Development and assessment of methods for quantifying microcystins in fish tissues

Manjunath Manubolu, postdoctoral associate, Osmania University (India)
Stuart A. Ludsin, faculty mentor

Background

• Hometown: Thirupati, India
• Degrees received: PhD in biochemistry, Sri Venkateswara University, Andhrapradesh, India

What is the issue or problem addresses in your research?

Harmful algal blooms dominated by cyanobacteria (cyanoHABs) have increased in aquatic ecosystems worldwide, owing to human-driven eutrophication (i.e., nutrient pollution), with their prominence expected to increase with continued climate change. These cyanoHABs produce toxins, which can accumulate in the food web, including in the edible (muscle) tissues of fish harvested by humans for their consumption.

What methodology did you use in your research?

To begin to fill these information gaps, we have been improving methods to extract and measure MCs in fish tissues, and quantifying MC levels across the cyanobacteria bloom season in Lake Erie's two most important sport and commercial fishes (i.e., walleye and yellow perch). More specifically, we have developed an optimized ultra-performance - liquid chromatography - tandem mass spectrometry (UP-LC-MS/MS) method to reliably quantify eight of the most toxic variants of MC in fish tissues.

What are the purpose/rationale and implications of your research?

We have developed precise, accurate, and sensitive methods to quantify individual and total MC concentrations in fish tissues. Since 2015, our methods have been used to quantify MC concentrations in Lake Erie walleye and yellow perch before, during, and after the cyanobacteria bloom season, the results of which are currently being used by Ohio agencies to set fish consumption guidelines during the cyanoHAB season, as well as to guide future monitoring.