Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

CHARLOTTE HARBOR & ESTERO BAY 

AQUATIC PRESERVES 

WATER QUALITY STATUS & TRENDS FOR 1998- -2005 

Charlotte Harbor Estuaries 

Volunteer Water Quality Monitoring Network 

7 Year Results 

Final Report 

Prepared By: 

Renee Duffey* 

Raymond E. Leary 

Judy Ott 

Charlotte Harbor Aquatic Preserves 

12301 Burnt Store Road 

Punta Gorda, FL 33955 

*Currently at the Charlotte Harbor Environmental Center 

Submitted to: 

Catherine Corbett 

Charlotte Harbor National Estuary Program 

1926 Victoria Avenue 

Ft. Myers, FL 33901 

September 11, 2007 

CHAPs Technical Report #2 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

i 

Charlotte Harbor & Estero Bay Aquatic Preserves 

Water Quality Status & Trends for 1998 - 2005 

Charlotte Harbor Estuaries 

Volunteer Water Quality Monitoring Network 

7 Year Results 

Final Report September 11, 2007 

Florida Department of Environmental Protection 

Charlotte Harbor Aquatic Preserves Office 

Punta Gorda, FL 

In Cooperation with: 

Charlotte Harbor National Estuary Program 

Estero Bay Aquatic Preserves 

Charlotte Harbor Environmental Center 

Report Prepared by: 

Renee Duffey 

Raymond E. Leary 

Judy Ott 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

ii 

The Charlotte Harbor National Estuary Program is a partnership of citizens, elected 

officials, resource managers and commercial and recreational resource users working to 

improve the water quality and ecological integrity of the greater Charlotte Harbor 

watershed. A cooperative decision-making process is used within the Program to address 

diverse resource management concerns in the 4,400 square mile study area. Many of 

these partners also financially support the Program, which, in turn, affords the Program 

opportunities to fund projects such as this. The entities that have financially supported 

the Program include the following: 

U.S. Environmental Protection Agency 

Southwest Florida Water Management District 

South Florida Water Management District 

Florida Department of Environmental Protection 

Florida Coastal Zone Management Program 

Peace River/Manasota Regional Water Supply Authority 

Polk, Sarasota, Manatee, Lee, Charlotte, DeSoto, and Hardee Counties 

Cities of Sanibel, Cape Coral, Fort Myers, Punta Gorda, North Port, Venice, 

Fort Myers Beach, and Winter Haven 

and the Southwest Florida Regional Planning Council. 

The Southwest Florida Water Management District, on behalf of the Peace River and 

Manasota Basin Boards, provided funding for this project. 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

iii 

Charlotte Harbor Estuaries 

Volunteer Water Quality Monitoring Network Partners 

Supporting Partners 

Charlotte Harbor & Estero Bay Aquatic Preserves - Program Support 

Heather Stafford/Program Manager 

Charlotte Harbor National Estuary Program - Grant & Technical Support 

Lisa Beever/Program Director 

Catherine Corbett/Senior Scientist 

Florida Department of Environmental Protection Laboratories 

Jennifer Thera/South District Laboratory Chemist 

Dave Winkler/South District Laboratory Chemist 

FDEP Central District Laboratory 

Program Coordinator 

Judith Ott/Charlotte Harbor Aquatic Preserves 

Volunteer Coordinator

Melynda Schneider/Charlotte Harbor Aquatic Preserves 

Regional Coordinators

Bobbi Rodgers/Charlotte Harbor Environmental Center - Lemon Bay 

Melynda Schneider/Charlotte Harbor Aquatic Preserves - Charlotte Harbor 

Judy Ott/Charlotte Harbor Aquatic Preserves -Pine Island Sound & Matlacha 

Pass 

Stephanie Erickson/Estero Bay Aquatic Preserves - Estero Bay 

Technical Assistance

Terry Frohm, FDEP 

Jason Hale, CHEC 

Joe Hand, FDEP 

Joy Linn /Citizen - Data Entry 

Special Thanks

Betty Staugler, Charlotte County Sea Grant - Program Support 

Katie Fuhr, City of Naples Natural Resources - Program Support 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

iv 

Citizen Water Monitors

Judy Abbott Julie Drevenkar Jim Hummell Jack & Sue Nichol Linda Soderquist

Jan Alexander Rodney Duprey Jerry Jacobs Annette Nielson Stephanie Somsky

Brenda & Bruce Anderson Fran Dwyer Pat & Jack Jaquish Kyel Nolen Cathy Spencer

Bob Anderson Matt Edmunds Jennifer Jerrett Terry Novak Sandy Spry

Liz Armstrong Al Eleinko Steve Jess Judy & John Nyhus Bonnie & Harold St Marie

Penny, Christian & John Aspiolea Stephanie Erickson Mary & Doug Kastner Todd Ogle Heather Stafford

Annie Bacon Dan England Wilma Katz Kate Ohnemus Betty & James Staugler

Lind Ballen Josh Farnum Amy Kelb Peter Ordway Celia & Priscilla Stearns

Rick Bantz Karl Fedronas Martha & Ken Keller Judy Ott Carol & Doug Stewart

Zoe Bass Joan Fischer Kathy Kelly Sandy & Bob Palmer Cynthia Stinnett

Dave Bartlett Vicky & Joe Flemming Nancy Kilmartin Steve Park Rick Storsberg

Jan Barrett Jane Flynn Chic Kennedy Rosita Parker Crystal Suhr

Katie & Tom Bartholomew Trink Fletcher Gina Klotz Jerry Paul Ann & Howard Sunkin

Marc Becton June & Norm Franklin Eric Knight Walter Pavlovich Don Taggart

Sid and Paul Berger Greg Fretwell Brenda & Glenn Kraft Vicki Pettigrew Cecile & Bob Tatton

Charles Bettinson Norm & June Franklin Gene LaBelle Robin Petty Jack Taylor

Janet Betz Linda Frost K. LaCivita Shirley Phillips Al Teitler

Shirley Bluttaumueller Katie Fuhr Sherry LaFlamme Jim Pohmerr Marilyn Thompson

Brenda Bossman Sheri Funari Jay LaPore Tim Poole Sharon Traylor

Deb & Harold Brunner Nedra Garber Jo Lapinski Debbie Preston Ray Trozzo

Phil Buchanan Stephen Giguere Joy & Larry Linn Laura Pumis Frank Tuma

Chris and Kelly Burke Joe & Travis Gilpin Tina & Joe Linzalone Thomas Quiggle Cathy & Frank Valenti

Terry Cain BJ Givens Claudia & Richard Little J. Quigley Donna Venesky

Chan Carlson Ezell Givens Clayton Long Mary Rasley Kelly Victory

Cari Caudill Jim Glenn Jim Luccisano Chris Reed Faye Vidulich

Dan Ceilley Norm Gowan Margaret & Lloyd Lueptow Lenny Renda Ian Vincent

Barbara Chamberlin Christopher Gray Stephanie MacKenzie Harald Riehm Arlene Walters

Ed Chapin Mary Green Rhonda Mackenzie Rodger Roberts Mike Ward

Susan & Terry Clements Rita Greene Cindy & George Marks Rose & Glen Roberts Dick Wasserman

Kristie Coleman Jason Hale Helen Marshall Bobbi Rodgers Mike Weinberg

Marlyn Collom Robert Hamlin Lewis Matson Rodger Ruperts Margaret & Howard Wells

Kelly Connelly Chris & Tom Hansbierger Michael May Mike Ruggiero Henry Welter

Bill Cook Rebecca Harris Mary McAuliffe Tom Ruscik Ron Wesorick

Dan Corna Dan Harwell Mike McConnell Chuck Sayre Mark Westall

Lois & Ed Corson Mike Heare John Mcentaffer Mindy Schneider Dale Whitacre

Brian Cotterill Linda Hendrickson Pauline McIntosh Skip Schwartz Mary Whiteside

Sydney & Elizabeth Crampton Carol Hickler Glen McKee Mary Ann Scott Mary & Dave Wilcox

Paul Crowley Peter Hicks Bill McSharry Jackie Seeds Dianna & Gordon Willman

Michael Curran Debra Highsmith Carl Meyer Joan Sessions Dave Winkler

Carol Cutrone Harvey Hill Mickey Miller Brian Sieloff Tom Winter

Rusty Davidson Barbra Hiller Susan Mohr Jerri Silverman Sandy & Bill Workman

Bill Davis Rhonda Holtzclaw Charlotte Moore Ingrid & Pete Simke Jack Worthington

Connie & Dave December Jocelyn Honan Randy Mote Ted Sliwinski Scott Wouk

Jim Delzer Wyatt Hooks Al Moxon Logan & Gary Simmons Walt Wszolek

John DiPinto Debbie & Dave Horner Sandy & Jim Navarre Dare Smith Tom Zinneman

Barbara Dobbs Shirley, Cathy & Bud House Larry Newman Diane Smolen
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

v 

Executive Summary 

 This report presents water quality status and trends from the Charlotte Harbor 

Estuaries Volunteer Water Quality Monitoring Network (CHEVWQMN) from 1998 

through 2005 across the five Charlotte Harbor Aquatic Preserves (CHAPs) and the 

Estero Bay Aquatic Preserve (EBAP). Eleven water quality parameters were measured 

across forty eight sites grouped into nine estuary regions characterized by homogenous 

hydrologic conditions. These water quality parameters reflect and affect the health and 

sustainability of the Charlotte Harbor estuaries. 

 The Charlotte Harbor estuaries region extends from Venice south to Bonita 

Springs, encompassing 708 km2

 (175,000 acres) of productive submerged habitats. 

The six designated Florida Aquatic Preserves in the region include: Lemon Bay, 

Gasparilla Sound/Charlotte Harbor, Cape Haze, Pine Island Sound, Matlacha Pass and 

Estero Bay. These Aquatic Preserves are managed by the Florida Department of 

Environmental Protection (FDEP), CHAPs, and EBAP offices in Punta Gorda and Fort 

Myers Beach, respectively. 

 The CHEVWQMN was established in 1996 and is a partnership of the FDEP 

CHAPs, EBAP and South District Laboratory, Charlotte Harbor Environmental Center 

(CHEC), and the Charlotte Harbor National Estuary Program (CHNEP). The goal of the 

CHEVWQMN is to obtain consistent, technically sound, monthly water quality data from 

defined sites in the Aquatic Preserves and to direct resource management activities 

towards the most critical parameters, locations and trends. The water quality 

parameters evaluated include: dissolved oxygen, water clarity, salinity, nutrients, 

chlorophyll a, and fecal coliform bacteria. 

 To characterize water quality as it relates to estuarine health, CHEVWQMN results 

were compared both within the region and to other estuaries across the state of Florida. 

Additional comparisons were made to numerical criteria to aid in the interpretation of 

water quality results. A seasonal, nonparametric trend test was used to detect trends in 

water quality from 1998 through 2005 for each estuary region. Analyses of the 

relationships among selected water quality parameters were conducted to aid in the 

understanding of water quality conditions and trends across the region. Summaries of 

status and trend results for each parameter and estuary region are presented. 

 Across the Charlotte Harbor and Estero Bay Aquatic Preserves, CHEVWMQN 

results indicated generally average conditions compared to other Florida estuaries, 

although results varied seasonally, spatially and over time. Dissolved oxygen was 

typically lower than average compared to Florida’s estuaries, with frequent 

exceedances below Florida Surface Water Criteria of 4.0 and 5.0 mg/L. However, these 

criteria are currently under evaluation in order to take into account shallow estuarine 

water bodies with naturally low dissolved oxygen. Chlorophyll a median values were 

average to lower than average compared to Florida estuaries. However, annual means 

above the 11 μg/L Florida Impaired Waters Rule were observed at sites in Lemon Bay, 

Upper Charlotte Harbor and Pine Island Sound. Salinity median values were lowest in 

Upper Charlotte Harbor, Matlacha Pass and Upper Lemon Bay, indicating the strongest 

freshwater influences in the region. Upper Lemon Bay and Upper Charlotte Harbor also 

had the highest nutrient and bacteria concentrations within the region. Significant 

decreasing trends in salinity, turbidity, total Kjeldahl nitrogen and an increasing trend in 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

vi 

Executive Summary, cont. 

color were observed in many estuaries from 1998 through 2005. Significant 

relationships among light-limiting factors and water clarity, nutrients and phytoplankton, 

were also observed, although results varied across the nine estuary regions. 

Status and trends results presented in this report convey the spatial and temporal 

variability of water quality conditions across the Charlotte Harbor and Estero Bay 

Aquatic Preserves. CHEVWQMN results are used to characterize the relationships 

between water quality parameters and factors affecting estuarine health, including 

changes in freshwater inflows and influences from watershed land uses. The primary 

use of the dataset is to set resource management goals for the six Aquatic Preserves in 

order to preserve the health and sustainability of the system. The CHEVWQMN is a 

critical and cost effective program for understanding long term water quality trends and 

their causes within the region. Having a large volunteer program has the added benefit 

of promoting citizen support for the Aquatic Preserves resource management activities. 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

vii 

Table of Contents 

Section Page

I. Introduction......................................................................................................2-4 

II. Description of the Charlotte Harbor Estuaries Region.................................5-6 

III. Description of the Charlotte Harbor Estuaries Volunteer 

Water Quality Monitoring Network (CHEVWQMN)....................................... 7-8 

IV. Methods Used by the CHEVWQMN..............................................................9-24 

A. Introduction ................................................................................................ 9 

B. Study Design .........................................................................................9-11 

C. Quality Assurance Methods.................................................................... 12 

D. Field Methods........................................................................................... 13 

E. Laboratory Methods............................................................................14-15 

F. Data Preparation and Exploratory Analysis .....................................16-17 

G. Methods Used to Determine Water Quality Status...........................18-20 

1. Introduction........................................................................................ 18 

2. Comparisons of Water Quality within the CHEVWQMN .................... 18 

3. Comparison of CHEVWQMN Results to Typical Florida Water 

 Quality ..........................................................................................18-19 

4. Comparison to Regulatory Criteria ...............................................19-20 

H. Trend Analysis Methods.....................................................................21-23 

I. Methods in Determining Relationships between Water Quality 

 Parameters ............................................................................................... 24 

V. Water Quality Status and Trends Results for the CHEVWQMN from 1998- 

2005 .............................................................................................................25-80 

A. Introduction .........................................................................................25-27 

B. Secchi depth........................................................................................28-32 

1. Background ....................................................................................... 28 

2. Results .........................................................................................28-29 

3. Discussion ......................................................................................... 29 

C. Temperature ........................................................................................30-36 

1. Background ....................................................................................... 30 

2. Results .............................................................................................. 30 

D. Dissolved Oxygen...............................................................................37-42 

1. Background ....................................................................................... 37 

2. Results .........................................................................................37-38 

3. Discussion ....................................................................................38-39 

E. pH... .....................................................................................................43-47 

1. Background ....................................................................................... 43 

2. Results .........................................................................................43-44 

3. Discussion ......................................................................................... 44 

F. Salinity .................................................................................................48-52 

1. Background ....................................................................................... 48 

2. Results .........................................................................................48-49 

3. Discussion ......................................................................................... 49 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

viii 

Table of Contents, cont.

Section Page

G. Total Nitrogen......................................................................................53-57 

1. Background ....................................................................................... 53 

2. Results .........................................................................................53-54 

3. Discussion ....................................................................................54-55 

H. Total Phosphorus................................................................................58-61 

1. Background ....................................................................................... 58 

2. Results .........................................................................................58-59 

3. Discussion ......................................................................................... 59 

I. Chlorophyll a .......................................................................................62-67 

1. Background ....................................................................................... 62 

2. Results .........................................................................................62-63 

3. Discussion ....................................................................................63-64 

J. Fecal Coliform Bacteria ......................................................................68-69 

1. Background ....................................................................................... 68 

2. Results .........................................................................................68-69 

3. Discussion ......................................................................................... 69 

K. Turbidity...............................................................................................73-76 

1. Background ....................................................................................... 73 

2. Results .............................................................................................. 73 

3. Discussion ....................................................................................73-74 

L. Color.....................................................................................................77-80 

1. Background ....................................................................................... 77 

2. Results .............................................................................................. 77 

3. Discussion ....................................................................................77-78 

VI. Results of Water Quality Relationships within the CHEVWQMN.............81-98 

A. Introduction .............................................................................................. 81 

B. Relationship between Rainfall and Selected Parameters................82-83 

1. Background ....................................................................................... 82 

2. Results .............................................................................................. 82 

3. Discussion ......................................................................................... 83 

C. Relationship between Salinity and Selected Parameters ................84-88 

1. Background ....................................................................................... 84 

2. Results .........................................................................................84-85 

3. Discussion ......................................................................................... 85 

D. Nutrient and Chlorophyll a Relationships.........................................89-92 

1. Background ....................................................................................... 89 

2. Results .............................................................................................. 89 

3. Discussion ....................................................................................89-90 

E. Relationships between Light Limiting Parameters ..........................93-98 

1. Background ....................................................................................... 93 

2. Results .........................................................................................93-94 

3. Discussion ......................................................................................... 94 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

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Table of Contents, cont.

Section Page

VII. Summaries of Status and Trends Results for Each Aquatic Preserve .99-124 

A. Introduction .............................................................................................. 99 

B. Lemon Bay Aquatic Preserve.........................................................100-104 

1. Background ..................................................................................... 100 

2. Water Quality Status and Trends Results for Upper Lemon 

 Bay ...........................................................................................100-101 

3. Water Quality Status and Trends Results for Lower Lemon Bay..... 101 

4. Discussion ....................................................................................... 101 

C. Gasparilla Sound-Charlotte Harbor Aquatic Preserves...............105-111 

1. Background ..............................................................................105-106 

2. Water Quality Status and Trends Results for Upper Charlotte 

 Harbor ............................................................................................. 106 

3. Water Quality Status and Trends Results for Lower Charlotte 

 Harbor ......................................................................................106-107 

4. Water Quality Status and Trends Results for 

 Gasparilla/Cape Haze ..................................................................... 107 

5. Discussion ....................................................................................... 107 

D. Pine Island Sound and Matlacha Pass Aquatic Preserves..........112-116 

1. Background ..................................................................................... 112 

2. Water Quality Status and Trends Results for Pine Island Sound..... 113 

3. Water Quality Status and Trends Results for Matlacha Pass .......... 113 

4. Discussion ....................................................................................... 114 

E. San Carlos Bay................................................................................117-120 

1. Background ..................................................................................... 117 

2. Water Quality Status and Trends Results.................................117-118 

3. Discussion ....................................................................................... 118 

F. Estero Bay Aquatic Preserve .........................................................121-124 

1. Background ..................................................................................... 121 

2. Water Quality Status and Trends Results.................................121-122 

3. Discussion ....................................................................................... 122 

VIII. Conclusions .............................................................................................125-126 

IX. References ...............................................................................................127-132 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

x 

List of Figures and Tables in Text 

Section Page

I. Introduction 

Figure 1.1 CHEVWQMN sites and Aquatic Preserves of the Charlotte Harbor 

Region.......................................................................................................... 2

II. Description of the Charlotte Harbor Estuaries Region 

Figure 2.1: Aquatic Preserves & watersheds for the Charlotte Harbor 

region........................................................................................................... 4 

Table 2.1: ..Florida Aquatic Preserves within the Charlotte Harbor Estuaries 

Region.......................................................................................................... 5 

IV. Methods Used by the CHEVWQMN 

A. Introduction 

B. Study Design 

Figure 4.1: CHEVWQMN site map and estuary region delineation............ 10 

Table 4.1: CHEVWQMN site description and estuary region delineation... 11 

D. Field Methods 

Table 4.2: Field Method Summary ............................................................. 13 

E. Laboratory Methods 

Table 4.3: Laboratory Analysis Summary .................................................. 15 

Table 4.4: Summary of values reported as the minimum detection limit 

(MDL)......................................................................................................... 16 

G. Methods Used to Determine Water Quality Status 

Table 4.5: Percentile distributions and sample sizes for 'Typical Florida 

Estuarine Water Quality' (Hand 2004) used to interpret CHEVWQMN 

status ......................................................................................................... 19 

Table 4.6: Description of regulations used to determine water quality 

Status......................................................................................................... 20 

Table 4.7: Summary of values reported as the minimum detection limit 

(MDL) ........................................................................................................ 23 

Table 4.8: Summary of depth and Secchi depth results for each aquatic 

Preserve..................................................................................................... 23 

V. Water Quality Status and Trends Results from CHEVWQMN 

 A. Introduction 

 Table 5.1: Average annual rainfall (m) by watershed region ..................... 26 

 Figure 5.1: Average annual rainfall by watershed region .......................... 27 

B. Secchi Depth 

Table 5.2: Summary and status of Secchi depth (m) results for each 

Estuary....................................................................................................... 30 

Figure 5.2: Secchi depth (m) boxplot results for each estuary region ........ 30 

Figure 5.3: Seasonal Secchi depth (m) boxplot results for each estuary 

region ......................................................................................................... 31 

Figure 5.4: Time series plot of Secchi depth (m) for 1998 through 2005.... 32 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

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List of Figures and Tables in Text, cont.

Section Page

Table 5.3: Secchi depth (m) trend results .................................................. 32 

C. Temperature 

Table 5.4: Summary and status of temperature (°C) results for each estuary 

region ......................................................................................................... 34 

Figure 5.5: Temperature (°C) boxplot results for each estuary region........ 34 

Figure 5.6: Seasonal temperature (°C) boxplot results for each estuary 

region ......................................................................................................... 35 

Figure 5.7: Time series plot of temperature (°C) for 1998 through 2005.... 36 

Table 5.5: Temperature (°C) trend results.................................................. 36 

D. Dissolved Oxygen 

Table 5.6: Summary and status of dissolved oxygen (mg/L) results for each 

estuary ....................................................................................................... 39 

Table 5.7: Number and % of dissolved oxygen samples under 5 mg/L per 

Florida Surface Water Regulations ............................................................ 40 

Table 5.8: Number and % of dissolved oxygen samples under 4 mg/L per 

Florida Surface Water Regulations ............................................................ 40 

Figure 5.8: Dissolved oxygen (mg/L) boxplot results for each estuary 

region ......................................................................................................... 41 

Figure 5.9: Seasonal dissolved oxygen (mg/L) boxplot results for each 

estuary region ............................................................................................ 41 

Figure 5.10: Time series plot of dissolved oxygen (mg/L) for 1998 through 

2005 .......................................................................................................... 42 

Table 5.9: Dissolved oxygen (mg/L) trend results ...................................... 42 

E. pH 

Table 5.10: Summary and status of pH results for each estuary................ 45 

Figure 5.11: pH boxplot results for each estuary region............................. 46 

Figure 5.12: Seasonal pH boxplot results for each estuary region............. 46 

Figure 5.13: Time series plot of pH for 1998 through 2005 ........................ 47 

Table 5.11: pH trend results....................................................................... 47 

F. Salinity 

Table 5.12: Summary and status of salinity (ppt) results for each 

estuary ....................................................................................................... 50 

Figure 5.14: Salinity (ppt) boxplot results for each estuary region.............. 51 

Figure 5.15: Seasonal salinity (ppt) boxplot results for each estuary 

region ......................................................................................................... 51 

Figure 5.16: Time series plot of salinity (ppt) for 1998 through 2005 ......... 52 

Table 5.13: Salinity (ppt) trend results........................................................ 52 

G. Total Nitrogen 

Table 5.14: Percent of total nitrogen in organic form plus ammonia 

(TKN) ......................................................................................................... 54 

Table 5.15: Summary and status of total nitrogen (ppm) results for each 

estuary region ............................................................................................ 55 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

xii 

List of Figures and Tables in Text, cont.

Section Page

Figure 5.17: Total nitrogen (ppm) boxplot results for each estuary 

region ......................................................................................................... 56 

Figure 5.18: Seasonal total nitrogen (ppm) boxplot results for each estuary 

region ......................................................................................................... 56 

Figure 5.19: Time series plot of total nitrogen (ppm) for 1998 through 

2005 .......................................................................................................... 57 

Table 5.16: Total nitrogen (ppm) trend results ........................................... 57 

H. Phosphorus 

Table 5.17: Summary and status of phosphorus (ppm) results for each 

estuary ....................................................................................................... 59 

Figure 5.20: Phosphorus (ppm) boxplot results for each estuary region.... 60 

Figure 5.21: Seasonal phosphorus (ppm) boxplot results for each estuary 

region ......................................................................................................... 60 

Figure 5.22: Time series plot of phosphorus (ppm) for 1998 through 

2005 .......................................................................................................... 61 

Table 5.18: Phosphorus (ppm) trend results .............................................. 61 

I. Chlorophyll a 

Table 5.19: Summary and status of chlorophyll a (μg/L) results for each 

estuary region ............................................................................................ 64 

Table 5.20: Chlorophyll a annual means greater than 11 μg/l per Florida's 

Impaired Waters Rule ................................................................................ 64 

Figure 5.23: Chlorophyll a (μg/L) boxplot results for each estuary 

region ......................................................................................................... 65 

Figure 5.24: Seasonal chlorophyll a (μg/L) boxplot results for each estuary 

region ......................................................................................................... 65 

Figure 5.25: Time series plot of chlorophyll a (μg/L) for 1998 through 

2005 .......................................................................................................... 66 

Table 5.21: Chlorophyll a (μg/L) trend results ............................................ 66 

Table 5.22: Mann-Whitney between subjects results of chlorophyll a from 

1998-2001 compared to chlorophyll a from 2003-2005.............................. 67 

K. Fecal Coliform Bacteria 

Table 5.23: Summary and status of fecal coliform bacteria (cfu/100mL) 

results for each estuary region................................................................... 69 

Table 5.24: Fecal coliform exceedances per Florida Surface Water 

regulations for each estuary....................................................................... 70 

Figure 5.26: Fecal coliform bacteria (cfu/100mL) boxplot results for each 

estuary region ............................................................................................ 71 

Figure 5.27: Seasonal fecal coliform bacteria (cfu/100mL) boxplot results for 

each estuary region.................................................................................... 71 

Figure 5.28: Time series plot of fecal coliform bacteria (cfu/100mL) for 1998 

through 2005.............................................................................................. 72 

Table 5.25: Fecal coliform bacteria (cfu/100mL) trend results ................... 72 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

xiii 

List of Figures and Tables in Text, cont.

Section Page

L. Turbidity 

Table 5.26: Summary and status of turbidity (NTU) results for each 

estuary region ............................................................................................ 74 

Table 5.27: Sites with turbidity samples exceeding 29 NTU per Florida 

Surface Waters Criteria.............................................................................. 74 

Figure 5.29: Turbidity (NTU) boxplot results for each estuary region......... 75 

Figure 5.30: Seasonal turbidity (NTU) boxplot results for each estuary 

region ......................................................................................................... 75 

Figure 5.31: Time series plot of turbidity (NTU) for 1998 through 2005 ..... 76 

Table 5.28: Turbidity (NTU) trend results................................................... 76 

M. Color 

Table 5.29: Summary and status of color (PCU) results for each estuary 

region ......................................................................................................... 78 

Figure 5.32: Color (PCU) boxplot results for each estuary region.............. 79 

Figure 5.33: Seasonal color (PCU) boxplot results for each estuary 

region ......................................................................................................... 79 

Figure 5.34: Time series plot of color (PCU) for 1998 through 2005.......... 80 

Table 5.30: Color (PCU) trend results........................................................ 80 

VI. Water Quality Relationship Results from the CHEVWQMN 

A. Introduction 

B. Relationship between Rainfall and Selected Parameters 

C. Relationship between Salinity and Selected Parameters 

Figure 6.1: Scatterplot results of color as predicted by salinity .................. 86 

Figure 6.2: Scatterplot results of total phosphorus as predicted by 

salinity ........................................................................................................ 86 

Figure 6.3: Scatterplot results of total nitrogen as predicted by salinity...... 87 

Figure 6.4: Scatterplot results of turbidity as predicted by salinity.............. 87 

Figure 6.5: Scatterplot results of fecal coliform bacteria as predicted by 

salinity ........................................................................................................ 88 

D. Nutrient and Chlorophyll a Relationships 

Figure 6.6: Scatterplot results of chlorophyll a as predicted by total 

nitrogen ...................................................................................................... 91 

Figure 6.7: Scatterplot results of chlorophyll a as predicted by total 

phosphorus ................................................................................................ 91 

Table 6.1: Stepwise regression results of chlorophyll a as predicted by total 

nitrogen and total phosphorus.................................................................... 92 

E. Relationships between Light Limiting Parameters 

Figure 6.8: Scatterplot results of chlorophyll a as predicted by color ......... 95 

Figure 6.9: Scatterplot results of chlorophyll a as predicted by turbidity..... 95 

Figure 6.10: Scatterplot results of turbidity as predicted by color............... 96 

Figure 6.11: Scatterplot results of Secchi depth as predicted by color....... 96 

Figure 6.12: Scatterplot results of Secchi depth as predicted by turbidity.. 97 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

xiv 

Figure 6.13: Scatterplot results of Secchi depth as predicted by 

chlorophyll a............................................................................................... 97 

Table 6.2: Stepwise regression results of Secchi as predicted by color, 

turbidity and chlorophyll a .......................................................................... 98 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

xv 

List of Appendices 

Appendix A: Summary Statistics for Each Estuary and Site 

Appendix B: Water Quality Comparisons 

Appendix C: Comparison of Results to Numerical Water Quality Criteria 

Appendix D: Water Quality Relationships 

Appendix E: Rainfall Relationships 
Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

xvi 

List of Acronyms 

AMO: Atlantic Multidecadal Oscillation 

APHA: American Public Health Association 

CAMA: Coastal and Aquatic Managed Areas 

CCHMN: Coastal Charlotte Harbor Monitoring Network 

CFU: colony forming unit 

CHAPs: Charlotte Harbor Aquatic Preserves 

CHEC: Charlotte Harbor Environmental Center 

CHEVWQMN: Charlotte Harbor Estuaries Volunteer Water Quality Monitoring Network 

CHNEP: Charlotte Harbor National Estuary Program 

DO: Dissolved Oxygen 

EBAP: Estero Bay Aquatic Preserve 

ENSO: El Nino-Southern Oscillation 

FAC: Florida Administrative Code 

FDEP: Florida Department of Environmental Protection 

FGCU: Florida Gulf Coast University 

FWC: Florida Fish and Wildlife Conservation Commission 

FWS: Fish and Wildlife Service 

MDL: Minimum Detection Level 

NELAC: National Environmental Laboratory Accreditation Conference 

NOAA: National Oceanographic and Atmospheric Administration 

NOX: Nitrate plus nitrite 

NTU: Nephelometric units 

PCU: platinum cobalt units 

ppm: parts per million 

ppt: parts per thousand 

SFWMD: South Florida Water Management District 

SPSS: Statistical Package for Social Sciences 

STORET: Storage and Retrieval database 

SWFWMD: Southwest Florida Water Management District 

TMDL: Total Maximum Daily Load 

TN: Total Nitrogen 

TKN: Total Kjeldahl nitrogen 

TP: Total Phosphorus 

USACE: United States Army Corps of Engineers 

USEPA: United States Environmental Protection Agency 

USGS: United States Geological Survey 
Introduction CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

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Introduction CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

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Figure 1.1: CHEVWQMN sites and Aquatic Preserves of the Charlotte Harbor region.

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Gasparilla Sound-Charlotte Harbor 

Aquatic Preserve

Lemon Bay 

Aquatic Preserve

Cape Haze

Aquatic Preserve

Pine Island Sound

Aquatic Preserve

Matlacha Pass

Aquatic Preserve

Estero Bay 

Aquatic Preserve

0 6,100 12,200 18,300 24,400 3,050

Meters $&< CHEVWQMN Sites
Introduction CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

3 

Charlotte Harbor & Estero Bay Aquatic Preserves 

Water Quality Status & Trends for 1998 - 2005 

I. Introduction

The purpose of this report is to describe water quality conditions throughout the 

Charlotte Harbor estuaries region of southwest Florida. The Charlotte Harbor region 

includes six Florida Aquatic Preserves crossing eight interconnected estuary regions. 

Water quality data used in the analyses were collected by the Charlotte Harbor 

Estuaries Volunteer Water Quality Monitoring Network (CHEVWQMN) from 1998 

through 2005. 

 The Charlotte Harbor estuaries region extends from Venice south to Bonita 

Springs, encompassing over 700 km2

 (~175,000 acres) of diverse, productive 

submerged habitats (Fig. 1.1). North to south, the six designated Florida Aquatic 

Preserves include: Lemon Bay, Gasparilla Sound/Charlotte Harbor, Cape Haze, Pine 

Island Sound, Matlacha Pass and Estero Bay. 

 The legislative mission of the Aquatic Preserve Program is to preserve Florida's 

exceptional submerged resources in their natural condition for future generations to 

enjoy. The primary activities of the Aquatic Preserve Program are resource monitoring, 

resource management in the estuaries and watershed, and public education and 

outreach. The Aquatic Preserve Program is administered through the Florida 

Department of Environmental Protection (FDEP), Office of Coastal and Aquatic 

Managed Areas (CAMA). The local Aquatic Preserve offices include the Charlotte 

Harbor Aquatic Preserves (CHAPs) and the Estero Bay Aquatic Preserve (EBAP). 

 The CHEVWQMN conducts water quality monitoring throughout the region each 

month. The CHEVWQMN was established in 1996 as a partnership of the FDEP, 

CHAPs, the Charlotte Harbor Environmental Center (CHEC), and local citizens. Since 

1998, The Charlotte Harbor National Estuary Program (CHNEP), EBAP, and FDEP 

South District Laboratory have been active partners in supporting the CHEVWQMN. 

The monitoring program is administered through the CHAPs office in Punta Gorda, 

Florida. 

 The primary goal of the CHEVWQMN is to provide consistent, technically sound 

water quality data throughout the six Charlotte Harbor and Estero Bay Aquatic 

Preserves each month within a synoptic time period. These water quality data are used 

to guide effective estuary resource management by identifying the most critical water 

quality parameters, locations and trends within and throughout the region. The most 

critical water quality parameters are those that directly affect and reflect estuarine 

health, including: dissolved oxygen, water clarity, salinity, nutrients, chlorophyll a, and 

fecal coliform bacteria. 

 This report summarizes 1998 - 2005 water quality data throughout the Charlotte 

Harbor region and relates the findings to the general health of the individual estuaries. 

The analyses display water quality relationships both spatially and temporally as a 

means of highlighting regions and parameters of concern. The report comprises 

descriptions of the Charlotte Harbor estuaries regions (Section II), the CHEVWQMN 
Introduction CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

4 

(Section III), and the methods used (Section IV). The eight-year trends for each 

parameter are given in Section V, followed by relationships between the parameters in 

Section VI. Summaries of water quality and management considerations for each 

estuary are given in Section VII, followed by conclusions in Section VIII. Detailed tables 

of data analysis results are given in the appendices. 

Figure 2.1: Aquatic Preserves & watersheds for the Charlotte Harbor region. 
Description of the Charlotte Harbor Estuaries Region CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

5 

II. Description of the Charlotte Harbor Estuaries Region

 The Charlotte Harbor estuaries region (Figure 1.1), located in southwest Florida, is 

large, productive, complex and diverse. The Charlotte Harbor estuaries extend from 

Venice south to Bonita Springs, cross many political boundaries and encompass over 

700 km2 (~175,000 acres) of exceptional coastal and estuarine habitats. The greater 

Charlotte Harbor watershed is almost 10,000 km2 (~4,000 mi2) in size, ranking among 

the largest watersheds in Florida. The watershed, as defined by CHNEP, extends from 

the headwaters of the Peace River north of Bartow, Florida and the Franklin Locks on 

the Caloosahatchee River downstream to the Charlotte Harbor estuaries (Figure 2.1). 

 The Charlotte Harbor estuaries are located within the boundaries of many 

government agencies, research and educational institutions, non profit organizations 

and citizen groups. The estuaries cover parts of three counties, including Sarasota, 

Charlotte and Lee counties, as well as eight communities, including Englewood, Punta 

Gorda, Cape Coral, Fort Myers, Sanibel and Bonita Springs. The estuaries also include 

two Florida Department of Environmental Protection Districts (South and Southwest) 

and two Water Management Districts (South [SFWMD] and Southwest [SWFWMD]). 

There are six Florida Aquatic Preserves designated within the region: Lemon Bay, 

Gasparilla Sound/Charlotte Harbor, Cape Haze, Pine Island Sound, Matlacha Pass and 

Estero Bay. Additionally, the region is also part of the CHNEP and the National Wildlife 

Refuge System (Figure 1.1 and Table 2.1). 

To ensure the long term sustainability of the estuary resources and water quality, 

the Charlotte Harbor estuaries are cooperatively managed by a number of regional 

governmental and natural resource agencies. A strong partnership of organizations is 

critical to the long term management and sustainability of the natural resources and 

water quality of the Charlotte Harbor estuaries. These partners include county agencies 

(Lee, Charlotte, Hardee, DeSoto, Manatee and Sarasota), federal agencies (CHNEP, 

United States Environmental Protection Agency [USEPA], United States Geographical 

Survey [USGS], Fish and Wildlife Service [FWS], National Oceanographic and 

Atmospheric Administration [NOAA], United States Army Corps of Engineers [USACE]), 

and state agencies (FDEP, Florida Fish and Wildlife Conservation Commission [FWC], 

SFWMD, SWFWMD), along with research institutions such as Mote Marine Laboratory, 

educational institutions, such as Florida Gulf Coast University (FGCU), and non-profit 

organizations, such as the CHEC. These partnerships support the long term water 

Table 2.1: Florida Aquatic Preserves within the Charlotte Harbor Estuaries Region

Estuary Management Program

Lemon Bay Aquatic Preserve 1986 Sarasota,Charlotte 7,667

Gasparilla Sound/Charlotte Harbor Aquatic Preserve 1975 Charlotte, Lee 79,168

Cape Haze Aquatic Preserve 1978 Charlotte 11,284

Pine Island Sound Aquatic Preserve 1970 Lee 54,176

Matlacha Pass Aquatic Preserve 1972 Lee 12,511

Estero Bay Aquatic Preserve. 1966 Lee 9,834

Charlotte Harbor National Estuary Program 1995 Sarasota, Charlotte, Lee 173,000

Date Designated

Estuary Location 

(counties)

Estuary Area Managed 

(Acres)
Description of the Charlotte Harbor Estuaries Region CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

6 

quality monitoring of the CHEVWQMN. The CHEVWQMN is managed by the FDEP 

Charlotte Harbor Aquatic Preserve office in Punta Gorda, Florida. 

 The Charlotte Harbor region (Figure 1.1) includes eight interconnected estuaries, 

including (from north to south): Lemon Bay, Gasparilla Sound, Cape Haze, Charlotte 

Harbor, Pine Island Sound, Matlacha Pass, San Carlos Bay and Estero Bay. These 

estuaries are separated from the Gulf of Mexico by a chain of ten barrier islands from 

Manasota Key south to Little Hickory Island. Gulf of Mexico waters enter the estuarine 

complex through nine passes, from Stump Pass south to Big Hickory Pass. Estuary 

waters mix with freshwater inflows from three major rivers - Myakka, Peace and 

Caloosahatchee Rivers. In addition to the larger rivers, there are over 15 smaller 

tributaries from Alligator Creek in northern Lemon Bay, to the Imperial River in southern 

Estero Bay. The water exchange between these passes and tributaries creates a large 

variation in salinity and water quality conditions around the region by season and year. 

The unique physical and hydrological characteristics of each of these estuaries help 

sustain the complex habitats found throughout the region. 

 Many of the diverse submerged habitats of the Charlotte Harbor estuaries region 

include mangroves, salt marshes, tidal flats, seagrasses, and unvegetated submerged 

areas. The complex habitats support a vast food web, including invertebrates, shellfish, 

finfish, sharks, reptiles, birds and aquatic mammals. Endangered and threatened 

species also depend on the local estuary for food and shelter. The fragile balance 

between estuarine habitat and the health of these species depends largely on the water 

quality and factors affecting estuarine water conditions, including human uses of the 

system and watershed influences. 

 Humans interact with and influence the health of these coastal and estuarine 

habitats. Daily human interactions with estuarine species are important both 

commercially and recreationally. Commercial harvests of shrimp, clams, food fish and 

baitfish contribute significantly to the local economy. In 2004, nearly 4500 metric tons 

(~10 million lbs) of fish and shellfish were taken from the watershed (BEBR 2005). In 

addition, recreational fishing, boating, kayaking and nature watching are valuable 

pastimes that depend on the health of the estuary and its water quality. In 1993, 1.6 

million tourists visited the three counties located along the estuary (Sarasota, Charlotte, 

and Lee) and spent more than $1.1 billion dollars (Martin et al 1996). 

 Along with recreational and commercial uses of the estuary, water quality and 

quantity within the Charlotte Harbor estuaries depend on land uses and activities within 

the adjacent watersheds. The severity of the impacts of land use on water quality 

depends on both the intensity of the use as well as its proximity to surface water. Land 

uses in the Charlotte Harbor watershed include: rangeland, agriculture, mining, 

residential, commercial and industrial. The type and degree of land use and distance to 

the estuary vary for each sub-basin of the greater Charlotte Harbor watershed - from 

residential use near the small tributaries adjacent to Lemon and Estero Bays, to 

phosphate mining miles up the Peace River, to agricultural use in the upper watersheds. 

The watershed and rainfall/runoff conditions throughout the region strongly influence the 

downstream biological conditions of each estuary. 

 
Description of the CHEVWQMN CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

7 

III. Description of Charlotte Harbor Estuaries Volunteer Water 

Quality Monitoring Network

 The CHEVWQMN is a region-wide, fixed station, monthly water quality monitoring 

program. The CHEVWQMN is a partnership of the CHAPs, EBAP, CHEC, CHNEP, and 

local citizens. 

 The monitoring program was initiated in 1996 in response to aquatic preserve 

managers' needs for baseline resource information and citizens' concerns for the health 

of local estuaries. Originally, CHEC received a grant from the SWFWMD to start 

sampling ten sites in northern Charlotte Harbor for ten field parameters. In 1997 and 

subsequent years, the CHAPs received additional grants from the CHNEP to expand 

and maintain the monitoring program region-wide and increase the number of 

parameters to include laboratory analyses. 

 The primary purpose of the CHEVWQMN is to collect consistent, technically sound 

water quality data throughout the Charlotte Harbor estuaries region. Prior to the 

development of the CHEVWQMN, much of the water quality monitoring within the 

Charlotte Harbor region was limited to programs that occurred infrequently, were shortterm or covered only partial areas of the estuaries. Data resulting from these historical 

monitoring programs were challenging to integrate, analyze and use to identify critical 

resource concerns. 

 The CHEVWQMN was designed to characterize baseline water quality conditions 

throughout the region. The original design was developed by the CHAPs, with 

assistance from CHEC, the Three Creek Watch citizen group in Lemon Bay and the 

USEPA. The details of CHEVWQMN methods are described in the Comprehensive 

Quality Assurance Project Plan for the CHEVWQMN (FDEP, 1997) and summarized in 

Section IV of this report. The project plan was approved by the FDEP, CHNEP and 

USEPA. 

 The six specific objectives of the CHEVWQMN are: 

• Describe baseline water quality conditions throughout the six aquatic preserves 

• Identify the most critical, regional water quality locations, parameters and 

trends relative to estuarine health, fish and wildlife habitat, and human health 

• Complement other CHAP seagrass and regional water quality monitoring 

program results to define aquatic preserve resource management needs 

• Enhance community understanding and stewardship of the aquatic preserves 

• Improve aquatic preserves managers’ understanding of community concerns 

regarding local estuaries 

• Encourage the development of a partnership of agencies to conduct uniform 

water monitoring throughout the region. 

 To accomplish these objectives, the CHEVWQMN program follows a rigorous 

monitoring design. The sampling frequency provides a monthly synoptic snap-shot of 

water quality. CHEVWQMN citizen and agency water monitors are highly trained in the 

classroom and field, have standard sampling equipment and are generally assigned to 

work in pairs at a specific site. In addition, water monitors are required to attend regionwide quality assurance sampling practice sessions twice a year to receive updated 

supplies and equipment, validate techniques, and correct any problems that are 

identified. Each water monitor contributes over 35 hours a year, plus automobile and 
Description of the CHEVWQMN CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

8 

boat gasoline to the success of the CHEVWQMN. Without their support, this long-term, 

region-wide, water quality data would not be available to guide estuary resource 

management in the Charlotte Harbor estuaries. 

 Management and analysis of the CHEVWQMN data is conducted using Microsoft 

Access and Excel and Statistical Package for Social Sciences (SPSS) following specific 

data management criteria. The data are also entered into the federal water quality 

database (Storage and Retrieval database [STORET]) to allow access by other 

scientists and resource managers. 

 The on-going CHEVWQMN also provides baseline water quality data to other 

agencies, partners and citizen groups who request them. To date, the CHEVWQMN 

results have been used within the region to: 

• Identify Florida's impaired waters 

• Determine water quality and seagrass relationships 

• Establish resource based water quality targets 

• Establish resource management priorities and goals 

• Encourage and evaluate effectiveness of adaptive management practices; 

• Describe water quality conditions to the public 

• Evaluate the effects of biological and physical events, such as hurricanes and 

algal blooms, on estuary conditions 

• Allow citizens and agency staff to assess potential adverse resource impacts 

from proposed development projects 

 It is intended that the CHEVWQMN analyses of the data will be used to determine 

resource management objectives for each of the six Charlotte Harbor and Estero Bay 

Aquatic Preserves. 

 
Methods Used by the CHEVWQMN CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

9 

IV. Methods Used by the CHEVWQMN 

A. Introduction 

To provide consistent, technically sound water quality data, the CHEVWQMN 

follows rigorous monitoring protocols. The quality assurance, field and laboratory 

methods are described in detail in the Comprehensive Quality Assurance Project Plan 

for the CHEVWQMN (FDEP 1997, Updated 1999) and summarized here. The Quality 

Assurance Project Plan was approved by the FDEP, CHNEP and the USEPA. In 

addition, the stringent data preparation and analysis guidelines used by the 

CHEVWQMN to evaluate data results are also described below. These strong project 

management methods link the scientific and citizen monitoring communities by assuring 

the accuracy and precision of the data so they can be used confidently by resource 

managers and scientists. The approved methods also allow the CHEVWQMN data to 

be used to determine Florida Impaired Waters and to be entered into the federal 

STORET water quality data base, making them accessible nationwide. 

B. Sampling Design 

 Monthly sampling was made at 48 fixed sites that are widely distributed throughout 

the Charlotte Harbor estuaries region (Figure 4.1 and Table 4.1). The sites were 

chosen to represent general water quality conditions throughout the region, as well as to 

be accessible in a safe and timely manner for samples to be collected and transported 

to the laboratory within holding times. The sampling locations emphasize shallower, 

near shore coastal areas, with limited sampling in the deeper, open water portions of 

Charlotte Harbor. A result of this sampling bias of shallower waters is that water clarity 

values cannot be determined for shallow sites and times when clarity exceeds water 

depth. 

 At each site, during the monthly sampling time, surface water samples are 

collected and field measurements are made for ten physical and chemical parameters: 

wind speed and direction, wave height, tide stage, water depth, Secchi depth, water 

temperature, pH, dissolved oxygen and salinity. Water samples are collected for seven 

additional laboratory parameters: chlorophyll a, turbidity, color, total phosphorus, total 

Kjeldahl nitrogen, nitrate/nitrite, and fecal coliform bacteria. These are key water quality 

parameters needed to determine overall estuary health as it relates to seagrass, fish 

and wildlife needs. For quality assurance purposes, duplicate and blank laboratory 

parameters are collected each month at 10% of the sampling sites. Additional quality 

assurance measures are detailed in the next section. 

To assist with interpreting the results and identifying resource conditions for each 

estuary, sampling sites were grouped into nine estuary regions with similar hydrologic 

conditions (Table 4.2). These nine regions are based on13 hydrologic regions (strata) 

established by the CHNEP for the interagency Coastal Charlotte Harbor Monitoring 

Network (CCHMN). Four strata (Tidal Myakka River, Tidal Peace River, West Wall of 

Charlotte Harbor and East Wall of Charlotte Harbor), as defined by CCHMN, were 

grouped into the Upper Charlotte Harbor region for this study. The CCHMN strata were 
Methods Used by the CHEVWQMN CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

10 

designed to describe relatively homogeneous hydrologic regions based on the best 

available information and professional judgment of scientists throughout the Charlotte 

Harbor estuaries. Grouping the CHEVWQMN sites into the hydrologic strata allows the 

data to be compared to the CCHMN open water sampling results, the CHAPs seagrass 

monitoring results and to determine estuary specific resource management concerns 

and solutions. 

Figure 4.1: CHEVWQMN site map and estuary region delineation 

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EBV006

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte Harbor

Lower Charlotte Harbor

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Gasparilla/Cape Haze

SCV002

SCV001

PIJIM1

PIV007

PIV006

PIV004

PIV002

PIV001

MPV004

MPV003

MPV002

MPV001

LBV007

LBV006 LBV005

LBV004

LBV003

LBV002

LBV001

LBOYS1

LBGOT2

LBFOR1

GSV005

GSV003

GSV002

EBERS2

EBV007

EBV006

EBV005

EBV004

EBV003

EBV001

CHV013

CHV012

CHV011

CHV010

CHV009

CHV008

CHV007

CHV006

CHV005

CHV004

CHV003

CHV002

CHV001

0 6,100 12,200 18,300 24,400 3,050

Meters

&< CHEVWQMN Sites
Methods Used by the CHEVWQMN CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

11 

Table 4.1: CHEVWQMN site description and estuary region delineation

Estuary 

Region

 CHEVWQMN 

Site Station Name Start Date CCHMN Strata Aquatic Preserve # of Sites

LBFOR1 Forked Creek Apr-00 Outside Strata Lemon Bay 5

LBGOT2 Gottfried Creek Nov-98 Outside Strata Lemon Bay

LBV001 Alligator Creek Jul-98 Upper Lemon Bay Lemon Bay

LBV002 Lemon Bay Jul-98 Upper Lemon Bay Lemon Bay

LBV003 Lemon Bay Jul-98 Upper Lemon Bay Lemon Bay

GSV002 Gasparilla Sound Nov-97 Lower Lemon Bay Lemon Bay 7

LBANG1 Ainger Creek Sep-99 Lower Lemon Bay Lemon Bay

LBOYS1 Oyster Creek Feb-99 Lower Lemon Bay Lemon Bay

LBV004 Lemon Bay Jul-98 Lower Lemon Bay Lemon Bay

LBV005 Ski Alley Jul-98 Lower Lemon Bay Lemon Bay

LBV006 Buck Creek Jan-99 Lower Lemon Bay Lemon Bay

LBV007 Lemon Bay Sep-99 Lower Lemon Bay Lemon Bay

CHV001 Sunrise Waterway Nov-96 Tidal Peace Gasp. Sound/Charlotte Harbor 9

CHV002 Myakka River Nov-96 Tidal Myakka Gasp. Sound/Charlotte Harbor

CHV003 Sam Knight Creek Nov-96 Tidal Myakka Gasp. Sound/Charlotte Harbor

CHV004 Charlotte Harbor Nov-96 Tidal Peace Gasp. Sound/Charlotte Harbor

CHV005 Peace River Nov-96 Tidal Peace Gasp. Sound/Charlotte Harbor

CHV006 Charlotte Harbor Nov-96 Tidal Peace Gasp. Sound/Charlotte Harbor

CHV007 Ponce de Leon Inlet Nov-96 West Wall Gasp. Sound/Charlotte Harbor

CHV008 Alligator Creek Nov-96 Outside Strata Gasp. Sound/Charlotte Harbor

CHV013 Peace River Jul-01 Tidal Peace Gasp. Sound/Charlotte Harbor

CHV009 Burnt Store Entrance Feb-98 Lower Charlotte Harbor Gasp. Sound/Charlotte Harbor 3

CHV010 Charlotte Harbor Feb-98 Lower Charlotte Harbor Gasp. Sound/Charlotte Harbor

CHV011 Charlotte Harbor Feb-98 Lower Charlotte Harbor Gasp. Sound/Charlotte Harbor

CHV012 Bull Bay Jun-98 Cape Haze Cape Haze 4

GSV001 Coral Creek Nov-97 Cape Haze Gasp. Sound/Charlotte Harbor

GSV003 Gasparilla Sound Jan-98 Cape Haze Gasp. Sound/Charlotte Harbor

GSV004 Gasparilla Sound Jul-04 Cape Haze Gasp. Sound/Charlotte Harbor

PIJIM1 Big Jim Creek Jan-01 Pine Island Sound Pine Island Sound 6

PIV001 Pelican Bay Sep-99 Pine Island Sound Pine Island Sound

PIV002 Pine Island Sound Feb-98 Pine Island Sound Pine Island Sound

PIV004 Redfish Pass Jan-00 Pine Island Sound Pine Island Sound

PIV006 Pine Island Sound Feb-98 Pine Island Sound Pine Island Sound

PIV007 Pine Island Sound Jan-99 Pine Island Sound Pine Island Sound

MPV001 Matlacha Pass Feb-98 Matlacha Pass Matlacha Pass 3

MPV002 Matlacha Pass Feb-98 Matlacha Pass Matlacha Pass

MPV003 Matlacha Pass Feb-98 Matlacha Pass Matlacha Pass

EBV001 Matanzas Pass Mar-98 San Carlos Bay Estero Bay 4

MPV004 Matlacha Pass Feb-98 San Carlos Bay

SCV001 San Carlos Bay Feb-98 San Carlos Bay

SCV002 San Carlos Bay Feb-98 San Carlos Bay

EBERS2 Estero River Sep-01 Outside Strata Estero Bay 6

EBV003 Estero Bay Jun-98 Estero Bay Estero Bay

EBV004 Estero Bay Mar-98 Estero Bay Estero Bay

EBV005 Estero Bay Mar-98 Estero Bay Estero Bay

EBV006 Estero Bay Feb-00 Estero Bay Estero Bay

EBV007 Estero Bay Sep-01 Estero Bay Estero Bay

None GSV005 Coral Creek Jun-98 Lower Lemon Bay Lemon Bay 1

Estero Bay

Gasparilla/

Cape Haze

Pine Island 

Sound

Matlacha 

Pass

San Carlos 

Bay

Upper 

Lemon Bay

Lower 

Lemon Bay

Upper 

Charlotte 

Harbor

Lower 

Charlotte 

Harbor
Methods Used by the CHEVWQMN CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

12 

C. Quality Assurance Methods 

 

 Consistent with the CHEVWQMN Quality Assurance Project Plan, extensive 

measures are taken to ensure the precision and accuracy of the CHEVWQMN data by 

guiding field sample collection, laboratory analyses and data management. Specific 

quality assurance procedures include: 

• Classroom and field training are provided for each water monitor 

• Quality assurance practice sessions are required for all monitors 

• Uniform sampling equipment and up-to-date supplies are used at all sites 

• Sampling is conducted synoptically for all sites within one hour of sunrise on 

first Monday of each month 

• Specific water monitors and equipment are assigned to each site 

• Written field procedures and data sheets are used by all water monitors 

• Duplicate dissolved oxygen tests are conducted at each site each month 

• Duplicate and blank field samples are collected for laboratory analyzed 

parameters at 10% of sites each month 

• Samples are transported to the laboratory within maximum sample holding 

times 

• Chain-of-custody procedures are used to track samples 

• Laboratory analyses are conducted by FDEP and National Environmental 

Laboratory Accreditation Conference (NELAC) certified laboratories. 

Beginning in 2003, FDEP required NELAC certification and laboratories were 

given 18 months to comply. Prior to that date laboratory analyses were 

conducted following APHA Standard Methods which became the basis for 

NELAC protocols. 

• Replicate and blank laboratory analyses are conducted on 10% of samples 

each month 

• Data are reviewed by water monitors and staff for transcription errors 
Methods Used by the CHEVWQMN CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

13 

D. Field Methods 

 In compliance with the Quality Assurance Project Plan, written field procedures are 

followed by the water monitors. The procedures are described in detail in the 

CHEVWQMN Field Methods Manual (1998, updated 2005) and summarized in Table 

4.3. During monthly sampling, field measurements are made for ten parameters and 

water samples are collected for laboratory analyses of seven additional analytes from 

each of the 48 sites. CHEVWQMN field procedures used during monthly sampling 

events include: 

• Site specific equipment (cleaned according to instructions), updated supplies 

and the CHEVWQMN field methods manual and data sheet are used 

• Monitoring activities are started within one hour of sunrise 

• Sampling start, stop and sunrise times are recorded on the data sheet 

• Surface water "grab" samples are collected in clean, site specific sampling 

buckets 

• No bottom water samples are collected and no water column depth profiles are 

conducted 

• Weather and water conditions are recorded on the data sheet: wind speed and 

direction, cloud cover, wave height, and tide stage 

• Six physical and chemical parameters measured are in situ, including: water 

depth, water clarity (0.2 m Secchi and calibrated line), temperature (calibrated 

thermometer), pH (colorimetric test kit), dissolved oxygen (Winkler titration test 

kit) and salinity (based on specific gravity using a hydrometer) 

• Surface water samples are collected in clean sample bottles (pre-acidified as 

needed) for laboratory analysis of seven parameters, including: color, turbidity 

and chlorophyll a (brown polyethylene bottle), total phosphorus, total Kjeldahl 

nitrogen and nitrate plus nitrite (white Nalgene 500 ml bottle), and fecal coliform 

bacteria (sterile whirl pack) 

• Water samples are stored on ice and transported to the laboratory within the 

maximum holding times 

 

Table 4.2: Field Method Summary

Depth (m) Secchi depth (m) Temperature (deg C) DO (mg/l) pH Salinity (ppt)

Method weighted line

Secchi disk 

(LaMotte #0171) 

0.20 m disc 

calibrated at 0.10 m 

intervals

Armored thermometer 

(LaMotte #1066)

Winkler Titration Test 

Kit (LaMotte #7414)

Colorimetric test kit 

CresolRed (LaMotte 

#2111)

HACH #2234-00, 

Hydrometer 

(LaMotte #30025)

Comments

value missing when 

Secchi depth was 

equal to or greater 

than total depth immediate sample

average of two 

determinations immediate sample

determined by 

temperature and 

specific gravity
Methods Used by the CHEVWQMN CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

14 

E. Laboratory Methods

 Water samples collected by CHEVWQMN monitors require laboratory analysis for 

seven parameters using methods described in the Quality Assurance Project Plan and 

summarized in Table 4.3. All laboratories utilized by the CHEVWQMN are NELAC and 

state certified, except as noted in Section IV Part C, and use the following procedures to 

conduct the monthly analyses: 

• Duplicate and blank samples for laboratory parameters are collected in the field 

for 10% of the sites and analyzed in the laboratory. 

