Funding & Acknowledgements

The data used in this analysis is from the Export Standardized Tables in the SEACAR Data Discovery Interface (DDI). Documents and information available through the SEACAR DDI are owned by the data provider(s) and users are expected to provide appropriate credit following accepted citation formats. Users are encouraged to access data to maximize utilization of gained knowledge, reducing redundant research and facilitating partnerships and scientific innovation.

With respect to documents and information available from SEACAR DDI, neither the State of Florida nor the Florida Department of Environmental Protection makes any warranty, expressed or implied, including the warranties of merchantability and fitness for a particular purpose arising out of the use or inability to use the data, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights.

This report was funded in part, through a grant agreement from the Florida Department of Environmental Protection, Florida Coastal Management Program, by a grant provided by the Office for Coastal Management under the Coastal Zone Management Act of 1972, as amended, National Oceanic and Atmospheric Administration. The views, statements, findings, conclusions and recommendations expressed herein are those of the author(s) and do not necessarily reflect the views of the State of Florida, NOAA or any of their sub agencies.

Published: 2025-10-08

Threshold Filtering

Threshold filters, following the guidance of Florida Department of Environmental Protection’s (FDEP) Division of Environmental Assessment and Restoration (DEAR) are used to exclude specific results values from the SEACAR Analysis. Based on the threshold filters, Quality Assurance / Quality Control (QAQC) Flags are inserted into the SEACAR_QAQCFlagCode and SEACAR_QAQC_Description columns of the export data. The Include column indicates whether the QAQC Flag will also indicate that data are excluded from analysis. No data are excluded from the data export, but the analysis scripts can use the Include column to exclude data (1 to include, 0 to exclude).

Continuous Water Quality threshold values
Parameter Name Units Low Threshold High Threshold
Dissolved Oxygen mg/L -0.000001 50
Dissolved Oxygen Saturation % -0.000001 500
Salinity ppt -0.000001 70
Turbidity NTU -0.000001 4000
Water Temperature Degrees C -5.000000 45
pH None 2.000000 14
Discrete Water Quality threshold values
Parameter Name Units Low Threshold High Threshold
Ammonia, Un-ionized (NH3) mg/L - -
Ammonium, Filtered (NH4) mg/L - -
Chlorophyll a, Corrected for Pheophytin ug/L - -
Chlorophyll a, Uncorrected for Pheophytin ug/L - -
Colored Dissolved Organic Matter PCU - -
Dissolved Oxygen mg/L -0.000001 25
Dissolved Oxygen Saturation % -0.000001 310
Fluorescent Dissolved Organic Matter QSE - -
Light Extinction Coefficient m^-1 - -
NO2+3, Filtered mg/L - -
Nitrate (NO3) mg/L - -
Nitrite (NO2) mg/L - -
Nitrogen, organic mg/L - -
Phosphate, Filtered (PO4) mg/L - -
Salinity ppt -0.000001 70
Secchi Depth m 0.000001 50
Specific Conductivity mS/cm 0.005000 100
Total Kjeldahl Nitrogen mg/L - -
Total Nitrogen mg/L - -
Total Nitrogen mg/L - -
Total Phosphorus mg/L - -
Total Suspended Solids mg/L - -
Turbidity NTU - -
Water Temperature Degrees C 3.000000 40
pH None 2.000000 13
Quality Assurance Flags inserted based on threshold checks listed in Table 1 and 2
SEACAR QAQC Description Include SEACAR QAQCFlagCode
Exceeds maximum threshold 0 2Q
Below minimum threshold 0 4Q
Within threshold tolerance 1 6Q
No defined thresholds for this parameter 1 7Q

Value Qualifiers

Value qualifier codes included within the data are used to exclude certain results from the analysis. The data are retained in the data export files, but the analysis uses the Include column to filter the results.

STORET and WIN value qualifier codes

Value qualifier codes from STORET and WIN data are examined with the database and used to populate the Include column in data exports.

