Variations in the Microcystin Content of Different Fish Species Collected from a Eutrophic Lake

Justine Schmidt,Mylynda Shaskus,Roman Khidekel,Carl Oesch,Gregory Boyer,John Estenik

doi:10.3390/toxins5050992

Justine Schmidt, Mylynda Shaskus + Show 4 more

Open Access

https://doi.org/10.3390/toxins5050992

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Abstract

Microcystins produced from cyanobacteria can accumulate in fish tissues. Liquid chromatography coupled with tandem quadrupole mass spectrometry (LC-MS/MS) is an attractive alternative to immunoassays for the determination of low concentrations of microcystins in tissues. Fish taken from Grand Lake St. Marys, a eutrophic lake in Ohio, USA, were analyzed for microcystin-LR in their fillets using LC-MS/MS. Of 129 fish tested for microcystins, only black crappie (Pomoxis nigromaculatus) and common carp (Cyprinus carpio) tested positive for microcystin-LR. Less than 10% of Pomoxis and 7% of Cyprinus samples contained measurable levels of microcystin-LR. Statistical analysis yielded a p-value of 0.07 between Pomoxis and the pooled results of the other four fish species. However, this comparison was complicated by the large difference in sample size between species. Further sampling in Grand Lake St. Marys for microcystin-LR would help determine if microcystin-LR exposure occurs through foodweb transfer.

Highlights

Cyanobacteria can proliferate in marine and freshwater bodies with high nutrient loads [1,2]
The current study suggests that Pomoxis nigromaculatus is more at risk for microcystin contamination than other species of fish
There may be a difference in microcystin-LR content in the tissues of fish based upon species

Summary

Introduction

Cyanobacteria (blue-green algae) can proliferate in marine and freshwater bodies with high nutrient loads [1,2]. Microcystin-LR is a monocyclic peptide hepatotoxin produced by cyanobacteria and is the most common variant of the larger family of related toxins collectively called microcystins [8]. These toxins impact liver tissue in organisms and cause cell damage and death through inhibition of protein phosphatases [9]. Tissue samples are routinely cleaned up prior to analysis using techniques such as solid phase extraction (SPE), or extraction with a non-polar solvent to remove lipids (Table 1). We use a charcoal purification step with liquid chromatography with multiple reaction monitoring of a quantitation transition and four individual confirmation transitions

Results and Discussion

Experimental Section

Conclusions