.48 15.20 0.72 24.27 5.43 <1.54

-20 0.25 0.17 0.00 0.01 0.06 0.10 3.36 0.45 15.61 0.77 84.82 5.10 2.15

-25 0.25 0.14 0.00 0.05 0.07 0.02 3.23 0.44 17.93 0.92 21.41 4.78 <1.53

-30 NA NA NA NA NA NA NA NA NA NA NA NA NA

2.90 6.20 -10 All particles 0.17 0.00 0.04 0.05 0.08 4.15 0.56 16.25 0.88 21.30 3.92 1.55

2.90 6.25 -15 0.17 0.00 0.05 0.08 0.04 4.42 0.60 15.51 1.06 21.17 3.91 1.53

2.90 6.85 -20 0.19 0.00 0.04 0.08 0.07 4.65 0.60 17.34 1.01 35.36 3.65 1.80

2.90 6.51 -25 0.16 0.00 0.05 0.06 0.04 4.15 0.55 17.06 1.00 22.09 3.57 1.48

2.90 NA -30 NA NA NA NA NA NA NA NA NA NA NA NA
23

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 10: Near Hagelstein Park

-0.5 > 63 μm 0.82 0.53 0.03 0.21 0.07 0.22 6.52 0.76 15.83 1.32 25.88 5.98 1.28

-1.5 0.82 0.36 0.02 0.19 0.07 0.09 6.78 0.80 14.54 1.01 23.80 4.73 1.24

-2.5 0.86 0.30 0.01 0.12 0.06 0.11 6.32 0.72 14.18 0.90 26.14 5.84 1.30

-3.5 0.77 0.32 0.01 0.14 0.06 0.11 6.36 0.74 14.89 1.22 24.83 6.02 1.34

-4.5 0.78 0.38 0.00 0.04 0.06 0.27 6.18 0.71 14.80 0.80 24.57 6.17 1.32

-0.5 < 63 μm 0.21 0.33 0.03 0.10 0.10 0.10 5.13 0.59 10.52 1.22 41.88 8.89 1.35

-1.5 0.21 0.46 0.01 0.11 0.08 0.26 4.88 0.58 13.66 0.95 21.10 11.83 1.24

-2.5 0.14 0.45 0.00 0.31 0.09 0.05 5.33 0.61 11.09 0.69 28.68 7.66 1.30

-3.5 0.23 0.35 0.01 0.15 0.09 0.11 5.05 0.58 11.01 0.88 36.39 7.91 1.26

-4.5 0.22 0.38 0.01 0.10 0.08 0.19 5.08 0.58 12.29 0.75 25.18 7.26 1.35

1.6 0.92 6.48 -0.5 All particles 0.50 0.03 0.19 0.08 0.20 6.40 0.74 15.13 1.34 29.93 6.75 1.33

1.6 0.92 6.67 -1.5 0.40 0.02 0.18 0.07 0.13 6.61 0.78 14.86 1.03 24.05 6.38 1.28

1.6 0.91 6.40 -2.5 0.33 0.01 0.15 0.07 0.10 6.18 0.70 13.74 0.87 26.50 6.10 1.30

1.6 0.90 6.33 -3.5 0.32 0.01 0.14 0.07 0.11 6.06 0.70 14.01 1.14 27.45 6.45 1.32

1.6 0.89 6.50 -4.5 0.38 0.00 0.05 0.07 0.26 5.94 0.68 14.25 0.79 24.70 6.41 1.33

-10 > 63 μm 0.49 0.23 0.00 0.03 0.06 0.14 4.24 0.58 16.37 1.09 31.01 8.36 1.38

-15 0.46 0.17 0.00 0.04 0.05 0.08 3.33 0.49 18.72 1.00 29.42 6.97 1.40

-20 0.40 0.17 0.00 0.06 0.15 -0.04 4.30 0.59 24.82 2.07 41.44 12.22 1.93

-25 0.44 0.60 0.00 0.03 0.48 0.10 1.00 0.21 29.77 1.46 84.77 35.84 3.64

-30 0.90 1.21 0.00 0.02 0.55 0.64 0.20 0.09 32.28 1.05 104.15 44.75 4.44

-10 < 63 μm 0.51 0.16 0.00 0.04 0.05 0.08 3.37 0.46 13.50 0.90 24.44 4.92 1.06

-15 0.54 0.18 0.00 0.05 0.05 0.08 2.99 0.40 16.82 0.85 25.99 5.15 1.23

-20 0.60 0.10 0.00 0.04 0.06 0.00 2.97 0.40 18.57 1.13 27.42 4.91 1.23

-25 0.56 0.17 0.00 0.07 0.08 0.02 3.46 0.47 27.56 1.63 29.28 5.96 1.74

-30 0.10 0.72 0.00 0.14 0.29 0.29 3.20 0.41 43.51 4.69 44.65 11.89 4.35

1.6 6.46 -10 All particles 0.20 0.00 0.04 0.05 0.11 3.80 0.52 14.90 0.99 27.65 6.60 1.22

1.6 6.43 -15 0.18 0.00 0.05 0.05 0.08 3.14 0.44 17.69 0.92 27.55 5.98 1.31

1.6 6.23 -20 0.13 0.00 0.05 0.09 ND 3.50 0.48 21.07 1.51 33.02 7.83 1.51

1.6 5.99 -25 0.36 0.00 0.05 0.26 0.05 2.38 0.36 28.53 1.55 53.66 19.09 2.58

1.6 4.24 -30 1.15 0.00 0.03 0.52 0.60 0.51 0.12 33.45 1.43 97.92 41.31 4.43
24

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 11: Midway between Squaw Point and Eagle Ridge

-0.5 > 63 μm 0.80 0.50 0.01 0.19 0.04 0.26 7.11 0.83 13.23 1.89 23.03 5.57 1.14

-1.5 0.79 0.49 0.01 0.18 0.04 0.26 7.26 0.83 12.84 1.39 20.92 4.11 1.13

-2.5 0.81 0.43 0.00 0.07 0.04 0.31 6.83 0.78 12.82 1.19 22.82 4.27 1.17

-3.5 0.81 0.35 0.01 0.11 0.04 0.19 6.64 0.78 10.31 0.95 21.34 6.51 0.99

-4.5 0.80 0.39 0.01 0.13 0.04 0.21 6.60 0.74 13.04 0.92 20.14 6.12 1.17

-0.5 < 63 μm 0.20 0.51 0.01 0.17 0.00 0.33 6.14 0.72 12.38 1.84 17.82 3.36 1.11

-1.5 0.21 0.46 0.01 0.12 0.04 0.29 6.11 0.68 11.84 1.37 17.60 4.99 1.12

-2.5 0.19 0.43 0.01 0.04 0.02 0.36 5.83 0.64 11.99 1.20 17.74 2.70 1.14

-3.5 0.19 0.44 0.02 0.11 0.04 0.27 5.83 0.66 11.40 0.95 21.43 4.22 1.13

-4.5 0.20 0.36 0.01 0.10 0.05 0.21 5.45 0.61 11.60 0.87 20.82 2.43 1.15

2.3 0.93 6.16 -0.5 All particles 0.50 0.01 0.19 0.03 0.27 6.91 0.81 13.06 1.88 21.97 5.12 1.14

2.3 0.92 6.02 -1.5 0.49 0.01 0.17 0.04 0.26 7.02 0.80 12.63 1.38 20.24 4.29 1.13

2.3 0.91 5.84 -2.5 0.43 0.01 0.06 0.04 0.32 6.64 0.75 12.66 1.20 21.84 3.97 1.16

2.3 0.90 6.61 -3.5 0.37 0.01 0.11 0.04 0.20 6.48 0.76 10.52 0.95 21.35 6.07 1.02

2.3 0.90 6.35 -4.5 0.39 0.01 0.13 0.04 0.21 6.37 0.71 12.76 0.91 20.27 5.39 1.17

-10 > 63 μm 0.58 0.39 0.05 0.07 0.04 0.23 6.66 0.95 13.00 0.59 20.19 12.80 1.09

-15 0.59 0.32 0.04 0.04 0.03 0.21 6.33 0.92 12.38 0.55 20.83 12.92 1.07

-20 0.58 0.33 0.03 0.05 0.04 0.20 6.41 0.95 11.81 0.74 21.34 13.59 1.05

-25 0.64 0.30 0.03 0.05 0.04 0.19 5.75 0.85 11.16 0.70 20.55 13.90 1.01

-30 0.64 0.21 0.04 0.05 0.04 0.08 5.36 0.77 10.55 1.38 21.26 14.13 0.97

-10 < 63 μm 0.42 0.39 0.07 0.07 0.07 0.19 5.13 0.69 11.64 0.64 19.92 4.45 1.08

-15 0.41 0.28 0.03 0.04 0.05 0.16 4.83 0.68 11.55 0.54 21.48 13.21 0.99

-20 0.42 0.24 0.03 0.03 0.04 0.15 4.64 0.65 9.55 0.52 17.66 12.68 0.83

-25 0.36 0.28 0.02 0.03 0.03 0.19 4.07 0.58 8.76 0.49 17.77 13.35 0.80

-30 0.36 0.25 0.03 0.04 0.05 0.12 3.75 0.53 8.77 0.56 16.79 13.90 0.79

2.3 6.62 -10 All particles 0.39 0.06 0.07 0.05 0.21 6.02 0.84 12.43 0.61 20.08 9.30 1.08