Value Qualifier codes excluded from analysis
Qualifier Source Value Qualifier Include MDL Description
STORET-WIN H 0 0 Value based on field kit determination; results may not be accurate
STORET-WIN J 0 0 Estimated value
STORET-WIN V 0 0 Analyte was detected at or above method detection limit
STORET-WIN Y 0 0 Lab analysis from an improperly preserved sample; data may be inaccurate

Discrete Water Quality Value Qualifiers

The following value qualifiers are highlighted in the Discrete Water Quality section of this report. An exception is made for Program 476 - Charlotte Harbor Estuaries Volunteer Water Quality Monitoring Network and data flagged with Value Qualifier H are included for this program only.

H - Value based on field kit determiniation; results may not be accurate. This code shall be used if a field screening test (e.g., field gas chromatograph data, immunoassay, or vendor-supplied field kit) was used to generate the value and the field kit or method has not been recognized by the Department as equivalent to laboratory methods.

I - The reported value is greater than or equal to the laboratory method detection limit but less than the laboratory practical quantitation limit.

Q - Sample held beyond the accepted holding time. This code shall be used if the value is derived from a sample that was prepared or analyzed after the approved holding time restrictions for sample preparation or analysis.

S - Secchi disk visible to bottom of waterbody. The value reported is the depth of the waterbody at the location of the Secchi disk measurement.

U - Indicates that the compound was analyzed for but not detected. This symbol shall be used to indicate that the specified component was not detected. The value associated with the qualifier shall be the laboratory method detection limit. Unless requested by the client, less than the method detection limit values shall not be reported

Systemwide Monitoring Program (SWMP) value qualifier codes

Value qualifier codes from the SWMP continuous program are examined with the database and used to populate the Include column in data exports. SWMP Qualifier Codes are indicated by QualifierSource=SWMP.

SWMP Value Qualifier codes
Qualifier Source Value Qualifier Include Description
SWMP -1 1 Optional parameter not collected
SWMP -2 0 Missing data
SWMP -3 0 Data rejected due to QA/QC
SWMP -4 0 Outside low sensor range
SWMP -5 0 Outside high sensor range
SWMP 0 1 Passed initial QA/QC checks
SWMP 1 0 Suspect data
SWMP 2 1 Reserved for future use
SWMP 3 1 Calculated data: non-vented depth/level sensorcorrection for changes in barometric pressure
SWMP 4 1 Historical: Pre-auto QA/QC
SWMP 5 1 Corrected data

Water Column

The water column habitat extends from the water’s surface to the bottom sediments, and it’s where fish, dolphins, crabs and people swim! So much life makes its home in the water column that the health of marine and coastal ecosystems, as well as human economies, depend on the condition of this vulnerable habitat. Local patterns of rainfall, temperature, winds and currents can rapidly change the condition of the water column, while global influences such as El Niño/La Niña, large-scale fluctuation in sea temperatures and climate change can have long-term effects. Inputs from the prosperity of our day-to-day lives including farming, mining and forestry, and emissions from power generation, automobiles and water treatment can also alter the health of the water column. Acting alone or together, each input can have complex and lasting effects on habitats and ecosystems.


SEACAR evaluates water column health with several essential parameters. These include nutrient surveys of nitrogen and phosphorus, and water quality assessments of salinity, dissolved oxygen, pH, and water temperature. Water clarity is evaluated with Secchi depth, turbidity, levels of chlorophyll a, total suspended solids, and colored dissolved organic matter. Additionally, the richness of nekton is indicated by the abundance of free-swimming fishes and macroinvertebrates like crabs and shrimps.

