A mucilage blob floats through shallow Adriatic waters in summer 2004 (Adriatic map
A mucilage begins as "marine snow": clusters of mostly microscopic dead and living organic matter, including some life-forms visible to the naked eye--small crustaceans such as shrimp and copepods (copepod picture
), for example.
Over time, the snow picks up other tiny hitchhikers--looking for a meal or safety in numbers--and may grow into a mucilage.
The blobs are also hot spots for viruses and bacteria, including the deadly E. coli,
a September 2009 study found. Coastal communities regularly test for the bacteria, and its presence is enough to close beaches to swimming.
"Now we see that
the release of pathogens from the mucilage can be potentially problematic" for human health, said study leader Roberto Danovaro, director of the marine science department at Polytechnic University of Marche in Italy.
Photograph courtesy M. Cornello