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

4 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

The Hudson Bayou Basin is entirely within the bounds of the City of Sarasota. Its surface water system has undergone significant alteration over the past century. The Sarasota County 1847 General Land Office Survey does not confirm Hudson Bayou but does show a few inland waterways. The 1959 USDA NRCS Soil Survey Map shows that Hudson Bayou extended about 1 mile inland from the bay through somewhat poorly drained soil associated with flatwoods. The survey also shows an area of well-drained soil likely consisting of scrub land north of the bayou, which continues north along the coast. For basin details see: Sarasota Bay Water Quality Management Plan (2012)

Hudson Bayou

Hudson Bayou

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
2013
Historical
period of record
High 0.0119 0.1568
Mean 0.0009 0.0013 0.01433695
Low 0.0002 0.0002
No. of Samples 70 371

Five-year Rolling Average

  • Annual Mean
Pass

Nitrogen, Total

Score: Pass
Units: mg/l Year
2013
Historical
period of record
High 1.544 1.866
Mean 0.822 0.8211 0.31054588
Low 0.054 0.054
No. of Samples 22 183

Five-year Rolling Average

  • Annual Mean
Pass

Phosphorus, Total

Score: Pass
Units: mg/l Year
2013
Historical
period of record
High 1.48 4.05
Mean 0.4738 0.4763 0.43015757
Low 0.236 0.15
No. of Samples 70 378

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 101.20 144.70
Mean 47.32 52.12 32.65137
Low 11.30 4.20
No. of Samples 81 428

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2013
Historical
period of record
High 7.55 9.01
Mean 0.72 0.97 1.47768
Low 0.50 0.50
No. of Samples 70 355

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2013
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: ug/l Year
2013
Historical
period of record
High 328.00 609.00
Mean 42.33 79.74 121.00316
Low 8.00 0.4065
No. of Samples 70 376

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: ug/l Year
2013
Historical
period of record
High 1540.00 1860.00
Mean 606.74 680.68 306.20682
Low 50.00 0.00
No. of Samples 70 377

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: ug/l Year
2013
Historical
period of record
High 506.00 681.00
Mean 130.94 99.3 158.70725
Low 4.00 4.00
No. of Samples 70 377

Five-year Rolling Average

  • Annual Mean

pH

Units: None Year
2013
Historical
period of record
High 7.70 9.10
Mean 7.28 7.5 0.3403
Low 6.62 6.62
No. of Samples 81 341

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2013
Historical
period of record
High 3.29 12.17
Mean 0.4 0.38 1.28056
Low 0.16 0.04
No. of Samples 66 299

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2013
Historical
period of record
High 6052.00 54000.00
Mean 756.19 854.76 11052.16928
Low 337.00 0.445
No. of Samples 81 338

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2013
Historical
period of record
High 83.318 91.40
Mean 72.55 72.61 7.53576
Low 59.00 53.87
No. of Samples 59 268

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2013
Historical
period of record
High 9.70 38.00
Mean 3.59 3.51 3.42652
Low 2.10 1.00
No. of Samples 70 377

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

Chlorophyll a

Units: mg/l Year
2013
Historical
period of record
High 0.1
Mean 0.0029 0.0094896
Low 0.0003
No. of Samples 0 157

Five-year Rolling Average

  • Annual Mean

Nitrogen, Total

We were unable to determine a trend for the data available.
Units: mg/l Year
2013
Historical
period of record
High 1.9
Mean 0.8558 0.30103994
Low 0.34
No. of Samples 0 129

Five-year Rolling Average

  • Annual Mean

Phosphorus, Total

We were unable to determine a trend for the data available.
Units: mg/l Year
2013
Historical
period of record
High 1.3
Mean 0.3484 0.2427637
Low 0.05
No. of Samples 0 197

Five-year Rolling Average

  • Annual Mean

Dissolved Oxygen Saturation

Note: Low DO saturation also may be naturally influenced by inflows from nearby wetlands or groundwater sources
Units: percent (%) Year
2013
Historical
period of record
High 128.7
Mean 38.49 26.35312
Low 0.70
No. of Samples 0 293

Five-year Rolling Average

  • Annual Mean

BOD, Biochemical oxygen demand

Units: mg/l Year
2013
Historical
period of record
High 5.4
Mean 1.63 1.06247
Low 0.50
No. of Samples 0 137

Five-year Rolling Average

  • Annual Mean

Color

Units: PCU Year
2013
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: ug/l Year
2013
Historical
period of record
High 912.0
Mean 23.48 128.57152
Low 0.00
No. of Samples 0 244

Five-year Rolling Average

  • Annual Mean

Nitrogen, Kjeldahl

Units: ug/l Year
2013
Historical
period of record
High 1,946.0
Mean 707.74 301.61812
Low 160.00
No. of Samples 0 243

Five-year Rolling Average

  • Annual Mean

Nitrogen, Nitrite + Nitrate as N

Units: ug/l Year
2013
Historical
period of record
High 656.0
Mean 90.66 158.76776
Low 0.00
No. of Samples 0 205

Five-year Rolling Average

  • Annual Mean

Oysters

Units: Year
2013
Historical
period of record
High 543.0
Mean 65.57
Low 161.00
No. of Samples 469 3,694

Five-year Rolling Average

pH

Units: None Year
2013
Historical
period of record
High 8.4
Mean 7.6 0.47847
Low 6.38
No. of Samples 0 245

Five-year Rolling Average

  • Annual Mean

Salinity

Units: PSS Year
2013
Historical
period of record
High 34.7
Mean 17.52 10.05493
Low 0.35
No. of Samples 0 216

Five-year Rolling Average

  • Annual Mean

Specific conductance

Units: umho Year
2013
Historical
period of record
High 53,000.0
Mean 30173.85 13910.31347
Low 46.582
No. of Samples 0 326

Five-year Rolling Average

  • Annual Mean

Temperature, water

Units: deg F Year
2013
Historical
period of record
High 94.2
Mean 75.29 8.25388
Low 51.80
No. of Samples 0 233

Five-year Rolling Average

  • Annual Mean

Turbidity

Units: NTU Year
2013
Historical
period of record
High 42.0
Mean 4.71 4.37313
Low 0.27
No. of Samples 0 260

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 2013 152 317 469 68

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 2011 2014 Trend
Urban & Built-up 2,22492.4% 2,26093.9% 2,24993.5% Land Use Trend Sparkline
Upland Forests 160.7% 00% 00% Land Use Trend Sparkline
Water 241% 271.1% 271.1% Land Use Trend Sparkline
Wetlands 160.7% 100.4% 100.4% Land Use Trend Sparkline
Transportation and Utilities 1265.2% 1094.6% 1205% Land Use Trend Sparkline
Land Use Chart