Environmental Analysis Tools - Environmental Impact Analysis: Process and Methods - page 270

In contrast, there is frequently reluctance on the part of the ecological risk
assessor and the overseeing agency ecologist as well, to assign assessment
endpoint status to invertebrates, plants, and other ecological units low on
the food chain and visibility spectrum. The reluctance is an effort to avoid
the criticism and bad publicity: “I'm being forced to spend millions of dollars
and sacrifice thousands of jobs to protect some insect?” However, protection
of such resources can be incorporated into the ecological risk assessment by
other means, and the other ecological endpoint, the measurement endpoint,
affords an opportunity to protect resources that do not have the status and
publicity of charismatic mega fauna. But these endpoints have to be closely
linked to the assessment endpoint so that the need for remediation can be
expressed based on a popular ecological attribute warranting protection
rather than an unrecognizable ecological characteristic such as the number
of seeds produced by an obscure plant species. Guidelines and criteria have
been established for the selection of endpoints based on site conditions and
contaminants present (U.S. EPA 1989f, Maughan 1993, Suter et al. 2000).
As pointed out above, assessment endpoints typically represent very visible
attributes with a high public-interest value. However, directly measuring the
health and sustainability of one of these popular attributes can be a daunting
task. For example, to measure the density and health of a salmon population in
a specific river would require following the fish through several years as they
matured and returned to breed. It would also necessitate sampling and survey
during multiple seasons and life stages as they breed, mature past the juve-
nile stage, out-migrate, and return to spawn. This would take years, untold
resources, and delay any cleanup action beyond any reasonable expectation.
As a substitute to a lengthy and complex evaluation of broadly expressed
assessment endpoints, measurement endpoints were developed to indicate,
rather than measure directly the status of the assessment endpoints.
Measurement endpoints typically represent single requirements or condi-
tions necessary for the survival and health of the assessment endpoints. These
simpler attributes can be easily measured and usually quantified within
the scope, budget, and time frame of a hazardous waste site evaluation and
cleanup. However in most cases, it is necessary to identify multiple measure-
ment endpoints to gauge the status of the assessment endpoint. In the above
salmon population example, at a minimum it is essential that endpoints
reflect the chemical suitability of the water (i.e., water-quality standards and
criteria) and the condition of the substrate where the fish require gravel nests.
Endpoints would also be required to evaluate the food available to the matur-
ing salmon to ensure their health and continued survival. This is where the less
visible and popular ecological attributes enter into the ecological risk assess-
ment, as the health of the aquatic invertebrates and forage fish segments of the
aquatic community are designated as measurement endpoints. In the initial
problem formulation phase, the measurement endpoints are often general and
non-site-specific, but are refined at a later stage of the assessment if the degree
of risk is deemed uncertain after the screening-level ecological risk assessment.