Indicators

Nutrients

Total Nitrogen - Discrete

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 Results for - Total Nitrogen
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab Significantly increasing trend 9152 33 1993 - 2025 0.673 0.11018 0.59816 0.00345 0.0037

Monthly average total nitrogen increased by less than 0.01 mg/L per year.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Total Phosphorus - Discrete

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 Results for - Total Phosphorus
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab No significant trend 7044 28 1998 - 2025 0.114 0.06013 0.11264 0.00047 0.1351

Total phosphorus showed no detectable trend between 1998 and 2025.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Water Quality

Dissolved Oxygen - Discrete

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 Results for - Dissolved Oxygen
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field Significantly decreasing trend 72673 38 1971 - 2025 6.5 -0.13554 6.90197 -0.01054 1e-04

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 Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

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 - Dissolved Oxygen
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
CHEW1 Insufficient data to calculate trend 39706 2 2024 - 2025 6.4 - - - -

There was insufficient data to fit a model for one location.

Map showing location of dissolved oxygen continuous water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Dissolved Oxygen Saturation - Discrete

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 Results for - Dissolved Oxygen Saturation
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field Significantly increasing trend 930 16 1992 - 2025 86.1 0.37078 22.75463 2.10989 0

Monthly average dissolved oxygen saturation increased by 2.11% per year.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor 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 - Dissolved Oxygen Saturation
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
CHEW1 Insufficient data to calculate trend 39704 2 2024 - 2025 89.9 - - - -

There was insufficient data to fit a model for one location.

Map showing location of dissolved oxygen saturation continuous water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Salinity - Discrete

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 Results for - Salinity
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
All Significantly decreasing trend 76014 50 1954 - 2025 26.635 -0.27536 32.9701 -0.11128 0

Monthly average salinity decreased by 0.11 ppt per year.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor 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 - Salinity
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
02293254 Insufficient data to calculate trend 1030 4 2011 - 2014 29.0 - - - -
02293252 Insufficient data to calculate trend 1002 4 2011 - 2014 30.0 - - - -
CHEW1 Insufficient data to calculate trend 48346 2 2024 - 2025 27.5 - - - -

There was insufficient data to fit a model for three locations.

Map showing location of salinity continuous water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Water Temperature - Discrete

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 Results for - Water Temperature
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field Significantly increasing trend 73705 50 1954 - 2025 26.1 0.14365 24.68864 0.01602 0

Monthly average water temperature increased by 0.02°C per year.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor 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 - Water Temperature
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
02293254 Insufficient data to calculate trend 1041 4 2011 - 2014 27.0 - - - -
02293252 Insufficient data to calculate trend 1003 4 2011 - 2014 26.4 - - - -
CHEW1 Insufficient data to calculate trend 48352 2 2024 - 2025 26.7 - - - -

There was insufficient data to fit a model for three locations.

Map showing location of water temperature continuous water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

pH - Discrete

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 Results for - pH
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field No significant trend 69372 38 1955 - 2025 7.9 0.01999 7.87931 0.00023 0.5775

pH showed no detectable trend between 1955 and 2025.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor 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 - pH
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
CHEW1 Insufficient data to calculate trend 44990 2 2024 - 2025 7.9 - - - -

There was insufficient data to fit a model for one location.

Map showing location of ph continuous water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Water Clarity

Turbidity - Discrete

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 Results for - Turbidity
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab Significantly decreasing trend 12973 31 1995 - 2025 1.9 -0.19665 2.69147 -0.02782 0

Monthly average turbidity decreased by 0.03 NTU per year, indicating an increase in water clarity.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor 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 - Turbidity
Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
CHEW1 Insufficient data to calculate trend 33403 2 2024 - 2025 2 - - - -

There was insufficient data to fit a model for one location.

Map showing location of turbidity continuous water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Total Suspended Solids - Discrete

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 Results for - Total Suspended Solids
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab No significant trend 7310 30 1996 - 2025 7.75 0.04957 8.58862 0.04122 0.1997

Total suspended solids showed no detectable trend between 1996 and 2025.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Chlorophyll a, Uncorrected for Pheophytin - Discrete

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 Results for - Chlorophyll a, Uncorrected for Pheophytin
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab Significantly decreasing trend 2469 29 1997 - 2025 4.81 -0.1221 6.77682 -0.05932 0.0074

Monthly average chlorophyll a, uncorrected for pheophytin, decreased by 0.06 µg/L per year, indicating an increase in water clarity.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Chlorophyll a, Corrected for Pheophytin - Discrete

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 Results for - Chlorophyll a, Corrected for Pheophytin
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab Significantly decreasing trend 2889 21 2001 - 2025 3.14 -0.18214 6.34053 -0.12751 2e-04

Monthly average chlorophyll a, corrected for pheophytin, decreased by 0.13 µg/L per year, indicating an increase in water clarity.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Secchi Depth - Discrete

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 Results for - Secchi Depth
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field No significant trend 45800 32 1994 - 2025 -1.2 -0.0458 -1.35283 -0.00275 0.2074

Secchi depth showed no detectable trend between 1994 and 2025.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Colored Dissolved Organic Matter - Discrete

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 Results for - Colored Dissolved Organic Matter
Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab No significant trend 1201 17 2001 - 2025 11.7 -0.07404 16.58418 -0.22484 0.099

Colored dissolved organic matter showed no detectable trend between 2001 and 2025.

Map showing location of discrete water quality sampling locations within the boundaries of Gasparilla Sound-Charlotte Harbor 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 Gasparilla Sound-Charlotte Harbor Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.