The Coastal Resource Coordinator's Bioassessment Manual

HAZMAT 93-1 Role of Bioassessment
CHAPTER 2
THE ROLE OF BIOASSESSMENT IN THE REMEDIAL
PROCESS
INTRODUCTION
The selection of the appropriate bioassessment procedure(s) is dependent on the objectives
of the particular stage in the remedial process. The amount of information required to make
necessary decisions regarding further activities at the site tends to increase as the overall
assessment of a site proceeds from the preliminary screening to the endangerment
assessment and selection of remedial action. Regardless of the stage in the remedial
process, it is of primary importance to clearly establish the intended application of
bioassessment data prior to such data collection, including the specific questions that are
being addressed, the proposed decision criteria, and appropriate sampling strategy and
statistical design. If properly planned, data collected at each stage can be used to guide the
development of work plans for subsequent stages. The early incorporation of an overall
sampling design that adequately addresses the potential risks to natural resources reduces
the possibility of additional sampling later that might delay or hinder the remedial process.
The role of bioassessment approaches during the different stages of a site remediation is
discussed in more detail in this chapter.
PRELIMINARY ASSESSMENT
The data needs for the preliminary assessment are usually directed toward broad-scale
screening for evidence of release of contaminants to the environment and the presence or
absence of toxicity. Bioassessment procedures, particularly bioaccumulation studies and
toxicity tests, can play an important role in site screening.
The bioaccumulation of chemical contaminants in tissues of resident organisms effectively
demonstrates the bioavailability of contaminants associated with the site. For contaminants
known to bioaccumulate to a greater extent in higher trophic level organisms (e.g., PCBs,
mercury), determining the degree of contamination in a representative higher trophic level
organism may provide a worst-case evaluation appropriate for the preliminary assessment.
Combined with information on the site history, visual observations of site characteristics
and chemical analyses, toxicity tests can provide qualitative information on the distribution
2-1 July 2003