• Additional replicate and blank laboratory analyses are conducted for 10% of the 

samples. 

• Apparent color is measured in platinum cobalt units (PCU) and determined by 

visual comparison without filtration using the platinum cobalt method (APHA 

2120B and USEPA 110.2). 

• Turbidity is measured in Nephelometric units (NTU) using the Nephelometric 

method and is estimated by comparing the amount of light scattered through 

the sample to a reference standard under the same conditions (APHA 2130 B 

and USEPA 180.1). 

• Chlorophyll a is measured in μg/L and determined spectrophotometrically 

without pheophytin correction (APHA SM10200 H). Due to time and funding 

constraints, chlorophyll a analyses were not conducted from December 2001 

through December 2002. 

• Total phosphorus samples are preserved with acid in the field, then measured 

in mg/l as the combination of orthophosphate, condensed phosphates and 

organically bound phosphates (USEPA 365.4 and APHA 4500 P-E). 

• Total Kjeldahl nitrogen samples are preserved with acid in the field, then 

measured in mg/L as the sum of organic nitrogen and ammonia (USEPA 351.2 

and APHA 4500-Norg B). 

• Nitrate and nitrite samples are preserved in the field with acid, then measured 

collectively in mg/L (USEPA 353.2 and APHA 4500-NO3 B). 

• Total nitrogen is calculated as the sum of total Kjeldahl nitrogen and nitrate plus 

nitrite values. 

• Fecal coliform bacteria value is measured as colony forming units (cfu) per 100 

ml and derived from counts of colony forming units per 100 mL aliquot 

incubated for 24 hours in an elevated temperature environment (APHA 9222 

D).
Methods Used by the CHEVWQMN CH

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

15 

Table 4.3: Laboratory Analysis Summary

Lab* Method Lab* Method Lab* Method 

Total Kjeldahl Nitrogen (ppm) DEP South1 USEPA 351.2 Cape Coral2 APHA 4500-NOR(B) Tri-Tech3 USEPA 351.2 De

Nitrate plus Nitrite (ppm) DEP South1 USEPA 353.2 Cape Coral2 APHA 4500-NO3(B) Tri-Tech3 USEPA 353.2 DePhosphorus (ppm) DEP South1 USEPA 365.4 Cape Coral2 APHA 4500 P-E Tri-Tech3 USEPA 365.4 DeChlorophyll a (μg/l) DEP South1 APHA 10-2000-H Cape Coral2 APHA 10-2000-H Tri-Tech3 APHA 10-2000-H DE

Fecal Coliform (cfu/100ml) DEP South1 APHA 9222 D Cape Coral2 APHA 9222 D Tri-Tech3 APHA 9222 D DETurbidity(NTU) DEP South1 USEPA 180.1 Cape Coral2 APHA 2130 B Tri-Tech3 USEPA 180.1 DE

Color (PCU) DEP South1 APHA 2120 B Cape Coral2 APHA 2120 B Tri-Tech3 APHA 2120 B DE

1Florida Department of Environmental Protection South District Laboratory, 28000 A-10 Airport Road Punta Gorda, FL 33982 2City of Cape Coral Laboratory, 3310 SW 20th Avenue Cape Coral, FL 339143Tri-Tech Laboratories, 7240 Old Cheney Hwy Orlando, FL 32807 4Florida Department of Environmental Protection Central District Laboratory, 2600 Blair Stone Road Tallahassee, FL 32399 

11/98-9/01 11/01-12/02 2/02-12/03 
Methods Used by the CHEVWQMN CHEVWQMN Report 2007 

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16 

F. Data Preparation and Exploratory Analysis 

After field sampling and laboratory analyses have been completed according to 

quality assurance procedures, CHEVWQMN data are entered into a database. For this 

report, data were compiled for the eight-year period from 1998 to 2005 and for each 

designated rainy and dry season. The dry seasons were defined as the months of 

November through May and the rainy seasons were June through October 

(Montgomery 2005). Average annual rainfall data were collected for the region using 

DBHYDRO from SFWMD (2007) and from the USGS Drainage Basin Total Summaries 

provided by SWFWMD (2007). Data preparation and exploratory analyses were 

conducted to: 1) screen for errors 2) determine the suitability for statistical applications 

and 3) group sites into estuary regions for further analysis. Data preparation, storage 

and analysis of results were conducted using SPSS and Microsoft Access and Excel. 

 Once the compiled dataset was screened for errors and outliers, results were 

deemed invalid and not used for analysis if they met at least one of two conditions: 1) 

were outside the minimum and maximum detection limits for laboratory or field methods, 

2) were values not possible to occur under natural conditions for each parameter and 

site. After the data were screened for outliers, accommodations were made for values 

reported as the minimum detection limits (MDLs) for each parameter. It is recognized 

that the true values fall somewhere between the MDL and 0. Therefore, to characterize 

values below laboratory detection limits for nutrients, chlorophyll a and turbidity, all 

values reported as the MDL for these parameters were divided by 2 and the adjusted 

values were used in these analyses. Similarly, apparent color values reported as the 

MDL were adjusted to 1 PCU and fecal coliform bacteria MDL values were adjusted to 1 

cfu/100 mL. A summary of MDLs for each parameter and laboratory for the study 

period are included in Table 4.4. 

 

 After the dataset was prepared, the distribution of the data was assessed to 

determine the need to use parametric or nonparametric statistical methods. Visual 

assessment of histograms and quantitative assessment of skewness were conducted. 

Similar to patterns found in other typical water quality datasets, multiple sampling levels 

(by estuary region, season, year etc.) exhibited non-normal distributions. Because the 

data were not normally distributed and there were large outlying values, nonparametric 

statistics were used to make comparisons between groups, quantify relationships 

between variables, and estimate trends. In general, nonparametric tests are less 

affected by outlying values, normal distribution violations, and minimal censoring of 

laboratory results. 

 Following adjustments to the MDLs and evaluation of data distribution, the 

CHEVWQMN sampling sites were grouped into nine estuary regions for data analysis. 

Parameter TKN (ppm) NOX (ppm) TP (ppm) ChlA (μg/L) Coliform (cfu/100mL) Turbidity (NTU) Color (PCU)

Minimum MDL 0.080 0.004 0.004 0.03 1 0.02 1

Maximum MDL 0.500 0.100 0.050 2.00 2 1.40 5

Table 4.4: Summary of values reported as the minimum detection limit (MDL)
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The purpose of grouping the CHEVWQMN sites by estuary region was to facilitate 

interpretation of the water quality results so that estuary specific resource conditions 

and management needs could be determined. The nine estuary regions represent 

areas of relatively uniform hydrologic conditions based upon the 13 hydrologic strata 

defined by the interagency CCHMN established by the CHNEP. The CCHMN 

hydrologic strata were developed using the best available information and professional 

judgment of scientists throughout the Charlotte Harbor estuaries. In Northern Charlotte 

Harbor, four CCHMN strata (Tidal Myakka River, Tidal Peace River, West Wall of 

Charlotte Harbor and East Wall of Charlotte Harbor) were grouped together and are 

referred to in this report as the Upper Charlotte Harbor estuary region. The nine estuary 

regions used for this report were chosen to most accurately represent spatial 

relationships between biological and physical parameters and watershed influences for 

each estuary, as well as reflect resource management jurisdictions for each aquatic 

preserve. 

 To characterize homogeneity of site conditions within each estuary region and 

reinforce estuary region delineations, an exploratory k-means cluster analysis was 

conducted using SPSS. Sites in the Upper Charlotte Harbor region were grouped to 

maximize sample size and characterize variability in that region. The nine estuary 

regions include sites from six aquatic preserves as shown in Table 4.1 and Figure 4.1. 
Methods Used by the CHEVWQMN CHEVWQMN Report 2007 

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G. Methods Used to Determine Water Quality Status

1. Introduction 

 

 The status of water quality parameters across the study region was evaluated to 

guide interpretation of water quality as it relates to estuary health. Water quality status 

was evaluated by comparing results between regions within the CHEVWQMN program 

as well as comparing results to additional estuarine baseline datasets and regulatory 

criteria. Summary statistics are provided for each estuary region including sample size 

(N) minimum, maximum, mean, standard error (SE) and median. Standard error is a 

measure of spread within the data and is the standard deviation divided by the sample 

size. Estuary medians were also ranked in ascending order to demonstrate the relative 

relationships between estuaries for a given parameter. Estuary results are compared to 

water quality classifications as described below and displayed in tables by parameter in 

the Results section. 

2. Comparisons of Water Quality Conditions within the Charlotte Harbor 

Estuaries 

 The first method, used to describe regional water quality status based on 

CHEVWQMN results, quantified the relationship between regions and seasons for each 

parameter. To estimate differences across all estuary regions within the entire region 

the Kruskal-Wallis test was used. The Kruskal-Wallis test is a nonparametric one-way 

between-subjects analysis of variance (ANOVA) which compares differences between 

two or more groups. To quantify differences between individual estuaries, a post hoc 

comparison was conducted using the Mann-Whitney U test. The Mann-Whitney U test 

is a nonparametric version of the between-subjects t-test which compares differences 

between medians of two groups. The Mann-Whitney U test was also used to detect 

significant differences between the rainy and dry season for each estuary region. Box 

plots are provided for a visual analysis of seasonal and regional comparisons. Each 

box represents the upper and lower quartiles with the median value given within each 

box. Box plot data tables are provided in the following sections with detailed results 

included in Appendix B. 

3. Comparison of Water Quality Conditions in the Charlotte Harbor Region to 

Typical Florida Estuaries 

 As a second guide to interpreting estuary health relative to water quality 

conditions, CHEVWQMN results were compared to estuaries across the state. To 

interpret CHEVWQMN results relative to Florida estuaries, results for each estuary and 

site were compared to baseline water quality conditions for over 20 estuaries around the 

state. The publication Typical Water Quality Values for Florida’s Lakes, Streams, and 

Estuaries (Hand 2004) was chosen as the source of baseline comparison. The 

publication was chosen because of the large number of samples (over 20,000), 

consistent sampling period (1990 - 2003), and complete set of parameters. Because of 

its uniform, continuous and reliable dataset, Typical Water Quality Values for Florida’s 

Lakes, Streams, and Estuaries appears to be the most representative source of estuary 
Methods Used by the CHEVWQMN CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

19 

conditions across the state. However, it should be emphasized that the data contained 

within Typical Water Quality values for Florida’s Lakes, Streams, and Estuaries

represent two climactic regions and five biogeographic regions. See Table 4.5 for a 

brief description of the length of the dataset and sample sizes. 

 To characterize the water quality in the Charlotte Harbor estuaries, median values 

for each parameter were compared to percentile distributions compiled from Typical 

Water Quality Values for Florida’s Lakes, Streams, and Estuaries (Hand 2004). To 

facilitate the use of statewide, water quality values for estimating estuary health, the 

percentile distributions were grouped to represent above average, average and below 

average estuary health conditions. The percentiles were grouped based on values used 

in Florida’s Trophic State Indices to describe general health categories for Florida’s 

lakes, streams and estuaries. For this report, the following percentile categories were 

used to interpret CHEVWQMN results: below average =10 through 30, average = 31 

through 69, and above average = 70 and greater. Resulting percentile categories for 

each estuary are included in tables in the Results section. Site specific results and 

percentiles are included Appendix A. 

4. Comparison to Regulatory Criteria 

 The third method used to describe the status of Charlotte Harbor water quality 

conditions compared CHEVWQMN results to available Florida water quality criteria and 

standards. Florida Surface Water Regulations (Chapter 62-302.530, Florida 

Administrative Code [FAC]) and Impaired Waters Rule (Chapter 62-303.353, FAC) 

served as comparison sources for dissolved oxygen, chlorophyll a, turbidity, and fecal 

coliform bacteria. For some CHEVWQMN parameters, estuaries and sites, insufficient 

numbers of samples were available to allow for direct comparison of the results to a 

specific regulation. Where insufficient data were available, general comparisons were 

made to the numerical water quality criterion. Comparisons are included in the Results 

section of this report for each parameter. This analysis is a tool for quantifying water 

quality status and in no means represents methods, findings or decisions resulting from 

the Florida’s Impaired Waters and Total Maximum Daily Load Programs. Regulatory 

criteria are summarized in Table 4.6. 

Table 4.5: Percentile dsitributions and sample sizes for 'Typical Florida Estuarine Water Quality' (Hand 2004) used to interpret CHEVWQMN status

Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) (cfu/100ml) (NTU) (PCU)

10 0.0875 10.6 4 7.43 6.6 0.19 0.01 1.5 1 0.87 5

20 0.5 16.38 5.01 7.62 13.7 0.32 0.023 2.7 1 1.4 7

30 0.7 18.9 5.62 7.75 17.8 0.44 0.048 3.8 1 1.9 10

40 0.9 21 6.1 7.83 21.1 0.55 0.069 5 2 2.4 14

50 1 23 6.5 7.9 23.8 0.67 0.096 6.13 5 3.1 20

60 1.2 25.1 6.9 8 26.1 0.79 0.12 7.842 8 4.1 25

70 1.35 27.2 7.31 8.07 28.2 0.93 0.16 10.1 17 5.8 36

80 1.6 28.8 7.88 8.15 30.5 1.1 0.22 13.4 33 8.9 55

90 2.1 30 8.67 8.3 32.9 1.39 0.33 20.2 80 15.6 100

75,987 392,487 321,526 346,718 331,440 20,410 58,587 68,144 168,532 250,890 41,556

below average 

(<30)

average 

(30<, >60)

above average 

(>60)

# observations
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Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

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Table 4.6: Description of regulations used to determine water quality status

Source Description Parameter Criteria Summary

Impaired Waters Rule 

62-303.353 Chlorophyll a

Annual mean must not exceed 11 ug/l or not have increased by more 

than 50% in two or more consecutive years

Fecal Coliform Monthly average must not exceed 200 cfu/100ml

10% of samples must not exceed 400 cfu/100ml

Must not exceed 800 cfu/100mL on any given day

DO Daily average must be greater than 5 mg/l and never less than 4 mg/l

Turbidity Must not exceed 29 NTU or above natural background conditions

Florida Surface Water 

Regulations 62-302.530 

Class III Fresh and Marine
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H. Analysis Methods Used to Determine Trends 

 To quantify changes in water quality over time for each estuary, the seasonal 

Kendall trend test was used. The seasonal Kendall trend test is commonly used for 

trend analysis of water quality conditions to accommodate seasonal distribution of 

values. In addition, the nonparametric test is used for its robustness to deviations from 

a normal distribution and outlying values. In addition, the test is somewhat robust to 

censored values and missing data within the series. The seasonal Kendall trend test is 

a modification of the Mann-Kendall test that adjusts for seasonality across the time 

series. The test, developed by Hirsch, Slack and Smith in 1982, has evolved 

extensively over the years to account for serial correlation, spatial variation across sites 

and various anomalies within the dataset (e.g. Hirsch, Slack and Smith 1982; Hirsch 

and Slack 1984; Hirsch, Alexander and Smith 1991; Helsel and Hirsch 2002). 

 The seasonal Kendall trend test ranks the differences between seasonal data 

pairs to calculate the test statistic and variance which produces the correlation 

coefficient tau and respective significance value. For this report, a season was defined 

as one month. The test statistic (S) is the sum of differences between all months across 

the series, in which January is only compared to January, February to February, etc, for 

the study period. The test statistic is then standardized and divided by the standard 

deviation to estimate the correlation coefficient and two tailed significance value. When 

a significant trend (p<0.05) is detected, the slope of the trend line is estimated. The 

trend slope is the median of all slopes of the monthly data pairs used to estimate the 

initial test statistic (S). . 

 For trend analysis of the CHEVWQMN data, the seasonal Kendall trend test was 

conducted using the USGS, “Computer Program for the Kendall Family of Trend Tests”. 

The USGS program was created and interpreted by Dennis R. Helsel, David K. Mueller, 

and James R. Slack (2006). The package is a Microsoft DOS based program which 

produces the seasonal Kendall trend test statistic, standard normal deviate, significance 

value and trend equation. For this report, a "water year" includes the months of October 

through September. 

 Interpreting the results of the seasonal Kendall trend test is limited by the amount 

of censoring of laboratory results, study duration and underlying patterns in the data. 

These conditions may increase the possibility of Type I or Type II errors in the results. 

Prediction of the significance value of a trend depends on the absence of serial 

correlation in the time series (Helsel and Hirsch 2002). Serial correlation (or 

autocorrelation) is defined as the degree to which the previous result influences the 

subsequent result. Autocorrelation can exist both intra-annually as a seasonal type 

affect, and inter-annually as serial correlation across the time series. When 

autocorrelation does exist, it is necessary to adjust the series for seasonal or interannual effects. To accurately determine autocorrelation, as a means to adjust the 

significance value of the trend, the dataset must contain at least ten years of data 

(Helsel and Hirsch 2002). Because only eight years (seven complete water years plus 

two incomplete water years) of CHEVWQMN data were analyzed in this study, 

autocorrelation could not be accurately quantified either seasonally or across the full 

time series. Therefore, it is important to note that autocorrelation may exist within the 

time series, affecting the overall trend significance. Because some autocorrelation may 
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Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

22 

exist, the results are presented in this report as a preliminary indicator of possible water 

quality trends, which will be reevaluated following collection of three more years of data. 

 Two additional considerations for interpreting trends in the CHEVWQMN results 

are the frequency of laboratory results reported as the MDL and the percent of Secchi 

depths observed as greater than total depth. The seasonal Kendall trend test is robust 

to censoring of data only if the MDLs do not change during the study. In this study, the 

MDL changed frequently for all laboratory parameters, primarily as a function of 

changes in laboratories conducting the analyses. Therefore, for trend analyses only, 

within this report all values reported as MDL were set equal to the highest MDL reported 

for each parameter during the eight-year study duration. In addition, trend analyses 

were not conducted on parameters where greater than 50% of the data as reported was 

the MDL. These conditions are summarized in Table 4.7. 

 A similar method for qualifying Secchi depth for trend analysis was conducted. 

Frequent observations, in which Secchi depth exceeds total depth, artificially influence 

trend results. As a result, trend analysis was not conducted when Secchi depth was 

equal to or greater than bottom depth for over 50% of the samples for each estuary. 

See Table 4.8. 

 Monthly results for each site were aggregated by estuary region to determine the 

median value by parameter for each month. All estuaries had a minimum of 60 samples 

over the complete time series for each parameter. Trend outputs include: results 

summary table, time series plots per parameter over the complete time series and 

monthly box plots. The monthly box plots visually display seasonal relationships and 

the time series plots provide a visual reference for long-term trends within the series. 

 The seasonal Kendall trend test was not conducted for chlorophyll a in response to 

12 months of missing data in 2002 due to funding constraints and changes in lab 

methods. To estimate changes in chlorophyll a from 1998 through 2005 the MannWhitney U test was used. The Mann-Whitney U test is a nonparametric version of the 

between-subjects t-test which compares differences between medians of two groups. 

The collective chlorophyll a results from 1998 through 2001 were compared to the 

collective results from 2002 through 2005 for each estuary region. 

Table 4.7: Summary of values reported as equal to the maximum MDL

% Reported as 

MDL**

Minimum 

MDL

Maximum 

MDL Trend Threshold

Ttotal Nitrogen* (ppm) na na na na

Total Kjeldahl Nitrogen (ppm) 22% 0.080 0.500 0.500

Nitrate + Nitrite (ppm) 93% 0.004 0.100 na

Phosphorus (ppm) 22% 0.004 0.050 0.050

Chlorophyll a (μg/l) 20% 0.030 2.000 2.000

Fecal Coliform (cfu/100ml) 34% 1 2 2

Turbidity (NTU) 15% 0.02 1.40 1.40

Color (PCU) 6.5 1 5 5

*Total nitrogen is the calculated sum of total Kjeldahl nitrogen and nitrate plus nitrite

**Values in bold do not qualify for trend analysis due to > 50% of values are reported as the MDL
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Table 4.8: Summary of depth and secchi depth results for each aquatic preserve

average sample 

depth (m)

average secchi 

depth (m)

total sample 

results

total valid 

cases

total greater 

than bottom

% greater 

than bottom*

Upper Lemon Bay 1.0 0.9 378 161 217 57%

Lower Lemon Bay 1.4 1.3 525 230 295 56%

Upper Charlotte 1.5 0.9 653 394 259 40%

Lower Charlotte 2.1 1.8 248 105 143 58%

Gasparilla/Cape Haze 1.6 1.5 195 86 109 56%

Pine Island Sound 1.7 1.4 379 167 212 56%

Matlacha Pass 3.2 1.6 257 202 55 21%

San Carlos Bay 3.7 1.5 330 327 3 1%

Estero Bay 1.2 1.2 348 177 171 49%

All Sites 1.8 1.3 3313 1849 1464 44%

**values in bold are greater than 50% and not used for trend analysis
Methods Used by the CHEVWQMN CHEVWQMN Report 2007 

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24 

I. Methods Used to Determine Relationships between Water Quality 

Parameters 

 An additional analysis was conducted to describe the relationships between water 

quality variables for each estuary collectively and for each season. Relationships 

between water quality variables were quantified using both the Spearman’s rho 

correlation test and stepwise linear regressions. Spearman’s rho is a nonparametric 

correlation analysis that characterizes relationships using ordered ranking of results. 

Reported statistics include sample size, significance value and Spearman’s correlation 

coefficient. Spearman’s rho correlation coefficient describes the strength and direction 

of the relationship ranging from -1 to 1, where -1 indicates a strong negative 

relationship, +1 indicates a strong positive relationship and 0 indicates no relationship. 

Evaluation of relationships was conducted on selected parameters for the entire study 

region and for each estuary. Results are included in tables and scatter plots in Section 

VI and Appendix D. 

 As a means of describing estuarine health and water clarity for seagrass growth, 

forward stepwise regression analyses were conducted to quantify contributions of 

selected parameters to changes in Secchi depth and chlorophyll a values. A stepwise 

regression differs from a linear regression in that only parameters that contribute 

significantly to changes in the dependent variable are added to the regression equation. 

Addition of parameters into the regression model was set at p<0.05 and parameters 

were removed from the regression when p>0.10. Statistics reported include: F, R, R2

, 

R2 adjusted, R2 change, and SE. R2 describes the percent of variability in the dependent 

variable that is described for the given parameter. R2 values range from 0 to 1, with 1 

meaning 100% of the variability in the dependent variable is described by that 

parameter. The adjusted R2 adjusts R2 based on the number of independent variables 

added to the regression equation. The SE describes the accuracy of the regression 

estimate, as SE increases the reliability of the regression results decreases. 

 
Secchi Depth Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

25

V. Water Quality Status and Trends Results for the 

CHEVWQMN from 1998-2005 

A. Introduction 

 The following section describes the water quality status and trends results of the 

CHEVWQMN from 1998 - 2005. Thirteen parameters were analyzed for each estuary 

and are included in this section with the site specific results given in Appendix A. To 

characterize water quality status as it relates to estuarine health, median values for 

each parameter were compared to typical Florida estuarine water quality values, as 

listed in Hand 2004, and available regulatory criteria. Summary statistics and status 

results are provided in tables included in the sections for each parameter. Seasonal 

and spatial comparisons are included to describe significant differences between 

estuaries and seasons for each parameter. Comparison results are reported in box 

plots for visual reference with detailed results included in Appendix B. Trend analyses 

were conducted for each estuary and the results are shown in graphs and tables in 

each of the following parameter sections. 

 To accurately interpret CHEVWQMN water quality status and trends results, 

consideration should be given to watershed influences and hydrologic effects outside of 

the estuarine system. Specifically, land uses in the adjacent watersheds affect water 

quality conditions and trends in each of the Charlotte Harbor estuary regions to varying 

degrees. The intensity of the land use and proximity to surface water, as well as 

hydrologic conditions determines the magnitude of water quality impacts. For example, 

excess fertilizer application, septic system leachate, stormwater runoff, and phosphate 

mining have the potential to contribute to increased turbidity, nitrogen and phosphorus 

loads to the estuaries, thereby affecting certain response variables such as chlorophyll 

a, water clarity and dissolved oxygen. Altering hydrologic regimes, such as increases in 

channelization and impervious surfaces in the watershed, as well as changes to the 

Caloosahatchee River discharges and Peace River withdrawals, also affect water 

quality and estuarine health. 

 In addition to watershed influences, when interpreting water quality results, it is 

also important to understand weather patterns which occurred during the study period 

and their potential effects on water quality in the Charlotte Harbor estuary regions, such 

as the El Nino-Southern Oscillation (ENSO). In particular, for the study period from 

1998 through 2005, the weather pattern known as the Atlantic Multidecadal Oscillation 

(AMO) affected the southwest Florida area (Enfield et al. 2001). The AMO describes a 

cycle of warmer, drier weather patterns followed by cooler periods with increased 

intensity and variability in rainfall. Historically, warmer phases included the time periods 

from 1860 -1880 and 1940 -1960, while cooler phases included 1905 -1925 and 1970-

1990. Since 1995, studies indicate that a warmer AMO phase is beginning, resulting in 

increased global temperatures and rainfall (Enfield et al. 2001). Increases in rainfall in 

southwest Florida associated with the warmer AMO phase could potentially increase the 

volume of freshwater entering surface tributaries and discharging into the region. 

During the study period, an ENSO event was documented, as well. The result of which 

caused drought conditions for the entire state from 1998-2002 (Verdi et al 2006). The 
Secchi Depth Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

26

combined effect of these two large scale weather patterns was to essentially split the 

study into two periods of differing hydrologic conditions. The first period, 1998-2000, 

represented a period of decreasing precipitation, leading into drought conditions. The 

later period, 2001-2005, was represented by increasing rainfall, and subsequently 

increasing discharge to the estuaries. See Table 5.1 and Figure 5.1 for annual average 

rainfall and Appendix E for correlations of rainfall and study parameters. 

In addition, impacts from Hurricane Charley in August of 2004 have had serious 

immediate and long-term effects on water quality and estuarine health of the Charlotte 

Harbor region. Although the exact nature of these effects is still being examined, 

studies have indicated that specific impacts from Hurricane Charley on water quality in 

the Charlotte Harbor watershed include: immediate, short-term hypoxia in Charlotte 

Harbor and within the Peace River (Tomasko et al. 2006, Stevens et al. 2006), 

increased organic matter (Tomasko et al. 2006) and increased nutrients and fecal 

pollution (Mallin and Corbett 2006). 

 Increases in the amount of freshwater inflow can potentially have various effects 

on water quality parameters, including increases in dissolved organic matter, nutrient, 

pollutant and sediment loads and decreases in pH and salinity. As a result, large scale 

temporal patterns in climate, and subsequently hydrological conditions, can have 

significant impacts upon the status and trends results presented within the report. 

Therefore, the reader should keep in mind the larger scale influences, particularly 

changes climate and precipitation, on water quality results presented here. 

Table 5.1: Average annual rainfall (m) by watershed region. 

 Peace 

Lemon 

Bay Myakka 

Charlotte 

Harbor 

Tidal 

Caloosahatchee 

Estero 

Bay 

1998 1.41 1.45 1.45 1.30 1.68 1.46

1999 1.22 1.30 1.42 1.05 1.32 1.46

2000 0.78 0.84 0.95 0.92 1.00 1.22

2001 1.23 1.20 1.35 1.24 1.46 1.53

2002 1.51 1.37 1.48 1.39 1.40 1.40

2003 1.34 1.55 1.61 1.47 1.70 1.75

2004 1.59 1.33 1.59 1.40 1.59 1.19

2005 1.59 1.55 1.72 1.68 1.86 1.56
Secchi Depth Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

27

? Peace

> Lemon Bay

& Myakka

$ Charlotte Harbor

H Tidal Caloosahatchee

5 Estero Bay

Watershed

1998 2000 2002 2004

Year

0.75

1.00

1.25

1.50

1.75

Average Annual Ra ni fall m( )

?

?

?

?

?

?

? ?

>

>

>

>

>

>

>

>

&

&

&

&

&

& &

&

$

$

$

$

$

$

$

H $

H

H

H

H

H

H

H

5 5

5

5

5

5

5

5

Figure 5.1: Average annual rainfall by watershed region. 
Secchi Depth Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

28

B. Secchi Depth 

1. Background 

 Secchi depth can be used to provide an estimate of water clarity in aquatic 

systems (Kirk 1983). Water clarity, as measured by Secchi depth, is a function of light 

absorption from seawater, dissolved organic and inorganic matter, suspended organic 

matter (i.e. plant biomass and phytoplankton abundance) and suspended inorganic 

matter (i.e. turbidity and total suspended solids; McPherson and Miller 1987). As water 

clarity decreases, Secchi depth decreases. Evaluating the status and trends of water 

clarity as measured by Secchi depth is a useful tool in aquatic resource management. 

Studies in southwest Florida have shown that decreases in water clarity may result in 

decreased seagrass abundance (e.g. EPA 1993). 

 CHEVWQMN Secchi depth values may be affected by shallow sample depths at 

some sites and tide stages, as well as the early morning, low sunlight sampling time. 

As a result, analysis of CHEVWQMN Secchi depth results was limited to sites and dates 

when water depth exceeded Secchi depth. For this report, when Secchi depth was 

greater than water depth, the value was considered missing and not used for analysis. 

In addition, it is also important to remember that Secchi depth is a measure of image or 

visual attenuation and not a direct measure of diffuse light in the water column, nor does 

it take into account specific wavelengths that may be required for seagrass 

photosynthesis (Kirk 1983). As a result, Secchi depth should serve as an estimate of 

light available for photosynthetic growth. Results were not corrected for tidal stage or 

wind speed/direction. 

2. Status and Trends Results 

 Secchi depth summary statistics and status results from the CHEVWQMN for 

1998 - 2005 throughout the Charlotte Harbor region are shown in Tables 5.2 and 5.3 

and Figures 5.2-5.4. For the entire region and the study period, Secchi depth values 

ranged from less than 0.1 m to 4.5 m, with a median value of 0.9 m and a mean value of 

1.3 m. Secchi depth varied significantly between all estuary regions (p <0.05). The 

estuary region with the highest median Secchi depth value was Matlacha Pass at 1.6 m. 

The lowest estuary regional median values were found in Upper Charlotte Harbor and 

Upper Lemon Bay with median values of 0.9 m. Compared to Typical Florida Water 

Quality Values (Hand 2004), higher than average median Secchi depth values, 

indicating above average water clarity conditions, were found in six of the estuary 

regions including: Lower Lemon Bay, Lower Charlotte Harbor, Cape Haze, Pine Island 

Sound, Matlacha Pass and San Carlos Bay. Average Secchi depth values were found 

in three regions: Upper Lemon Bay, Upper Charlotte Harbor and Estero Bay. Because 

there is no water quality criteria for Secchi depth established in Florida, no regulatory 

comparisons were made. For site specific Secchi depth summary statistic and status 

results, see Appendix A. 

 Seasonally, Secchi depth varied significantly (p<0.05), with a region wide median 

value of 1.2 m in the dry season and 1.1 m in the rainy season. Dry season Secchi 

depth values were significantly higher (p<0.05) than rainy season values in five estuary 
Secchi Depth Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

29

regions: Upper Lemon Bay, Upper Charlotte Harbor, Lower Charlotte Harbor, Matlacha 

Pass and San Carlos Bay. There were no significant differences between rainy season 

and dry season Secchi values in four estuary regions: Cape Haze, Estero Bay, Lower 

Lemon Bay and Pine Island Sound. For a visual comparison of seasonal results, see 

Figure 5.3 with detailed statistical results in Appendix B. 

Secchi depth trend analysis was only conducted for estuary regions when at 

least 50% of Secchi depth observations were less than water depth. See Section IV-H 

for an overview of censoring and criteria for trend analysis. Four estuary regions 

qualified for trend analyses: Upper Charlotte Harbor, Matlacha Pass, San Carlos Bay 

and Estero Bay. Of these, only San Carlos and Estero Bays showed a significant 

(p<0.05) change in Secchi depth over the study period, increasing at approximately 0.07 

and 0.05 m per year, respectively. For visual trend assessment time series plots are 

included in Figure 5.4, with detailed analysis results in Table 5.3. 

 

3. Discussion 

 Throughout the study region and period, water clarity, as measured by Secchi 

depth, varied greatly. Values ranged from higher than average to lower than average 

compared to typical Secchi depth values for Florida's estuaries. The highest Secchi 

depth values often occurred at deeper sites, further offshore. Secchi depth values were 

typically lower in regions with strong freshwater flow, including Upper Charlotte Harbor 

and Upper Lemon Bay. Lowest Secchi depth values occurred at sites near the Tidal 

Peace River, Tidal Myakka River and smaller tributaries to Upper Lemon Bay. Also, 

because trend analysis was only conducted for estuaries where a minimum of 50% of 

Secchi depth samples resulted in measurable values, only estuaries with the greatest 

sample depths (Matlacha Pass and San Carlos Bay) or particularly low water clarity 

(Upper Charlotte Harbor) qualified for trend analysis. 

 In the Charlotte Harbor region, changes in Secchi depth can be attributed to 

fluctuations in dissolved organic matter (i.e. color), phytoplankton and non-algal 

suspended matter (Kirk 1983, Dixon and Kirkpatrick 1999, Ott et. al. 2006, McPherson 

and Miller 1994, McPherson and Miller 1987), as well as changes in the light field at the 

time of measurement (Corbett 2006, personal communication). As a result, increases in 

one or more of these constituents may result in decreased water clarity and Secchi 

depth. Color, chlorophyll a, and turbidity levels can be influenced by various changes in 

the estuarine environment and watershed, including: 1) freshwater inputs from major 

rivers, such as the Peace, Myakka and Caloosahatchee Rivers, as well as smaller 

tributaries (Doering and Chamberlain 1999, Doering et. al. 2006, McPherson and Miller 

1990, McPherson et. al 1990); 2) resuspension of sediment or particulates from 

dredging and wave action; and 3) point and non-point source watershed runoff (Doering 

and Chamberlain 1999). 
Secchi Depth Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

30

Figure 5.2: Secchi depth Box plot results for each estuary region. Outliers and 

extremes are not shown. 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.00

1.00

2.00

3.00

4.00

Secchi Depth m( )

Table 5.2: Summary and status of Secchi depth (m) results for each estuary region

N Min Max Mean SE Median

Average

Depth of 

region‡

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 161 0.4 1.6 0.9 0.0 0.9 1.2 1 40 average

Lower Lemon Bay 230 0.5 3.3 1.3 0.0 1.3 1.8 4 70 higher than average

Upper Charlotte 394 0.1 2.7 0.9 0.0 0.9 2.5 1 40 average

Lower Charlotte 105 0.5 4.5 1.8 0.1 1.5 3.0 7 80 higher than average

Gasparilla/Cape Haze 86 0.0 3.2 1.5 0.1 1.5 1.3 7 80 higher than average

Pine Island Sound 167 0.1 3.9 1.4 0.0 1.3 1.7 4 70 higher than average

Matlacha Pass 202 0.4 3.8 1.6 0.0 1.6 1.9 9 80 higher than average

San Carlos Bay 327 0.5 3.9 1.5 0.0 1.4 2.1 6 80 higher than average

Estero Bay 177 0.3 2.9 1.2 0.0 1.1 1.1 3 60 average

All Sites 1849 0.0 4.5 1.3 0.0 0.9 2.0 40 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***below average < 40, 40 < average < 70, above average > 70

‡Average depth calculated from bathymetry maps
Secchi Depth Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

31

Figure 5.3: Seasonal Secchi depth Box plot results for each estuary region. Outliers 

are not shown. Dry Season Rainy Season 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.00

1.00

2.00

3.00

4.00

Secchi Depth m( )
Secchi Depth Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

32

. 

Figure 5.4: Time series plot of Secchi (m) for 1998 through 2005. Each line/point 

represents the monthly median from all sites in each aquatic preserve. 

Upper Charlotte Lower Charlotte Cape Haze

Estero Bay San Carlos Bay Lower Lemon Bay

Upper Lemon Bay Matlacha Pass Pine Island Sound

1.00

2.00

3.00

Secchi (m) 1.00

2.00

3.00

Secchi (m)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

1.00

2.00

3.00

Secchi (m)

05-MAR-1999

27-JAN 2- 001

23-DEC-2002

16-NOV 2- 004

Date

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV 2- 004

Date

Table 5.3: Secchi depth (m) trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept

Upper Lemon Bay * * * * *

Lower Lemon Bay * * * * *

Upper Charlotte 96 53 1.887 0.158 0.0592

Lower Charlotte * * * * *

Gasparilla/Cape Haze * * * * *

Pine Island Sound * * * * *

Matlacha Pass 95 7 0.2190 0.0210 0.8269

San Carlos Bay 94 80 2.9290 0.2480 0.0034 0.0683 1.1430

Estero Bay 85 52 2.14 0.195 0.0324 0.05 1.025

Bold values significant at the .05 level

* does not meet data disposition requirments, See section IV-H 
Temperature Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

33

C. Temperature 

1. Background 

Temperature is an important, controlling factor in a variety of biological and 

chemical processes in estuaries and may serve as a predictor of biological activity. For 

example, temperature plays a key role in seasonal seagrass and phytoplankton 

productivity and triggers life stage changes in many fishery and shellfish species. In 

estuaries in general, and in Charlotte Harbor specifically, temperature varies with depth, 

mixing by tidal currents and wind action, season, time of day and anthropogenic 

influences (EPA 1993). Seasonal temperature stratification occurs in the deeper areas 

of the Harbor, associated with summer salinity stratification due to increased freshwater 

inflows. 

2. Status and Trends Results 

 Temperature summary statistics and status results from the CHEVWQMN for 

1998 - 2005 throughout the Charlotte Harbor region are shown in Tables 5.4 and 5.5 

and Figures 5.5-5.7. Throughout the study region and period, temperature ranged from 

4o

 - 32o C, with a median value of 24o C and a mean value of 23.8o C. Temperature did 

not vary significantly between estuaries, with median values ranging from 24.0o

 - 25.0o

C. Compared to Typical Florida Water Quality Values (Hand 2004), average median 

temperature values were found in all nine of the regions. In addition, since there are no 

temperature water quality criteria in the Charlotte Harbor area, no regulatory 

comparisons were made. For site specific temperature summary statistic and status 

results, see Appendix A. 

 Dry season temperature values were significantly (p<0.05) lower than rainy 

season values in all nine estuary regions and the region as a whole. For the entire 

region, the median dry season temperature was 21.0o

 C and the median rainy season 

value was 28o

 C. For a visual comparison of seasonal results, see Figure 5.6, with 

detailed statistical results in Appendix B. 

 Adequate temperature sample sizes were collected, throughout the study region 

and period to conduct trend analyses for each estuary. Three regions (Matlacha Pass, 

San Carlos Bay, and Estero Bay) showed significant (p<0.05) decreases in 

temperature, and ranged from -0.1 to -0.2 degrees per year. For visual trend 

assessment, time series plots are included in Figure 5.7, with detailed analysis results in 

Table 5.5. 
Temperature Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

34

Figure 5.5: Temperature Box plot results for each estuary region. Outliers and 

extremes are not shown. 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

10.00

20.00

30.00

Tempera ut re D( egrees Celsius)

Table 5.4: Summary and status of temperature (deg. C) results for each estuary region

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 381 12.0 32.0 23.7 0.2 24.5 3 60 average

Lower Lemon Bay 525 10.0 32.0 23.6 0.2 24.0 1 60 average

Upper Charlotte 657 4.0 31.5 23.6 0.2 24.0 1 60 average

Lower Charlotte 252 13.0 31.5 23.9 0.3 24.5 3 60 average

Gasparilla/Cape Haze 192 7.5 31.5 24.2 0.3 25.0 8 60 average

Pine Island Sound 400 10.5 31.0 23.6 0.2 24.5 3 60 average

Matlacha Pass 261 13.5 31.0 24.0 0.3 24.5 3 60 average

San Carlos Bay 340 10.0 31.0 24.1 0.3 24.8 7 60 average

Estero Bay 361 14.0 31.0 23.6 0.2 25.0 8 60 average

All Sites 3369 4.0 32.0 23.8 0.1 24.0 60 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***lower than average < 40, 40 < average < 70,higher than average > 70
Temperature Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

35

Figure 5.6: Seasonal temperature Box plot results for each estuary region. Outliers are 

not shown. Dry Season Rainy Season

 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

10.00

20.00

30.00

Tempera ut re D( egrees Celsius)
Temperature Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

36

Figure 5.7: Time series plot of temperature (°C) for 1998 through 2005. Each line/point 

represents the monthly median from all sites in each aquatic preserve. 

Upper Charlotte Lower Charlotte Cape Haze

Estero Bay San Carlos Bay Lower Lemon Bay

Upper Lemon Bay Matlacha Pass Pine Island Sound

15.00

20.00

25.00

30.00

Temperature D( egrees Celsius) 15.00

20.00

25.00

30.00

Temperature D( egrees Celsius)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

15.00

20.00

25.00

30.00

Temperature D( egrees Celsius)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

Table 5.5: Temperature (deg. C) trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept

Upper Lemon Bay 90 0 0.0000 0.0000 1.0000

Lower Lemon Bay 96 -23 -0.8090 -0.0680 0.4184

Upper Charlotte 96 -48 -1.718 -0.143 0.0858

Lower Charlotte 94 -35 -1.2730 -0.1090 0.2029

Gasparilla/Cape Haze 93 -24 -0.8770 -0.0760 0.3806

Pine Island Sound 95 -22 -0.7770 -0.0670 0.4374

Matlacha Pass 95 -55 -2.0010 -0.1670 0.0454 -0.125 25.06

San Carlos Bay 94 -67 -2.4470 -0.2080 0.0144 -0.1937 25.62

Estero Bay 94 -56 -2.0540 -0.1740 0.0400 -0.2 25.9

Bold values significant at the .05 level
Dissolved Oxygen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

37

D. Dissolved Oxygen

1. Background 

Dissolved oxygen (DO) is critical for sustaining most aquatic life. It is a measure 

of the amount of gaseous oxygen dissolved in the water column and is required for 

metabolism for all aerobic organisms, including estuarine shellfish, crustaceans and 

fishes. In estuaries, DO is produced by photosynthesis of phytoplankton, seagrasses, 

macro algae, as well as other macrophytes, and may serve as an indicator of biotic 

productivity and estuarine health. In the water column, DO also enters from dissolution 

from the atmosphere (Stickney 1984) and through wind and wave action. There is a 

maximum amount of oxygen that can be dissolved in the water (i.e. saturation; 

approximately 8 mg/L in south Florida estuaries), which depends on water temperature 

and salinity, though super saturation can occur due to high rates of photosynthesis and 

surface mixing caused by wind and wave activity. The DO is utilized, and therefore 

reduced by respiration of aquatic organisms and decomposition of organic matter. 

Levels of DO vary on a daily cycle in response to higher mid-day photosynthesis rates, 

followed by night time respiration, resulting in lowest values immediately prior to 

sunrise. The magnitude of the diurnal cycle of DO indicates if the aquatic system is well 

balanced or over-productive due to elevated nutrient and phytoplankton levels (e.g. 

Stickney 1984). 

 Stratification of DO can occur when bottom and surface water layers remain 

separated due to density differences associated with salinity or temperature variations 

(Camp et al. 1998). Once stratification is established, decreased oxygen in the lower 

layer occurs as a result of benthic respiration and decomposition of organic material. In 

Charlotte Harbor, low oxygen (hypoxia) conditions occur in the deeper areas during 

summer stratification (Morrison, et al. 1998, Camp et. al. 1998). 

2. Status and Trends Results 

 The DO concentrations summary statistics and status results from the 

CHEVWQMN for 1998 - 2005 throughout the Charlotte Harbor region are shown in 

Tables 5.6-5.9 and Figures 5.8-5.10. Throughout the study region and period, DO 

values ranged from 0.6 mg/L to 10.0 mg/L, with a median value of 5.2 mg/L and a mean 

value of 5.1 mg/L. The DO values varied significantly (p<0.05), across the nine regions, 

with median values ranging from 5.9 mg/L in Pine Island Sound and San Carlos Bay to 

3.9 mg/L in Upper Lemon Bay. Compared to Typical Florida Water Quality Values 

(Hand 2004), above-average median DO values were not found in any of the regions. 

Average median DO values were found in Pine Island Sound and San Carlos Bay, with 

below average values found in the other seven estuary regions. For site specific DO 

summary statistic and status results, see Appendix A.

 Throughout the region, dry season median DO values (5.7 mg/L) were 

significantly higher (p<0.05) than rainy season median values (4.3 mg/L). In addition, 

estuary median DO values were significantly higher in the dry season in all estuary 

regions. For a visual comparison of seasonal results, see Figure 5.9, with detailed 

statistical results in Appendix B. 

 To characterize the status of DO in the region, CHEVWQMN DO results were 
Dissolved Oxygen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

38

compared to Florida Surface Water Quality Standards for DO. For fresh and marine, 

fishable and swimmable waters (Class III), the DO standards are given in Florida 

Administrative Code Chapter 62-302.530 FAC as: 

 “dissolved oxygen shall not be less than 5.0 mg/L for fresh waters, and shall not 

average less than 5.0 mg/L in a 24 hour period and shall never be less than 4.0 

mg/L in marine waters, with maintenance of normal daily and seasonal 

fluctuations”. 

 In estuarine waters, the use of fresh or marine DO criteria is dependent on 

salinity. Due to the strong tidal and seasonal fluctuation of salinity in the Charlotte 

Harbor estuaries, a generalized comparison to both standards of 4.0 and 5.0 mg/L was 

made. In addition, because of the monthly sampling frequency, daily DO averages 

could not be obtained. However, samples with median values less than 5.0 and 4.0 

mg/L for each site and estuary were analyzed. 

 During the study period, DO levels were frequently observed below the state 

standards of 5.0 mg/L (45% of samples) and 4.0 mg/L (24% of samples). The highest 

DO observations were reported at sites in San Carlos Bay with only 16% of samples 

less than 5.0 mg/L and 2% less than 4.0 mg/L. The most observations below state 

standards occurred in Upper Charlotte Harbor, Estero Bay, Gasparilla/Cape Haze and 

Lower and Upper Lemon Bay (in increasing order). The DO levels in Upper Lemon Bay 

were below 5.0 mg/L for 74% of samples and below 4.0 mg/L for 50% of samples. 

Seasonally, DO concentrations across all sites were lower than both the 5.0 and 4.0 

mg/L standards nearly twice as often during the rainy season. Results comparing DO 

concentrations to regulatory criteria for each estuary are included in Tables 5.7 and 5.8, 

with site specific results in Appendix C. 

 Six significant trends in DO were detected across the nine estuary regions. The 

DO concentrations significantly increased in Upper Charlotte Harbor, Lower Charlotte 

Harbor, Pine Island Sound, Matlacha Pass and San Carlos Bay at a rate of increase 

ranging from less than 0.1 mg/L to approximately 0.2 mg/L per year. However, DO 

values significantly decreased in Gasparilla Sound/Cape Haze at a rate of -0.2 mg/L per 

year. For visual trend assessment, time series plots are included in Figure 5.10, with 

detailed analysis results in Table 5.9. 

3. Discussion 

 When interpreting the CHEVWQMN DO results, it is important to remember that 

all samples were taken at sunrise near the water surface and are based on duplicate 

field measurements at each site. Additionally, many of the sites are located in shallow 

waters near shore. Because of this sampling design, the results represent the lowest 

daily DO values found following night-time absence of photosynthesis combined with 

community respiration. In addition, shallow, near shore DO results may exhibit low 

values as a result of consumption of oxygen via decomposition of organic materials 

from shoreline vegetation. In general, DO concentrations for the Charlotte Harbor 

region were below average compared to typical Florida estuarine water quality values 

and were frequently observed below the state standards of 5.0 and 4.0 mg/L. However, 

the DO standards are generally interpreted as the 24 hour diel average and not a single 

sampling event (Beever 2006, personal communication). Although collective results for 

the entire study duration indicate below average DO conditions, an increasing trend in 
Dissolved Oxygen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

39

DO concentrations were observed for many of the estuaries. 

 In Charlotte Harbor, DO values lower than other typical Florida estuaries may be 

due to the synergistic effects of high water temperature, high water color due to tannins, 

high dissolved organic substances and high amounts of decomposition of detritus in 

shallow near-shore waters and anthropogenic sources of nutrients and other materials, 

as well as sampling design (Morrison et al. 1998, Camp et. al. 1998). Additional diurnal 

monitoring of DO to measure daily fluctuations would enhance the understanding of 

whether Charlotte Harbor's relatively low DO values reflect natural estuarine levels or 

adverse anthropogenic impacts which may be detrimental to overall estuarine health. 

Table 5.6: Summary and status of dissolved oxygen (mg/L) results for each estuary region

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 373 1.0 8.8 4.1 0.1 3.9 1 10 lower than average

Lower Lemon Bay 515 0.6 8.2 4.7 0.1 4.8 3 20 lower than average

Upper Charlotte 650 0.6 9.9 5.2 0.1 5.2 5 30 lower than average

Lower Charlotte 247 2.4 9.1 5.4 0.1 5.5 6 30 lower than average

Gasparilla/Cape Haze 188 1.4 7.3 4.6 0.1 4.6 2 20 lower than average

Pine Island Sound 392 0.6 9.0 5.7 0.1 5.9 8 40 average

Matlacha Pass 252 2.0 9.0 5.5 0.1 5.5 6 30 lower than average

San Carlos Bay 334 2.8 8.7 5.9 0.1 5.9 8 40 average

Estero Bay 356 1.2 10.0 4.7 0.1 4.8 3 20 lower than average

All Sites 3307 0.6 10.0 5.1 0.0 5.2 30 lower than average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***below average < 40, 40 < average < 70, above average > 70
Dissolved Oxygen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

40

Table 5.8: Number and % of dissolved oxygen samples under 4 mg/L per Florida Surface Water Regulations 

Under Total % Under Total % Under Total %

Upper Lemon 188 373 50% 66 218 30% 122 155 79%

Lower Lemon 145 515 28% 55 312 18% 90 203 44%

Upper Charlotte 132 650 20% 13 387 3% 119 263 45%

Lower Charlotte 42 247 17% 10 141 7% 32 106 30%

Gasparilla/Cape Haze 59 188 31% 25 109 23% 34 79 43%

Pine Island 54 392 14% 25 232 11% 29 160 18%

Matlacha Pass 32 252 13% 4 149 3% 28 103 27%

San Carlos 6 334 2% 1 199 1% 5 135 4%

Estero Bay 97 356 27% 22 210 10% 75 146 51%

Total 755 3307 23% 221 1957 11% 534 1350 40%

ALL DRY RAIN

Table 5.7: Number and % of dissolved oxygen samples under 5 mg/L per Florida Surface Water Regulations 

Under Total % Under Total % Under Total %

Upper Lemon 277 373 74% 136 218 62% 141 155 91%

Lower Lemon 274 515 53% 123 312 39% 151 203 74%

Upper Charlotte 290 650 45% 82 387 21% 208 263 79%

Lower Charlotte 88 247 36% 31 141 22% 57 106 54%

Gasparilla/Cape Haze 108 188 57% 55 109 50% 53 79 67%

Pine Island 100 392 26% 37 232 16% 63 160 39%

Matlacha Pass 83 252 33% 22 149 15% 61 103 59%

San Carlos 52 334 16% 10 199 5% 42 135 31%

Estero Bay 202 356 57% 83 210 40% 119 146 82%

Total 1474 3307 45% 579 1957 30% 895 1350 66%

ALL DRY RAIN
Dissolved Oxygen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

41

Figure 5.8: Dissolved oxygen Box plot results for each estuary region. Outliers and 

extremes are not shown. 

Figure 5.9: Seasonal dissolved oxygen Box plot results for each estuary region. 

Outliers are not shown. Dry Season Rainy Season 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

2.00

4.00

6.00

8.00

10.00

D si solved Oxygen m( g/l) Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

2.00

4.00

6.00

8.00

10.00

Dissolved Oxygen m( g/l)
Dissolved Oxygen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

42

Figure 5.10: Time series plot of dissolved oxygen (mg/L) for 1998 through 2005. Each 

line/point represents the monthly median from all sites in each aquatic preserve. 

Upper Charlotte Lower Charlotte Cape Haze

Estero Bay San Carlos Bay Lower Lemon Bay

Upper Lemon Bay Matlacha Pass Pine Island Sound

2.00

4.00

6.00

8.00

Dissolved Oxygen (mg/l) 2.00

4.00

6.00

8.00

Dissolved Oxygen m( g/l)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

2.00

4.00

6.00

8.00

Dissolved Oxygen m( g/l)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

05-MAR-1999

27-JAN 2- 001

23-DEC-2002

16-NOV 2- 004

Date

Table 5.9: Dissolved oxygen (mg/L) trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept

Upper Lemon Bay 90 64 2.463 0.218 0.0138 0.1000 3.350

Lower Lemon Bay 96 -17 -0.577 -0.051 0.5638

Upper Charlotte 96 74 2.631 0.220 0.0085 0.0775 4.676

Lower Charlotte 92 60 2.243 0.195 0.0249 0.1000 4.850

Gasparilla/Cape Haze 93 -46 -1.679 -0.146 0.0931

Pine Island Sound 95 48 1.718 0.146 0.0858

Matlacha Pass 94 120 4.380 0.373 0.0000 0.1750 4.763

San Carlos Bay 94 55 1.995 0.171 0.0461 0.0375 5.831

Estero Bay 94 35 1.258 0.109 0.2086

Bold values significant at the .05 level
pH Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

43

E. pH

1. Background 

 An important component of estuarine water quality that affects many biological 

and chemical processes is pH (Stickney 1984). It is a measure of the acidity or 

alkalinity of an aqueous solution. The scale for pH ranges from 0 (acidic) to neutral 

(7.0) to basic (14.0). The pH of natural surface waters is close to neutral and varies 

primarily with salinity, with fresh waters having lower pH (7.0 - 7.5) than seawater (8.0-

8.6; EPA 1993). Because estuaries have wide ranges of salinities depending on the 

mixing of freshwater from rivers with salt water from oceans, pH varies spatially, daily 

and seasonally in estuaries, generally ranging from 7.5 - 8.8 (Day et al 1989, EPA 

1993). The pH also fluctuates as a result of other natural and artificial events including: 

photosynthesis, bacterial activity and anthropogenic sources (EPA 1993). 

Photosynthesis strongly affects pH by removing carbon dioxide from the water and 

reducing carbonic acid levels within the water, which, in turn, raises the pH (Stickney 

1984). Levels of primary productivity influence diurnal changes in pH and excess 

phytoplankton, and other organisms that photo-respire, may dramatically increase pH 

(Stickney 1984). In addition, pH is influenced by the local geology and inflow from 

tributaries. Weathering of carbonate rocks increase pH (Boggs 2006), while the 

decomposition of organic matter will generally lower it (Stickney 1984). 

 Water is naturally well buffered against changes in acidity or alkalinity, with saltier 

water having greater buffering capacity than freshwater. The pH affects concentrations 

of a variety of biological and chemical substances (Stickney 1984). Most aquatic 

organisms are adapted to narrow pH ranges, with optimal pH ranges for many fish 

being about 6.5-8.5 (NOAA 2005). Molluscs and other organisms with calcarious 

exoskeletons need a pH greater than 7.0 in order to avoid calcium dissolution. Metals 

within the estuary may also be affected, as well - as pH decreases, metals re-dissolve 

from anoxic bottom sediments, but as pH increases, metal oxides precipitate out of the 

water column (Stickney 1984). In addition, ammonia toxicity to aquatic organisms 

increases as pH increases. Abnormal pH values have direct and indirect detrimental 

effects upon the estuarine ecosystem and changes in pH should be investigated (Day et 

al 1989). 

2. Status and Trends Results 

 The pH summary statistics and status results from the CHEVWQMN for 1998 - 

2005 are shown in Tables 5.10 and 5.11 and Figures 5.11-5.13. Throughout the region 

and the study period, pH values ranged from 6.4 to 9.0, with a median value of 7.8 and 

mean of 8.1. Between the nine regions, pH varied significantly (p<0.05). Pine Island 

Sound had the highest median pH value (8.4) and Upper Charlotte Harbor had the 

lowest median pH (7.8). Compared to Typical Florida Water Quality Values (Hand in 

press 2004), average pH values were found in two estuary regions, Upper Lemon Bay 

and Upper Charlotte Harbor. Higher than average pH values were found in the other 

seven estuary regions, with Pine Island Sound ranked in the top 100th percentile of 

Florida’s estuaries. For site-specific pH summary statistics and status results, see 

Appendix A. 
pH Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

44

 The seasonal variation of pH for the region, as a whole, showed interesting 

results. The median dry and rainy season pH values, as well as the mean dry season 

value were each 8.2. However, the mean rainy season pH was 8.1, proving to be 

statistically significantly lower than the dry season. The pH was significantly higher 

(p<0.05) in the dry season for five estuary regions: Upper Lemon Bay, Lower Lemon 

Bay, Upper Charlotte Harbor, Lower Charlotte Harbor, and Matlacha Pass. For a visual 

comparison of seasonal results, see Figure 5.12, with detailed statistical results given in 

Appendix B. 