Seasonal Kendall-Tau Analysis

Indicators must have a minimum of five to ten years, depending on the habitat, of data within the geographic range of the analysis to be included in the analysis. Ten years of data are required for discrete parameters, and five years of data are required for continuous parameters. If there are insufficient years of data, the number of years of data available will be noted and labeled as “insufficient data to conduct analysis”. Further, for the preferred Seasonal Kendall-Tau test, there must be data from at least two months in common across at least two consecutive years within the RCP managed area being analyzed. Values that pass both of these tests will be included in the analysis and be labeled as Use_In_Analysis = TRUE. Any that fail either test will be excluded from the analyses and labeled as Use_In_Analysis = FALSE. The points for all Water Column plots displayed in this section are monthly averages. Trend significance will be denoted as “Significant Trend” (when p < 0.05), or “Non-significant Trend” (when p >= 0.05). Any parameters with insufficient data to perform Seasonal Kendall-Tau test will have their monthly averages plotted without a corresponding trend line.

Water Quality - Discrete

The following files were used in the discrete analysis:

  • Combined_WQ_WC_NUT_Chlorophyll_a_corrected_for_pheophytin-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Chlorophyll_a_uncorrected_for_pheophytin-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Colored_dissolved_organic_matter_CDOM-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Dissolved_Oxygen-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Dissolved_Oxygen_Saturation-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_pH-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Salinity-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Secchi_Depth-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Total_Nitrogen-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Total_Phosphorus-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Total_Suspended_Solids_TSS-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Turbidity-2025-Sep-04.txt

  • Combined_WQ_WC_NUT_Water_Temperature-2025-Sep-04.txt

Chlorophyll a, Corrected for Pheophytin - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average levels of chlorophyll a, corrected for pheophytin, over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed chlorophyll a (triangles) is included in the plot.
Scatter plot of monthly average levels of chlorophyll a, corrected for pheophytin, over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed chlorophyll a (triangles) is included in the plot.
Seasonal Kendall-Tau Trend Analysis for Chlorophyll a, Corrected for Pheophytin
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Lab Significantly increasing trend 1703 24 2002 - 2025 5.5 0.4277 1.8595 0.3791 0

Monthly average chlorophyll a, corrected for pheophytin, increased by 0.38 µg/L per year, indicating a decrease in water clarity.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Chlorophyll a, Corrected for Pheophytin
ProgramID N_Data YearMin YearMax
4054 726 2002 2025
5014 630 2017 2024
5002 373 2002 2024

Program names:

4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Chlorophyll a, Uncorrected for Pheophytin - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average levels of chlorophyll a, uncorrected for pheophytin, over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed chlorophyll a (triangles) is included in the plot.
Scatter plot of monthly average levels of chlorophyll a, uncorrected for pheophytin, over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed chlorophyll a (triangles) is included in the plot.
Seasonal Kendall-Tau Trend Analysis for Chlorophyll a, Uncorrected for Pheophytin
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Lab Significantly increasing trend 1342 24 2002 - 2025 7.8 0.4041 2.0884 0.4232 0

Monthly average chlorophyll a, uncorrected for pheophytin, increased by 0.42 µg/L per year, indicating a decrease in water clarity.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Chlorophyll a, Uncorrected for Pheophytin
ProgramID N_Data YearMin YearMax
5014 678 2017 2024
4054 604 2002 2025
5002 139 2019 2024
118 1 2006 2006
95 1 2012 2012

Program names:

95 - Harmful Algal Bloom Marine Observation Network4
118 - National Aquatic Resource Surveys, National Coastal Condition Assessment5
4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Colored Dissolved Organic Matter - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average colored dissolved organic matter (CDOM) over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed CDOM (triangles) is included in the plot.
Scatter plot of monthly average colored dissolved organic matter (CDOM) over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only laboratory-analyzed CDOM (triangles) is included in the plot.
Seasonal Kendall-Tau Trend Analysis for Colored Dissolved Organic Matter
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Lab No significant trend 261 13 2007 - 2025 19.7238 0.0318 20.0715 0.105 0.6375

Colored dissolved organic matter showed no detectable trend between 2007 and 2025.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Colored Dissolved Organic Matter
ProgramID N_Data YearMin YearMax
4054 194 2007 2025
5002 62 2020 2024
5014 7 2018 2018

