Uncertainties in Sediment Quality Weight-of-Evidence (WOE) Assessments

Abstract

Uncertainties in sediment quality assessments are discussed in five categories: (1) sediment sampling, transport and storage; (2) sediment chemistry; (3) ecotoxicology; (4) benthic community structure; and (5) data uncertainties and QA/QC. Three major exposure routes are considered: whole sediments, and waters in sediment pores and at the sediment-water interface. If these uncertainties are not recognized and addressed in the assessment process, then erroneous conclusions may result. Recommendations are provided for addressing the identified uncertainties in each of the key areas. The purpose of this paper is to improve the reporting of sediment quality assessments.

Review of the reproductive biology of amphipods and their endocrine regulation: Identification of mechanistic pathways for reproductive toxicants

“…Assessments conducted with these databases in conjunction with field validation studies involving contaminated sediments suggest that SQGs are reasonable predictors primarily of acute effects or no effects on benthic organisms. However, several limitations have been observed regarding the use of SQGs in sediment quality assessments [10,11]. One concern is the capability of SQGs to predict adequately the presence or absence of chronic toxicity to sediment-dwelling organisms in field-collected sediments.…”

Recolonisation of translocated metal-contaminated sediments by estuarine macrobenthic assemblages

“…The present study demonstrated that defaunated sediments sourced from locations with high trace metal concentrations were colonised by different faunal assemblages to sediments sourced from a location with lower concentrations. While no single approach can provide a confident and robust assessment of the ecological status of a location, when coupled with field surveys and/or toxicological data, manipulative translocation experiments provide an additional line of ecological information which can be integrated into a weight-of-evidence approach for assessing the risks associated with contaminated sediments (Batley et al 2002). The translocation technique used in this experiment is simpler and more accurate than spiking with a complex mixture of contaminants, and incorporates other chemicals which may not have been foreseen.…”

“…As benthic communities are continually modified by numerous abiotic and biotic processes, the correlative models that underpin many of these studies (survey and gradient) do not permit a direct link to causality (Luoma 1996). The influences of natural variability, sampling error, and additional (often unidentified) contaminants can also confound the findings of survey studies, reducing our ability to confidently identify and assess the ecological risks associated with a particular location (Suter and Barnthouse 1993; Batley et al 2002).…”

Use of Data on Contaminant/Sediment Interactions to Streamline Sediment Assessment and Management

“…However, sediment guidelines and their derivation methods are still controversial, and their appropriateness should be carefully evaluated in terms of site management goals, study questions, and the CSM. Two recent documents that address the use of SQGs and weight-of-evidence frameworks are Chapman et al (2001) and Batley et al (2002). A recent Pellston workshop addressed this issue.…”