Monitoring the ecological condition of estuaries in the United States
Summers, J.K., Paul, J.F. and Robertson, A. (1995)
Toxicological and Environmental Chemistry, 49, 93-108.
The purpose of the Environmental Monitoring and Assessment Program/Estuaries
component (EMAP-E) is to determine the current status, extent, changes, and
trends in ecological indicators of the condition of the nation's estuarine
resources on a regional and national basis.
Monitoring activities in the Virginian (Mid-Atlantic) and Louisianian (Gulf of
Mexico) Provinces focus on measurements describing the benthic community, the
fish community, water quality, levels of sediment and tissue contamination,
sediment toxicity, wetlands extent/condition, and seagrasses extent/condition.
Estuarine monitoring is based on an EMAP-E probability-based sampling design
conducted over a 60-day period during July-September of each year.
Monitoring activities in the Virginian Province began in 1990 and have
continued annually while monitoring in the Louisianian Province was initiated
in 1991. The results of 1990 monitoring in the Virginian Province show that 20%
of the sediments of the Mid-Atlantic region suffered from poor biological
conditions while 15% of the area showed undesireable conditions in relation to
poor water clarity and the presence of marine debris. In 1991, 31% of Gulf of
Mexico estuarine sediments in the Louisianian Province displayed poor
biological conditions, as measured by benthic community structure, and 32% of
the area was characterized by poor water clarity, the presence of marine
debris, and elevated levels of fish tissue contaminants. Efforts are presently
underway to begin to assess degradation "causes" using statistical
associations among exposure and stressor data for degraded areas in the two
provinces. Monitoring will continue in these provinces, as well as be initiated
in the Great Lakes, in 1992 and monitoring in other areas of the country
(Carolinian Province, Southeast) is scheduled to begin in 1994.