The Impact of Wastewater Effluent on the Carapace Microbiome of an Invasive Crayfish in an Urban River.

Microbial communities are ubiquitous and highly variable in aquatic environments, especially within urbanized waterbodies routinely exposed to effluent, runoff, and other forms of anthropogenic pollution. The North Shore Channel (NSC) is a drainage canal connecting Lake Michigan to the North Branch of the Chicago River that receives effluent from a wastewater treatment plant (WWTP). The NSC contains a large population of red swamp crayfish (Procambarus clarkii), a globally known and harmful invader. The high density of red swamp crayfish below the WWTP represents a potential vector for spreading pathogenic bacteria from the effluent to humans and other aquatic species. We collected bacterial communities from crayfish carapaces, sediment, and water, each from above and below the WWTP. We analyzed these communities using a 16S rRNA sequencing approach. We calculated the Shannon diversity index for each sample and grouped samples based on their distance from the WWTP. We performed ANOVA for each sample type between the upstream samples and two groups below the WWTP. Crayfish and water samples showed a significant relationship between alpha diversity and distance from the WTTP (p-value < 0.001), while sediment samples did not have a significant relationship (p-value 0.613). We also identified several genera within the crayfish samples that are known to contain pathogens. Our results show that the WWTP is a major factor driving the diversity within the carapace bacterial communities of red swamp crayfish in the North Shore Channel.

Primary Presenter: Grant Dlesk, Loyola University Chicago (gdlesk@luc.edu)

Authors:

Grant Dlesk, Loyola University Chicago  (gdlesk@luc.edu)

Reuben Keller, Loyola University Chicago  (rkeller1@luc.edu)