United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/620/R-00/005J
October, 1999
Coastal Communications
Dissolved Oxygen: Moving Towards
National Marine Water Quality Criteria
Background
Researchers at the U.S.EPA's Office of Research and Development have conducted studies designed to aid in
ithe development of saltwater dissolved oxygen criteria (DO) for over 15
wears. This effort, largely conducted by the Atlantic Ecology Division
j(AED), was focused on the effects of low dissolved oxygen on coastal and
lestuarine organisms found in the Virginian Province, a region located
(between Cape Cod, MA and Cape Hatteras, NIC. The approach combined
^features of traditional Water Quality Criteria (WQC) with a new biological
jframework that includes a temporal, or time, component for fluxes in DO,
Jand establishes separate criteria for different life stages (larvae versus
AEb's flow-through DO testing juveniles and adults).
system
Draft DO WQC Criteria
The U.S. EPA's Office of Water, using information from these
studies, published draft WQC for dissolved oxygen for marine
waters in the Virginian Province. The criteria apply to both
continuous (persistent) and cyclic (diel, tidal, or episodic)
hypoxia. The limits identified are based on laboratory findings,
but are supported in part by field observations.
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Exposure Time (days)
Summary of criteria for persistent exposure. Criterion depends
on life stage exposed and the duration of the exposure (see
draft document for Ambient Water Quality Criteria for
Dissolved Oxygen—November 1999 for details).
Current Activities
Although, the geographic scope of this past effort was limited to
the Virginian Province of the Atlantic coast of the United
States, the framework is expected to work for other regions. AED is
collaborating with the Gulf Ecology Division in examining the
extrapolation of this framework to species from the southeast and
the Sulf of Mexico coasts. This study is expected to be completed by early 2001 and will establish the
applicability of the existing data for use in setting dissolved oxygen limits beyond the Virginian Province.
Future Activities
The ultimate goal is to provide EPA's Office of Water with the necessary data to create dissolved oxygen
criteria for all coastal regions of the contiguous United States. Once the work for the southeast and Gulf of
Mexico is completed, west coast efforts will begin. In collaboration with EPA's Western Ecology Division,
selection of species of concern for the Pacific coast of the United States should be completed in 2000, and
preliminary testing is tentatively scheduled for 2001.
Further Information
For further information, please contact &\er\ Thursby at the National Health and Environmental Effects
Research Laboratory's (NHEERL) Atlantic Ecology Division (401)782-3178 or thursby.glen@epa.gov; or
Laura Cairo (NHEERL/AED) at (401)782-9603 or coiro.laura@epa.gov. The text of the draft dissolved
oxygen criteria document is available at http://www.epa.gov/ost/standards/dissolved/.
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