2.3 6.72 -15 0.30 0.03 0.04 0.04 0.19 5.72 0.82 12.04 0.54 21.09 13.04 1.04

2.3 6.65 -20 0.29 0.03 0.04 0.04 0.18 5.66 0.82 10.85 0.65 19.78 13.20 0.96

2.3 6.48 -25 0.29 0.03 0.04 0.03 0.19 5.15 0.75 10.31 0.62 19.56 13.70 0.94

2.3 6.57 -30 0.23 0.04 0.05 0.05 0.10 4.78 0.68 9.91 1.08 19.65 14.04 0.90
25

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 12: North of Mid Lake

-0.5 > 63 μm 0.75 0.37 0.01 0.15 0.08 0.13 5.95 0.66 15.84 1.49 32.56 10.45 1.72

-1.5 0.79 0.35 0.01 0.09 0.07 0.18 5.28 0.57 15.34 1.09 24.85 8.73 1.51

-2.5 0.76 0.40 0.00 0.09 0.06 0.25 5.25 0.59 14.96 1.23 26.71 9.82 1.56

-3.5 0.77 0.44 0.00 0.04 0.06 0.33 5.52 0.61 15.74 0.89 29.67 10.24 1.62

-4.5 0.79 0.45 0.01 0.10 0.06 0.29 5.76 0.61 16.91 0.87 34.70 11.56 1.76

-0.5 < 63 μm 0.25 0.42 0.02 0.11 0.10 0.18 5.18 0.50 15.67 1.36 31.08 10.70 1.63

-1.5 0.21 0.34 0.02 0.07 0.09 0.17 4.37 0.46 14.29 0.87 27.70 9.17 1.53

-2.5 0.24 0.34 0.01 0.07 0.08 0.19 4.84 0.46 14.34 0.85 28.13 8.58 1.49

-3.5 0.23 0.34 0.01 0.08 0.08 0.17 4.55 0.43 15.12 0.71 28.03 8.28 1.52

-4.5 0.21 0.33 0.01 0.08 0.09 0.15 4.70 0.42 15.28 0.70 29.34 8.86 1.57

2.2 0.90 6.16 -0.5 All particles 0.38 0.02 0.14 0.09 0.14 5.75 0.62 15.80 1.46 32.19 10.51 1.69

2.2 0.89 5.70 -1.5 0.35 0.01 0.08 0.08 0.18 5.09 0.55 15.13 1.05 25.44 8.82 1.51

2.2 0.89 5.66 -2.5 0.39 0.00 0.08 0.07 0.23 5.15 0.56 14.81 1.14 27.06 9.51 1.55

2.2 0.88 5.88 -3.5 0.42 0.00 0.05 0.06 0.30 5.29 0.57 15.60 0.85 29.29 9.79 1.60

2.2 0.89 5.83 -4.5 0.42 0.01 0.09 0.06 0.26 5.53 0.57 16.57 0.84 33.56 10.99 1.72

-10 > 63 μm 0.63 0.22 0.00 0.03 0.04 0.15 5.61 0.80 9.92 0.69 17.72 3.73 0.93

-15 0.61 0.29 0.01 0.04 0.04 0.20 5.32 0.74 9.59 0.71 18.90 4.04 0.92

-20 0.57 0.33 0.00 0.04 0.06 0.23 5.11 0.70 9.78 0.94 21.15 5.37 1.00

-25 0.54 0.21 0.01 0.05 0.04 0.11 4.56 0.59 10.66 0.73 24.22 5.02 1.13

-30 0.51 0.17 0.01 0.04 0.04 0.09 3.66 0.54 9.68 0.68 21.53 3.75 1.03

-10 < 63 μm 0.37 0.27 0.00 0.02 0.04 0.20 3.26 0.51 10.02 0.51 21.40 14.15 0.94

-15 0.39 0.22 0.01 0.03 0.05 0.13 3.15 0.51 10.89 0.70 24.13 6.47 1.12

-20 0.43 0.35 0.00 0.02 0.06 0.27 3.01 0.49 10.96 0.69 25.09 6.54 1.22

-25 0.46 0.18 0.01 0.03 0.05 0.08 2.86 0.47 10.20 0.61 22.93 4.94 1.04

-30 0.49 0.25 0.01 0.03 0.04 0.18 3.65 0.42 8.92 0.54 20.27 3.63 0.92

2.2 6.55 -10 All particles 0.24 0.00 0.02 0.04 0.17 4.74 0.69 9.96 0.62 19.08 7.57 0.93

2.2 6.61 -15 0.26 0.01 0.03 0.04 0.18 4.47 0.65 10.09 0.70 20.94 4.99 1.00

2.2 5.99 -20 0.34 0.00 0.03 0.06 0.24 4.20 0.61 10.29 0.83 22.86 5.88 1.10

2.2 6.76 -25 0.20 0.01 0.04 0.05 0.10 3.79 0.53 10.45 0.67 23.63 4.98 1.09

2.2 6.64 -30 0.21 0.01 0.03 0.04 0.13 3.65 0.48 9.30 0.61 20.91 3.69 0.97
26

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 13: South of Modoc Point

-0.5 > 63 μm 0.75 0.35 0.04 0.13 0.09 0.09 4.69 0.47 18.47 1.01 40.49 13.62 1.78

-1.5 0.78 0.33 0.01 0.15 0.09 0.08 4.85 0.47 17.63 1.20 34.65 11.96 1.71

-2.5 0.80 0.32 0.01 0.14 0.07 0.09 4.80 0.47 17.47 1.05 33.82 11.24 1.70

-3.5 0.82 0.31 0.01 0.08 0.07 0.16 5.07 0.51 16.96 0.92 30.24 9.09 1.56

-4.5 0.81 0.39 0.02 0.04 0.05 0.28 6.51 0.80 13.78 0.76 20.96 4.57 1.28

-0.5 < 63 μm 0.25 0.43 0.03 0.02 0.10 0.28 4.47 0.42 17.58 1.06 34.29 11.58 1.78

-1.5 0.22 0.37 0.02 0.02 0.10 0.23 4.36 0.38 16.94 0.94 33.23 10.41 1.71

-2.5 0.20 0.36 0.01 0.02 0.09 0.24 3.86 0.34 16.54 0.96 29.35 10.48 1.70

-3.5 0.18 0.38 0.01 0.02 0.09 0.26 4.20 0.37 17.19 0.91 31.32 11.35 1.56

-4.5 0.19 0.45 0.03 0.05 0.06 0.31 5.47 0.52 14.06 0.69 23.10 6.56 1.28

1.5 0.91 6.81 -0.5 All particles 0.37 0.04 0.10 0.09 0.14 4.64 0.46 18.25 1.02 38.94 13.11 1.78

1.5 0.90 6.48 -1.5 0.34 0.01 0.12 0.09 0.11 4.74 0.45 17.48 1.14 34.33 11.62 1.71

1.5 0.89 6.41 -2.5 0.33 0.01 0.12 0.07 0.12 4.61 0.44 17.28 1.03 32.91 11.09 1.70

1.5 0.89 6.41 -3.5 0.32 0.01 0.07 0.07 0.17 4.91 0.48 17.00 0.92 30.43 9.50 1.56

1.5 0.91 6.22 -4.5 0.40 0.02 0.04 0.05 0.29 6.32 0.75 13.83 0.75 21.36 4.94 1.28

-10 > 63 μm 0.55 0.23 0.02 0.04 0.05 0.13 5.30 0.64 14.09 0.91 26.56 5.74 1.35

-15 0.59 0.22 0.03 0.04 0.04 0.12 5.35 0.66 12.56 0.72 24.08 4.85 1.14

-20 0.57 0.21 0.03 0.04 0.03 0.12 5.40 0.65 10.91 0.66 20.57 4.53 1.05

-25 0.62 0.27 0.03 0.02 0.04 0.18 5.46 0.82 9.86 0.63 18.95 4.03 0.92

-30 0.62 0.28 0.03 0.04 0.04 0.17 4.81 0.69 9.93 0.72 17.56 4.36 0.88

-10 < 63 μm 0.45 0.66 0.02 0.04 0.06 0.53 4.66 0.63 14.48 0.86 29.98 6.78 1.53

-15 0.41 0.28 0.03 0.02 0.05 0.18 4.33 0.61 11.33 0.62 21.32 4.62 1.12

-20 0.43 0.32 0.02 0.03 0.04 0.23 4.45 0.64 9.68 0.53 20.14 4.07 1.01

-25 0.38 0.29 0.02 0.05 0.04 0.18 4.31 0.62 9.12 0.52 18.35 5.51 0.93

-30 0.38 0.15 0.02 0.03 0.05 0.05 4.12 0.59 10.32 0.65 25.27 5.14 1.00

1.5 6.65 -10 All particles 0.43 0.02 0.04 0.05 0.31 5.01 0.64 14.26 0.89 28.09 6.20 1.43

1.5 6.72 -15 0.25 0.03 0.03 0.04 0.15 4.94 0.64 12.06 0.68 22.96 4.76 1.13

1.5 6.99 -20 0.26 0.02 0.03 0.04 0.17 4.99 0.64 10.38 0.60 20.38 4.33 1.03

1.5 7.10 -25 0.27 0.02 0.03 0.04 0.18 5.02 0.75 9.58 0.59 18.73 4.59 0.92

1.5 6.99 -30 0.23 0.02 0.03 0.04 0.13 4.55 0.65 10.08 0.69 20.52 4.66 0.92
27

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 14: Ball Bay

-0.5 > 63 μm 0.82 0.56 0.02 0.20 0.05 0.31 7.77 0.98 15.08 1.71 22.52 3.14 1.33

-1.5 0.75 0.57 0.02 0.20 0.04 0.31 7.73 0.98 14.86 1.26 23.18 3.09 1.36

-2.5 0.77 0.52 0.02 0.20 0.06 0.24 8.35 1.05 14.99 1.37 22.39 3.01 1.31

-3.5 0.83 0.45 0.01 0.16 0.05 0.23 8.49 1.10 16.21 1.07 22.43 3.27 1.33

-4.5 0.79 0.51 0.01 0.14 0.04 0.33 8.23 1.06 17.02 0.84 22.66 2.94 1.34

-0.5 < 63 μm 0.18 0.48 0.02 0.19 0.05 0.23 6.64 0.80 1.82

-1.5 0.25 0.02 0.15 0.04 6.36 0.78 13.62 1.15 21.26 5.10 1.19

-2.5 0.23 0.47 0.01 0.13 0.04 0.29 6.36 0.76 0.87

-3.5 0.17 0.39 0.02 0.12 0.04 0.21 6.20 0.74 14.05 0.81 22.08 5.30 1.20

-4.5 0.21 0.41 0.01 0.11 0.04 0.26 6.17 0.74 14.43 0.77 22.42 5.25 1.23

1.0 0.88 5.99 -0.5 All particles 0.55 0.02 0.19 0.05 0.29 7.57 0.95 12.39 1.73 18.49 2.58 1.09

