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.
Table:

Total nitrogen showed no detectable trend between 1997 and 2025.

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab No detectable trend 1114 27 1997 - 2025 0.41405 0.02443 0.37083 0.00098 0.6327
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

Total phosphorus showed no detectable trend between 1997 and 2025.

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab No detectable trend 1676 27 1997 - 2025 0.06625 0.01212 0.06554 0.00009 0.7119
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Water Quality

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.
Table:

At one program location, monthly average dissolved oxygen decreased by 0.11 mg/L per year. No detectable change in monthly average dissolved oxygen was observed at four locations. There was insufficient data to fit a model for four locations.

Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
02231291 Insufficient data 689 3 2014 - 2016 5.70 - - - -
NECI Insufficient data 77240 4 2023 - 2026 6.20 - - - -
NEHM No detectable trend 127898 5 2022 - 2026 5.70 0.22 5.36 0.09 0.14
NEKD No detectable trend 110958 8 2004 - 2011 6.40 -0.04 6.59 -0.02 0.56
NELC Decreasing trend 95860 7 2005 - 2011 5.60 -0.34 5.93 -0.11 0
NENR Insufficient data 31438 3 2009 - 2011 5.80 - - - -
NCB19020038 No detectable trend 34476 5 2015 - 2019 6.16 -0.03 6.23 -0.03 0.61
NCBARD16 Insufficient data 7417 2 2015 - 2016 5.08 - - - -
NCBNRCM No detectable trend 35477 5 2015 - 2019 5.79 0.05 5.78 0.01 0.8
Map showing location of dissolved oxygen continuous water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

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.
Table:

Monthly average dissolved oxygen decreased by 0.04 mg/L per year.

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field Decreasing trend 22738 31 1995 - 2026 6.8 -0.27173 7.32517 -0.03647 0
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

At one program location, monthly average dissolved oxygen saturation decreased by 1.60% per year. No detectable change in monthly average dissolved oxygen saturation was observed at four locations. There was insufficient data to fit a model for three locations.

Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
NECI Insufficient data 77587 4 2023 - 2026 82.50 - - - -
NEHM No detectable trend 130580 5 2022 - 2026 72.90 0.19 69.88 1.7 0.2
NEKD No detectable trend 110983 8 2004 - 2011 89.10 0 87.49 -0.04 0.93
NELC Decreasing trend 95868 7 2005 - 2011 77.90 -0.27 78.93 -1.6 0.01
NENR Insufficient data 31438 3 2009 - 2011 73.20 - - - -
NCB19020038 No detectable trend 34438 5 2015 - 2019 87.06 -0.16 86.02 -0.6 0.13
NCBARD16 Insufficient data 7417 2 2015 - 2016 74.44 - - - -
NCBNRCM No detectable trend 35240 5 2015 - 2019 82.06 -0.05 81.1 -0.14 0.8
Map showing location of dissolved oxygen saturation continuous water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

Dissolved oxygen saturation showed no detectable trend between 2000 and 2026.

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field No detectable trend 1521 21 2000 - 2026 88 -0.07841 89.70324 -0.08082 0.1518
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

Salinity showed no detectable trend between 1980 and 2026.

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
All No detectable trend 22844 31 1980 - 2026 30.5 -0.04983 30.32475 -0.04363 0.1904
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

At one program location, monthly average salinity increased by 0.52 ppt per year. No detectable change in monthly average salinity was observed at four locations. There was insufficient data to fit a model for three locations.

Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
NECI Insufficient data 76803 4 2023 - 2026 30.80 - - - -
NEHM No detectable trend 129295 5 2022 - 2026 15.60 0.04 14.45 0.51 0.84
NEKD Increasing trend 118328 8 2004 - 2011 33.20 0.31 30.29 0.52 0
NELC No detectable trend 100339 7 2005 - 2011 27.90 0.09 25.3 0.53 0.44
NENR Insufficient data 31438 3 2009 - 2011 12.40 - - - -
NCB19020038 No detectable trend 34438 5 2015 - 2019 31.75 -0.06 31.07 -0.11 1
NCBARD16 Insufficient data 7418 2 2015 - 2016 30.07 - - - -
NCBNRCM No detectable trend 35411 5 2015 - 2019 30.29 -0.12 30.26 -0.39 0.55
Map showing location of salinity continuous water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

No detectable change in monthly average water temperature was observed at five locations. There was insufficient data to fit a model for four locations.

Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
02231291 Insufficient data 710 3 2014 - 2016 23.50 - - - -
NECI Insufficient data 80058 4 2023 - 2026 20.70 - - - -
NEHM No detectable trend 135834 5 2022 - 2026 23.20 0.08 22.33 0.17 0.62
NEKD No detectable trend 118328 8 2004 - 2011 22.10 -0.04 21.88 -0.01 0.81
NELC No detectable trend 100343 7 2005 - 2011 22.70 0.05 22.26 0.04 0.74
NENR Insufficient data 31438 3 2009 - 2011 22.00 - - - -
NCB19020038 No detectable trend 34483 5 2015 - 2019 24.78 -0.03 23.32 -0.01 1
NCBARD16 Insufficient data 7419 2 2015 - 2016 25.08 - - - -
NCBNRCM No detectable trend 35817 5 2015 - 2019 24.03 0.07 23.26 0.05 0.67
Map showing location of water temperature continuous water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

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

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field Increasing trend 22906 31 1995 - 2026 23 0.12295 22.26829 0.03339 0.0022
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

At one program location, monthly average pH increased by 0.01 pH units per year. No detectable change in monthly average pH was observed at four locations. There was insufficient data to fit a model for three locations.

Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
NECI Insufficient data 77746 4 2023 - 2026 7.70 - - - -
NEHM No detectable trend 133897 5 2022 - 2026 7.10 0.22 7.03 0.03 0.14
NEKD Increasing trend 113471 8 2004 - 2011 7.90 0.19 7.87 0.01 0.05
NELC No detectable trend 96488 7 2005 - 2011 7.50 0.02 7.51 0 0.91
NENR Insufficient data 31438 3 2009 - 2011 7.10 - - - -
NCB19020038 No detectable trend 34405 5 2015 - 2019 7.88 -0.01 7.85 0 1
NCBARD16 Insufficient data 6952 2 2015 - 2016 7.66 - - - -
NCBNRCM No detectable trend 35819 5 2015 - 2019 7.72 -0.01 7.69 0 0.93
Map showing location of ph continuous water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

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

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field Decreasing trend 22671 31 1995 - 2026 7.6 -0.12673 7.72273 -0.00429 0.0014
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Specific Conductivity - Continuous

Scatter plot of monthly average specific conductivity 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 specific conductivity 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.
Table:

At one program location, monthly average specific conductivity increased by 0.71 mS/cm per year. No detectable change in monthly average specific conductivity was observed at four locations. There was insufficient data to fit a model for four locations.

Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
02231291 Insufficient data 682 3 2014 - 2016 30.40 - - - -
NECI Insufficient data 76803 4 2023 - 2026 47.29 - - - -
NEHM No detectable trend 129299 5 2022 - 2026 25.56 0.04 23.65 0.73 0.84
NEKD Increasing trend 118327 8 2004 - 2011 50.62 0.31 46.46 0.71 0
NELC No detectable trend 100339 7 2005 - 2011 43.33 0.08 39.43 0.77 0.51
NENR Insufficient data 31438 3 2009 - 2011 20.04 - - - -
NCB19020038 No detectable trend 34438 5 2015 - 2019 48.67 -0.06 47.75 -0.15 1
NCBARD16 Insufficient data 7418 2 2015 - 2016 46.32 - - - -
NCBNRCM No detectable trend 35411 5 2015 - 2019 46.65 -0.12 46.58 -0.54 0.55
Map showing location of specific conductivity continuous water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.
Map showing location of specific conductivity continuous water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

Water Clarity

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.
Table:

At one program location, monthly average turbidity increased by 0.60 NTU per year. No detectable change in monthly average turbidity was observed at four locations. There was insufficient data to fit a model for three locations.

Program Location Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
NECI Insufficient data 66966 4 2023 - 2026 14.00 - - - -
NEHM Increasing trend 123949 5 2022 - 2026 12.00 0.36 12.18 0.6 0.01
NEKD No detectable trend 114181 8 2004 - 2011 4.00 0.02 6.06 0.05 0.87
NELC No detectable trend 96153 7 2005 - 2011 15.00 0.16 15.18 0.64 0.15
NENR Insufficient data 31087 3 2009 - 2011 21.00 - - - -
NCB19020038 No detectable trend 31407 5 2015 - 2019 5.77 -0.01 6.79 0.12 0.79
NCBARD16 Insufficient data 7385 2 2015 - 2016 12.89 - - - -
NCBNRCM No detectable trend 34696 5 2015 - 2019 8.64 -0.1 10.09 -0.14 0.6
Map showing location of turbidity continuous water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.

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.
Table:

Monthly average turbidity increased by 0.12 NTU per year, indicating a decrease in water clarity.

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab Increasing trend 1135 27 1997 - 2025 7.1 0.17024 4.40949 0.12225 0.0002
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

Total suspended solids showed no detectable trend between 1997 and 2025.

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab No detectable trend 965 26 1997 - 2025 18 0.0678 17.34193 0.1392 0.1502
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

Chlorophyll a, uncorrected for pheophytin, showed no detectable trend between 2004 and 2025.

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab No detectable trend 405 14 2004 - 2025 6.8 -0.10118 9.14587 -0.05758 0.513
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

Chlorophyll a, corrected for pheophytin, showed no detectable trend between 2001 and 2025.

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Lab No detectable trend 756 19 2001 - 2025 5.7 0.10262 4.47525 0.06721 0.1212
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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).
Table:

Secchi depth showed no detectable trend between 2000 and 2025.

Activity Type Statistical Trend Sample Count Years with Data Period of Record Median Result Value Tau Sen Intercept Sen Slope P
Field No detectable trend 20451 26 2000 - 2025 -0.7 0.06628 -0.78549 0.00195 0.1168
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes 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.
Table:

There was insufficient data to fit a model 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 Insufficient data 588 6 2020 - 2025 24.53637 - - - -
Map showing location of discrete water quality sampling locations within the boundaries of Nassau River-St. Johns River Marshes 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 Nassau River-St. Johns River Marshes Aquatic Preserve. The bubble size on the maps above reflect the amount of data available at each sampling site.