Dec 1, 2017

Levels of Microcystins in Fish from Lake Erie and the Impacts on Humans Consuming Contaminated Fish

LIsa Rivers '18

Because of the excessive amounts of pollution and nutrient influx from sustained human activities, a variety of toxins produced by harmful algal blooms (HABs) have increased in frequency and severity and have incorporated their way into aquatic species and humans (Peng et al., 2010). These cyanobacterial toxins and their wide range of adverse effects on several marine species are now becoming widely noticed such as paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), and fish kills due to loss of food sources and anoxia (Anderson et al., 2008). The most common and dangerous of these toxins are microcystins, causing tumors and liver disease in animals and humans from long term exposure to contaminated drinking water and food products (Zhang et al., 2009). In fact, intake of microcystins in humans from both drinking water and the consumption of fish at the top of the food chain is the current focus of researchers today (Xie et al., 2008). However, to protect human health, more research is required because less is known about how humans are impacted from eating microcystin-contaminated fish muscle. Therefore, I will be examining how microcystins accumulate in the muscle tissue of two piscivorous and two planktivorous fish from three regions of Lake Erie with varying trophic states. From there, I plan to conduct a public health survey among those who live within 100 km from the coastline of Lake Erie and consume fish on a regular or semi-regular basis to see if I can find any significant correlation.

Is Death the End? A Glimpse into the Decomposition Microbiome Structure

Tracy Zeien '18

In the forensic field, it is important to determine the estimated time that a person has ceased to live. This time marker can aid in the identification of the individual, provide evidence, or is employed to verify an alibi during an investigation. Postmortem Interval (PMI), the time between death and discovery, can be estimated by gross taphonomic characteristics and is dependent on internal and external factors. Livor, Algor, and Rigor mortis have been extensively researched and can be accurately estimated to occur during a certain amount of time after the heart stops beating. Bacteria that reside in our bodies, aid in our digestive system and they also are essential to breaking down our organic tissues. However, little is known about the biodiversity of the bacterial community structure during the decomposition process. This

study targeted the bloat stage of decomposition and the bacterium that participate during putrification. Two cadavers were allowed to naturally decompose at the Southeast Texas Forensic Science facility. Both bodies were sampled prior to, and after, the bloat stage of decomposition. Pyrosequencing of the 16S rRNA gene was used to analyze the samples. A shift from aerobic to anaerobic bacterium was observed at each sample site. Because of the small sample size for this experiment, this data is intended to be preliminary input for future data sets. The authors of the report advised that more studies be conducted to better understand the essential role of bacteria for the decomposition process.