Hudson Bayou Condition Report for 2012

Caution
Rating icon - Chlorophyll a Rating icon - Total Nitrogen Rating icon - Total Phosphorous Rating icon - Dissolved Oxygen Saturation

2 out of 4 indicators were rated as PASS.

All four indicators must pass for the creek to be rated as PASS.

Learn more about how this report is created

  • Size: 2,406 acres
  • Location: North Sarasota County
  • Discharges into: Sarasota Bay

For more information, please see: Sarasota Bay Water Quality Management Plan (2012)

View county-wide water quality trends »

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Hudson Bayou

Hudson Bayou
Visit the Hudson Bayou water resource page »

Water Chemistry Ratings | Freshwater Portion of the Creek

Creek Conditions Ratings are based on comparing nitrogen, phosphorus, chlorophyll and dissolved oxygen to water quality guidelines or regulations. Florida law defines a maximum allowable concentration of nitrogen, phosphorus, and chlorophyll a, and a minimum allowable concentration of dissolved oxygen in these streams. Learn more about these ratings and how they are calculated »

Data for the following WBIDs is averaged when compiling the data below:
  • 1953A
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Pass

Chlorophyll a

Score: Pass
Units: mg/L Year
2012		 Historical
period of record
High 0.1568 0.1568
Mean 0.0014 0.0015 0.01583655
Low 0.0003 0.0003
No. of Samples 72 301

Five-year Rolling Average

  • Annual Mean
Pass

Nitrogen, Total

Score: Pass
Units: mg/L Year
2012		 Historical
period of record
High 1.866 1.866
Mean 0.9244 0.821 0.30305973
Low 0.549 0.082
No. of Samples 24 161

Five-year Rolling Average

  • Annual Mean
Pass

Phosphorus, Total

Score: Pass
Units: mg/L Year
2012		 Historical
period of record
High 1.41 4.05
Mean 0.487 0.4769 0.4467542
Low 0.216 0.15
No. of Samples 72 308

Five-year Rolling Average

  • Annual Mean
Pass

Dissolved Oxygen Saturation

Note: Low DO saturation also may be naturally influenced by inflows from nearby wetlands or groundwater sources.
Score: Pass
Units: percent (%) Year
2012		 Historical
period of record
High 118.50 144.70
Mean 47.83 53.31 34.07776
Low 8.10 4.20
No. of Samples 63 347

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2012		 Historical
period of record
High 8.44 9.01
Mean 1.14 1.04 1.41441
Low 0.50 0.50
No. of Samples 68 285

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2012		 Historical
period of record
High 65.00
Mean 43.6 14.68181
Low 20.00
No. of Samples 0 10

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2012		 Historical
period of record
High 0.609 0.609
Mean 0.08 0.09 0.12519234
Low 0.014 0.0004
No. of Samples 72 306

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2012		 Historical
period of record
High 1.86 1.86
Mean 0.73 0.7 0.3015924
Low 0.47 0.00
No. of Samples 72 307

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2012		 Historical
period of record
High 0.597 0.681
Mean 0.08 0.09 0.15918298
Low 0.004 0.004
No. of Samples 72 307

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2012		 Historical
period of record
High 7.77 9.10
Mean 7.36 7.57 0.33337
Low 6.91 6.64
No. of Samples 66 260

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2012		 Historical
period of record
High 12.17 12.17
Mean 0.41 0.38 1.41346
Low 0.11 0.04
No. of Samples 66 233

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2012		 Historical
period of record
High 20313.00 54000.00
Mean 842.29 888.41 12519.43171
Low 235.00 0.445
No. of Samples 66 257

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2012		 Historical
period of record
High 82.31 91.40
Mean 73.42 72.63 7.56921
Low 67.10 53.87
No. of Samples 44 209

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2012		 Historical
period of record
High 26.00 38.00
Mean 4.44 3.49 3.68209
Low 1.30 1.00
No. of Samples 72 307

Five-year Rolling Average

  • Annual Mean
Other Measures of Creek Health:

Water Chemistry Ratings | Tidal Portion of the Creek

Creek Conditions Ratings are based on comparing nitrogen, phosphorus, chlorophyll and dissolved oxygen to water quality guidelines or regulations. Florida law defines a maximum allowable concentration of chlorophyll a and a minimum allowable concentration of dissolved oxygen in these streams. Florida has no regulatory thresholds for nitrogen or phosphorus in tidal creeks so trends are used to rate the creeks. Learn more about these ratings and how they are calculated »

Data for the following WBIDs is averaged when compiling the data below:
  • 1951
  • 1953
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Pass

Chlorophyll a

Score: Pass
Units: mg/L Year
2012		 Historical
period of record
High 0.0 0.1
Mean 0.0009 0.0029 0.0094896
Low 0.0003 0.0003
No. of Samples 12 157

Five-year Rolling Average

  • Annual Mean
×

Chlorophyll a

The rating for Chlorophyll a is determined by comparing the annual arithmetic mean of its sampled values to fixed target and threshold values. The annual arithmetic mean is shown in the graph at left, as compared to its established target and threshold values.

An arithmetic mean is used for Chlorophyll a for consistency with the Surface Water Quality Standards, Florida Administrative Code 62-302.532, Estuary-Specific Numeric Interpretations of the Narrative Nutrient Criterion.