Florida Surface Water Quality Standards for pH state that: 

“shall not vary more than one unit above or below natural background 

conditions and not below 6.0 units or above 8.5 units for predominantly 

fresh waters, or more than two tenths of a unit above or below natural 

background conditions and not below 6.5 or above 8.5 units in open 

waters” 

 Because natural background pH levels have not been quantified for the Charlotte 

Harbor estuarine region, a detailed status analysis compared to pH regulatory criteria 

was not conducted. However, only two samples were observed below 6.5 and less than 

15% of samples were reported above 8.5. 

 Significant pH trends were found in six of the Charlotte Harbor estuary regions. 

The pH decreased significantly in Upper Lemon Bay, Lower Charlotte Harbor, 

Gasparilla/Cape Haze and Estero Bay, at rates less than 0.05 standard unit per year. 

However, pH increased significantly in Pine Island Sound and Matlacha Pass, at rates 

of less than 0.05 standard unit per year. For visual trend assessment, time series plots 

are included in Figure 5.13, with detailed analysis results in Table 5.11. 

3. Discussion 

 Higher than average pH values were observed across the region. In general, 

estuaries with higher salinity and less freshwater influence had higher pH results. Sites 

with the lowest pH values were found closest to freshwater sources, particularly near 

the Tidal Peace and Tidal Myakka Rivers and the tributary creeks to Upper and Lower 

Lemon Bay. Changes in pH in aquatic systems are strongly associated with variations 

in salinity and photosynthesis (Stickney 1984, Day et. al. 1989). As both salinity and 

photosynthesis increase, pH also increases. As a result, the higher pH results from the 

CHEVWQMN may be linked to above average salinities and/or chlorophyll a levels at 

specific sampling sites or times, or due to the carbonate bedrock found within southwest 

Florida. In addition, due to the strong relationship between pH and salinity, the pH 

trends found over the study region and period could be a result of changes in salinity 

over the time period. 
pH Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

45

Table 5.10: Summary and status of pH results for each estuary region

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 377 7.2 8.8 8.0 0.0 8.0 2 60 average

Lower Lemon Bay 520 7.2 9.0 8.3 0.0 8.3 8 90 higher than average

Upper Charlotte 657 6.4 8.6 7.7 0.0 7.8 1 40 average

Lower Charlotte 249 7.4 8.6 8.3 0.0 8.2 3 90 higher than average

Gasparilla/Cape Haze 194 7.2 8.6 8.3 0.0 8.2 3 90 higher than average

Pine Island Sound 388 7.0 8.8 8.4 0.0 8.4 9 100 higher than average

Matlacha Pass 250 7.4 8.6 8.2 0.0 8.2 3 90 higher than average

San Carlos Bay 339 7.4 8.6 8.3 0.0 8.2 3 90 higher than average

Estero Bay 357 7.2 8.8 8.1 0.0 8.2 3 90 higher than average

All Sites 3331 6.4 9.0 8.1 0.0 7.8 40 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***lower than average < 40, 40 < average < 70, higher than average > 70
pH Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

46

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

6.00

7.00

8.00

9.00

ph

Figure 5.11: pH Box plot results for each estuary region. Outliers and extreme values 

are not shown 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

6.00

7.00

8.00

9.00

ph

Figure 5.12: Seasonal pH Box plot results for each estuary region. Outliers are not 

shown. Dry Season Rainy Season 
pH Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

47

Figure 5.13: Time series plot of pH for 1998 through 2005. Each line/point represents 

the monthly median from all sites in each aquatic preserve. 

Upper Charlotte Lower Charlotte Cape Haze

Estero Bay San Carlos Bay Lower Lemon Bay

Upper Lemon Bay Matlacha Pass Pine Island Sound

7.20

7.60

8.00

8.40

pH 7.20

7.60

8.00

8.40

pH

05-MAR 1- 999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

7.20

7.60

8.00

8.40

pH

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

05 M- AR-1999

27-JAN-2001

23-DEC-2002

16-NOV 2- 004

Date

Table 5.11: pH trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept

Upper Lemon Bay 90 -99 -3.918 -0.337 0.0001 -0.0400 8.180

Lower Lemon Bay 96 -42 -1.553 -0.125 0.1205

Upper Charlotte 96 2 0.037 0.006 0.9704

Lower Charlotte 93 -59 -2.259 -0.187 0.0239 -0.0167 8.325

Gasparilla/Cape Haze 93 -82 -3.198 -0.260 0.0014 -0.0286 8.429

Pine Island Sound 94 62 2.340 0.193 0.0193 0.0113 8.349

Matlacha Pass 95 64 2.380 0.195 0.0173 0.0200 8.110

San Carlos Bay 94 -19 -0.686 -0.059 0.4927

Estero Bay 94 -67 -2.595 -0.208 0.0095 -0.0121 8.255

Bold values significant at the .05 level
Salinity Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

48

F. Salinity

1. Background 

 Salinity is the driving influence in many chemical, physical and biological 

processes in estuaries (Stickney 1984). Large variations in salinity have shown to be 

characteristic of many estuaries (e.g. McPherson et al 1996). Open ocean salinity 

ranges between 33 and 37 parts per thousand (ppt; Colling 2004)), while estuaries 

typically vary from 0.6 to greater than 40 ppt (Stickney 1984). Salinities over 32 ppt 

often occur in areas with minimal freshwater influence and increased evaporation. 

Sources of freshwater in estuaries include runoff from the surrounding watershed, direct 

freshwater inflows from rivers, creeks or canals, and precipitation. During the summer 

rainy season within Charlotte Harbor, vertical salinity stratification occurs due to density 

differences between marine waters and increased freshwater inflows (Stoker 1992). In 

some parts of Charlotte Harbor, a difference of up to 20 parts per thousand may be 

observed between the fresher water remaining at the surface and the saltier water 

trapped below (Stoker 1992). 

 Changes in salinity affect many biological, chemical and physical processes 

within the estuarine system. Many estuarine keystone species are adapted to particular 

salinity ranges including fish (Bortone et. al. 2006), seagrass (Greenawalt et. al. 2006; 

Corbett et. al 2005; Chamberlain and Doering 1998) and shellfish (Baker et al. 2002). 

Salinity may also influence concentrations of DO, pH and nutrients (Stickney 1984). 

Additionally, salinity patterns resulting from freshwater inflows may indicate sources of 

nutrients, dissolved organic matter and solids entering the estuarine system (Stickney 

1984). 

 

2. Status and Trends Results

 Salinity summary statistics and status results from 1998-2005 for the 

CHEVWQMN are given in Tables 5.12 and 5.13 and Figures 5.14-5.16. Throughout the 

study period and region, salinity ranged from less than 0.1 to 42.0 ppt, with a median 

value of 17.9 ppt and mean salinity of 26.1 ppt. Salinity was significantly different 

(p<0.05) between estuaries. Lower Lemon Bay had the highest median salinity (33.5 

ppt), whereas Upper Charlotte Harbor had the lowest salinity (17.9 ppt). Upper Lemon 

Bay (25.3 ppt), Matlacha Pass (22.1 ppt) and Upper Charlotte Harbor (17.9 ppt) had the 

three lowest salinity median values and were average compared to typical Florida 

estuaries (Hand 2004). The remaining six estuaries had higher than average salinities 

compared to other Florida estuaries. Two estuaries regions ranked within the top 100% 

of samples for Florida’s estuaries, Lower Lemon Bay and Gasparilla Sound/Cape Haze 

described in Hand, 2004. Variation in salinity over the entire study duration was 

greatest in Upper and Lower Lemon Bay, Upper Charlotte Harbor and Estero Bay. 

Salinity variability from 1998 through 2005 was lowest in Lower Charlotte Harbor and 

Gasparilla/Cape Haze. For site specific summary statistic and status results, see 

Appendix A. 

 Throughout the region, salinity during the dry season (median 30.1 ppt) was 

significantly higher (p <0.05) than salinity in the rainy season (median 25.9 ppt). 

Comment [REL2]: No unit or 

practical salinity unit (PSU) are now 

more accepted due to systems of 

measurement 
Salinity Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

49

Between the estuaries, salinity was significantly higher in the dry season in all of the 

nine estuaries. For a visual comparison of seasonal results, see Figure 5.15, with 

detailed statistical results given in Appendix B. 

 CHEVWQMN data were not compared to a regulatory standard, because there 

are no water quality criteria specific to salinity in Florida surface waters. 

 From 1998 through 2005, salinity significantly decreased in all estuary regions 

except Lower Lemon Bay. Rates of annual decrease during the study period ranged 

from approximately 0.3 ppt in Gasparilla/Cape Haze to approximately 1.3 ppt in Upper 

Lemon Bay. For visual trend assessment, time series plots are included in Figure 5.16, 

with detailed analysis results given in Table 5.13. 

3. Discussion 

Salinity in the Charlotte Harbor region was generally above the average salinity 

range for Florida’s estuaries. However, a significant decrease in salinity was observed 

over the study duration for eight of the nine estuary regions. Salinity was lowest at sites 

in or near the Tidal Peace and Tidal Myakka Rivers and the smaller tributaries to Lemon 

and Estero Bays. Seasonal fluctuation in salinity concentrations, characterized by 

significantly lower salinity during the rainy season, can be attributed to freshwater inflow 

to Charlotte Harbor (Stoker 1992). Sources of freshwater inflow to Charlotte Harbor 

include the Peace, Myakka and Caloosahatchee Rivers (Stoker 1992, Hammet 1990, 

McPherson et. al. 1996). Freshwater enters the Estero Bay estuary primarily via the 

Caloosahatchee (Byrne and Flanigin 2005), Estero and Imperial Rivers, as well as Ten 

Mile Canal and Hendry Creek, among others (Estero Bay Marine Laboratory 1996). In 

Lemon Bay, freshwater enters the bay through smaller tributaries, including Forked 

Creek, Gottfried Creek, and Oyster Creek. In contrast, higher salinity concentrations 

are a function of tidal flow from the Gulf through passes and inlets throughout Charlotte 

Harbor (Stoker 1992). 

 Salinity in estuaries varies as a result of freshwater inflow to the system which 

can be a function of a variety of natural and artificial factors. Natural factors causing 

increased freshwater flow to the estuaries is primarily the caused by variability and 

intensity of rainfall to region. Rainfall and subsequently flow can be heavily influenced 

by weather patterns and storm events within the region. Weather patterns such as the 

ENSO events or the AMO (Enfield et al. 2001) could account for increased rainfall to the 

Charlotte Harbor region during the study period. Impacts from major storms, particularly 

Hurricane Charley, could have increased rainfall and flow, ultimately impacting salinity 

variability over the study period, particularly in the Fall of 2004. Additional influences on 

salinity variability with the Charlotte Harbor estuaries include alterations in hydrologic 

regimes including changes in runoff due to increased watershed development, 

hydrologic alterations (Stoker 1992) and discharges from the Caloosahatchee River 

(Chamberlain and Doering 1998). Disruptions in natural salinity regimes pose a risk to 

the physical and chemical nature of the estuarine system and biological communities 

that are narrowly adapted to specific salinity ranges (Stoker 1992, Doering and 

Chamberlain 1998, Greenawalt et. al. 2006). 

 
Salinity Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

50

Table 5.12: Summary and status of salinity (ppt) results for each estuary region

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 376 <0.1 40.7 22.4 0.6 25.3 3 60 average

Lower Lemon Bay 518 2.1 40.7 31.7 0.3 33.5 9 100 higher than average 

Upper Charlotte 649 0.0 37.1 17.3 0.4 17.9 1 40 average

Lower Charlotte 248 8.5 39.1 28.2 0.4 29.0 4 80 higher than average 

Gasparilla/Cape Haze 192 10.0 40.7 31.5 0.4 33.2 8 100 higher than average 

Pine Island Sound 399 4.5 42.0 32.2 0.2 32.9 7 90 higher than average 

Matlacha Pass 258 2.9 39.8 21.7 0.5 22.1 2 50 average

San Carlos Bay 339 8.8 41.4 29.1 0.4 30.6 6 90 higher than average 

Estero Bay 357 0.2 39.8 27.5 0.5 30.4 5 80 higher than average 

All Sites 3336 <0.1 42.0 26.1 0.2 17.9 40 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***lower than average < 40, 40 < average < 70, higher than average > 70
Salinity Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

51

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.00

10.00

20.00

30.00

40.00

Salinity (ppt)

Figure 5.14: Salinity Box plot results for each estuary region. Outliers are not shown. 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.00

10.00

20.00

30.00

40.00

Salinity (ppt)

Figure 5.15: Seasonal salinity Box plot results for each estuary region. Outliers are not 

shown. Dry Season Rainy Season 
Salinity Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

52

Figure 5.16: Time series plot of salinity (ppt) for 1998 through 2005. Each line/point 

represents the monthly median from all sites in each aquatic preserve. 

Upper Charlotte Lower Charlotte Cape Haze

Estero Bay San Carlos Bay Lower Lemon Bay

Upper Lemon Bay Matlacha Pass Pine Island Sound

10.00

20.00

30.00

40.00

Salinity (ppt) 10.00

20.00

30.00

40.00

Salinity (ppt)

05 M- AR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

10.00

20.00

30.00

40.00

Salinity (ppt)

05 M- AR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

Table 5.13: Salinity (ppt) trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept

Upper Lemon Bay 90 -91 -3.511 -0.310 0.0004 -1.258 31.06

Lower Lemon Bay 96 -42 -1.468 -0.125 0.1421

Upper Charlotte 96 -65 -2.287 -0.193 0.0222 -0.800 23.55

Lower Charlotte 94 -98 -3.566 -0.304 0.0004 -0.607 31.93

Gasparilla/Cape Haze 93 -87 -3.207 -0.276 0.0013 -0.425 34.81

Pine Island Sound 95 -93 -3.339 -0.283 0.0008 -0.450 34.93

Matlacha Pass 95 -76 -2.721 -0.231 0.0065 -0.950 25.58

San Carlos Bay 94 -65 -2.351 -0.202 0.0187 -0.467 32.85

Estero Bay 94 -107 -3.894 -0.332 0.0001 -0.823 34.40

Bold values significant at the .05 level
Total Nitrogen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

53

G. Nitrogen 

1. Background 

 Nutrients, including nitrogen and phosphorus, are critical components of 

estuarine health. Dissolved nitrogen exists in estuaries in one of two forms; organic and 

inorganic (Stickney 1984). The nitrogen cycle in estuaries is complex due to the quick 

uptake of inorganic nitrogen by photosynthetic organisms and constant remineralization 

within the water column. In estuaries, nitrogen primarily enters the system through 

freshwater inflow, the decomposition of organic matter, or the fixation of atmospheric 

nitrogen by cyanobacteria and some bacteria. When nitrogen is fixed, it is converted 

from gaseous nitrogen (N2) to ammonia. The ammonia is then oxidized through 

nitrification to nitrite by Nitrosomonas spp., then to nitrate by Nitrobacter spp. (Stickney 

1984). Under anoxic conditions, nitrate can be reduced through denitrifiction back to 

nitrite, ammonia, nitrogen gas, or occasionally nitrous oxide (Senga, et al 2006). 

Dissolved Nitrate is readily taken up by aquatic plants and phytoplankton and converted 

to organic nitrogen. These plants and phytoplankton are subsequently ingested by 

primary consumers. Inorganic nitrogen, in the form of ammonia, is then excreted as a 

waste product by some species and converted once again into nitrate by bacteria 

(Stickney 1984). Within the Charlotte Harbor watershed, the most common source of 

anthropogenic nitrogen is from fertilizers (Castro et al 2003). 

 The concentration of dissolved nitrogen in estuaries is determined by other 

physical and chemical influences within the system, as well as the proximity of sources 

and sinks. For example, decreases in DO concentrations may inhibit the nitrification of 

ammonia and nitrite to organic nitrate by bacteria, resulting in increased concentrations 

of nitrite and ammonia (EPA 1993). Nitrogen is also influenced by salinity 

concentrations, with observed decreases in nitrite and nitrate at salinities higher than 20 

ppt (McPherson and Miller 1990). 

 For this study, total nitrogen is the calculated sum of organic nitrogen (plus 

inorganic ammonia) measured as total Kjeldahl nitrogen (TKN), plus inorganic nitrogen 

(minus ammonia) measured as nitrite plus nitrate. 

2. Status and Trends Results 

 The proportion of total nitrogen, in organic or inorganic forms, was assessed to 

help guide the interpretation of total nitrogen results. The percent of organic nitrogen 

plus ammonia, as measured by TKN, was fairly consistent across all estuaries ranging 

from approximately 90% to 95% of the total nitrogen throughout the region (Table 5.13). 

High levels of organic nitrogen may be a possible result of the short residence time of 

inorganic nitrogen within the water column due to quick uptake of by photosynthetic 

organisms (Stickney 1984). 
Total Nitrogen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

54

Total nitrogen summary statistics and status results are given in Tables 5.15 and 

5.16 and Figures 5.17-5.19. Total nitrogen varied significantly (p<0.05) across the study 

area, ranging from 0.032 to 4.6 parts per million (ppm). The total nitrogen median value 

of 0.98 ppm for all sites is higher than average compared to water quality results from 

selected Florida estuaries (Hand 2004). Median nitrogen concentrations were highest 

in Upper Lemon Bay and Upper Charlotte Harbor, ranking in the 80th percentile of 

Florida estuaries as described in Hand, 2004. For site specific summary statistic and 

status results, see Appendix A. 

 Total nitrogen varied seasonally throughout the region. Total nitrogen was 

significantly higher (p<0.05) during the rainy season for each estuary region. The 

difference between the rainy season (0.95 ppm) median and the dry season median 

(0.78 ppm) was approximately 0.18 ppm. For a visual comparison of seasonal results, 

see Figure 5.18, with detailed statistical results given in Appendix B. 

 CHEVWQMN total nitrogen data were not compared to a regulatory standard, 

because there are no numerical criteria for nitrogen in Florida surface waters. 

Trend analysis was not conducted on total nitrogen because over 50% of nitrate 

plus nitrite values (a component of total nitrogen) were reported as equal to or lesser 

than the highest MDL (Table 5.8). As a result, trend analysis for nitrogen for this study 

was conducted on TKN only, however which constitutes almost 95% of nitrogen within 

the system. The TKN significantly decreased in four of the nine estuary regions: Upper 

and Lower Lemon Bay, Lower Charlotte Harbor and Pine Island Sound. Rates of 

decrease during the study period ranged from approximately 0.04 ppm in Lower Lemon 

Bay and Gasparilla/Cape Haze to 0.05 ppm in Upper Lemon Bay and Lower Charlotte 

Harbor. For visual trend assessment, time series plots are shown in Figure 5.19, with 

detailed analysis results given in Table 5.16. 

3. Discussion 

 In general, total nitrogen values from the CHEVWQMN data were average to 

higher than average compared to typical Florida estuarine water quality. Significant 

seasonal variation was observed, as well as a decreasing trend in TKN over the study 

period. The distribution and quantity of nitrogen in the region is largely the result of 

input from tidal flushing, recycling processes, including large biogenic contributions from 

fish-kills, algal decay, vascular plant debris, and freshwater sources (Froelich et.al. 

1985; McPherson and Miller, 1990). Nitrogen primarily enters Charlotte Harbor via 

freshwater inflow from major rivers including the Peace (55%), Caloosahatchee (40%) 

and Myakka River (5%; Hammett 1990), with additional contributions from smaller 

tributaries and runoff. 

 Sources of excess nitrogen in the Charlotte Harbor region may include point and 

nonpoint sources of urban runoff, fertilizer runoff from agricultural applications and 

Table 5.14: Percent of total nitrogen in organic form plus ammonia (TKN)

Upper 

Charlotte 

Harbor

Lower 

Charlotte 

Harbor Cape Haze Estero Bay

San Carlos 

Bay

Lower 

Lemon Bay

Upper 

Lemon Bay

Matlacha 

Pass

Pine Island 

Sound Total

93.19% 94.11% 94.49% 92.10% 90.41% 93.72% 94.81% 93.46% 91.36% 92.92%
Total Nitrogen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

55

atmospheric deposition (Castro et al. 2003). Excess nitrogen could have serious 

impacts on the Charlotte Harbor estuaries, primarily due to increased photosynthetic 

production within the water column (Doering et. al 2006, Montgomery et al. 1991, 

Jaworksi 1981), which may result in decreased water clarity due to increased 

suspended algal matter (Doering et. al 2006), and consequently lower the amount of 

light available for seagrass growth (Corbett 2005) 

 

Table 5.15: Summary and status of total nitrogen (ppm) results for each estuary region

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 219 0.075 2.750 1.035 0.031 1.005 9 80 higher than average

Lower Lemon Bay 265 0.075 2.560 0.790 0.025 0.767 5 60 average

Upper Charlotte 505 0.032 4.602 1.040 0.022 0.975 8 80 higher than average

Lower Charlotte 207 0.055 2.300 0.792 0.028 0.755 3 60 average

Gasparilla/Cape Haze 141 0.075 2.526 0.906 0.042 0.806 6 70 higher than average

Pine Island Sound 309 0.055 4.302 0.808 0.027 0.752 1 60 average

Matlacha Pass 194 0.032 3.840 0.905 0.032 0.851 7 70 higher than average

San Carlos Bay 249 0.055 2.930 0.755 0.025 0.753 2 60 average

Estero Bay 276 0.053 4.046 0.790 0.027 0.762 4 60 average

All Sites 2365 0.032 4.602 0.881 0.010 0.975 80 higher than average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***above average conditions < 40, 40 < average < 70, below average conditions > 70
Total Nitrogen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

56

Figure 5.17: Total nitrogen Box plot results for each estuary region. Outliers are not 

shown. 

Figure 5.18: Seasonal total nitrogen Box plot results for each estuary region. Outliers 

are not shown. Dry Season Rainy Seas

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.000

0.500

1.000

1.500

2.000

Total Nitrogen (ppm)

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.000

0.500

1.000

1.500

2.000

Total Nitrogen (ppm)
Total Nitrogen Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

57

Figure 5.19: Time series plot of total Kjeldahl nitrogen (ppm) for 1998 through 2005. 

Each line/point represents the monthly median from all sites in each aquatic preserve. 

Upper Charlotte Lower Charlotte Cape Haze

Estero Bay San Carlos Lower Lemon

Upper Lemon Matlacha Pass Pine Island Sound

0.00

1.00

2.00

Total Kje dl ahl Nitrogen (ppm) 0.00

1.00

2.00

Total Kjeldahl Nitrogen (ppm)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV 2- 004

Date

0.00

1.00

2.00

Total Kje dl ahl Nitrogen (ppm)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

05-MAR-1999

27-JAN 2- 001

23-DEC-2002

16-NOV-2004

Date

Table 5.16: Total Kjeldahl nitrogen (ppm) trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept

Upper Lemon Bay 80 -47 -2.095 -0.203 0.0362 -0.0535 1.2410

Lower Lemon Bay 81 -47 -2.065 -0.197 0.0389 -0.0380 0.9210

Upper Charlotte 83 -35 -1.484 -0.141 0.1378

Lower Charlotte 83 -69 -2.989 -0.277 0.0028 -0.0500 1.0050

Gasparilla/Cape Haze 81 -39 -1.711 -0.165 0.0870

Pine Island Sound 80 -44 -1.978 -0.190 0.0479 -0.0400 1.0250

Matlacha Pass 81 -42 -1.860 -0.178 0.0629

San Carlos Bay 81 -33 -1.461 -0.140 0.1440

Estero Bay 80 -32 -1.400 -0.136 0.1614

Bold values significant at the .05 level
Phosphorus Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

58

J. Phosphorus

1. Background 

 Phosphorus, like nitrogen, is an essential nutrient for aquatic life yet, in excess, 

poses a threat to water quality and estuary health. All organisms require phosphorus 

for growth and energy transport, and phosphorus is considered to be the ultimate 

limiting nutrient over long (geological) time scales, due to its long residence time in the 

world’s oceans (Benitez-Nelson 2000). However, due to soil and bedrock chemistry 

within the Charlotte Harbor Watershed, Charlotte Harbor and the surrounding region are 

phosphorus enriched (Froelich et al 1985). The phosphorus cycle in aquatic 

environments is somewhat more complex than that of nitrogen due to the constant 

remineralization. Phosphorus enters the aquatic system mostly in the inorganic form 

(P2O4 and PO4

3-) from riverine sources due to the weathering of crustal materials and 

from anthropogenic sources such as deforestation and fertilizer use. To a much lesser 

extent, inorganic phosphorus also enters the aquatic environment via atmospheric 

deposition. This inorganic phosphorus is then available for plant uptake and 

subsequently converted to its organic form within the plant tissue which may then be 

consumed by primary consumers. Finally, organic waste products are once again 

converted to inorganic phosphorus by bacterial remineralization within the microbial 

food web and deposited in the sediment or re-suspended into the water column. This 

process can be extremely rapid and the phosphorus may be recycled from inorganic to 

organic numerous times prior to being burial or flushed from the estuarine system 

(Benitez-Nelson 2000). For this study, phosphorus is the total concentration of organic 

and inorganic forms of phosphorus. 

 Like nitrogen, phosphorus levels in estuaries are a function of physical processes 

that occur naturally within the aquatic environment. For example, when under low DO 

conditions, phosphorus that is bound to sediment particles is released back into the 

water column, resulting in excess of dissolved phosphorus (EPA 1993). In most aquatic 

systems, photosynthetic production is limited by the concentration of phosphorus in the 

water column. However, in the coastal Charlotte Harbor region, the availability of 

nitrogen, rather than phosphorus, limits photosynthetic production, although the 

relationship varies seasonally and spatially (Montgomery et al 1991). Although 

phosphorus is not the primary nutrient limiting photosynthetic growth, excess 

phosphorus in the system could pose serious risks in the Charlotte Harbor region 

(Martin and Kim 1977). 

2. Status and Trends Results 

 Phosphorus summary statistics and status results are given in Tables 5.17 and 

5.18 and Figures 5.20-5.22. Total phosphorus (TP) varied significantly (p<0.05) across 

the study area ranging from 0.005 to 1.5 ppm. The median TP value (0.24 ppm) from 

all sites was higher than average, ranking in the top 90th percentile of Florida’s estuaries 

(Hand 2004). Upper Lemon Bay (0.18 ppm) and Upper Charlotte Harbor (0.24 ppm) 

had the highest TP median values compared to other Charlotte Harbor estuaries and 

were higher than average compared to typical Florida estuaries (Hand 2004). The TP 

values across the remaining estuary regions were average relative to values from 
Phosphorus Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

59

estuaries across the state of Florida (Hand 2004). For site specific summary statistic 

and status results, see Appendix A. 

 Region wide phosphorus varied seasonally across during the study period 

(p<0.05). The TP was significantly higher (p<0.05) during the rainy season in Upper 

Lemon Bay, Upper and Lower Charlotte Harbor and Matlacha Pass. Alternatively, TP 

was significantly higher during the dry season in Estero Bay. There were no significant 

seasonal differences in TP in Gasparilla/Cape Haze, San Carlos Bay, Lower Lemon 

Bay and Pine Island Sound. For a visual comparison of seasonal results, see Figure 

5.21, with detailed statistical results given in Appendix B. 

 There are no numerical criteria for phosphorus for Florida’s estuaries, therefore 

CHEVWQMN TP results were not compared to any defined water quality standards. 

 Only one significant trend in total phosphorus was detected across the nine 

estuary regions. The TP values significantly increased in Upper Charlotte Harbor at a 

rate of 0.01 ppm per year from 1998 through 2005. For visual trend assessment, time 

series plots are included in Figure 5.22, with detailed analysis results given in Table 

5.18. 

3. Discussion 

 The TP in the Charlotte Harbor region was generally average compared to typical 

Florida values, with higher than average phosphorus in Upper Lemon Bay and Upper 

Charlotte Harbor. The TP levels significantly increased in Upper Charlotte Harbor from 

1998 through 2005. Sources of phosphorus in estuaries include fertilizers, agricultural 

and urban land uses, phosphate mining, waste water treatment and storm water runoff, 

as well as natural deposits within the Charlotte Harbor Watershed (EPA 1993, 

Fourqurean and Cai 2001). In the Charlotte Harbor region, freshwater flow from major 

rivers is a source for phosphorus entering the estuary (Morrison et al 1998). The Peace 

River watershed contributes about 85% of total phosphorus loads into the Charlotte 

Harbor estuaries (Hammett 1990). 

Table 5.17: Summary and status of total phosphorus (ppm) results for each estuary region

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 228 0.010 1.080 0.199 0.007 0.180 8 80 higher than average

Lower Lemon Bay 275 0.010 0.420 0.084 0.003 0.070 4 50 average

Upper Charlotte 532 0.010 1.500 0.305 0.009 0.240 9 90 higher than average

Lower Charlotte 215 0.005 0.420 0.114 0.005 0.100 7 60 average

Gasparilla/Cape Haze 150 0.005 0.350 0.093 0.005 0.080 6 50 average

Pine Island Sound 330 0.005 0.900 0.073 0.004 0.060 1 40 average

Matlacha Pass 212 0.010 0.290 0.084 0.003 0.076 5 50 average

San Carlos Bay 263 0.005 0.270 0.069 0.002 0.060 1 40 average

Estero Bay 297 0.005 0.500 0.070 0.003 0.060 1 40 average

All Sites 2502 0.005 1.500 0.140 0.003 0.240 90 higher than average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***above average conditions < 40, 40 < average < 70, below average conditions > 70
Phosphorus Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

60

 Figure 5.20: Total phosphorus box plot results for each estuary region. Outliers are 

not shown. 

 Figure 5.21: Seasonal total phosphorus box plot results for each estuary region. 

Outliers are not shown. Dry Season Rainy Season 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.000

0.200

0.400

0.600

0.800

Total Phospho ur s (ppm)

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.000

0.200

0.400

0.600

0.800

Total Phosphorus (ppm)
Phosphorus Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

61

Figure 5.22: Time series plot of total phosphorus (ppm) for 1998 through 2005. Each 

line/point represents the monthly median from all sites in each aquatic preserve. 

Upper Charlotte Lower Charlotte Cape Haze

Estero Bay San Carlos Bay Lower Lemon Bay

Upper Lemon Bay Matlacha Pass Pine Island Sound

0.000

0.200

0.400

0.600

Total Phosphorus (ppm) 0.000

0.200

0.400

0.600

Total Phosphorus (ppm)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

0.000

0.200

0.400

0.600

Total Phosphorus (ppm)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

Table 5.18: Total phosphorus (ppm) trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept

Upper Lemon Bay 81 19 0.824 0.081 0.4098

Lower Lemon Bay 81 -33 -1.497 -0.140 0.1344

Upper Charlotte 83 50 2.141 0.201 0.0323 0.01 0.225

Lower Charlotte 82 34 1.487 0.140 0.1371

Gasparilla/Cape Haze 80 -9 -0.369 -0.390 0.7120

Pine Island Sound 81 -19 -0.873 -0.080 0.3826

Matlacha Pass 82 15 0.634 0.061 0.5261

San Carlos Bay 82 -16 -0.693 -0.066 0.4884

Estero Bay 83 -27 -1.219 -0.114 0.2229

Bold values significant at the .05 level
Chlorophyll a Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

62

K. Chlorophyll a

1. Background 

 Chlorophyll is a group of green pigments found in plants and is responsible for 

photosynthetic production. Chlorophyll a concentrations within the water column are 

used to estimate the amount of phytoplankton within a water body, which is an indirect 

measure of primary production occurring within the system. The amount of chlorophyll 

a in estuaries varies seasonally and spatially in response to temperature, nutrient levels 

and light availability. Increased levels of chlorophyll a generally bloom as a result of 

increased photosynthesis in the water column stimulated by excess nutrients, primarily 

nitrogen in the Charlotte Harbor estuaries (Montgomery et al. 1991). Because 

photosynthetic production is limited by the availability of nutrients in the system, 

chlorophyll a concentrations are commonly used to estimate the degree of 

eutrophication, or nutrient enrichment, within the estuary (e.g., Doering et. al. 2006). 

 For this study, chlorophyll a concentrations were estimated without correction for 

pheophytin. Pheophytin is a byproduct of chlorophyll a degradation that can be 

observed during analysis at the same absorption spectrum as chlorophyll a but is not 

used in photosynthesis. Subsequently chlorophyll a that is uncorrected for pheophytin 

may overestimate total chlorophyll a concentrations when the amount of pheophytin is 

substantial. It is also important to remember that, due to funding constraints, chlorophyll 

a levels were not analyzed from January 2002 through December of 2002. 

2. Status and Trends Results 

 Chlorophyll a concentration summary statistics and status results from the 

CHEVWQMN are given in Tables 5.19-5.22 and Figures 5.23-5.25. Chlorophyll a levels 

were significantly different (p<0.05) across the study region and period, ranging from 

0.01 to 114.00 μg/L. Chlorophyll a results were generally average to lower than 

average compared to typical Florida estuarine values (Hand 2004) with the median 

value (4.74 μg/L) for all sites ranking in the 40th percentile of Florida estuaries. Upper 

Lemon Bay and Upper Charlotte Harbor had the highest chlorophyll a values of all nine 

estuary regions, with median values greater than 6.00 μg/L. Chlorophyll a 

concentrations were lowest in Gasparilla Sound/Cape Haze, Matlacha Pass and San 

Carlos Bay, with median values lower than average compared to typical Florida 

estuaries (Hand 2004). For site specific summary statistics and status results, see 

Appendix A. 

 Chlorophyll a varied seasonally across the study region. During the rainy season 

the chlorophyll a median value of 6.02 μg/L was significantly higher (p<0.05) than the 

dry season median value of 3.97 μg/L for all estuary regions combined. Surprisingly, 

chlorophyll a concentrations did not vary seasonally in Upper Charlotte Harbor. For a 

visual comparison of seasonal results, see Figure 5.24, with detailed statistical results 

given in Appendix B. 

Chlorophyll a results were compared to state regulatory criteria to characterize 

the status of CHEVWQMN results. The Impaired Waters Rule, 62-303.353 FAC states 

that waters shall are impaired if annual mean chlorophyll a levels exceed 11 μg/L, or 

data indicate an increase of 50% or more from historical values for at least two 
Chlorophyll a Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

63

consecutive years. Annual mean exceedances, as well as frequency and percent 

exceedances over 11 μg/L were analyzed for each site and estuary region. 

 Chlorophyll a annual means exceeded 11 μg/L at sites in Upper Lemon Bay, 

Lower Lemon Bay, Upper Charlotte Harbor, Pine Island Sound and Estero Bay. Annual 

means exceeded 11 μg/L most frequently in 1998, with no exceedances in 2001 or 

2003. For all sites, 15% of samples exceeded 11 μg/L with exceedances occurring 

more frequently in the rainy season (19%) than the dry season (13%). Sites in Upper 

Lemon Bay and Upper Charlotte Harbor most frequently exceeded chlorophyll a

standards with 28% and 25% of samples exceeding 11 μg/L, respectively. 

Exceedances occurred least frequently (less than 10%) at sites in Gasparilla/Cape 

Haze, Matlacha Pass, Estero Bay, San Carlos and Lower Lemon Bay. For annual 

means exceeding 11 μg/L, see Table 5.20 for detailed estuary and site specific 

exceedances, see Appendix C. 

 Changes in chlorophyll a from 1998 through 2005 for each estuary region were 

estimated using the seasonal Kendall trend test and the Mann-Whitney U test. There 

were no significant trends in chlorophyll a throughout the study region. However, it 

should be noted that chlorophyll a results were not available for January 2002 to 

December 2002 because of financial constraints, which may decrease the ability to 

detect significant trends. Therefore, an additional analysis was conducted using the 

Mann-Whitney U test. The Mann-Whitney U test was used to compare differences 

between the collective results from 1998 to December 2001, with the collective results 

from January 2003 through December 2005. For all sites across the study area, 

chlorophyll a results from 1998 through 2001 were significantly lower (p<0.05) than the 

collective results from 2003-2005. However, a post hoc analysis by estuary region 

revealed only two significant differences between the time period groups in Upper and 

Lower Charlotte Harbor. For visual trend assessment, time series plots are included in 

figure 5.25, with detailed analysis results given in Table 5.21. For Mann-Whitney 

results, see Table 5.22. 

3. Discussion 

Chlorophyll a concentrations were generally below average compared to typical 

Florida estuaries (Hand, 2004), although concentrations were frequently observed 

above state regulatory criteria of 11 μg/L. Upper Charlotte Harbor and Upper Lemon 

Bay had the highest median chlorophyll a concentrations and exceeded 11 μg/L most 

often. No significant trends were detected during the time period. However, for all sites 

collectively, chlorophyll a results during the first portion of the study duration (1998-

2001) were significantly lower than the second part of the study period (2003-2005). 

Although these findings alone cannot indicate a significant trend, results indicate that a 

possible increase in chlorophyll a may have occurred from 1998 through 2005. 

 In the Charlotte Harbor region, past studies indicate that increased chlorophyll a 

concentrations are primarily due to increased inorganic nitrogen and vary in response to 

available light within the water column (Montgomery et al. 1991, McPherson et al 1996, 

Doering et. al. 2006). Chlorophyll a concentrations in southwest Florida vary spatially 

and seasonally with nutrient concentrations, tidal circulation, freshwater discharges and 

light attenuating constituents (Doering et al. 2006, Montgomery et al. 1991) affecting 
Chlorophyll a Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

64

other estuarine responses. Effects of increased chlorophyll a levels in the Charlotte 

Harbor estuaries include: 1) increased light attenuation due to increased phytoplankton 

within the water column (Doering et al 2006, Ott et. al. 2006) and 2) hypoxia due to 

increased utilization of DO for decomposition of photosynthetic material (Doering et al 

2006). 

Table 5.20: Chlorophyll a annual means greater than 11 μg/L per Florida's Impaired Waters Rule

N Mean N Mean N Mean N Mean N Mean N Mean N Mean

LBFOR1 6 15.09

LBV001 4 13.81

LBV002 4 22.45 12 11.01

LBV003 5 23.75 11 14.48 9 11.61

LBV004 5 12.54

LBV005 4 23.67

CHV001 5 25.60 8 12.33 10 13.95 12 17.24

CHV002 5 13.39 11 11.54

CHV004 5 13.40 10 11.44

CHV005 5 19.04 11 20.71 11 19.27

CHV006 5 26.23

CHV007 5 11.05

CHV013 11 16.92 12 17.03

PIJIM1 8 11.91

PIV002 5 12.34

PIV004 1 39.70

Estero Bay EBERS2 12 13.13

GSV005 10 13.08

*chlorophyll a was not collected from January 2002 through December of 2002

2005

Lower 

Lemon Bay

Upper 

Charlotte

Pine Island 

Sound

2003 2004

Upper 

Lemon Bay

1998 1999 2000 2001*

Table 5.19: Summary and status of chlorophyll a (μg/L) results for each estuary region

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 209 0.50 52.30 9.22 0.60 6.30 9 60 average

Lower Lemon Bay 255 0.01 79.46 5.55 0.42 3.92 4 40 average

Upper Charlotte 482 0.01 88.50 9.48 0.50 6.16 8 60 average

Lower Charlotte 198 0.01 34.18 5.61 0.35 4.42 6 40 average

Gasparilla/Cape Haze 145 0.50 18.20 4.49 0.31 3.58 3 30 lower than average

Pine Island Sound 298 0.01 39.70 6.52 0.34 4.98 7 40 average

Matlacha Pass 187 0.25 72.50 5.42 0.52 3.50 2 30 lower than average

San Carlos Bay 245 0.01 28.35 4.41 0.25 3.43 1 30 lower than average

Estero Bay 263 0.01 114.00 5.75 0.50 4.39 5 40 average

All Sites 2282 0.01 114.00 6.67 0.17 4.74 40 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***above average conditions < 40, 40 < average < 70, below average conditions > 70
Chlorophyll a Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

65

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.000

10.000

20.000

30.000

Ch ol rophylla(ug/l)

Figure 5.23: Chlorophyll a Box plot results for each estuary region. Outliers are not 

shown. 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.000

10.000

20.000

30.000

Ch ol or phylla(ug/l)

Figure 5.24: Seasonal chlorophyll a Box plot results for each estuary region. Outliers 

are not shown. Dry Season Rainy Season 
Chlorophyll a Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

66

Figure 5.25: Time series plots of chlorophyll a (μg/L) for 1998 through 2005. Each 

line/point represents the monthly median from all sites in each aquatic preserve. 

Table 5.21: Chlorophyll a (μg/L) trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept

Upper Lemon Bay 79 -28 -1.257 -0.125 0.2087

Lower Lemon Bay 79 -30 -1.350 -0.134 0.1770

Upper Charlotte 79 16 0.698 0.071 0.4849

Lower Charlotte 79 -7 -0.280 -0.031 0.7797

Gasparilla/Cape Haze 79 -17 -0.751 -0.076 0.4525

Pine Island Sound 79 -3 -0.093 -0.013 0.9257

Matlacha Pass 79 -7 -0.283 -0.032 0.7772

San Carlos Bay 79 -11 -0.472 -0.050 0.6372

Estero Bay 79 -21 -0.943 -0.096 0.3456

Bold values significant at the .05 level
Chlorophyll a Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

67

Table 5.22: Mann Whitney between subjects results of chlorophyll a from 1998-2001 compared to chlorophyll a from 2003-2005

 N Mean Rank Sum of Ranks Mann-Whitney U Wilcoxon W Z p

1998-2001 1128 1098.58 1239198 602442 1239198 -4.01 0.0000

2003-2005 1182 1209.82 1430007

1998-2001 103 105.31 10847 5427 11098 -0.73 0.9420

2003-2005 106 104.7 11098

1998-2001 111 131.67 14615.5 7584.5 18024.5 -0.70 0.4850

2003-2005 144 125.17 18024.5

1998-2001 242 220.85 53445 24042 53445 -3.27 0.0010

2003-2005 240 262.33 62958

1998-2001 103 89.29 9196.5 3840.5 9196.5 -2.61 0.0090

2003-2005 95 110.57 10504.5

1998-2001 107 98.94 10586.5 4808.5 10586.5 -0.54 0.5920

2003-2005 94 103.35 9714.5

1998-2001 140 145.18 20325.5 10455.5 20325.5 -0.81 0.4150

2003-2005 158 153.33 24225.5

1998-2001 99 87.44 8657 3707 8657 -1.76 0.0790

2003-2005 88 101.38 8921

1998-2001 133 116.87 15544 6633 15544 -1.48 0.1400

2003-2005 112 130.28 14591

1998-2001 114 131.04 14939 8384 14939 -0.18 0.8580

2003-2005 149 132.73 19777

Bold values significant at the .05 level

All Sites

Upper 

Lemon Bay

Lower 

Lemon Bay

Upper 

Charlotte

San Carlos 

Bay

Estero Bay

Lower 

Charlotte

Gasparilla/C

ape Haze

Pine Island 

Sound

Matlacha 

Pass
Fecal Coliform Bacteria Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

68

L. Fecal Coliform Bacteria

1. Background 

 Fecal coliform bacteria are microorganisms that live in the digestive track of 

humans and other warm blooded animals. The presence of fecal coliform bacteria in 

the water column is an important predictor of fecal pollution and may indicate the 

presence of pathogens and viruses that pose serious human health risks. The 

concentration of fecal coliform in coastal waters is controlled by a variety of physical, 

chemical and biological factors. The persistence of coliform bacteria in the estuarine 

environment decreases as salinity and temperature increase (Rhode and Kator 1988). 

Additionally, increased sunlight light penetrating the water column reduces fecal 

coliform bacteria viability and decreased light mitigates this affect (Fujioka et al 1981). 

Also, competition from other microbiological communities may limit the presence and 

productivity of fecal coliforms in estuarine waters (Rhode and Kator 1988). As a result, 

survival and presence of fecal coliforms may be greater in areas exhibiting lower light 

availability, salinity and temperature conditions. 

2. Status and Trends Results 

 Fecal coliform bacteria summary statistics and status results from 1998 - 2005 

are given in Tables 5.23-5.25 and Figures 5.26-5.28. Fecal coliform counts varied 

significantly (p<0.05) across the study region and period, ranging from 1 to 1,156 

cfu/100mL. Fecal coliform bacteria counts were below minimum detection limits (1 to 2 

cfu/100mL) for almost 30% of samples during the study duration. The median coliform 

value, 24 cfu/100mL, of all sites was higher than average compared to Typical Florida 

estuaries (Hand 2004). Upper Lemon Bay and Upper Charlotte Harbor had the highest 

median coliform values of 35 and 24 cfu/100mL, respectively, ranking in the 90th and 

80th percentiles, respectively. Pine Island Sound, San Carlos Bay and Lower Charlotte 

Harbor had the lowest fecal coliform medians of 3 cfu/100mL or less. 

 Across the study region, fecal coliform counts were not significantly different 

between rainy season and dry season. For a visual comparison of results, see Figure 

5.27 with detailed seasonal comparisons in Appendix B. 

 Additional analysis comparing results to state regulatory criteria was conducted 

to characterize the status of fecal coliform bacteria for each estuary region and site. 

Florida’s Surface Water Quality Standards state that fecal coliform bacteria counts per 

100 mL: 

“shall not exceed a monthly average of 200 nor exceed 400 in 10% of the 

samples nor exceed 800 on any one day for Class III marine and fresh waters.”

Because monthly averages could not be obtained at the site level, a general summary 

of exceedances over 200 cfu/100mL was provided. A summary of fecal coliform 

bacteria status results for each site and estuary region, as it relates to Florida Surface 

Water Quality Standards, is provided in Table 5.24. 

 Frequent exceedances of all bacteria standards of 200, 400 and 800 cfu/100mL 

were observed over the duration of the study. A total of 3% of samples across all sites 

exceeded 200 cfu/100mL with 19% exceeding 400 cfu/100mL and less than 1% of 

samples exceeding the 800 cfu/100mL standard. Sites in Upper Lemon Bay had the 
Fecal Coliform Bacteria Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

69

highest percent of samples exceeding 200, 400 and 800 cfu/100mL. Sites GSV005 (not 

within a defined estuary region) and LBV001 in Upper Lemon Bay had the highest 

percent exceedances over 200 cfu/100mL of all sites. There was only one sample 

exceeding 200 cfu/100mL in Lower Charlotte Harbor and no exceedances in Matlacha 

Pass. 

 Fecal coliform counts significantly changed from 1998 through 2005 in one 

estuary region. Coliform counts significantly decreased in Pine Island Sound at less 

that 1 cfu/100mL per year. For visual trend assessment, time series plots are included 

in Figure 5.28, with detailed analysis results given in Table 5.25. 

3. Discussion 

Fecal coliform bacteria were generally below detection limits for most sites 

across the Charlotte Harbor estuaries for the study period. Individual fecal coliform 

bacteria counts exceeded average state standards in Upper and Lower Lemon Bay, 

Upper Charlotte Harbor and Estero Bay. No significant difference was observed 

between seasonal medians or seasonal exceedances of numerical criteria. Although 

one trend in fecal coliform was observed from 1998 through 2005, the rate of change 

was less than 1 cfu/100mL. 

 In the Upper Lemon Bay estuary, faulty septic systems and urban storm water 

outfalls located close to sampling sites, may be the source of above average fecal 

coliform concentrations and require future investigations. The relationship between 

sources of fecal pollution and the presence of fecal coliform bacteria within the 

estuarine environment are not well understood in the Charlotte Harbor region. A 

thorough examination of these relationships is essential in assessing the effects of fecal 

pollution as it relates to estuarine and human health. 

Table 5.23: Summary and status of fecal coliform bacteria (cfu/100mL) results for each estuary region

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 252 1 1156 98 10 35 9 90 higher than average

Lower Lemon Bay 302 1 800 41 5 8 6 60 average

Upper Charlotte 587 1 800 48 4 24 8 80 higher than average

Lower Charlotte 234 1 372 13 2 3 3 50 average

Gasparilla/Cape Haze 169 1 280 20 3 6 5 60 average

Pine Island Sound 383 1 352 13 2 2 1 40 average

Matlacha Pass 234 1 106 9 1 4 4 50 average

San Carlos Bay 310 1 364 12 2 2 1 40 average

Estero Bay 331 1 800 44 5 10 7 70 higher than average

All Sites 2802 1 1156 35 2 24 70 higher than average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***above average conditions < 40, 40 < average < 70, below average conditions > 70
Fecal Coliform Bacteria Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

70

Table 5.24: Fecal coliform exceedances per Florida Surface Water Regulations for each estuary

# over N % # over N % # over N %

Rain 14 104 13% 4 104 4% 1 104 1%

Dry 22 148 15% 9 148 6% 2 148 1%

Total 36 252 14% 13 252 5% 3 252 1%

Rain 6 120 5% 4 120 3%

Dry 5 182 3%

Total 11 302 4% 4 302 1%

Rain 8 239 3% 4 239 2%

Dry 12 348 3% 2 348 1%

Total 20 587 3% 6 587 1%

Rain 1 98 1%

Dry

Total 1 234 0%

Rain 1 67 1%

Dry 1 102 1%

Total 2 169 1%

Rain 2 158 1%

Dry 2 225 1%

Total 4 383 1%

Rain 1 125 1%

Dry 1 185 1%

Total 2 310 1%

Rain 3 137 2%

Dry 10 194 5% 4 194 2%

Total 13 331 4% 4 331 1%

Rain 36 1143 3% 12 1143 1% 1 1143 < 1%

Dry 53 1659 3% 15 1659 1% 2 1659 < 1%

Total 89 2802 3% 27 2802 1% 3 2802 < 1%

Lower Lemon 

Bay

Upper Charlotte

Lower Charlotte

Total

Gasparilla/Cape 

Haze

Pine Island 

Sound

San Carlos Bay

Estero Bay

Coliform > 200 cfu/100mL Coliform > 400 cfu/100mL Coliform > 800 cfu/100mL

Upper Lemon 

Bay
Fecal Coliform Bacteria Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

71

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.00

100.00

200.00

300.00

Fecal Coli of mr Bacter ai (cfu/100ml)

Figure 5.26: Fecal coliform bacteria Box plot results for each estuary region. Outliers 

are not shown.

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.00

100.00

200.00

300.00

Fecal Colifo mr Bacter ai (c uf /100ml)

Figure 5.27: Seasonal fecal coliform bacteria Box plot results for each estuary region. 

Outliers are not shown. Dry Season Rainy Season 
Fecal Coliform Bacteria Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

72

Figure 5.28: Time series plot of fecal coliform (cfu/100mL) for 1998 through 2005. 

Each line/point represents the monthly median from all sites in each aquatic preserve. 

Upper Charlotte Lower Charlotte Cape Haze

Estero Bay San Carlos Bay Lower Lemon Bay

Upper Lemon Bay Matlacha Pass Pine Island Sound

0.00

200. 00

400. 00

600. 00

Fecal Coliform (cfu/100ml)

0.00

200. 00

400. 00

600. 00

Fecal Colifo mr (cfu/100ml)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

0.00

200. 00

400. 00

600. 00

Fecal Colifo mr (cfu/100ml)

05 M- AR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

Table 5.25: Fecal coliform bacteria (cfu/100mL) trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept

Upper Lemon Bay 87 -25 -0.9840 -0.0910 0.3252

Lower Lemon Bay 86 21 0.8330 0.0780 0.4051

Upper Charlotte 87 -21 -0.827 -0.077 0.408

Lower Charlotte 87 -39 -1.5950 -0.1420 0.1107

Gasparilla/Cape Haze 87 42 1.7230 0.1530 0.0848

Pine Island Sound 87 -100 -4.3670 -0.3650 0.0000 -0.2500 3.1250

Matlacha Pass 87 -39 -1.6000 -0.1420 0.1097

San Carlos Bay 86 3 0.0870 0.0110 0.9303

Estero Bay 87 -7 -0.2470 -0.0260 0.8047

Bold values significant at the .05 level
Turbidity Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

73

M. Turbidity

1. Background 

 Turbidity measures the amount of suspended particulate matter within the water 

column including both organic and inorganic material. Increased turbidity in estuaries 

can be a result of estuarine bottom sediments from wind and wave action, storm water 

runoff from the watershed, erosion and others. Excessive turbidity in estuaries has a 

variety of physical and biological effects, including decreased light availability for 

seagrass (Kirk 1983, McPherson and Miller 1994, Ott et al 2006), as well as potentially 

decreasing productivity, growth and survival of shellfish (Volety and Encomio 2006). 

2. Status and Trends Results 

 Turbidity summary statistics and status results from the 1998-2005 CHEVWQMN 

are given in Tables 5.26-5.28 and Figures 5.29-5.31. Turbidity levels varied significantly 

(p<0.05) over the study region and period and ranged from 0.1 to 120.00 NTU. The 

median value, 2.7 NTU, from all sites was average compared to typical Florida values 

(Hand, 2004). Estero Bay had the highest median turbidity value of 4.2 NTU and 

ranked in the 70th percentile of Florida estuaries. 

 Turbidity levels varied seasonally across the Charlotte Harbor region. For all 

sites, the median turbidity value of 2.7 NTU in the dry season was significantly higher 

(p<0.05) than the rainy season median of 2.6 NTU. Although turbidity varied seasonally 

across the entire study region, post hoc comparisons revealed only Estero Bay and 

Matlacha Pass exhibited significant (p<0.05) seasonal differences. For visual 

comparison of seasonal results, see Figure 5.30, with detailed seasonal comparisons in 

Appendix B. 

A generalized analysis comparing results to state regulatory criteria was 

conducted to characterize the status of turbidity for each site. Results are shown in 

Table 5.27. Florida Surface Water Quality Standards state that turbidity shall never 

exceed 29 NTU above natural background conditions. Due to the absence of defined 

background turbidity levels in the Charlotte Harbor region, a general comparison the 

median results for all sites plus 29 NTU (i.e. 31.7 NTU) was provided for the regulatory 

analyses. Only three samples across the study region exceeded the 31.7 NTU 

standard, at three different sites in Upper Lemon, San Carlos and Estero Bays. 

 Turbidity trends varied significantly from 1998 through 2005 in six of the nine 

estuary regions. Significant decreases (p<0.05) were detected in Upper and Lower 

Lemon Bay, Lower Charlotte Harbor, Gasparilla/Cape Haze, Pine Island Sound and 

San Carlos Bay. Rates of annual decrease ranged from approximately 0.1 to 0.3 NTU. 

For visual trend assessment, time series plots are included in Figure 5.31, with detailed 

analysis results given in Table 5.28. 

3. Discussion

 Suspended sediments within the water column come from a variety of sources 

including sediment loading from freshwater inflows, coastal erosion, resuspension from 

wave and boat action, tidal influences, and dredging. The contribution of these factors 
Turbidity Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

74

to turbidity levels varies temporally and spatially. Freshwater inflows from the Peace, 

Myakka and Caloosahatchee Rivers are primary sources of sediment loading into 

Charlotte Harbor (Hammett 1990), with nonpoint sources contributing almost 97% of the 

total suspended solids load (Squires et. al. 1997). However, resuspension of sediments 

due to wind action may be the primary cause for increased turbidity in shallow estuaries 

(de Jorge and Beusekom 1995). The degree to which each of these contributes to the 

variability of turbidity within the system is largely determined by the water depth, 

sediment type, tidal influences and stratification of the water column. 

Across the study region, turbidity values were generally average compared to 

other estuaries across the state of Florida. Turbidity was highest in Estero Bay, a 

shallow estuary, where wind and wave action may contribute to resuspension of bottom 

sediments. Although freshwater flow may carry sediments and solids into the estuary 

(Hammett 1990, Squires et al. 1997), results of this study indicate that dilution from 

inflow may be a large influence on turbidity concentrations within the study region. 

Table 5.26: Summary and status of turbidity (NTU) results for each estuary region

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 240 0.5 66.0 2.9 0.3 2.5 3 50 average

Lower Lemon Bay 296 0.5 9.7 3.1 0.1 2.6 4 50 average

Upper Charlotte 556 0.5 24.0 3.2 0.1 2.7 6 50 average

Lower Charlotte 226 0.1 21.0 2.5 0.2 2.1 1 40 average

Gasp./Cape Haze 162 0.6 30.0 3.3 0.2 2.7 6 50 average

Pine Island Sound 368 0.3 28.0 3.7 0.2 2.6 4 50 average

Matlacha Pass 221 0.1 10.5 2.5 0.1 2.1 1 40 average

San Carlos Bay 294 0.5 120.0 4.2 0.4 3.2 8 60 average

Estero Bay 319 0.1 52.0 5.6 0.3 4.2 9 70 higher than average

All Sites 2682 0.1 120.0 3.5 0.1 2.7 50 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***above average conditions < 40, 40 < average < 70, below average conditions > 70

Table 5.27: Sites with turbidity samples exceeding median (2.7 NTU) plus 29 NTU per Florida Surface Waters Criteria

Estuary Region Site # over value N % over

Upper Lemon Bay LBV003 1 66 64 108.20%

Estero Bay EBV005 1 52 65 64.04%

San Carlos Bay EBV001 1 120 66 278.55%
Turbidity Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

75

 Figure 5.29: Turbidity Box plot results for each estuary region. Outliers are not shown. 

 Figure 5.30: Seasonal turbidity Box plot results for each estuary region. Outliers are 

not shown. Dry Season Rainy Season 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.00

5.00

10.00

15.00

20.00

Turb di ity (NTU)

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.00

5.00

10.00

15.00

20.00

Turb di ity (NTU)
Turbidity Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

76

Figure 5.31: Time series plot of turbidity (NTU) for 1998 through 2005. Each line/point 

represents the monthly median from all sites in each aquatic preserve.

