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

4 out of 4 primary indicators were rated as PASS.

"Primary" are nutrient related (Chl, N, P) and bacteria (B) parameters.

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

Greyed out values indicate no data for the report year.

  • Size: 3,984 acres
  • Location: North and central Sarasota County
  • Discharges into: Little Sarasota Bay

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

View county-wide water quality trends »

Catfish Creek

Water Chemistry Ratings

Monitoring data is analyzed to determine stream health based on State water quality standards. Official determination of impairment or attainment of the water quality standards is performed by FDEP and is based on at least three years and up to seven and a half years of data. Information on approximately 17 different parameters are collected at stream sites, but only total nitrogen, total phosphorus, chlorophyll a, dissolved oxygen (percent saturation), and bacteria are assessed according to established water quality criteria mandated by the Clean Water Act. Additionally, the floral and faunal communities (SCI) are assessed at some sites to determine whether waters support a healthy aquatic community.

The "pass/fail" conditions presented here do not indicate impairment as determined by the official Florida Department of Environmental Protection Impaired Waters Rule assessment but, rather, give an indication of stream condition in a particular year in relation to the set regulatory numeric limits. Streams receive an annual "PASS" rating for each parameter if the mean value is below the regulatory value and a "FAIL" rating if the mean value exceeds the regulatory value. Not all water quality parameters have an established numeric criterion, so only some of the graphs below show the regulatory limit, represented by a horizontal red line.

Chart Legend
  • Monthly Average
  • Threshold
  • Annual Mean

The graphs here illustrate results over the past five years. Data from sites monitored within a single waterbody identification basin (WBID) are combined to determine water quality status for each WBID, and the annual geometric mean of sample results is indicated on the graph for the most recent year. The table to the left of the graph gives the annual and historic range of values for the indicator.

Click the graph to view a larger image and to download the full dataset.

Freshwater Portion of the Creek

Data for the following WBIDs is averaged when compiling the data below:
  • 1984AA
  • 1984B

Chlorophyll a

Units: µg/l Year
2025
Historical
period of record
High 71.50 396.00
Mean 12.0445 9.0051 22.45796
Low 1.64 0.10
No. of Samples 24 812
  • Monthly Average
  • NNC 20.00 µg/l
  • Annual Mean

Nitrogen, Total

Units: mg/L Year
2025
Historical
period of record
High 2.007 5.13
Mean 1.083 1.0769 0.45462039
Low 0.623 0.0017
No. of Samples 24 632
  • Monthly Average
  • NNC 1.65 mg/L
  • Annual Mean

Phosphorus, Total

Units: mg/L Year
2025
Historical
period of record
High 0.158 4.61
Mean 0.096 0.1402 0.27525647
Low 0.038 0.008
No. of Samples 24 815
  • Monthly Average
  • NNC 0.49 mg/L
  • Annual Mean

Dissolved Oxygen Saturation

Note: Dissolved oxygen saturation percentages above the regulatory threshold meet established water quality targets.
Units: percent (%) Year
2025
Historical
period of record
High 130.83 920.00
Mean 81.41 62.76 42.58346
Low 44.69 0.00
No. of Samples 24 837
  • Monthly Average
  • NNC 38.00 percent (%)
  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2025
Historical
period of record
High 5.50 17.50
Mean 2.3 1.41 1.33265
Low 1.00 0.50
No. of Samples 24 756
  • Monthly Average
  • Annual Mean

Color

Units: PCU Year
2025
Historical
period of record
High 100.00 400.00
Mean 59.94 65.2 32.08676
Low 30.00 15.00
No. of Samples 24 846
  • Monthly Average
  • Annual Mean

Escherichia coli

Units: MPN/100ml Year
2025
Historical
period of record
High 336.00 7270.00
Mean 44.28 60.33 450.89452
Low 10.00 10.00
No. of Samples 24 313
  • Monthly Average
  • Annual Mean

