Department of Environmental Studies, Alma College, Alma, MI, 48801, USA.
Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, M5S 3B2, Canada.
Environ Monit Assess. 2020 Mar 5;192(4):216. doi: 10.1007/s10661-020-8168-7.
The Pine River, in the central, Lower Peninsula region of Michigan, has a long history of contamination. Livestock facilities and manure application sites along the Pine River and its tributaries have led to elevated nutrient levels. In addition to nutrient loading and associated low levels of dissolved oxygen, the presence Escherichia coli bacteria have caused environmental and human health concerns. According to the Michigan Department of Health and Human Services, and the Michigan Department of Environment, Great Lakes, and Energy, E. coli counts in summer months consistently have exceeded safe levels for human contact since 2005. Though it is recommended that residents do not swim in the Pine River, there are no specific restrictions on recreational fishing which is prevalent. Few studies have evaluated whether or not E. coli accumulates in the mucus of fish and, if so, whether that provides a viable route of E. coli exposure for anglers. This study first evaluated the presence of fecal coliform and E. coli bacteria on hatchery-raised caged fish placed in the river as well as resident fish. Results showed that fecal coliform and E. coli bacteria accumulated both on caged and resident fish. This result led to further testing showing E. coli to be found on anglers' hands whether or not they handled or interacted with resident fish. This study suggests that fishing in rivers with heavy bacterial loading from agricultural runoff may expose anglers to potentially harmful E. coli.
密歇根州下半岛中部的派恩河（Pine River）历史上一直受到污染。派恩河及其支流沿岸的牲畜养殖场和粪肥施用地导致了营养物质水平的升高。除了营养物质负荷和相关的低溶解氧水平外，大肠杆菌（Escherichia coli）细菌的存在也引起了环境和人类健康问题。密歇根州卫生与公众服务部和密歇根州环境、五大湖和能源部表示，自 2005 年以来，夏季大肠杆菌计数一直持续超过人类接触的安全水平。尽管建议居民不要在派恩河中游泳，但这里仍普遍存在着不受限制的娱乐性捕鱼活动。很少有研究评估大肠杆菌是否会在鱼类的黏液中积累，如果是这样，这是否为钓鱼者提供了一条可行的大肠杆菌暴露途径。本研究首先评估了在河里放置的养殖笼养鱼和当地鱼类上粪便大肠菌群和大肠杆菌的存在情况。结果表明，粪便大肠菌群和大肠杆菌都在笼养和当地鱼类上积累。这一结果促使进一步的测试表明，无论钓鱼者是否接触或与当地鱼类互动，他们的手上都会发现大肠杆菌。本研究表明，在受到农业径流严重细菌污染的河流中钓鱼可能会使钓鱼者接触到潜在有害的大肠杆菌。
