Copper complexation by fulvic acid affects copper toxicity to the larvae of the polychaete Hydroides elegans

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 0.19micromol site mg(-1) C, and a logK' 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 EC(50) of 58.9microgl(-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 EC(50) ranging from 55.6microgl(-1) in the no-FA control to 137.4microgl(-1) in the 20mgl(-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.

Acute waterborne copper toxicity to the euryhaline copepod Acartia tonsa at different salinities: Influence of natural freshwater and marine dissolved organic matter

“…In addition, the authors reported that the binding between Cu and fulvic acid was weaker than that between Cu and humic acid. However, the lowest DOM concentration used (8 mg C/L) was considerably higher than the environmentally relevant salt water DOM concentrations tested in the present study, that is, 0.5 mg C/L (SBAT‐DOM) or 2.2 mg C/L (NBAT‐DOM). Therefore, it is possible that these DOM concentrations were not high enough to show a protective effect against the acute Cu toxicity in seawater (salinity 30 ppt).…”

Copper affects biofilm inductiveness to larval settlement of the serpulid polychaeteHydroides elegans(Haswell)

“…(Qiu et al 2007;Xie et al 2005). The results showed that settlement of competent larvae of this species was not affected by relatively short periods (1-2 days) of exposure to high concentrations of Cu (300 mg l 71 ), but with a longer exposure period (3 days) larval settlement was significantly decreased at 100 mg l 71 .…”

“…High concentrations of Cu have led to concern over their harmful impact on the marine environment. Cu stress in many marine invertebrates such as corals (Smith et al 2003), polychaetes (Xie et al 2005;Qiu et al 2007), mussels (Hoare et al 1995), barnacles , sea urchins (Ferna´ndez and Beiras 2001), and ascidians (Bellas et al 2004) has been demonstrated by ecotoxicity bioassays, which are mainly focused on embryos, larvae, juveniles, or adults. The effects of Cu stress on larval settlement, which is the most critical stage in life cycles linking pelagic and sessile life (Pawlik 1992), however, remain largely unexplored.…”

“…The period for subsequent larval development is also short (4-5 days) under optimal conditions (Qiu and Qian 1997). Many studies, therefore, use H. elegans as a test organism in ecotoxicity bioassays to evaluate the impact of heavy metals on the marine environment (Xie et al 2005;Qiu et al 2005Qiu et al , 2007Gopalakrishnan et al 2007Gopalakrishnan et al , 2008. The effect of Cu on H. elegans has been investigated and results show that embryogenesis, larval development, and larvae are highly sensitive to Cu stress (Xie et al 2005;Gopalakrishnan et al 2007).…”

Mining Activities and Associated Environmental Impacts in Arid Climates: A Literature Review

“…Local vegetation near streams and rivers can be impacted when mine waste containing dissolved elements (e.g Cu, Zn, Pb, and As) enters water-bodies (Lewis, 1977;Gammon, 1970;Pagenkopf et al, 1974;Warnick & Bell, 1969). An influx of dissolved trace elements can affect organisms like insect larvae, bivalve mollusks, and microorganisms, which in turn affect larger organisms up the food chain (Wright & Zamuda, 1987;Qiu et al, 2007). As shown in literature (Krishnamurti et al, 2005;Reglero et al, 2008;Moreno-Jimenez et al, 2009), bioaccumulation in local vegetation will directly affect local fauna by the transfer of metals from one organism to another.…”