Program names:

4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Dissolved Oxygen - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average dissolved oxygen over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only dissolved oxygen values measured in the field (circles) are included in the plot.
Scatter plot of monthly average dissolved oxygen over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only dissolved oxygen values measured in the field (circles) are included in the plot.
Seasonal Kendall-Tau Trend Analysis for Dissolved Oxygen
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Field Significantly decreasing trend 7664 31 1995 - 2025 5.7 -0.0793 5.9243 -0.0129 0.0355

Monthly average dissolved oxygen decreased by 0.01 mg/L per year.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Dissolved Oxygen
ProgramID N_Data YearMin YearMax
5002 6651 1995 2024
4054 522 2002 2025
5014 295 2017 2024
69 150 2001 2010
95 130 2007 2018
118 1 2006 2006

Program names:

69 - Fisheries-Independent Monitoring (FIM) Program6
95 - Harmful Algal Bloom Marine Observation Network4
118 - National Aquatic Resource Surveys, National Coastal Condition Assessment5
4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Dissolved Oxygen Saturation - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average dissolved oxygen saturation over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only dissolved oxygen saturation values measured in the field (circles) are included in the plot.
Scatter plot of monthly average dissolved oxygen saturation over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only dissolved oxygen saturation values measured in the field (circles) are included in the plot.
Seasonal Kendall-Tau Trend Analysis for Dissolved Oxygen Saturation
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Field Significantly increasing trend 1207 22 1999 - 2024 78.9 0.144 74.4282 0.2875 0.0057

Monthly average dissolved oxygen saturation increased by 0.29% per year.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Dissolved Oxygen Saturation
ProgramID N_Data YearMin YearMax
5002 1002 1999 2024
5014 220 2017 2022
95 3 2012 2013

Program names:

95 - Harmful Algal Bloom Marine Observation Network4
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

pH - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average pH over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only pH values measured in the field (circles) are included in the plot.
Scatter plot of monthly average pH over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only pH values measured in the field (circles) are included in the plot.
Seasonal Kendall-Tau Trend Analysis for pH
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Field Significantly decreasing trend 6239 31 1995 - 2025 7.7 -0.1104 7.6749 -0.0035 0.0027

Monthly average pH decreased by less than 0.01 pH units per year.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for pH
ProgramID N_Data YearMin YearMax
5002 5495 1995 2024
4054 523 2002 2025
5014 299 2017 2024
69 153 2001 2010
95 99 2007 2018

Program names:

69 - Fisheries-Independent Monitoring (FIM) Program6
95 - Harmful Algal Bloom Marine Observation Network4
4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Salinity - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average salinity over time. If the time series included ten or more years of discrete observations, significant (blue) or non-significant (magenta) trend lines are also shown. Discrete salinity values derived from grab samples analyzed in the field (circles) or the laboratory (triangles) are both included in the plot.
Scatter plot of monthly average salinity over time. If the time series included ten or more years of discrete observations, significant (blue) or non-significant (magenta) trend lines are also shown. Discrete salinity values derived from grab samples analyzed in the field (circles) or the laboratory (triangles) are both included in the plot.
Seasonal Kendall-Tau Trend Analysis for Salinity
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
All Significantly decreasing trend 8469 31 1995 - 2025 30.9 -0.1921 31.6867 -0.1891 0

Monthly average salinity decreased by 0.19 ppt per year.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Salinity
ProgramID N_Data YearMin YearMax
5002 7388 1995 2024
4054 419 2002 2025
5014 299 2017 2024
95 236 1999 2018
69 153 2001 2010

Program names:

69 - Fisheries-Independent Monitoring (FIM) Program6
95 - Harmful Algal Bloom Marine Observation Network4
4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Secchi Depth - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average Secchi depth over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Secchi depth is only measured in the field (circles).
Scatter plot of monthly average Secchi depth over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Secchi depth is only measured in the field (circles).
Seasonal Kendall-Tau Trend Analysis for Secchi Depth
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Field No significant trend 1406 23 1999 - 2024 -0.7 0.0703 -0.8099 0.003 0.1749