1.0 0.91 6.72 -1.5 0.43 0.02 0.19 0.04 0.23 7.38 0.93 14.54 1.23 22.69 3.60 1.32

1.0 0.88 6.25 -2.5 0.50 0.02 0.18 0.05 0.25 7.88 0.98 11.48 1.25 17.15 2.31 1.00

1.0 0.90 6.20 -3.5 0.44 0.02 0.15 0.05 0.23 8.10 1.04 15.84 1.03 22.37 3.62 1.31

1.0 0.88 6.17 -4.5 0.49 0.01 0.13 0.04 0.31 7.80 1.00 16.49 0.83 22.61 3.42 1.32

-10 > 63 μm 0.76 0.22 0.00 0.08 0.03 0.11 6.80 0.96 13.66 0.89 18.77 <2.49 1.08

-15 0.57 0.22 0.00 0.06 0.02 0.13 5.94 0.79 10.82 0.71 19.18 <2.48 1.02

-20 0.66 0.16 0.01 0.06 0.02 0.07 5.75 0.77 12.16 0.44 19.67 <2.50 1.06

-25 0.65 0.12 0.01 0.04 0.02 0.05 6.24 0.86 10.83 0.35 17.91 <2.49 1.00

-30 0.67 0.13 0.01 0.03 0.02 0.07 5.94 0.85 9.49 0.32 15.73 <2.49 0.90

-10 < 63 μm 0.24 0.29 0.00 0.05 0.02 0.21 4.69 0.65 11.00 0.58 17.67 4.10 0.88

-15 0.43 0.19 0.00 0.04 0.02 0.14 3.87 0.52 8.09 0.44 14.46 2.87 0.70

-20 0.34 0.22 0.00 0.03 0.02 0.17 3.63 0.49 9.16 0.29 14.24 2.72 0.68

-25 0.35 0.21 0.00 0.02 0.02 0.16 4.21 0.56 8.34 0.25 12.92 <2.49 0.67

-30 0.33 0.14 0.00 0.02 0.01 0.11 3.73 0.50 7.29 0.19 11.52 <2.50 0.59

1.0 5.76 -10 All particles 0.24 0.00 0.07 0.03 0.14 6.29 0.88 13.02 0.82 18.50 1.36 1.03

1.0 5.89 -15 0.21 0.00 0.05 0.02 0.13 5.04 0.67 9.64 0.60 17.13 1.51 0.88

1.0 6.48 -20 0.18 0.01 0.05 0.02 0.10 5.03 0.67 11.14 0.39 17.82 1.26 0.93

1.0 6.55 -25 0.15 0.01 0.03 0.02 0.09 5.52 0.75 9.95 0.32 16.16 0.49 0.88

1.0 7.05 -30 0.13 0.01 0.03 0.02 0.08 5.21 0.74 8.77 0.28 14.35 0.50 0.80
28

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 15: Shoalwater Bay

-0.50 > 63 μm 0.59 0.59 0.06 0.15 0.05 0.34 9.17 1.05 15.00 4.30 21.10 5.73 1.25

-1.50 0.75 0.55 0.04 0.14 0.04 0.33 8.48 1.00 14.26 1.82 21.43 5.52 1.24

-2.50 0.73 0.47 0.05 0.10 0.04 0.28 8.36 1.01 14.98 1.28 22.11 5.48 1.28

-3.50 0.68 0.47 0.03 0.08 0.04 0.32 8.38 1.00 15.97 1.26 23.01 5.65 1.35

-4.50 0.61 0.47 0.03 0.07 0.04 0.32 8.45 1.02 14.95 1.12 22.10 5.29 1.29

-0.50 < 63 μm 0.41 0.62 0.06 0.14 0.05 0.36 7.47 0.85 12.78 2.34 19.57 5.28 1.11

-1.50 0.25 0.55 0.06 0.13 0.06 0.31 6.88 0.82 12.58 1.65 20.38 5.13 1.13

-2.50 0.27 0.50 0.04 0.08 0.04 0.34 6.47 0.76 12.62 1.13 20.37 5.04 1.14

-3.50 0.32 0.42 0.04 0.07 0.05 0.26 6.54 0.75 13.19 1.15 20.93 4.98 1.16

-4.50 0.39 0.44 0.03 0.06 0.05 0.30 6.22 0.72 10.75 0.88 16.71 3.77 0.89

1.0 0.86 5.76 -0.50 All particles 0.60 0.06 0.15 0.05 0.35 8.47 0.97 14.09 3.50 20.47 5.55 1.19

1.0 0.90 6.48 -1.50 0.55 0.05 0.14 0.05 0.32 8.08 0.95 13.84 1.78 21.16 5.42 1.21

1.0 0.89 6.68 -2.50 0.48 0.05 0.10 0.04 0.30 7.84 0.94 14.34 1.24 21.63 5.36 1.24

1.0 0.88 6.21 -3.50 0.45 0.03 0.08 0.04 0.30 7.79 0.92 15.07 1.22 22.34 5.43 1.28

1.0 0.87 6.61 -4.50 0.45 0.03 0.07 0.05 0.31 7.58 0.90 13.31 1.03 19.99 4.70 1.14

-10 > 63 μm 0.57 0.32 0.01 0.03 0.03 0.24 6.53 0.88 12.75 0.43 18.34 4.10 1.06

-15 0.60 0.23 0.01 0.06 0.03 0.13 4.52 0.61 8.37 0.53 14.81 3.04 0.80

-20 0.48 0.24 0.01 0.03 0.03 0.17 5.21 0.68 10.38 0.49 18.40 3.63 1.00

-25 0.51 0.31 0.02 0.03 0.03 0.22 5.14 0.67 11.85 0.78 22.98 4.29 1.15

-30 0.42 0.30 0.01 0.05 0.04 0.20 5.89 0.74 13.74 0.65 24.08 4.63 1.28

-10 < 63 μm 0.43 0.28 0.01 0.03 0.05 0.20 4.43 0.54 9.52 0.48 13.02 3.98 0.81

-15 0.40 0.19 0.01 0.03 0.05 0.11 4.01 0.51 7.84 0.52 11.58 3.00 0.71

-20 0.52 0.30 0.01 ND 0.03 0.29 4.04 0.51 8.05 0.48 11.27 2.86 0.72

-25 0.49 0.19 0.01 0.03 0.04 0.12 3.87 0.49 9.07 0.42 13.20 3.17 0.78

-30 0.58 0.19 0.01 0.02 0.04 0.12 3.79 0.46 9.85 0.47 13.24 2.75 0.77

1.0 6.62 -10 All particles 0.30 0.01 0.03 0.04 0.22 5.64 0.74 11.37 0.45 16.07 4.05 0.95

1.0 6.47 -15 0.21 0.01 0.04 0.04 0.12 4.32 0.57 8.16 0.53 13.52 3.02 0.77

1.0 6.30 -20 0.27 0.01 0.00 0.03 0.23 4.60 0.59 9.16 0.48 14.69 3.23 0.85

1.0 6.56 -25 0.25 0.01 0.03 0.03 0.17 4.52 0.58 10.50 0.60 18.22 3.74 0.97

1.0 7.17 -30 0.24 0.01 0.03 0.04 0.15 4.67 0.58 11.48 0.55 17.79 3.54 0.99
29

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 16: Bare Island

-0.5 > 63 μm 0.76 0.50 0.03 0.13 0.05 0.29 6.81 0.83 13.75 1.56 20.03 4.98 1.22

-1.5 0.81 0.52 0.02 0.12 0.05 0.34 6.61 0.82 13.49 1.40 19.43 5.14 1.22

-2.5 0.80 0.42 0.02 0.08 0.05 0.28 6.37 0.79 13.04 1.07 19.52 5.21 1.24

-3.5 0.76 0.45 0.02 0.09 0.06 0.28 6.61 0.85 13.97 0.87 21.05 5.21 1.27

-4.5 0.83 0.36 0.01 0.06 0.07 0.22 5.32 0.65 16.20 1.20 29.01 8.59 1.52

-0.5 < 63 μm 0.24 0.44 0.03 0.12 0.06 0.23 0.83 0.69 13.31 1.38 21.25 6.34 1.22

-1.5 0.19 0.45 0.02 0.10 0.06 0.27 0.82 0.69 13.42 1.57 21.48 6.30 1.22

-2.5 0.22 0.41 0.02 0.10 0.06 0.24 0.79 0.65 13.31 1.02 22.87 6.46 1.25

-3.5 0.25 0.40 0.03 0.07 0.06 0.24 0.85 0.63 13.34 0.68 22.24 6.29 1.25

-4.5 0.18 0.31 0.01 0.05 0.11 0.14 0.65 0.48 17.87 1.08 34.11 12.15 1.82

2.1 0.93 6.13 -0.5 All particles 0.49 0.03 0.13 0.05 0.27 5.38 0.80 13.64 1.51 20.32 5.30 1.22