Pass

Nitrogen, Total

No trend was observed after performing a trend analysis.
Score: Pass
Units: mg/L Year
2012		 Historical
period of record
High 0.8 1.9
Mean 0.706 0.8558 0.30103994
Low 0.621 0.34
No. of Samples 4 129

Five-year Rolling Average

  • Annual Mean
×

Nitrogen, Total

Caution

Phosphorus, Total

Trend analysis shows a weak increasing trend.
Score: Caution
Units: mg/L Year
2012		 Historical
period of record
High 0.7 1.3
Mean 0.5815 0.3484 0.2427637
Low 0.502 0.05
No. of Samples 12 197

Five-year Rolling Average

  • Annual Mean
×

Phosphorus, Total

Caution

Dissolved Oxygen Saturation

Note: Low DO saturation also may be naturally influenced by inflows from nearby wetlands or groundwater sources
Score: Caution
Units: percent (%) Year
2012		 Historical
period of record
High 84.3 128.7
Mean 27.67 38.49 26.35312
Low 9.70 0.70
No. of Samples 12 293

Five-year Rolling Average

  • Annual Mean
×

Dissolved Oxygen Saturation

BOD, Biochemical oxygen demand

Units: mg/l Year
2012		 Historical
period of record
High 2.1 5.4
Mean 1.05 1.63 1.06247
Low 0.50 0.50
No. of Samples 10 137

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2012		 Historical
period of record
High 125.0
Mean 23.7 22.74227
Low 5.00
No. of Samples 0 121

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2012		 Historical
period of record
High 0.1 0.9
Mean 0.04 0.02 0.12857152
Low 0.021 0.00
No. of Samples 12 244

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2012		 Historical
period of record
High 0.5 1.9
Mean 0.46 0.71 0.30161812
Low 0.426 0.16
No. of Samples 12 243

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2012		 Historical
period of record
High 0.3 0.7
Mean 0.24 0.09 0.15876776
Low 0.172 0.00
No. of Samples 12 205

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2012		 Historical
period of record
High 7.5 8.4
Mean 6.87 7.6 0.47847
Low 6.38 6.38
No. of Samples 12 245

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2012		 Historical
period of record
High 24.9 34.7
Mean 7.98 17.52 10.05493
Low 0.52 0.35
No. of Samples 12 216

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2012		 Historical
period of record
High 39,018.0 53,000.0
Mean 13550.04 30173.85 13910.31347
Low 1051.00 46.582
No. of Samples 12 326

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2012		 Historical
period of record
High 75.3 94.2
Mean 72.68 75.29 8.25388
Low 71.006 51.80
No. of Samples 8 233

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2012		 Historical
period of record
High 7.0 42.0
Mean 3.61 4.71 4.37313
Low 2.30 0.27
No. of Samples 12 260

Five-year Rolling Average

  • Annual Mean
Other Measures of Creek Health:

Oysters

Because they are immobile and will tolerate a fairly wide salinity range, eastern oysters (Crassostrea virginica) are valuable as an indicator of the relative health of aquatic ecosystems in the tidally-influenced portions of coastal creeks. Sarasota County has established an oyster monitoring program to track the location, types, and status of oyster reefs. Data from this monitoring program is shown below. Learn more about Oysters »

Loading oyster site map...
Most Recent Sarasota County Oyster Monitoring Program Data
Icon Site ID Year Dead Live Total % Live
1 HUD2 2011 74 176 250 70

Impervious Features

Hudson Bayou is located within the Sarasota Bay Watershed. View details about the Sarasota Bay Watershed »

Rain that falls on land that is in a natural state is absorbed and filtered by soils and vegetation as it makes it way into underground aquifers. However, in developed areas, "impervious surfaces" impede this process and contribute to polluted urban runoff entering surface waters. These surfaces include human infrastructure like roads, sidewalks, driveways and parking lots that are covered by impenetrable materials such as asphalt, concrete, brick and stone, as well as buildings and other permanent structures. Soils that have been disturbed and compacted by urban development are often impervious as well. Learn more about Impervious Features »

The Sarasota County Stormwater Environmental Utility (SEU) mapped impervious surfaces in the County in 2013. A map showing impervious surfaces can be viewed using the Water Atlas Map Viewer tool.

47% of the land area within the Hudson Bayou Basin is covered by impervious surfaces

Impervious Surface Coverage by Type

Land Use / Land Cover

Hudson Bayou is located within the Sarasota Bay Watershed. View details about the Sarasota Bay Watershed »

Land use within a creek's watershed has a major effect on its water quality. In general, less development means better water quality. Land Cover/Land Use classifications categorize land in terms of its observed physical surface characteristics (e.g. upland or wetland), and also reflect the types of activity that are taking place on it (agriculture, urban/built-up, utilities, etc.). Florida uses as its standard a set of statewide classifications which were developed by the Florida Department of Transportation. Learn more about Land Use and Land Cover »

Acreage and Percentage within each Land Use / Land Cover Category for Hudson Bayou Basin
Land Use Classification 1990 1995 1999 2005 2011 2014 2017 2020 Trend
Urban & Built-up 2,22492.4% 2,24493.3% 2,24393.2% 2,26093.9% 2,26093.9% 2,24993.5% 2,26093.9% 2,25993.9% Land Use Trend Sparkline
Upland Forests 160.7% 90.4% 90.4% 00% 00% 00% 00% 00% Land Use Trend Sparkline
Water 241% 251% 261.1% 261.1% 271.1% 271.1% 271.1% 271.1% Land Use Trend Sparkline
Wetlands 160.7% 130.5% 130.5% 100.4% 100.4% 100.4% 100.4% 100.4% Land Use Trend Sparkline
Transportation and Utilities 1265.2% 1154.8% 1154.8% 1094.6% 1094.6% 1205% 1094.5% 1104.6% Land Use Trend Sparkline
Land Use Chart