Text Size: A  A  A

Dissolved Oxygen (Volume Assessment)

Tracking of this indicator has been discontinued due to the Chesapeake Bay Program’s focus on tracking dissolved oxygen through surface area assessments that are part of its Water Quality Standards Attainment indicator. For more information, visit ChesapeakeProgress.


Like animals on land, living creatures in the Chesapeake Bay need oxygen to survive. In the water, oxygen is present in dissolved form. Without adequate concentrations of dissolved oxygen, the Bay’s ability to support aquatic life is compromised.

Dissolved oxygen concentrations are an important indicator of nutrient pollution. This is because low dissolved oxygen levels are often the result of nutrient-fueled algae blooms. When algae blooms die and undergo bacterial decomposition, these bacteria use up oxygen in the water, leaving little for fish and shellfish and creating what are known as “dead zones.” Increased nutrient pollution leads to larger algae blooms, which in turn create more dead zones.

Over time, large-scale reductions in the amount of nutrients flowing into the Bay will help improve low-oxygen conditions.


In 2014, the Chesapeake Bay Program adopted a goal to reduce pollution and achieve the water quality necessary to protect human health and support the region’s underwater resources. Our partners are working to bring 100 percent of the Bay and its tidal tributaries up to dissolved oxygen standards.

Source of Data

Chesapeake Bay Program

410 Severn Avenue / Suite 112
Annapolis, Maryland 21403
Tel: (800) YOUR-BAY / Fax: (410) 267-5777
Directions to the Bay Program Office
Terms of Use | Privacy Policy
©2012 Chesapeake Bay Program | All Rights Reserved