Upper Charlotte Lower Charlotte Cape Haze

Estero Bay San Carlos Bay Lower Lemon Bay

Upper Lemon Bay Matlacha Pass Pine Island Sound

0.00

20.00

40.00

60.00

Turbidity (NTU) 0.00

20.00

40.00

60.00

Turbidity (NTU)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

0.00

20.00

40.00

60.00

Turbidity (NTU)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

Table 5.28: Turbidity (NTU) trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept

Upper Lemon Bay 81 -80 -3.591 -0.339 0.0003 -0.1850 3.3400

Lower Lemon Bay 82 -85 -3.753 -0.353 0.0002 -0.2917 4.0670

Upper Charlotte 82 -16 -0.671 -0.066 0.5023

Lower Charlotte 82 -62 -2.834 -0.264 0.0046 -0.1000 2.5900

Gasparilla/Cape Haze 82 -69 -3.032 -0.286 0.0024 -0.2971 3.9640

Pine Island Sound 82 -65 -2.880 -0.270 0.0040 -0.2250 3.8000

Matlacha Pass 82 -34 -1.485 -0.141 0.1376

San Carlos Bay 81 -63 -2.815 -0.268 0.0049 -0.2500 4.4000

Estero Bay 82 -42 -1.826 -0.174 0.0678

Bold values significant at the .05 level
Color Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

77

N. Apparent Color

1. Background 

 Apparent color is a visual assessment of dissolved and suspended matter within 

the water column. Dissolved matter may include metal ions, humus or peat, plankton, 

aquatic vegetation, and industrial wastes (APHA 1998). Dissolved organic matter, as 

measured by apparent color, is largely the result of tannins leached from vegetation in 

upland and submerged habitats. In southwest Florida, mangroves and salt marshes are 

the primary contributors to tannins. This tannin-rich water, appearing brownish in color, 

enters the estuary primarily via freshwater inflow from major tributaries and rivers, as 

well as direct runoff from the adjacent watershed. High color, occurring at low salinities, 

is a significant reducer of light available for photosynthetic growth, primarily seagrasses 

(Kirk 1983, McPherson and Miller 1994, Ott et al. 2006). For this reason, color is an 

indicator of salinity and freshwater inflow quantity as it relates to estuarine health. 

 

2. Status and Trends Results 

Color summary statistics and status results from the 1998 - 2005 CHEVWQMN 

are given in Tables 5.29 and 5.30 and Figures 5.32-5.34. Color varied significantly 

(p<0.05) across the nine estuary regions ranging from 1 to 400 PCU. The median color 

value (25 PCU) for all sites across the Charlotte Harbor study area was average and 

ranked in the 60th percentile compared to Florida estuaries. Upper Charlotte Harbor 

had the highest color median of 50 PCU. Color concentrations in Upper Lemon Bay, 

Matlacha Pass and Estero Bay were also higher than average with median values of 30 

PCU. Lower Lemon Bay had the lowest color median value of 15 PCU, ranking in the 

50th percentile of Florida’s estuaries. 

 For all sites across the region, color concentrations were significantly higher 

during the rainy season with a median value of 40 PCU which is double the dry season 

median value of 20 PCU. Seasonal differences were observed for each estuary region, 

with differences between seasonal medians ranging from 10 PCU in Pine Island Sound, 

Lower Lemon Bay and San Carlos Bay to 30 PCU in Upper Charlotte Harbor. For visual 

assessment of seasonal differences, see Box plot results in Figure 5.33 and for detailed 

seasonal comparisons, see Appendix B. 

 Color values varied significantly during the study period from 1998 through 2005 

for seven of the nine estuary regions. Color concentrations significantly increased 

during this period in all estuary regions, except Upper Lemon Bay and Pine Island 

Sound. Rates of annual increase ranged from approximately 1 PCU in Lower Lemon 

Bay to 4 PCU in Upper Charlotte Harbor. For visual trend assessment, time series plots 

are included in Figure 5.34 with detailed analysis results given in Table 5.30. 

3. Discussion 

Apparent color across the study region was generally average with highest 

median values occurring in estuaries with greatest freshwater influence, including Upper 

Charlotte Harbor, Upper Lemon Bay, Matlacha Pass and Estero Bay. Color values 

were highest in the tidal portions of the Peace and Myakka Rivers and at sites near 

smaller freshwater tributaries. Significant seasonal differences in color concentrations 
Color Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

78

found in the CHEVWQMN results reinforce previous studies documenting that color 

concentrations are driven by freshwater influences and vary temporally as a result of 

increased flow from rainfall during the summer months (e.g. McPherson and Miller 

1987; McPherson and Miller 1994; Dixon and Kirkpatrick 1999; Doering and 

Chamberlain 1999; Tomasko and Hall 1999). Additionally, increasing trends in color 

from 1998 through 2005 correspond to decreasing salinity patterns and increased 

freshwater flow during study period. The increases in flow correspond to increases in 

rainfall associated with weather patterns that have affected the Charlotte Harbor region 

during recent years. 

 Above-average color conditions and increasing color trends, play an important 

role in characterizing estuarine health within the Charlotte Harbor region, especially as 

this relates to salinity and freshwater input. Regionally color can serve as an indicator 

of freshwater influence and is a primary constituent in water quality components 

affecting light attenuation within the water column (Kirk 1983, McPherson and Miller 

1987; McPherson and Miller 1994; Dixon and Kirkpatrick 1999; Doering and 

Chamberlain 1999; Tomasko and Hall 1999, Ott et al. 2006). In the Charlotte Harbor 

region, a better understanding is needed of the relationships between color in the 

estuaries and dissolved organic matter input from the adjacent watershed. 

Table 5.29: Summary and status of color (PCU) results for each estuary region

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries*

Median compared 

to Typical FL 

Estuary 

Percentiles**

Status Relative to 

Typical FL 

Estuaries***

Upper Lemon Bay 239 4 240 38 2 30 6 70 higher than average

Lower Lemon Bay 296 1 240 25 2 15 1 50 average

Upper Charlotte 557 4 400 70 3 50 9 80 higher than average

Lower Charlotte 226 1 140 30 2 24 5 60 average

Gasparilla/Cape Haze 162 3 120 24 1 20 3 50 average

Pine Island Sound 369 1 200 25 1 18 2 50 average

Matlacha Pass 221 1 160 37 2 30 6 70 higher than average

San Carlos Bay 294 1 160 27 1 20 3 50 average

Estero Bay 319 1 140 31 1 30 6 70 higher than average

All Sites 2683 1 400 38 1 25 60 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***lower than average < 40, 40 < average < 70,higher than average > 70
Color Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

79

 Figure 5.32: Color Box plot results for each estuary region. Outliers are not shown. 

 Figure 5.33: Seasonal color Box plot results for each estuary region. Outliers are not 

shown. Dry Season Rainy Season 

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.00

50.00

100.00

150.00

200.00

Color (PCU)

Upper Lemon Bay

Lower Lemon Bay

Upper Charlotte

Lower Charlotte

Gasparilla/Cape Haze

Pine Island Sound

Matlacha Pass

San Carlos Bay

Estero Bay

Estuary Region

0.00

100.00

200.00

300.00

Color (PCU)
Color Status and Trends from 1998 through 2005 CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

80

Figure 5.34: Time series plot of color (PCU) for 1998 through 2005. Each line/point 

represents the monthly median from all sites in each aquatic preserve.

Upper Charlotte Lower Charlotte Cape Haze

Estero Bay San Carlos Bay Lower Lemon Bay

Upper Lemon Bay Matlacha Pass Pine Island Sound

0.00

50.00

100. 00

150. 00

200. 00

Color P( CU)

0.00

50.00

100. 00

150. 00

200. 00

Color P( CU)

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

0.00

50.00

100. 00

150. 00

200. 00

Color P( CU)

05 M- AR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

05-MAR-1999

27-JAN-2001

23-DEC-2002

16-NOV-2004

Date

Table 5.30: Color (PCU) trends results

Data Points 

Read

Kendall's 

Test Statistic z

correlation 

coefficient p (2 tailed) slope intercept*

Upper Lemon Bay 81 28 1.226 0.119 0.2204

Lower Lemon Bay 82 56 2.490 0.232 0.0128 1.250 10.00

Upper Charlotte 82 57 2.509 0.237 0.0121 4.000 34.00

Lower Charlotte 82 59 2.637 0.245 0.0084 2.000 15.50

Gasparilla/Cape Haze 82 87 3.876 0.361 0.0001 2.333 10.67

Pine Island Sound 82 42 1.853 0.174 0.0638

Matlacha Pass 82 72 3.223 0.299 0.0013 3.250 17.00

San Carlos Bay 81 64 2.870 0.272 0.0041 3.333 6.67

Estero Bay 82 68 3.033 0.282 0.0024 2.500 20.00

Bold values significant at the .05 level
Water Quality Relationships: Introduction CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

81

VI. Results of Water Quality Relationships within the 

CHEVWQMN 

A. Introduction 

 Identifying relationships among water quality parameters is essential for 

understanding the dynamic biotic and abiotic interactions within the estuarine system. 

These relationships differ both spatially and seasonally, allowing for the characterization 

of both regional and temporal affects upon water quality within the Charlotte Harbor 

estuary regions. Furthermore, the presence of significant trends and above or below 

state average conditions from the CHEVWQMN results emphasizes the need to 

investigate these relationships. Nonparametric correlation analyses were conducted to 

quantify relationships between parameters of interest for both rainy and dry seasons for 

each estuary. Additional stepwise regressions were conducted to quantify the 

contribution of nutrients to changes in phytoplankton production as well as the 

contribution of light limiting parameters to changes in water clarity. A stepwise 

regression limits entry into the regression equation to parameters that contribute 

significantly to changes in the dependent variables, which are, for these analyses, 

salinity, chlorophyll a or Secchi depth. Spearman’s rho correlation coefficients range 

from -1, strong negative relationship, to 1, strong positive relationship. R2

 values are 

also given to guide interpretation of regression results. R2

 describes the amount of 

variability explained by the independent variables, the higher the R2 the more variability 

is explained. Correlation and regression results for specific water quality relationships 

are presented in tables throughout the text, with detailed results in Appendix D. 

 Water quality relationships were analyzed for four major water quality 

interactions: 1) relationships between average annual rainfall and selected parameters, 

2) the interactions between salinity and selected parameters, 3) the relationships 

between nutrients and phytoplankton productivity represented by chlorophyll a

concentrations, and 4) the relationships between light-limiting factors and water clarity 

represented by Secchi disk depths. Significant relationships were detected for many 

parameters for all estuaries collectively and for each individual estuary region in both 

the rainy and dry seasons. Although relationships between many parameters were 

significant, the strength of these relationships, as described by the correlation 

coefficient, varied and was often minimal. For this reason, when interpreting water 

quality correlations, attention should be given both to the significance of the relationship, 

as well as to the strength and direction of the relationship. 
Relationships Between Salinity and Selected Parameters CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

82

B. Relationship between Rainfall and Selected Parameters 

1. Background 

 Within aquatic systems, variations in rainfall quantities have the ability to alter 

many physical and chemical processes. Many times this variation is the result of largescale weather patterns. During the early portion of the study period, 1998-2002, 

southwest Florida experienced a drought due to the La Niña portion of an ENSO event. 

In addition, the region had entered the warming phase of an AMO event. These factors 

combined created essentially two periods within the study, with regard to regional 

hydrologic conditions. The first period, from 1998 to 2000, was typified by a decrease in 

precipitation. The later part of the study, 2001-2005, was characterized by an increase 

in rainfall. This alteration in the patterns of precipitation has the potential to influence 

water quality parameters such as: salinity, pH, while increasing runoff, nutrients, fecal 

contaminants, and turbidity. Therefore it is important to understand these relationships 

in order to monitor the health of an estuary. 

 Correlation analyses were conducted to quantify the relationship between rainfall 

and salinity, pH, nutrients, fecal coliform bacteria and factors affecting water clarity. 

These relationships create the foundation upon which the other correlations in the study 

are based. In addition, because rainfall, runoff, and land use are related, it is important 

to understand the relationships between rainfall and factors that affect water quality and 

how they may be related to land use. 

2. Results 

 Average annual rainfall was significantly and negatively correlated (correlation 

coefficient -0.86) to salinity throughout the entire region. As the quantity of rain 

increased, freshwater inputs increased and salinity decreased. This was true of all 

estuary regions, with the exception of Estero Bay. The pH within the Charlotte Harbor 

estuaries was also significantly negatively correlated (correlation coefficient -0.91). 

However, post hoc comparisons showed rainfall and pH to be significantly correlated in 

Lower Charlotte Harbor, Gasparilla/Cape Haze, Pine Island Sound and San Carlos Bay. 

See Appendix E for detailed results. 

 Nutrients were not found to be significantly correlated to rainfall within the region 

as a whole, based on the CHEVWQMN results. However, post hoc comparisons did 

show a significant correlation between total phosphorus and rainfall within Upper 

Charlotte Harbor (correlation coefficient 0.88). No other significant relationships were 

found for nutrients and rainfall within the region, nor where there any relationships with 

fecal coliform bacteria. See Appendix E for detailed results. 

 Within the Charlotte Harbor estuaries, no significant correlations were found for 

factors affecting water clarity and rainfall. However, post hoc comparisons did show 

color to be significantly correlated to rainfall for both Pine Island Sound and Matlacha 

Pass (correlation coefficients 0.80 and 0.71, respectively). See Appendix E for detailed 

results. 
Relationships Between Salinity and Selected Parameters CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

83

3. Discussion 

 Average annual rainfall was significantly and negatively correlated to changes in 

salinity and pH throughout the study period and region. Results varied spatially, 

particularly for pH for those estuary regions with direct connections to the Gulf of 

Mexico, i.e. Cape Haze/Gasparilla Sound, San Carlos Bay, etc. These results suggest 

that rainfall has a greater impact on pH for those estuary regions with limited influence 

from freshwater tributaries. Salinity decreased as rainfall increased for the entire 

region, with the exception of Estero Bay. In Estero Bay, with relatively small tributaries 

feeding into it, rainfall may exert less influence over salinity regimes. Upper Charlotte 

Harbor was the only estuary region to show a positive correlation between TP and 

rainfall. This indicates that with increased rainfall, the runoff carries the phosphate-rich 

soils within the watershed to the estuary region while flow resuspends the sediments, 

creating an increase in TP loads. In addition, due to the relationship between color and 

freshwater flow, significant increases in color can be explained for both Pine Island 

Sound and Matlacha Pass by the increased rainfall from 2001 to 2005. 
Relationships Between Salinity and Selected Parameters CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

84

C. Relationship between Salinity and Selected Parameters 

1. Background 

As previously discussed, salinity has a major influence on many chemical, 

physical and biological estuarine processes. Natural variability in salinity occurs tidally, 

seasonally and as a function of increased flow from major tributaries and rivers, as well 

as from runoff and the degree of mixing within the water column. Artificial alterations of 

natural hydrologic regimes such as altering the flow of major tributaries can also have 

serious deleterious effects on water quality and the biological communities that are 

adapted to narrow salinity ranges. For these reasons, understanding the potential 

effects of changes in salinity on other water quality parameters is essential in describing 

the health of the Charlotte Harbor estuary regions. 

 Correlation analyses were conducted to quantify the relationships between 

salinity and parameters that vary as a result of changes in salinity, including color, 

nutrients, turbidity and fecal coliform bacteria. Strong relationships between salinity and 

these variables help characterize the nature of these physical and chemical interactions 

within estuarine waters. Additionally, because decreases in salinity are related to 

increased flow from the watersheds, strong relationships between salinity and other 

parameters may link watershed uses and influences to the water quality within the 

estuaries. 

2. Results 

 Salinity was significantly negatively correlated (correlation coefficient -0.71) to 

color across the Charlotte Harbor estuaries. As salinity decreased, color increased for 

both seasons and for all estuary regions. The negative correlation between color and 

salinity was strongest during the rainy season (correlation coefficient -0.72) and in 

estuaries with greater salinity variability, including Upper and Lower Lemon Bay, Upper 

Charlotte Harbor, and Estero Bay. See Figure 6.1 with detailed results in Appendix D. 

 Nitrogen and phosphorus concentrations were significantly correlated (p<0.05) to 

salinity, a factor which can influence nutrient concentrations. Concentrations of TP 

were also significantly and negatively correlated with salinity. Total nitrogen 

concentrations decreased along an increasing salinity gradient, although this 

relationship was weaker than for salinity and phosphorus. The correlation between 

nitrogen and salinity was stronger during the rainy season (-0.37) and in estuaries with 

strong freshwater influence including Upper Lemon Bay (-0.39) and Upper Charlotte 

Harbor (-0.44). See Figures 6.2 and 6.3 and Appendix D for detailed results. 

 Salinity was also significantly and negatively correlated to turbidity (correlation 

coefficient 0.20), although the relationship was weaker compared to other significant 

salinity correlations. However, post hoc comparisons revealed that turbidity levels were 

not significantly correlated to salinity in regions with strong freshwater influence, such as 

Upper Charlotte Harbor and Matlacha Pass. See Figure 6.4 and Appendix D for 

detailed results. 
Relationships Between Salinity and Selected Parameters CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

85

 Fecal coliform was significantly and negatively correlated with changes in salinity. 

As salinity increased, fecal coliform decreased across the entire study region 

(correlation coefficient -0.34) and for both the rainy (correlation coefficient -0.40) and dry 

seasons (correlation coefficient -0.32). However, further analyses revealed that coliform 

was not significantly correlated to salinity in estuary regions with minimal occurrence of 

fecal bacteria, including Lower Charlotte Harbor, Gasparilla Sound/Cape Haze, Pine 

Island Sound, Matlacha Pass, and San Carlos Bay. See Figure 6.5 and Appendix D for 

detailed analyses. 

3. Discussion 

 Salinity was significantly and negatively correlated to changes in color, nutrients 

(including both nitrogen and phosphorus), turbidity and fecal coliform bacteria. Results 

varied both seasonally and spatially as a possible result of increases in salinity 

variability during the rainy season. Results varied in some estuary regions as well, 

particularly Upper Lemon Bay, Upper Charlotte Harbor and Matlacha Pass. These 

results indicate that increases in color are significantly related to salinity declines 

resulting from increases in tannin-rich freshwater inflows to the estuary. Similar to 

previous findings, significant decreases in nutrients and bacteria, along an increasing 

salinity gradient, may be an indicator of the persistence of nutrients (e.g. Hammett 

1990) and fecal coliform bacteria (e.g. Fujioka et al. 1981) in a tidally influenced system. 

In addition, due to the strong relationship between color, turbidity and salinity, a 

decreasing trend in turbidity, as well as an increasing color trend from 1998 through 

2005, could be explained by a significantly decreasing trend in salinity across the study 

region. 
Relationships Between Salinity and Selected Parameters CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

86

@ Rainy Season: -0.7217

> Dry Season: -0.6957

Correlation Coefficients

0.00 10.00 20.00 30.00 40.00

Salinity (ppt)

0.00

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200.00

300.00

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Figure 6.1: Scatter plot results of color as predicted by salinity. 

@ Rainy Season: -0.4890

> Dry Season: -0.4121

Correlation Coefficients

0.00 10.00 20.00 30.00 40.00

Salinity (ppt)

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Figure 6.2: Scatter plot results of total phosphorus as predicted by salinity. 
Relationships Between Salinity and Selected Parameters CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

87

@ Rainy Season: -0.3671

> Dry Season: -0.3188

Correlation Coefficients

0.00 10.00 20.00 30.00 40.00

Salinity (ppt)

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 Figure 6.3: Scatter plot results of total nitrogen as predicted by salinity. 

@ Rainy Season: 0.1828

> Dry Season: 0.2040

Correlation Coefficients

0.00 10.00 20.00 30.00 40.00

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Figure 6.4: Scatter plot results of turbidity as predicted by salinity.
Relationships Between Salinity and Selected Parameters CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

88

@ Rainy Season: -0.4033

> Dry Season: -0.3157

Correlation Coefficients

0.00 10.00 20.00 30.00 40.00

Salinity (ppt)

0.00

500.00

1000.00

1500.00

Fecal Colifo

mr Bac

et r ai (cfu/100mL)

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Figure 6.5: Scatter plot results of fecal coliform bacteria as predicted by salinity. 
Nutrient and Chlorophyll a Relationships CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

89

D. Nutrient and Chlorophyll a Relationships 

1. Background 

 In the Charlotte Harbor region, nitrogen and phosphorus loadings have been 

shown to significantly increase phytoplankton production and harmful algal blooms, 

thereby affecting chlorophyll a concentrations, resulting in decreased water clarity. For 

these reasons, chlorophyll a is a useful tool in characterizing nutrient enrichment in the 

Charlotte Harbor estuaries (e.g. Doering et al 2006). Determining the effects of 

nutrients on chlorophyll a concentrations as an indicator of phytoplankton production is 

essential in managing the water quality of the nine estuary regions. Quantifying the 

contribution of nitrogen and/or phosphorus to changes in chlorophyll a may allow 

resource management efforts to target either nutrient as a means to reduce chlorophyll 

a levels. 

2. Results 

 The relationship between nutrients and chlorophyll a varied seasonally and 

spatially across the nine estuary regions during the study period. It should be noted, 

however, that the strength of these relationships was minimal. Across the study area, 

chlorophyll a concentrations significantly increased as both total nitrogen and TP 

increased. For all sites, the relationship between TP and chlorophyll a (correlation 

coefficient 0.28) was slightly stronger than nitrogen correlations (correlation coefficient 

0.23) and changes in phosphorus levels explained the most variability (R2 ~10%) in 

chlorophyll a. However, during the rainy season, total nitrogen (~4%) contributed 

statistically to most of the changes in chlorophyll a, while phosphorus (~16%) 

statistically contributed the most in the dry season. Total nitrogen was the only 

parameter maximizing explained variation in chlorophyll a concentrations in Upper and 

Lower Lemon Bay (4%), Pine Island Sound (~7%) and Estero Bay (~3%). Alternately, 

in Upper Charlotte Harbor phosphorus concentrations (~13%) statistically contributed 

most to changes in chlorophyll a. Neither nutrient contributed significantly to changes in 

chlorophyll a concentrations in Lower Charlotte Harbor, Cape Haze, Matlacha Pass and 

San Carlos Bay. For visual reference of nutrient relationships see Figures 6.6 and 6.7, 

with detailed results for each estuary regions and season in Appendix D. For 

regression results, see Table 6.1. 

3. Discussion 

 Over the study region, phosphorus maximized the explained variability in 

chlorophyll a concentrations, although a detailed post hoc analysis revealed that 

nutrient relationships varied both seasonally and spatially. Montgomery et al (1991) 

stated that nitrogen is the known limiting nutrient in the Charlotte Harbor estuaries, 

although relationships between nutrients and phytoplankton production vary spatially 

and over time. However, the results of this study fail to indicate conclusively that 

nitrogen is the primary nutrient limiting chlorophyll a concentrations across the study 

region from 1998-2005. As a result, a stronger observed relationship between 

phosphorus and chlorophyll a may be more indicative of: 1) the seasonal, temporal and 

spatial variability of the relationship between nutrients and phytoplankton production; 
Nutrient and Chlorophyll a Relationships CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

90

and 2) an inability to accurately quantify volatile nitrogen components within the water 

column. Therefore, management activities aimed at reducing phytoplankton, via 

nutrient reductions, should consider the variability of these relationships within the 

Charlotte Harbor estuaries. 
Nutrient and Chlorophyll a Relationships CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

91

@ Rainy Season: 0.2537

> Dry Season: 0.1040

Correlation Coefficients

0.000 25.000 50.000 75.000 100.000

Chlorophyll a (ug/L)

0.000

1.000

2.000

3.000

4.000

T

otal Nitrog

en (p

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Figure 6.6: Scatter plot results of chlorophyll a as predicted by total nitrogen. 

@ Rainy Season: 0.2412

> Dry Season: 0.3020

Correlation Coefficients

0.000 25.000 50.000 75.000 100.000

Chlorophyll a (ug/L)

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Figure 6.7: Scatter plot results of chlorophyll a as predicted by total phosphorus.
Nutrient and Chlorophyll a Relationships CH

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

92 

Table 6.1: Stepwise regression results of chlorophyll a as predicted by total nitrogen and total phosphorus

Model 

Order1 Parameter F R R2 R2 Change Adjusted R2 SE 

1 TP 212.872 0.322 0.104 0.104 7.459 4.688 + 2 TP, TN 181.843 0.345 0.119 0.015 0.118 7.398 2.754 + 1 TP 227.979 0.405 0.164 0.163 6.900 3.577 + 2 TP, TN 218.787 0.413 0.171 0.007 0.169 6.876 1.946 + 1 TN 25.734 0.192 0.037 0.036 8.091 4.719 + 2 TN, TP 15.501 0.227 0.051 0.015 0.049 8.036 4.669 + 1 TP 58.945 0.362 0.131 0.129 9.436 4.841 + 2 TP, TN 47.747 0.394 0.155 0.024 0.151 9.315 1.978 + 

1Only parameters that contribute significantly (p<.05) are added to the regression equation

*In Lower Charlotte Harbor, Gasparilla/Cape Haze, Matlacaha Pass and San Carlos Bay nitrogen or phosphorus did not contribute significantly to 

Pine Island Sound

Estero Bay

1 TN 16.383 0.258 0.0661

Upper Charlotte Harbor

All

Dry Season

Rainy Season

Upper Lemon BayLower Lemon Bay

1 TN 7.441 0.202 0.041 0.035 8.500 5.268 + 1 TN 9.546 0.206 0.043 0.038 7.083 2.681 + 

0.062 5.931 3.239 + 

TN 7.296 0.182 0.033 0.028 8.556 2.697 + 
Relationships Between Light Limiting Parameters CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

93 

E. Relationships between Light Limiting Parameters 

1. Background 

 In the Charlotte Harbor region, changes in water clarity can be attributed to 

fluctuations in dissolved organic matter and suspended particulates such as 

phytoplankton (Kirk 1983, McPherson and Miller 1987, McPherson and Miller 1994, 

Dixon and Kirkpatrick 1999, Ott et. al. 2006). Increases in color, turbidity and 

chlorophyll a will result in increased light attenuation within the water column. Water 

clarity in estuarine systems is essential for submerged aquatic plant growth and depth 

distribution of seagrass beds (Tomasko and Hall 1999)., As a result, characterizing the 

relationships between light limiting parameters and water clarity is important for 

seagrass management within the Charlotte Harbor estuary regions as well as the 

implementation of numeric water quality targets for this region (Corbett and Hale 2006). 

 The relationships between water clarity, as described by Secchi depth, and light 

limiting parameters including apparent color, turbidity, and chlorophyll a, were 

examined. Correlation analyses were conducted to describe the strength and 

significance of relationships between these light-limiting parameters and clarity, as well 

as to characterize the relationships between these light-limiting factors. Additional 

stepwise regression analysis was conducted to quantify the effects of light-limiting 

parameters on changes in water clarity. These analyses were performed separately for 

each season and estuary to demonstrate the seasonal and spatial variability of these 

relationships. Results are provided in both tables and figures throughout the text, with 

detailed results provided in Appendix D. 

2. Results 

 Initial analyses of the relationships between light limiting factors were conducted 

to evaluate if covariance exists between chlorophyll a, turbidity and color, in addition to 

the cumulative contribution of these factors to changes in water clarity. However, it 

should be noted that chlorophyll a and turbidity are components of color. Chlorophyll a 

concentrations were positively and significantly correlated to color (correlation 

coefficient 0.32) and turbidity (correlation coefficient 0.19). The relationship between 

color and chlorophyll a was strongest during the dry season (correlation coefficient 0.34) 

but was not significant in Upper Lemon Bay or Estero Bay. Chlorophyll a was not 

significantly correlated with turbidity in Upper Charlotte Harbor or San Carlos Bay. 

Although color and turbidity were significantly and positively correlated (correlation 

coefficient 0.04) for the entire study duration and across all sites, further analysis 

showed that the relationship was not significant during the dry season and in Lower 

Lemon Bay, Lower Charlotte Harbor, Gasparilla/Cape Haze, Pine Island Sound, San 

Carlos Bay and Estero Bay. For visual reference of relationships between light limiting 

factors, see Figures 6.8-6.10, with detailed results for each estuary region and season 

in Appendix D. 

 Color was the primary factor limiting water clarity across all sites and seasons (R2

=0.21). The addition of chlorophyll a and turbidity maximized the total variability in the 

regression model, although increased explained variation was minimal (change in R2

=0.02 and change in R2 =0.03, respectively). In the rainy season, color and chlorophyll 

a (R2 ~0.3) were the only parameters that contributed significantly to changes in Secchi 
Relationships Between Light Limiting Parameters CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

94 

depth. Alternately, during the dry season, color (R2 =0.14), followed by the addition of 

turbidity, maximized the variation in Secchi depth. 

 The primary constituent controlling changes in water clarity varied spatially 

across the region. Color explained the most variation in Secchi depth in Upper (28%) 

and Lower Charlotte Harbor (35%), Gasparilla/Cape Haze (5%), San Carlos Bay (7%) 

and Matlacha Pass (32%). Turbidity was the primary factor influencing changes in 

water clarity in Estero Bay (30%), Pine Island Sound (22%), Lower Lemon Bay (16%) 

and Upper Lemon Bay (10%). The addition of turbidity and chlorophyll a into the 

regression models for each varied across the region although the additional explained 

variation in clarity was minimal. See Table 6.2 for detailed regression results and 

Figures 6.11-6.13 for visual comparison of water clarity as predicted by color, 

chlorophyll a, and turbidity, with detailed results in Appendix D. 

3. Discussion 

 Across the Charlotte Harbor region, with the exceptions of Estero Bay, Pine 

Island Sound and Upper and Lower Lemon Bay, and across the study period, color was 

the primary contributor in changes in water clarity. The contributions of turbidity and 

chlorophyll a varied spatially and seasonally. However, these results indicate that 

turbidity is the primary component of light attenuation in estuary regions with 1) lower 

than average regional color conditions, a function of minimal freshwater influence in 

areas like Pine Island Sound and Lower Lemon Bay or 2) above average turbidity 

conditions in shallow estuaries such as Upper Lemon Bay and Estero Bay. 

 These results indicate that management activities aimed at increasing light 

availability, primarily for seagrass growth, should consider both the spatial and seasonal 

variability of these light-limiting factors. As previously discussed, a better understanding 

is needed of the relationships between clarity, color and the effects of dissolved organic 

matter from freshwater flow and watershed runoff. Additional consideration should be 

given to the effects of watershed influences and estuarine processes affecting lightlimiting factors. Specifically, increases in color, turbidity and chlorophyll a 

concentrations can result from: 1) freshwater inputs from major rivers including the tidal 

Peace, Myakka and Caloosahatchee Rivers, as well as from smaller tributaries 

(McPherson and Miller 1987, McPherson and Miller 1990; Dixon and Kirkpatrick 1999; 

Doering and Chamberlain 1999, Tomasko and Hall 1999; Doering et. al. 2006); 2) 

resuspension of estuary bed sediments or particulates (McPherson and Miller 1987); 

and 3) increases in nutrient and sediment loads from point source and non-point source 

watershed runoff (Doering and Chamberlain 1999, Hammett 1990). 
Relationships Between Light Limiting Parameters CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

95 

@ Rainy Season: 0.1359

> Dry Season: 0.3370

Correlation Coefficients

0.00 100.00 200.00 300.00 400.00

Color (PCU)

0.000

25.000

50.000

75.000

100.000

Ch ol rophylla (ug L/ )

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Figure 6.8: Scatter plot results of chlorophyll a as predicted by color. 

@ Rainy Season: 0.0680

> Dry Season: 0.1870

Correlation Coefficients

0.000 25.000 50.000 75.000 100.000

Chlorophyll a (ug/L)

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Figure 6.9: Scatter plot results of chlorophyll a as predicted by turbidity. 
Relationships Between Light Limiting Parameters CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

96 

@ Rainy Season: 0.0682

> Dry Season: 0.0330

Correlation Coefficients

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Figure 6.10: Scatter plot results of turbidity as predicted by color. 

@ Rainy Season: -0.5851

> Dry Season: -0.2719

Correlation Coefficients

0.00 1.00 2.00 3.00 4.00

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Figure 6.11: Scatter plot results of Secchi depth as predicted by color.
Relationships Between Light Limiting Parameters CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

97 

@ Rainy Season: -0.2178

> Dry Season: -0.4800

Correlation Coefficients

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Figure 6.12: Scatter plot results of Secchi depth as predicted by turbidity. 

@ Rainy Season: -0.3050

> Dry Season: -0.3270

Correlation Coefficients

0.00 1.00 2.00 3.00 4.00

Secchi Depth (m)

0.000

25.000

50.000

75.000

100.000

Ch ol rophylla (ug L/ )

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Figure 6.13: Scatter plot results of Secchi depth as predicted by chlorophyll a. 
Relationships Between Light Limiting Parameters CH

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

98 

Table 6.2: Stepwise regression results of secchi as predicted by color, turbidity and chlorophyll a 

Model 

Order1 Parameter F R R2 R2 Change Adjusted R2 SE

1 Color 313.385 0.458 0.210 0.210 0.209 0.5242 Color, Chla 37.218 0.484 0.234 0.024 0.233 0.5163 Color, Chla , Turbidity 48.080 0.514 0.236 0.030 0.263 0.5061 Color 105.842 0.376 0.142 0.142 0.140 0.5552 Color, Turbidity 177.742 0.573 0.328 0.187 0.326 0.4921 Color 199.351 0.521 0.271 0.271 0.270 0.4822 Color, Chla 36.954 0.565 0.318 0.047 0.316 0.4661 Turbidity 9.432 0.316 0.100 0.100 0.089 0.2052 Turbidity, Color 7.305 0.415 0.172 0.072 0.152 0.1981 Turbidity 24.127 0.393 0.155 0.155 0.148 0.3482 Turbidity, Color 21.118 0.521 0.272 0.117 0.261 0.3241 Color 122.718 0.531 0.282 0.282 0.279 0.3132 Color, Turbidity 9.298 0.550 0.302 0.021 0.298 0.3091 Color 39.417 0.595 0.354 0.354 0.345 0.7162 Color, Turbidity 10.254 0.660 0.435 0.082 0.419 0.6743 Color, Turbidity, Chla 6.242 0.694 0.482 0.046 0.459 0.6501 Color 5.782 0.221 0.049 0.049 0.040 0.4462 Color, Turbidity 4.810 0.296 0.088 0.039 0.072 0.4391 Turbidity 43.271 0.473 0.224 0.224 0.219 0.5602 Turbidity, Color 16.370 0.548 0.301 0.077 0.291 0.5331 Color 78.572 0.563 0.317 0.317 0.313 0.4682 Color, Turbidity 10.174 0.597 0.356 0.039 0.349 0.456

San Carlos Bay 1 Color 19.968 0.258 0.067 0.067 0.063 0.510

1 Turbidity 67.604 0.549 0.301 0.301 0.297 0.3482 Turbidity, Color 0.971 0.553 0.305 0.004 0.296 0.348

1Only parameters that contribute significantly (p<.05) are added to the regression equation

Estero Bay 1.570 - 0.058*turbidity

1.740 - 0.064*turbidity - 0.003*c

Matlacha Pass 2.216 - 0.011*color

2.340 - 0.009*color - 0.113*turb1.713 - 0.006*color

Gasparilla/ Cape 

Haze

1.652 - 0.005*color1.952 - 0.007*color - 0.065*turb

Pine Island Sound 1.719 - 0.061*turbidity

1.995 - 0.070*turbidity - 0.008*c

Upper Charlotte 

Harbor

1.266 - 0.003*color1.339 - 0.003*color - 0.024*turb

Lower Charlotte 

Harbor

2.531 - 0.017*color2.805 - 0.017 color - 0.095*turbi2.923 - 0.015*color - 0.086*turb

Upper Lemon Bay 1.029 - 0.039*turbidity

1.164 - 0.053*turbidity - 0.001*c

Lower Lemon Bay 1.588 - 0.063*turbidity

1.740 - 0.074*turbidity - 0.004*c

Dry 1.650 - 0.006*color

1.667 - 0.006*color - 0.005*turb

Rainy 1.560 - 0.005*color

1.669 - 0.005*color - 0.015*chlaRegression Equation

All

1.600 - 0.005*color 1.658 - 0.005*color - 0.010* chla

1.673 - 0.005*color - 0.010*chla 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

99

VII. Summaries of Status and Trends Results for each 

Estuary 

A. Introduction 

Water quality status and trends were characterized for eleven parameters from 

1998 through 2005 across the Charlotte Harbor and Estero Bay Aquatic Preserves. 

Across the region, 48 sampling sites were grouped into nine estuary regions and 

analyzed in this report. This section characterizes water quality conditions for each 

estuary region based on CHEVWQMN results. An additional summary of influences 

from the adjacent watersheds is provided based on the land uses and vegetative cover 

as described by the CHNEP’s Synthesis of Existing Information (1999). Management 

considerations are also provided based on the unique hydrologic conditions and 

interactions within each estuary. 

 For this summary, the nine estuary regions are grouped based on Aquatic 

Preserve boundaries and watershed influences into five Aquatic Preserve management 

areas, including: Lemon Bay, Gasparilla Sound-Charlotte Harbor and Cape Haze, Pine 

Island Sound and Matlacha Pass, San Carlos Bay and Estero Bay. Lemon Bay Aquatic 

Preserve includes both the Upper and Lower Lemon Bay estuary regions. Gasparilla 

Sound-Charlotte Harbor Aquatic Preserve includes the Gasparilla/Cape Haze, Upper 

Charlotte Harbor and Lower Charlotte Harbor estuary regions. Pine Island Sound and 

Matlacha Pass were grouped because both are affected by the same watershed basin. 

A summary of the San Carlos Bay estuary region is also included even though the sites 

and waterbody are not within the Aquatic Preserves. 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

100

B. Lemon Bay Aquatic Preserve 

Including: Upper Lemon Bay and Lower Lemon Bay Estuary Regions 

1. Background 

Lemon Bay Aquatic Preserve extends from Alligator Creek in south Sarasota 

County to the Boca Grande Bridge. The Bay is separated from the Gulf of Mexico by a 

series of barrier islands. There are seven tributaries (Alligator, Forked, Gottfried, 

Ainger, Oyster, Buck and Lemon Creeks), two Gulf passes (Stump Pass and Little 

Gasparilla) and connections to the Gulf of Mexico through the Venice Bypass Canal to 

the north and Placida Harbor to the south. The aquatic preserve boundary follows the 

mean high waterline of the Bay and the tributaries upstream to SR 776/SR 775. Lemon 

Bay is approximately 24 km (~15 mi) long and averages 1 km (~3/4 mile) wide, with an 

area of 31 km2

 (7,667 acres). The Bay is narrow and shallow, averaging 1.8 m deep at 

mean high water. Within the estuary, the largest submerged habitat is seagrass, 

comprising over 11 km2

 (2,700 acres) growing to approximately 1.7 m deep. The 

Aquatic Preserve includes two counties (Sarasota and Charlotte) and the urban areas of 

South Venice, Englewood and Placida. 

 The watershed for Lemon Bay extends downstream from the headwaters of the 

seven tributaries in Sarasota and Charlotte Counties and is approximately 184 km2

(45,500 acres) in size. The 1990 and 2010 projected land uses in the watershed are 

shown in Table 7.1.The ratio of watershed land area to open water estuary area is 

approximately 6:1. Based on the 1990 data, the largest land use in the watershed is 

urban (26%), followed by rangeland (24%) and upland forest (20%), with very little 

agriculture (2%). Of the urban area, the majority is in residential use located adjacent to 

the estuary and tributaries. The most significant projected change in future land use is 

a very large increase (>240%) in residential acres. There are approximately 37 

domestic wastewater discharges, five industrial wastewater discharges, three public 

water supplies and several industrial water supplies permitted within the Lemon Bay 

watershed. There is also a high demand for golf course and landscape irrigation 

(CHNEP 1999). 

2. Water Quality Status and Trends Results in Upper Lemon Bay 

In the Upper Lemon Bay region, CHEVWQMN results indicated generally below 

average water quality conditions and ranked below average compared to other 

estuaries in the Charlotte Harbor region as well as other estuaries across the state. 

Upper Lemon Bay ranked in the 70th, or greater, percentile of Florida estuaries for all 

nutrients and fecal coliform bacteria, in addition to ranking in the bottom 10th percentile 

for DO. Results showed frequent exceedances of Florida Surface Water Standards for 

DO, chlorophyll a, fecal coliform bacteria and turbidity. Trends in the Upper Lemon Bay 

region indicate a decrease in TKN, turbidity, salinity and pH, and an increase in DO. 

The primary factors contributing to light attenuation are turbidity and color. Water 

quality status and trends results for Upper Lemon Bay are shown in Table 7.2 

 Sampling site LBV001 exhibited the most degraded water quality in Upper 

Lemon Bay possibly affecting the collective results for the region. The site had one of 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

101

the greatest percentages of DO values that were less than 4.0 and 5.0 mg/L, as well as 

the only site to have fecal coliform bacteria exceedances greater than both 400 and 800 

cfu/100mL. The site is located near a smaller tributary and is the northernmost site in 

Upper Lemon Bay. Site LBV003 was the only site within the region to have turbidity 

(greater than 31.7 NTU) exceedances. Site LBGOT2, a site located about 3 km (2 mi) 

upstream in Gottfried Creek, also exhibited above average color, fecal coliform bacteria 

and total phosphorus values. Site specific water quality status results are shown in 

Appendix A. 

3. Water Quality Status and Trends Results for Lower Lemon Bay 

Water quality in Lower Lemon Bay ranged from above average to below average 

depending on the parameter of interest. The pH and salinity within the region were 

relatively high with median values of 8.3 and 33.5, respectively, ranking in the top 90th

and 100th percentiles, respectively, of Florida estuaries. Secchi depth was above 

average in Lower Lemon Bay ranking in the 70th percentile of Florida estuaries. DO 

concentrations were typically low in Lower Lemon Bay, ranking in the 20th percentile of 

all Florida estuaries and frequently below Florida Surface Water Standards of 4.0 and 

5.0 mg/L. Significant trends include decreasing TKN and turbidity and increasing color. 

As in Upper Lemon Bay, turbidity and color are the primary light attenuating parameters. 

Water quality status and trends results for Lower Lemon Bay are shown in Table 7.3 

 Site LBV006 had the lowest water quality status in general of all sites in Lower 

Lemon Bay. LBV006, located in Buck Creek, had frequent exceedances of regulatory 

criteria including dissolved oxygen, chlorophyll a, and fecal coliform bacteria. Fecal 

coliform bacteria levels for sites LBV006 and LBANG1 were above the typical Florida 

estuarine water quality average, ranking in the 100th percentile of Florida estuaries. Site 

LBV007 generally exhibited the highest water quality, with frequent status rankings 

below the 50th percentile of Florida estuaries and with the smallest percent of regulatory 

exceedances. Site specific water quality status results are shown in Appendix A. 

4. Discussion 

 CHEVWQMN results indicate below-average water quality across the Lemon Bay 

region, particularly in tributaries located in Upper Lemon Bay. Below average DO 

conditions that frequently exceeded Florida Surface Water Criteria are of one of the 

most critical water quality issues across Lemon Bay. Regulatory exceedances of fecal 

coliform bacteria in the region, particularly near tributaries, are additional concerns. 

Results, however, indicate that fecal coliform bacteria exceedance events were isolated, 

indicating that causes of increased bacteria are site- and event-specific. In the Lemon 

Bay estuary, turbidity explained the most variability in water clarity. 

 Effective resource management goals for Lemon Bay Aquatic Preserve should 

focus on improving DO, fecal coliform, turbidity and chlorophyll a levels in the estuary. 

Reducing turbidity levels would contribute to improving water clarity, thereby enhancing 

seagrass growth. Potential natural and anthropogenic sources of turbidity, such as 

wind-driven, boating-related, and storm-water velocity, should be investigated and 

quantified. Additionally, elevated nutrient and fecal coliform bacteria levels associated 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

102

with growing urban land uses, such as septic systems and stormwater runoff, should be 

identified, quantified, prioritized and remediated. 

Table 7.1: Land uses in the Lemon Bay watershed

Projected

Land Use1, 2, 3, 4 acres % acres % Change

Urban

 Residential 10,428 23% 38,051 84%

 Commercial/Industrial/Institutional 1,313 3% 2,304 5%

 SubTotal 11,741 26% 40,355 89% 244%

Mining 286 1% 0 0% -100%

Agriculture

 Row Crops/Groves/Nursery 186 0%

 Pasture/Feedlot 749 2%

 Sub Total 935 2% 529 1% -43%

Open Land, Wetlands, Water

 Forest/Range/Barren/Preserve 20,461 45% 4,614 10%

 Wetlands 4,641 10%

 Open Water 7,434 16%

 Sub Total 32,536 71% 4,614 10% -86%

TOTAL 45,498 100% 45,498 100%

1

Includes Lemon Bay Aquatic Preserve.

2

 Includes Upper Lemon Bay and Lower Lemon Bay Estuary Regions.

3 Includes Lemon Bay Watershed.

4

 From "Synthesis of Existing Information", Charlotte Harbor National Estuary Program 1999.

 Based on SWFWMD, SFWMD and Southwest Florida Regional Planning Council data.

1990 2010 Projected
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

103

Table 7.2: Status and Trends Summary for Upper Lemon Bay

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries1

Median compared 

to Typical FL 

Estuary 

Percentiles2

Status Relative to 

Typical FL 

Estuaries

Trend 

Results3

Secchi (m) 161 0.4 1.6 0.9 0.0 0.9 1 40 average

Temp (deg. C) 381 12.0 32.0 23.7 0.2 24.5 3 50 average

DO (mg/L) 373 1.0 8.8 4.1 0.1 3.9 1 10 lower than average ↑

pH 377 7.2 8.8 8.0 0.0 8.0 2 60 average ↓

Salinity (ppt) 376 0.0 40.7 22.4 0.6 25.3 3 50 average ↓

TN (ppm) 219 0.075 2.750 1.035 0.031 1.0 9 70 higher than average ↓4

TP (ppm) 228 0.010 1.080 0.199 0.007 0.2 8 70 higher than average

Chl a (ug/L) 209 0.50 52.30 9.20 0.60 6.3 9 50 average

Coliform (cfu/100mL) 252 1 1156 98 10 35.0 9 80 higher than average

Turbidity (NTU) 240 0.5 66.0 2.9 0.1 2.5 3 40 average ↓

Color (PCU) 239 4 240 38 2 30.0 6 60 average

1 Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

2 Median value compared to typcial Florida estuarine water quality percentile distributions (Hand in press 2004)

3

↓ Significantly decreasing at the .05 level 3

↑ Significantly increasing at the .05 level

4 Trend results of total Kjeldahl nitrogen
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

104

Table 7.3: Status and Trends Summary for Lower Lemon Bay

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries1

Median compared 

to Typical FL 

Estuary 

Percentiles2

Status Relative to 

Typical FL 

Estuaries

Trend 

Results3

Secchi (m) 230 0.5 3.3 1.3 0.0 1.3 4 60 average

Temp (deg. C) 525 10.0 32.0 23.6 0.2 24.0 1 50 average

DO (mg/L) 515 0.6 8.2 4.7 0.1 4.8 3 10 lower than average

pH 520 7.2 9.0 8.3 0.0 8.3 8 100 higher than average

Salinity (ppt) 518 2.1 40.7 31.7 0.3 33.5 9 100 higher than average

TN (ppm) 265 0.075 2.560 0.790 0.025 0.767 5 50 average ↓4

TP (ppm) 275 0.010 0.420 0.084 0.003 0.070 4 40 average

Chl a (ug/L) 259 0.01 79.46 5.55 0.42 3.92 4 30 lower than average

Coliform (cfu/100mL) 302 1 800 41 5 8 6 60 average

Turbidity (NTU) 296 0.5 9.7 3.1 0.1 2.6 4 40 average ↓

Color (PCU) 296 1 240 25 2 15 1 40 average ↑

1 Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

2 Median value compared to typcial Florida estuarine water quality percentile distributions (Hand in press 2004)

3

↓ Significantly decreasing at the .05 level 3

↑ Significantly increasing at the .05 level

4 Trend results of total Kjeldahl nitrogen
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

105

C. Gasparilla Sound–Charlotte Harbor and Cape Haze Aquatic 

Preserves 

Including Gasparilla/Cape Haze, Upper Charlotte Harbor and Lower Charlotte 

Harbor Estuary Regions 

1. Background 

 The Gasparilla Sound-Charlotte Harbor and Cape Haze Aquatic Preserves are 

discussed together in the following section because the two aquatic preserves share a 

common estuary and watershed. Together, the two aquatic preserves extend from the 

Myakka and Peace River mouths southwest to Boca Grande Pass. The boundary of 

the aquatic preserves follows the mean high water line of the Harbor and tributaries 

upstream to tidal influence. Additionally, the aquatic preserves are bounded in Punta 

Gorda by the US 41 S Bridge, in El Jobean by the SR776 Bridge, in Placida by the Boca 

Grande causeway, and in the south by the north tips of Cayo Costa and Pine Island. 

Charlotte Harbor is approximately 26 km (16 mi) long and 19 km (12 mi) wide at its 

maximum extents, covering over 368 km2

 (91,052 acres) of submerged waters. 

Charlotte Harbor proper is the largest and deepest of the local estuaries, exceeding 6 m 

deep in the central depressions and 15 m deep at Boca Grande Pass. The two major 

tributaries are the Myakka and Peace Rivers, along with several smaller tributaries, 

including Alligator, Catfish and Whidden Creeks and Yucca Pen. Charlotte Harbor and 

Cape Haze Aquatic Preserves are located in Charlotte and Lee Counties, adjacent to 

the communities of Punta Gorda, Port Charlotte, Placida and Boca Grande. 

 Seagrass is a critical submerged habitat within the Gasparilla Sound-Charlotte 

Harbor and Cape Haze Aquatic Preserves, occurring along the shallow shoreline areas, 

comprising over 63 km2 (15,678 acres). Throughout the estuary, the average deep 

edge of seagrass growth varies from 0.8 m near the Myakka River, to 1.4 m along the 

east and west shores of the Harbor, to 1.9 m in Cape Haze. The maximum depth of 

seagrass growth increases with proximity towards Boca Grande Pass and Gulf of 

Mexico Waters (CHNEP 2006). 

 The watershed for Gasparilla Sound-Charlotte Harbor and Cape Haze Aquatic 

Preserves begins for the Peace River at Lake Hancock in Polk County and for the 

Myakka River at Flatford Swamp in Sarasota County. Including the seven tributaries 

and rivers, the watershed area is approximately 8008 km2

 (1,978,800 acres) in size. 

The land to water ratio is 22:1. The 1990 and 2010 projected land uses in the 

watershed are shown in Table 7.4. The land uses vary greatly throughout the ten subbasins, but watershed-wide, the largest land uses are pasture (27%), rangeland (16%) 

and upland forest (12%). Urban land use and mining comprise 7% and 6% of the 

watershed, respectively. A large percent of the estuary shoreline is preserved and 

managed as the Charlotte Harbor Preserve State Park. Urban areas are centered 

adjacent to the estuary at Punta Gorda and Port Charlotte, along the Peace River at 

Arcadia and Bartow, and near Lake Hancock. The most critical changes in predicted 

future land uses are a >125% increase in mining and nearly a 300% increase in 

residential areas. There are over 181 domestic wastewater point source discharges, 

202 industrial wastewater discharges, 22 public water supplies and 26 industrial/mining 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

106

water uses permitted in the watershed, as well as high agricultural demand (CHNEP 

1999). 

2. Water Quality Status and Trends Results for Upper Charlotte Harbor 

 Water quality in Upper Charlotte Harbor was generally below average compared 

to other estuaries in the region and across the state of Florida. Upper Charlotte Harbor 

was tied with Upper Lemon Bay for the lowest median Secchi value and had the highest 

median total phosphorus and color of all estuary regions. The TP in Upper Charlotte 

Harbor had significantly increased over the study period and the median value for all 

years was higher than average compared to Florida’s estuaries, ranking in the 70th

percentile or above. Fecal coliform bacteria levels were also high in the area and 

frequently exceeded Florida Surface Waters Criteria at 200, 400 and 800 cfu/100mL. 

Salinity in Upper Charlotte Harbor significantly decreased over the study duration and 

was the lowest recorded median value across all estuary regions. Decreasing salinity 

levels may correspond to an increasing trend in color concentrations that was also 

detected in the region. Additional significant trends included an increase of DO at a rate 

of approximately 0.1 mg/L. Status and trends results for Upper Charlotte Harbor are 

shown in Table 7.5. 

 Site-specific water quality varied throughout the Upper Charlotte Harbor estuary 

region. Sites CHV005 and CHV013 ranked among the sites having the lowest salinity 

and highest nutrients and chlorophyll a. Both sites had higher than average status 

results for total phosphorus compared to typical Florida estuarine water quality. Fecal 

coliform was high at both sites, particularly in the rainy season, with frequent 

exceedances of state standards. Sites CHV005 and CHV013 are the most upstream 

sites in the Tidal Peace River. Site-specific water quality status results are shown in 

Appendix A. 

3. Water Quality Status and Trends Results for Lower Charlotte Harbor

 Lower Charlotte Harbor had fair to good water quality for all water quality 

parameters. Turbidity values in Lower Charlotte Harbor significantly decreased during 

the study period, and were tied with Matlacha Pass for the lowest median value 

observed across all estuary regions. The median Secchi depth value was above 

average in comparison to typical values for Florida estuaries. Salinity significantly 

decreased in the region, possibly corresponding to a significant decrease in pH and an 

increase in color concentrations. Additional significant trends include an increase in DO 

and a decrease in TKN. Status and trends results for Lower Charlotte Harbor are 

shown in Table 7.6 

 Site CHV011 exhibited above average water quality compared to other sites in 

the CHEVWQMN and across Florida estuaries. This open water site is located in the 

center of Lower Charlotte Harbor and had the deepest average depth of all the sites 

(3.8 m). Site CHV011 had the highest median Secchi value (2.3 m) for all sites in the 

CHEVWQMN and was the only site that ranked in the 100th percentile of all Florida 

estuaries. The site had the lowest median total nitrogen and turbidity across all sites in 

the CHEWVQMN, and fecal coliform bacteria was tied for the lowest. Site CHV011 also 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

107

had the lowest percent regulatory exceedances of DO less than 5.0 mg/L within the 

region. Site specific water quality status results are shown in Appendix A. 

4. Water Quality Status and Trends Results for Gasparilla Sound/Cape Haze 

 Water quality in Gasparilla Sound/Cape Haze had many parameters falling within 

the 40th to 60th percentiles of Florida’s estuaries and moderate rankings within the 

CHEVWMQN. Secchi depth was relatively high, with a median value of 1.5 m, which 

fell within the 70th percentile of Florida’s estuaries. Chlorophyll a concentrations were 

very low in the region, with few regulatory exceedances. The DO levels were generally 

low, with frequent regulatory exceedances of 4.0 and 5.0 mg/L. Cape Haze was the 

only estuary region in which DO appeared to be significantly decreasing. Other 

significant observed trends included a significant increase in color concentrations, as 

well as decreases in salinity, pH and turbidity values. Status and trends results for 

Gasparilla Sound/Cape Haze are shown in Table 7.7 

 Water quality was relatively consistent across the four sites located in Cape 

Haze, ranging from below to above average depending on the parameter of interest. 

Sites GSV001 and GSV004 had the most DO samples below state regulatory criteria of 

4.0 and 5.0 mg/L. Median values for GSV001 and GSV004 were also below the 4.0 

mg/L standard, at 4.0 and 3.6 mg/L, respectively. Additionally, GSV001 had the lowest 

chlorophyll a median value (2.16 μg/L) across all sites in the CHEVWQMN. Site 

GSV003 had the lowest color value of all sites in the CHEVWQMN, with a median value 

of 10 PCU and ranking in the 30th percentile of Florida’s estuaries. Site specific water 

quality status results are shown in Appendix A. 

5. Discussion 

CHEVWQMN results indicated that overall water quality in the Gasparilla Sound, 

Cape Haze and Charlotte Harbor Aquatic Preserves was average based upon the 

parameter and region of interest. Water clarity was average to higher than average in 

the Upper Charlotte region, with color concentrations being the primary parameter 

contributing most to light attenuation across the region, followed by turbidity. Nutrients, 

including nitrogen and phosphorus, were higher than average, particularly in the Upper 

Charlotte Harbor region. Below-average DO values, as well as frequent observations 

below state standards of 4.0 and 5.0 mg/L, are also cause for concern across these 

preserves. 

 Due to the complex nature of the Gasparilla Sound-Charlotte Harbor and Cape 

Haze Aquatic Preserves and their watershed, effective resource management goals 

should be multi-faceted, focusing on: a) identifying and reducing sources of high 

nutrients to minimize chlorophyll a contributions to attenuation of seagrass growth; b) 

restoring and maintaining natural surface and ground water hydrology, to sustain the 

complex interconnectedness of life stages of finfish and shellfish throughout the Harbor; 

c) identifying, quantifying, minimizing and remediating water quantity and quality 

impacts from current and future mining and agriculture activities; and d) developing a 

better understanding of the role and natural variability of color in the estuary.
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

108

Table 7.4: Land use types in the Charlotte Harbor, Gasparilla Sound and Cape Haze watershed

Projected

Land Use1,2,3,4 acres % acres % Change

Urban

 Residential 103,196 5% 470,864 24%

 Commercial/Industrial/Institutional 31,816 2% 65,003 3%

 Sub Total 135,012 7% 535,867 27% 297%

Mining 126,746 6% 286,484 14% 126%

Agriculture

 Row Crops/Groves/Nursery 201,960 10% 0 0%

 Pasture/Feedlot 539,534 27% 0 0%

 Sub Total 741,494 37% 939,044 47% 27%

Open Land, Wetlands, Water

 Forest/Range/Barren/Preserve 552,607 28% 182,110 9%

 Wetlands 359,606 18% 35,302 2%

 Open Water 63,341 3% 0 0%

 Sub Total 975,554 49% 217,411 11% -78%

TOTAL 1,978,806 100% 1,978,806 100%

1

Includes Gasparilla Sound/Charlotte Harbor and Cape Haze Aquatic Preserves.