Secchi depth showed no detectable trend between 1999 and 2024.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Secchi Depth
ProgramID N_Data YearMin YearMax
5002 749 1999 2024
5014 269 2017 2024
4054 236 2002 2014
69 153 2001 2010

Program names:

69 - Fisheries-Independent Monitoring (FIM) Program6
4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Total Nitrogen - Discrete

Total Nitrogen Calculation:

The logic for calculated Total Nitrogen was provided by Kevin O’Donnell and colleagues at FDEP (with the help of Jay Silvanima, Watershed Monitoring Section). The following logic is used, in this order, based on the availability of specific nitrogen components.

  1. TN = TKN + NO3O2;
  2. TN = TKN + NO3 + NO2;
  3. TN = ORGN + NH4 + NO3O2;
  4. TN = ORGN + NH4 + NO2 + NO3;
  5. TN = TKN + NO3;
  6. TN = ORGN + NH4 + NO3;

Additional Information:

  • Rules for use of sample fraction:
    • Florida Department of Environmental Protection (FDEP) report that if both “Total” and “Dissolved” components are reported, only “Total” is used. If the total is not reported, then the dissolved components are used as a best available replacement.
    • Total nitrogen calculations are done using nitrogen components with the same sample fraction, nitrogen components with mixed total/dissolved sample fractions are not used. In other words, total nitrogen can be calculated when TKN and NO3O2 are both total sample fractions, or when both are dissolved sample fractions. Future calculations of total nitrogen values may be based on components with mixed sample fractions.
  • Values inserted into data:
    • ParameterName = “Total Nitrogen”
    • SEACAR_QAQCFlagCode = “1Q”
    • SEACAR_QAQC_Description = “SEACAR Calculated”

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average total nitrogen over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only nitrogen values obtained from laboratory analyses (triangles) are included in the plot.
Scatter plot of monthly average total nitrogen over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only nitrogen values obtained from laboratory analyses (triangles) are included in the plot.
Seasonal Kendall-Tau Trend Analysis for Total Nitrogen
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Lab No significant trend 2045 29 1997 - 2025 0.61 0.0244 0.5594 0.0013 0.5273

Total nitrogen showed no detectable trend between 1997 and 2025.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Total Nitrogen
ProgramID N_Data YearMin YearMax
5002 1171 1997 2024
5014 477 2017 2022
4054 422 2002 2025

Program names:

4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Total Phosphorus - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average total phosphorus over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only phosphorus values obtained from laboratory analyses (triangles) are included in the plot.
Scatter plot of monthly average total phosphorus over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only phosphorus values obtained from laboratory analyses (triangles) are included in the plot.
Seasonal Kendall-Tau Trend Analysis for Total Phosphorus
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Lab Significantly decreasing trend 2959 29 1997 - 2025 0.0751 -0.2104 0.0986 -0.001 0

Monthly average total phosphorus decreased by less than 0.01 mg/L per year.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Total Phosphorus
ProgramID N_Data YearMin YearMax
5002 1795 1997 2024
5014 631 2017 2024
4054 596 2002 2025

Program names:

4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Total Suspended Solids - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average total suspended solids (TSS) over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only TSS values obtained from laboratory analyses (triangles) are included in the plot.
Scatter plot of monthly average total suspended solids (TSS) over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only TSS values obtained from laboratory analyses (triangles) are included in the plot.
Seasonal Kendall-Tau Trend Analysis for Total Suspended Solids
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Lab Significantly decreasing trend 1732 29 1997 - 2025 22.4 -0.3289 31.4295 -0.619 0

Monthly average total suspended solids decreased by 0.62 mg/L per year, indicating an increase in water clarity.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Total Suspended Solids
ProgramID N_Data YearMin YearMax
5002 1384 1997 2024
4054 584 2002 2025
5014 126 2018 2022

Program names:

