Whitaker Bayou Condition Report for 2017

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

3 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: 4,967 acres
  • Location: North Sarasota County, south Manatee 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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Whitaker Bayou

Whitaker Bayou
Visit the Whitaker 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:
  • 1936A
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Pass

Chlorophyll a

Score: Pass
Units: ug/l Year
2017		 Historical
period of record
High 11.40 59.50
Mean 0.5799 1.8011 5.3586
Low 0.25 0.00
No. of Samples 12 589

Five-year Rolling Average

  • Annual Mean
Pass

Nitrogen, Total

Score: Pass
Units: mg/L Year
2017		 Historical
period of record
High 1.501 15.76
Mean 1.0484 0.9148 1.53135895
Low 0.714 0.30
No. of Samples 12 350

Five-year Rolling Average

  • Annual Mean
Pass

Phosphorus, Total

Score: Pass
Units: mg/L Year
2017		 Historical
period of record
High 0.434 2.38
Mean 0.2352 0.3029 0.22706616
Low 0.094 0.082
No. of Samples 13 604

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
2017		 Historical
period of record
High 105.90 262.30
Mean 69.5 84.54 42.14878
Low 48.20 7.0588
No. of Samples 12 713

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2017		 Historical
period of record
High 1.58 175.00
Mean 1.05 0.88 17.2118
Low 1.00 0.50
No. of Samples 12 537

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2017		 Historical
period of record
High 90.00 220.00
Mean 59.07 73.14 33.65834
Low 35.00 20.00
No. of Samples 12 147

Five-year Rolling Average

  • Annual Mean

Escherichia coli

Units: MPN/100ml Year
2017		 Historical
period of record
High 9804.00 14136.00
Mean 3846.39 3948.02 3489.12836
Low 583.00 97.00
No. of Samples 12 39

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2017		 Historical
period of record
High 0.101 30.06
Mean 0.05 0.02 2.17811063
Low 0.023 0.00
No. of Samples 2 652

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2017		 Historical
period of record
High 1.21 15.36
Mean 0.76 0.78 1.10863297
Low 0.499 0.20
No. of Samples 13 647

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2017		 Historical
period of record
High 0.59 1.02
Mean 0.24 0.08 0.15963896
Low 0.112 0.00
No. of Samples 12 616

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2017		 Historical
period of record
High 8.00 11.77
Mean 7.68 7.67 0.36876
Low 7.20 6.10
No. of Samples 24 875

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2017		 Historical
period of record
High 0.80 23.40
Mean 0.42 0.39 1.53243
Low 0.20 0.00
No. of Samples 11 702

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2017		 Historical
period of record
High 1593.00 49645.00
Mean 967.37 663.53 4763.77227
Low 583.00 0.524
No. of Samples 12 904

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2017		 Historical
period of record
High 84.38 91.40
Mean 75.71 69.26 9.36706
Low 62.492 14.018
No. of Samples 12 789

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2017		 Historical
period of record
High 6.70 56.40
Mean 1.52 2.9 5.2183
Low 0.66 0.50
No. of Samples 11 668

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:
  • 1936
Chart Legend
  • Trend Line
  • Annual Mean
  • Threshold
Pass

Chlorophyll a

Score: Pass
Units: ug/l Year
2017		 Historical
period of record
High 40.2 128.0
Mean 9.0977 11.9426 24.09013
Low 2.71 0.38
No. of Samples 12 207

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.

