Harbour sediment

Includes river, lake, marine, and harbour sediments. 

Marine sediments, estuarine sediments, freshwater pond sediments, harbour sediments, stream sediments, lake sediments... 

Given the eomplexity of eontaminated sediments, rationally ehosen and applied bioassays and bioindieators for hazard, risk and impaet assessment are needed that ean prediet and deteet the biologieal effeets of eontaminants in eombination with ehemieal analyses (Chapman and Mann, 1999). This thesis foeuses on the applieability of in vitro and and in vivo bioassays and bioindieators as tools for evaluating the effeets of eomplex ehemieal mixtures in the proeess of deeiding whether dredged harbour sediments ean be safely disposed of at sea. To this end three objeetives have been defined ... 

This thesis focuses on the applicability of in vitro, in vivo bioassays and bioindicators as tools for evaluating the effects of complex chemical mixtures in the process of deciding whether dredged harbour sediments can be disposed of at sea without serious adverse effects on marine ecosystem and human health. It considers the North Sea delta area in order to determine a comprehensive approach for the application of both in vitro and in vivo bioassays for hazard assessment, advanced risk assessment, and location-specific ecological impact assessment for dredged harbour sediments. To aid in the selection of appropriate, robust and reliable in vitro and in vivo bioassay and bioindication methods for these specific purposes, the uneertainty, predictability and specificity of the bioassays have been explored and the applieability in eombination with other analyses is discussed. The focus of the chosen examples is on bioassays and bioindicators for the relatively well studied dioxin-like contaminants and TBT. 

Chapter 5 illustrates a site-specific impact assessment of TBT originating from antifouling paint and present in marine as well as harbour sediments. TBT is an endocrine-disrupting chemical and extremely toxic to marine life such as gastropod species where it causes intersex and population decline. 

The Port of Amsterdam transect yielded four locations in the estuarine system with highly polluted sediment (sites 1,9, 10 and 11). The chemical concentrations there were higher than at the sites in the Port of Rotterdam transect (Table 4a). PCB and trace metal concentrations in Rotterdam harbour sediments and TBT, triphenyltin (TPhT) and PAH concentrations in all sedi-... 

The A. marina bioassay is routinely used in the UK, but only in more saline conditions (Thain and Bifield, 2001). The survival of this polychaete in our study was hardly affected by the sediments tested during the study, but the number of casts produced varied considerably (Table 6). Significant effects with the above sediment in vivo bioassays used here have been demonstrated in other studies, not only in Dutch harbour sediments, but also marine and estuarine environments (Matthiessen et ah, 1998 Kater et al., 2001 Stronkhorst, et al., 2003b). 

Table 2 Action levels (AL) applied in the Chemical Toxicity Test (CTT) system to judge whether dredged material from Dutch harbours can be disposed at sea. Underlined values exceeds the AL threshold. The three bioassays in the marked Box are evaluated in Table 3. Loswal Noord is the Reference station where harbour sediments are dumped. 

Application of bioassays for hazard, risk and impact assessment of dredged harbour sediments... 

For specific situations, a full ecotoxicological risk assessment could be performed for disposal of dredged harbour sediments. For example, when there are indications for the need for additional toxicity testing or when the outcome of the basic testing (Box A) is not sufficiently... 

Table 4 Summary of the uses of bioassays for hazard, risk and impact assessment of dredged harbour sediments to be disposed of at sea explained in Figure 3 (Boxes A, B and C). Chemical analyses are mentioned in italics.

Currently usedfor licensing disposal harbour sediment rapid screening In vitro bioassay DR-Luc (purified extract) Chemical analyses (PAHs, PCBs, toxic metals, TBT) chemical anal.) In vivo bioassays with cultured or wild species... 

Currently Advanced risk assessment harbour sediment before disposal In vivo bioassays with cultured species ecologically relevant endpoints growth Development, survival, reproduction PAF or msPAF In vivo bioassays with wild species... 

Table 6 Dioxin-equivalents (TEQs) determined with an in vitro bioassay (DR-Luc) in dredged harbour sediments, marine sediment, and suspended matter from the Dutch coastal zone and estuaries of the North Sea...

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