Published: Apr 1, 2015
Last Modified: May 19, 2016
Length: 21 pages
Abstract
Cyanobacterial harmful algal blooms (HABs) degrade water quality of western Lake Erie and create negative economic impacts on an annual basis. Public health is at the forefront of concern because these blooms are often toxic due to an abundance of Microcystis. This genus of cyanobacteria produces the toxin microcystin, which causes gastrointestinal illnesses, damages the liver, and is capable of promoting tumors or death of animals (Poste et al 2011). The World Health Organization (WHO) has set values for microcystin in drinking water, recreational contact, and total daily consumption, but no standards exist for concentrations of microcystin in food. Because microcystin can accumulate in fish tissues, and fishing and fish consumption are important economic and cultural practices in Lake Erie, there is a potential health risk to humans via consumption of fish inhabiting waters with high concentrations of microcystin.
Walleye is one of the most significant sportfish of Lake Erie, and a previous study found this species can have greater microcystin concentrations than yellow perch and white perch studied in the same time period (Wituszynski 2014). For these reasons, this study quantified microcystin levels in walleye tissue using an enzyme-linked immunosorbent assay (ELISA) and compared to public health thresholds used by the Ohio Department of Natural Resources (ODNR). Samples were harvested at different times and from locations in attempt to understand the seasonal correlation between bloom intensity and microcystin concentration, and impacts of variations in bloom intensity at different locations. The effects of chronic exposure of fish to microcystin has not been widely studied for Lake Erie, and no studies presently exist which have examined year-to-year variation in microcystin content in fish. Thus, by comparing this study to a similar study conducted in 2013 (Wituszynski 2014), we can aid in identifying correlation between annual variation in HABS, determine if previous exposure has an effect on accumulation in fish, and understand when microcystin concentrations in fish tissues may be at its peak when compared to HAB intensity.
