Current Conditions Yearly Table View (Accessible)

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

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
CB1.1 - Mouth of Susquehanna River 13.9 - 12.1 10.1
CB2.1 - Turkey Point 13.4 - 11.8 10
CB2.2 - Still Pond 12.3 - 10.8 9.4
CB3.1 - Gunpowder Neck 10.3 - 9.3 6.8
CB3.2 - Swan Point 9.1 - 9.5 6
CB3.3W - Bay Bridge (NW) 10.3 9.3
CB3.3E - Bay Bridge (NE) 11 10.6
CB3.3C - Bay Bridge (N) 9 - 9.3 6.8
CB4.1C - Kent Point (SW) 9.2 11.9 9.3 6.9
CB4.1E - Kent Point (S) 9.7 6.9
CB4.1W - Horseshoe Point 10.3 10.2
CB4.2E - Tilghman Island 11.6 9.4
CB4.2C - MD Mid Bay 9.2 11.9 9.9 6.6
CB4.2W - Plum Point 11.1 9.4
CB4.3W - Dares Beach 11.3 9.2
CB4.3E - Mouth of Choptank River 9.8 7.8
CB4.3C - Dares Beach 9.4 11.9 9.9 7
CB4.4 - Cove Point 9.5 12 9.7 7.3
CB5.1W - Mouth of Patuxent River 11.6 13.5 13.8 9.7
CB5.1 - Cedar Point 9.9 11.9 9.5 6.7
CB5.2 - Point No Point 10.3 11.8 10.1 7.3
CB5.3 - Smith Point 10.3 11.8 - 8.6

Dissolved Oxygen Legend No Color
Bottom Dissolved Oxygen (mg/l)
0.0 - 0.2: Anoxia - kills most life
0.2 - 2.0: Hypoxia - harms bottom organisms
2.0 - 3.0: Stresses smaller fish and crabs
3.0 - 5.0: Stresses larger fish
5.0 - 10.0: Healthy
10.0 +: Could indicate an algal bloom in summer
- : 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"