Nitrogen, Total

We were unable to determine a trend for the data available.
Units: mg/L Year
2017		 Historical
period of record
High 1.3 7.0
Mean 0.9344 1.1361 1.42472883
Low 0.597 0.054
No. of Samples 8 144

Five-year Rolling Average

  • Annual Mean
×

Nitrogen, Total

Phosphorus, Total

We were unable to determine a trend for the data available.
Units: mg/L Year
2017		 Historical
period of record
High 0.3 2.0
Mean 0.1966 0.2352 0.38530246
Low 0.109 0.038
No. of Samples 11 250

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
2017		 Historical
period of record
High 78.3 381.3
Mean 48.82 63.08 30.03658
Low 10.80 0.00
No. of Samples 9 591

Five-year Rolling Average

  • Annual Mean
×

Dissolved Oxygen Saturation

BOD, Biochemical oxygen demand

Units: mg/l Year
2017		 Historical
period of record
High 4.8 12.7
Mean 2.21 2.4 2.1837
Low 1.00 0.543
No. of Samples 12 194

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2017		 Historical
period of record
High 80.0 200.0
Mean 36.46 51.87 28.81003
Low 10.00 10.00
No. of Samples 12 157

Five-year Rolling Average

  • Annual Mean

Enterococcus Group Bacteria

Units: MPN/100ml Year
2017		 Historical
period of record
High 17,000.0 17,000.0
Mean 366.78 270.91 2892.94236
Low 10.00 10.00
No. of Samples 12 39

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2017		 Historical
period of record
High 0.0 1.9
Mean 0.02 0.01 0.18495107
Low 0.024 0.00
No. of Samples 1 290

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2017		 Historical
period of record
High 1.2 6.3
Mean 0.86 0.87 0.90840577
Low 0.542 0.05
No. of Samples 12 297

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2017		 Historical
period of record
High 0.2 3.3
Mean 0.06 0.07 0.35442422
Low 0.01 0.004
No. of Samples 8 245

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2017		 Historical
period of record
High 8.2 8.8
Mean 7.79 7.61 0.40557
Low 7.10 4.90
No. of Samples 24 2,876

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2017		 Historical
period of record
High 36.9 45.0
Mean 31.82 6.05 15.34934
Low 14.90 0.00
No. of Samples 13 2,903

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2017		 Historical
period of record
High 54,936.0 55,760.0
Mean 47461.79 7283.26 22680.83246
Low 24566.00 320.00
No. of Samples 11 2,707

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2017		 Historical
period of record
High 89.1 95.5
Mean 79.16 74.56 6.11517
Low 69.116 49.10
No. of Samples 13 3,046

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2017		 Historical
period of record
High 6.2 31.3
Mean 4.36 3.85 3.28585
Low 2.90 0.62
No. of Samples 10 561

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...

Impervious Features

Whitaker 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.

27% of the land area within the Whitaker Bayou Basin is covered by impervious surfaces

Impervious Surface Coverage by Type

Land Use / Land Cover

Whitaker 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 Whitaker Bayou Basin
Land Use Classification 1990 1995 1999 2005 2011 2014 2017 2020 Trend
Urban & Built-up 3,83077.1% 3,83477.2% 3,83177.1% 3,90378.6% 3,95279.6% 3,92179% 3,95179.6% 3,97079.9% Land Use Trend Sparkline
Agriculture 2144.3% 1823.7% 1883.8% 1813.6% 1813.6% 1813.6% 1783.6% 1683.4% Land Use Trend Sparkline
Rangeland 40.1% 40.1% 40.1% 40.1% 40.1% 40.1% 40.1% 40.1% Land Use Trend Sparkline
Upland Forests 2354.7% 2495% 2495% 1953.9% 1643.3% 1953.9% 1643.3% 1583.2% Land Use Trend Sparkline
Water 1302.6% 1372.7% 1402.8% 1262.5% 881.8% 881.8% 891.8% 911.8% Land Use Trend Sparkline
Wetlands 3156.4% 2324.7% 2274.6% 2294.6% 2224.5% 2224.5% 2224.5% 2214.4% Land Use Trend Sparkline
Barren Land 00% 00% 00% 00% 00% 00% 30.1% 00% Land Use Trend Sparkline
Transportation and Utilities 2384.8% 3296.6% 3296.6% 3286.6% 3567.2% 3567.2% 3557.2% 3567.2% Land Use Trend Sparkline
Land Use Chart