Nitrogen, Ammonia + Ammonium as N

Units: mg/L Year
2025
Historical
period of record
High 0.13 3.68
Mean 0.04 0.02 0.19160491
Low 0.008 0.00
No. of Samples 24 887
  • Monthly Average
  • Annual Mean

Nitrogen, Kjeldahl

Units: mg/L Year
2025
Historical
period of record
High 1.91 4.49
Mean 1.02 1.02 0.42712475
Low 0.611 0.00
No. of Samples 24 874
  • Monthly Average
  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: mg/L Year
2025
Historical
period of record
High 0.214 0.895
Mean 0.04 0.04 0.1084742
Low 0.011 0.00
No. of Samples 24 810
  • Monthly Average
  • Annual Mean

pH

Units: None Year
2025
Historical
period of record
High 8.26 9.13
Mean 7.7 7.62 0.34275
Low 7.13 3.37
No. of Samples 24 944
  • Monthly Average
  • Annual Mean

Salinity

Units: PSS Year
2025
Historical
period of record
High 4.08 56.00
Mean 0.68 0.59 3.73859
Low 0.34 0.00
No. of Samples 24 813
  • Monthly Average
  • Annual Mean

Specific conductance

Units: µmho Year
2025
Historical
period of record
High 7310.07 52500.00
Mean 1335.79 1393.25 9128.08027
Low 698.49 0.379
No. of Samples 24 915
  • Monthly Average
  • Annual Mean

Temperature, water

Units: °F Year
2025
Historical
period of record
High 192.5348 192.5348
Mean 172.41 88.69 39.2642
Low 144.2588 49.28
No. of Samples 24 733
  • Monthly Average
  • Annual Mean

Turbidity

Units: NTU Year
2025
Historical
period of record
High 54.00
Mean 3.3 4.26221
Low 0.30
No. of Samples 0 683
  • Monthly Average
  • Annual Mean
Other Measures of Creek Health:

Tidal Portion of the Creek

Data for the following WBIDs is averaged when compiling the data below:
  • 1984
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 CAT1 2013 0 0 0 0
2 NC1 2025 71 328 399 82
3 NC2 2013 0 0 0 0
4 NC2A 2013 21 54 75 72

Impervious Features

Catfish Creek is located within the Little Sarasota Bay Watershed. View details about the Little 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.

24% of the land area within the Catfish Creek Basin is covered by impervious surfaces

Impervious Surface Coverage by Type

Land Use / Land Cover

Catfish Creek is located within the Little Sarasota Bay Watershed. View details about the Little 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 Catfish Creek Basin
Land Use Classification 1990 1995 1999 2005 2011 2014 2017 2020 2023 Trend
Urban & Built-up 1,71443% 2,04151.2% 2,47962.2% 2,66766.9% 2,69867.7% 2,60365.3% 2,74668.9% 2,77569.6% 2,76769.4% Land Use Trend Sparkline
Agriculture 64316.1% 55714% 2867.2% 1513.8% 1293.2% 1132.8% 1042.6% 761.9% 731.8% Land Use Trend Sparkline
Rangeland 360.9% 220.5% 360.9% 120.3% 30.1% 30.1% 30.1% 30.1% 30.1% Land Use Trend Sparkline
Upland Forests 86021.6% 65016.3% 3157.9% 2185.5% 1954.9% 2345.9% 1724.3% 1634.1% 1634.1% Land Use Trend Sparkline
Water 1854.6% 2736.8% 3759.4% 3759.4% 3859.7% 3849.6% 3899.8% 3789.5% 3799.5% Land Use Trend Sparkline
Wetlands 44211.1% 3719.3% 3909.8% 3899.8% 40910.3% 43811% 40410.2% 42410.6% 43410.9% Land Use Trend Sparkline
Barren Land 370.9% 00% 40.1% 70.2% 00% 00% 00% 00% 00% Land Use Trend Sparkline
Transportation and Utilities 661.7% 701.8% 982.5% 1654.1% 1654.1% 2095.2% 1654.1% 1654.1% 1654.1% Land Use Trend Sparkline
Land Use Chart