Man-made filtration systems often do a great job of protecting human health, but natural filtration systems can be equally if not more impressive than the ones people devise. Anodonta californiensis, a threatened mussel species, has shown its value as a filtration system that removes E. coli bacteria as water flows through it, according to Chemical and Engineering News.
Reintroducing a threatened freshwater mussel species to streams and estuaries could help remove harmful bacteria from the water, according to a new laboratory study (Environ Sci. Technol. 2015, DOI: 10.1021/es5033212).
The findings suggest that increasing mussel numbers could improve not only ecosystems, but also human health, says David C. Love, an environmental health scientist at Johns Hopkins University. The data are “yet another reason to want more shellfish restoration in our local streams, rivers, and estuaries,” says Love, who wasn’t involved in the study.
Unfortunately, numbers of many bivalve species are dwindling across the U.S. because of habitat destruction, threats from invasive species, and pollution. One species in trouble is Anodonta californiensis, a native of the western U.S. These mussels are among the species that government officials are returning to Mountain Lake in San Francisco as part of a lake restoration project at the former Presidio military base.
Laboratory tests of the mussel’s ability to remove E. coli from water showed that it outperformed an EPA-approved filter at trapping E. coli. The mussel removed 90 percent of the bacteria from water pumped into aquariums, compared with no change in E. coli levels for aquariums using only the filters. The E. coli level in water is a significant monitoring parameter because it is a common indicator of the level of fecal contamination in the water.
Sources: Environmental Monitor & Chemical and Engineering News