Whitaker Bayou Condition Report for 2013

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
2013		 Historical
period of record
High 11.00 59.50
Mean 1.6107 1.9113 5.61295
Low 0.308 0.00
No. of Samples 80 485

Five-year Rolling Average

  • Annual Mean
Pass

Nitrogen, Total

Score: Pass
Units: mg/L Year
2013		 Historical
period of record
High 2.30 15.76
Mean 0.9773 0.9016 1.65368728
Low 0.553 0.30
No. of Samples 30 298

Five-year Rolling Average

  • Annual Mean
Pass

Phosphorus, Total

Score: Pass
Units: mg/L Year
2013		 Historical
period of record
High 0.78 2.38
Mean 0.307 0.3128 0.23607986
Low 0.12 0.082
No. of Samples 54 501

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
2013		 Historical
period of record
High 151.50 262.30
Mean 76.91 84.32 42.92483
Low 17.90 7.0588
No. of Samples 57 618

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2013		 Historical
period of record
High 3.80 175.00
Mean 0.75 0.91 18.89259
Low 0.50 0.50
No. of Samples 54 444

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2013		 Historical
period of record
High 220.00
Mean 76.7 34.68308
Low 20.00
No. of Samples 0 124

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2013		 Historical
period of record
High 0.59 30.06
Mean 0.02 0.02 2.34827668
Low 0.006 0.0001
No. of Samples 59 560

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2013		 Historical
period of record
High 2.00 15.36
Mean 0.78 0.78 1.20288831
Low 0.516 0.20
No. of Samples 54 544

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2013		 Historical
period of record
High 0.535 1.02
Mean 0.1 0.07 0.16006501
Low 0.009 0.00
No. of Samples 58 516

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2013		 Historical
period of record
High 7.90 11.77
Mean 7.55 7.67 0.38173
Low 6.96 6.10
No. of Samples 57 763

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2013		 Historical
period of record
High 0.44 20.48
Mean 0.33 0.39 1.02944
Low 0.21 0.00
No. of Samples 35 611

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2013		 Historical
period of record
High 49645.00 49645.00
Mean 822.82 643.63 4495.87239
Low 418.00 0.524
No. of Samples 57 812

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2013		 Historical
period of record
High 84.344 91.40
Mean 73.56 68.83 9.30675
Low 58.784 14.018
No. of Samples 46 711

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2013		 Historical
period of record
High 18.00 56.40
Mean 2.25 3.22 5.52281
Low 0.60 0.50
No. of Samples 53 567

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
Caution

Chlorophyll a

Score: Caution
Units: ug/l Year
2013		 Historical
period of record
High 66.4 120.0
Mean 17.1394 12.672 23.12904
Low 4.54 0.50
No. of Samples 35 110

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

Trend analysis shows a weak decreasing trend.
Score: Pass
Units: mg/L Year
2013		 Historical
period of record
High 1.5 7.0
Mean 0.8516 1.2568 1.62579276
Low 0.371 0.054
No. of Samples 11 100

Five-year Rolling Average

  • Annual Mean
×

Nitrogen, Total

Pass

Phosphorus, Total

Trend analysis shows a weak decreasing trend.
Score: Pass
Units: mg/L Year
2013		 Historical
period of record
High 0.3 2.0
Mean 0.1668 0.2834 0.44626544
Low 0.038 0.038
No. of Samples 35 157

Five-year Rolling Average

  • Annual Mean
×

Phosphorus, Total

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
2013		 Historical
period of record
High 91.2 381.3
Mean 58.64 63.15 30.69882
Low 12.50 0.00
No. of Samples 33 507

Five-year Rolling Average

  • Annual Mean
×

Dissolved Oxygen Saturation

BOD, Biochemical oxygen demand

Units: mg/l Year
2013		 Historical
period of record
High 12.7 12.7
Mean 2.66 2.68 2.35206
Low 1.26 1.00
No. of Samples 35 97

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2013		 Historical
period of record
High 200.0
Mean 54.6 28.46829
Low 10.00
No. of Samples 0 134

Five-year Rolling Average

  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2013		 Historical
period of record
High 0.1 1.9
Mean 0.02 0.02 0.21868879
Low 0.008 0.00
No. of Samples 35 201

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2013		 Historical
period of record
High 1.1 6.3
Mean 0.76 0.94 1.06047096
Low 0.359 0.05
No. of Samples 35 200

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2013		 Historical
period of record
High 0.5 3.3
Mean 0.04 0.09 0.40520824
Low 0.004 0.004
No. of Samples 35 163

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2013		 Historical
period of record
High 8.2 8.8
Mean 7.87 7.6 0.40839
Low 7.56 4.90
No. of Samples 33 2,767

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2013		 Historical
period of record
High 35.3 45.0
Mean 26.67 5.74 15.37845
Low 12.73 0.00
No. of Samples 33 2,811

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2013		 Historical
period of record
High 53,595.0 55,760.0
Mean 41690.54 6863.74 22595.93587
Low 21409.00 320.00
No. of Samples 33 2,624

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2013		 Historical
period of record
High 86.8 95.5
Mean 78.85 74.51 5.99737
Low 62.924 49.10
No. of Samples 22 2,970

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2013		 Historical
period of record
High 9.9 31.3
Mean 5.35 3.69 3.39454
Low 2.90 0.62
No. of Samples 35 466

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