Mt. Barbour et al., Measuring the attainment of biological integrity in the USA: a critical element of ecological integrity, HYDROBIOL, 422, 2000, pp. 453-464
The concept of ecological integrity has become a worldwide phenomenon and i
s firmly entrenched into the regulatory structure of environmental law in t
he United States of America (USA). The attainment of ecological integrity r
equires the attainment of its three elements: physical, chemical, and biolo
gical integrity. In the USA, measures of chemical integrity were implemente
d first into monitoring programs and were effective in reducing pollutant l
oadings to the nation's surface waters. Because biological communities inte
grate the effects of different stressors such as reduced oxygen, excess nut
rients, toxic chemicals, increased temperature, excessive sediment loading,
and habitat degradation, the advent of bioassessment in regulatory program
s has provided a more comprehensive and effective monitoring and assessment
strategy. Measures of biological integrity clearly have become a priority
in the USA. The development of biological criteria (biocriteria) within reg
ulatory programs to serve as thresholds by which to judge the attainment of
designated aquatic life conditions of surface waters is a major focus of s
tates and Indian tribes within the USA. The derivation of reference conditi
ons for the nation's surface waters (i.e., streams, rivers, lakes, wetlands
, estuaries, and marine waters) across different physiographic regions is a
critical element in the design of biocriteria and is currently a primary i
nitiative in the USA. Nearly all state water resource agencies have develop
ed bioassessment approaches for streams; 1600 to 75 000 km of streams requi
re assessment in each state. Bioassessment development for other water body
types is not as advanced to date. The US Environmental Protection Agency (
USEPA) has produced technical guidance for developing effective bioassessme
nt programs; they include crucial elements such as defining objectives, cla
ssifying water bodies according to expected biological attributes, deriving
the reference condition of the site classes, developing standardized proto
cols for sampling and data analysis, and implementing a quality assurance p
lan. Approaches to bioassessment in the USA follow a basic design of incorp
orating various attributes of the elements and processes of the aquatic com
munity, which is either an aggregation into a multimetric index or a series
of multivariate analyses using the attributes as input variables. The Clea
n Water Act of 1972 and its subsequent amendments mandate maintaining, rest
oring, and protecting the ecological integrity of surface waters. Through u
se of robust bioassessments and other measures of ecological integrity, the
USA has developed a strategic plan to establish priorities to meet this go
al.