One of the biological challenges faces in the CAP canal is Cymbella, also known as rock snot. This microscopic diatom forms a polysaccharide stalk that is the consistency of gelatin when it is nutrient limited. When it dies, it sheds this stalk which then floats to the surface of the water, creating a mat. These mats are difficult to remove because they break apart as soon as large equipment comes in contact with them. Fortunately, Cymbella does not affect our ability to deliver water, and it is not harmful to animals or humans.