Document Type

Journal Article

Department/Unit

Department of Biology

Language

English

Abstract

Copper toxicity is influenced by a variety of environmental factors including dissolved organic matter (DOM). We examined the complexation of copper by fulvic acid (FA), one of the major components of DOM, by measuring the decline in labile copper by anodic stripping voltammetrically (ASV). The data were described using a one-site ligand binding model, with a ligand concentration of 0.19 μmol site mg-1 C, and a log K′ of 6.2. The model was used to predict labile copper concentration in a bioassay designed to quantify the extent to which Cu-FA complexation affected copper toxicity to the larvae of marine polychaete Hydroides elegans. The toxicity data, when expressed as labile copper concentration causing abnormal development, were independent of FA concentration and could be modeled as a logistic function, with a 48-h EC50 of 58.9 μg l-1. However, when the data were expressed as a function of total copper concentration, the toxicity was dependent on FA concentration, with a 48-h EC50 ranging from 55.6 μg l-1 in the no-FA control to 137.4 μg l-1 in the 20 mg l-1 FA treatment. Thus, FA was protective against copper toxicity to the larvae, and such an effect was caused by the reduction in labile copper due to Cu-FA complexation. Our results demonstrate the potential of ASV as a useful tool for predicting metal toxicity to the larvae in coastal environment where DOM plays an important role in complexing metal ions. © 2007 Elsevier Ltd. All rights reserved.

Keywords

Copper, DOM, Fulvic acid, Larvae, Speciation, Toxicity

Publication Date

11-30-2007

Source Publication Title

Marine Environmental Research

Volume

5

Issue

64

Start Page

563

End Page

573

Publisher

Elsevier

Peer Reviewed

1

Copyright

Copyright © 2007 Elsevier Ltd. All rights reserved.

Funder

This project was supported by a FRG grant from HKBU to J.W.Q. X.T.

DOI

10.1016/j.marenvres.2007.06.001

ISSN (print)

01411136

Included in

Biology Commons

Share

COinS