Current Conditions Yearly Table View

The table below shows the most recently collected long term fixed station data, as well as comparisons of current conditions with historical averages.

Notice: The data provided in the table below is also available in a text-based accessible data table.

For full-screen table view click here.

Select a Year, Sampling Location, and Parameter:

2026 Chesapeake Bay Mainstem - Bottom Dissolved Oxygen (mg/L)

23 stations available.

Click on hyperlinked stations to view charts of water quality trends.

Stations Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
CB1.0 - Susquehanna River (Conowingo) 13.5 13.8 10.6 10.9 8.7
CB1.1 - Mouth of Susquehanna River 13.9 12.1 10.1 9.6 7.5
CB2.1 - Turkey Point 13.4 11.8 10 9.4 7.4
CB2.2 - Still Pond 12.3 10.8 9.4 7.5 3.6
CB3.1 - Gunpowder Neck 10.3 9.3 6.8 5.1 0.65
CB3.2 - Swan Point 9.1 9.5 6 3.8 0.75
CB3.3W - Bay Bridge (NW) 10.3 9.3 6 1.55
CB3.3E - Bay Bridge (NE) 11 10.6 5.5 3.85
CB3.3C - Bay Bridge (N) 9 9.3 6.8 2.4 1.55
CB4.1C - Kent Point (SW) 9.2 11.9 9.3 6.9 3 2
CB4.1E - Kent Point (S) 9.7 6.9 2.7 1.5
CB4.1W - Horseshoe Point 10.3 10.2 6 5.6
CB4.2E - Tilghman Island 11.6 9.4 8.6 4.7
CB4.2C - MD Mid Bay 9.2 11.9 9.9 6.6 3.8 2.25
CB4.2W - Plum Point 11.1 9.4 8.9 4.6
CB4.3W - Dares Beach 11.3 9.2 8.4 5.15
CB4.3E - Mouth of Choptank River 9.8 7.8 3.4 2.25
CB4.3C - Dares Beach 9.4 11.9 9.9 7 3.9 2.35
CB4.4 - Cove Point 9.5 12 9.7 7.3 4.2 2.65
CB5.1W - Mouth of Patuxent River 11.6 13.5 13.8 9.7 6.2 3.8
CB5.1 - Cedar Point 9.9 11.9 9.5 6.7 4.9 2.8
CB5.2 - Point No Point 10.3 11.8 10.1 7.3 5.9 3.25
CB5.3 - Smith Point 10.3 11.8 8.6 6.3 3.8

Bottom Dissolved Oxygen (mg/l)
  • Purple 0.0 - 0.2 (anoxia - kills most life)
  • Red 0.2 - 2.0 (hypoxia - harms bottom organisms)
  • Orange 2.0 - 3.0 (stresses smaller fish and crabs)
  • Yellow 3.0 - 5.0 (stresses larger fish)
  • Green 5.0 - 10.0 (healthy)
  • Blue 10.0 + (could indicate an algal bloom in summer)
  • Gray No Data

Dissolved oxygen (DO) in the water sustains life for Bay organisms. Nutrients, such as nitrogen and phosphorus, from agricultural, sewer/septic and urban sources can fuel algal blooms that can starve the water of DO. DO levels above 5 mg/l are normally sufficient to support most life.

More info on: "Our Monitoring Explained" (opens in a new tab)