Lyngbya wollei is a filamentous cyanobacterium which forms large nuisance mats and has infested eastern and southeastern U.S. Lakes and reservoirs for over 100. years. Lyngbya was recently identified in the Great Lakes system in the St. Lawrence River, and Western Lake Erie. Here we report on large deposits of L. wollei washing onshore at a popular recreational beach in Lake Saint Clair, part of the Great Lakes system. The amount of L. wollei deposited on shore was quantified and evaluated for the presence of fecal indicator bacteria (FIB). High concentrations of Escherichia coli, enterococci and Clostridium perfringens were found in the L. wollei in nearshore waters. The densities of E. coli (MPN), enterococci (MPN) and C. perfringens (CFU) attached to L. wollei averaged 3.5, 3.2 and 3.2. log/g, respectively. In contrast, nearshore waters contained nearly 10 times less FIB, averaging 2.6, 2.4 and 2.6. log/100. ml of E. coli (MPN), enterococci (MPN) and C. perfringens (CFU), respectively. DNA fingerprint analysis was used to examine the population structure of E. coli isolates obtained from L. wollei mats. The L. wollei-borne E. coli strains were genetically diverse, suggesting a causal relationship between E. coli and L. wollei. Results from this study indicate that in addition to the macroalga such as Cladophora, cyanobacteria like L. wollei also harbor FIB, potentially impacting water quality and human health in the Great Lakes.
Bibliographical noteFunding Information:
This project was funded through Wayne State University, Department of Biological Sciences . We thank Krystal A. Bakkila and Brittanie L. Dabney for their generous help in field work and sample processing. We also thank Murulee Byappanahalli and Richard L. Whitman with USGS Great Lakes Science Center, for species identification and valuable suggestions, Brian Badgley for help with diversity calculations, Cathy Darnell for providing graphical assistance, and Eric Anderson with the Cooperative Institute of Great Lakes Research for providing valuable suggestions.
- E. coli population structure
- Fecal indicator bacteria
- Great Lakes
- Lyngbya wollei