2

 Includes Upper Charlotte Harbor, Lower Charlotte Harbor and Gasparilla Sound/Cape Haze Estuary Regio

3 Includes Upper Myakka R, Lower Myakka R, Peace R/Bartow, Peace R/Zolfo Springs, Peace R/Arcadia, 

 Peace R/Lower, Payne Cr, Charlie Cr, Horse Cr, Joshua Cr, Shell Cr and Charlotte Harbor Sub-Watershe

4

 From "Synthesis of Existing Information", Charlotte Harbor National Estuary Program 1999.

 Based on SWFWMD, SFWMD and Southwest Florida Regional Planning Council data.

1990 2010
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

109

Table 7.5: Status and Trends Summary for Upper Charlotte Harbor

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries1

Median compared 

to Typical FL 

Estuary 

Percentiles2

Status Relative to 

Typical FL 

Estuaries

Trend 

Results3

Secchi (m) 394 0.1 2.7 0.9 0.0 0.9 1 40 average

Temp (deg. C) 657 4.0 31.5 23.6 0.2 24.0 1 50 average

DO (mg/L) 650 0.6 9.9 5.2 0.1 5.2 5 20 lower than average ↑

pH 657 6.4 8.6 7.7 0.0 7.8 1 30 lower than average

Salinity (ppt) 649 0.0 37.1 17.3 0.4 17.9 1 30 lower than average ↓

TN (ppm) 505 0.032 4.602 1.040 0.022 0.975 8 70 higher than average

TP (ppm) 532 0.010 1.500 0.305 0.009 0.240 9 80 higher than average ↑

Chl a (ug/L) 482 0.01 88.50 9.48 0.50 6.16 8 50 average

Coliform (cfu/100mL) 587 1 800 48 4 24 8 70 higher than average

Turbidity (NTU) 556 0.5 24.0 3.2 0.1 2.7 6 40 average

Color (PCU) 557 4 400 70 3 50 9 70 higher than average ↑

1 Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

2 Median value compared to typcial Florida estuarine water quality percentile distributions (Hand in press 2004)

3

↓ Significantly decreasing at the .05 level 3

↑ Significantly increasing at the .05 level
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

110

Table 7.6: Status and Trends Summary for Lower Charlotte Harbor

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries1

Median compared 

to Typical FL 

Estuary 

Percentiles2

Status Relative to 

Typical FL 

Estuaries

Trend 

Results3

Secchi (m) 105 0.5 4.5 1.8 0.1 1.5 7 70 higher than average

Temp (deg. C) 252 13.0 31.5 23.9 0.3 24.5 3 50 average

DO (mg/L) 247 2.4 9.1 5.4 0.1 5.5 6 20 lower than average ↑

pH 249 7.4 8.6 8.3 0.0 8.2 3 80 higher than average ↓

Salinity (ppt) 248 8.5 39.1 28.2 0.4 29.0 4 70 higher than average ↓

TN (ppm) 207 0.055 2.300 0.792 0.028 0.755 3 50 average ↓4

TP (ppm) 215 0.005 0.420 0.114 0.005 0.100 7 50 average

Chl a (ug/L) 198 0.01 34.18 5.88 0.35 4.42 6 30 lower than average

Coliform (cfu/100mL) 234 1 372 13 2 3 3 40 average

Turbidity (NTU) 226 0.1 21.0 2.5 0.2 2.1 1 30 lower than average ↓

Color (PCU) 226 1 140 30 2 24 5 50 average ↑

1 Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

2 Median value compared to typcial Florida estuarine water quality percentile distributions (Hand in press 2004)

3

↓ Significantly decreasing at the .05 level 3

↑ Significantly increasing at the .05 level

4 Trend results of total Kjeldahl nitrogen
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

111

Table 7.7: Status and Trends Summary for Gasparilla Sound/Cape Haze

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries1

Median compared 

to Typical FL 

Estuary 

Percentiles2

Status Relative to 

Typical FL 

Estuaries

Trend 

Results3

Secchi (m) 86 0.0 3.2 1.5 0.1 1.5 7 70 higher than average

Temp (deg. C) 192 7.5 31.5 24.2 0.3 25.0 8 60 average

DO (mg/L) 188 1.4 7.3 4.6 0.1 4.6 2 10 lower than average ↓

pH 194 7.2 8.6 8.3 0.0 8.2 3 80 higher than average ↓

Salinity (ppt) 192 10.0 40.7 31.5 0.4 33.2 8 100 higher than average ↓

TN (ppm) 141 0.075 2.526 0.906 0.042 0.806 6 60 average

TP (ppm) 150 0.005 0.350 0.093 0.005 0.080 6 40 average

Chl a (ug/L) 145 0.50 18.20 4.49 0.31 3.58 3 20 lower than average

Coliform (cfu/100mL) 169 1 280 20 3 6 5 50 average

Turbidity (NTU) 162 0.6 30.0 3.3 0.2 2.7 6 40 average ↓

Color (PCU) 162 3 120 24 1 20 3 50 average ↑

1 Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

2 Median value compared to typcial Florida estuarine water quality percentile distributions (Hand in press 2004)

3

↓ Significantly decreasing at the .05 level 3

↑ Significantly increasing at the .05 level
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

112

D. Pine Island Sound and Matlacha Pass Aquatic Preserves 

Including Pine Island Sound and Matlacha Pass Estuary Regions 

1. Background 

 Pine Island Sound and Matlacha Pass surround Pine Island from north to south 

and are bordered by barriers islands and Pine Island to the west. Pine Island Sound 

Aquatic Preserve extends from Boca Grande Pass south to Sanibel, between Pine 

Island and four barrier islands. There is one primary tributary (Caloosahatchee River) 

and four Gulf passes (Boca Grande, Captiva, Red Fish and Blind). The aquatic 

preserve boundary follows the mean high waterline of the Sound. Pine Island Sound is 

approximately 29 km (18 mi) long and 8 km (5 mi) wide, with an area of approximately 

219 km2

 (54,176 acres). It is the second largest and second deepest of the estuaries in 

the region. The aquatic preserves are located in Lee County and the City of Sanibel is 

the only incorporated area on the Sound. 

 Matlacha Pass Aquatic Preserve is located between Pine Island and Cape Coral, 

extending north-south along the length of the island. The primary tributary is the 

Caloosahatchee River, as well as overland flow from preserve lands to the east. The 

aquatic preserve boundary follows the mean high waterline of the Pass, with the 

exclusion of a small area to the south. Matlacha Pass is approximately 21 km (13 mi) 

long and 5 km (3 mi) wide, with an area of approximately 50 km2

 (12,511 acres). It is the 

most sinuous of the estuaries in the region. The aquatic preserve is located in Lee 

County and the primary adjacent urban area is Cape Coral (CHNEP 1999). 

 Within both estuaries, the largest submerged habitat is seagrass, comprising 

approximately 142 km2

 (35,170 acres) of the estuarine area. The average deep edge of 

seagrass growth is approximately 1.9 m in Pine Island Sound and 1.5 m in Matlacha 

pass (CHNEP 1999).

 The Pine Island Sound and Matlacha Pass watershed includes the coastal areas 

of northern Lee and southern Charlotte Counties, Pine Island and the lower 

Caloosahatchee River drainage area. The watershed is approximately 355 km2

 (87,850 

acres) in size. The ratio of watershed land area to open water estuary area is slightly 

over 1:1. The 1990 and 2010 projected land uses in the watershed are shown in Table 

7.8. Based on the 1990 data, the largest land use in the watershed is rangeland (33%) 

and upland forest (16%). Urban uses make up a relatively small percent (14%) of the 

overall watershed, but it is concentrated in the City of Cape Coral to the east of 

Matlacha Pass. A large percent of the estuary shoreline is managed for preservation 

under the Charlotte Harbor Preserves State Park, "Ding" Darling National Wildlife 

Refuge and the nonprofit Calusa Land Trust. The most significant projected change in 

future land use is the very large increase (almost 350%) in urban uses. The urban 

areas are concentrated on the east side of Matlacha Pass in Cape Coral, but are 

increasing rapidly on Sanibel and Pine Island. There are 57 domestic wastewater 

discharges, seven industrial wastewater discharges and three public water supplies 

permitted in the watershed, along with significant demand for landscape and golf course 

irrigation (CHNEP 2006). 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

113

2. Water Quality Status and Trends Results for Pine Island Sound 

 Results from the CHEVWQMN indicated that water quality in Pine Island Sound 

ranged from below average to above average compared to the typical water quality of 

Florida’s estuaries and ranked very well compared to other estuary regions in the 

Charlotte Harbor area. The median Secchi depth value of 1.3 m was average 

compared to Florida’s estuaries (Hand 2004). Pine Island Sound had the lowest 

median nutrient levels across the nine estuary regions. The TKN significantly 

decreased over the study duration. Additional significant trends included an increase in 

pH and decreases in salinity, fecal coliform bacteria and turbidity values. For water 

quality status and trends results in Pine Island Sound, see Table 7.9. 

 Water quality was relatively uniform across most sites in Pine Island Sound. Site 

PIJIM1 exhibited the lowest water quality across all sites. The site is located near Big 

Jim Creek on the northwestern side of Pine Island. It had the shallowest average depth 

of all sites, with high fecal coliform bacteria, low water clarity and DO values. The site 

had the lowest Secchi depth and DO median values of all sites in the CHEVWQMN, 

ranking in or below the lower 20th percentile of Florida’s estuaries. The site is located 

near Big Jim Creek on the northwestern side of Pine Island and had the shallowest 

average depth of all sites. Sites PIV004 and PIV006 had the best relative water quality 

in comparison to sites within the Pine Island Sound region and across all sites in the 

region. These are both open water sites on the eastern side of Captiva and Sanibel 

Islands. Both sites had the highest DO levels across all sites, and Secchi depth at 

PIV004 was the second highest of all sites in the CHEVWQMN. Site specific water 

quality status results are shown in Appendix A. 

3. Water Quality Status and Trends Results for Matlacha Pass 

Water quality in Matlacha Pass ranked moderately compared to other estuary 

regions in the Charlotte Harbor estuarine complex. Secchi depth was high in the region 

with a median value of 1.6 m, ranking highest among CHEVWQMN regions and in the 

80th percentile of Florida estuaries. Salinity varied seasonally in the region, was 

generally lower than other estuary regions and was average compared to salinity values 

for Florida’s estuaries. Matlacha had the second lowest chlorophyll a median value 

across all estuary regions and had no annual means exceeding 11 μg/L per Florida’s 

Impaired Waters Rule. Matlacha Pass was the only estuary region in the study area 

which had no site demonstrating exceedances of Florida’s Surface Water Standards for 

fecal coliform bacteria at 200, 400 and 800 cfu/100mL. Color concentrations were 

average and significantly increased over the study duration. Other significant trends 

include an increase in DO and pH, and decreases in salinity and temperature. For 

water quality status and trends results in Matlacha Pass, see Table 7.10. 

 Water quality results were fairly uniform across the three sites located in 

Matlacha Pass. All sites were located in open water with a minimum average sample 

depth of 2 m. Site MPV003 had the second lowest median chlorophyll a value across 

all sites. Site MPV003 tied with PIV004 for the second highest Secchi depth across all 

sites in the CHEVWQMN. Site-specific water quality status results are shown in 

Appendix A. 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

114

4. Discussion 

 Water quality in Pine Island Sound and Matlacha Pass was average to above 

average compared to other regions within Charlotte Harbor and estuaries across the 

state. Color concentrations were higher than average in Matlacha Pass and was the 

primary factor contributing to decreases in water clarity. Secchi depth was average in 

Pine Island Sound with turbidity as the primary parameter causing light attenuation. 

Below average DO and nitrogen within Matlacha Pass are key water quality issues 

affecting this region. 

 To maintain the relatively good water quality conditions throughout Pine Island 

Sound and Matlacha Pass, resource management goals should focus on reducing 

nutrient runoff from the increasing urban and nursery areas on the islands. Due to the 

close proximity of both surface and ground water to upland activities on the islands, 

additional design considerations should be incorporated in storm water management 

measures. Additionally, natural and anthropogenic sources of turbidity in Pine Island 

Sound should be identified and quantified, and remediated as needed. 

Table 7.8: Land uses in the Pine Island Sound and Matlacha Pass watershed

2010 Projected Projected

Land Use1, 2, 3, 4 acres % acres % Change

Urban

 Residential 7,228 8% 45,477 52%

 Commercial/Industrial/Institutional 5,196 6% 10,355 12%

 Sub Total 12,424 14% 55,812 64% 349%

Mining 167 0% 0 0% -100%

Agriculture

 Row Crops/Groves/Nursery 704 1%

 Pasture/Feedlot 2,009 2%

 Sub Total 2,713 3% 0 0% -100%

Open Land, Wetlands, Water

 Forest/Range/Barren/Preserve 44,868 51% 32,036 36%

 Wetlands 23,174 26%

 Open Water 4,502 5%

 Sub Total 72,544 83% 32,036 36% -56%

TOTAL 87,848 100% 87,848 100%

1

Includes Pine Island Sound and Matlacha Pass Aquatic Preserves.

2

 Includes Pine Island Sound and Matlacha Pass Estuary Regions.

3 Includes Pine Island Sound/Matlacha Pass Watershed.

4

 From "Synthesis of Existing Information", Charlotte Harbor National Estuary Program 1999.

 Based on SWFWMD, SFWMD and Southwest Florida Regional Planning Council data.

1990
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

115

Table 7.9: Status and Trends Summary for Pine Island Sound

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries1

Median compared 

to Typical FL 

Estuary 

Percentiles2

Status Relative to 

Typical FL 

Estuaries

Trend 

Results3

Secchi (m) 167 0.1 3.9 1.4 0.0 1.3 4 70 higher than average

Temp (deg. C) 400 10.5 31.0 23.6 0.2 24.5 3 60 average

DO (mg/L) 392 0.6 9.0 5.7 0.1 5.9 8 30 lower than average

pH 388 7.0 8.8 8.4 0.0 8.4 9 100 higher than average ↑

Salinity (ppt) 399 4.5 42.0 32.2 0.2 32.9 7 90 higher than average ↓

TN (ppm) 309 0.055 4.302 0.808 0.027 0.752 1 50 average ↓4

TP (ppm) 330 0.005 0.900 0.073 0.004 0.060 1 30 lower than average

Chl a (ug/L) 298 0.01 39.70 6.52 0.34 4.98 7 40 average

Coliform (cfu/100mL) 383 1 352 13 2 2 1 40 average ↓

Turbidity (NTU) 368 0.3 28.0 3.7 0.2 2.6 4 40 average ↓

Color (PCU) 369 1 200 25 1 18 2 40 average

1 Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

2 Median value compared to typcial Florida estuarine water quality percentile distributions (Hand in press 2004)

3

↓ Significantly decreasing at the .05 level 3

↑ Significantly increasing at the .05 level

4 Trend results of total Kjeldahl nitrogen
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

116

Table 7.10: Status and Trends Summary for Matlacha Pass

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries1

Median compared 

to Typical FL 

Estuary 

Percentiles2

Status Relative to 

Typical FL 

Estuaries

Trend 

Results3

Secchi (m) 202 0.4 3.8 1.6 0.0 1.6 9 80 higher than average

Temp (deg. C) 261 13.5 31.0 24.0 0.3 24.5 3 50 average ↓

DO (mg/L) 252 2.0 9.0 5.5 0.1 5.5 6 30 lower than average ↑

pH 250 7.4 8.6 8.2 0.0 8.2 3 80 higher than average ↑

Salinity (ppt) 258 2.9 39.8 21.7 0.5 22.1 2 40 average ↓

TN (ppm) 194 0.032 3.840 0.905 0.032 0.851 7 60 average

TP (ppm) 212 0.010 0.290 0.084 0.003 0.076 5 40 average

Chl a (ug/L) 187 0.25 72.50 5.42 0.52 3.50 2 20 lower than average

Coliform (cfu/100mL) 234 1 106 9 1 4 4 40 average

Turbidity (NTU) 221 0.1 10.5 2.5 0.1 2.1 1 30 lower than average

Color (PCU) 221 1 160 37 2 30 6 60 average ↑

1 Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

2 Median value compared to typcial Florida estuarine water quality percentile distributions (Hand in press 2004)

3

↓ Significantly decreasing at the .05 level 3

↑ Significantly increasing at the .05 level
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

117

E. San Carlos Bay 

Including San Carlos Bay Estuary Region 

1. Background 

 San Carlos Bay, while not designated as an aquatic preserve itself, connects 

three adjacent aquatic preserves: Matlacha Pass, Pine Island Sound and Estero Bay 

Aquatic Preserves. It is located at the mouth of the Caloosahatchee River, its primary 

tributary. San Carlos Bay is approximately 6 km (4 mi) long and 5 km (3 mi) wide. It is 

located in Lee County and adjacent urban areas include Cape Coral, Fort Myers and 

Fort Myers Beach. Within the estuary, seagrasses are an important submerged habitat 

compromising approximately 20 km2

 (5,000 acres), growing to approximately 2.0 m 

deep, though the conditions vary annually, seasonally and with changes in hydrologic 

flows from the Caloosahatchee River (CHNEP2006). 

 The San Carlos Bay watershed includes the lower drainage area of the 

Caloosahatchee River and is approximately 937 km2

 (231,638 acres) in size. The 1990 

and 2010 projected land uses in the watershed are shown in Table 7.11. Based on the 

1990 data, the largest land use in the watershed is urban (33%), followed by pasture 

(21%). The most significant projected changes in future land uses are a large increase 

(80%) in urban area and a large decrease (74%) in wetland areas. A small portion of 

the estuary shoreline is in preserve use managed by the Charlotte Harbor Preserves 

State Park, "Ding" Darling National Wildlife Refuge and the nonprofit Calusa Land Trust. 

There are 76 domestic wastewater discharges, seven industrial wastewater discharges, 

five public water uses and an undetermined number of industrial uses permitted in the 

watershed, along with high demand for landscape and golf course irrigation (CHNEP 

1999). 

2. Water Quality Status and Trends Results 

 San Carlos Bay had above average water quality and ranked as having the 

highest water quality of all estuary regions in the CHEVWQMN study area. San Carlos 

and Estero Bays were the only estuaries exhibiting a significant increase in Secchi 

depth over the eight-year study duration, with the median value for all years ranking in 

the top 70th percentile of Florida’s estuaries. Total nitrogen was average compared to 

Florida’s estuaries, with total nitrogen and TKN median values ranking second across 

all estuaries within the Charlotte Harbor region. The median chlorophyll a value was 

lower than the average value for Florida’s estuaries and was the lowest concentration of 

all estuary regions in the CHEVWQMN. No site within San Carlos Bay demonstrated 

chlorophyll a annual means exceeding the state criteria of 11 μg/L. San Carlos Bay tied 

for the lowest median fecal coliform bacteria concentrations across all estuary regions in 

the Charlotte Harbor study area. The DO and color values significantly increased over 

the study duration, while salinity, temperature and turbidity levels significantly 

decreased. For water quality status and trends results in San Carlos Bay see, Table 

7.12. 

 Site-specific water quality results were generally uniform in San Carlos Bay. 

Sites SCV001 and SCV002 had the highest median DO values within the region, with 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

118

only four samples at each site under 5.0 mg/L per Florida’s Surface Water Standards. 

San Carlos had the second deepest average depth of 3.7 m, with site depths ranging 

from 2.5 to 4.5 m. All sites in San Carlos Bay are located offshore, generally outside or 

bordering Aquatic Preserves boundaries. Site specific water quality status results are 

shown in Appendix A. 

3. Discussion 

CHEVWQMN results in San Carlos Bay indicate generally above average water 

quality conditions. Water quality conditions of concern include salinity variability, lower 

than average DO results and increases in color concentrations throughout the study 

duration. In San Carlos Bay, color was the primary parameter contributing most to 

changes in water clarity. In addition to these findings, previous studies have shown that 

artificially induced salinity variability and nutrient enrichment are important water quality 

issues in the San Carlos estuary (Doering and Chamberlain 1999; Doering et al. 2005, 

Greenawalt-Boswell et al. 2006). San Carlos Bay is located at the mouth of the 

Caloosahatchee River, which, during high discharge, is a major contributor of 

freshwater flow and nutrients to the entire Charlotte Harbor estuarine complex (Doering 

et al. 2005). 

 Water quality conditions in the San Carlos Bay estuary are strongly influenced by 

variability in freshwater flow via the Caloosahatchee River and subsequently changes 

within the Caloosahatchee watershed. A better understanding of the effects of changes 

in hydrologic regimes and watershed land uses is essential for sustaining and restoring 

the productive submerged habitats of San Carlos Bay, including seagrass meadows, 

shellfish communities and fisheries populations. 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

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119

Table 7.11: Land uses in the San Carlos Bay watershed

Projected

Land Use1, 2, 3, 4 total % total % Change

Urban

 Residential 67,351 29% 118,689 51%

 Comm/Indust/Institutional 8,432 4% 17,397 8%

 Sub Total 75,783 33% 136,086 59% 80%

Mining 1,629 1% 0 0% -100%

Agriculture

 Row Crops/Groves/Nursery 3,170 1% 0 0%

 Pasture/Feedlot 49,074 21% 0 0%

 Sub Total 52,244 23% 68,921 30% 32%

Open Land, Wetlands, Water

 Forest/Barren/Range/Preserve 61,628 27% 26,631 11%

 Wetlands 38,615 17% 0 0%

 Open Water 1,739 1% 0 0%

 Sub Total 101,982 44% 26,631 11% -74%

TOTAL 231,638 100% 231,638 100%

1

Includes San Carlos Bay, which is not an Aquatic Preserve.

2

 Includes San Carlos Bay Estuary Region.

3 Includes Lower Caloosahatchee, Telegraph Swamp and Orange River Watersheds.

4

 From "Synthesis of Existing Information", Charlotte Harbor National Estuary Program 1999.

 Based on SWFWMD, SFWMD and Southwest Florida Regional Planning Council data.

1999 2010
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

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120

Table 7.12: Status and Trends Summary for San Carlos Bay

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries1

Median compared 

to Typical FL 

Estuary 

Percentiles2

Status Relative to 

Typical FL 

Estuaries

Trend 

Results3

Secchi (m) 327 0.5 3.9 1.5 0.0 1.4 6 70 higher than average ↑

Temp (deg. C) 340 10.0 31.0 24.1 0.3 24.8 7 50 average ↓

DO (mg/L) 334 2.8 8.7 5.9 0.1 5.9 8 30 lower than average ↑

pH 339 7.4 8.6 8.3 0.0 8.2 3 80 higher than average

Salinity (ppt) 339 8.8 41.4 29.1 0.4 30.6 6 80 higher than average ↓

TN (ppm) 249 0.055 2.930 0.755 0.025 0.753 2 50 average

TP (ppm) 263 0.005 0.270 0.069 0.002 0.060 1 30 lower than average

Chl a (ug/L) 245 0.01 28.35 4.41 0.25 3.43 1 20 lower than average

Coliform (cfu/100mL) 310 1 364 12 2 2 1 40 average

Turbidity (NTU) 294 0.5 120.0 4.2 0.4 3.2 8 50 average ↓

Color (PCU) 294 1 160 27 1 20 3 50 average ↑

1 Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

2 Median value compared to typcial Florida estuarine water quality percentile distributions (Hand in press 2004)

3

↓ Significantly decreasing at the .05 level 3

↑ Significantly increasing at the .05 level
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

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F. Estero Bay Aquatic Preserve 

Including Estero Bay Estuary Region 

1. Background 

 Estero Bay Aquatic Preserve includes Estero Bay from Fort Myers Beach south 

to Bonita Springs. There are six tributaries (Hendry, Mullock, and Spring Creeks, 

Caloosahatchee, Estero and Imperial Rivers) and four Gulf Passes (Matanzas, Big 

Carlos, New and Big Hickory). The aquatic preserve boundary follows the mean high 

waterline of the Bay and the tributaries up-stream to tidal influence. Estero Bay is 

approximately 14 km (9 mi) long and 3 km (2 mi) wide, with an area of approximately 40 

km2

 (9,834 acres). It is the second smallest and shallowest of the estuaries in the 

region. The aquatic preserve is located in Lee County and is adjacent to the urban 

areas of Fort Myers, Fort Myers Beach and Bonita Springs. Seagrass is a critical 

submerged habitat in Estero Bay, comprising over 14 km2

 (3,400 acres), growing to an 

average depth of 1.0 m. Seagrass acreage in Estero Bay appears to have declined 

over the past decade (CHNEP 2006). 

 The Estero Bay watershed extends to the headwaters of the creeks and the 

lower drainage area of the Caloosahatchee River and is approximately 754 km2

(186,200 acres) in size. The 1990 and 2010 projected land uses in the Estero Bay 

watershed are shown in Table 7.13. The ratio of watershed land area to open water 

estuary area is approximately 19:1. Based on the 1990 data, the largest land use in the 

watershed is forested and non-forested wetlands (37%), followed by forest and 

rangeland (24%) and pasture (18%). The most significant projected change in future 

land use is a large increase (253%) in urban area and a large decrease in wetlands and 

preserve lands. There is also a projected increase in the of acquisition public lands for 

preservation. The shoreline of the estuary is predominately urban use. There are 113 

domestic wastewater discharges, fourteen industrial wastewater discharges, six public 

water uses and an undetermined number of industrial uses permitted in the watershed. 

In addition, there is a large demand for irrigation for golf courses, landscaping and some 

agriculture (CHNEP 1999). 

2. Water Quality Status and Trends Results for Estero Bay 

 Water quality in Estero Bay ranked moderately compared to other estuary 

regions in the CHEVWQMN study region, with median values ranging from below to 

above typical Florida estuarine water quality values (Hand 2004). Estero Bay had the 

highest turbidity levels in the region, with a median value of 4.2 NTU, ranking in the 60th

percentile of Florida’s estuaries. The DO value was below average compared to typical 

Florida estuaries and was frequently observed below the Florida Surface Waters 

Standards of 4.0 and 5.0 mg/L. The pH, temperature and salinity levels significantly 

decreased over the study period, with significant increases in Secchi depth and color 

concentrations over the eight-year period. For water quality status and trends results in 

Estero Bay, see Table 7.14. 

 Sites EBV006, EBV004 and EBV005 had the highest median turbidity values of 

all sites in the CHEVWQMN. Turbidity at these sites ranked in the top 70th and 80th
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

122

percentiles of Florida’s estuaries, resulting in an overall below average status rating. 

Site EBERS2, located at the mouth of the Estero River, had DO results that were below 

Florida’s estuarine average and had the lowest median DO value (4.0 mg/L) in the 

estuary. Salinity and turbidity levels were also lowest at EBERS2. Site specific water 

quality status results are shown in Appendix A. 

3. Discussion 

Water quality conditions in Estero Bay were generally average. The 

CHEVWQMN results indicate that issues of concern in the region include: turbidity, 

fecal coliform bacteria and below-average DO concentrations. Estero Bay is a shallow 

wind-driven estuary in which turbid conditions are the primary result of resuspension of 

sediments within and from the Gulf of Mexico (Tapping et al. 2005). In addition, turbidity 

was the primary factor leading to light attenuation in Estero Bay. Regulatory 

exceedances of fecal coliform bacteria were spatially and temporally isolated indicating 

that causes of increased bacteria are site- and event-specific. Lower than average DO 

concentrations near the Estero River indicate that inflow from the river may be a source 

of degraded water quality within the estuary. 

 The most effective resource management goals for Estero Bay should address 

high turbidity levels, differentiating between natural and anthropogenic sources. 

Reductions in turbidity, along with restoration of natural salinity regimes would 

contribute to reestablishing seagrasses within the Bay. Continued acquisition and 

management of preserve lands in the watershed will help offset the rapidly increasing 

urbanization. 
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

123

Table 7.13: Land uses in the Estero Bay watershed

Projected

Land Use1, 2, 3, 4 acres % acres % Change

Urban

 Residential 19,417 10% 69,458 37%

 Commercial/Industrial/Institutional 6,359 3% 21,454 12%

 Sub Total 25,776 14% 90,912 49% 253%

Mining 1,889 1% 0 0% -100%

Agriculture

 Row Crops/Groves/Nursery 11,500 6%

 Pasture/Feedlot 31,795 18%

 Sub Total 43,295 24% 52,721 28% 22%

Open Land, Wetlands, Water

 Forest/Range/Barren/Preserve 43,883 24% 42,528 23%

 Wetlands 69,259 37%

 Open Water 2,059 1%

 Sub Total 115,201 62% 42,528 23% -63%

TOTAL 186,161 100% 186,161 100%

1

Includes Estero Bay Aquatic Preserve.

2

 Includes Estero Bay Estuary Region.

3 Includes Estero Bay Watershed.

4

 From "Synthesis of Existing Information", Charlotte Harbor National Estuary Program 1999.

 Based on SWFWMD, SFWMD and Southwest Florida Regional Planning Council data.

1990 2010 Projected
Summaries of Status and Trends Results for each Estuary CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

124

Table 7.14: Status and Trends Summary for Estero Bay

N Min Max Mean SE Median

Median Rank 

within the 

Charlotte Harbor 

Esturaries1

Median compared 

to Typical FL 

Estuary 

Percentiles2

Status Relative to 

Typical FL 

Estuaries

Trend 

Results3

Secchi (m) 177 0.3 2.9 1.2 0.0 1.1 3 50 average ↑

Temp (deg. C) 361 14.0 31.0 23.6 0.2 25.0 8 50 average ↓

DO (mg/L) 356 1.2 10.0 4.7 0.1 4.8 3 10 lower than average

pH 357 7.2 8.8 8.1 0.0 8.2 3 80 higher than average ↓

Salinity (ppt) 357 0.2 39.8 27.5 0.5 30.4 5 70 higher than average ↓

TN (ppm) 276 0.053 4.046 0.790 0.027 0.763 4 50 average

TP (ppm) 297 0.005 0.500 0.070 0.003 0.060 1 30 lower than average

Chl a (ug/L) 263 0.01 114.00 5.75 0.50 4.39 5 30 lower than average

Coliform (cfu/100mL) 331 1 800 44 5 10 7 60 average

Turbidity (NTU) 319 0.1 52.0 5.6 0.3 4.2 9 60 average

Color (PCU) 319 1 140 31 1 30 6 60 average ↑

1 Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

2 Median value compared to typcial Florida estuarine water quality percentile distributions (Hand in press 2004)

3

↓ Significantly decreasing at the .05 level 3

↑ Significantly increasing at the .05 level
Conclusions CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

125

VIII. Conclusions 

This report presents water quality status and trends results from the 

CHEVWQMN from 1998 through 2005 across the six Charlotte Harbor and Estero Bay 

Aquatic Preserves. Seventeen water quality parameters were measured across 48 

sampling sites grouped into nine estuary regions characterized by relatively 

homogenous hydrologic conditions. These water quality parameters reflect and affect 

the habitat health of the estuaries, including factors limiting light availability for seagrass 

growth and parameters potentially limiting the health and sustainability of fish and 

shellfish populations. Such factors include DO, turbidity and fecal coliform bacteria.

To characterize water quality as it relates to estuarine health, CHEVWQMN 

results were compared within the region and to other estuaries across the state of 

Florida. Median values ranking in the 31st to 60th percentiles of typical water quality 

values for Florida estuaries resulted in average water quality status. Additional 

comparisons were made to numerical criteria to aid in interpretation of water quality 

results. A seasonal, nonparametric trend test was used to detect trends in water quality 

from 1998 through 2005 for each estuary region. When interpreting results, 

consideration is given to the shallow near shore sampling site locations and sunrise 

sampling time, especially as it affects Secchi depth observations and may represent the 

lowest natural DO conditions. 

 Across the region, CHEVWMQN results indicated generally average conditions 

compared to Florida’s estuaries although results varied by parameter seasonally, 

spatially and over time. The DO concentrations were typically below average compared 

to typical Florida estuaries values with frequent exceedances below Florida Surface 

Water Criteria of 4.0 and 5.0 mg/L. Significant decreasing trends in salinity, turbidity, 

total Kjeldahl nitrogen and increases in color concentrations were observed for many 

estuaries from 1998 through 2005. Significant relationships between light-limiting 

factors and clarity were observed. However, the percent contribution of each parameter 

varied across the region and between the rainy and dry seasons. Strong relationships 

between salinity and many other parameters including color, nutrients and bacteria were 

also observed and quantified. 

Across the nine estuary regions analyzed in this report, water quality in Upper 

Lemon Bay and Upper Charlotte Harbor was below average compared to other estuary 

regions within the Charlotte Harbor area and across the state of Florida. Lower water 

clarity and DO, as well as higher color, nutrients and bacteria values were observed in 

these regions. A significant increase in TP was also observed in Upper Charlotte 

Harbor from 1998 through 2005. In Estero Bay, elevated color, turbidity and bacteria 

conditions were observed. 

 The CHEVWQMN successfully meets its intended goal of providing consistent, 

technically sound baseline water quality information throughout the six Charlotte Harbor 

and Estero Bay Aquatic Preserves, which facilitates data analysis. A rigorous quality 

assurance plan and extensive monitoring design allows for the accurate 

characterization of spatial and temporal water quality conditions across the region. The 

cost effective monitoring design includes synoptic sampling, representative fixed 

stations, a wide variety of field and lab parameters and a consistent, ongoing sampling 

duration. 
Conclusions CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

126

 The CHEVWQMN results are used to set resource management goals for the 

Charlotte Harbor Aquatic Preserves. Results from the CHEVWQMN also further 

resource managers’ understanding of water quality conditions as a means to identify 

priority pollutants, potential impacts from proposed permitting activities and locating 

impaired waters within the Charlotte Harbor estuaries. The CHEVWQMN data is also 

used by partnering organizations including the CHNEP, CHEC, Sanibel Captiva 

Conservation Foundation and Mote Marine Laboratory for research and to guide 

resource management activities. 

 In the future, CHEVWQMN water quality data will be used to evaluate future 

water quality trends, as well as to compare with monthly CCHMN monthly sampling and 

continuous monitoring datasondes managed by the Aquatic Preserves. Additionally, the 

water quality results will be compared to seagrass health, tributary in-flows and 

watershed influences throughout the region as a means to assess habitat responses to 

management practices and land use changes. Additional needs for the CHEVWQMN 

include: 1) increasing the number of sites to include deeper locations and fill spatial 

gaps, such as the west wall of Charlotte Harbor; 2) ensuring consistent laboratory 

support; 3) establishing numerical water quality criteria for the Charlotte Harbor 

estuaries; 4) developing estuary trophic state indices; and 5) continuing the program in 

order to promote continuity of data.

 The CHEVWQMN is made possible through the support of partnering agencies, 

staff and the invaluable contribution from citizen water monitors over the past ten years. 

The Charlotte Harbor and Estero Bay Aquatic Preserves would like to thank the many 

partnering agencies and volunteers as the CHEVWQMN celebrates its ten year 

anniversary in the fall of 2006.
References CHEVWQMN Report 2007

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

127

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Jaworksi, N.A. 1981. Sources of nutrients and the scale of eutrophication problems in 

estuaries, in Neilson, B.J., and Cronin, L.E., eds., Estuaries and nutrients: New 

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Mallin, M. A. and C.A. Corbett. 2006. How Hurricane Attributes Determine the Extent of 

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McPherson, B.F and R.L. Miller, 1990. Nutrient distribution and variability in the 

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. 

 
Appendix Table of Contents CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

I 

Appendix Table of Contents 

 Page 

Appendix A: Summary Statistics for Each Estuary and Site 

Table A.1: Seasonal summary statistics for all sites______________________ IV 

Table A.2: Annual summary statistics for all sites________________________ V 

Table A.3: Summary statistics for all sites in Upper Lemon Bay ____________ VI 

Table A.4: Summary statistics for all sites in Lower Lemon Bay ___________ VII 

Table A.5: Summary statistics for all sites in Upper Charlotte Harbor _______ VIII 

Table A.6: Summary statistics for all sites in Lower Charlotte Harbor ________ IX 

Table A.7: Summary statistics for all sites in Gasparilla/Cape Haze _________ X 

Table A.8: Summary statistics for all sites in Pine Island Sound ____________ XI 

Table A.9: Summary statistics for all sites in Matlacha Pass ______________ XII 

Table A.10: Summary statistics for all sites in San Carlos Bay ____________ XIII 

Table A.11: Summary statistics for all sites in Estero Bay ________________XIV 

Table A.12: Secchi depth (m) summary and status results for each site _____ XV 

Table A.13: Temperature (°C) summary and status results for each site_____XVI 

Table A.14: Dissolved oxygen (mg/L) summary and status results for each 

 Site ____________________________________________________ XVII 

Table A.15: pH summary and status results for each site _______________XVIII 

Table A.16: Salinity (ppt) summary and status results for each site ________XIX 

Table A.17: Total nitrogen (ppm) summary and status results for each site___ XX 

Table A.18: Total phosphorus (ppm) summary and status results for each 

 site _____________________________________________________XXI 

Table A.19: Chlorophyll a (μg/L) summary and status results for each site __ XXII 

Table A.20: Fecal coliform bacteria (cfu/100mL) summary and status results for 

each site _____________________________________________________XXIII 

Table A.21: Turbidity (NTU) summary and status results for each site ____ XXIV 

Table A.22: Color (PCU) summary and status results for each site ________ XXV 

Appendix B: Water Quality Comparisons 

Table B.1: Non parametric ANOVA (Kruskal-Wallis) results between aquatic preserves 

for the entire study duration ________________________________ XXVII 

Table B.2: Non parametric t-test (Mann-Whitney) results between the rainy and dry 

season ___________________________________________XXVIII-XXIX 

Table B.3: Aquatic Preserve non parametric t-test (Mann-Whitney) post hoc 

comparisons______________________________________ XXX-XXXVIII 

Appendix C: Comparison of Results to Numerical Water Quality Criteria 

Table C.1: Site exceedances of dissolved oxygen under 4 mg/L per site per Florida 

Surface Water Regulations __________________________________ XL 

Table C.2: Site exceedances of dissolved oxygen under 5 mg/L per site per Florida 

Surface Water Regulations __________________________________ XLI 

Table C.3: Exceedances of 11 ug/L chlorophyll a per Florida Impaired Waters Rule for 

each estuary region _______________________________________ XLII 

Table C.4: Site exceedances of chlorophyll a over 11 μg/L per site per Florida Surface 

Water Regulations ________________________________________ XLIII 
Appendix Table of Contents CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

II 

Table C.5: Site specific exceedances of fecal coliform bacteria per Florida Surface 

Water Regulations ________________________________________XLIV 

Appendix D: Water Quality Relationships 

Table D.1: Spearman's rho correlation for selected variables for the entire study region 

and duration _____________________________________________XLVI 

Table D.2: Spearman's rho correlation for selected variables in the rainy season for the 

entire study region _______________________________________ XLVII 

Table D.3: Spearman's rho correlation for selected variables in Upper Lemon 

 Bay ___________________________________________________XLVIII 

Table D.4: Spearman's rho correlation for selected variables in Lower Lemon 

 Bay ____________________________________________________XLIX 

Table D.5: Spearman's rho correlation for selected variables in Upper 

 Charlotte Harbor_____________________________________________L 

Table D.6: Spearman's rho correlation for selected variables in Lower 

 Charlotte Harbor____________________________________________ LI 

Table D.7: Spearman's rho correlation for selected variables in 

 Gasparilla/Cape Haze _______________________________________LII 

Table D.8: Spearman's rho correlation for selected variables in Pine Island 

 Sound___________________________________________________ LIII 

Table D.9: Spearman's rho correlation for selected variables in Matlacha 

 Pass ____________________________________________________ LIV 

Table D.10: Spearman's rho correlation for selected variables in San Carlos 

 Bay _____________________________________________________ LV 

Table D.11: Spearman's rho correlation for selected variables in Estero Bay _ LVI 

Appendix E: Rainfall Relationships 

Table D.1: Spearman's rho correlation for selected variables for the entire study 

region and duration _______________________________________ LVIII 
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

III 

Appendix A: Summary Statistics for Each Estuary and 

Site 

 Page 

Table A.1: Seasonal summary statistics for all sites______________________ IV 

Table A.2: Annual summary statistics for all sites________________________ V 

Table A.3: Summary statistics for all sites in Upper Lemon Bay ____________ VI 

Table A.4: Summary statistics for all sites in Lower Lemon Bay ___________ VII 

Table A.5: Summary statistics for all sites in Upper Charlotte Harbor _______ VIII 

Table A.6: Summary statistics for all sites in Lower Charlotte Harbor ________ IX 

Table A.7: Summary statistics for all sites in Gasparilla/Cape Haze _________ X 

Table A.8: Summary statistics for all sites in Pine Island Sound ____________ XI 

Table A.9: Summary statistics for all sites in Matlacha Pass ______________ XII 

Table A.10: Summary statistics for all sites in San Carlos Bay ____________ XIII 

Table A.11: Summary statistics for all sites in Estero Bay ________________XIV 

Table A.12: Secchi depth (m) summary and status results for each site _____ XV 

Table A.13: Temperature (°C) summary and status results for each site_____XVI 

Table A.14: Dissolved oxygen (mg/L) summary and status results for each 

 site ____________________________________________________ XVII 

Table A.15: pH summary and status results for each site _______________XVIII 

Table A.16: Salinity (ppt) summary and status results for each site_________XIX 

Table A.17: Total nitrogen (ppm) summary and status results for each site___ XX 

Table A.18: Total phosphorus (ppm) summary and status results for each 

 site _____________________________________________________XXI 

Table A.19: Chlorophyll a (μg/L) summary and status results for each site __ XXII 

Table A.20: Fecal coliform bacteria (cfu/100mL) summary and status results for 

 each site________________________________________________XXIII 

Table A.21: Turbidity (NTU) summary and status results for each site ____ XXIV 

Table A.22: Color (PCU) summary and status results for each site _________ XV 
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

IV 

 Secchi Temp DO pH Salinity TN TP ChlA Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) (cfu/100mL) (NTU) (PCU)

All N 1903 3438 3374 3400 3404 2402 2540 2310 2839 2720 2721

Min 0.0 4.0 0.6 5.8 0.0 0.032 0.005 0.01 1 0.1 1

Max 4.5 32.0 10.0 9.0 42.0 4.602 1.500 114.00 1720 120.0 400

Median 1.2 24.5 5.1 8.2 28.9 0.827 0.090 4.79 8 2.7 26

Mean 1.3 23.7 5.0 8.1 25.9 0.887 0.142 6.70 38 3.5 39

SE 0.0 0.1 0.0 0.0 0.2 0.010 0.003 0.16 2 0.1 1

Rainy N 925 1404 1374 1390 1390 956 1009 898 1156 1082 1083

Min 0.0 20.0 0.6 6.7 0.0 0.032 0.005 0.01 1 0.1 1

Max 3.9 32.0 8.9 9.0 41.6 4.302 1.000 82.10 1720 120.0 400

Median 1.1 28.0 4.3 8.2 25.9 0.952 0.092 6.02 8 2.6 40

Mean 1.2 27.9 4.2 8.1 23.6 1.019 0.159 8.02 38 3.3 54

SE 0.0 0.0 0.0 0.0 0.3 0.017 0.005 0.27 3 0.1 2

Dry N 978 2034 2000 2010 2014 1446 1531 1412 1683 1638 1638

Min 0.1 4.0 0.6 5.8 0.0 0.053 0.005 0.01 1 0.1 1

Max 4.5 30.0 10.0 9.0 42.0 4.602 1.500 114.00 1100 66.0 250

Median 1.2 21.0 5.7 8.2 30.1 0.775 0.085 3.97 8 2.7 20

Mean 1.3 20.9 5.6 8.2 27.6 0.800 0.131 5.87 37 3.6 28

SE 0.0 0.1 0.0 0.0 0.2 0.011 0.004 0.20 2 0.1 1

Table A.1: Seasonal summary statistics for all sites 
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

V 

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) (cfu/100mL) (NTU) (PCU)

1998 N 190 289 282 283 284 136 117 137 149 31 31

Med 1.0 25.5 4.9 8.2 24.7 1.06 0.08 7.75 10 3.4 25

Min 0.4 15.5 1.2 7.0 0.0 0.67 0.01 0.50 1 0.8 10

Max 3.0 31.0 8.8 8.6 40.2 1.91 0.67 82.10 480 9.2 110

SE 0.0 0.2 0.1 0.0 0.6 0.02 0.01 0.94 5 0.4 4

1999 N 240 413 398 404 403 359 322 361 357 363 362

Med 1.2 24.5 5.1 8.2 29.4 1.00 0.11 4.91 8 3.3 25

Min 0.3 7.5 0.6 7.2 0.0 0.35 0.02 0.50 1 0.3 1

Max 3.2 31.5 7.8 8.7 40.3 3.84 0.72 73.10 1156 52.0 280

SE 0.0 0.2 0.1 0.0 0.5 0.02 0.01 0.46 6 0.2 2

2000 N 264 451 443 447 447 136 298 339 371 353 354

Med 1.3 24.0 5.1 8.3 32.8 0.88 0.07 4.65 4 3.6 15

Min 0.3 10.0 1.0 6.4 0.8 0.11 0.01 0.50 1 0.1 1

Max 3.3 32.0 9.0 8.7 41.0 2.00 0.75 79.46 776 24.0 250

SE 0.0 0.2 0.1 0.0 0.4 0.03 0.01 0.43 3 0.2 1

2001 N 257 431 426 427 426 149 164 291 330 334 334

Med 1.0 22.0 5.0 8.2 32.5 0.92 0.08 2.50 12 3.2 25

Min 0.4 12.0 1.4 5.8 0.0 0.08 0.01 0.25 1 0.6 3

Max 3.9 32.0 8.7 8.6 42.0 2.42 0.78 88.50 880 30.0 220

SE 0.0 0.2 0.1 0.0 0.5 0.04 0.01 0.40 5 0.2 2

2002 N 242 473 467 467 471 416 420 416 419 419

Med 1.3 25.5 5.0 8.2 30.0 0.52 0.09 8 1.6 13

Min 0.2 11.0 1.1 7.0 0.3 0.05 0.01 1 0.1 1

Max 3.3 32.0 8.7 8.8 41.6 2.40 1.08 800 18.1 132

SE 0.0 0.2 0.1 0.0 0.4 0.02 0.01 7 0.1 1

2003 N 230 467 459 461 464 374 375 374 375 375 376

Med 1.3 25.0 5.1 8.2 26.9 0.55 0.06 6.20 4 1.9 30

Min 0.4 4.0 0.6 7.0 0.0 0.06 0.00 0.01 1 0.1 1

Max 3.8 30.0 9.9 8.7 39.4 2.96 0.90 34.18 240 120.0 360

SE 0.0 0.2 0.1 0.0 0.4 0.03 0.01 0.30 2 0.4 2

2004 N 218 431 426 426 427 371 382 346 381 383 383

Med 1.3 25.0 5.1 8.2 27.7 0.81 0.11 3.72 10 2.9 30

Min 0.1 13.0 0.7 6.8 0.0 0.37 0.03 0.50 1 0.7 10

Max 3.5 31.5 10.0 8.8 40.7 4.60 1.50 53.70 1720 26.0 400

SE 0.0 0.2 0.1 0.0 0.5 0.02 0.01 0.32 6 0.1 3

2005 N 262 483 473 485 482 461 462 462 460 462 462

Med 1.1 23.5 5.4 8.0 23.8 0.92 0.11 4.61 8 2.3 50

Min 0.0 14.5 1.0 6.7 0.0 0.03 0.01 0.58 1 0.7 10

Max 4.5 31.0 9.1 9.0 37.2 4.30 1.30 114.00 1100 28.0 240

SE 0.0 0.2 0.1 0.0 0.5 0.02 0.01 0.40 4 0.1 2

Table A.2: Annual summary statistics for all sites 
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

VI 

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) cfu/100mL (NTU) (PCU)

All N 161 381 373 377 376 219 228 209 252 240 239

Mean 0.9 23.7 4.1 8.0 22.4 1.035 0.199 9.22 98 2.9 38

Median 0.9 24.5 3.9 8.0 25.3 1.005 0.180 6.30 35 2.5 30

SE 0.0 0.2 0.1 0.0 0.6 0.031 0.007 0.60 10 0.3 2

Rain N 104 160 155 158 157 90 92 81 104 95 94

Mean 0.8 27.6 3.2 7.9 20.0 1.226 0.227 12.63 94 2.9 55

Median 0.9 28.0 3.0 8.0 22.9 1.205 0.210 9.28 40 2.6 40

SE 0.0 0.2 0.1 0.0 1.0 0.054 0.010 1.23 16 0.1 5

Dry N 57 221 218 219 219 129 136 128 148 145 145

Mean 0.9 20.9 4.7 8.0 24.2 0.901 0.181 7.06 101 3.0 27

Median 0.9 21.0 4.5 8.0 27.0 0.905 0.165 5.73 32 2.5 20

SE 0.0 0.2 0.1 0.0 0.6 0.032 0.010 0.51 13 0.4 2

1998 N 10 19 19 19 18 13 12 13 13 3 3

Mean 0.6 25.6 3.2 8.2 21.4 1.264 0.193 20.30 95 5.5 35

Median 0.6 26.5 3.1 8.2 25.5 1.250 0.170 16.40 28 4.2 30

SE 0.1 0.7 0.2 0.1 2.2 0.039 0.020 2.89 37 1.9 8

1999 N 19 48 46 48 48 35 29 34 34 32 31

Mean 0.9 23.3 3.8 8.0 23.6 1.208 0.214 11.26 160 3.5 36

Median 0.9 24.0 3.6 8.0 26.3 1.205 0.200 8.35 69 3.5 30

SE 0.0 0.6 0.2 0.1 1.5 0.035 0.012 1.69 42 0.2 3

2000 N 20 53 52 53 52 12 25 28 32 29 29

Mean 1.0 23.2 4.2 8.2 27.4 1.037 0.145 8.82 61 3.2 25

Median 1.0 24.0 3.9 8.2 31.2 1.017 0.140 6.16 23 2.7 20

SE 0.0 0.7 0.2 0.0 1.3 0.071 0.010 2.11 16 0.2 3

2001 N 26 52 51 52 50 16 18 28 30 32 32

Mean 0.7 23.3 3.9 8.0 25.3 1.173 0.209 6.27 116 3.0 38

Median 0.7 22.8 3.5 8.0 27.4 1.028 0.180 4.00 60 2.6 30

SE 0.0 0.6 0.2 0.0 1.6 0.086 0.023 1.23 36 0.2 6

2002 N 20 51 51 49 51 34 34 34 34 34

Mean 0.9 24.5 4.0 8.0 24.2 0.673 0.221 107 1.7 15

Median 0.9 26.0 3.6 8.0 28.5 0.589 0.190 20 1.4 11

SE 0.0 0.7 0.3 0.1 1.4 0.084 0.032 34 0.1 2

2003 N 24 54 51 53 54 30 30 30 30 30 30

Mean 0.9 24.0 4.3 7.9 19.7 1.007 0.149 9.10 71 4.2 31

Median 0.9 25.8 4.2 8.0 21.7 0.605 0.125 7.11 46 2.4 24

SE 0.0 0.6 0.2 0.0 1.4 0.153 0.021 0.99 13 2.1 3

2004 N 13 48 48 48 48 32 33 29 33 33 33

Mean 0.9 24.1 4.0 8.0 22.0 0.957 0.194 6.49 96 3.1 37

Median 0.9 26.0 4.0 8.0 25.0 0.883 0.180 5.17 21 2.7 30

SE 0.1 0.6 0.2 0.0 1.4 0.060 0.010 0.92 32 0.2 3

2005 N 29 56 55 55 55 47 47 47 46 47 47

Mean 1.0 22.9 4.6 7.9 16.0 1.126 0.236 9.09 79 2.2 68

Median 1.0 23.0 4.3 7.8 14.9 1.113 0.210 6.34 29 2.1 50

SE 0.0 0.6 0.2 0.1 1.5 0.037 0.016 1.10 14 0.1 8

Table A.3: Summary statistics for all sites in Upper Lemon Bay
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

VII 

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) cfu/100mL (NTU) (PCU)

All N 230 525 515 520 518 265 275 255 302 296 296

Mean 1.3 23.6 4.7 8.3 31.7 0.790 0.084 5.55 41 3.1 25

Median 1.3 24.0 4.8 8.3 33.5 0.767 0.070 3.92 8 2.6 15

SE 0.0 0.2 0.1 0.0 0.3 0.025 0.003 0.42 5 0.1 2

Rain N 116 209 203 206 207 109 108 101 120 118 118

Mean 1.3 28.0 3.9 8.2 29.9 0.930 0.083 7.30 54 2.9 38

Median 1.3 28.0 4.1 8.2 32.1 0.892 0.080 5.83 12 2.5 25

SE 0.0 0.1 0.1 0.0 0.6 0.044 0.004 0.88 11 0.1 3

Dry N 114 316 312 314 311 156 167 154 182 178 178

Mean 1.3 20.7 5.1 8.3 32.9 0.692 0.084 4.40 32 3.2 16

Median 1.3 20.3 5.2 8.4 33.8 0.725 0.070 3.20 8 2.7 15

SE 0.0 0.2 0.1 0.0 0.2 0.027 0.004 0.37 4 0.1 1

1998 N 21 23 23 22 22 13 11 14 14 3 3

Mean 1.3 25.5 5.1 8.4 33.1 0.955 0.077 8.14 9 3.8 12

Median 1.4 25.0 5.4 8.4 33.8 0.905 0.080 7.12 5 3.4 10

SE 0.1 0.8 0.3 0.0 0.5 0.042 0.007 1.55 4 0.4 2

1999 N 37 60 56 58 57 40 34 39 37 39 39

Mean 1.4 24.3 4.5 8.2 33.0 1.003 0.093 5.79 42 4.4 21

Median 1.3 24.8 4.8 8.2 33.9 0.970 0.075 3.92 8 3.8 15

SE 0.1 0.5 0.2 0.0 0.6 0.044 0.008 1.03 18 0.4 3

2000 N 35 67 65 66 67 10 26 30 29 31 31

Mean 1.3 23.0 4.7 8.3 34.6 0.963 0.070 8.21 40 3.9 16

Median 1.3 23.5 5.1 8.4 35.0 0.845 0.070 5.21 8 3.7 10

SE 0.0 0.6 0.2 0.0 0.4 0.122 0.005 2.54 11 0.3 2

2001 N 38 67 66 67 67 12 13 28 31 31 31

Mean 1.1 22.7 4.7 8.2 32.2 0.897 0.091 4.82 40 3.4 32

Median 1.0 22.0 4.7 8.2 35.0 0.783 0.080 2.75 12 2.8 19

SE 0.1 0.6 0.2 0.0 0.9 0.093 0.014 1.31 11 0.4 6

2002 N 28 79 76 78 79 43 44 43 44 44

Mean 1.5 24.0 4.5 8.3 31.1 0.437 0.080 63 2.3 10

Median 1.5 25.0 4.5 8.3 32.1 0.425 0.070 8 1.8 9

SE 0.1 0.6 0.2 0.0 0.6 0.057 0.010 26 0.3 1

2003 N 28 79 79 79 79 43 43 43 43 43 43

Mean 1.4 23.9 4.7 8.2 31.3 0.767 0.059 6.98 26 2.8 21

Median 1.3 26.0 4.7 8.2 33.2 0.550 0.060 5.56 3 2.4 17

SE 0.1 0.6 0.2 0.0 0.7 0.092 0.006 0.78 7 0.3 2

2004 N 25 75 75 74 73 41 41 38 42 42 42

Mean 1.4 23.5 4.5 8.2 31.7 0.697 0.094 2.89 35 3.2 24

Median 1.4 26.0 4.5 8.2 33.5 0.614 0.087 2.18 11 2.9 20

SE 0.1 0.5 0.2 0.0 0.7 0.035 0.005 0.36 8 0.2 3

2005 N 18 75 75 76 74 63 63 63 63 63 63

Mean 1.3 22.8 4.8 8.3 28.1 0.891 0.097 4.67 48 2.4 42

Median 1.2 23.0 5.1 8.4 31.4 0.805 0.081 3.87 16 2.1 30

SE 0.1 0.5 0.2 0.0 1.0 0.042 0.007 0.41 8 0.1 5

Table A.4: Summary statistics for all sites in Lower Lemon Bay
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

VIII 

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) cfu/100mL (NTU) (PCU)

