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University of Michigan Biological Station

The University of Michigan Biological Station (UMBS) was founded in 1909.

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Quantification of Microcystin-LR among Fish Species in an Oligotrophic Lake: A Proposed Study in Little Traverse Lake, MI.

Aquatic
Project Abstract: 
Cyanobacterial blooms are increasing in frequency, which consequently has led to increases in harmful cyanotoxins such as microcystin. Microcystin is harmful to human health if ingested, and exposure via fish consumption is a current route of interest (Ibelings and Chorus, 2007). Most research has focused on microcystin concentrations in eutrophic lakes, however studies indicate that microcystin concentrations can be significant in oligotrophic lakes (Carey et al., 2012). Thirty five perch and thrity five blue gill will be sampled both before and after the cyanobacterial bloom during the summer 2014 from Little Traverse Lake(an oligotrophic lake).Muscle tissue will be analyzed for microcystin concentrations using an Enzyme Linked Immuno Sorbent Assay (ELISA).Concentration values will be used to determine conservative consumption guidelines, using the World Health Organization (WHO) standards, and treating ELISA readings as microcystin-LR equivalents.
Investigator(s): 
Heather Snyder
Status of Research Project: 
Complete (archive)
Years Active: 
2013
Methods: 
Sampling Thirty five perch and thirty five blue gill will be caught with hook and line both before and after the seasonal cyanobacterial bloom. Specific dates will need to be determined closer to the proposed sampling time, because bloom outbreaks are temperature dependent. All samples will be frozen on ice and will be cleaned and gutted within 48 hours of capture. One filet and the liver will be kept from each fish sample, wrapped in foil and frozen prior to chemical analysis. Chemical Analysis Muscle tissue from each sample will be analyzed with Enzyme Linked Immuno Sorbent Assay (ELISA) by the UM Biological Station’s analytical chemist, Jennifer Croskrey. ELISA determines the total quantity of the microcystin congeners LR, RR, YR, LA, and nodularin present, however the cross reactivity between the different structural variants inhibits the differentiation between congeners. While the total quantity of microcystin is a useful metric by which to determine harmful exposure, the current WHO advisories are expressed as microcystin-LR equivalents. In order to determine what proportion of the total microcystin is the congener microcystin-LR we propose running ten High Performance Liquid Chromatography (HPLC) tests on randomly selected samples that were also analyzed with ELISA. The HPLC tests will be run by Rick Rediske at the Annis Water Resources Institute, Grand Valley State University, in Muskegon. Statistical Analysis Using mean weights for predetermined age categories established by the Center for Disease Control along with the WHO advisory of 0.04 µg MC kg body weight -1, we will calculate the mean quantity of each fish species that can be safely consumed. Additionally, we will run a two sample t-test to determine difference in microcystin content between fish species. Pearson’s correlation coefficient will also be used to determine if a size- microcystin concentration relationship exists. Finally, we will run regression analyses to compare samples analyzed by ELISA and HPLC analysis. By plotting the total microcystin concentration from the ELISA test, against the microcystin-LR concentration from the HPLC test we hope to determine an equation to predict quantity of microcystin-LR from the total microcystin concentration.