4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Turbidity - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average turbidity over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only turbidity values measured in the laboratory (triangles) are included in the plot.
Scatter plot of monthly average turbidity over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only turbidity values measured in the laboratory (triangles) are included in the plot.
Seasonal Kendall-Tau Trend Analysis for Turbidity
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Lab Significantly increasing trend 5026 30 1995 - 2024 5.2 0.211 6.0441 0.0989 0

Monthly average turbidity increased by 0.1 NTU per year, indicating a decrease in water clarity.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Turbidity
ProgramID N_Data YearMin YearMax
5002 4894 1995 2024
4054 288 2002 2021
5014 126 2018 2022
95 4 2012 2012

Program names:

95 - Harmful Algal Bloom Marine Observation Network4
4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Water Temperature - Discrete

Seasonal Kendall-Tau Trend Analysis

Scatter plot of monthly average water temperature over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only water temperature measurements taken in the field (circles) are included in the plot.
Scatter plot of monthly average water temperature over time. If the time series included ten or more years of discrete observations, a significant (blue) or non-significant (magenta) trend line is also shown. Only water temperature measurements taken in the field (circles) are included in the plot.
Seasonal Kendall-Tau Trend Analysis for Water Temperature
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
Field Significantly increasing trend 8376 31 1995 - 2025 23.1 0.1249 22.7604 0.0329 0.0007

Monthly average water temperature increased by 0.03°C per year.

Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of discrete water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Programs contributing data for Water Temperature
ProgramID N_Data YearMin YearMax
5002 7598 1995 2024
4054 533 2002 2025
5014 299 2017 2024
95 228 2007 2018
69 153 2001 2010

Program names:

69 - Fisheries-Independent Monitoring (FIM) Program6
95 - Harmful Algal Bloom Marine Observation Network4
4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5002 - Florida STORET / WIN2
5014 - Guana River and Guana Lake Water Quality Monitoring3

Water Quality - Continuous

The following files were used in the continuous analysis:

  • Combined_WQ_WC_NUT_cont_Dissolved_Oxygen_NE-2025-Sep-19.txt

  • Combined_WQ_WC_NUT_cont_Dissolved_Oxygen_Saturation_NE-2025-Sep-19.txt

  • Combined_WQ_WC_NUT_cont_pH_NE-2025-Sep-19.txt

  • Combined_WQ_WC_NUT_cont_Salinity_NE-2025-Sep-19.txt

  • Combined_WQ_WC_NUT_cont_Turbidity_NE-2025-Sep-19.txt

  • Combined_WQ_WC_NUT_cont_Water_Temperature_NE-2025-Sep-19.txt

Continuous monitoring locations in Guana River Marsh Aquatic Preserve

Station overview for Continuous parameters by Program
ProgramID ProgramLocationID Years of Data Use in Analysis Parameters
4054 gtmpiwq 25 TRUE DO , DOS , pH , Sal , Turb , TempW
5062 872-0494 2 FALSE Sal , TempW

Program names:

4054 - Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program1
5062 - FDEP Bureau of Survey and Mapping Continuous Water Quality Program7

Map showing continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. Sites marked as Use In Analysis (green) are featured in this report.
Map showing continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. Sites marked as Use In Analysis (green) are featured in this report.

Dissolved Oxygen - Continuous

Scatter plot of monthly average dissolved oxygen over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average dissolved oxygen over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results for Dissolved Oxygen - All Stations
Station Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
gtmpiwq Significantly decreasing trend 685087 25 2001 - 2025 5.8 -0.09 5.78 -0.01 0.04

At one program location, monthly average dissolved oxygen decreased by 0.01 mg/L per year.

Map showing location of dissolved oxygen continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of dissolved oxygen continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Dissolved Oxygen Saturation - Continuous

Scatter plot of monthly average dissolved oxygen saturation over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average dissolved oxygen saturation over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results for Dissolved Oxygen Saturation - All Stations
Station Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
gtmpiwq Significantly decreasing trend 690905 25 2001 - 2025 82.2 -0.17 81.97 -0.16 0

At one program location, monthly average dissolved oxygen saturation decreased by 0.16% per year.

