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The NBSP also included the measurement of fluorescent aromatic compounds (FACs)
in bile of demersal fish, as a way to estimate exposure to PAHs, because PAHs are readily
metabolized and excreted (Krahn et al. 1984). The monitoring data on bile FACs that were
generated during implementation of the NBSP has proven to be valuable for use in rapidly
assessing situations such as the emergency response following Hurricane Katrina (Krahn
et al. 2005; Hom et al. 2008). In 1988, the NBSP added measures of CYP1A to other bio-
markers already in use. This biomarker, hepatic activity of aryl hydrocarbon hydroxylase
(AHH), was surveyed by a standardized method (Collier et al. 1995) for several years in
demersal fish from the Atlantic, Gulf, and Pacific coasts of the United States.
Trends analysis throughout the 10 years of the NBSP did not show any monotonic trends
in toxicopathic lesions in any tissues, nor in levels of FACs in fish bile. Interestingly, trends
of increasing hepatic AHH activities were reported for the period from 1988 through 1994,
in winter flounder (
Pleuronectes americanus
) collected at several urbanized sites along the
Northeastern United States (Collier et al. 1998). Although the NBSP was discontinued after
1994, its paradigm (assessing the health of fish from sites showing a range of degrada-
tion by chemical contaminants) was continued in a number of regional monitoring efforts.
Notable among these are the large rivers monitoring network under the U.S. Geological
Survey Biomonitoring of Environmental Status and Trends (BEST) program, and the
PSAMP, which are discussed later in this section.
15.3.2 Environmental Monitoring and Assessment Program
The USEPA's EMAP was one of the first national monitoring programs to use a probabilis-
tic sampling design to monitor the conditions of the nation's waterways, both marine and
freshwater. Field data were collected from 1990 through 2006, generally through a series of
regional efforts conducted in collaboration with local (e.g., state) agencies. Although EMAP
largely focused on chemical analyses and large-scale measures of biological organization,
such as benthic community indices, a biomarker tested in this program was the prevalence
of grossly visible external abnormalities in fish and shellfish. Generally, there was a positive
correlation between increased levels of sediment contamination and these gross pathologies.
In one report from EMAP, almost 25,000 fish were examined, and background prevalences of
abnormalities ranged between 0.5% and 0.7%, whereas prevalences ranged as high as 2-3%
at contaminated sites (Fournie et al. 1996). This is in contrast to histopathological examina-
tion of internal organs of fish, where prevalences of liver lesions have been reported as high
as ~80% for fish from some highly contaminated areas (Malins et al. 1985; Myers et al. 1987).
External pathologies, because of their low resolving power, were dropped from EMAP in the
mid-1990s, and no statistically significant temporal trends in this biomarker appear to have
been reported. On a much smaller scale, EMAP investigators also evaluated splenic macro-
phage aggregates (SMAs), measured by image analysis, for discriminating degraded versus
nondegraded estuaries. Although it was concluded that the number and mean size of SMAs
were effective indicators of chemical contaminants, as well as in some cases of low dissolved
oxygen (Fournie et al. 2001), this biomarker is not currently in widespread use.
15.3.3 Biomonitoring of Environmental Status and Trends
In 1995, the USGS initiated an ambitious effort to determine the effects of environmental
contaminants on fish health in major U.S. river systems, and to use a suite of biomark-
ers to do this. Biomarkers included histopathological examination of several tissues and
hepatic CYP1A (similar to NBSP), but also included measures of reproductive status such
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