2.1 0.92 6.21 -1.5 0.51 0.02 0.12 0.05 0.33 5.50 0.80 13.48 1.43 19.82 5.36 1.22

2.1 0.91 6.32 -2.5 0.43 0.02 0.08 0.05 0.27 5.24 0.77 13.31 1.08 20.57 5.57 1.26

2.1 0.91 6.61 -3.5 0.44 0.02 0.08 0.06 0.27 5.23 0.80 13.97 0.83 21.60 5.55 1.28

2.1 0.87 6.38 -4.5 0.36 0.01 0.06 0.08 0.21 4.53 0.62 16.58 1.19 30.08 9.27 1.58

-10 > 63 μm 0.53 0.32 0.01 0.06 0.05 0.20 6.24 0.83 13.35 0.67 20.41 4.60 1.22

-15 0.53 0.29 0.01 0.09 0.05 0.13 6.11 0.82 13.29 1.09 23.18 4.48 1.25

-20 0.48 0.39 0.02 0.10 0.05 0.23 6.29 0.83 12.77 0.66 24.39 4.28 1.23

-25 0.54 0.36 0.03 0.09 0.06 0.18 6.41 0.81 11.83 0.59 24.16 3.68 1.15

-30 0.57 0.36 0.04 0.08 0.05 0.19 6.01 0.77 11.16 0.50 22.63 3.75 1.05

-10 < 63 μm 0.47 0.17 0.01 0.06 0.05 0.05 4.41 0.50 12.10 0.55 22.39 4.94 1.14

-15 0.47 0.23 0.01 0.08 0.05 0.10 4.48 0.53 10.27 0.92 21.62 4.31 1.02

-20 0.52 0.27 0.02 0.01 0.04 0.20 4.47 0.53 11.38 0.68 21.78 4.20 1.11

-25 0.46 0.18 0.03 0.08 0.05 0.01 4.47 0.52 10.49 0.56 20.14 4.45 1.02

-30 0.43 0.47 0.04 0.07 0.04 0.32 4.39 0.52 10.01 0.44 18.33 4.33 0.95

2.1 6.66 -10 All particles 0.25 0.01 0.06 0.05 0.13 5.38 0.68 12.76 0.62 21.34 4.76 1.18

2.1 6.52 -15 0.26 0.01 0.09 0.05 0.12 5.35 0.69 11.88 1.01 22.45 4.40 1.15

2.1 6.74 -20 0.33 0.02 0.05 0.04 0.21 5.34 0.67 12.04 0.67 23.02 4.24 1.16

2.1 6.84 -25 0.28 0.03 0.09 0.05 0.10 5.52 0.68 11.21 0.58 22.32 4.03 1.09

2.1 6.87 -30 0.40 0.04 0.08 0.05 0.24 5.32 0.67 10.67 0.48 20.79 4.00 1.01
30

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 17: Modoc Point

-0.5 > 63 μm 0.78 0.41 0.00 0.11 0.09 0.22 4.67 0.44 19.59 1.91 45.11 14.24 1.91

-1.5 0.76 0.35 0.00 0.04 0.09 0.21 5.36 0.50 18.13 1.42 33.94 9.90 1.69

-2.5 0.72 0.31 0.00 0.03 0.07 0.22 5.58 0.49 15.39 1.20 29.76 7.94 1.48

-3.5 0.71 0.35 0.00 0.04 0.08 0.24 5.58 0.51 16.19 1.19 31.27 11.02 1.68

-4.5 0.74 0.34 0.00 0.01 0.06 0.27 5.53 0.49 18.42 1.20 30.72 9.19 1.62

-0.5 < 63 μm 0.23 0.44 0.00 0.13 0.11 0.19 4.55 0.43 17.52 1.75 41.23 12.10 1.90

-1.5 0.27 0.36 0.00 0.09 0.09 0.17 4.37 0.41 16.71 1.20 37.08 10.48 1.67

-2.5 0.28 0.24 0.00 0.13 0.09 0.02 4.36 0.42 10.42 1.03 25.42 7.44 1.28

-3.5 0.29 0.34 0.00 0.09 0.08 0.17 4.50 0.43 14.84 1.12 35.51 8.41 1.59

-4.5 0.26 0.34 0.00 0.09 0.08 0.17 4.52 0.42 14.52 1.07 30.98 8.23 1.58

1.8 0.89 5.68 -0.5 All particles 0.42 0.00 0.11 0.09 0.22 4.69 0.44 19.31 1.89 44.66 13.89 1.92

1.8 0.90 6.15 -1.5 0.36 0.00 0.06 0.09 0.21 5.22 0.49 18.18 1.39 35.58 10.29 1.72

1.8 0.90 6.40 -2.5 0.29 0.00 0.06 0.07 0.16 5.24 0.47 13.99 1.15 28.54 7.80 1.42

1.8 0.89 6.34 -3.5 0.35 0.00 0.05 0.08 0.22 5.26 0.49 15.79 1.17 32.52 10.26 1.66

1.8 0.88 6.33 -4.5 0.34 0.00 0.03 0.07 0.24 5.27 0.47 17.40 1.17 30.79 8.94 1.61

-10 > 63 μm 0.51 0.27 0.01 0.06 0.05 0.16 6.34 0.89 14.47 0.85 26.36 5.98 1.36

-15 0.54 0.14 0.01 0.05 0.04 0.04 5.99 0.86 11.85 0.74 22.90 5.33 1.10

-20 0.46 0.16 0.02 0.05 0.06 0.03 5.52 0.76 11.20 0.80 20.29 4.84 1.07

-25 0.43 0.25 0.02 0.06 0.07 0.10 4.99 0.67 12.15 1.01 28.58 6.68 1.30

-30 0.45 0.16 0.02 0.06 0.04 0.04 5.01 0.66 11.13 0.74 24.07 5.66 1.17

-10 < 63 μm 0.49 0.30 0.01 0.07 0.06 0.16 4.29 0.58 13.59 0.69 28.36 6.87 1.37

-15 0.46 0.27 0.01 0.03 0.04 0.18 4.16 0.58 11.17 0.59 24.47 5.59 1.10

-20 0.54 0.26 0.01 0.04 0.05 0.16 3.97 0.56 9.78 0.65 21.40 5.02 0.94

-25 0.57 0.28 0.01 0.05 0.05 0.18 3.93 0.55 10.66 0.72 21.18 4.78 0.97

-30 0.55 0.23 0.01 0.04 0.04 0.14 3.92 0.54 9.76 0.53 19.54 4.59 0.95

1.8 6.60 -10 All particles 0.29 0.01 0.06 0.05 0.16 5.35 0.74 8.10 0.77 14.93 3.41 0.76

1.8 6.57 -15 0.20 0.01 0.04 0.04 0.11 5.14 0.73 11.53 0.67 23.63 5.45 1.10

1.8 6.47 -20 0.21 0.01 0.04 0.06 0.10 4.69 0.65 10.44 0.72 20.88 4.94 1.00

1.8 6.32 -25 0.26 0.01 0.05 0.06 0.14 4.39 0.60 11.30 0.84 24.35 5.59 1.11

1.8 6.69 -30 0.20 0.01 0.05 0.04 0.10 4.41 0.59 10.38 0.62 21.59 5.07 1.05
31

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 18: Mouth of Ball Bay

-0.5 > 63 μm 0.74 0.56 0.01 0.18 0.04 0.34 7.39 0.86 13.90 1.75 20.03 3.56 1.16

-1.5 0.74 0.48 0.01 0.14 0.04 0.29 7.31 0.84 13.28 1.18 21.20 3.89 1.17

-2.5 0.69 0.46 0.01 0.14 0.04 0.27 7.10 0.82 12.81 1.08 22.59 4.07 1.17

-3.5 0.77 0.29 0.00 0.07 0.04 0.18 6.83 0.80 6.29 1.13 8.41 1.32 0.76

-4.5 0.75 0.44 0.00 0.07 0.04 0.33 6.86 0.81 13.06 1.08 20.38 3.92 1.15

-0.5 < 63 μm 0.26 0.48 0.01 0.17 0.04 0.26 6.39 0.64 11.67 1.64 12.91 3.67 0.99

-1.5 0.26 0.42 0.01 0.13 0.04 0.24 6.19 0.61 11.70 1.15 16.90 3.67 1.06

-2.5 0.31 0.39 0.00 0.08 0.04 0.26 6.00 0.59 11.48 1.02 19.54 4.12 1.07

-3.5 0.23 0.40 0.01 0.09 0.04 0.27 5.91 0.59 11.57 1.05 17.82 4.44 1.03

-4.5 0.25 0.39 0.00 0.07 0.04 0.28 5.93 0.61 11.72 1.02 13.58 4.18 1.03

3.7 0.92 6.28 -0.5 All particles 0.54 0.01 0.18 0.04 0.32 7.13 0.80 13.32 1.72 18.18 3.59 1.12

3.7 0.91 6.34 -1.5 0.46 0.01 0.14 0.04 0.27 7.02 0.78 12.86 1.17 20.07 3.83 1.14

3.7 0.89 6.40 -2.5 0.44 0.00 0.12 0.04 0.27 6.76 0.75 12.40 1.06 21.64 4.09 1.14

3.7 0.88 6.35 -3.5 0.32 0.00 0.07 0.04 0.20 6.62 0.75 7.52 1.11 10.60 2.05 0.83

3.7 0.88 6.43 -4.5 0.43 0.00 0.07 0.04 0.32 6.63 0.76 12.73 1.07 18.70 3.99 1.12

-10 > 63 μm 0.42 0.43 0.02 0.09 0.04 0.28 6.73 0.93 15.31 0.88 25.68 4.14 1.42

-15 0.41 0.42 0.01 0.11 0.05 0.25 6.90 0.97 15.19 0.76 25.04 4.22 1.41

-20 0.41 0.35 0.01 0.11 0.05 0.19 6.87 1.00 13.53 1.01 21.68 3.83 1.25

-25 0.52 0.33 0.03 0.06 0.04 0.21 6.38 0.93 12.13 0.57 19.71 3.50 1.07

-30 0.59 0.15 0.04 0.03 0.04 0.04 4.72 0.70 8.37 3.44 15.12 2.80 0.75

-10 < 63 μm 0.58 0.33 0.02 0.09 0.05 0.17 4.95 0.68 12.14 0.80 21.53 3.75 1.17

-15 0.59 0.32 0.02 0.12 0.05 0.14 5.18 0.72 12.40 0.67 21.92 3.75 1.19

-20 0.59 0.30 0.01 0.05 0.04 0.19 4.98 0.72 12.44 0.82 20.93 3.56 1.13

-25 0.48 0.31 0.03 0.06 0.04 0.19 4.67 0.66 10.21 1.04 20.96 3.22 0.97

-30 0.41 0.33 0.02 0.01 0.04 0.26 4.36 0.60 9.12 0.48 18.23 3.51 0.84

3.7 6.75 -10 All particles 0.38 0.02 0.09 0.05 0.22 5.71 0.79 13.48 0.83 23.29 3.92 1.28

