Sarasota Bay Conditions

How healthy are our coastal waterways? Collected water quality data give us various measures of ecological health, but taken together, what do they tell us about the overall quality of our coastal systems? How do these measures compare from year to year? From bay to bay? Where has progress been made? Where is more effort needed?

The Conditions Overview below gives a comparison of the eight major bay systems that comprise Sarasota's coastal watersheds with regard to three important indicators of water quality. The Bay Conditions Index incorporates all three indicators, or you can view each indicator separately. Ratings are given on a calendar year basis, and are determined by comparing the average value of the selected indicators to target (desired) and threshold (undesirable) levels. Assessment of whether a particular indicator has exceeded its regulatory limit is performed solely by the Florida Department of Environmental Protection, and depictions on the Atlas are for information purposes only. Learn more about how threshold values were derived »

To view a page with more detailed condition information for a particular bay system, click on its name below. There you will find high, low, historical and average values for the water quality parameters used in determining the ratings, as well as other important measures of bay health, water quality contour maps, seagrass coverage maps, and watershed land use/land cover characteristics.

Bay Ratings

For a bay to receive a Pass rating, sample values for these indicators must meet or exceed established standards; otherwise, it receives a Caution rating.

View detailed indicator condition reports with additional comparisons and summaries by clicking on the coastal segment name from the list below.

The Bay Conditions Index gives a quick assessment of the water quality in each creek during a particular year by examining four important indicators of nutrient pollution: chlorophyll a, nitrogen, and phosphorus. The rating system used here was developed by a team of local water resource management professionals, incorporating the "numeric nutrient standards" proposed to the U.S. Environmental Protection Agency and based on research sponsored by the Sarasota Bay Estuary Program.

Each bay receives either a PASS or CAUTION rating, depending on whether sampling values for chlorophyll a, nitrogen, and phosphorus were below maximum thresholds established for that bay. A bay receives a PASS rating only if values for all three indicators are below their respective thresholds; otherwise, the bay receives a rating of CAUTION. Learn more about how ratings are assigned »

Indicator Health Icons
Indicator PASS rating CAUTION rating
Chlorophyll a Pass Rating Indicator Icon for Chlorophyll a CAUTION Rating Indicator Icon for Chlorophyll a
Nitrogen, Total Pass Rating Indicator Icon for Total Nitrogen CAUTION Rating Indicator Icon for Total Nitrogen
Phosphorus, Total Pass Rating Indicator Icon for Total Phosphorous CAUTION Rating Indicator Icon for Total Phosphorous