Map showing location of dissolved oxygen saturation continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of dissolved oxygen saturation continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

pH - Continuous

Scatter plot of monthly average pH over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average pH over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results for pH - All Stations
Station Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
gtmpiwq Significantly decreasing trend 682135 25 2001 - 2025 7.6 -0.17 7.61 0 0

At one program location, monthly average pH decreased by less than 0.01 pH units per year.

Map showing location of ph continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of ph continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Salinity - Continuous

Scatter plot of monthly average salinity over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average salinity over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results for Salinity - All Stations
Station Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
gtmpiwq Significantly decreasing trend 689204 25 2001 - 2025 27.90 -0.26 32.47 -0.31 0
872-0494 Insufficient data to calculate trend 34918 2 2020 - 2021 8.99 - - - -

At one program location, monthly average salinity decreased by 0.31 ppt per year. There was insufficient data to fit a model for one location.

Map showing location of salinity continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of salinity continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Turbidity - Continuous

Scatter plot of monthly average turbidity over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average turbidity over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results for Turbidity - All Stations
Station Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
gtmpiwq Significantly decreasing trend 665212 25 2001 - 2025 10 -0.1 14.7 -0.08 0.01

At one program location, monthly average turbidity decreased by 0.08 NTU per year.

Map showing location of turbidity continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of turbidity continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Water Temperature - Continuous

Scatter plot of monthly average water temperature over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Scatter plot of monthly average water temperature over time at continuously monitored program locations. Each location is analyzed separately, with significant (blue) or non-significant (magenta) trend lines shown for time series that included five or more years of observations.
Seasonal Kendall-Tau Results for Water Temperature - All Stations
Station Statistical Trend Sample Count Years with Data Period of Record Median tau Sen Intercept Sen Slope p
gtmpiwq Significantly increasing trend 739497 25 2001 - 2025 24.30 0.2 23.53 0.04 0
872-0494 Insufficient data to calculate trend 35473 2 2020 - 2021 22.34 - - - -

At one program location, monthly average water temperature increased by 0.04°C per year. There was insufficient data to fit a model for one location.

Map showing location of water temperature continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of water temperature continuous water quality sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Coastal Wetlands

The data file used is: All_CW_Parameters-2025-Sep-04.txt

Line graph of annual average coastal wetlands species richness over time for mangroves and associates (triangles), marsh (squares), and marsh succulents (circles). If the time series by species group included more than one year of observations, a line connects data points for visualization.
Line graph of annual average coastal wetlands species richness over time for mangroves and associates (triangles), marsh (squares), and marsh succulents (circles). If the time series by species group included more than one year of observations, a line connects data points for visualization.
Coastal Wetlands Species Richness
Species Group Sample Count Number of Years Period of Record Median N of Taxa Mean N of Taxa
Marsh 795 12 2012 - 2023 1 1.0
Marsh succulents 58 12 2012 - 2023 1 1.1

Between 2012 and 2023, the median annual number of species for marsh was 1 based on 795 observations. Between 2012 and 2023, the median annual number of species for marsh succulents was 1 based on 58 observations.

Map showing location of coastal wetlands sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of coastal wetlands sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Oyster

The data file used is: All_OYSTER_Parameters-2025-Sep-04.txt

Density

Natural

Scatter plot of oyster density over time. If the time series included five or more years with observations, an estimated trend (blue line) and a 95% credible interval (purple band) may also be plotted. Data points are jittered horizontally to reduce overlap.
Scatter plot of oyster density over time. If the time series included five or more years with observations, an estimated trend (blue line) and a 95% credible interval (purple band) may also be plotted. Data points are jittered horizontally to reduce overlap.
Model results for Oyster Density - Natural
Shell Type Habitat Type Trend Status Estimate Standard Error Credible Interval
Live Oysters Natural Significantly decreasing trend -74.15 362.85 -27.5 to -207.29

For natural reefs, density decreased by an average of 75.9 oysters per square meter per year.