All N 394 657 650 657 649 505 532 482 587 556 557

Mean 0.9 23.6 5.2 7.7 17.3 1.040 0.305 9.48 48 3.2 70

Median 0.9 24.0 5.2 7.8 17.9 0.975 0.240 6.16 24 2.7 50

SE 0.0 0.2 0.1 0.0 0.4 0.022 0.009 0.50 4 0.1 3

Rain N 189 263 263 262 261 200 207 187 239 221 222

Mean 0.9 27.7 4.1 7.6 13.7 1.202 0.363 9.68 51 3.1 104

Median 0.8 28.0 4.0 7.6 12.4 1.206 0.320 6.73 28 2.6 80

SE 0.0 0.1 0.1 0.0 0.6 0.035 0.014 0.76 6 0.2 5

Dry N 205 394 387 395 388 305 325 295 348 335 335

Mean 1.0 20.9 6.0 7.8 19.7 0.934 0.269 9.35 46 3.2 49

Median 1.0 21.0 6.0 7.8 21.6 0.895 0.200 5.89 22 2.8 40

SE 0.0 0.2 0.1 0.0 0.4 0.027 0.012 0.67 4 0.1 2

1998 N 63 83 81 83 81 31 23 34 34 7 7

Mean 0.9 24.6 5.0 7.6 11.6 1.295 0.257 16.57 53 4.0 56

Median 0.8 24.5 4.8 7.6 10.9 1.135 0.240 14.30 35 4.7 50

SE 0.1 0.4 0.2 0.0 0.9 0.054 0.031 2.80 11 0.5 9

1999 N 51 81 78 78 78 82 71 81 81 78 78

Mean 1.0 24.1 4.9 7.8 18.0 1.331 0.278 9.65 48 3.4 80

Median 0.9 24.0 5.1 7.8 20.1 1.310 0.250 5.97 20 2.8 55

SE 0.0 0.5 0.1 0.0 1.0 0.034 0.019 1.34 10 0.2 7

2000 N 48 79 79 79 79 33 72 67 73 70 70

Mean 1.0 23.2 5.1 7.8 23.4 0.997 0.198 8.45 37 3.7 48

Median 1.0 24.0 5.1 7.8 26.4 0.935 0.140 5.61 16 3.5 35

SE 0.0 0.5 0.2 0.0 1.0 0.048 0.017 1.30 11 0.2 5

2001 N 42 79 80 79 78 31 36 60 70 71 71

Mean 0.8 23.0 5.0 7.8 21.5 1.073 0.254 7.36 69 3.3 56

Median 0.8 22.5 5.0 7.8 24.5 1.020 0.190 3.77 41 3.1 33

SE 0.0 0.5 0.2 0.0 1.3 0.077 0.029 1.66 9 0.2 6

2002 N 39 80 81 81 79 81 81 80 81 81

Mean 0.9 23.9 5.1 7.8 19.0 0.556 0.335 79 2.0 32

Median 0.9 25.8 5.1 7.8 20.9 0.525 0.270 29 1.6 23

SE 0.1 0.5 0.1 0.0 1.1 0.043 0.023 16 0.1 3

2003 N 42 78 77 79 78 71 71 70 71 71 72

Mean 1.0 23.4 5.3 7.7 14.8 0.956 0.277 8.69 30 2.4 67

Median 0.9 25.0 5.1 7.6 16.1 0.790 0.210 7.67 20 1.9 51

SE 0.1 0.6 0.2 0.0 1.0 0.069 0.025 0.76 4 0.2 6

2004 N 51 88 88 88 87 87 88 80 88 88 88

Mean 1.0 23.5 5.5 7.8 17.6 1.134 0.363 8.67 50 4.1 96

Median 0.9 25.0 5.8 7.8 19.6 0.942 0.305 5.51 24 3.1 60

SE 0.1 0.4 0.2 0.0 0.9 0.062 0.027 0.97 10 0.4 8

2005 N 58 89 86 90 89 89 90 90 90 90 90

Mean 1.0 23.3 5.7 7.7 13.1 1.103 0.386 11.11 25 3.4 105

Median 0.9 23.0 5.6 7.8 13.3 1.001 0.325 7.78 15 3.0 80

SE 0.1 0.5 0.2 0.0 0.9 0.043 0.026 1.15 3 0.2 6

Table A.5: Summary statistics for all sites in Upper Charlotte Harbor
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

IX 

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) cfu/100mL (NTU) (PCU)

All N 105 252 247 249 248 207 215 198 234 226 226

Mean 1.8 23.9 5.4 8.3 28.2 0.792 0.114 5.61 13 2.5 30

Median 1.5 24.5 5.5 8.2 29.0 0.755 0.100 4.42 3 2.1 24

SE 0.1 0.3 0.1 0.0 0.4 0.028 0.005 0.35 2 0.2 2

Rain N 60 109 106 106 107 84 85 80 98 92 92

Mean 1.6 28.1 4.7 8.2 26.1 0.939 0.128 6.25 12 2.6 42

Median 1.4 28.0 4.7 8.2 26.4 0.910 0.110 5.73 2 2.1 35

SE 0.1 0.2 0.1 0.0 0.7 0.048 0.008 0.47 4 0.3 3

Dry N 45 143 141 143 141 123 130 118 136 134 134

Mean 2.0 20.8 5.8 8.3 29.9 0.692 0.104 5.17 13 2.5 21

Median 1.8 21.0 5.9 8.4 29.8 0.735 0.094 3.49 4 2.0 19

SE 0.1 0.3 0.1 0.0 0.4 0.030 0.005 0.49 2 0.2 1

1998 N 8 22 20 22 22 15 12 15 15 3 3

Mean 1.4 26.8 4.8 8.3 25.5 1.020 0.084 9.20 25 1.2 22

Median 1.1 28.3 5.0 8.2 27.6 1.005 0.080 7.80 4 1.0 20

SE 0.3 0.7 0.2 0.0 1.2 0.060 0.008 1.61 11 0.3 4

1999 N 11 34 32 34 31 32 30 33 30 34 34

Mean 2.1 24.3 5.2 8.4 27.6 1.049 0.122 4.61 23 3.4 28

Median 2.1 24.0 5.1 8.4 29.2 1.005 0.110 3.98 4 2.4 25

SE 0.2 0.7 0.2 0.0 1.3 0.048 0.010 0.59 12 0.6 2

2000 N 11 33 33 32 32 16 27 30 32 31 31

Mean 2.2 23.3 5.4 8.5 32.7 0.890 0.066 3.63 9 3.0 16

Median 2.3 24.0 5.7 8.6 33.5 0.870 0.060 3.45 2 2.6 15

SE 0.3 0.9 0.2 0.0 0.7 0.080 0.005 0.49 2 0.4 2

2001 N 16 31 29 29 31 14 15 25 27 27 27

Mean 1.5 22.9 4.8 8.2 31.4 0.826 0.092 4.54 18 3.8 31

Median 1.2 22.5 5.1 8.2 33.8 0.815 0.080 4.30 4 3.2 20

SE 0.2 0.8 0.3 0.0 1.2 0.092 0.010 0.64 6 0.6 5

2002 N 14 32 32 33 32 33 33 33 33 33

Mean 1.6 24.7 5.4 8.4 30.0 0.490 0.126 14 1.8 15

Median 1.4 27.0 5.5 8.4 30.4 0.525 0.120 4 1.1 14

SE 0.2 0.9 0.3 0.0 1.0 0.071 0.010 5 0.2 2

2003 N 20 34 34 33 34 30 31 31 31 31 31

Mean 1.5 23.2 5.5 8.3 26.7 0.707 0.078 8.08 5 1.9 33

Median 1.4 24.5 5.8 8.3 27.5 0.550 0.070 7.31 2 1.7 30

SE 0.1 0.8 0.3 0.0 0.9 0.104 0.008 1.29 1 0.2 3

2004 N 11 30 31 30 30 31 31 28 30 31 31

Mean 1.8 24.0 5.5 8.2 27.1 0.796 0.143 5.63 10 2.2 43

Median 1.4 25.8 5.6 8.2 28.2 0.746 0.095 3.90 3 2.2 30

SE 0.3 0.7 0.2 0.1 1.1 0.058 0.017 0.85 3 0.2 7

2005 N 14 36 36 36 36 36 36 36 36 36 36

Mean 2.1 23.4 5.9 8.1 24.5 0.756 0.156 6.02 6 1.9 42

Median 1.7 23.5 6.0 8.2 24.5 0.741 0.135 4.51 1 1.6 30

SE 0.3 0.8 0.2 0.0 0.8 0.046 0.013 0.78 2 0.2 4

Table A.6: Summary statistics for all sites in Lower Charlotte Harbor
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

X 

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) cfu/100mL (NTU) (PCU)

All N 86 192 188 194 192 141 150 145 169 162 162

Mean 1.5 24.2 4.6 8.3 31.5 0.906 0.093 4.49 20 3.3 24

Median 1.5 25.0 4.6 8.2 33.2 0.806 0.080 3.58 6 2.7 20

SE 0.1 0.3 0.1 0.0 0.4 0.042 0.005 0.31 3 0.2 1

Rain N 44 82 79 83 82 58 60 57 67 65 65

Mean 1.4 28.4 4.1 8.2 29.9 0.984 0.104 5.64 19 3.0 32

Median 1.5 28.3 4.4 8.2 31.7 0.849 0.080 4.74 4 2.7 30

SE 0.1 0.2 0.1 0.0 0.8 0.061 0.010 0.51 5 0.2 3

Dry N 42 110 109 111 110 83 90 88 102 97 97

Mean 1.6 21.1 5.0 8.3 32.7 0.851 0.085 3.74 21 3.5 19

Median 1.4 21.0 4.9 8.2 33.8 0.775 0.070 3.02 6 2.7 15

SE 0.1 0.4 0.1 0.0 0.4 0.057 0.006 0.36 4 0.3 1

1998 N 9 21 21 21 21 11 10 12 12 3 3

Mean 1.4 26.6 4.1 8.3 32.1 1.017 0.075 6.39 10 3.3 18

Median 1.3 28.0 4.2 8.2 32.5 0.895 0.075 5.43 4 3.7 15

SE 0.1 0.7 0.3 0.0 1.1 0.103 0.009 1.25 4 0.6 6

1999 N 16 32 31 33 32 26 28 29 30 30 30

Mean 1.9 24.2 5.3 8.3 33.1 0.864 0.099 5.14 13 4.0 20

Median 1.7 25.0 5.9 8.4 33.9 0.855 0.095 3.87 4 3.8 15

SE 0.1 0.9 0.3 0.1 0.6 0.035 0.009 0.78 3 0.4 3

2000 N 12 25 25 26 25 9 17 22 24 23 23

Mean 1.3 24.3 4.7 8.4 35.5 0.779 0.058 4.13 14 4.4 13

Median 1.2 24.0 4.6 8.4 36.3 0.775 0.050 3.10 3 3.5 10

SE 0.1 0.9 0.2 0.0 0.6 0.064 0.007 0.67 7 0.6 1

2001 N 12 24 23 24 24 9 10 19 20 21 21

Mean 1.3 23.0 4.5 8.2 32.0 1.239 0.082 3.79 17 4.4 23

Median 1.2 21.8 4.5 8.2 34.4 0.955 0.080 2.40 5 3.0 20

SE 0.1 1.0 0.3 0.1 1.5 0.223 0.013 0.84 6 1.3 3

2002 N 7 20 21 20 20 19 20 18 20 20

Mean 1.3 24.4 4.5 8.3 30.8 0.571 0.093 49 1.5 13

Median 1.4 26.5 4.5 8.3 32.3 0.625 0.065 16 1.1 11

SE 0.3 1.1 0.3 0.0 1.2 0.077 0.018 17 0.1 2

2003 N 3 14 14 14 14 12 12 12 12 12 12

Mean 1.1 23.0 4.9 8.2 30.6 0.828 0.051 6.68 11 2.4 20

Median 1.0 24.5 4.5 8.2 31.7 0.550 0.050 6.40 9 2.4 18

SE 0.2 1.5 0.4 0.1 1.6 0.193 0.010 1.24 3 0.3 2

2004 N 10 22 21 22 22 24 22 20 22 22 22

Mean 1.5 25.3 4.3 8.2 31.8 0.967 0.112 3.48 39 3.3 34

Median 1.5 26.3 3.9 8.2 32.2 0.744 0.087 3.34 13 3.4 30

SE 0.1 0.8 0.3 0.0 1.0 0.109 0.017 0.62 13 0.2 4

2005 N 17 34 32 34 34 31 31 31 31 31 31

Mean 1.5 23.3 4.5 8.2 26.9 1.030 0.117 4.19 12 2.6 38

Median 1.6 24.0 4.6 8.2 28.2 0.806 0.095 3.59 4 2.2 30

SE 0.1 0.8 0.2 0.1 1.1 0.110 0.013 0.63 2 0.2 4

Table A.7: Summary statistics for all sites in Gasparilla/Cape Haze
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XI 

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) cfu/100mL (NTU) (PCU)

All N 167 400 392 388 399 309 330 298 383 368 369

Mean 1.4 23.6 5.7 8.4 32.2 0.808 0.073 6.52 13 3.7 25

Median 1.3 24.5 5.9 8.4 32.9 0.752 0.060 4.98 2 2.6 18

SE 0.0 0.2 0.1 0.0 0.2 0.027 0.004 0.34 2 0.2 1

Rain N 87 164 160 160 163 121 132 118 158 148 149

Mean 1.5 27.8 5.1 8.4 30.6 0.904 0.079 8.87 11 3.5 31

Median 1.3 28.0 5.2 8.4 30.8 0.805 0.060 7.07 2 2.4 25

SE 0.1 0.1 0.1 0.0 0.5 0.050 0.008 0.58 3 0.3 2

Dry N 80 236 232 228 236 188 198 180 225 220 220

Mean 1.3 20.7 6.1 8.4 33.2 0.747 0.068 4.98 13 3.8 20

Median 1.3 20.5 6.4 8.4 33.7 0.717 0.060 3.57 2 2.7 15

SE 0.1 0.2 0.1 0.0 0.2 0.029 0.003 0.38 2 0.2 2

1998 N 9 21 21 19 21 14 11 12 14 2 2

Mean 1.0 24.6 5.6 8.4 31.2 1.242 0.058 11.81 25 3.2 20

Median 1.1 24.5 5.7 8.3 30.4 1.175 0.060 6.82 8 3.2 20

SE 0.1 0.9 0.2 0.0 0.7 0.070 0.009 3.33 10 2.2 5

1999 N 14 37 37 33 37 36 33 37 37 38 38

Mean 1.3 24.0 5.6 8.4 32.8 0.995 0.074 7.40 13 4.1 21

Median 1.2 24.5 5.5 8.4 32.9 0.935 0.070 6.17 4 3.5 20

SE 0.1 0.7 0.2 0.0 0.5 0.044 0.006 0.90 5 0.4 2

2000 N 28 57 57 57 57 13 35 50 56 52 53

Mean 1.4 23.3 5.8 8.5 35.4 0.853 0.066 6.59 5 5.3 12

Median 1.3 23.5 5.8 8.4 35.8 0.845 0.060 4.86 2 4.0 10

SE 0.1 0.7 0.2 0.0 0.3 0.087 0.005 0.74 1 0.5 1

2001 N 32 52 52 50 52 21 22 41 48 47 47

Mean 1.1 22.7 6.1 8.4 34.4 0.948 0.057 5.03 17 6.2 23

Median 1.1 22.0 6.2 8.4 35.9 0.915 0.050 3.10 2 4.4 20

SE 0.1 0.6 0.2 0.0 0.7 0.092 0.005 0.92 5 0.7 2

2002 N 32 68 63 66 68 67 67 67 67 67

Mean 1.5 23.8 5.5 8.3 33.0 0.483 0.065 22 3.0 14

Median 1.4 25.0 6.1 8.5 33.7 0.480 0.050 2 1.7 7

SE 0.1 0.6 0.2 0.0 0.5 0.036 0.005 7 0.4 2

2003 N 15 65 62 62 64 60 60 60 60 60 60

Mean 1.9 23.4 5.5 8.4 30.2 0.668 0.052 7.77 8 1.9 29

Median 1.8 25.0 5.8 8.6 31.1 0.550 0.035 5.83 1 1.7 20

SE 0.2 0.6 0.3 0.0 0.6 0.067 0.006 0.73 3 0.2 2

2004 N 12 40 41 41 40 37 41 37 40 41 41

Mean 1.8 23.5 5.5 8.3 31.6 0.787 0.084 4.19 6 3.1 34

Median 1.8 25.0 5.7 8.4 33.1 0.762 0.072 3.20 1 2.7 20

SE 0.2 0.7 0.3 0.1 0.7 0.050 0.007 0.64 2 0.3 5

2005 N 25 60 59 60 60 61 61 61 61 61 61

Mean 1.3 24.0 5.8 8.3 28.6 1.049 0.105 6.89 12 3.1 40

Median 1.3 25.0 6.1 8.4 30.2 0.940 0.068 4.90 1 2.2 30

SE 0.1 0.6 0.2 0.1 0.7 0.072 0.017 0.81 5 0.5 5

Table A.8: Summary statistics for all sites in Pine Island Sound
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XII 

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) cfu/100mL (NTU) (PCU)

All N 202 261 252 250 258 194 212 187 234 221 221

Mean 1.6 24.0 5.5 8.2 21.7 0.905 0.084 5.42 9 2.5 37

Median 1.6 24.5 5.5 8.2 22.1 0.851 0.076 3.50 4 2.1 30

SE 0.0 0.3 0.1 0.0 0.5 0.032 0.003 0.52 1 0.1 2

Rain N 84 106 103 104 105 76 86 71 95 85 85

Mean 1.4 28.2 4.6 8.1 18.7 1.021 0.094 7.89 11 3.0 51

Median 1.3 28.0 4.8 8.1 17.3 0.975 0.090 5.31 3 2.5 45

SE 0.1 0.2 0.1 0.0 0.8 0.051 0.005 1.16 2 0.2 4

Dry N 118 155 149 146 153 118 126 116 139 136 136

Mean 1.8 21.1 6.1 8.2 23.7 0.831 0.076 3.90 8 2.1 28

Median 1.9 21.0 6.1 8.2 24.2 0.793 0.070 3.00 4 2.0 25

SE 0.0 0.3 0.1 0.0 0.6 0.041 0.004 0.38 1 0.1 2

1998 N 24 32 30 31 32 12 11 11 15 3 3

Mean 1.3 25.5 4.9 8.1 18.1 1.089 0.073 7.33 9 2.2 42

Median 1.4 25.3 4.9 8.0 19.3 1.105 0.070 5.31 8 2.1 40

SE 0.1 0.7 0.2 0.0 1.0 0.033 0.006 1.84 2 0.2 2

1999 N 28 32 31 31 31 30 29 31 30 32 32

Mean 1.7 23.9 5.2 8.1 21.7 1.224 0.099 6.91 10 2.9 42

Median 1.7 23.5 5.6 8.1 20.4 1.167 0.080 3.10 4 2.5 30

SE 0.1 0.7 0.3 0.0 1.3 0.103 0.009 2.33 3 0.3 5

2000 N 31 35 35 34 35 15 31 30 34 32 32

Mean 1.7 24.0 5.3 8.3 26.2 1.018 0.062 4.50 9 2.7 20

Median 1.7 24.0 5.1 8.2 26.8 0.905 0.053 3.20 2 2.4 20

SE 0.1 0.8 0.2 0.0 0.8 0.072 0.005 0.54 3 0.2 2

2001 N 24 32 32 32 31 14 14 27 28 28 28

Mean 1.6 23.4 5.4 8.1 27.5 0.952 0.076 3.75 14 3.1 29

Median 1.6 22.3 5.3 8.2 31.1 0.923 0.070 2.30 6 2.6 24

SE 0.1 0.8 0.2 0.0 1.7 0.110 0.008 0.87 3 0.3 3

2002 N 26 34 34 32 34 34 35 35 34 34

Mean 1.7 24.7 5.4 8.1 23.6 0.532 0.093 10 1.6 19

Median 1.6 26.5 5.3 8.2 26.5 0.525 0.080 3 1.1 14

SE 0.1 0.9 0.3 0.0 1.3 0.040 0.009 3 0.2 2

2003 N 26 34 34 32 34 30 30 30 30 30 30

Mean 1.8 23.5 6.1 8.2 18.4 0.848 0.059 7.64 5 1.9 39

Median 1.8 24.8 6.0 8.2 20.0 0.550 0.045 5.58 1 1.6 33

SE 0.1 0.9 0.2 0.0 1.1 0.120 0.008 1.09 3 0.2 4

2004 N 24 32 27 29 31 29 32 28 32 32 32

Mean 1.6 24.2 5.6 8.3 21.3 0.856 0.094 4.11 10 2.6 50

Median 1.8 25.0 5.8 8.4 21.8 0.793 0.085 3.38 2 2.3 40

SE 0.1 0.7 0.3 0.0 1.0 0.048 0.006 0.63 3 0.3 6

2005 N 19 30 29 29 30 30 30 30 30 30 30

Mean 1.4 22.7 6.4 8.1 16.3 0.963 0.102 5.05 5 2.7 60

Median 1.4 23.0 6.5 8.1 15.3 0.967 0.086 2.65 4 2.2 50

SE 0.1 0.8 0.2 0.1 1.4 0.049 0.010 1.22 1 0.2 6

Table A.9: Summary statistics for all sites in Matlacha Pass
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XIII 

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) cfu/100mL (NTU) (PCU)

All N 327 340 334 339 339 249 263 245 310 294 294

Mean 1.5 24.1 5.9 8.3 29.1 0.755 0.069 4.41 12 4.2 27

Median 1.4 24.8 5.9 8.2 30.6 0.753 0.060 3.43 2 3.2 20

SE 0.0 0.3 0.1 0.0 0.4 0.025 0.002 0.25 2 0.4 1

Rain N 135 138 135 139 137 93 104 94 125 117 117

Mean 1.4 28.4 5.3 8.3 27.4 0.869 0.069 5.58 12 4.5 36

Median 1.3 28.5 5.3 8.2 28.9 0.845 0.061 4.89 2 3.2 26

SE 0.0 0.1 0.1 0.0 0.6 0.046 0.003 0.43 3 1.0 3

Dry N 192 202 199 200 202 156 159 151 185 177 177

Mean 1.5 21.2 6.3 8.3 30.2 0.688 0.069 3.68 11 4.1 21

Median 1.5 22.0 6.2 8.2 31.5 0.676 0.060 2.91 3 3.2 16

SE 0.0 0.3 0.1 0.0 0.4 0.028 0.003 0.28 2 0.2 1

1998 N 35 39 39 39 39 13 14 15 18 4 4

Mean 1.1 26.2 5.8 8.3 27.2 0.957 0.054 6.00 28 4.2 19

Median 1.1 26.0 5.8 8.2 27.7 0.915 0.050 5.90 2 3.3 18

SE 0.1 0.6 0.1 0.0 0.9 0.061 0.004 0.86 20 1.1 2

1999 N 42 45 45 45 45 43 37 42 44 45 45

Mean 1.4 24.4 5.7 8.3 29.1 0.983 0.095 5.07 13 4.5 31

Median 1.4 24.5 5.7 8.2 30.8 0.880 0.080 3.68 4 4.1 25

SE 0.1 0.6 0.2 0.0 1.0 0.055 0.007 0.82 3 0.3 4

2000 N 47 48 44 47 47 14 31 43 47 44 44

Mean 1.6 24.1 6.0 8.4 32.5 0.899 0.057 3.44 7 4.8 12

Median 1.5 24.5 6.1 8.4 32.8 0.890 0.050 3.20 2 4.2 10

SE 0.1 0.7 0.1 0.0 0.5 0.051 0.004 0.29 1 0.4 1

2001 N 43 44 44 44 44 20 20 33 40 40 40

Mean 1.2 23.4 5.8 8.3 32.6 0.823 0.064 3.22 16 6.0 25

Median 1.1 22.8 5.8 8.2 34.5 0.835 0.057 2.50 4 5.2 20

SE 0.1 0.7 0.1 0.0 1.0 0.075 0.006 0.44 7 0.6 3

2002 N 43 44 44 44 44 45 45 45 45 45

Mean 1.4 24.4 5.7 8.3 30.1 0.385 0.066 15 2.3 13

Median 1.4 25.8 5.6 8.4 31.4 0.370 0.060 2 2.0 10

SE 0.1 0.8 0.2 0.0 0.8 0.039 0.005 5 0.2 2

2003 N 40 43 42 43 42 39 39 39 39 39 39

Mean 1.8 23.7 6.2 8.3 27.1 0.739 0.048 6.75 10 5.1 29

Median 1.7 25.5 6.2 8.2 27.7 0.550 0.030 5.65 2 1.9 23

SE 0.1 0.8 0.1 0.0 1.0 0.094 0.007 0.80 4 3.0 3

2004 N 35 37 36 35 37 33 35 31 35 35 35

Mean 1.9 23.6 5.8 8.3 29.7 0.656 0.070 2.95 9 3.4 33

Median 1.9 25.0 5.9 8.2 30.6 0.617 0.064 2.23 2 3.0 30

SE 0.1 0.8 0.2 0.0 1.0 0.036 0.004 0.54 2 0.3 5

2005 N 42 40 40 42 41 42 42 42 42 42 42

Mean 1.4 23.4 6.2 8.1 23.6 0.870 0.084 4.22 5 3.6 50

Median 1.4 24.0 6.0 8.0 24.3 0.862 0.070 3.28 2 3.0 50

SE 0.1 0.8 0.2 0.0 1.1 0.037 0.009 0.41 1 0.3 4

Table A.10: Summary statistics for all sites in San Carlos Bay
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XIV 

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

(m) (C) (mg/L) (ppt) (ppm) (ppm) (μg/L) cfu/100mL (NTU) (PCU)

All N 177 361 356 357 357 276 297 263 331 319 319

Mean 1.2 23.6 4.7 8.1 27.5 0.790 0.070 5.75 44 5.6 31

Median 1.1 25.0 4.8 8.2 30.4 0.762 0.060 4.39 10 4.2 30

SE 0.0 0.2 0.1 0.0 0.5 0.027 0.003 0.50 5 0.3 1

Rain N 82 148 146 147 147 113 122 101 137 128 128

Mean 1.2 27.5 3.9 8.1 24.9 0.894 0.064 5.95 32 3.8 42

Median 1.2 27.5 3.9 8.1 27.7 0.897 0.056 5.53 8 3.3 33

SE 0.0 0.1 0.1 0.0 0.8 0.049 0.003 0.42 5 0.2 2

Dry N 95 213 210 210 210 163 175 162 194 191 191

Mean 1.2 20.9 5.3 8.2 29.4 0.718 0.074 5.63 52 6.7 25

Median 1.1 21.0 5.2 8.2 32.0 0.707 0.061 3.90 14 5.1 20

SE 0.0 0.2 0.1 0.0 0.5 0.028 0.004 0.78 8 0.4 1

1998 N 9 26 25 24 26 14 13 11 14 3 3

Mean 1.0 26.2 4.0 8.2 30.0 1.068 0.062 7.74 29 6.5 20

Median 1.0 28.0 4.3 8.2 31.9 0.982 0.050 7.69 20 6.1 15

SE 0.1 0.7 0.3 0.0 1.0 0.068 0.006 0.86 8 0.9 5

1999 N 15 35 34 35 35 35 31 35 34 35 35

Mean 1.0 24.2 4.6 8.1 29.3 0.963 0.096 6.32 43 7.4 35

Median 1.0 25.0 4.8 8.2 31.5 0.965 0.080 4.97 10 5.2 30

SE 0.0 0.7 0.2 0.0 1.2 0.029 0.009 0.88 14 1.4 5

2000 N 24 44 43 43 43 14 34 39 44 41 41

Mean 1.0 23.2 4.9 8.3 32.7 0.961 0.071 5.25 14 7.7 19

Median 1.0 23.3 4.9 8.2 34.6 0.925 0.065 4.65 4 6.6 15

SE 0.1 0.7 0.2 0.0 0.7 0.119 0.005 0.82 3 0.7 2

2001 N 17 42 42 42 41 11 15 29 35 36 36

Mean 0.9 22.6 4.6 8.1 29.5 0.977 0.053 4.07 65 7.4 35

Median 0.8 22.0 4.7 8.2 31.6 0.735 0.060 3.20 16 5.3 30

SE 0.1 0.6 0.2 0.0 1.5 0.193 0.004 0.70 18 0.9 4

2002 N 25 55 55 54 54 51 52 52 52 52

Mean 1.2 24.2 4.5 8.1 28.4 0.441 0.074 69 3.1 14

Median 1.2 25.5 4.4 8.2 30.6 0.425 0.065 11 2.7 12

SE 0.1 0.6 0.2 0.0 1.2 0.049 0.006 22 0.3 1

2003 N 28 59 59 59 58 53 53 53 53 53 53

Mean 1.5 23.8 4.8 8.1 25.6 0.723 0.040 6.70 25 3.7 27

Median 1.6 25.0 4.6 8.2 28.5 0.550 0.030 5.74 8 2.2 22

SE 0.1 0.6 0.2 0.0 1.3 0.069 0.004 0.78 5 0.6 2

2004 N 28 48 48 48 48 47 48 45 48 48 48

Mean 1.4 23.1 4.9 8.1 25.8 0.811 0.085 4.65 44 5.9 41

Median 1.5 24.5 4.9 8.1 28.3 0.730 0.075 3.05 14 4.6 35

SE 0.1 0.5 0.2 0.1 1.5 0.032 0.010 0.75 10 0.7 3

2005 N 31 52 50 52 52 51 51 51 51 51 51

Mean 1.3 22.7 5.1 8.0 22.2 0.905 0.071 6.83 53 5.4 50

Median 1.2 23.0 5.0 8.0 25.3 0.882 0.050 4.20 7 4.4 50

SE 0.1 0.6 0.2 0.0 1.5 0.072 0.009 2.17 16 0.6 3

Table A.11: Summary statistics for all sites in Estero Bay
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XV 

Table A.12: Secchi depth (m) summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 45 0.5 1.4 0.9 0.0 0.9 11 40 average

LBGOT2 27 0.5 1.3 0.9 0.0 0.8 5 40 average

LBV001 37 0.5 1.2 0.9 0.0 0.9 11 40 average

LBV002 33 0.4 1.6 0.8 0.0 0.8 5 40 average

LBV003 19 0.4 1.3 0.8 0.1 0.8 5 40 average

GSV002 53 0.6 2.0 1.4 0.0 1.5 37 80 higher than average

LBANG1 25 0.6 1.5 1.1 0.0 1.2 27 60 average

LBOYS1 16 0.7 3.3 1.3 0.1 1.2 27 60 average

LBV004 37 0.7 2.1 1.1 0.1 1.2 27 60 average

LBV005 59 0.5 2.2 1.4 0.1 1.4 33 80 higher than average

LBV006 7 0.6 1.2 0.9 0.1 0.9 11 40 average

LBV007 33 1.0 1.9 1.4 0.0 1.4 34 80 higher than average

CHV001 83 0.6 2.3 1.3 0.0 1.2 27 60 average

CHV002 50 0.4 2.3 1.0 0.1 0.9 11 40 average

CHV003 15 0.5 1.0 0.8 0.0 0.7 3 30 lower than average

CHV004 49 0.4 1.4 0.8 0.0 0.9 11 40 average

CHV005 42 0.4 1.8 0.9 0.1 0.8 5 40 average

CHV006 53 0.1 1.5 0.8 0.0 0.8 5 40 average

CHV007 42 0.4 1.6 1.0 0.0 1.1 22 60 average

CHV008 8 0.5 1.3 0.8 0.1 0.8 5 40 average

CHV013 52 0.4 2.7 0.7 0.0 0.7 3 30 lower than average

CHV009 20 0.7 1.5 1.1 0.1 1.1 22 60 average

CHV010 26 0.5 2.1 1.2 0.1 1.1 22 60 average

CHV011 59 0.7 4.5 2.3 0.1 2.3 48 100 higher than average

CHV012 46 0.2 2.5 1.4 0.1 1.5 37 80 higher than average

GSV001 6 0.0 1.5 0.9 0.2 1.0 18 50 average

GSV003 23 1.1 3.2 1.7 0.1 1.4 33 80 higher than average

GSV004 11 1.0 1.8 1.5 0.1 1.5 37 80 higher than average

PIJIM1 2 0.1 0.5 0.3 0.2 0.3 1 20 lower than average

PIV001 40 0.8 2.3 1.4 0.1 1.4 33 80 higher than average

PIV002 28 0.6 1.4 1.0 0.0 1.0 18 50 average

PIV004 45 0.5 3.9 1.9 0.1 1.8 46 90 higher than average

PIV006 46 0.4 2.0 1.2 0.1 1.2 27 60 average

PIV007 6 0.8 1.5 1.1 0.1 1.0 18 50 average

MPV001 52 0.8 2.7 1.6 0.1 1.6 42 80 higher than average

MPV002 92 0.7 3.1 1.6 0.1 1.6 42 80 higher than average

MPV003 58 0.4 3.8 1.7 0.1 1.8 46 90 higher than average

EBV001 86 0.5 3.3 1.2 0.0 1.1 22 60 average

MPV004 85 0.6 2.7 1.6 0.1 1.6 42 80 higher than average

SCV001 89 0.7 3.5 1.5 0.1 1.5 37 80 higher than average

SCV002 67 0.5 3.9 1.7 0.1 1.6 42 80 higher than average

EBERS2 51 1.0 1.8 1.5 0.0 1.5 37 80 higher than average

EBV003 16 0.6 1.1 0.8 0.0 0.9 11 40 average

EBV004 45 0.4 1.8 1.0 0.0 1.0 18 50 average

EBV005 20 0.3 1.6 0.8 0.1 0.9 11 40 average

EBV006 15 0.6 1.7 1.0 0.1 1.1 22 60 average

EBV007 30 0.5 2.9 1.4 0.1 1.3 32 80 higher than average

Outside of estuary GSV005 54 0.3 0.9 0.6 0.0 0.6 2 30 lower than average

All sites 1903 0.0 4.5 1.3 0.0 1.2 60 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***below average < 40, 40 < average < 70, above average > 70

Upper Lemon 

Bay

Lower Lemon 

Bay

Upper Charlotte 

Harbor

San Carlos Bay

Lower Charlotte 

Harbor

Estero Bay

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XVI 

Table A.13: Temperature (°C) summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 53 15.0 32.0 24.5 0.7 26.0 46 70 higher than average

LBGOT2 71 13.5 30.0 23.3 0.5 25.0 30 60 average

LBV001 85 15.5 30.0 24.1 0.5 24.5 19 60 average

LBV002 87 13.5 30.0 23.4 0.5 24.5 19 60 average

LBV003 85 12.0 32.0 23.3 0.5 24.0 4 60 average

GSV002 77 14.0 31.0 23.7 0.6 24.0 4 60 average

LBANG1 76 13.0 30.0 23.3 0.5 24.0 4 60 average

LBOYS1 75 13.0 32.0 23.7 0.6 25.0 30 60 average

LBV004 86 12.0 30.0 22.9 0.5 23.5 2 60 average

LBV005 75 14.0 30.0 23.7 0.5 24.0 4 60 average

LBV006 66 10.0 31.0 23.3 0.6 23.8 3 60 average

LBV007 70 14.0 31.5 24.5 0.6 25.3 45 70 higher than average

CHV001 86 11.0 31.0 23.9 0.5 24.0 4 60 average

CHV002 49 14.0 30.0 23.5 0.6 24.0 4 60 average

CHV003 64 13.0 29.0 23.4 0.5 25.0 30 60 average

CHV004 88 4.0 30.0 23.4 0.5 24.8 28 60 average

CHV005 42 14.0 31.5 24.1 0.7 24.3 16 60 average

CHV006 88 9.0 30.5 23.4 0.5 24.0 4 60 average

CHV007 96 14.0 31.0 23.4 0.5 24.0 4 60 average

CHV008 90 15.0 31.5 24.1 0.5 24.5 19 60 average

CHV013 54 14.0 29.5 23.4 0.6 24.5 19 60 average

CHV009 85 13.5 31.0 23.8 0.5 25.0 30 60 average

CHV010 87 13.0 31.5 23.6 0.5 24.0 4 60 average

CHV011 80 13.5 31.5 24.5 0.5 25.0 30 60 average

CHV012 65 14.5 30.0 24.3 0.6 25.0 30 60 average

GSV001 85 7.5 31.5 24.1 0.6 25.0 30 60 average

GSV003 25 19.0 31.0 24.7 0.8 25.0 30 60 average

GSV004 17 16.0 30.0 23.7 1.1 26.0 46 70 higher than average

PIJIM1 35 13.0 30.0 23.0 0.8 25.0 30 60 average

PIV001 65 14.0 30.0 23.4 0.6 24.5 19 60 average

PIV002 93 14.0 31.0 23.5 0.5 24.5 19 60 average

PIV004 61 15.0 30.5 24.0 0.6 24.0 4 60 average

PIV006 83 14.0 30.5 24.1 0.5 24.5 19 60 average

PIV007 63 10.5 31.0 23.1 0.6 25.0 30 60 average

MPV001 88 14.5 30.5 23.7 0.5 24.3 16 60 average

MPV002 94 13.5 31.0 24.1 0.5 24.8 28 60 average

MPV003 79 14.0 31.0 24.1 0.5 25.0 30 60 average

EBV001 89 13.0 31.0 24.3 0.5 25.0 30 60 average

MPV004 88 14.0 31.0 24.1 0.5 24.3 16 60 average

SCV001 87 10.0 31.0 23.3 0.5 24.5 19 60 average

SCV002 76 14.5 31.0 24.9 0.5 25.0 30 60 average

EBERS2 51 15.5 28.0 23.6 0.5 25.0 30 60 average

EBV003 61 15.0 29.0 24.8 0.5 26.0 46 70 higher than average

EBV004 87 14.0 30.5 23.3 0.5 24.0 4 60 average

EBV005 92 14.5 31.0 23.2 0.5 24.0 4 60 average

EBV006 23 14.5 28.5 21.9 1.0 23.0 1 50 average

EBV007 47 14.5 31.0 24.1 0.7 25.0 30 60 average

Outside of estuary GSV005 69 14.0 31.0 23.2 0.5 24.5 19 60 average

All sites 3438 4.0 32.0 23.8 0.1 24.5 60 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***lower average < 40, 40 < average < 70, higher than average > 70

Upper Lemon 

Bay

Lower Lemon 

Bay

Estero Bay

Upper Charlotte 

Harbor

Lower Charlotte 

Harbor

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass

San Carlos Bay
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XVII 

Table A.14: Dissolved oxygen (mg/L) summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 53 2.2 8.8 4.6 0.2 4.3 12 20 lower than average

LBGOT2 67 1.0 8.6 3.6 0.2 3.4 5 10 lower than average

LBV001 85 1.1 6.9 3.2 0.1 3.0 4 10 lower than average

LBV002 85 2.2 8.3 4.9 0.2 4.9 18 20 lower than average

LBV003 83 1.9 7.6 4.2 0.2 3.9 7 10 lower than average

GSV002 73 1.5 7.7 5.2 0.1 5.2 28 30 lower than average

LBANG1 75 1.0 8.2 4.2 0.2 3.9 7 10 lower than average

LBOYS1 75 1.7 8.2 4.3 0.1 4.1 11 20 lower than average

LBV004 85 2.7 7.8 4.9 0.1 4.9 18 20 lower than average

LBV005 72 2.8 7.7 5.5 0.1 5.6 35 30 lower than average

LBV006 63 0.6 5.3 2.8 0.2 2.3 2 10 lower than average

LBV007 72 3.4 7.5 5.5 0.1 5.5 33 30 lower than average

CHV001 84 2.3 8.6 5.1 0.1 5.0 24 20 lower than average

CHV002 50 2.6 9.5 6.1 0.2 6.1 43 40 average

CHV003 64 0.6 8.4 4.8 0.2 4.7 15 20 lower than average

CHV004 86 2.5 8.7 5.4 0.1 5.3 29 30 lower than average

CHV005 42 2.6 8.8 5.3 0.2 5.1 27 30 lower than average

CHV006 89 2.8 8.6 5.7 0.1 5.8 39 40 average

CHV007 93 2.7 7.8 5.0 0.1 4.9 18 20 lower than average

CHV008 90 2.0 7.4 4.5 0.1 4.4 13 20 lower than average

CHV013 52 1.4 9.9 5.1 0.2 4.9 18 20 lower than average

CHV009 83 2.5 7.9 5.0 0.1 5.0 24 20 lower than average

CHV010 86 2.4 7.9 4.8 0.1 4.9 18 20 lower than average

CHV011 78 4.2 9.1 6.3 0.1 6.3 45 50 average

CHV012 63 2.0 7.2 5.4 0.1 5.6 35 30 lower than average

GSV001 85 1.4 6.9 4.0 0.1 4.0 9 20 lower than average

GSV003 23 3.4 7.3 5.5 0.2 5.4 32 30 lower than average

GSV004 17 2.7 5.2 3.8 0.2 3.6 6 10 lower than average

PIJIM1 32 0.6 5.9 2.1 0.2 1.7 1 10 lower than average

PIV001 63 2.3 8.2 5.9 0.1 5.8 39 40 average

PIV002 93 3.2 9.0 5.9 0.1 5.9 42 40 average

PIV004 61 4.1 8.7 6.8 0.1 7.0 48 70 higher than average

PIV006 82 3.8 8.9 6.5 0.1 6.6 47 60 average

PIV007 61 2.5 7.3 4.7 0.1 4.8 16 20 lower than average

MPV001 84 2.0 8.6 5.8 0.1 5.8 39 40 average

MPV002 91 2.3 9.0 5.0 0.1 5.0 24 20 lower than average

MPV003 77 3.4 8.6 5.9 0.1 5.6 35 30 lower than average

EBV001 86 3.3 8.7 5.6 0.1 5.5 33 30 lower than average

MPV004 87 2.8 8.3 5.6 0.1 5.6 35 30 lower than average

SCV001 87 4.2 8.1 6.1 0.1 6.1 43 40 average

SCV002 74 3.0 8.2 6.3 0.1 6.3 45 50 average

EBERS2 51 1.5 7.0 4.0 0.2 4.0 9 10 lower than average

EBV003 61 2.1 7.9 4.5 0.2 4.6 14 20 lower than average

EBV004 86 1.2 7.5 4.9 0.1 4.9 18 20 lower than average

EBV005 90 2.0 7.5 4.6 0.1 4.8 16 20 lower than average

EBV006 22 4.2 10.0 5.7 0.3 5.3 29 30 lower than average

EBV007 46 3.6 7.6 5.3 0.2 5.3 29 30 lower than average

Outside of estuary GSV005 67 1.2 8.1 3.2 0.2 2.9 3 10 lower than average

All sites 3374 0.6 10.0 5.0 0.0 5.1 30 lower than average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***below average < 40, 40 < average < 70, above average > 70

Estero Bay

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass

San Carlos Bay

Upper Lemon 

Bay

Lower Lemon 

Bay

Upper Charlotte 

Harbor

Lower Charlotte 

Harbor
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XVIII 

Table A.15: pH summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 51 7.2 8.3 8.0 0.0 8.0 13 60 average

LBGOT2 70 7.2 8.0 7.6 0.0 7.6 3 20 lower than average

LBV001 85 7.2 8.2 7.8 0.0 7.8 8 50 average

LBV002 86 7.3 8.8 8.3 0.0 8.3 33 90 higher than average

LBV003 85 7.8 8.6 8.3 0.0 8.2 21 80 higher than average

GSV002 72 7.8 8.6 8.3 0.0 8.4 34 100 higher than average

LBANG1 76 7.2 8.6 8.1 0.0 8.2 21 90 higher than average

LBOYS1 74 7.4 8.6 8.0 0.0 8.0 13 60 average

LBV004 86 7.8 8.6 8.4 0.0 8.4 34 100 higher than average

LBV005 75 8.1 8.6 8.5 0.0 8.6 46 100 higher than average

LBV006 65 7.2 8.6 7.9 0.0 8.0 13 60 average

LBV007 72 8.2 9.0 8.5 0.0 8.5 42 100 higher than average

CHV001 86 7.0 8.0 7.7 0.0 7.8 8 40 average

CHV002 50 7.2 8.6 7.9 0.1 8.0 13 60 average

CHV003 64 7.2 8.0 7.6 0.0 7.6 3 20 lower than average

CHV004 89 5.8 8.6 7.8 0.0 7.8 8 40 average

CHV005 40 7.2 8.0 7.4 0.0 7.4 2 10 lower than average

CHV006 88 6.4 8.6 7.9 0.0 8.0 13 60 average

CHV007 96 7.2 8.6 7.9 0.0 7.9 12 50 average

CHV008 90 7.0 8.3 7.8 0.0 7.8 8 40 average

CHV013 54 6.7 8.1 7.4 0.0 7.3 1 10 lower than average

CHV009 85 7.4 8.6 8.1 0.0 8.2 21 90 higher than average

CHV010 85 8.0 8.6 8.4 0.0 8.4 34 100 higher than average

CHV011 79 7.8 8.6 8.4 0.0 8.4 34 100 higher than average

CHV012 65 7.4 8.6 8.2 0.0 8.2 21 90 higher than average

GSV001 87 7.2 8.6 8.2 0.0 8.2 21 90 higher than average

GSV003 25 7.2 8.6 8.5 0.1 8.6 46 100 higher than average

GSV004 17 7.6 8.6 8.2 0.1 8.2 21 90 higher than average

PIJIM1 35 7.0 8.4 7.7 0.1 7.6 3 20 lower than average

PIV001 66 7.9 8.7 8.5 0.0 8.5 42 100 higher than average

PIV002 90 8.0 8.7 8.4 0.0 8.4 34 100 higher than average

PIV004 60 7.4 8.7 8.4 0.0 8.5 42 100 higher than average

PIV006 76 7.4 8.8 8.4 0.0 8.5 42 100 higher than average

PIV007 61 8.0 8.7 8.5 0.0 8.6 46 100 higher than average

MPV001 84 7.5 8.6 8.2 0.0 8.2 21 90 higher than average

MPV002 89 7.4 8.6 8.1 0.0 8.1 20 80 higher than average

MPV003 77 7.8 8.6 8.2 0.0 8.2 21 90 higher than average

EBV001 89 7.8 8.6 8.2 0.0 8.2 21 90 higher than average

MPV004 87 7.4 8.6 8.2 0.0 8.2 21 90 higher than average

SCV001 89 8.0 8.6 8.4 0.0 8.4 34 100 higher than average

SCV002 74 7.5 8.6 8.3 0.0 8.2 21 90 higher than average

EBERS2 51 7.2 8.2 7.6 0.0 7.6 3 20 lower than average

EBV003 57 7.6 8.4 8.0 0.0 8.0 13 70 average

EBV004 87 8.0 8.8 8.4 0.0 8.4 34 100 higher than average

EBV005 92 7.6 8.4 8.1 0.0 8.0 13 70 average

EBV006 23 8.2 8.6 8.4 0.0 8.4 34 100 higher than average

EBV007 47 8.0 8.7 8.3 0.0 8.2 21 90 higher than average

Outside of estuary GSV005 69 7.2 8.4 7.6 0.0 7.6 3 20 lower than average

All sites 3400 5.8 9.0 8.1 0.0 8.2 90 higher than average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***lower average < 40, 40 < average < 70, higher than average > 70

Estero Bay

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass

San Carlos Bay

Upper Lemon 

Bay

Lower Lemon 

Bay

Upper Charlotte 

Harbor

Lower Charlotte 

Harbor
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XIX 

Table A.16: Salinity (ppt) summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 53 1.0 35.5 22.9 1.4 26.5 18 70 higher than average

LBGOT2 67 0.0 35.5 11.0 1.1 9.3 3 20 lower than average

LBV001 85 1.4 33.0 16.5 0.9 17.9 8 40 average

LBV002 87 6.4 38.1 28.1 0.7 29.6 21 70 higher than average

LBV003 84 22.0 40.7 31.4 0.5 31.9 32 80 higher than average

GSV002 77 20.6 38.9 33.6 0.4 34.5 44 100 higher than average

LBANG1 76 3.1 39.3 29.6 0.8 32.2 33 80 higher than average

LBOYS1 73 7.5 39.8 30.5 0.7 32.2 33 80 higher than average

LBV004 85 15.8 39.8 32.5 0.4 33.4 39 100 higher than average

LBV005 72 24.4 38.2 33.6 0.4 34.8 48 100 higher than average

LBV006 65 2.1 40.7 27.5 1.2 30.0 25 70 higher than average

LBV007 70 7.0 38.8 33.9 0.5 34.5 44 100 higher than average

CHV001 85 2.4 33.0 18.0 0.8 18.7 9 40 average

CHV002 49 1.1 28.5 13.8 1.1 13.4 5 20 lower than average

CHV003 64 2.1 30.5 14.6 1.0 16.1 7 30 lower than average

CHV004 86 2.1 36.3 19.8 1.0 20.8 11 40 average

CHV005 42 0.0 24.4 6.9 1.1 4.2 2 10 lower than average

CHV006 86 2.9 36.7 19.6 1.0 21.6 12 50 average

CHV007 95 4.5 35.5 22.8 0.7 24.3 15 60 average

CHV008 88 2.5 37.1 22.6 0.9 24.3 15 60 average

CHV013 54 0.0 17.3 4.7 0.7 2.0 1 10 lower than average

CHV009 83 8.5 38.3 26.0 0.8 26.9 19 70 higher than average

CHV010 87 17.5 39.1 29.6 0.5 29.6 21 80 higher than average

CHV011 78 9.7 38.4 29.1 0.7 30.4 27 80 higher than average

CHV012 65 16.2 38.9 29.6 0.6 29.8 24 80 higher than average

GSV001 85 10.0 40.7 32.1 0.7 34.1 43 100 higher than average

GSV003 25 32.2 40.2 35.1 0.4 34.5 44 100 higher than average

GSV004 17 10.7 35.2 30.6 1.5 32.9 38 90 higher than average

PIJIM1 34 4.5 41.6 28.7 1.3 29.6 21 80 higher than average

PIV001 65 19.6 41.2 32.9 0.5 33.4 39 100 higher than average

PIV002 93 22.5 41.1 32.4 0.4 32.5 36 90 higher than average

PIV004 61 23.3 39.7 33.5 0.4 33.5 41 100 higher than average

PIV006 83 16.6 40.1 30.6 0.6 31.3 31 90 higher than average

PIV007 63 6.6 42.0 33.7 0.7 34.6 47 100 higher than average

MPV001 85 7.2 39.8 22.8 0.8 23.3 14 50 average

MPV002 94 2.9 35.8 20.1 0.8 20.1 10 40 average

MPV003 79 4.9 37.5 22.4 0.9 22.9 13 50 average

EBV001 89 18.3 41.4 32.0 0.5 32.2 33 90 higher than average

MPV004 88 8.8 37.5 24.8 0.8 26.1 17 60 average

SCV001 88 15.8 38.0 29.6 0.6 31.0 29 90 higher than average

SCV002 74 16.2 38.9 30.1 0.6 31.0 29 90 higher than average

EBERS2 51 0.2 33.2 12.3 1.4 10.9 4 20 lower than average

EBV003 59 9.6 39.8 29.2 1.0 30.9 28 90 higher than average

EBV004 85 21.2 39.3 32.9 0.4 33.7 42 100 higher than average

EBV005 92 2.5 38.0 28.1 0.8 30.1 26 80 higher than average

EBV006 23 26.9 37.8 32.7 0.7 32.6 37 90 higher than average

EBV007 47 19.3 38.2 28.7 0.6 28.5 20 80 higher than average

Outside of estuary GSV005 68 0.8 39.3 15.8 1.4 13.9 6 30 lower than average

All sites 3404 0.0 42.0 25.9 0.2 28.9 80 higher than average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***lower average < 40, 40 < average < 70, higher than average > 70

Estero Bay

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass

San Carlos Bay

Upper Lemon 

Bay

Lower Lemon 

Bay

Upper Charlotte 

Harbor

Lower Charlotte 

Harbor
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XX 

Table A.17: Total nitrogen (ppm) summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 6 0.905 1.724 1.230 0.122 1.163 45 90 higher than average

LBGOT2 8 1.214 1.525 1.365 0.043 1.324 47 90 higher than average

LBV001 70 0.180 2.690 1.102 0.050 1.137 44 90 higher than average

LBV002 67 0.075 2.650 0.996 0.061 0.942 37 80 higher than average

LBV003 68 0.075 2.750 0.946 0.057 0.887 34 70 higher than average

GSV002 61 0.075 2.532 0.799 0.051 0.767 15 60 average

LBANG1 7 0.712 1.305 0.941 0.078 0.868 28 70 higher than average

LBOYS1 8 0.627 1.328 0.871 0.076 0.838 26 70 higher than average

LBV004 68 0.075 2.130 0.731 0.046 0.726 9 60 average

LBV005 62 0.075 1.850 0.641 0.046 0.590 2 50 average

LBV006 51 0.075 2.560 1.004 0.071 0.975 39 80 higher than average

LBV007 8 0.552 1.202 0.806 0.069 0.794 20 70 higher than average

CHV001 67 0.075 2.550 1.027 0.056 1.005 40 80 higher than average

CHV002 42 0.032 1.885 1.120 0.059 1.066 41 80 higher than average

CHV003 50 0.075 2.230 0.933 0.057 0.871 31 70 higher than average

CHV004 64 0.075 2.218 0.954 0.055 0.957 38 80 higher than average

CHV005 25 0.297 2.440 1.400 0.081 1.460 48 100 higher than average

CHV006 68 0.125 2.370 1.174 0.065 1.113 42 90 higher than average

CHV007 73 0.053 2.400 0.878 0.055 0.812 22 70 higher than average

CHV008 67 0.075 1.970 0.853 0.048 0.810 21 70 higher than average

CHV013 49 0.075 4.602 1.337 0.099 1.310 46 90 higher than average

CHV009 74 0.075 1.990 0.928 0.049 0.913 35 70 higher than average

CHV010 67 0.075 2.300 0.806 0.049 0.762 14 60 average

CHV011 66 0.055 1.710 0.625 0.037 0.561 1 50 average

CHV012 48 0.075 1.950 0.843 0.054 0.813 23 70 higher than average

GSV001 62 0.075 2.526 1.041 0.081 0.868 28 70 higher than average

GSV003 15 0.555 1.202 0.743 0.043 0.725 8 60 average

GSV004 16 0.526 1.202 0.723 0.047 0.644 6 50 average

PIJIM1 34 0.075 4.302 1.038 0.138 0.825 24 70 higher than average

PIV001 51 0.075 1.975 0.697 0.052 0.602 4 50 average

PIV002 68 0.075 1.970 0.760 0.041 0.739 11 60 average

PIV004 49 0.070 1.845 0.772 0.071 0.771 18 60 average

PIV006 61 0.065 2.510 0.875 0.059 0.935 36 80 higher than average

PIV007 46 0.055 1.530 0.784 0.047 0.782 19 60 average

MPV001 66 0.210 1.900 0.904 0.043 0.865 27 70 higher than average

MPV002 70 0.032 2.470 0.914 0.050 0.872 32 70 higher than average

MPV003 58 0.070 3.840 0.896 0.076 0.767 15 60 average

EBV001 68 0.075 1.980 0.740 0.044 0.747 12 60 average

MPV004 65 0.055 2.930 0.834 0.054 0.830 25 70 higher than average

SCV001 65 0.075 1.930 0.744 0.042 0.738 10 60 average

SCV002 51 0.075 2.815 0.690 0.062 0.630 5 50 average

EBERS2 47 0.075 2.370 0.919 0.066 0.870 30 70 higher than average

EBV003 46 0.075 2.005 0.839 0.066 0.876 33 70 higher than average

EBV004 62 0.053 4.046 0.787 0.071 0.770 17 60 average

EBV005 67 0.065 2.060 0.783 0.045 0.750 13 60 average

EBV006 14 0.085 1.102 0.691 0.082 0.719 7 60 average

EBV007 40 0.075 1.550 0.631 0.051 0.597 3 50 average

Outside of estuary GSV005 37 0.380 2.960 1.240 0.094 1.125 43 90 higher than average

All sites 2402 0.032 4.602 0.887 0.010 0.827 70 higher than average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***above average < 40, 40 < average < 70, below average > 70

Estero Bay

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass

San Carlos Bay

Upper Lemon 

Bay

Lower Lemon 

Bay

Upper Charlotte 

Harbor

Lower Charlotte 

Harbor
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXI 

Table A.18: Total phosphorus (ppm) summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 6 0.160 0.700 0.297 0.083 0.220 40 80 higher than average