3.7 6.80 -15 0.36 0.01 0.12 0.05 0.18 5.88 0.82 13.54 0.70 23.19 3.94 1.28

3.7 6.52 -20 0.32 0.01 0.07 0.04 0.19 5.76 0.84 12.89 0.90 21.24 3.67 1.18

3.7 7.01 -25 0.32 0.03 0.06 0.04 0.20 5.56 0.80 11.21 0.79 20.31 3.37 1.02

3.7 6.91 -30 0.22 0.03 0.02 0.04 0.13 4.57 0.66 8.68 2.21 16.41 3.09 0.79
32

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 19: Eagle Point

-0.5 > 63 μm 0.70 0.49 0.03 0.16 0.05 0.25 7.29 0.88 14.61 1.69 19.40 5.39 1.23

-1.5 0.80 0.44 0.03 0.13 0.05 0.24 6.97 0.84 13.84 1.26 19.39 5.16 1.19

-2.5 0.76 0.40 0.03 0.10 0.04 0.23 6.95 0.84 13.77 0.86 18.17 4.96 1.14

-3.5 0.78 0.35 0.02 0.10 0.04 0.18 6.68 0.88 14.00 0.87 20.66 6.05 1.22

-4.5 0.80 0.47 0.01 0.05 0.04 0.36 6.63 0.89 13.50 0.57 18.46 5.61 1.17

-0.5 < 63 μm 0.30 0.34 0.03 0.12 0.05 0.14 6.19 0.75 13.73 1.61 18.64 4.86 1.16

-1.5 0.20 0.40 0.03 0.10 0.05 0.22 5.75 0.67 12.98 1.18 21.51 5.74 1.19

-2.5 0.24 0.34 0.03 0.11 0.05 0.15 5.64 0.67 12.89 0.84 20.14 5.36 1.15

-3.5 0.22 0.31 0.03 0.08 0.05 0.15 5.73 0.68 13.12 0.85 23.25 5.56 1.20

-4.5 0.20 0.31 0.02 0.05 0.05 0.19 5.51 0.63 13.46 0.78 21.11 5.43 1.19

2.7 0.93 6.78 -0.5 All particles 0.45 0.03 0.15 0.05 0.22 6.96 0.84 14.35 1.66 19.18 5.23 1.21

2.7 0.92 6.66 -1.5 0.43 0.03 0.12 0.05 0.24 6.72 0.81 13.67 1.24 19.82 5.28 1.19

2.7 0.92 6.59 -2.5 0.38 0.03 0.10 0.05 0.21 6.64 0.80 13.56 0.86 18.64 5.05 1.14

2.7 0.92 6.59 -3.5 0.34 0.03 0.09 0.04 0.17 6.47 0.84 13.81 0.87 21.23 5.95 1.21

2.7 0.91 6.42 -4.5 0.43 0.01 0.05 0.04 0.32 6.40 0.84 13.49 0.61 19.00 5.58 1.17

-10 > 63 μm 0.50 0.31 0.00 0.03 0.03 0.26 5.01 0.75 9.48 0.77 14.34 3.05 0.82

-15 0.51 0.21 0.01 0.04 0.03 0.14 4.65 0.69 8.63 1.00 28.26 3.24 0.94

-20 0.49 0.23 0.01 0.04 0.03 0.15 5.34 0.77 10.86 1.24 17.82 3.37 0.97

-25 0.50 0.32 0.02 0.05 0.03 0.22 5.10 0.72 10.80 0.38 18.53 3.19 1.01

-30 0.34 0.30 0.02 0.04 0.03 0.22 5.61 0.79 11.59 0.45 21.29 3.71 1.14

-10 < 63 μm 0.50 0.20 0.00 0.03 0.03 0.13 4.19 0.60 9.29 0.78 16.46 3.36 0.82

-15 0.49 0.14 0.01 0.02 0.03 0.08 4.13 0.59 8.99 0.60 16.80 3.48 0.82

-20 0.51 0.22 0.01 0.02 0.02 0.17 3.87 0.55 9.33 2.92 15.98 3.05 0.78

-25 0.50 0.09 0.01 0.01 0.02 0.04 3.92 0.55 9.36 0.26 18.07 3.15 0.85

-30 0.66 0.15 0.01 0.03 0.02 0.09 3.85 0.54 8.83 0.51 18.32 2.87 0.82

2.7 5.84 -10 All particles 0.26 0.00 0.03 0.03 0.20 4.60 0.67 9.39 0.77 15.40 3.21 0.82

2.7 6.31 -15 0.18 0.01 0.03 0.03 0.11 4.40 0.64 8.81 0.80 22.62 3.36 0.88

2.7 6.62 -20 0.22 0.01 0.03 0.03 0.16 4.59 0.66 10.07 2.10 16.88 3.21 0.87

2.7 6.87 -25 0.21 0.01 0.03 0.03 0.14 4.52 0.63 10.09 0.32 18.30 3.17 0.93

2.7 7.40 -30 0.20 0.01 0.03 0.02 0.13 4.45 0.63 9.77 0.49 19.34 3.16 0.93
33

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 20: North of Bare Island

-0.5 > 63 μm 0.78 0.64 0.08 0.21 0.06 0.29 7.30 0.90 14.90 2.35 21.25 5.21 1.22

-1.5 0.74 0.59 0.04 0.15 0.06 0.34 7.16 0.87 14.85 2.16 20.09 5.95 1.25

-2.5 0.73 0.57 0.04 0.12 0.05 0.37 7.13 0.88 15.13 2.34 18.93 5.75 1.23

-3.5 0.77 0.52 0.03 0.12 0.05 0.31 6.65 0.82 14.44 2.76 19.50 5.88 1.24

-4.5 0.76 0.48 0.01 0.09 0.05 0.33 6.91 0.84 14.14 1.43 20.57 5.57 1.22

-0.5 < 63 μm 0.22 0.67 0.14 0.11 0.42 6.22 0.70 14.80 24.23 9.21 1.35

-1.5 0.26 0.56 0.05 0.14 0.06 0.30 5.98 0.70 13.74 2.34 19.52 6.96 1.18

-2.5 0.27 0.55 0.04 0.08 0.05 0.37 6.05 0.71 14.42 2.29 20.61 6.82 1.19

-3.5 0.23 0.48 0.03 0.12 0.07 0.27 5.70 0.68 13.62 1.44 20.82 6.78 1.22

-4.5 0.24 0.46 0.01 0.10 0.06 0.29 5.96 0.70 14.50 1.52 23.40 7.25 1.33

2.3 0.94 5.78 -0.5 All particles 0.64 0.06 0.19 0.07 0.32 7.06 0.86 14.88 1.83 21.90 6.09 1.25

2.3 0.92 6.45 -1.5 0.58 0.05 0.14 0.06 0.33 6.85 0.83 14.55 2.21 19.94 6.21 1.23

2.3 0.91 6.51 -2.5 0.56 0.04 0.11 0.05 0.37 6.84 0.83 14.94 2.33 19.38 6.04 1.22

2.3 0.91 6.69 -3.5 0.51 0.03 0.12 0.05 0.30 6.43 0.79 14.25 2.45 19.81 6.08 1.24

2.3 0.91 5.79 -4.5 0.48 0.01 0.09 0.05 0.32 6.68 0.81 14.23 1.45 21.25 5.98 1.24

-10 > 63 μm 0.53 0.26 0.00 0.04 0.05 0.18 6.21 0.91 14.93 0.93 24.84 4.36 1.34

-15 0.46 0.32 0.01 0.10 0.04 0.17 6.63 1.02 13.24 1.15 23.18 4.02 1.24

-20 0.43 0.30 0.01 0.09 0.05 0.15 6.56 0.98 14.28 0.88 22.97 4.51 1.31

-25 0.52 0.41 0.04 0.05 0.04 0.29 6.57 1.01 11.65 0.56 21.91 3.79 1.09

-30 0.52 0.35 0.03 0.05 0.03 0.23 6.69 1.04 11.03 0.54 17.95 4.14 1.01

-10 < 63 μm 0.47 0.32 0.00 0.01 0.04 0.26 4.54 0.65 13.11 0.73 23.12 4.73 1.21

-15 0.54 0.42 0.01 0.09 0.05 0.27 4.69 0.71 11.54 0.89 20.40 3.98 1.09

-20 0.57 0.35 0.01 0.09 0.05 0.19 4.64 0.68 12.55 0.70 25.61 4.61 1.23

-25 0.48 0.22 0.03 0.07 0.05 0.07 4.59 0.69 10.63 0.46 21.28 4.21 1.00

-30 0.48 0.34 0.03 0.06 0.05 0.20 4.61 0.69 9.67 0.41 20.17 4.00 0.89

2.3 6.58 -10 All particles 0.29 0.00 0.02 0.05 0.21 5.42 0.79 14.06 0.84 24.02 4.54 1.28

2.3 6.72 -15 0.37 0.01 0.09 0.05 0.22 5.58 0.85 12.32 1.01 21.67 4.00 1.16

2.3 6.85 -20 0.33 0.01 0.09 0.05 0.17 5.47 0.81 13.29 0.78 24.48 4.57 1.26

2.3 7.11 -25 0.32 0.03 0.06 0.05 0.18 5.63 0.86 11.16 0.51 21.61 3.99 1.05

2.3 7.00 -30 0.34 0.03 0.05 0.04 0.22 5.69 0.88 10.38 0.48 19.01 4.08 0.95
34

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 21: Midway between Modoc Point and the Williamson River