Map showing location of oyster density sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of oyster density sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Percent Live

Natural

Scatter plot of percent live oysters over time. If the time series included five or more years with observations, an estimated trend (blue line) and a 95% credible interval (purple band) may also be plotted. Data points are jittered horizontally to reduce overlap.
Scatter plot of percent live oysters over time. If the time series included five or more years with observations, an estimated trend (blue line) and a 95% credible interval (purple band) may also be plotted. Data points are jittered horizontally to reduce overlap.
Model results for Oyster Percent Live - Natural
Shell Type Habitat Type Trend Status Estimate Standard Error Credible Interval
Live Oysters Natural Significantly increasing trend 0.04 9.65 0.02 to 0.08

For natural reefs, percent live cover increased by an average of 0.05% per year.

Map showing location of oyster percent live sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of oyster percent live sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Shell Height

Natural

Model results for Oyster Shell Height - Natural
Shell Type SizeClass Habitat Type Trend Status Estimate Standard Error Credible Interval
Dead Oyster Shells Natural - - - -
Dead Oyster Shells >75mm Natural - - - -
Dead Oyster Shells 25-75mm Natural - - - -
Live Oysters Natural - - - -
Live Oysters >75mm Natural No significant change 0.29 0.46 -0.66 to 1.18
Live Oysters 25-75mm Natural No significant change 0.69 0.35 0 to 1.4

For natural reefs, annual average live oyster shell height in the 25-75mm and ≥75mm size classes increased by 0.69 mm per year and 0.29 mm per year, respectively. Models are not run on dead oyster shell measurements.

Map showing location of oyster shell height sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of oyster shell height sampling locations within the boundaries of Guana River Marsh Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Species list

Avicennia germinans1 Hypericum sp. Salicornia ambigua1
Bare substrate Ilex vomitoria Smilax bona-nox
Batis maritima1 Iva frutescens Spartina alterniflora1
Coleataenia anceps Juncus roemerianus1 Vitis sp.
Dichanthelium sp. Quercus virginiana Woody debris
Distichlis spicata1 Sabal palmetto Avicennia germinans1

1 - Coastal Wetlands

References

1.
Florida Department of Environmental Protection (DEP); Office of Resilience and Coastal Protection (RCP); Guana Tolomato Matanzas National Estuarine Research Reserve (GTMNERR); NOAA National Estuarine Research Reserve System (NERRS). Guana Tolomato Matanzas National Estuarine Research Reserve System-Wide Monitoring Program. (2024).
2.
Florida Department of Environmental Protection (DEP). Florida STORET / WIN. (2024).
3.
Florida Department of Environmental Protection (DEP); Office of Resilience and Coastal Protection (RCP); Guana Tolomato Matanzas National Estuarine Research Reserve (GTMNERR); Friends of GTM; Florida Fish and Wildlife Conservation Commission (FWC). Guana River and Guana Lake Water Quality Monitoring . (2024).
4.
Florida Fish and Wildlife Conservation Commission (FWC); Florida Fish and Wildlife Research Institute (FWRI). Harmful Algal Bloom Marine Observation Network. (2018).
5.
U.S. Environmental Protection Agency (EPA); Office of Water; National Oceanic and Atmospheric Administration (NOAA); U.S. Geological Survey (USGS); U.S. Fish and Wildlife Service (USFWS); National Estuary Program (NEP); coastal states. National Aquatic Resource Surveys, National Coastal Condition Assessment. (2021).
6.
Florida Fish and Wildlife Conservation Commission (FWC). Fisheries-Independent Monitoring (FIM) Program. (2022).
7.
Florida Department of Environmental Protection (DEP); Division of State Lands; Bureau of Survey and Mapping. FDEP Bureau of Survey and Mapping Continuous Water Quality Program. (2021).