Do estuaries pose a toxic contamination risk for wading birds?

Abstract

This version available http://nora.nerc.ac.uk/7676/ NERC has developed NORA to enable users to access research outputs wholly or partially funded by NERC. Copyright and other rights for material on this site are retained by the authors and/or other rights owners. Users should read the terms and conditions of use of this material at http://nora.nerc.ac.uk/policies.html#access This document is the author's final manuscript version of the journal article, incorporating any revisions agreed during the peer review process. Some differences between this and the publisher's version remain. You are advised to consult the publisher's version if you wish to cite from this article. www.springerlink.comContact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trade marks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. AbstractThe impact of potentially toxic chemicals on wildlife is commonly assessed by comparing the intake of the contaminant with the "no observable effects level" (NOAEL) of intake. It is known, however, that there are considerable uncertainties inherent in this method. This study presents a Monte-Carlo based model to assess the degree of risk posed to birds (dunlin, Calidris alpina) from important estuarine habitats, and to show the limitations of such risk assessments, particularly with regard to data availability. The model was applied to predict the uptake of metals (Hg, Pb) Use of lethal toxicity data (LD50/100) was investigated as a method for assessing sub-lethal impacts from Hg. It was found that this method led to a significant under-estimate of the potential impact of Hg contamination, compared with direct estimation of NOAEL.Key words: mercury, lead, probabilistic modelling, estuaries, reproductive toxicity, dunlin.Analysis of uncertainty in environmental risk assessments is becoming increasingly important 3 (e.g. Verdonck et al., 2005). To our knowledge, however, modelling approaches have not yet 4 been developed for the assessment of uncertainty in contaminant uptake and risk in wading 5 birds. Here we present a probabilistic modelling approach for risk assessment that employs 6 ecologically relevant toxicological endpoints and, crucially, data inputs (bird behaviour, 7 metal content of prey items, toxicity endpoints) that are realistic for typical environmental 8 impact assessments. The Monte-Carlo based model is used to assess the degree of risk posed 9 to birds from important estuarine habitats, and to show the limitations of such risk 10 assessments, particularly with regard to data availability. 11 12 Estuaries are typically important feeding areas for wading birds but are also often subject to 13 historic and current chemical contamination by heavy metals. Estuarine sediments 14 commonly form major sinks for contaminants released during industrial activity. Many 15 industrial processes lead to the release of metals initially in solution, which can then be 16 adsor...

The intertidal wetlands of southern Jiangsu Province, China – globally important for Spoon-billed Sandpipers and other threatened waterbirds, but facing multiple serious threats

“…Chemical discharges (deliberate or accidental) can pollute the coastal environment (Melville 2015) and may kill benthic organisms (Li and Daler 2004), thereby potentially affecting availability of food for waterbirds. Chemical pollutants may also be directly toxic to birds and may bioaccumulate through the food chain (Smith et al 2009). Although there is currently no evidence of a direct impact of environmental pollution on waterbirds in Jiangsu, waste water discharged from the Xiao Yangkou chemical industry complex in Rudong County is reported to have led to a decrease in benthic organisms on the adjacent intertidal flats (Qing and Song 2015).…”

Mercury Dynamics in a San Francisco Estuary Tidal Wetland: Assessing Dynamics Using In Situ Measurements

“…Mercury (Hg) accumulation in estuarine food webs is of concern because high tissue concentrations in fishes and birds (Mason et al 2006;Eagles-Smith and Ackerman 2009;Smith et al 2009) have been associated with neurological and behavioral abnormalities, low reproductive success, and direct toxicity (Adams and Frederick 2008;Mitro et al 2008;Crump and Trudeau 2009). Estuaries are particularly vulnerable to Hg contamination because they are often the receiving water bodies for sedimentary fluxes of mercury from upland areas.…”

A brief review on models for birds exposed to chemicals

“…A bit less than one third of the papers investigated drugs, while around 20% of them focused on PPP (Figure 3, lower panel). Regarding trace metallic elements, mercury and derivatives have been the most studied (Smith et al, 2009;Nichols et al, 2010;Jackson et al, 2011). Exposure routes, all chemical substances combined, covered the full range of bird feeding regimes via their food sources.…”