-0.5 > 63 μm 0.72 0.61 0.01 0.13 0.13 0.35 5.48 0.58 28.25 2.87 51.16 17.15 2.94

-1.5 0.68 0.53 0.03 0.10 0.13 0.27 5.27 0.56 23.31 2.46 43.25 14.14 2.47

-2.5 0.71 0.47 0.05 0.07 0.12 0.23 5.56 0.47 22.39 1.90 42.34 14.48 2.42

-3.5 0.69 0.48 0.01 0.06 0.11 0.30 6.14 0.51 20.91 1.84 37.36 12.41 2.24

-4.5 0.68 0.49 0.01 0.06 0.10 0.31 5.94 0.51 18.92 1.79 32.10 10.00 1.95

-0.5 < 63 μm 0.28 0.54 0.02 0.15 0.15 0.22 4.40 0.40 21.56 3.09 41.04 15.98 2.32

-1.5 0.32 0.52 0.01 0.10 0.16 0.25 3.83 0.36 21.59 2.41 42.21 15.89 2.44

-2.5 0.29 0.40 0.01 0.07 0.14 0.18 3.78 0.33 20.34 1.65 41.61 15.37 2.34

-3.5 0.31 0.46 0.00 0.05 0.13 0.27 3.91 0.34 20.55 1.56 39.35 14.15 2.32

-4.5 0.32 0.49 0.00 0.05 0.13 0.31 3.97 0.34 20.97 1.48 39.12 13.94 2.30

1.1 0.87 6.14 -0.5 All particles 0.59 0.01 0.13 0.13 0.32 5.18 0.53 26.39 2.93 48.34 16.82 2.76

1.1 0.85 6.29 -1.5 0.52 0.02 0.10 0.14 0.27 4.81 0.50 22.76 2.45 42.92 14.70 2.46

1.1 0.85 6.24 -2.5 0.45 0.04 0.07 0.13 0.21 5.04 0.43 21.79 1.83 42.12 14.74 2.40

1.1 0.84 6.24 -3.5 0.47 0.01 0.06 0.12 0.29 5.44 0.46 20.80 1.75 37.98 12.96 2.27

1.1 0.85 6.26 -4.5 0.49 0.01 0.06 0.11 0.31 5.32 0.46 19.57 1.69 34.32 11.25 2.07

-10 > 63 μm 0.40 0.47 0.00 0.08 0.11 0.27 8.35 0.77 21.45 2.10 40.84 10.61 2.31

-15 0.50 0.34 0.01 0.05 0.07 0.21 5.87 0.71 17.73 1.63 35.07 9.54 1.92

-20 0.53 0.34 0.01 0.06 0.05 0.22 6.15 0.78 16.55 1.65 31.69 8.91 1.72

-25 0.46 0.29 0.01 0.00 0.06 0.21 5.17 0.63 14.25 1.37 30.63 9.14 1.56

-30 0.47 0.26 0.00 0.06 0.05 0.16 7.80 0.71 14.81 1.76 31.31 10.37 1.70

-10 < 63 μm 0.60 0.53 0.01 0.06 0.09 0.38 4.21 0.50 19.88 1.55 43.66 4.35 2.22

-15 0.50 0.34 0.01 0.07 0.08 0.19 4.23 0.53 16.75 1.40 34.29 9.21 1.79

-20 0.47 0.30 0.01 0.05 0.06 0.17 4.05 0.54 13.75 1.25 27.99 7.44 1.46

-25 0.54 0.21 0.02 0.09 0.05 0.05 3.77 0.49 11.89 0.98 26.31 6.58 1.20

-30 0.53 0.20 0.01 0.04 0.06 0.09 4.00 0.51 11.51 1.18 30.61 <2.49 1.20

1.1 6.40 -10 All particles 0.51 0.01 0.07 0.10 0.33 5.87 0.61 20.51 1.77 42.53 6.86 2.26

1.1 6.20 -15 0.34 0.01 0.06 0.07 0.20 5.05 0.62 17.24 1.51 34.68 9.37 1.85

1.1 5.77 -20 0.32 0.01 0.06 0.06 0.20 5.15 0.67 15.23 1.46 29.94 8.22 1.60

1.1 6.50 -25 0.25 0.01 0.05 0.06 0.12 4.42 0.56 12.98 1.16 28.31 7.77 1.37

1.1 6.40 -30 0.23 0.01 0.05 0.05 0.12 5.78 0.60 13.05 1.45 30.94 5.11 1.43
35

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 22: Mid North

-0.5 > 63 μm 0.76 0.51 0.01 0.09 0.05 0.36 6.91 0.87 13.58 1.97 17.75 3.51 1.17

-1.5 0.76 0.49 0.00 0.08 0.04 0.37 7.13 0.90 16.47 1.75 22.49 4.38 1.44

-2.5 0.77 0.47 0.00 0.06 0.04 0.37 6.96 0.87 13.12 1.49 21.85 3.58 1.22

-3.5 0.68 0.48 0.00 0.06 0.04 0.38 7.09 0.89 13.29 1.46 18.22 3.85 1.22

-4.5 0.74 0.50 0.00 0.08 0.04 0.38 7.03 0.86 13.80 1.64 20.37 4.60 1.25

-0.5 < 63 μm 0.24 0.43 0.02 0.09 0.04 0.27 5.89 0.67 13.22 1.91 17.82 5.56 1.16

-1.5 0.24 0.32 0.00 0.07 0.04 0.21 6.01 0.66 12.90 1.59 17.77 5.49 1.16

-2.5 0.23 0.42 0.00 0.06 0.04 0.31 5.97 0.66 13.59 1.67 19.54 5.87 1.23

-3.5 0.32 0.42 0.00 0.06 0.04 0.32 6.04 0.70 13.51 1.52 18.24 5.64 1.22

-4.5 0.26 0.39 0.00 0.08 0.04 0.27 5.97 0.66 13.21 1.72 19.63 6.42 1.26

2.5 0.92 6.03 -0.5 All particles 0.49 0.01 0.09 0.05 0.34 6.66 0.82 13.49 1.95 17.76 4.00 1.17

2.5 0.92 5.26 -1.5 0.45 0.00 0.08 0.04 0.33 6.86 0.84 15.60 1.71 21.33 4.65 1.37

2.5 0.91 5.11 -2.5 0.46 0.00 0.06 0.04 0.36 6.73 0.82 13.22 1.53 21.32 4.11 1.22

2.5 0.91 5.29 -3.5 0.46 0.00 0.06 0.04 0.36 6.75 0.83 13.36 1.48 18.22 4.43 1.22

2.5 0.90 5.30 -4.5 0.47 0.00 0.08 0.04 0.35 6.76 0.81 13.65 1.66 20.18 5.07 1.25

-10 > 63 μm 0.52 0.40 0.02 0.05 0.03 0.31 6.73 0.97 12.28 0.90 19.70 3.72 1.14

-15 0.55 0.17 0.02 0.04 0.02 0.09 6.46 1.00 10.94 0.84 16.48 3.92 0.95

-20 0.59 0.18 0.02 0.04 0.02 0.10 5.62 0.88 9.64 0.82 15.07 3.20 0.80

-25 0.61 0.26 0.02 0.03 0.02 0.18 5.34 0.81 9.22 0.53 15.04 3.34 0.80

-30 0.50 0.14 0.02 0.05 0.03 0.04 5.71 0.81 10.25 0.52 16.11 3.42 0.88

-10 < 63 μm 0.48 0.31 0.01 0.03 0.03 0.24 4.64 0.64 10.29 0.82 18.51 3.55 1.04

-15 0.45 0.28 0.02 0.06 0.02 0.18 4.54 0.66 7.27 0.72 14.30 2.91 0.75

-20 0.41 0.17 0.01 0.12 0.02 0.01 4.30 0.62 7.96 0.74 15.76 3.34 0.80

-25 0.39 0.22 0.02 0.03 0.03 0.15 4.09 0.56 7.13 0.41 13.92 3.57 0.72

-30 0.50 0.21 0.02 0.03 0.02 0.14 4.93 0.60 7.03 0.40 14.78 3.37 0.72

2.5 5.77 -10 All particles 0.36 0.01 0.04 0.03 0.27 5.72 0.81 11.32 0.86 19.13 3.64 1.09

2.5 6.15 -15 0.22 0.02 0.05 0.02 0.13 5.59 0.85 9.28 0.79 15.49 3.46 0.86

2.5 6.32 -20 0.18 0.01 0.08 0.02 0.06 5.07 0.77 8.94 0.79 15.36 3.26 0.80

2.5 7.23 -25 0.25 0.02 0.03 0.02 0.17 4.85 0.71 8.40 0.48 14.60 3.43 0.77

2.5 6.81 -30 0.18 0.02 0.04 0.02 0.09 5.32 0.71 8.64 0.46 15.44 3.39 0.80
36

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 23: Mouth of the Williamson River

-0.5 > 63 μm 0.69 0.69 0.01 0.13 0.09 0.46 6.23 0.70 23.02 4.14 40.40 9.57 2.19

-1.5 0.74 0.56 0.00 0.08 0.09 0.38 5.91 0.63 23.04 2.82 40.51 11.52 2.44

-2.5 0.76 0.49 0.00 0.14 0.09 0.26 5.90 0.62 22.12 2.29 44.79 12.66 2.35

-3.5 0.75 0.46 0.00 0.12 0.09 0.25 6.02 0.63 20.48 2.29 37.76 10.48 2.12

-4.5 0.77 0.46 0.00 0.11 0.09 0.25 6.32 0.67 20.50 1.99 38.95 10.90 2.11

-0.5 < 63 μm 0.31 0.61 0.01 0.31 0.09 0.20 4.89 0.47 20.53 4.04 36.62 11.15 2.10

-1.5 0.26 0.29 0.00 0.17 0.10 0.02 4.21 0.39 12.34 2.71 25.26 10.75 1.39

-2.5 0.24 0.47 0.00 0.15 0.10 0.23 4.35 0.41 19.71 2.08 41.93 13.62 2.28

-3.5 0.25 0.43 0.00 0.12 0.10 0.21 4.32 0.40 18.12 1.82 33.57 12.27 2.09

-4.5 0.23 0.42 0.00 0.08 0.09 0.25 4.28 0.39 18.52 1.76 40.79 13.21 2.07

1.0 0.89 7.72 -0.5 All particles 0.66 0.01 0.19 0.09 0.38 5.82 0.63 22.25 4.11 39.23 10.06 2.16

