The toxicity of metal mixtures to the estuarine mysid Neomysis integer (Crustacea: Mysidacea) under changing salinity
Verslycke, T.; Vangheluwe, M.; Heijerick, D.; De Schamphelaere, K.; Van Sprang, P.; Janssen, C.R. (2003). The toxicity of metal mixtures to the estuarine mysid Neomysis integer (Crustacea: Mysidacea) under changing salinity. Aquat. Toxicol. 64(3): 307-315. dx.doi.org/10.1016/S0166-445X(03)00061-4 In: Aquatic Toxicology. Elsevier Science: Tokyo; New York; London; Amsterdam. ISSN 0166-445X; e-ISSN 1879-1514, more |  |
| Keywords | Chemical elements > Metals
Chemical speciation
Evolution > Speciation
Fauna > Aquatic organisms > Aquatic animals > Shellfish
Properties > Chemical properties > Salinity
Speciation
Water bodies > Coastal waters > Coastal landforms > Coastal inlets > Estuaries
Mysida [WoRMS]; Neomysis integer (Leach, 1814) [WoRMS]; Neomysis integer (Leach, 1814) [WoRMS]
Belgium, Schelde R. [Marine Regions]; Belgium, Zeeschelde, Galgenweel [Marine Regions]
Brackish water | | Author keywords | combined effects; metal toxicity; mysid; Neomysis integer; salinity; speciation |
| Authors | | Top | | - De Schamphelaere, K., more
- Van Sprang, P., more
- Janssen, C.R., more
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| Abstract | Water quality criteria are mainly based on data obtained in toxicity tests with single toxicants. Several authors have demonstrated that this approach may be inadequate as the joint action of the chemicals is not taken into account. In this study, the combined effects of six metals on the European estuarine mysid Neomysis integer (Leach, 1814) were examined. Acute 96-h toxicity tests were performed with mercury, copper, cadmium, nickel, zinc and lead, and this as single compounds and as a mixture of all six. The concentrations of the individual metals of the equitoxic mixtures were calculated using the concentration-addition model. The 96-h LC50's for the single metals, at a salinity of 5‰, ranged from 6.9 to 1140 µg/l, with the following toxicity ranking: Hg>Cd>Cu>Zn>Ni>Pb. Increasing the salinity from 5 to 25‰ resulted in lower toxicity and lower concentrations of the free ion (as derived from speciation calculations) for all metals. This salinity effect was strongest for cadmium and lead and could be attributed to complexation with chloride ions. The toxicity of nickel, copper and zinc was affected to a smaller extent by salinity. The 96-h LC50 for mercury was the same for both salinities. In order to evaluate the influence of changing salinity conditions on the acute toxicity of metal mixtures, tests were performed at different salinities (5, 10, 15 and 25‰). The 96-h LC50 value (1.49 T.U.) of the metal mixture, at a salinity of 5‰, was clearly lower than the expected value (6 T.U.) based on the non-additive hypothesis, thus confirming the additive effect of these metals in the marine/estuarine environment. Changing salinity had a profound effect on the toxicity of the mixture. The toxicity clearly decreased with increasing salinity until 15‰. Higher salinities (25‰) had no further influence on the 96-h LC50 of the mixture which is situated at a value between 4.4 and 4.6. Finally, the relative sensitivity to the selected metals was compared with the relative sensitivity of the commonly used mysid Americamysis (= Mysidopsis) bahia. |
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