LBGOT2 8 0.200 0.480 0.332 0.034 0.330 46 90 higher than average

LBV001 74 0.010 0.610 0.207 0.011 0.205 39 80 higher than average

LBV002 68 0.015 1.080 0.191 0.017 0.170 35 80 higher than average

LBV003 72 0.025 0.380 0.176 0.009 0.170 36 80 higher than average

GSV002 64 0.010 0.220 0.072 0.005 0.065 18 40 average

LBANG1 7 0.078 0.180 0.107 0.014 0.090 28 50 average

LBOYS1 8 0.049 0.120 0.078 0.008 0.077 23 50 average

LBV004 70 0.025 0.270 0.086 0.005 0.080 25 50 average

LBV005 65 0.010 0.420 0.070 0.007 0.060 8 40 average

LBV006 53 0.015 0.270 0.113 0.008 0.100 30 60 average

LBV007 8 0.038 0.086 0.058 0.007 0.055 5 40 average

CHV001 70 0.090 0.790 0.289 0.016 0.260 43 90 higher than average

CHV002 41 0.010 0.430 0.239 0.017 0.240 42 90 higher than average

CHV003 53 0.060 0.500 0.187 0.013 0.180 37 80 higher than average

CHV004 68 0.080 0.650 0.267 0.016 0.235 41 90 higher than average

CHV005 29 0.230 0.750 0.509 0.025 0.510 47 100 higher than average

CHV006 70 0.080 0.810 0.335 0.021 0.290 45 90 higher than average

CHV007 78 0.040 0.900 0.226 0.016 0.200 38 80 higher than average

CHV008 72 0.015 0.590 0.157 0.011 0.130 34 70 higher than average

CHV013 51 0.250 1.500 0.731 0.034 0.680 48 100 higher than average

CHV009 77 0.013 0.350 0.134 0.008 0.120 32 60 average

CHV010 71 0.010 0.340 0.102 0.007 0.090 29 50 average

CHV011 67 0.005 0.420 0.103 0.008 0.080 26 50 average

CHV012 49 0.025 0.350 0.131 0.010 0.120 33 60 average

GSV001 68 0.005 0.310 0.072 0.006 0.064 16 40 average

GSV003 17 0.030 0.130 0.070 0.008 0.060 9 40 average

GSV004 16 0.025 0.240 0.086 0.012 0.083 27 50 average

PIJIM1 35 0.015 0.900 0.158 0.028 0.100 31 60 average

PIV001 57 0.025 0.250 0.082 0.006 0.070 20 50 average

PIV002 70 0.005 0.230 0.068 0.005 0.060 10 40 average

PIV004 52 0.010 0.100 0.050 0.003 0.050 3 40 average

PIV006 65 0.010 0.170 0.061 0.004 0.058 6 40 average

PIV007 51 0.005 0.220 0.048 0.005 0.040 1 30 lower than average

MPV001 74 0.010 0.290 0.087 0.006 0.078 24 50 average

MPV002 76 0.010 0.260 0.083 0.005 0.073 21 50 average

MPV003 62 0.010 0.180 0.080 0.005 0.076 22 50 average

EBV001 72 0.030 0.270 0.071 0.004 0.065 17 40 average

MPV004 69 0.010 0.260 0.073 0.005 0.063 15 40 average

SCV001 68 0.010 0.220 0.063 0.004 0.060 7 40 average

SCV002 54 0.005 0.250 0.068 0.007 0.050 4 40 average

EBERS2 48 0.008 0.140 0.051 0.004 0.045 2 30 lower than average

EBV003 49 0.020 0.130 0.067 0.003 0.060 11 40 average

EBV004 68 0.010 0.500 0.074 0.008 0.060 12 40 average

EBV005 73 0.005 0.360 0.076 0.006 0.060 13 40 average

EBV006 19 0.015 0.250 0.077 0.013 0.060 14 40 average

EBV007 40 0.010 0.270 0.075 0.008 0.065 19 40 average

Outside of estuary GSV005 38 0.080 0.530 0.286 0.017 0.270 44 90 higher than average

All sites 2540 0.005 1.500 0.141 0.003 0.090 50 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***above average < 40, 40 < average < 70, below average > 70

Estero Bay

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass

San Carlos Bay

Upper Lemon 

Bay

Lower Lemon 

Bay

Upper Charlotte 

Harbor

Lower Charlotte 

Harbor
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXII 

Table A.19: Chlorophyll a (μg/L) summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 6 9.06 23.90 15.09 2.41 13.00 48 80 higher than average

LBGOT2 8 1.38 14.50 5.21 1.52 4.13 20 40 average

LBV001 65 0.50 48.73 8.43 1.02 6.00 36 50 average

LBV002 66 0.50 30.30 8.48 0.83 6.88 42 60 average

LBV003 64 1.40 52.30 10.75 1.35 6.32 37 60 average

GSV002 56 0.01 18.73 3.88 0.43 3.10 6 30 lower than average

LBANG1 7 0.71 9.54 5.73 1.10 5.94 35 50 average

LBOYS1 8 0.71 7.03 3.38 0.81 2.91 3 30 lower than average

LBV004 69 0.25 23.20 5.51 0.54 4.83 26 40 average

LBV005 56 0.50 79.46 6.73 1.57 3.60 11 30 lower than average

LBV006 51 0.25 34.60 6.54 0.79 5.51 32 50 average

LBV007 8 0.71 11.00 4.97 1.24 3.82 13 40 average

CHV001 62 0.01 65.60 12.69 1.56 8.83 44 70 higher than average

CHV002 42 1.46 42.10 9.33 1.16 6.95 43 60 average

CHV003 44 0.72 17.39 6.07 0.66 4.95 29 40 average

CHV004 64 0.50 36.50 9.32 1.02 6.52 39 60 average

CHV005 32 1.60 88.50 20.55 3.96 10.92 47 80 higher than average

CHV006 63 0.50 82.10 9.37 1.56 6.73 40 60 average

CHV007 72 0.01 28.68 6.91 0.68 5.14 30 50 average

CHV008 66 0.50 15.89 4.22 0.39 3.30 8 30 lower than average

CHV013 37 0.01 53.70 13.60 2.17 9.82 46 70 higher than average

CHV009 66 0.01 24.12 7.09 0.58 6.34 38 60 average

CHV010 68 0.01 21.20 5.19 0.51 4.01 18 40 average

CHV011 64 0.01 34.18 4.52 0.69 3.06 5 30 lower than average

CHV012 49 0.50 17.70 5.95 0.54 4.91 28 40 average

GSV001 61 0.50 16.65 3.31 0.42 2.16 1 20 lower than average

GSV003 20 0.50 15.20 4.38 0.77 3.87 14 40 average

GSV004 15 1.67 18.20 4.63 1.02 3.59 10 30 lower than average

PIJIM1 23 0.88 34.30 8.93 1.55 6.79 41 60 average

PIV001 53 0.50 27.87 4.92 0.62 4.00 17 40 average

PIV002 68 0.50 26.70 7.48 0.82 5.36 31 50 average

PIV004 46 0.25 39.70 5.36 0.93 4.16 22 40 average

PIV006 62 0.01 25.64 6.66 0.70 5.69 33 50 average

PIV007 46 0.50 26.00 6.70 0.71 5.86 34 50 average

MPV001 63 0.50 34.10 5.56 0.64 4.37 23 40 average

MPV002 70 0.25 25.43 5.62 0.66 3.62 12 30 lower than average

MPV003 54 0.50 72.50 4.78 1.40 2.57 2 20 lower than average

EBV001 66 0.25 28.35 5.13 0.50 4.15 21 40 average

MPV004 63 0.25 18.80 3.76 0.44 3.04 4 30 lower than average

SCV001 63 0.01 22.30 4.47 0.51 3.87 14 40 average

SCV002 53 0.25 24.80 4.20 0.53 3.34 9 30 lower than average

EBERS2 35 0.01 114.00 7.80 3.19 3.10 6 30 lower than average

EBV003 46 0.50 26.67 4.85 0.68 3.98 16 40 average

EBV004 66 0.01 11.92 5.21 0.36 4.81 25 40 average

EBV005 65 0.01 33.00 6.06 0.80 4.07 19 40 average

EBV006 19 0.50 15.20 5.22 0.82 4.65 24 40 average

EBV007 32 0.01 23.56 5.61 0.88 4.89 27 40 average

Outside of estuary GSV005 28 0.01 29.70 9.56 1.35 9.14 45 70 higher than average

All sites 2310 0.01 114.00 6.70 0.16 4.79 40 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***above average < 40, 40 < average < 70, below average > 70

Estero Bay

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass

San Carlos Bay

Upper Lemon 

Bay

Lower Lemon 

Bay

Upper Charlotte 

Harbor

Lower Charlotte 

Harbor
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXIII 

Table A.20: Fecal coliform bacteria (cfu/100mL) summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 6 8 120 78 22 106 44 100 higher than average

LBGOT2 8 5 170 87 21 110 45 100 higher than average

LBV001 80 1 1156 219 26 132 47 100 higher than average

LBV002 80 1 240 35 6 12 25 70 higher than average

LBV003 78 1 480 40 8 18 32 80 higher than average

GSV002 67 1 130 18 3 10 24 70 higher than average

LBANG1 7 12 180 97 22 120 46 100 higher than average

LBOYS1 8 12 228 86 27 50 40 90 higher than average

LBV004 79 1 232 16 4 4 15 50 average

LBV005 70 1 58 7 1 3 14 50 average

LBV006 63 1 800 128 20 84 42 100 higher than average

LBV007 8 1 35 8 4 2 6 40 average

CHV001 76 1 220 43 6 26 36 80 higher than average

CHV002 43 1 48 9 2 4 15 50 average

CHV003 57 1 288 54 8 36 38 90 higher than average

CHV004 77 1 296 33 6 18 32 80 higher than average

CHV005 34 2 776 104 24 60 41 90 higher than average

CHV006 79 1 180 29 4 14 28 70 higher than average

CHV007 87 1 288 42 5 30 37 80 higher than average

CHV008 82 1 800 62 15 24 35 80 higher than average

CHV013 52 1 800 89 19 49 39 90 higher than average

CHV009 78 1 152 22 4 9 23 70 higher than average

CHV010 82 1 98 10 2 4 15 50 average

CHV011 74 1 372 7 5 1 1 10 lower than average

CHV012 60 1 162 8 3 2 6 40 average

GSV001 72 1 248 30 5 16 31 70 higher than average

GSV003 21 1 79 7 4 2 6 40 average

GSV004 16 2 280 38 18 12 25 70 higher than average

PIJIM1 34 1 352 44 12 18 34 80 higher than average

PIV001 66 1 224 21 5 7 20 60 average

PIV002 84 1 122 6 2 1 1 10 lower than average

PIV004 63 1 144 9 4 1 1 10 lower than average

PIV006 76 1 260 8 4 1 1 10 lower than average

PIV007 60 1 68 4 1 1 1 10 lower than average

MPV001 79 1 60 5 1 2 6 40 average

MPV002 87 1 106 15 2 8 22 60 average

MPV003 68 1 94 6 2 2 6 40 average

EBV001 81 1 274 27 5 14 28 70 higher than average

MPV004 81 1 364 11 5 4 15 50 average

SCV001 80 1 98 4 1 2 6 40 average

SCV002 68 1 16 3 0 2 6 40 average

EBERS2 49 4 800 160 26 104 43 100 higher than average

EBV003 58 1 186 32 6 12 25 70 higher than average

EBV004 80 1 70 11 1 4 15 50 average

EBV005 83 1 384 39 8 14 28 70 higher than average

EBV006 21 1 34 7 2 2 6 40 average

EBV007 40 1 120 13 3 7 20 60 average

Outside of estuary GSV005 37 1 1720 278 61 148 48 100 higher than average

All sites 2839 1 1720 38 2 8 60 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***above average < 40, 40 < average < 70, below average > 70

Upper Lemon 

Bay

Lower Lemon 

Bay

Upper Charlotte 

Harbor

Lower Charlotte 

Harbor

Estero Bay

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass

San Carlos Bay
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXIV 

Table A.21: Turbidity (NTU) summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 6 2.0 3.6 2.7 0.2 2.7 28 50 average

LBGOT2 8 1.1 3.0 1.7 0.2 1.6 2 30 lower than average

LBV001 77 1.0 5.8 2.6 0.1 2.5 20 50 average

LBV002 76 0.5 9.2 2.7 0.2 2.5 19 50 average

LBV003 73 0.6 66.0 3.7 0.9 2.7 29 50 average

GSV002 66 0.5 9.7 3.6 0.3 3.2 37 60 average

LBANG1 7 1.4 3.6 2.4 0.3 2.2 11 40 average

LBOYS1 8 1.8 3.6 2.4 0.2 2.2 12 40 average

LBV004 77 0.5 9.0 3.0 0.2 2.9 30 50 average

LBV005 68 0.5 8.9 3.3 0.3 2.6 24 50 average

LBV006 62 1.0 9.7 2.7 0.2 2.3 13 40 average

LBV007 8 1.3 2.7 1.8 0.2 1.7 3 30 lower than average

CHV001 71 1.0 7.9 2.9 0.2 2.6 27 50 average

CHV002 38 1.3 8.1 3.8 0.3 3.5 38 60 average

CHV003 59 1.0 5.4 2.4 0.1 2.1 10 40 average

CHV004 73 0.5 23.0 3.2 0.3 3.0 32 50 average

CHV005 28 2.0 13.9 4.5 0.5 3.9 40 60 average

CHV006 75 1.0 18.0 3.6 0.3 3.0 33 50 average

CHV007 82 0.5 17.4 2.9 0.2 2.6 22 50 average

CHV008 78 0.5 7.8 2.3 0.2 2.0 6 40 average

CHV013 52 1.4 24.0 4.7 0.5 4.1 41 60 average

CHV009 77 0.5 6.5 2.3 0.1 2.1 9 40 average

CHV010 78 0.5 18.6 3.1 0.3 2.4 15 40 average

CHV011 71 0.1 21.0 2.2 0.3 1.6 1 30 lower than average

CHV012 56 0.6 7.3 2.8 0.2 2.4 18 40 average

GSV001 71 0.9 30.0 3.1 0.4 2.6 25 50 average

GSV003 19 1.0 13.8 5.4 0.7 4.9 45 70 higher than average

GSV004 16 1.6 6.4 3.3 0.3 3.2 36 60 average

PIJIM1 35 1.0 6.0 1.9 0.2 1.7 4 30 lower than average

PIV001 64 0.5 9.7 3.2 0.3 2.5 21 50 average

PIV002 79 0.3 10.2 3.0 0.3 2.3 14 40 average

PIV004 59 0.5 28.0 4.9 0.7 2.9 31 50 average

PIV006 71 0.5 26.0 5.4 0.6 3.8 39 60 average

PIV007 60 0.5 8.7 2.9 0.2 2.6 23 50 average

MPV001 74 0.3 6.6 2.3 0.1 2.0 5 40 average

MPV002 81 0.7 6.8 2.7 0.1 2.4 16 40 average

MPV003 66 0.1 10.5 2.4 0.2 2.0 8 40 average

EBV001 77 0.7 120.0 6.4 1.5 4.5 44 70 higher than average

MPV004 78 0.5 8.8 3.0 0.2 2.6 26 50 average

SCV001 75 0.5 14.7 3.9 0.3 3.1 35 50 average

SCV002 64 0.4 13.3 3.5 0.3 3.0 34 50 average

EBERS2 49 0.5 4.4 2.1 0.1 2.0 7 40 average

EBV003 55 1.0 16.9 4.9 0.4 4.4 43 70 higher than average

EBV004 75 1.0 24.0 6.2 0.5 5.2 47 70 higher than average

EBV005 79 0.1 52.0 7.2 0.8 5.0 46 70 higher than average

EBV006 21 1.0 26.0 8.9 1.4 6.7 48 80 higher than average

EBV007 40 0.5 11.3 4.7 0.4 4.2 42 70 higher than average

Outside of estuary GSV005 38 1.0 7.3 2.6 0.2 2.4 17 40 average

All sites 2720 0.1 120.0 3.5 0.1 2.7 50 average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***above average < 40, 40 < average < 70, below average > 70

Upper Lemon 

Bay

Lower Lemon 

Bay

Upper Charlotte 

Harbor

Lower Charlotte 

Harbor

Estero Bay

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass

San Carlos Bay
Appendix A CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXV 

Table A.22: Color (PCU) summary and status results for each site 

Site N Min Max Mean SE Median Rank* FL Estuaries** Status***

LBFOR1 6 30 240 78 33 50 37 80 higher than average

LBGOT2 8 80 200 123 14 110 48 100 higher than average

LBV001 77 10 120 47 3 45 35 80 higher than average

LBV002 75 5 200 30 3 23 21 60 average

LBV003 73 4 120 24 2 20 12 50 average

GSV002 66 3 100 16 2 15 3 50 average

LBANG1 7 20 240 77 29 50 37 80 higher than average

LBOYS1 8 20 160 58 17 30 24 70 higher than average

LBV004 77 3 120 21 3 15 3 50 average

LBV005 68 1 60 15 1 12 2 40 average

LBV006 62 3 100 39 3 30 24 70 higher than average

LBV007 8 10 40 23 4 20 12 50 average

CHV001 71 5 240 59 5 50 37 80 higher than average

CHV002 38 25 320 103 12 75 45 90 higher than average

CHV003 59 15 210 71 7 50 37 80 higher than average

CHV004 73 10 245 62 6 50 37 80 higher than average

CHV005 29 15 280 110 16 70 44 90 higher than average

CHV006 75 10 320 72 7 50 37 80 higher than average

CHV007 82 10 265 52 5 34 33 70 higher than average

CHV008 78 4 200 44 4 34 33 70 higher than average

CHV013 52 20 400 118 11 90 47 90 higher than average

CHV009 77 10 120 39 3 30 24 70 higher than average

CHV010 78 3 120 27 2 20 12 50 average

CHV011 71 1 140 23 3 15 3 50 average

CHV012 56 3 100 26 3 20 12 50 average

GSV001 71 5 70 24 2 20 12 50 average

GSV003 19 5 15 9 1 10 1 30 lower than average

GSV004 16 15 120 34 6 30 24 70 higher than average

PIJIM1 35 19 200 71 8 54 43 80 higher than average

PIV001 64 1 100 21 2 17 9 50 average

PIV002 80 3 60 20 1 17 9 50 average

PIV004 59 3 50 15 1 15 3 50 average

PIV006 71 3 70 23 2 20 12 50 average

PIV007 60 3 60 18 2 15 3 50 average

MPV001 74 1 160 34 3 30 24 70 higher than average

MPV002 81 6 120 39 3 33 32 70 higher than average

MPV003 66 3 160 37 4 29 23 70 higher than average

EBV001 77 3 120 26 2 20 12 50 average

MPV004 78 2 160 35 4 25 22 60 average

SCV001 75 3 140 26 3 20 12 50 average

SCV002 64 1 95 21 2 15 3 50 average

EBERS2 49 1 120 50 4 47 36 80 higher than average

EBV003 55 5 110 32 3 30 24 70 higher than average

EBV004 75 1 140 22 2 18 11 50 average

EBV005 79 1 130 32 3 30 24 70 higher than average

EBV006 21 1 40 20 2 20 12 50 average

EBV007 40 1 100 30 3 30 24 70 higher than average

Outside of estuary GSV005 38 17 360 96 11 80 46 90 higher than average

All sites 2721 1 400 39 1 26 70 higher than average

*Ranking of median value in ascending order compared to each estuary region median within the CHEVWQMN

**Median value compared to typcial Florida estuarine water quality percentile distributions (Hand 2004)

***lower average < 40, 40 < average < 70, higher than average > 70

Upper Lemon 

Bay

Lower Lemon 

Bay

Upper Charlotte 

Harbor

Lower Charlotte 

Harbor

Estero Bay

Gasparilla/Cape 

Haze

Pine Island 

Sound

Matlacha Pass

San Carlos Bay
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXVI 

Appendix B: Water Quality Comparisons 

 Page 

Table B.1: Non parametric ANOVA (Kruskal-Wallis) results between aquatic preserves 

for the entire study duration ________________________________ XXVII 

Table B.2: Non parametric t-test (Mann-Whitney) results between the rainy and dry 

season ___________________________________________XXVIII-XXIX 

Table B.3: Aquatic Preserve non parametric t-test (Mann-Whitney) post hoc 

comparisons _____________________________________ XXX-XXXVIII 
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXVII 

Table B.1: Non parametric ANOVA (Kruskal-Wallis) results between aquatic preserves for the entire study duration

 Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

Chi-Square 497 11 464 1109 1125 159 1198 157 630 209 518

df 8 8 8 8 8 8 8 8 8 8 8

p (2 tailed) 0.0000 0.2210 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

Bold values significant at the .05 level
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXVIII 

Table B.2: Non parametric t-test (Mann Whitney) results between the rainy and dry season

Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

Rain 74.3 289.6 121.3 174.1 167.6 135.52 139.70 127.5 127 129.5 155

Dry 93.2 119.6 233.7 199.8 203.5 92.19 97.46 90.8 126 114.6 97

Rain 7727.0 46333.5 18801.0 27502.5 26313.5 12197.00 12852.00 10324.5 13196 12302.5 14566

Dry 5314.0 26437.5 50950.0 43750.5 44562.5 11893.00 13254.00 11620.5 18682 16617.5 14114

Mann Whitney U 2267.0 1906.5 6711.0 14941.5 13910.5 3508.0 3938.0 3364.5 7656.0 6032.5 3529.0

Z -2.493 -14.886 -9.927 -2.280 -3.157 -4.979 -4.749 -4.272 -0.070 -1.626 -6.316

p (2 tailed)* 0.0130 0.0000 0.0000 0.0226 0.0016 0.0000 0.0000 0.0001 0.9440 0.1040 0.0000

Rain 112.3 411.0 185.2 244.3 233.6 159.22 141.13 157.7 155 144.0 192

Dry 118.7 165.1 305.4 271.1 276.7 114.68 135.97 108.5 149 151.5 120

Rain 13031.0 85904.0 37600.0 50332.0 48352.5 17355.00 15242.50 15925.5 18626 16988.0 22611

Dry 13534.0 52171.0 95270.0 85128.0 86068.5 17890.00 22707.50 16714.5 27128 26968.0 21346

Mann Whitney U 6245.0 2085.0 16894.0 29011.0 26824.5 5644.0 8679.5 4779.5 10474.5 9967.0 5414.5

Z -0.731 -18.212 -8.956 -2.024 -3.215 -4.656 -0.526 -5.204 -0.602 -0.742 -7.099

p (2 tailed)* 0.4649 0.0000 0.0000 0.0430 0.0013 0.0000 0.5986 0.0000 0.5470 0.4580 0.0000

Rain 171.4 512.2 175.3 246.9 255.4 302.77 321.20 253.1 301 265.2 369

Dry 221.6 206.7 427.6 383.4 371.9 220.37 231.66 234.1 289 287.3 219

Rain 32390.0 134707.0 46099.5 64699.5 66646.0 60553.00 66488.00 47337.0 71999 58605.0 81893

Dry 45425.0 81446.0 165475.5 151453.5 144279.0 67212.00 75290.00 69066.0 100580 96241.0 73510

Mann Whitney U 14435.0 3631.0 11383.5 30246.5 32455.0 20547.0 22315.0 25406.0 39853.5 34074.0 17230.0

Z -4.390 -20.247 -16.817 -9.142 -7.762 -6.206 -6.552 -1.461 -0.859 -1.588 -10.744

p (2 tailed)* 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.1440 0.3905 0.1123 0.0000

Rain 46.8 193.4 89.6 111.0 103.0 122.72 120.85 113.4 113 113.0 146

Dry 61.3 75.5 149.9 135.4 140.8 91.22 99.60 90.1 121 113.8 91

Rain 2807.5 21079.0 9495.5 11760.5 11018.0 10308.50 10272.50 9071.5 11094 10395.5 13422

Dry 2757.5 10799.0 21132.5 19364.5 19858.0 11219.50 12947.50 10629.5 16401 15255.5 12230

Mann Whitney U 977.5 503.0 3824.5 6089.5 5240.0 3593.5 4432.5 3608.5 6243.0 6117.5 3184.5

Z -2.415 -12.740 -6.567 -2.707 -4.117 -3.716 -2.454 -2.810 -0.841 -0.096 -6.192

p (2 tailed)* 0.0158 0.0000 0.0000 0.0068 0.0000 0.0002 0.0141 0.0050 0.4005 0.9232 0.0000

Rain 41.2 148.8 75.1 92.2 86.3 79.72 82.23 88.3 81 81.4 101

Dry 45.9 57.5 108.6 101.4 104.1 64.90 71.02 63.1 87 81.5 69

Rain 1813.0 12203.5 5929.5 7655.5 7080.0 4624.00 4933.50 5030.0 5459 5293.5 6556

Dry 1928.0 6324.5 11836.5 11259.5 11448.0 5387.00 6391.50 5555.0 8907 7909.5 6647

Mann Whitney U 823.0 219.5 2769.5 4169.5 3677.0 1901.0 2296.5 1639.0 3180.5 3148.5 1894.0

Z -0.875 -11.286 -4.172 -1.162 -2.187 -2.120 -1.550 -3.521 -0.765 -0.014 -4.337

p (2 tailed)* 0.3815 0.0000 0.0000 0.2452 0.0287 0.0343 0.1210 0.0000 0.4440 0.9891 0.0000

*Bold values significant at the .05 level

Mean 

Rank

Sum of

Ranks

Mean 

Rank

Mean 

Rank

Sum of

Ranks

Mean 

Rank

Sum of

Ranks

Sum of

Ranks

Mean 

Rank

Sum of

Ranks

Lower 

Lemon 

Bay

Upper 

Lemon 

Bay

Upper 

Charlotte 

Harbor

Lower 

Charlotte 

Harbor

Gasparilla/

Cape 

Haze
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXIX 

Table B.2, cont.

Secchi Temp DO pH Salinity TN TP Chl a Coliform Turbidity Color

Rain 86.4 309.1 145.4 189.9 166.2 170.38 167.47 195.8 189 178.1 223

Dry 81.4 125.0 231.7 197.8 223.3 145.10 164.19 119.2 194 188.8 159

Rain 7513.5 50697.0 23262.5 30375.5 27093.5 20616.00 22105.50 23101.5 29805 26354.0 33186

Dry 6514.5 29503.0 53765.5 45090.5 52706.5 27279.00 32509.50 21449.5 43732 41542.0 35080

Mann Whitney U 3274.5 1537.0 10382.5 17495.5 13727.5 9513.0 12808.5 5159.5 17243.5 15328.0 10769.5

Z -0.660 -15.693 -7.419 -0.697 -4.863 -2.428 -0.306 -7.036 -0.526 -0.952 -5.625

p (2 tailed)* 0.5092 0.0000 0.0000 0.4856 0.0000 0.0151 0.7594 0.0000 0.5991 0.3413 0.0000

Rain 73.0 204.0 77.6 105.5 101.3 113.30 123.94 117.5 118 133.2 143

Dry 121.8 81.1 160.3 139.7 148.8 87.32 94.60 79.7 117 97.1 91

Rain 6135.5 21618.5 7991.0 10976.0 10639.5 8611.00 10658.50 8339.0 11241 11326.0 12172

Dry 14367.5 12572.5 23887.0 20399.0 22771.5 10304.00 11919.50 9239.0 16254 13205.0 12360

Mann Whitney U 2565.5 482.5 2635.0 5516.0 5074.5 3283.0 3918.5 2453.0 6524.0 3889.0 3043.5

Z -5.848 -12.931 -8.861 -3.780 -5.024 -3.147 -3.426 -4.062 -0.157 -4.091 -5.936

p (2 tailed)* 0.0000 0.0000 0.0000 0.0002 0.0000 0.0016 0.0006 0.0000 0.8749 0.0000 0.0000

Rain 149.3 266.2 108.3 160.0 146.9 145.78 137.77 152.0 157 138.9 176

Dry 174.3 105.1 207.7 176.9 185.7 112.61 128.23 104.9 154 153.2 129

Rain 20157.5 36742.0 14616.5 22245.0 20120.0 13557.50 14328.00 14288.5 19678 16250.0 20541

Dry 33470.5 21228.0 41328.5 35385.0 37510.0 17567.50 20388.00 15846.5 28528 27115.0 22824

Mann Whitney U 10977.5 725.0 5436.5 12515.0 10667.0 5321.5 7668.0 4370.5 11322.5 9347.0 7071.0

Z -2.360 -14.863 -9.239 -1.614 -3.580 -3.515 -0.998 -4.687 -0.317 -1.412 -4.618

p (2 tailed)* 0.0183 0.0000 0.0000 0.1066 0.0003 0.0004 0.3185 0.0000 0.7516 0.1579 0.0000

Rain 90.3 279.8 114.1 167.3 147.4 157.23 137.21 152.6 155 125.1 197

Dry 87.9 112.3 223.3 187.2 201.2 125.51 157.22 119.2 174 183.4 135

Rain 7406.0 41411.5 16657.0 24591.0 21661.5 17768.00 16740.00 15410.5 21253 16012.5 25254

Dry 8347.0 23929.5 46889.0 39312.0 42241.5 20458.00 27513.00 19305.5 33694 35027.5 25787

Mann Whitney U 3787.0 1138.5 5926.0 13713.0 10783.5 7092.0 9237.0 6102.5 11799.5 7756.5 7450.5

Z -0.319 -15.023 -9.850 -1.830 -4.847 -3.248 -1.980 -3.465 -1.742 -5.533 -5.933

p (2 tailed)* 0.7500 0.0000 0.0000 0.0672 0.0000 0.0012 0.0477 0.0010 0.0814 0.0000 0.0000

Rain 870 2664 1173 1578 1496 1392 1333 1354 1405 1325 1671

Dry 1029 1068 2041 1785 1845 1075 1229 1029 1430 1384 1156

Rain 804897 3739879 1612162 2193928 2078909 1330995 1345419 1216037 1623964 1433380 1810166

Dry 1006760 2171763 4081463 3587772 3716402 1555009 1881652 1453169 2407417 2267180 1893115

Mann Whitney U 376622 102168 667537 1227183 1112164 508828 708906 4555906 955218 847477 550774

Z -6.331 -46.406 -25.417 -6.090 -10.203 -10.961 -3.512 -11.417 -0.823 -1.930 -16.801

p (2 tailed)* 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0004 0.0000 0.4104 0.0482 0.0000

*Bold values significant at the .05 level

All Aquatic 

Preserves

San 

Carlos 

Bay

Matlacha 

Pass

Sum of

Ranks

Estero 

Bay

Sum of

Ranks

Sum of

Ranks

Pine 

Island 

Sound

Mean 

Rank

Sum of

Ranks

Mean 

Rank

Mean 

Rank

Sum of

Ranks

Mean 

Rank

Mean 

Rank
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXX 

Table B.3: Aquatic Preserve non parametric t-test (Mann Whitney) post hoc comparisons 

Mann-Whitney U Z p( 2-tailed) *

Upper Charlotte Lower Charlotte Upper Charlotte Lower Charlotte

Secchi 217.15 373.26 85558.00 39192.00 7743 -9.886 0.0000

Temp 449.09 470.40 295055.00 118540.00 78902 -1.097 0.2727

DO 440.40 471.63 286260.00 116493.00 74685 -1.613 0.1067

pH 353.83 716.49 232465.00 178406.00 16312 -18.764 0.0000

Salinity 369.23 657.76 239629.00 163124.00 28704 -14.918 0.0000

TN 388.66 278.04 196273.00 57555.00 36027 -5.063 0.0000

TP 450.00 185.95 239398.50 39979.50 16760 -15.147 0.0000

Chl a 364.61 281.82 175740.00 55800.00 36099 -4.869 0.0000

Coliform 478.38 241.97 280810.50 56620.50 29126 -12.920 0.0000

Turbidity 423.91 311.77 235692.50 70460.50 44810 -6.294 0.0000

Color 452.82 242.11 252219.50 54716.50 29066 -11.827 0.0000

Upper Charlotte Gasp/Cape Haze Upper Charlotte Gasp/Cape Haze

Secchi 213.24 365.38 84017.00 31423.00 6202 -9.243 0.0000

Temp 416.28 454.84 273495.50 87329.50 57343 -1.920 0.0549

DO 438.86 352.56 285260.50 66280.50 48515 -4.307 0.0000

pH 350.65 681.16 230380.00 132146.00 14227 -16.595 0.0000

Salinity 343.60 682.63 222995.50 131065.50 12071 -16.989 0.0000

TN 338.60 269.43 170991.50 37989.50 27979 -3.891 0.0001

TP 400.82 131.10 213238.00 19665.00 8340 -14.812 0.0000

Chl a 340.54 225.77 164142.00 32736.00 22151 -6.690 0.0000

Coliform 413.56 256.73 242758.00 43388.00 29023 -8.235 0.0000

Turbidity 358.61 362.56 199386.00 58735.00 44540 -0.214 0.8309

Color 413.17 177.19 230134.50 28705.50 15503 -12.745 0.0000

Upper Charlotte Estero Bay Upper Charlotte Estero Bay

Secchi 253.78 357.72 99989.50 63316.50 22175 -6.985 0.0000

Temp 511.21 506.39 335862.50 182808.50 117468 -0.250 0.8024

DO 536.25 443.70 348563.00 157958.00 94412 -4.832 0.0000

pH 401.34 702.87 263679.00 250926.00 47526 -15.811 0.0000

Salinity 397.71 695.82 258111.50 248409.50 47187 -15.572 0.0000

TN 435.31 309.92 219832.50 85538.50 47313 -7.425 0.0000

TP 547.60 177.49 291321.00 52714.00 8461 -21.345 0.0000

Chl a 407.83 309.16 196575.50 81309.50 46594 -5.981 0.0000

Coliform 496.08 394.62 291201.50 130619.50 75674 -5.573 0.0000

Turbidity 382.43 534.86 212629.50 170620.50 57784 -8.588 0.0000

Color 517.62 300.36 288312.00 95814.00 44774 -12.247 0.0000

Upper Charlotte San Carlos Bay Upper Charlotte San Carlos Bay

Secchi 260.86 481.66 102779.00 157502.00 24964 -14.201 0.0000

Temp 485.61 524.88 319042.50 178460.50 102890 -2.045 0.0409

DO 440.32 594.05 286206.00 198414.00 74631 -8.037 0.0000

pH 358.44 769.94 235498.00 261008.00 19345 -21.564 0.0000

Salinity 377.98 717.58 245308.00 243258.00 34383 -17.759 0.0000

TN 422.94 285.35 213583.00 71052.00 39927 -8.158 0.0000

TP 515.91 159.49 274464.00 41946.00 7230 -20.596 0.0000

Chl a 411.21 271.11 198205.00 66423.00 36288 -8.503 0.0000

Coliform 541.68 273.50 317968.00 84785.00 36580 -14.782 0.0000

Turbidity 402.51 468.98 223794.50 137880.50 68949 -3.755 0.0002

Color 512.95 261.27 285713.00 76813.00 33448 -14.219 0.0000

* Bold values significant at the .05 level

Mean Rank Sum of Ranks
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXXI 

Table B.3, cont.

Mann-Whitney U Z p( 2-tailed) *

Upper Charlotte Lower Lemon Bay Upper Charlotte Lower Lemon Bay

Secchi 248.21 422.64 97793.50 97206.50 19979 -11.693 0.0000

Temp 592.09 590.76 389002.50 310150.50 172076 -0.066 0.9470

DO 629.81 523.92 409377.50 269817.50 136948 -5.337 0.0000

pH 397.29 831.21 261022.00 432231.00 44869 -21.914 0.0000

Salinity 373.22 848.09 242218.00 439310.00 31293 -23.915 0.0000

TN 427.90 304.69 216092.00 80743.00 45498 -7.303 0.0000

TP 519.86 179.87 276564.50 49463.50 11514 -19.643 0.0000

Chl a 405.84 299.36 195616.00 76337.00 43697 -6.792 0.0000

Coliform 482.82 371.49 283415.50 112189.50 66437 -6.129 0.0000

Turbidity 431.37 417.34 239844.00 123534.00 79578 -0.792 0.4281

Color 523.53 245.35 291607.50 72623.50 28668 -15.716 0.0000

Upper Charlotte Upper Lemon Bay Upper Charlotte Upper Lemon Bay

Secchi 282.01 268.19 111111.50 43178.50 30138 -0.926 0.3540

Temp 518.54 521.16 340679.00 198562.00 124526 -0.136 0.8918

DO 590.93 374.45 384106.50 139669.50 69919 -11.282 0.0000

pH 444.59 644.55 292098.00 242997.00 75945 -10.470 0.0000

Salinity 455.78 611.77 295798.00 230027.00 84873 -8.131 0.0000

TN 362.14 363.33 182880.00 79570.00 55115 -0.071 0.9437

TP 414.60 300.93 220568.00 68612.00 42506 -6.544 0.0000

Chl a 341.89 355.49 164789.50 74296.50 48387 -0.823 0.4110

Coliform 398.92 469.10 234167.50 118212.50 61590 -3.847 0.0001

Turbidity 412.39 366.32 229289.50 87916.50 58997 -2.595 0.0090

Color 447.79 283.64 249416.50 67789.50 39110 -9.246 0.0000

Upper Charlotte Matlacha Pass Upper Charlotte Matlacha Pass

Secchi 228.32 435.39 89956.50 87949.50 12142 -13.926 0.0000

Temp 452.99 475.89 297612.50 124208.50 81460 -1.183 0.2369

DO 434.63 495.01 282511.00 124742.00 70936 -3.124 0.0018

pH 366.13 684.91 240550.50 171227.50 24398 -16.536 0.0000

Salinity 421.97 534.57 273858.50 137919.50 62934 -5.840 0.0000

TN 367.07 305.57 185370.00 59280.00 40365 -3.606 0.0000

TP 462.12 147.60 245848.50 31291.50 8714 -18.023 0.0000

Chl a 366.56 253.66 176680.50 47434.50 29857 -6.781 0.0000

Coliform 482.30 232.13 283112.50 54318.50 26824 -13.673 0.0000

Turbidity 415.66 321.92 231108.00 71145.00 46614 -5.253 0.0000

Color 434.11 277.06 241800.50 61230.50 36700 -8.802 0.0000

Upper Charlotte Pine Island Sound Upper Charlotte Pine Island Sound

Secchi 238.88 380.37 94118.50 63522.50 16304 -9.481 0.0000

Temp 528.95 529.08 347520.50 211632.50 131368 -0.007 0.9946

DO 477.70 594.12 310506.50 232896.50 98932 -6.051 0.0000

pH 363.09 793.77 238550.50 307984.50 22398 -22.404 0.0000

Salinity 355.99 798.59 231039.00 318637.00 20114 -22.986 0.0000

TN 453.90 331.67 229219.00 102486.00 54591 -7.198 0.0000

TP 576.38 197.93 306636.00 65317.00 10702 -21.698 0.0000

Chl a 415.07 350.76 200064.00 104526.00 59975 -3.874 0.0001

Coliform 608.50 296.98 357191.00 113744.00 40208 -17.027 0.0000

Turbidity 466.47 456.50 259359.50 167990.50 100095 -0.556 0.5779

Color 584.82 280.37 325746.00 103455.00 35190 -16.983 0.0000

* Bold values significant at the .05 level

Mean Rank Sum of Ranks
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXXII 

Table B.3, cont.

Mann-Whitney U Z p( 2-tailed) *

Lower Charlotte Gasp/Cape Haze Lower Charlotte Gasp/Cape Haze

Secchi 101.03 89.85 10608.50 7727.50 3987 -1.392 0.1638

Temp 218.28 228.04 55006.00 43784.00 23128 -0.796 0.4262

DO 244.67 182.95 60434.50 34395.50 16630 -5.074 0.0000

pH 225.52 217.48 56154.50 42191.50 23277 -0.671 0.5021

Salinity 186.68 264.18 46297.00 50723.00 15421 -6.341 0.0000

TN 166.05 186.90 34372.50 26353.50 12845 -1.898 0.0576

TP 201.89 155.93 43406.00 23389.00 12064 -4.100 0.0000

Chl a 181.12 159.54 35862.50 23133.50 12549 -1.992 0.0460

Coliform 185.96 224.21 43514.50 37891.50 16020 -3.296 0.0010

Turbidity 170.54 227.92 38542.50 36923.50 12892 -4.972 0.0000

Color 205.96 178.51 46547.50 28918.50 15716 -2.390 0.0168

Lower Charlotte Estero Bay Lower Charlotte Estero Bay

Secchi 174.68 121.82 18341.50 21561.50 5809 -5.273 0.0000

Temp 317.77 299.48 80078.00 108113.00 42772 -1.260 0.2077

DO 349.59 268.98 86349.00 95757.00 32211 -5.589 0.0000

pH 359.57 264.39 89533.50 94387.50 30485 -6.704 0.0000

Salinity 292.11 310.57 72443.00 110872.00 41567 -1.277 0.2014

TN 242.28 241.79 50151.50 66734.50 28509 -0.038 0.9700

TP 332.51 201.48 71489.00 59839.00 15586 -9.906 0.0000

Chl a 232.38 229.96 46010.50 60480.50 25765 -0.192 0.8470

Coliform 225.26 323.82 52712.00 107183.00 25217 -7.119 0.0000

Turbidity 187.19 333.80 42304.00 106481.00 16653 -10.709 0.0000

Color 263.56 279.69 59563.50 89221.50 33913 -1.183 0.2370

Lower Charlotte San Carlos Bay Lower Charlotte San Carlos Bay

Secchi 237.51 209.75 24939.00 68589.00 14961 -1.986 0.0471

Temp 290.81 300.72 73283.50 102244.50 41406 -0.698 0.4852

DO 250.80 320.73 61948.00 107123.00 31320 -4.966 0.0000

pH 302.98 288.27 75441.00 97725.00 40095 -1.064 0.2875

Salinity 276.46 306.83 68562.00 104016.00 37686 -2.143 0.0321

TN 234.15 223.80 48470.00 55726.00 24601 -0.836 0.4034

TP 305.43 185.60 65668.00 48813.00 14097 -9.450 0.0000

Chl a 238.96 208.29 47314.50 51031.50 20897 -2.507 0.0120

Coliform 274.63 270.89 64264.00 83976.00 35771 -0.281 0.7790

Turbidity 202.60 305.01 45788.00 89672.00 20137 -7.706 0.0000

Color 276.51 248.19 62492.00 72968.00 29603 -2.138 0.0325

Lower Charlotte Lower Lemon Bay Lower Charlotte Lower Lemon Bay

Secchi 196.10 155.17 20590.50 35689.50 9125 -3.598 0.0003

Temp 401.55 382.98 101190.00 201063.00 62988 -1.081 0.2795

DO 448.60 349.32 110804.50 179898.50 47029 -5.829 0.0000

pH 396.69 379.40 98776.00 197289.00 61829 -1.029 0.3037

Salinity 283.11 431.56 70212.50 223548.50 39337 -8.689 0.0000

TN 236.67 236.37 48990.00 62638.00 27393 -0.023 0.9810

TP 290.11 210.62 62374.50 57920.50 19971 -6.175 0.0000

Chl a 232.44 222.77 46024.00 56807.00 24167 -0.780 0.4350

Coliform 221.27 305.10 51777.00 92139.00 24282 -6.267 0.0000

Turbidity 223.89 290.22 50598.50 85904.50 24948 -4.980 0.0000

Color 293.05 237.41 66230.00 70273.00 26317 -4.194 0.0000

* Bold values significant at the .05 level

Mean Rank Sum of Ranks
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXXIII 

Table B.3, cont.

Mann-Whitney U Z p( 2-tailed) *

Lower Charlotte Upper Lemon Bay Lower Charlotte Upper Lemon Bay

Secchi 189.20 97.17 19866.00 15645.00 2604 -9.580 0.0000

Temp 325.19 311.58 81949.00 118712.00 45941 -0.918 0.3586

DO 401.90 249.97 99269.50 93240.50 23490 -10.341 0.0000

pH 402.29 254.86 100169.00 96082.00 24829 -10.076 0.0000

Salinity 366.26 277.04 90831.50 104168.50 33293 -6.050 0.0000

TN 176.89 248.10 36616.50 54334.50 15089 -5.967 0.0000

TP 153.36 286.73 32971.50 65374.50 9752 -10.967 0.0000

Chl a 174.18 232.25 34487.50 48540.50 14787 -4.978 0.0000

Coliform 163.36 317.91 38226.50 80114.50 10732 -12.170 0.0000

Turbidity 208.36 257.17 47090.00 61721.00 21439 -3.911 0.0001

Color 216.26 248.83 48874.50 59470.50 23224 -2.621 0.0088

Lower Charlotte Matlacha Pass Lower Charlotte Matlacha Pass

Secchi 155.13 153.41 16288.50 30989.50 10487 -0.161 0.8722

Temp 256.46 257.52 64627.50 67213.50 32750 -0.081 0.9351

DO 242.29 257.56 59845.50 64904.50 29218 -1.183 0.2368

pH 287.42 212.73 71567.50 53182.50 21808 -5.901 0.0000

Salinity 316.03 193.39 78376.50 49894.50 16484 -9.433 0.0000

TN 185.31 217.74 38358.50 42242.50 16831 -2.801 0.0051

TP 246.77 180.77 53054.50 38323.50 15746 -5.533 0.0000

Chl a 201.83 183.66 39961.50 34343.50 16766 -1.602 0.1090

Coliform 235.80 233.20 55176.50 54569.50 27075 -0.212 0.8324

Turbidity 216.77 231.39 48990.50 51137.50 23340 -1.197 0.2314

Color 204.12 244.33 46130.50 53997.50 20480 -3.301 0.0010

Lower Charlotte Pine Island Sound Lower Charlotte Pine Island Sound

Secchi 154.91 124.92 16266.00 20862.00 6834 -3.067 0.0022

Temp 335.70 320.71 84596.00 128282.00 48082 -0.991 0.3215

DO 286.92 340.84 70869.50 133610.50 40242 -3.596 0.0003

pH 269.15 350.99 67018.00 136185.00 35893 -5.570 0.0000

Salinity 245.09 373.04 60783.50 148844.50 29908 -8.466 0.0000

TN 258.55 258.47 53520.00 79866.00 31971 -0.006 0.9950

TP 355.97 218.94 76533.50 72251.50 17637 -9.941 0.0000

Chl a 236.28 256.62 46783.50 76472.50 27083 -1.548 0.1220

Coliform 338.11 291.21 79118.50 111534.50 37999 -3.292 0.0010

Turbidity 257.88 321.83 58281.50 118433.50 32631 -4.410 0.0000

Color 334.33 275.75 75558.00 101752.00 33487 -4.053 0.0001

Gasp/Cape Haze Estero Bay Gasp/Cape Haze Estero Bay

Secchi 162.29 117.28 13957.00 20759.00 5006 -4.513 0.0000

Temp 295.41 267.21 56718.50 96462.50 31122 -1.979 0.0478

DO 267.70 275.04 50327.50 97912.50 32562 -0.518 0.6046

pH 326.87 248.36 63412.00 88664.00 24761 -5.645 0.0000

Salinity 321.34 250.08 61697.00 89278.00 25375 -5.020 0.0000

TN 224.34 201.16 31631.50 55521.50 17296 -1.857 0.0630

TP 261.84 204.89 39276.00 60852.00 16599 -4.409 0.0000

Chl a 187.51 213.87 27188.50 56247.50 16604 -2.162 0.0310

Coliform 221.63 265.24 37455.00 87795.00 23090 -3.206 0.0013

Turbidity 186.62 268.61 30233.00 85688.00 17030 -6.115 0.0000

Color 208.59 257.46 33791.50 82129.50 20589 -3.661 0.0003

* Bold values significant at the .05 level

Mean Rank Sum of Ranks
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXXIV 

Table B.3, cont.

Mann-Whitney U Z p( 2-tailed) *

Gasp/Cape Haze San Carlos Bay Gasp/Cape Haze San Carlos Bay

Secchi 208.41 206.63 17923.00 67568.00 13940 -0.123 0.9020

Temp 268.25 265.51 51503.50 90274.50 32305 -0.197 0.8436

DO 171.55 312.13 32251.50 104251.50 14486 -10.226 0.0000

pH 268.92 265.90 52170.00 90141.00 32511 -0.224 0.8226

Salinity 309.43 241.40 59410.00 81836.00 24206 -4.909 0.0000

TN 216.04 183.87 30461.50 45783.50 14659 -2.708 0.0068

TP 238.11 189.26 35716.50 49774.50 15059 -4.009 0.0001

Chl a 196.60 194.85 28506.50 47738.50 17604 -0.148 0.8820

Coliform 272.27 222.41 46013.50 68946.50 20742 -3.822 0.0001

Turbidity 206.77 240.47 33497.00 70699.00 20294 -2.614 0.0089

Color 226.18 229.78 36641.00 67555.00 23438 -0.281 0.7791

Gasp/Cape Haze Lower Lemon Bay Gasp/Cape Haze Lower Lemon Bay

Secchi 180.35 150.33 15510.00 34576.00 8011 -2.609 0.0091

Temp 382.48 350.41 73436.50 183966.50 45892 -1.839 0.0659

DO 347.16 353.77 65265.50 182190.50 47500 -0.382 0.7024

pH 357.80 357.39 69414.00 185841.00 50381 -0.025 0.9804

Salinity 343.95 359.78 66037.50 186367.50 47510 -0.914 0.3607

TN 219.19 195.15 30906.00 51715.00 16470 -1.966 0.0489

TP 219.90 209.24 32985.00 57540.00 19590 -0.857 0.3917

Chl a 188.80 207.15 27376.00 52824.00 16791 -1.527 0.1270

Coliform 214.76 247.88 36295.00 74861.00 21930 -2.545 0.0109

Turbidity 235.94 225.97 38223.00 66888.00 22932 -0.771 0.4407

Color 244.15 221.48 39552.50 65558.50 21603 -1.763 0.0778

Gasp/Cape Haze Upper Lemon Bay Gasp/Cape Haze Upper Lemon Bay

Secchi 185.56 91.12 15958.00 14670.00 1629 -9.945 0.0000

Temp 303.21 278.83 58217.00 106234.00 33463 -1.666 0.0956

DO 328.97 256.82 61847.00 95794.00 26043 -4.978 0.0000

pH 369.26 243.16 71635.50 91670.50 20418 -8.740 0.0000

Salinity 387.72 231.79 74441.50 87154.50 16279 -10.712 0.0000

TN 153.65 197.79 21664.50 43315.50 11654 -3.928 0.0000

TP 108.84 242.57 16326.00 55305.00 5001 -11.648 0.0000

Chl a 134.12 207.59 19448.00 43387.00 8863 -6.643 0.0000

Coliform 147.47 253.60 24923.00 63908.00 10558 -8.785 0.0000

Turbidity 216.42 191.43 35059.50 45943.50 17024 -2.115 0.0340

Color 167.73 223.55 27171.50 53429.50 13969 -4.756 0.0000

Gasp/Cape Haze Matlacha Pass Gasp/Cape Haze Matlacha Pass

Secchi 127.14 151.89 10934.00 30682.00 7193 -2.312 0.0208

Temp 232.07 223.27 44558.00 58273.00 24082 -0.709 0.4786

DO 176.68 253.19 33216.00 63804.00 15450 -6.245 0.0000

pH 256.55 196.08 49770.50 49019.50 17645 -5.047 0.0000

Salinity 314.87 158.99 60454.50 41020.50 7610 -12.576 0.0000

TN 162.51 171.99 22914.50 33365.50 12904 -0.884 0.3768

TP 184.67 179.26 27700.50 38002.50 15425 -0.486 0.6272

Chl a 164.21 168.27 23811.00 31467.00 13226 -0.382 0.7020

Coliform 226.40 184.38 38261.50 43144.50 15650 -3.620 0.0003

Turbidity 219.40 171.92 35542.50 37993.50 13463 -4.148 0.0000

Color 155.55 218.72 25198.50 48337.50 11996 -5.542 0.0000

* Bold values significant at the .05 level

Mean Rank Sum of Ranks
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXXV 

Table B.3, cont.

Mann-Whitney U Z p( 2-tailed) *

Gasp/Cape Haze Pine Island Sound Gasp/Cape Haze Pine Island Sound

Secchi 140.04 120.28 12043.50 20087.50 6060 -2.039 0.0415

Temp 314.42 287.90 60368.00 115160.00 34960 -1.769 0.0769

DO 208.37 329.89 39174.00 129316.00 21408 -8.176 0.0000

pH 231.70 321.40 44949.00 124704.00 26034 -6.168 0.0000

Salinity 291.07 298.37 55884.50 119051.50 37357 -0.487 0.6259

TN 243.95 217.08 34397.00 67078.00 19183 -2.033 0.0418

TP 284.26 220.61 42639.00 72801.00 18186 -4.668 0.0000

Chl a 190.66 237.25 27645.50 70700.50 17061 -3.595 0.0000

Coliform 338.84 248.99 57264.00 95364.00 21828 -6.291 0.0000

Turbidity 271.20 262.99 43934.00 96781.00 28885 -0.568 0.5698

Color 279.58 260.04 45292.50 95953.50 27689 -1.361 0.1737

Estero Bay San Carlos Bay Estero Bay San Carlos Bay

Secchi 200.51 280.64 35489.50 91770.50 19737 -5.909 0.0000

Temp 336.15 366.77 121349.50 124701.50 56009 -2.003 0.0451

DO 255.67 441.25 91017.50 147377.50 27472 -12.226 0.0000

pH 297.26 402.46 106121.00 136435.00 42218 -7.070 0.0000

Salinity 343.73 353.53 122711.00 119845.00 58808 -0.643 0.5205

TN 268.86 353.53 122711.00 119845.00 32744 -0.932 0.3510

TP 278.29 283.00 82652.00 74428.00 38399 -0.344 0.7306

Chl a 272.26 235.43 71604.50 57681.50 27547 -2.826 0.0050

Coliform 377.67 260.50 125007.50 80753.50 32549 -8.073 0.0000

Turbidity 336.94 274.51 107484.50 80706.50 37342 -4.361 0.0000

Color 330.46 281.55 105416.00 82775.00 39410 -3.427 0.0006

Estero Bay Lower Lemon Bay Estero Bay Lower Lemon Bay

Secchi 181.93 220.98 32202.00 50826.00 16449 -3.331 0.0009

Temp 441.54 444.85 159395.50 233545.50 94055 -0.189 0.8497

DO 436.30 435.79 155323.50 224432.50 91563 -0.029 0.9765

pH 371.28 485.49 132546.50 252456.50 68644 -6.671 0.0000

Salinity 360.97 491.09 128867.00 254383.00 64964 -7.485 0.0000

TN 271.19 270.80 74848.50 71762.50 36518 -0.029 0.9770

TP 255.60 319.88 75912.00 87966.00 31659 -4.656 0.0000

Chl a 265.01 253.82 69698.00 64723.00 32083 -0.851 0.3950

Coliform 321.70 311.85 106482.00 94179.00 48426 -0.679 0.4972

Turbidity 362.08 249.72 115504.00 73916.00 29960 -7.837 0.0000

Color 346.24 266.79 110449.00 78971.00 35015 -5.560 0.0000

Estero Bay Upper Lemon Bay Estero Bay Upper Lemon Bay

Secchi 207.22 128.03 36677.50 20613.50 7573 -7.476 0.0000

Temp 368.60 374.25 133063.00 142590.00 67722 -0.360 0.7190

DO 418.85 313.61 149110.00 116975.00 47224 -6.746 0.0000

pH 405.11 331.89 144624.00 125121.00 53868 -4.732 0.0000

Salinity 423.90 312.97 151333.50 117677.50 46802 -7.090 0.0000

TN 209.64 296.34 57861.00 64899.00 19635 -6.698 0.0000

TP 167.00 388.06 49598.00 88477.00 5345 -16.561 0.0000

Chl a 204.08 277.29 53673.50 57954.50 18958 -5.793 0.0000

Coliform 249.48 347.85 82579.00 87657.00 27633 -6.994 0.0000

Turbidity 332.86 209.74 106183.50 50336.50 21417 -8.932 0.0000

Color 269.67 292.62 86025.00 69936.00 34985 -1.670 0.0950

* Bold values significant at the .05 level

Mean Rank Sum of Ranks
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXXVI 

Table B.3, cont.

Mann-Whitney U Z p( 2-tailed) *

Estero Bay Matlacha Pass Estero Bay Matlacha Pass

Secchi 143.58 230.67 25414.00 46596.00 9661 -7.736 0.0000

Temp 303.53 322.53 109573.00 84180.00 44232 -1.304 0.1924

DO 262.43 363.93 93424.50 91711.50 29879 -7.021 0.0000

pH 297.17 313.75 106090.50 78437.50 42188 -1.172 0.2414

Salinity 365.64 228.25 130532.50 58887.50 25477 -9.463 0.0000

TN 218.95 259.05 60430.00 50255.00 22204 -3.151 0.0020

TP 228.21 292.53 67778.00 62017.00 23525 -4.874 0.0000

Chl a 235.74 211.10 62000.00 39475.00 21897 -1.981 0.0480

Coliform 326.28 221.77 108000.00 51895.00 24400 -7.550 0.0000

Turbidity 327.55 188.15 104488.50 41581.50 17051 -10.209 0.0000

Color 257.15 289.77 82031.50 64038.50 30992 -2.396 0.0166

Estero Bay Pine Island Sound Estero Bay Pine Island Sound

Secchi 157.98 187.89 27963.00 31377.00 12210 -2.795 0.0052

Temp 379.23 382.60 136901.50 153039.50 71561 -0.212 0.8325

DO 294.59 447.07 104875.00 175251.00 41329 -9.641 0.0000

pH 273.49 464.56 97636.00 180249.00 33733 -12.243 0.0000

Salinity 320.46 430.43 114402.50 171743.50 50500 -6.913 0.0000

TN 292.63 293.33 80767.00 90638.00 42541 -0.049 0.9610

TP 319.31 309.22 94835.00 102043.00 47428 -0.698 0.4853

Chl a 266.54 293.33 70100.00 87541.00 35384 -1.985 0.0470

Coliform 445.45 281.49 147445.00 107810.00 34274 -10.775 0.0000

Turbidity 402.48 293.31 128391.00 107937.00 40041 -7.191 0.0000

Color 390.11 305.07 124443.50 112572.50 44308 -5.619 0.0000

San Carlos Bay Lower Lemon Bay San Carlos Bay Lower Lemon Bay

Secchi 297.97 252.03 97437.00 57966.00 31401 -3.326 0.0009

Temp 453.21 419.91 154091.50 220453.50 82379 -1.917 0.0552

DO 557.17 339.28 186094.00 174731.00 41861 -12.651 0.0000

pH 427.73 431.48 145000.50 224369.50 87371 -0.221 0.8249

Salinity 352.18 479.27 119389.00 248264.00 61759 -7.350 0.0000

TN 251.70 262.95 62673.00 69682.00 31548 -0.858 0.3910

TP 240.28 297.45 63192.50 81798.50 28477 -4.273 0.0000

Chl a 237.92 262.58 58291.50 66958.50 28157 -1.908 0.0560

Coliform 256.70 357.62 79577.50 108000.50 31373 -7.128 0.0000

Turbidity 322.37 268.81 94777.50 79567.50 35612 -3.817 0.0001

Color 310.10 281.00 91170.00 83175.00 39219 -2.083 0.0373

San Carlos Bay Upper Lemon Bay San Carlos Bay Upper Lemon Bay

Secchi 302.78 126.14 99007.50 20308.50 7268 -13.043 0.0000

Temp 374.25 349.18 127245.00 133036.00 60265 -1.615 0.1062

DO 482.99 238.50 161317.00 88961.00 19210 -15.894 0.0000

pH 446.46 279.41 151349.50 105336.50 34084 -10.937 0.0000

Salinity 425.92 296.76 144388.50 111581.50 40706 -8.350 0.0000

TN 191.33 283.59 47640.50 62105.50 16516 -7.364 0.0000

TP 149.80 356.97 39397.50 81388.50 4682 -16.147 0.0000

Chl a 182.61 280.12 44739.50 58545.50 14605 -7.894 0.0000

Coliform 199.25 382.68 61768.50 96434.50 13564 -13.390 0.0000

Turbidity 299.36 228.47 88012.50 54832.50 25913 -5.282 0.0000

Color 238.70 301.81 70178.00 72133.00 26813 -4.719 0.0000

* Bold values significant at the .05 level

Mean Rank Sum of Ranks
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXXVII 

Table B.3, cont.