1.0 0.87 6.83 -1.5 0.49 0.00 0.11 0.09 0.29 5.47 0.57 20.25 2.79 36.54 11.32 2.17

1.0 0.87 6.66 -2.5 0.49 0.00 0.14 0.09 0.25 5.52 0.57 21.54 2.24 44.09 12.89 2.33

1.0 0.88 6.28 -3.5 0.45 0.00 0.12 0.09 0.24 5.60 0.57 19.90 2.17 36.72 10.92 2.11

1.0 0.88 6.04 -4.5 0.45 0.00 0.10 0.09 0.25 5.84 0.60 20.04 1.93 39.38 11.44 2.10

-10 > 63 μm 0.46 0.41 0.00 0.08 0.12 0.21 6.90 0.71 21.20 2.01 43.54 12.99 2.34

-15 0.59 0.32 0.00 0.07 0.06 0.20 6.11 0.74 14.34 1.21 25.98 7.37 1.46

-20 0.59 0.30 0.00 0.05 0.06 0.19 6.48 0.83 13.26 1.28 24.81 7.71 1.38

-25 0.60 0.38 0.00 0.06 0.07 0.26 5.86 0.73 14.02 1.09 23.78 7.61 1.39

-30 0.57 0.28 0.00 0.06 0.07 0.16 5.45 0.67 13.73 1.35 24.11 7.43 1.36

-10 < 63 μm 0.54 0.49 0.00 0.07 0.10 0.31 4.48 0.56 17.98 1.63 34.90 10.26 2.05

-15 0.41 0.36 0.00 0.04 0.06 0.25 3.86 0.54 13.03 0.87 30.77 8.09 1.51

-20 0.41 0.36 0.00 0.03 0.06 0.26 3.70 0.55 11.75 0.91 26.30 7.33 1.33

-25 0.40 0.34 0.00 0.04 0.07 0.23 3.73 0.53 13.29 0.75 31.67 <2.49 1.52

-30 0.43 0.31 0.00 0.03 0.06 0.22 3.85 0.55 12.24 0.94 25.17 <2.49 1.35

1.0 5.99 -10 All particles 0.45 0.00 0.08 0.11 0.26 5.60 0.63 19.47 1.80 38.91 11.53 2.18

1.0 6.32 -15 0.33 0.00 0.06 0.06 0.22 5.20 0.66 13.81 1.07 27.93 7.66 1.48

1.0 5.89 -20 0.33 0.00 0.04 0.06 0.22 5.33 0.71 12.64 1.13 25.43 7.56 1.36

1.0 6.54 -25 0.36 0.00 0.05 0.07 0.25 5.01 0.65 13.73 0.95 26.92 4.78 1.44

1.0 5.86 -30 0.29 0.00 0.05 0.06 0.18 4.76 0.62 13.09 1.17 24.57 4.45 1.36
37

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 24: Mouth of Pelican Bay

-0.5 > 63 μm 0.78 0.49 0.00 0.16 0.04 0.29 7.11 0.83 15.12 2.08 20.51 6.07 1.30

-1.5 0.75 0.49 0.01 0.15 0.05 0.28 7.56 0.88 14.29 1.83 17.30 4.36 1.24

-2.5 0.87 0.48 0.00 0.12 0.04 0.31 7.56 0.86 14.18 1.63 19.43 4.18 1.25

-3.5 0.76 0.42 0.01 0.14 0.04 0.23 7.59 0.88 13.10 1.24 19.46 4.75 1.19

-4.5 0.86 0.46 0.01 0.09 0.04 0.32 6.73 0.79 13.47 1.04 19.45 5.01 1.22

-0.5 < 63 μm 0.22 0.45 0.01 0.10 0.04 0.30 5.88 0.64 13.17 1.84 19.36 4.82 1.19

-1.5 0.25 0.52 0.01 0.11 0.04 0.36 6.44 0.71 14.01 1.67 21.56 4.57 1.30

-2.5 0.13 0.45 0.01 0.10 0.05 0.29 6.20 0.65 14.29 1.62 21.48 5.40 1.30

-3.5 0.24 0.44 0.01 0.10 0.05 0.28 6.22 0.68 13.38 1.28 19.63 4.06 1.19

-4.5 0.14 0.40 0.01 0.08 0.05 0.26 5.57 0.60 13.77 1.07 20.57 3.96 1.20

2.0 0.93 5.93 -0.5 All particles 0.48 0.01 0.15 0.04 0.29 6.84 0.79 14.69 2.03 20.26 5.80 1.28

2.0 0.92 5.96 -1.5 0.50 0.01 0.14 0.04 0.30 7.28 0.84 14.22 1.79 18.35 4.41 1.25

2.0 0.91 5.77 -2.5 0.47 0.00 0.12 0.04 0.31 7.38 0.83 14.19 1.63 19.70 4.34 1.26

2.0 0.91 6.41 -3.5 0.43 0.01 0.13 0.04 0.24 7.27 0.83 13.16 1.25 19.50 4.59 1.19

2.0 0.90 6.43 -4.5 0.45 0.01 0.09 0.04 0.31 6.57 0.76 13.51 1.05 19.61 4.87 1.21

-10 > 63 μm 0.64 0.32 0.03 0.03 0.03 0.24 5.08 0.84 12.05 0.56 19.14 3.40 1.06

-15 0.61 0.29 0.02 0.01 0.03 0.23 5.34 0.89 11.28 0.52 18.47 3.48 0.99

-20 0.52 0.31 0.02 0.03 0.03 0.22 5.15 0.84 10.56 0.55 18.58 3.50 0.97

-25 0.54 0.40 0.03 0.02 0.03 0.31 4.86 0.76 10.50 0.52 22.84 4.44 1.00

-30 0.52 0.37 0.03 0.03 0.04 0.27 3.88 0.63 9.94 0.97 18.84 4.01 0.97

-10 < 63 μm 0.36 0.26 0.03 0.03 0.02 0.19 3.69 0.62 10.83 0.47 20.38 3.72 0.99

-15 0.39 0.45 0.02 0.02 0.03 0.38 3.58 0.63 10.06 0.41 19.33 3.58 0.94

-20 0.48 0.27 0.03 0.02 0.02 0.20 3.37 0.59 8.65 0.44 15.69 3.09 0.77

-25 0.46 0.24 0.03 0.02 0.04 0.16 3.13 0.56 8.94 0.35 16.26 3.29 0.77

-30 0.48 0.23 0.03 0.04 0.02 0.14 2.84 0.55 8.17 0.37 15.84 2.81 0.77

2.0 6.72 -10 All particles 0.30 0.03 0.03 0.03 0.22 4.57 0.76 11.61 0.53 19.59 3.51 1.03

2.0 6.73 -15 0.36 0.02 0.02 0.03 0.29 4.65 0.79 10.81 0.48 18.81 3.52 0.97

2.0 7.13 -20 0.29 0.03 0.02 0.03 0.21 4.30 0.72 9.65 0.50 17.20 3.31 0.88

2.0 6.90 -25 0.33 0.03 0.02 0.03 0.24 4.07 0.67 9.79 0.44 19.84 3.91 0.89

2.0 7.01 -30 0.30 0.03 0.03 0.03 0.21 3.38 0.59 9.08 0.68 17.39 3.43 0.88
38

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 25: Near stream to Agency Lake, South

-0.5 > 63 μm 0.74 0.66 0.06 0.29 0.06 0.25 7.11 0.80 16.97 2.49 22.33 6.45 1.45

-1.5 0.78 0.60 0.03 0.32 0.08 0.18 6.53 0.73 17.35 3.05 24.42 6.23 1.53

-2.5 0.74 0.52 0.01 0.19 0.06 0.25 6.62 0.71 16.85 2.08 25.98 6.72 1.54

-3.5 0.72 0.46 0.01 0.13 0.06 0.26 6.64 0.69 15.88 2.16 25.26 6.38 1.52

-4.5 0.61 0.46 0.00 0.23 0.06 0.17 6.59 0.68 15.48 1.81 24.25 5.84 1.48

-0.5 < 63 μm 0.26 0.59 0.06 0.20 0.07 0.26 5.51 0.58 16.76 2.31 28.50 8.93 1.60

-1.5 0.22 0.55 0.03 0.27 0.08 0.17 5.20 0.52 16.66 2.49 30.99 8.86 1.65

-2.5 0.26 0.49 0.02 0.24 0.08 0.16 5.09 0.52 15.97 2.04 27.45 8.34 1.56

-3.5 0.28 0.48 0.01 0.17 0.08 0.22 5.95 0.51 15.28 1.56 25.91 9.01 1.56

-4.5 0.39 0.47 0.01 0.18 0.08 0.20 5.11 0.48 14.91 1.79 25.18 8.77 1.53

0.8 0.92 6.86 -0.5 All particles 0.64 0.06 0.27 0.07 0.25 6.70 0.74 16.92 2.44 23.90 7.08 1.49

