You are here:
MONITORING SPATIAL AND TEMPORAL VARIATIONS OF DISSOLVED OXYGEN IN ESTUARINE BOTTOM WATERS OF NORTHEASTERN, US
Citation:
Walker, H, J A. Kiddon, C. Deacutis, D J. Cobb, D. R. Kester, C. A. Oviatt, J F. Paul, AND B S. Brown. MONITORING SPATIAL AND TEMPORAL VARIATIONS OF DISSOLVED OXYGEN IN ESTUARINE BOTTOM WATERS OF NORTHEASTERN, US. Presented at American Society of Limnology and Oceanography, Salt Lake City, UT, February 8-14, 2003.
Description:
The U.S.EPA National Coastal Assessment (NCA) program is designed to address several
broad questions:1) what are the conditions of estuarine resources, how are they changing,
and what causes those changes; 2)which monitoring designs, indicators,and protocols are
appropriate for assessing estuarine conditions, particularly for assisting State efforts to
comply with the Clean Water Act requirements [e.g., 305(b)]. Estuarine data have been
collected in the U.S.over a two year period (2000-2001) using a probability - based
survey design. Assessment of estuarine dissolved oxygen (DO) conditions have been made
using EPA Marine Water Quality Criterion for the Northeast: <= 4.8 mg/L (chronic), <=
2.3 mg/L (acute). In the summer of 2000 and in estuarine bottom waters of the Gulf of
Maine, DO concentrations were always > 4.8 mg/L. Lower concentrations were observed
in stratified waters south of Cape Cod (Narragansett Bay, L.I. Sound, NJ coastal bays,&
Chesapeake Bay). Targeted sampling in Narragansett Bay, following an August 2002 neap
tide, detected a large area of bottom water below the 2.3 mg/L concentration. A "hybrid"
monitoring design incorporating probabilistic surveys, targeted sampling during periods of
increased water column stratification (neap tides), and moored instrumentation is
necessary to capture the spatial and temporal aspects of DO conditions.