Many types of microbial growth in water and on moist, humid surfaces is referred to as “water mold.” Growth and buildup in swimming pools, ponds, and pipes, for instance, is often generally described as mold. Scientifically speaking, however, water mold is a narrow class of microorganisms defined by reproduction, cellular makeup, and behavioral characteristics. True water mold belongs to the biological kingdom
Chytridomycota are single-cell organisms that thrive in water and in moist soil. Their cell wall is composed of chitin, a glucose-like substance. Oomycota are nearly identical in both form and habitat, except that their cell walls are made up of cellulose, which makes them tougher and more durable. Taken together, chtridomycota and oomycota are water mold.
Water molds develop from spores that find their way to wet and moist environments to develop and reproduce. Water molds reproduce both sexually and asexually. They feed on plant matter and other organisms.
In the soil, water molds can attack plant roots and kill of crops. Water mold is blamed for the Irish potato blight in the 1800s, and is one of the leading causes of oak tree death worldwide. In standing water, the molds cause ailments and death in fish. The molds also take root in moist wood, particularly in buildings that have suffered flood damage, water pipe leakage, or plumbing line failures. Water molds persist beneath the paint of walls, in insulation surrounding pipes, and in a building's frame. If regularly inhaled, mold spores can cause respiratory problems in both humans and animals.
Oomycota is also referred to as “downy mildew,” and it is usually oomycota that takes root in homes and other wooden structures. The durable cellulose “skin” of oomycota means that oomycota frequently takes up residence in wood and walls. Basement mold and mold in the moist walls of bathrooms is often oomycota. Water mold’s presence in a home is usually evidenced by a musty smell, black specks and splotches on walls and baseboards, and, in extreme circumstances, wood rot.
Not all bacterial growth in water or other moist areas is water mold. Most growth in swimming pools, for instance, is bacterial buildup, not real water mold at all. “White water mold” is a common swimming pool condition marked by buildups that in many instances resemble floating facial tissue. The reference to water mold is mistaken, however. Such buildups are colonies of bacteria known as “biofilms” that are comprised of neither chytridomycota nor oomycota. Rather, they are fungal growths that usually result from improper cleaning or irregular chlorine levels.
Water molds are naturally occurring, and there is no sure-fire way to eradicate them. Prevention is almost always the best course of action. In homes and buildings, prevention means ensuring that no areas are exposed to regularly damp conditions. Quickly addressing floods, keeping an eye out for leaks, and establishing proper air flow are all essential. For farmers and crop owners, application of fungicides can help prevent water molds, as can proper aeration of the soil. Once mold is found, everything the mold has touched must be abandoned, as the spores can spread and reproduce quickly.