Bioaccumulation of microcystins by fish associated with a persistent cyanobacterial bloom in Lago de Patzcuaro (Michoacan, Mexico)
| Autor: | Katherine Walton, Fernando W. Bernal-Brooks, Alan E. Wilson, Elisha Lee, John P. Berry |
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| Rok vydání: | 2010 |
| Předmět: |
Cyanobacteria
biology Microcystins Ecology Health Toxicology and Mutagenesis Fishes Zoology Enzyme-Linked Immunosorbent Assay Fresh Water biology.organism_classification Cyprinus Bioaccumulation Environmental Chemistry Goodea Animals Humans Chirostoma Bloom Carp Water Microbiology Mexico Water Pollutants Chemical Trophic level |
| Zdroj: | Environmental toxicology and chemistry. 30(7) |
| ISSN: | 1552-8618 |
| Popis: | Lago de Patzcuaro is a historically important freshwater fishery in Mexico. The lake is presently characterized by a persistent bloom of cyanobacteria, specifically dominated by recognized producers of toxic microcystins (MCYSTs). We evaluated MCYSTs in sestonic and dissolved fractions of the water column, as well as representative fish species (silversides, Chirostoma spp.; Goodea sp.; and carp, Cyprinus carpio) obtained from local markets and small commercial catches during the bloom. Samples were evaluated primarily by enzyme-linked immunosorbent assay (ELISA), and secondarily by protein phosphatase (PPase) inhibition assay and liquid chromatography-mass spectrometry (LC-MS). Sestonic MCYST concentration (0.02-0.36 µg/L) generally correlated inversely with distance from the bloom, supporting the bloom as the source of the toxin. Several MCYST variants, including MC-LR, -LA and -LY, as well as didemethyl variants, were identified by LC-MS/MS analysis. All three species of fish bioaccumulated MCYSTs in relevant tissues, and toxin content correlated with trophic level, with highest and lowest levels measured in phytoplanktivorous and zooplanktivorous representatives, respectively. Detection of MCYST in silversides and Goodea sp. is particularly relevant because both are consumed in their entirety, including viscera (e.g., liver) known to primarily accumulate MCYST. These results indicate that Lago de Patzcuaro is indeed characterized by a toxigenic bloom, and that commercially important fish species from the lake accumulate toxic MCYST in tissues relevant to human consumption. As such, this system may represent an ideal model of the trophic transfer of MCYSTs and its relevance to human and environmental health. |
| Databáze: | OpenAIRE |
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