In situ methods of measurement—an important line of evidence in the environmental risk framework

Abstract

A tiered framework provides a structured approach to assess and manage risk and underpins much of the legislation concerning chemicals and environmental management. Management decisions regarding appropriate controls can have high cost implications to the regulated community. The risk framework provides an evidence-based approach to reduce uncertainty in decision making. Traditional assessment is heavily dependent on laboratory-generated toxicity test data and estimations of exposure and effect. Despite many well documented demonstrations of in situ methodologies, they are rarely used by regulators to help improve assessment or to validate risk. Emerging legislation puts greater emphasis on environmental outcomes and represents a significant shift from the reliance on chemical measures alone toward biological responses that improve assessment and demonstrate ecological benefit. Diagnostic methods, that could include in situ-based measures, will help assess and manage environments failing to achieve good status and it is likely that a weight of evidence approach will be needed to help inform management decisions. The potential application of such measures in the risk framework is reviewed in the context of current and emerging legislation concerning chemicals. Effect measures on the basis of in situ methods provide an alternative line of evidence and can help reduce uncertainty in decision making. Criteria are presented to help select appropriate methods in a multiple-line, weight of evidence approach.

A postexposure feeding assay using the marine polychaete Neanthes arenaceodentata suitable for laboratory and in situ exposures

“…In situ toxicity tests have the distinct advantage over the former because they have the potential to provide more accurate assessment of exposure and effects in the field, thus improving the accuracy of management decisions. Detailed accounts of these advantages are provided elsewhere [2][3][4][5][6][7], but they include reduction of artifacts associated with sample manipulation, extraction and storage, exposure under more realistic conditions, and the ability to include time-varying stressors and other site-specific factors in the assessment. Commonly reported disadvantages of in situ bioassays include the loss of control over treatment factors and potential confounding effects associated with predation or competition with indigenous organisms [2,5].…”

An in situ toxicity assay with the local phytoplankton community

“…In spite of this, because of their attractive features, in situ assays are increasingly being recognized as an important line of evidence in reducing uncertainty in risk assessment [1,2,5,6].…”

Adaptive management principles and sediment management

“…Alternatives that perform well are promoted and poorly performing alternatives are adapted or eliminated. Successful adaptive management relies heavily upon well-designed monitoring activities that provide key information for the adjustment of management designs and actions (Wharfe et al 2007).…”