0.8 0.91 6.71 -1.5 0.59 0.03 0.31 0.08 0.18 6.24 0.68 17.20 2.93 25.85 6.81 1.56

0.8 0.91 6.76 -2.5 0.51 0.01 0.21 0.07 0.23 6.22 0.66 16.62 2.07 26.37 7.14 1.54

0.8 0.91 6.50 -3.5 0.47 0.01 0.14 0.06 0.25 6.45 0.64 15.72 2.00 25.44 7.11 1.53

0.8 0.90 6.24 -4.5 0.46 0.01 0.21 0.06 0.18 6.01 0.60 15.26 1.80 24.61 6.98 1.50

-10 > 63 μm 0.66 0.53 0.02 0.09 0.05 0.37 6.63 0.86 19.00 1.83 28.86 6.81 1.78

-15 0.65 0.43 0.02 0.09 0.05 0.28 6.35 0.83 15.45 1.55 21.50 5.95 1.49

-20 0.62 0.43 0.02 0.08 0.05 0.29 6.36 0.85 16.02 1.23 24.44 5.69 1.50

-25 0.69 0.39 0.02 0.07 0.04 0.25 5.98 0.84 14.46 1.11 20.98 5.43 1.31

-30 0.68 0.34 0.02 0.04 0.04 0.24 6.39 0.89 11.76 0.80 18.32 4.42 1.07

-10 < 63 μm 0.34 0.48 0.03 0.10 0.06 0.29 4.61 0.59 14.75 1.52 27.67 7.79 1.51

-15 0.35 0.40 0.04 0.08 0.07 0.22 4.48 0.57 14.37 1.78 25.73 8.39 1.56

-20 0.38 0.40 0.02 0.06 0.05 0.26 4.53 0.60 16.27 1.04 32.82 8.08 1.72

-25 0.31 0.32 0.02 0.03 0.05 0.23 4.90 0.68 12.74 0.78 24.72 6.40 1.33

-30 0.32 0.46 0.02 0.03 0.04 0.36 4.35 0.62 11.34 0.61 24.21 6.10 1.20

0.8 6.12 -10 All particles 0.51 0.02 0.09 0.05 0.34 5.95 0.77 17.56 1.72 28.46 7.14 1.69

0.8 6.44 -15 0.42 0.02 0.09 0.06 0.25 5.69 0.74 15.07 1.63 22.99 6.81 1.51

0.8 6.44 -20 0.42 0.02 0.07 0.05 0.28 5.66 0.76 16.12 1.16 27.66 6.61 1.58

0.8 6.55 -25 0.37 0.02 0.06 0.05 0.25 5.64 0.79 13.92 1.00 22.15 5.73 1.31

0.8 6.66 -30 0.37 0.02 0.04 0.04 0.28 5.75 0.80 11.63 0.74 20.19 4.96 1.11
39

Water 

column 

depth, 

m

Water 

fraction 

of total 

weight of 

sediment

Sediment 

pH

Depth in 

sediment, 

cm

Particle 

size

Particle 

size, 

fraction 

of 

sample 

Total 

P mg 

g-1

DW

Loosely 

bound P 

mg g-1

DW

P bound 

to poorly 

crystalline 

Fe oxides 

mg g-1 DW

P 

extracted 

with 1M 

HCl mg 

g-1 DW

Residual 

P mg-1

DW

Percent 

carbon

Percent 

nitrogen

Total 

Fe mg 

g-1 DW

Fe in 

poorly 

crystalline 

Fe oxides

mg g-1 DW

Total 

Al mg 

g-1 DW

Total 

Ca mg 

g-1 DW

Total 

Ti mg 

g-1 DW

Site 26: Near stream to Agency Lake, North

-0.5 > 63 μm 0.72 0.66 0.03 0.33 0.05 0.25 7.08 0.70 14.78 2.25 21.28 5.62 1.33

-1.5 0.72 0.60 0.01 0.22 0.05 0.31 6.78 0.67 13.89 1.74 19.97 5.45 1.31

-2.5 0.74 0.49 0.01 0.20 0.06 0.23 6.80 0.65 14.27 1.58 19.15 5.56 1.34

-3.5 0.78 0.54 0.01 0.16 0.04 0.33 6.89 0.64 14.19 1.46 21.07 5.84 1.36

-4.5 0.74 0.51 0.01 0.17 0.05 0.28 6.70 0.62 14.59 1.67 20.79 5.52 1.36

-0.5 < 63 μm 0.28 0.57 0.03 0.29 0.05 0.20 5.64 0.54 14.64 2.07 23.83 6.87 1.36

-1.5 0.28 0.51 0.01 0.23 0.06 0.20 5.65 0.48 13.66 2.12 21.39 6.36 1.31

-2.5 0.26 0.48 0.01 0.17 0.04 0.27 5.50 0.44 13.15 1.24 21.46 6.05 1.26

-3.5 0.22 0.50 0.01 0.15 0.05 0.29 5.36 0.45 13.21 1.31 22.55 6.42 1.33

-4.5 0.26 0.52 0.00 0.15 0.05 0.32 5.56 0.43 13.39 1.32 24.91 7.59 1.39

0.9 0.92 6.93 -0.5 All particles 0.64 0.03 0.32 0.05 0.23 6.68 0.66 14.74 2.20 21.99 5.97 1.34

0.9 0.91 6.26 -1.5 0.57 0.01 0.23 0.05 0.28 6.46 0.62 13.83 1.85 20.38 5.71 1.31

0.9 0.91 6.28 -2.5 0.49 0.01 0.19 0.05 0.24 6.46 0.59 13.98 1.49 19.75 5.69 1.32

0.9 0.91 5.85 -3.5 0.53 0.01 0.16 0.04 0.32 6.56 0.60 13.98 1.42 21.39 5.97 1.36

0.9 0.90 5.76 -4.5 0.51 0.01 0.16 0.05 0.29 6.40 0.57 14.27 1.58 21.87 6.07 1.37

-10 > 63 μm 0.59 0.41 0.03 0.06 0.04 0.29 6.81 0.90 15.98 1.17 23.93 4.80 1.42

-15 0.58 0.26 0.03 0.07 0.04 0.12 5.70 0.78 14.36 0.92 22.99 4.43 1.31

-20 0.68 0.31 0.03 0.05 0.04 0.18 6.39 0.91 12.75 0.57 20.00 4.13 1.17

-25 0.58 0.44 0.02 0.06 0.05 0.31 6.63 0.97 10.82 0.72 17.78 3.66 0.97

-30 0.67 0.23 0.03 0.06 0.04 0.10 6.21 0.91 9.94 0.48 16.02 3.35 0.87

-10 < 63 μm 0.41 0.54 0.03 0.08 0.05 0.39 5.21 0.67 14.91 1.07 28.29 5.79 1.47

-15 0.42 0.34 0.03 0.04 0.04 0.23 4.98 0.66 13.35 0.77 25.88 5.33 1.34

-20 0.32 0.28 0.02 0.04 0.05 0.17 4.53 0.63 10.96 0.46 22.15 4.86 1.11

-25 0.42 0.27 0.02 0.04 0.04 0.17 4.77 0.68 9.35 0.58 18.55 3.92 0.90

-30 0.33 0.23 0.02 0.03 0.03 0.15 4.14 0.59 8.49 0.37 17.78 3.95 0.82

0.9 6.34 -10 All particles 0.47 0.03 0.07 0.04 0.33 6.16 0.81 15.54 1.13 25.70 5.20 1.44

0.9 6.47 -15 0.29 0.03 0.06 0.04 0.17 5.40 0.73 13.94 0.86 24.19 4.80 1.32

0.9 6.71 -20 0.30 0.03 0.05 0.05 0.18 5.80 0.82 12.19 0.53 20.68 4.37 1.15

0.9 6.55 -25 0.37 0.02 0.05 0.04 0.25 5.85 0.85 10.21 0.66 18.10 3.77 0.94

0.9 6.66 -30 0.23 0.03 0.05 0.04 0.12 5.53 0.81 9.46 0.45 16.60 3.55 0.85
48

Table 3. Names and locations of sampling sites where sediment cores were collected on October 24–26, 2006, 

from Upper Klamath Lake, Oregon.

Site Name Site ID

Latitude

(deg, min, sec)

Longitude

(deg, min, sec)

North of the city of Klamath Falls 1 42 15 54.97 -121 50 5.28

Buck Island 2 42 17 57.09 -121 50 20.09

Howard Bay (Wocus Bay) 3 42 19 51.99 -121 55 0.98

Mouth of Howard Bay, South 4 42 19 25.85 -121 52 48.26

Rattlesnake Point, South 5 42 19 42.82 -121 50 10.10

Mouth of Howard Bay, North (Squaw Point) 6 42 21 3.24 -121 52 41.68

West of Hanks Marsh 7 42 21 35.60 -121 50 5.62

Near Channel north west of Squaw Point 8 42 22 29.10 -121 53 22.09

Mid Lake 9 42 23 3.34 -121 51 20.39

Near Hagelstein Park 10 42 23 12.66 -121 49 13.79

Midway between Squaw Point and Eagle Ridge 11 42 23 28.90 -121 55 29.27

North of Mid Lake 12 42 24 19.63 -121 53 16.11

South of Modoc Point 13 42 24 34.93 -121 50 47.41

Ball Bay 14 42 24 15.53 -122 1 2.12

Shoalwater Bay 15 42 24 38.35 -121 57 50.05

South of Bare Island 16 42 24 47.23 -121 55 29.55

Modoc Point 17 42 26 1.77 -121 53 7.04

Mouth of Ball Bay 18 42 25 32.67 -122 1 3.63

Eagle Point 19 42 26 13.02 -121 58 15.15

North of Bare Island 20 42 26 5.72 -121 55 50.00

Midway between Modoc Point and the Williamson River 21 42 27 17.76 -121 54 13.51

Mid North 22 42 26 48.20 -122 0 20.42

Mouth of the Williamson River 23 42 27 22.86 -121 56 57.30

Mouth of Pelican Bay 24 42 27 7.94 -122 2 36.44

Near stream to Agency Lake, South 25 42 27 47.87 -121 59 15.94

Near stream to Agency Lake, North 26 42 28 29.80 -122 1 23.41
49

Table 4. Analytical reporting limits for bed sediments.

Constituent Analytical 

reporting limit

Aluminum 0.50%

Calcium 0.10%

Carbon 0.20%

Iron 0.50%

Nitrogen 0.40%

pH 0.1 pH units

Phosphorus 0.01%

Titanium 0.50%

Water content 1%