Toxicity of seabird guano to sea urchin embryos and interaction with Cu and Pb
Guano is an important source of marine-derived nutrients to seabird nesting areas. Seabirds usually present high levels of metals and other contaminantsbecause the bioaccumulation processes and biotic depositions can increase the concentration of pollutantsin the receiving environments. The objectiv...
| Autores: | , , , , , |
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| Formato: | artículo |
| Estado: | Versión enviada para evaluación y publicación |
| Fecha de publicación: | 2016 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/321347 |
| Acesso em linha: | http://hdl.handle.net/10261/321347 |
| Access Level: | acceso abierto |
| Palavra-chave: | Centro Oceanográfico de Vigo Antagonism Medio Marino Joint toxicity Response surface Sea urchin embryo Seabird guano Trace metals |
| Resumo: | Guano is an important source of marine-derived nutrients to seabird nesting areas. Seabirds usually present high levels of metals and other contaminantsbecause the bioaccumulation processes and biotic depositions can increase the concentration of pollutantsin the receiving environments. The objectives of this study were to investigate: the toxicity of seabird guano and the joint toxicity of guano, Cu and Pb by using the sea urchin embryo-larval bioassay. In a first experiment, aqueous extracts of guano were prepared at two loading rates (0.462 and 1.952 g L-1) and toxicity to sea-urchin embryos was tested. Toxicity was low and not dependent of the load of guano used (EC50: 0.42±0.03 g L-1). Trace metal concentrations were also low either in guano or in aqueous extracts of guano and the toxicity of extracts were apparently related to dissolved organic matter. In a second experiment, the toxicity of Cu-Pb mixtures in artificial seawater and in extracts of guano (at two loadings: 0.015 and 0.073 g L-1), was tested. According to individual fittings, Cu added to extracts of guano showed less toxicity than when dissolved in artificial seawater. The response surfaces obtained for mixtures of Cu and Pb in artificial seawater, and in 0.015 g L-1 and 0.073 g L-1 of guano, were better described by Independent Action model adapted to describe antagonism, than by the other proposed models, according to the Akaike Information Criterion. This implied accepting that EC50 for Cu and Pb increased with the load of guano and with a greater interaction for Cu than for Pb. |
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