Mann-Whitney U Z p( 2-tailed) *

San Carlos Bay Matlacha Pass San Carlos Bay Matlacha Pass

Secchi 248.10 292.36 81128.50 59056.50 27501 -3.241 0.0012

Temp 304.84 295.99 103647.00 77254.00 43063 -0.620 0.5351

DO 316.36 263.20 105664.50 66326.50 34449 -3.765 0.0002

pH 331.18 245.94 112269.50 61485.50 30111 -6.181 0.0000

Salinity 368.45 207.74 124905.50 53597.50 20187 -11.278 0.0000

TN 201.06 248.88 50063.50 48282.50 18939 -3.901 0.0000

TP 212.69 269.40 55938.00 57112.00 21222 -4.486 0.0000

Chl a 214.12 219.62 52459.00 41069.00 22324 -0.454 0.6500

Coliform 272.12 273.00 84357.00 63883.00 36152 -0.066 0.9471

Turbidity 298.15 204.58 87657.00 45213.00 20682 -7.064 0.0000

Color 227.55 298.51 66899.00 65971.00 23534 -5.371 0.0000

San Carlos Bay Pine Island Sound San Carlos Bay Pine Island Sound

Secchi 258.76 225.46 84613.00 37652.00 23624 -2.457 0.0140

Temp 386.06 357.28 131259.00 142911.00 62711 -1.828 0.0676

DO 368.54 359.20 123093.50 140807.50 63780 -0.598 0.5496

pH 297.06 422.48 100705.00 163923.00 43075 -8.163 0.0000

Salinity 311.71 418.60 105670.50 167020.50 48041 -6.788 0.0000

TN 272.26 285.33 67792.50 88168.50 36668 -0.952 0.3410

TP 305.88 289.92 80447.00 95674.00 41059 -1.130 0.2586

Chl a 238.47 299.57 58425.50 89270.50 28291 -4.516 0.0000

Coliform 374.00 325.15 115938.50 124532.50 50997 -3.310 0.0009

Turbidity 358.41 310.00 105374.00 114079.00 46183 -3.237 0.0012

Color 346.70 320.28 101931.00 118185.00 49920 -1.773 0.0762

Lower Lemon Bay Upper Lemon Bay Lower Lemon Bay Upper Lemon Bay

Secchi 253.07 114.47 58206.50 18429.50 5389 -11.979 0.0000

Temp 452.16 455.34 237386.00 173485.00 99311 -0.181 0.8566

DO 493.43 376.95 254115.50 140600.50 70850 -6.681 0.0000

pH 526.66 341.89 273861.00 128892.00 57639 -10.655 0.0000

Salinity 555.24 299.07 287615.50 112449.50 41574 -14.644 0.0000

TN 204.48 288.50 54188.50 63181.50 18944 -6.578 0.0000

TP 163.23 359.07 44889.00 81867.00 6939 -15.052 0.0000

Chl a 197.06 275.73 50251.50 57628.50 17612 -6.288 0.0000

Coliform 232.07 331.95 70084.50 83650.50 24332 -7.323 0.0000

Turbidity 277.21 257.76 82054.00 61862.00 32942 -1.446 0.1480

Color 228.09 317.43 67515.00 75865.00 23559 -6.669 0.0000

Lower Lemon Bay Matlacha Pass Lower Lemon Bay Matlacha Pass

Secchi 182.15 255.61 41895.00 51633.00 15330 -6.116 0.0000

Temp 386.89 406.79 203119.00 106172.00 65044 -1.159 0.2466

DO 343.65 466.46 176980.00 117548.00 44110 -7.212 0.0000

pH 415.67 322.74 216149.00 80686.00 49311 -5.524 0.0000

Salinity 480.00 204.78 248642.50 52833.50 19423 -16.114 0.0000

TN 213.60 252.40 56603.50 48966.50 21359 -3.096 0.0020

TP 241.33 247.46 66366.00 52462.00 28416 -0.477 0.6330

Chl a 227.72 213.02 58069.00 39834.00 22256 -1.196 0.2320

Coliform 307.35 218.36 92819.50 51096.50 23602 -6.652 0.0000

Turbidity 281.64 228.67 83366.00 50537.00 26006 -3.989 0.0001

Color 218.20 313.64 64588.50 69314.50 20633 -7.210 0.0000

* Bold values significant at the .05 level

Mean Rank Sum of Ranks
Appendix B CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXXVIII 

Table B.3, cont.

Mann-Whitney U Z p( 2-tailed) *

Lower Lemon Bay Pine Island Sound Lower Lemon Bay Pine Island Sound

Secchi 199.59 198.19 45905.50 33097.50 19070 -0.120 0.9041

Temp 462.79 463.27 242966.50 185308.50 104892 -0.027 0.9785

DO 376.46 555.88 193874.50 217903.50 61005 -10.220 0.0000

pH 398.19 529.97 207059.00 205627.00 71599 -7.605 0.0000

Salinity 463.20 453.54 239940.00 180963.00 101163 -0.548 0.5838

TN 286.90 288.01 76028.50 88996.50 40784 -0.080 0.9360

TP 342.29 270.25 94131.00 89184.00 34569 -5.056 0.0000

Chl a 258.06 293.20 65806.50 87374.50 33167 -2.578 0.0100

Coliform 424.99 278.35 128347.00 106608.00 33072 -9.821 0.0000

Turbidity 332.44 332.54 98403.50 122376.50 54448 -0.007 0.9946

Color 328.24 336.82 97160.00 124285.00 53204 -0.575 0.5651

Upper Lemon Bay Matlacha Pass Upper Lemon Bay Matlacha Pass

Secchi 102.60 245.28 16518.50 49547.50 3478 -12.909 0.0000

Temp 315.88 329.71 120349.50 86053.50 47579 -0.929 0.3528

DO 244.71 414.09 91275.00 104350.00 21524 -11.506 0.0000

pH 279.89 365.44 105518.50 91359.50 34266 -5.861 0.0000

Salinity 331.26 297.45 124552.00 76743.00 43332 -2.283 0.0224

TN 225.99 185.56 49491.50 35999.50 17085 -3.435 0.0010

TP 303.70 131.02 69244.50 27775.50 5198 -14.242 0.0000

Chl a 233.98 158.85 48901.50 29704.50 12127 -6.522 0.0000

Coliform 321.26 159.75 80958.50 37382.50 9888 -12.719 0.0000

Turbidity 248.55 211.94 59651.50 46839.50 22309 -2.948 0.0030

Color 226.44 234.89 54119.50 51910.50 25440 -0.683 0.4945

Upper Lemon Bay Pine Island Sound Upper Lemon Bay Pine Island Sound

Secchi 112.97 214.18 18188.00 35768.00 5147 -9.708 0.0000

Temp 392.10 389.95 149391.50 155979.50 75780 -0.134 0.8937

DO 273.67 487.03 102080.00 190915.00 32329 -13.350 0.0000

pH 265.99 496.70 100277.00 192718.00 29024 -14.536 0.0000

Salinity 272.15 497.17 102328.00 198372.00 31452 -13.986 0.0000

TN 314.49 229.07 68873.00 70783.00 22888 -6.339 0.0000

TP 414.78 186.03 94570.00 61391.00 6776 -16.486 0.0000

Chl a 284.80 232.40 59523.00 69255.00 24704 -3.965 0.0000

Coliform 450.93 230.54 113635.00 88295.00 14759 -15.028 0.0000

Turbidity 293.55 311.64 70453.00 114683.00 41533 -1.241 0.2150

Color 364.14 265.87 87030.50 98105.50 29841 -6.766 0.0000

Matlacha Pass Pine Island Sound Matlacha Pass Pine Island Sound

Secchi 208.09 157.07 42034.50 26230.50 12203 -4.582 0.0000

Temp 341.02 324.46 89005.50 129785.50 49586 -1.091 0.2752

DO 300.26 336.80 75664.50 132025.50 43787 -2.433 0.0150

pH 216.76 385.70 54189.00 149652.00 22814 -11.428 0.0000

Salinity 180.99 424.71 46694.50 169458.50 13284 -16.074 0.0000

TN 276.40 236.68 53621.50 73134.50 25240 -2.984 0.0029

TP 315.26 243.39 66834.50 80318.50 25704 -5.224 0.0000

Chl a 216.23 259.80 40435.00 77420.00 22857 -3.333 0.0010

Coliform 337.23 291.75 78911.00 111742.00 38206 -3.191 0.0014

Turbidity 264.02 313.60 58349.50 115405.50 33819 -3.424 0.0006

Color 362.64 255.29 80144.00 94201.00 25936 -7.434 0.0000

Bold values significant at the .05 level

Mean Rank Sum of Ranks
Appendix C CHEVWQMN Repot 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XXXIX 

Appendix C: Comparison of Results to Numerical Water 

Quality Criteria 

 Page 

Table C.1: Site exceedances of dissolved oxygen under 4 mg/L per site per Florida 

Surface Water Regulations __________________________________ XL 

Table C.2: Site exceedances of dissolved oxygen under 5 mg/L per site per Florida 

Surface Water Regulations __________________________________ XLI 

Table C.3: Exceedances of 11 μg/L chlorophyll a per Florida Impaired Waters Rule for 

each estuary region _______________________________________ XLII 

Table C.4: Site exceedances of chlorophyll a under 11 μg/L per site per Florida Surface 

Water Regulations ________________________________________ XLIII 

Table C.5: Site specific exceedances of fecal coliform bacteria per Florida Surface 

Water Regulations ________________________________________XLIV 
Appendix C CHEVWQMN Repot 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XL 

Table C.1: Site exceedances of dissolved oxygen under 4 mg/L per site per Florida Surface Water Regulations

* Under Total % Under Total % Under Total %

PIJIM1 28 32 88 16 20 80 12 12 100

LBV001 63 85 74 27 49 55 36 36 100

LBV006 45 63 71 22 40 55 23 23 100

GSV005 47 67 70 24 43 56 23 24 96

LBGOT2 40 67 60 17 42 40 23 25 92

GSV004 10 17 59 3 9 33 7 8 88

LBANG1 38 75 51 13 45 29 25 30 83

LBV003 42 83 51 12 50 24 30 33 91

EBERS2 25 51 49 7 30 23 18 21 86

GSV001 41 85 48 16 50 32 25 35 71

CHV008 38 90 42 6 54 11 32 36 89

LBFOR1 19 53 36 4 28 14 15 25 60

LBOYS1 26 75 35 6 44 14 20 31 65

EBV005 31 90 34 9 53 17 22 37 59

CHV003 22 64 34 3 36 8 19 28 68

EBV003 19 61 31 3 32 9 16 29 55

PIV007 18 61 30 7 33 21 11 28 39

LBV002 24 85 28 6 49 12 18 36 50

CHV009 22 83 27 5 48 10 17 35 49

MPV002 23 91 25 4 54 7 19 37 51

CHV013 13 52 25 0 30 0 13 22 59

CHV007 23 93 25 2 54 4 21 39 54

CHV010 20 86 23 5 50 10 15 36 42

LBV004 19 85 22 5 51 10 14 34 41

CHV005 8 42 19 26 0 8 16 50

EBV004 15 86 17 1 51 2 14 35 40

EBV007 7 46 15 2 27 7 5 19 26

GSV003 3 23 13 3 15 20 0 8 0

GSV002 9 73 12 6 46 13 3 27 11

CHV001 10 84 12 1 52 2 9 32 28

CHV006 10 89 11 1 54 2 9 35 26

LBV005 7 72 10 2 43 5 5 29 17

MPV001 7 84 8 0 51 0 7 33 21

CHV012 5 63 8 3 35 9 2 28 7

CHV004 6 86 7 0 50 0 6 36 17

PIV002 4 93 4 1 55 2 3 38 8

CHV002 2 50 4 0 31 0 2 19 11

EBV001 3 86 3 0 50 0 3 36 8

PIV001 2 63 3 0 40 0 2 23 9

MPV003 2 77 3 0 44 0 2 33 6

PIV006 2 82 2 1 48 2 1 34 3

MPV004 2 87 2 1 52 2 1 35 3

LBV007 1 72 1 1 43 2 0 29 0

SCV002 1 74 1 0 44 0 1 30 3

CHV011 0 78 0 0 43 0 0 35 0

PIV004 0 61 0 0 36 0 0 25 0

SCV001 0 87 0 0 53 0 0 34 0

EBV006 0 22 0 0 17 0 0 5 0

Total 802 3374 24% 245 2000 12% 557 1374 41%

*ranked in descending order by total % exceedances

All Dry Season Rainy Season
Appendix C CHEVWQMN Repot 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XLI 

Table C.2: Site exceedances of dissolved oxygen under 5 mg/L per site per Florida Surface Water Regulations

* Under Total % Under Total % Under Total %

PIJIM1 31 32 97 19 20 95 12 12 100

GSV004 16 17 94 9 9 100 7 8 88

LBV001 79 85 93 43 49 88 36 36 100

LBV006 56 63 89 33 40 83 23 23 100

GSV005 59 67 88 35 43 81 24 24 100

LBGOT2 57 67 85 33 42 79 24 25 96

GSV001 69 85 81 36 50 72 33 35 94

LBOYS1 58 75 77 27 44 61 31 31 100

LBV003 62 83 75 31 50 62 31 33 94

EBERS2 38 51 75 17 30 57 21 21 100

EBV003 42 61 69 16 32 50 26 29 90

LBANG1 50 75 67 20 45 44 30 30 100

CHV008 58 90 64 22 54 41 36 36 100

LBFOR1 33 53 62 11 28 39 22 25 88

PIV007 34 61 56 13 33 39 21 28 75

CHV003 35 64 55 8 36 22 27 28 96

LBV002 46 85 54 18 49 37 28 36 78

EBV004 46 86 53 17 51 33 29 35 83

EBV005 47 90 52 21 53 40 26 37 70

CHV013 27 52 52 7 30 23 20 22 91

LBV004 44 85 52 16 51 31 28 34 82

CHV010 44 86 51 18 50 36 26 36 72

CHV007 47 93 51 12 54 22 35 39 90

CHV009 41 83 49 13 48 27 28 35 80

CHV001 41 84 49 16 52 31 25 32 78

MPV002 44 91 48 17 54 31 27 37 73

EBV007 22 46 48 7 27 26 15 19 79

CHV005 18 42 43 4 26 15 14 16 88

GSV002 30 73 41 13 46 28 17 27 63

CHV004 28 86 33 7 50 14 21 36 58

EBV006 7 22 32 5 17 29 2 5 40

CHV006 28 89 31 4 54 7 24 35 69

MPV004 25 87 29 6 52 12 19 35 54

CHV012 17 63 27 5 35 14 12 28 43

LBV005 19 72 26 7 43 16 12 29 41

GSV003 6 23 26 5 15 33 1 8 13

MPV001 21 84 25 4 51 8 17 33 52

LBV007 17 72 24 7 43 16 10 29 34

MPV003 18 77 23 1 44 2 17 33 52

EBV001 19 86 22 4 50 8 15 36 42

PIV001 12 63 19 2 40 5 10 23 43

CHV002 8 50 16 2 31 6 6 19 32

PIV002 13 93 14 2 55 4 11 38 29

PIV006 7 82 9 1 48 2 6 34 18

SCV002 4 74 5 0 44 0 4 30 13

PIV004 3 61 5 0 36 0 3 25 12

SCV001 4 87 5 0 53 0 4 34 12

CHV011 3 78 4 0 43 0 3 35 9

Total 1533 3374 45% 614 2000 31% 919 1374 67%

*ranked in descending order by total % exceedances

All Dry Season Rainy Season
Appendix C CHEVWQMN Repot 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XLII 

Table C.3: Exceedances of 11 ug/L chlorophyll a per Florida Impaired Waters Rule for each estuary region

Upper 

Lemon 

Bay

Lower 

Lemon 

Bay

Upper 

Charlotte

Lower 

Charlotte

Gasparilla/

Cape Haze

Pine 

Island 

Sound

Matlacha 

Pass

San 

Carlos 

Bay

Estero 

Bay Total

All Over 60 21 125 28 10 47 18 13 22 344

Total 209 255 482 198 145 298 187 245 263 2282

% 29 8 26 14 7 16 10 5 8 15

Rain Over 36 10 54 12 6 27 13 7 5 170

Total 81 101 187 80 57 118 71 94 101 890

% 44 10 29 15 11 23 18 7 5 19

Dry Over 24 11 71 16 4 20 5 6 17 174

Total 128 154 295 118 88 180 116 151 162 1392

% 19 7 24 14 5 11 4 4 10 13

1998 Over 11 3 19 6 2 4 2 2 1 50

Total 13 14 34 15 12 12 11 15 11 137

% 85 21 56 40 17 33 18 13 9 36

1999 Over 10 4 21 4 3 6 4 3 3 58

Total 34 39 81 33 29 37 31 42 35 361

% 29 10 26 12 10 16 13 7 9 16

2000 Over 6 2 10 0 0 8 0 0 1 27

Total 28 30 67 30 22 50 30 43 39 339

% 21 7 15 0 0 16 0 0 3 8

2001 Over 5 2 71 1 6 2 0 3 27

Total 28 28 60 25 19 41 27 33 29 290

% 18 7 12 4 5 15 7 0 10 9

2003 Over 9 8 18 8 2 12 6 6 9 78

Total 30 43 70 31 12 60 30 39 53 368

% 30 19 26 26 17 20 20 15 17 21

2004 Over 5 0 20 4 0 221 3 37

Total 29 38 80 28 20 37 28 31 45 336

% 17 0 25 14 0 5 7 3 7 11

2005 Over 14 2 30 5 2 9 2 1 2 67

Total 47 63 90 36 31 61 30 42 51 451

% 30 3 33 14 6 15 7 2 4 15

Total Over 58 20 121 26 9 45 15 13 22 344

Total 207 254 478 196 144 296 184 245 263 2267

% 28 8 25 13 6 15 8 5 8 15
Appendix C CHEVWQMN Repot 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XLIII 

Table C.4: Site exceedances of chlorophyll a over 11 μg/L per site per Florida Surface Water Regulations

* Under Total % Under Total % Under Total %

LBFOR1 4 6 67 2 3 67 2 3 67

CHV005 15 32 47 9 20 45 6 12 50

CHV013 16 38 42 13 24 54 3 14 21

CHV001 25 62 40 13 37 35 12 25 48

LBV003 21 64 33 7 42 17 14 22 64

GSV005 9 28 32 6 20 30 3 8 38

CHV002 13 42 31 8 26 31 5 16 31

PIV002 19 69 28 5 42 12 14 27 52

CHV004 17 63 27 7 39 18 10 24 42

LBV002 18 66 27 6 40 15 12 26 46

PIJIM1 6 24 25 4 15 27 2 9 22

CHV009 16 66 24 10 39 26 6 27 22

LBV001 16 66 24 8 40 20 8 26 31

CHV006 14 63 22 9 40 23 5 23 22

CHV007 13 73 18 6 44 14 7 29 24

CHV003 8 45 18 4 27 15 4 18 22

PIV006 10 62 16 3 36 8 7 26 27

MPV002 9 70 13 3 43 7 6 27 22

LBV005 7 56 13 2 35 6 5 21 24

PIV007 6 47 13 4 28 14 2 19 11

LBGOT2 1 8 13 1 4 25 0 4 0

CHV012 6 49 12 2 29 7 4 20 20

EBV005 8 66 12 5 41 12 3 25 12

LBV006 6 52 12 4 33 12 2 19 11

EBERS2 4 36 11 4 23 17 0 13 0

PIV004 4 46 9 2 28 7 2 18 11

CHV010 6 68 9 2 41 5 4 27 15

CHV011 6 64 9 4 38 11 2 26 8

EBV007 3 32 9 3 20 15 0 12 0

EBV003 4 46 9 2 25 8 2 21 10

LBV004 6 70 9 3 44 7 3 26 12

MPV001 5 63 8 0 39 0 5 24 21

MPV003 4 54 7 2 34 6 2 20 10

GSV004 1 15 7 1 8 13 0 7 0

MPV004 4 64 6 1 39 3 3 25 12

SCV001 4 64 6 2 40 5 2 24 8

CHV008 3 66 5 1 40 3 2 26 8

EBV006 1 19 5 1 14 7 0 5 0

GSV003 1 20 5 0 14 0 1 6 17

EBV001 3 67 4 2 41 5 1 26 4

PIV001 2 53 4 2 34 6 0 19 0

SCV002 2 54 4 1 35 0 1 19 0

GSV002 2 57 4 2 34 6 0 23 0

GSV001 2 61 3 1 37 3 1 24 4

EBV004 2 67 3 2 42 5 0 25 0

LBANG1 0 7 0 0 3 0 0 4 0

LBOYS1 0 8 0 0 4 0 0 4 0

LBV007 0 8 0 0 4 0 0 4 0

Total 352 2326 15% 179 1428 13% 173 898 19%

*ranked in descending order by total % exceedances

All Rainy Season Dry Season
Appendix C CHEVWQMN Repot 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XLIV 

Table C.5: Site specific exceedances of fecal coliform bacteria per Florida Surface Water Regulations

# over N % # over N % # over N %

LBV001* 31 80 39% 12 80 15% 3 80 4%

LBV002 3 80 4%

LBV003 2 78 3% 1 78 1%

LBOYS1 1 8 13%

LBV004 1 79 1%

LBV006 9 63 14% 4 63 6%

CHV001 2 76 3%

CHV003 3 57 5%

CHV004 2 77 3%

CHV005 4 34 12% 1 34 3%

CHV007 1 87 1%

CHV008 5 82 6% 3 82 4%

CHV013 3 52 6% 2 52 4%

Lower Charlotte Harbor CHV011 1 74 1%

GSV001 1 72 1%

GSV004 1 16 6%

PIJIM1 2 34 6%

PIV001 1 66 2%

PIV006 1 76 1%

EBV001 1 81 1%

MPV004 1 81 1%

EBERS2 9 49 18% 4 49 8%

EBV005 4 83 5%

GSV005* 14 37 38% 8 37 22% 2 37 5%

Total 103 2839 4% 35 2839 1% 5 2839 < 1%

*greater than 10% of samples exceeding 400 cfu/100mL

Coliform > 200 cfu/100mL Coliform > 400 cfu/100mL Coliform > 800 cfu/100mL

Upper Lemon Bay

San Carlos Bay

Estero Bay

Lower Lemon Bay

Upper Charlotte Harbor

Gasparilla/Cape Haze

Pine Island Sound
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XLV 

Appendix D: Water Quality Relationships 

 Page 

Table D.1: Spearman's rho correlation for selected variables for the entire study region 

and duration _____________________________________________XLVI 

Table D.2: Spearman's rho correlation for selected variables in the rainy season for the 

entire study region _______________________________________ XLVII 

Table D.3: Spearman's rho correlation for selected variables in Upper Lemon 

 Bay__ _________________________________________________XLVIII 

Table D.4: Spearman's rho correlation for selected variables in Lower Lemon 

 Bay__ __________________________________________________XLIX 

Table D.5: Spearman's rho correlation for selected variables in Upper 

 Charlotte Harbor_____________________________________________L 

Table D.6: Spearman's rho correlation for selected variables in Lower 

 Charlotte Harbor____________________________________________ LI 

Table D.7: Spearman's rho correlation for selected variables in 

 Gasparilla/Cape Haze _______________________________________LII 

Table D.8: Spearman's rho correlation for selected variables in Pine 

 Island Sound _____________________________________________ LIII 

Table D.9: Spearman's rho correlation for selected variables in Matlacha 

 Pass ____________________________________________________ LIV 

Table D.10: Spearman's rho correlation for selected variables in San Carlos 

 Bay _____________________________________________________ LV 

Table D.11: Spearman's rho correlation for selected variables in Estero Bay _ LVI 
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XLVI 

Table D.1: Spearman's rho correlation for selected variables for the entire study region and duration

 Secchi DO Salinity TN TP ChlA Coliform Turbidity Color

Secchi Coefficient 0.300 0.344 -0.375 -0.505 -0.349 -0.340 -0.343 -0.451

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

N 1903 1858 1879 1295 1368 1270 1575 1497 1497

DO Coefficient 0.300 0.100 -0.196 -0.170 -0.177 -0.282 0.027 -0.260

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.000 0.165 0.000

N 1858 3374 3329 2334 2477 2249 2768 2652 2652

Salinity Coefficient 0.344 0.100 -0.370 -0.445 -0.233 -0.336 0.198 -0.711

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

N 1879 3329 3404 2354 2495 2270 2792 2675 2675

TN Coefficient -0.375 -0.196 -0.370 0.355 0.227 0.263 0.197 0.514

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

N 1295 2334 2354 2402 2320 1908 2366 2281 2280

TP Coefficient -0.505 -0.170 -0.445 0.355 0.281 0.341 0.095 0.484

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

N 1368 2477 2495 2320 2540 2020 2508 2406 2406

ChlA Coefficient -0.349 -0.177 -0.233 0.227 0.281 0.089 0.187 0.323

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

N 1270 2249 2270 1908 2010 2310 2273 2170 2170

Coliform Coefficient -0.340 -0.282 -0.336 0.263 0.341 0.089 0.043 0.312

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.000 0.026 0.000

N 1575 2768 2792 2366 2508 2273 2839 2674 2674

Turbidity Coefficient -0.343 0.027 0.198 0.197 0.095 0.187 0.043 0.041

p (2-tailed) 0.000 0.170 0.000 0.000 0.000 0.000 0.026 0.033

N 1497 2652 2675 2281 2406 2170 2674 2720 2719

Color Coefficient -0.451 -0.260 -0.711 0.514 0.484 0.323 0.312 0.041

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.033

N 1497 2652 2675 2280 2406 2170 2674 2719 2721

Bold values significant at the 0.05 level
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XLVII 

Table D.2: Spearman's rho correlation for selected variables in the dry verus the rainy season for the entire study region 

 Secchi DO Salinity TN TP ChlA Coliform Turbidity Color

Secchi Coefficient 0.322 0.479 -0.421 -0.585 -0.305 -0.400 -0.218 -0.585

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

N 978 904 913 611 649 597 757 703 703

DO Coefficient 0.219 0.129 -0.220 -0.247 0.020 -0.431 0.021 -0.217

p (2-tailed) 0.000 0.000 0.000 0.000 0.552 0.000 0.488 0.000

N 954 2000 1358 926 983 870 1124 1052 1052

Salinity Coefficient 0.164 -0.041 -0.367 -0.489 -0.134 -0.403 0.183 -0.722

p (2-tailed) 0.000 0.072 0.000 0.000 0.000 0.000 0.000 0.000

N 966 1971 2014 937 990 882 1136 1064 1064

TN Coefficient -0.262 -0.042 -0.319 0.368 0.254 0.282 0.201 0.550

p (2-tailed) 0.000 0.112 0.000 0.000 0.000 0.000 0.000 0.000

N 684 1408 1417 1446 911 713 938 869 868

TP Coefficient -0.408 -0.100 -0.412 0.339 0.241 0.395 0.142 0.560

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

N 719 1494 1505 1409 1531 759 995 936 936

ChlA Coefficient -0.327 -0.124 -0.226 0.104 0.302 0.101 0.230 0.136

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.003 0.000 0.000

N 673 1379 1388 1195 1251 1412 881 818 818

Coliform Coefficient -0.265 -0.248 -0.316 0.263 0.306 0.085 0.098 0.439

p (2-tailed) 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.000

N 818 1644 1656 1428 1513 1392 1683 1059 1059

Turbidity Coefficient -0.481 0.000 0.204 0.213 0.067 0.187 0.008 0.068

p (2-tailed) 0.000 0.991 0.000 0.000 0.010 0.000 0.759 0.025

N 794 1600 1611 1412 1470 1384 1615 1638 1081

Color Coefficient -0.272 -0.083 -0.696 0.430 0.430 0.337 0.271 0.033

p (2-tailed) 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.181

N 794 1600 1611 1412 1470 1352 1615 1638 1638

Bold values significant at the 0.05 level

Rainy season

Dry Season
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XLVIII 

Table D.3: Spearman's rho correlation for selected variables in Upper Lemon Bay

 Secchi DO Salinity TN TP Chl a Coliform Turbidity Color

Secchi Coefficient 0.1794 0.0891 -0.1403 -0.1708 -0.2634 -0.0053 -0.2528 -0.1304

p (2-tailed) 0.0241 0.2658 0.2004 0.1226 0.0215 0.9594 0.0175 0.2287

N 161 158 158 85 83 76 96 88 87

DO Coefficient 0.1794 0.2109 -0.2522 -0.3575 -0.1140 -0.2121 -0.0160 -0.3463

p (2-tailed) 0.0241 0.0000 0.0002 0.0000 0.1040 0.0007 0.8060 0.0000

N 158 373 369 216 225 206 250 237 236

Salinity Coefficient 0.0891 0.2109 -0.3894 -0.3615 -0.0650 -0.5709 0.1350 -0.6865

p (2-tailed) 0.2658 0.0000 0.0000 0.0000 0.3540 0.0000 0.0360 0.0000

N 158 369 376 218 227 208 251 239 238

TN Coefficient -0.1403 -0.2522 -0.3894 0.4211 0.2470 0.2661 0.2970 0.5788

p (2-tailed) 0.2004 0.0002 0.0000 0.0000 0.0010 0.0001 0.0000 0.0000

N 85 216 218 219 212 177 215 206 205

TP Coefficient -0.1708 -0.3575 -0.3615 0.4211 0.1270 0.2894 0.1480 0.4892

p (2-tailed) 0.1226 0.0000 0.0000 0.0000 0.0870 0.0000 0.0310 0.0000

N 83 225 227 212 228 183 224 213 213

Chl a Coefficient -0.2634 -0.1140 -0.0650 0.2470 0.1270 0.0720 0.3880 0.1400

p (2-tailed) 0.0215 0.1040 0.3520 0.0010 0.0870 0.3030 0.0000 0.0530

N 76 206 208 177 183 209 204 193 192

Coliform Coefficient -0.0053 -0.2121 -0.5709 0.2661 0.2894 0.0720 0.0480 0.4395

p (2-tailed) 0.9594 0.0007 0.0000 0.0001 0.0000 0.3030 0.4590 0.0000

N 96 250 251 215 224 204 252 236 235

Turbidity Coefficient -0.2528 -0.0160 0.1350 0.2970 0.1480 0.3880 0.0480 0.2200

p (2-tailed) 0.0175 0.8060 0.0360 0.0000 0.0310 0.0000 0.4590 0.0010

N 88 237 239 206 213 193 236 240 239

Color Coefficient -0.1304 -0.3463 -0.6865 0.5788 0.4892 0.1400 0.4395 0.2200

p (2-tailed) 0.2287 0.0000 0.0000 0.0000 0.0000 0.0530 0.0000 0.0010

N 87 236 238 205 213 192 235 239 239

Bold values significant at the 0.05 level
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

XLIX 

Table D.4: Spearman's rho correlation for selected variables in Lower Lemon Bay

 Secchi DO Salinity TN TP Chl a Coliform Turbidity Color

Secchi Coefficient 0.2380 0.1317 -0.2108 -0.2463 -0.2710 -0.2163 -0.3913 -0.2351

p (2-tailed) 0.0003 0.0481 0.0220 0.0067 0.0030 0.0103 0.0000 0.0062

N 230 224 226 118 120 118 140 134 134

DO Coefficient 0.2380 0.2010 -0.2328 -0.2072 -0.2230 -0.4253 0.1029 -0.4576

p (2-tailed) 0.0003 0.0000 0.0002 0.0007 0.0000 0.0000 0.0834 0.0000

N 224 515 508 256 267 245 291 284 284

Salinity Coefficient 0.1317 0.2010 -0.2180 -0.3063 -0.2360 -0.3316 0.1848 -0.4521

p (2-tailed) 0.0481 0.0000 0.0004 0.0000 0.0000 0.0000 0.0016 0.0000

N 226 508 518 260 270 249 297 290 290

TN Coefficient -0.2108 -0.2328 -0.2180 0.3052 0.2740 0.2615 0.0767 0.5015

p (2-tailed) 0.0220 0.0002 0.0004 0.0000 0.0000 0.0000 0.2234 0.0000

N 118 256 260 265 257 217 259 254 254

TP Coefficient -0.2463 -0.2072 -0.3063 0.3052 0.2550 0.3244 0.1974 0.3759

p (2-tailed) 0.0067 0.0007 0.0000 0.0000 0.0000 0.0000 0.0013 0.0000

N 120 267 270 257 275 223 267 263 263

Chl a Coefficient -0.2710 -0.2230 -0.2360 0.2740 0.2550 0.1910 0.1410 0.4180

p (2-tailed) 0.0030 0.0000 0.0000 0.0000 0.0000 0.0030 0.0300 0.0000

N 118 245 249 217 223 255 247 240 240

Coliform Coefficient -0.2163 -0.4253 -0.3316 0.2615 0.3244 0.1910 0.0455 0.3982

p (2-tailed) 0.0103 0.0000 0.0000 0.0000 0.0000 0.0030 0.4433 0.0000

N 140 291 297 259 267 247 302 286 286

Turbidity Coefficient -0.3913 0.1029 0.1848 0.0767 0.1974 0.1410 0.0455 -0.0121

p (2-tailed) 0.0000 0.0834 0.0016 0.2234 0.0013 0.0300 0.4433 0.8355

N 134 284 290 254 263 244 286 296 296

Color Coefficient -0.2351 -0.4576 -0.4521 0.5015 0.3759 0.4180 0.3982 -0.0121

p (2-tailed) 0.0062 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.8355

N 134 284 290 254 263 240 286 296 296

Bold values significant at the 0.05 level
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

L 

Table D.5: Spearman's rho correlation for selected variables in Upper Charlotte Harbor

 Secchi DO Salinity TN TP Chl a Coliform Turbidity Color

Secchi Coefficient 0.1742 0.5457 -0.4034 -0.4700 -0.0258 -0.2263 -0.2544 -0.5517

p (2-tailed) 0.0006 0.0000 0.0000 0.0000 0.6653 0.0000 0.0000 0.0000

N 394 387 387 291 305 283 336 315 315

DO Coefficient 0.1742 0.1667 -0.1395 -0.1219 0.0360 -0.0690 0.0925 -0.2799

p (2-tailed) 0.0006 0.0000 0.0019 0.0053 0.4318 0.0977 0.0307 0.0000

N 387 650 638 494 522 479 577 546 546

Salinity Coefficient 0.5457 0.1667 -0.4394 -0.5787 -0.2954 -0.2179 -0.0606 -0.7445

p (2-tailed) 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.1585 0.0000

N 387 638 649 491 519 479 575 543 543

TN Coefficient -0.4034 -0.1395 -0.4394 0.4150 0.2349 0.1396 0.3917 0.5741

p (2-tailed) 0.0000 0.0019 0.0000 0.0000 0.0000 0.0018 0.0000 0.0000

N 291 494 491 505 484 419 500 476 476

TP Coefficient -0.4700 -0.1219 -0.5787 0.4150 0.3602 0.0906 0.3163 0.5686

p (2-tailed) 0.0000 0.0053 0.0000 0.0000 0.0000 0.0378 0.0000 0.0000

N 305 522 519 484 532 436 526 504 504

Chl a Coefficient -0.0258 0.0360 -0.2954 0.2349 0.3602 -0.0205 0.3724 0.2433

p (2-tailed) 0.6653 0.4318 0.0000 0.0000 0.0000 0.6529 0.0000 0.0000

N 283 479 479 419 436 489 485 453 453

Coliform Coefficient -0.2263 -0.0690 -0.2179 0.1396 0.0906 -0.0205 0.0294 0.0723

p (2-tailed) 0.0000 0.0977 0.0000 0.0018 0.0378 0.6529 0.4929 0.0907

N 336 577 575 500 526 485 587 548 548

Turbidity Coefficient -0.2544 0.0925 -0.0606 0.3917 0.3163 0.3724 0.0294 0.2101

p (2-tailed) 0.0000 0.0307 0.1585 0.0000 0.0000 0.0000 0.4929 0.0000

N 315 546 543 476 504 453 548 556 556

Color Coefficient -0.5517 -0.2799 -0.7445 0.5741 0.5686 0.2433 0.0723 0.2101

p (2-tailed) 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0907 0.0000

N 315 546 543 476 504 453 548 556 557

Bold values significant at the 0.05 level
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

LI 

Table D.6: Spearman's rho correlation for selected variables in Lower Charlotte Harbor

 Secchi DO Salinity TN TP Chl a Coliform Turbidity Color

Secchi Coefficient 0.4226 0.5633 -0.3260 -0.3642 -0.5760 -0.5032 -0.2659 -0.5814

p (2-tailed) 0.0000 0.0000 0.0028 0.0007 0.0000 0.0000 0.0104 0.0000

N 105 101 102 81 83 79 96 92 92

DO Coefficient 0.4226 -0.0467 -0.3340 -0.0830 -0.2140 -0.2384 -0.1348 -0.1889

p (2-tailed) 0.0000 0.4694 0.0000 0.2285 0.0030 0.0003 0.0452 0.0048

N 101 247 242 202 212 193 229 221 221

Salinity Coefficient 0.5633 -0.0467 -0.3290 -0.4297 -0.2560 -0.1188 0.1900 -0.7352

p (2-tailed) 0.0000 0.4694 0.0000 0.0000 0.0000 0.0734 0.0047 0.0000

N 102 242 248 201 209 192 228 220 220

TN Coefficient -0.3260 -0.3340 -0.3290 0.2520 0.2220 0.2960 0.1790 0.4372

p (2-tailed) 0.0028 0.0000 0.0000 0.0000 0.0000 0.0000 0.0120 0.0000

N 81 202 201 207 200 170 201 195 195

TP Coefficient -0.3642 -0.0830 -0.4297 0.2520 0.2330 0.1014 -0.0223 0.5099

p (2-tailed) 0.0007 0.2285 0.0000 0.0000 0.0020 0.1420 0.7512 0.0000

N 83 212 209 200 215 176 211 204 204

Chl a Coefficient -0.5756 -0.1948 -0.2297 0.2220 0.2222 0.1528 0.2697 0.3337

p (2-tailed) 0.0000 0.0064 0.0013 0.0040 0.0029 0.0330 0.0002 0.0000

N 79 195 194 170 178 198 195 187 187

Coliform Coefficient -0.5032 -0.2384 -0.1188 0.2960 0.1014 0.1240 0.1753 0.1667

p (2-tailed) 0.0000 0.0003 0.0734 0.0000 0.1420 0.0850 0.0092 0.0133

N 96 229 228 201 211 193 234 220 220

Turbidity Coefficient -0.2659 -0.1348 0.1900 0.1790 -0.0223 0.2020 0.1753 0.0435

p (2-tailed) 0.0104 0.0452 0.0047 0.0120 0.7512 0.0060 0.0092 0.5154

N 92 221 220 195 204 185 220 226 226

Color Coefficient -0.5814 -0.1889 -0.7352 0.4372 0.5099 0.3980 0.1667 0.0435

p (2-tailed) 0.0000 0.0048 0.0000 0.0000 0.0000 0.0000 0.0133 0.5154

N 92 221 220 195 204 185 220 226 226

Bold values significant at the 0.05 level
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

LII 

Table D.7: Spearman's rho correlation for selected variables in Gasparilla/Cape Haze

 Secchi DO Salinity TN TP Chl a Coliform Turbidity Color

Secchi Coefficient 0.1842 0.0355 -0.2860 -0.1644 -0.1760 0.0837 0.2325 -0.1934

p (2-tailed) 0.0998 0.7455 0.0270 0.1941 0.1480 0.4722 0.0462 0.0988

N 86 81 86 60 64 69 76 74 74

DO Coefficient 0.1842 -0.1229 -0.0960 0.1414 0.0510 -0.2269 0.0198 -0.2226

p (2-tailed) 0.0998 0.0957 0.2680 0.0910 0.5500 0.0036 0.8066 0.0052

N 81 188 185 134 144 140 163 156 156

Salinity Coefficient 0.0355 -0.1229 -0.1531 -0.4247 -0.2080 -0.0005 0.3341 -0.5491

p (2-tailed) 0.7455 0.0957 0.0752 0.0000 0.0130 0.9953 0.0000 0.0000

N 86 185 192 136 147 143 166 159 159

TN Coefficient -0.2860 -0.0960 -0.1531 0.2062 -0.0300 -0.0430 -0.0640 0.3240

p (2-tailed) 0.0270 0.2680 0.0752 0.0157 0.7480 0.6170 0.4710 0.0000

N 60 134 136 141 137 117 136 131 131

TP Coefficient -0.1644 0.1414 -0.4247 0.2062 0.2120 -0.1839 0.0245 0.3418

p (2-tailed) 0.1941 0.0910 0.0000 0.0157 0.0180 0.0257 0.7723 0.0000

N 64 144 147 137 150 124 147 142 142

Chl a Coefficient -0.1760 0.0510 -0.2080 -0.0300 0.2120 -0.1030 0.1800 0.2230

p (2-tailed) 0.1480 0.5500 0.0130 0.7480 0.0180 0.2240 0.0360 0.0090

N 69 140 143 117 124 145 142 136 137

Coliform Coefficient 0.0837 -0.2269 -0.0005 -0.0430 -0.1839 -0.1030 -0.0545 0.0498

p (2-tailed) 0.4722 0.0036 0.9953 0.6170 0.0257 0.2240 0.4978 0.5358

N 76 163 166 136 147 142 169 157 157

Turbidity Coefficient -0.2325 0.0198 0.3341 -0.0640 0.0245 0.1800 -0.0545 -0.0451

p (2-tailed) 0.0462 0.8066 0.0000 0.4710 0.7723 0.0360 0.4978 0.5685

N 74 156 159 131 142 136 157 162 162

Color Coefficient -0.1934 -0.2226 -0.5491 0.3240 0.3418 0.2230 0.0498 -0.0451

p (2-tailed) 0.0988 0.0052 0.0000 0.0000 0.0000 0.0090 0.5358 0.5685

N 74 156 159 131 142 136 157 162 162

Bold values significant at the 0.05 level
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

LIII 

Table D.8: Spearman's rho correlation for selected variables in Pine Island Sound

 Secchi DO Salinity TN TP Chl a Coliform Turbidity Color

Secchi Coefficient 0.1479 0.0432 -0.1887 -0.3218 -0.2870 -0.0022 -0.5720 -0.1609

p (2-tailed) 0.0587 0.5794 0.0425 0.0002 0.0010 0.9780 0.0000 0.0469

N 167 164 167 116 126 121 160 152 153

DO Coefficient 0.1479 0.0151 -0.1717 -0.1762 -0.4020 -0.1943 0.1488 -0.3338

p (2-tailed) 0.0587 0.7668 0.0031 0.0016 0.0000 0.0002 0.0048 0.0000

N 164 392 390 294 317 291 368 357 358

Salinity Coefficient 0.0432 0.0151 -0.2228 -0.1254 -0.2190 -0.0310 0.2771 -0.4968

p (2-tailed) 0.5794 0.7668 0.0001 0.0240 0.0000 0.5498 0.0000 0.0000

N 167 390 399 301 324 293 375 364 365

TN Coefficient -0.1887 -0.1717 -0.2228 0.2459 0.1780 0.2077 0.1911 0.4128

p (2-tailed) 0.0425 0.0031 0.0001 0.0000 0.0070 0.0002 0.0010 0.0000

N 116 294 301 309 299 232 307 295 295

TP Coefficient -0.3218 -0.1762 -0.1254 0.2459 0.1520 0.2394 0.1608 0.3560

p (2-tailed) 0.0002 0.0016 0.0240 0.0000 0.0160 0.0000 0.0043 0.0000

N 126 317 324 299 330 250 329 313 313

Chl a Coefficient -0.2870 -0.4020 -0.2190 0.1780 0.1520 -0.0480 0.2040 0.3590

p (2-tailed) 0.0010 0.0000 0.0000 0.0070 0.0160 0.4150 0.0010 0.0000

N 121 291 293 232 250 298 295 283 284

Coliform Coefficient -0.0022 -0.1943 -0.0310 0.2077 0.2394 -0.0480 0.0215 0.1160

p (2-tailed) 0.9780 0.0002 0.5498 0.0002 0.0000 0.4150 0.6824 0.0266

N 160 368 375 307 329 295 383 364 365

Turbidity Coefficient -0.5720 0.1488 0.2771 0.1911 0.1608 0.2040 0.0215 -0.0581

p (2-tailed) 0.0000 0.0048 0.0000 0.0010 0.0043 0.0010 0.6824 0.2667

N 152 357 364 295 313 283 364 368 368

Color Coefficient -0.1609 -0.3338 -0.4968 0.4128 0.3560 0.3590 0.1160 -0.0581

p (2-tailed) 0.0469 0.0000 0.0000 0.0000 0.0000 0.0000 0.0266 0.2667

N 153 358 365 295 313 284 365 368 369

Bold values significant at the 0.05 level
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

LIV 

Table D.9: Spearman's rho correlation for selected variables in Matlacha Pass

 Secchi DO Salinity TN TP Chl a Coliform Turbidity Color

Secchi Coefficient 0.2769 0.5274 -0.3613 -0.3855 -0.3210 0.0323 -0.4121 -0.5237

p (2-tailed) 0.0001 0.0000 0.0000 0.0000 0.0000 0.6665 0.0000 0.0000

N 202 195 199 147 160 141 180 171 171

DO Coefficient 0.2769 0.0670 -0.0883 -0.2256 -0.2500 -0.1036 -0.3778 -0.1723

p (2-tailed) 0.0001 0.2921 0.2295 0.0012 0.0010 0.1203 0.0000 0.0116

N 195 252 249 187 203 179 226 214 214

Salinity Coefficient 0.5274 0.0670 -0.3255 -0.2146 -0.3050 -0.0792 -0.1227 -0.7282

p (2-tailed) 0.0000 0.2921 0.0000 0.0019 0.0000 0.2317 0.0712 0.0000

N 199 249 258 192 208 183 230 217 217

TN Coefficient -0.3613 -0.0883 -0.3255 0.2701 0.0680 0.2605 0.4056 0.5094

p (2-tailed) 0.0000 0.2295 0.0000 0.0002 0.4100 0.0003 0.0000 0.0000

N 147 187 192 194 187 149 191 184 184

TP Coefficient -0.3855 -0.2256 -0.2146 0.2701 0.0490 0.0704 0.2516 0.3566

p (2-tailed) 0.0000 0.0012 0.0019 0.0002 0.5340 0.3111 0.0004 0.0000

N 160 203 208 187 212 161 209 197 197

Chl a Coefficient -0.3210 -0.2500 -0.3050 0.0680 0.0490 -0.2020 0.2640 0.2170

p (2-tailed) 0.0000 0.0010 0.0000 0.4100 0.5340 0.0060 0.0000 0.0040

N 141 179 183 149 161 187 182 176 176

Coliform Coefficient 0.0323 -0.1036 -0.0792 0.2605 0.0704 -0.2020 0.1830 0.1561

p (2-tailed) 0.6665 0.1203 0.2317 0.0003 0.3111 0.0060 0.0069 0.0215

N 180 226 230 191 209 182 234 217 217

Turbidity Coefficient -0.4121 -0.3778 -0.1227 0.4056 0.2516 0.2640 0.1830 0.3932

p (2-tailed) 0.0000 0.0000 0.0712 0.0000 0.0004 0.0000 0.0069 0.0000

N 171 214 217 184 197 176 217 221 221

Color Coefficient -0.5237 -0.1723 -0.7282 0.5094 0.3566 0.2170 0.1561 0.3932

p (2-tailed) 0.0000 0.0116 0.0000 0.0000 0.0000 0.0040 0.0215 0.0000

N 171 214 217 184 197 176 217 221 221

Bold values significant at the 0.05 level
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

LV 

Table D.10: Spearman's rho correlation for selected variables in San Carlos Bay

 Secchi DO Salinity TN TP Chl a Coliform Turbidity Color

Secchi Coefficient 0.2182 0.0361 -0.1929 -0.2389 -0.1680 -0.2603 -0.4491 -0.2170

p (2-tailed) 0.0001 0.5162 0.0029 0.0001 0.0100 0.0000 0.0000 0.0002

N 327 319 325 237 251 234 297 282 282

DO Coefficient 0.2182 0.0146 -0.0906 -0.1990 -0.0580 -0.0799 -0.0783 -0.1640

p (2-tailed) 0.0001 0.7917 0.1581 0.0013 0.3710 0.1670 0.1875 0.0055

N 319 334 331 244 257 237 301 285 285

Salinity Coefficient 0.0361 0.0146 -0.3314 -0.0186 -0.1040 -0.0432 0.4109 -0.6108

p (2-tailed) 0.5162 0.7917 0.0000 0.7661 0.1080 0.4515 0.0000 0.0000

N 325 331 339 246 259 242 306 290 290

TN Coefficient -0.1929 -0.0906 -0.3314 0.2252 0.0440 0.1549 0.2260 0.4702

p (2-tailed) 0.0029 0.1581 0.0000 0.0005 0.5480 0.0146 0.0004 0.0000

N 237 244 246 249 237 191 248 240 240

TP Coefficient -0.2389 -0.1990 -0.0186 0.2252 -0.0890 0.1266 0.1769 0.1278

p (2-tailed) 0.0001 0.0013 0.7661 0.0005 0.2090 0.0406 0.0052 0.0444

N 251 257 259 237 263 202 262 248 248

Chl a Coefficient -0.1680 -0.5800 -0.1040 0.0440 -0.0890 0.0690 0.0310 0.2740

p (2-tailed) 0.0100 0.3710 0.1080 0.5480 0.2090 0.2840 0.6430 0.0000

N 234 237 242 191 202 245 243 231 231

Coliform Coefficient -0.2603 -0.0799 -0.0432 0.1549 0.1266 0.0690 0.1744 0.1168

p (2-tailed) 0.0000 0.1670 0.4515 0.0146 0.0406 0.2840 0.0028 0.0462

N 297 301 306 248 262 243 310 292 292

Turbidity Coefficient -0.4491 -0.0783 0.4109 0.2260 0.1769 0.0310 0.1744 -0.0128

p (2-tailed) 0.0000 0.1875 0.0000 0.0004 0.0052 0.6430 0.0028 0.8275

N 282 285 290 240 248 231 292 294 294

Color Coefficient -0.2170 -0.1640 -0.6108 0.4702 0.1278 0.2740 0.1168 -0.0128

p (2-tailed) 0.0002 0.0055 0.0000 0.0000 0.0444 0.0000 0.0462 0.8275

N 282 285 290 240 248 231 292 294 294

Bold values significant at the 0.05 level
Appendix D CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

LVI 

Table D.11: Spearman's rho correlation for selected variables in Estero Bay

 Secchi DO Salinity TN TP Chl a Coliform Turbidity Color

Secchi Coefficient -0.0978 -0.3888 -0.0133 -0.3604 -0.2570 0.4268 -0.6045 0.1251

p (2-tailed) 0.1953 0.0000 0.8799 0.0000 0.0030 0.0000 0.0000 0.1162

N 177 177 176 131 146 130 165 159 159

DO Coefficient -0.0978 0.0793 -0.1539 0.0372 -0.2290 -0.0639 0.2583 -0.2236

p (2-tailed) 0.1953 0.1382 0.0113 0.5265 0.0000 0.2497 0.0000 0.0001

N 177 356 351 270 292 258 326 314 314

Salinity Coefficient -0.3888 0.0793 -0.2331 0.2954 -0.0220 -0.4179 0.4613 -0.6134

p (2-tailed) 0.0000 0.1382 0.0001 0.0000 0.7260 0.0000 0.0000 0.0000

N 176 351 357 272 294 260 327 315 315

TN Coefficient -0.0133 -0.1539 -0.2331 0.1748 0.1400 0.1974 0.1216 0.4567

p (2-tailed) 0.8799 0.0113 0.0001 0.0040 0.0390 0.0010 0.0488 0.0000

N 131 270 272 276 270 216 273 263 263

TP Coefficient -0.3604 0.0372 0.2954 0.1748 0.0900 -0.0386 0.4315 -0.0650

p (2-tailed) 0.0000 0.5265 0.0000 0.0040 0.1690 0.5078 0.0000 0.2749

N 146 292 294 270 297 234 296 284 284

Chl a Coefficient -0.2570 -0.2290 -0.0220 0.1400 0.0900 -0.0770 0.1240 0.0410

p (2-tailed) 0.0030 0.0000 0.7260 0.0390 0.1690 0.2120 0.0490 0.5130

N 130 258 260 216 234 263 262 252 252

Coliform Coefficient 0.4268 -0.0639 -0.4179 0.1974 -0.0386 -0.0770 -0.1772 0.2752

p (2-tailed) 0.0000 0.2497 0.0000 0.0010 0.5078 0.2120 0.0015 0.0000

N 165 326 327 273 296 262 331 317 317

Turbidity Coefficient -0.6045 0.2583 0.4613 0.1216 0.4315 0.1240 -0.1772 -0.1084

p (2-tailed) 0.0000 0.0000 0.0000 0.0488 0.0000 0.0490 0.0015 0.0530

N 159 314 315 263 284 252 317 319 319

Color Coefficient 0.1251 -0.2236 -0.6134 0.4567 -0.0650 0.0410 0.2752 -0.1084

p (2-tailed) 0.1162 0.0001 0.0000 0.0000 0.2749 0.5130 0.0000 0.0530

N 159 314 315 263 284 252 317 319 319

Bold values significant at the 0.05 level
Appendix E CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

LVII 

Appendix E: Rainfall Relationships 

 Page 

Table E.1: Spearman's rho correlation for selected variables for the entire study region 

and duration _____________________________________________ LVIII 
Appendix E CHEVWQMN Report 2007 

Charlotte Harbor Aquatic Preserves, Florida Department of Environmental Protection 

LVIII 

Table E.1: Spearman's rho correlation for rainfall for the entire region and individual regions for the duration of the study

 Secchi pH Salinity TN TP Chl a Coliform Turbidity Color

Entire Region Coefficient -0.038 -0.911 -0.858 -0.116 0.493 0.276 0.182 -64.000 0.588

p (2-tailed) 0.929 0.002 0.006 0.785 0.214 0.549 0.665 0.087 0.125

N 888887888

Lower Lemon Bay Coefficient 0.221 -0.228 -0.717 -0.506 0.079 -0.236 -0.172 -0.533 0.242

p (2-tailed) 0.598 0.587 0.045 0.200 0.853 0.610 0.683 0.174 0.564

N 888887888

Upper Lemon Bay Coefficient -0.072 -0.634 -0.861 0.190 0.406 0.272 0.084 0.146 0.413

p (2-tailed) 0.865 0.092 0.006 0.965 0.318 0.555 0.844 0.731 0.310

N 888887888

Lower Charlotte Harbor* Coefficient -0.383 -0.749 -0.769 -0.427 0.689 0.540 -0.211 -0.589 0.624

p (2-tailed) 0.349 0.032 0.026 0.292 0.059 0.211 0.615 0.125 0.098

N 888887888

Upper Charlotte Harbor* Coefficient -0.217 -0.575 -0.719 -0.089 0.878 0.249 -0.075 -0.217 0.509

p (2-tailed) 0.605 0.136 0.044 0.834 0.004 0.591 0.860 0.606 0.198

N 888887888

Gasparilla/Cape Haze* Coefficient -0.041 -0.728 -0.902 0.139 0.557 0.131 0.260 -0.697 0.668

p (2-tailed) 0.924 0.041 0.002 0.742 0.151 0.780 0.534 0.055 0.070

N 888887888

Pine Island Sound** Coefficient 0.222 -0.838 -0.909 0.084 0.390 0.123 0.203 -0.655 0.801

p (2-tailed) 0.598 0.009 0.002 0.844 0.340 0.793 0.629 0.078 0.017

N 888887888

Matlacha Pass** Coefficient -0.417 -0.139 -0.762 -0.270 0.299 0.181 -0.467 -0.281 0.709

p (2-tailed) 0.304 0.743 0.028 0.518 0.472 0.697 0.244 0.500 0.049

N 888887888

San Carlos Bay*** Coefficient -0.134 -0.797 -0.822 -0.034 0.008 0.375 0.121 -0.163 0.693

p (2-tailed) 0.751 0.018 0.012 0.937 0.984 0.408 0.775 0.700 0.057

N 888887888

Estero Bay Coefficient 0.188 -0.366 -0.428 -0.055 -0.644 0.328 0.093 -0.385 0.139

p (2-tailed) 0.655 0.372 0.291 0.898 0.085 0.472 0.826 0.347 0.742

N 888887888

* Average annual rainfall for Charlotte Harbor + Myakka + Peace

** Average annual rainfall for Charlotte Harbor + Tidal Caloosahatchee

*** Average annual rainfall for Tidal Caloosahatchee

Bold values significant at the 0.05 level